INJECTION AND INFUSION SITE TREATMENT DEVICES AND METHODS

Devices, kits and methods described herein are be used at chronic injection site or in conjunction with an indwelling catheter or cannula. A book-like packaging, applicator and/or tensioning device with an opening and optional indicia to align the catheter or cannula to the opening may be used to apply a dressing to a subject. The packaging, applicator and/or tensioning device may apply and/or maintain a strain in an elastic dressing.

BACKGROUND

Scar formation in response to cutaneous injury is part of the natural wound healing process. Wound healing is a lengthy and continuous process, although it is typically recognized as occurring in stages. The process begins immediately after injury, with an inflammatory stage. During this stage, which typically lasts from two days to one week (depending on the wound), damaged tissues and foreign matter are removed from the wound. The proliferative stage occurs at a time after the inflammatory stage and is characterized by fibroblast proliferation and collagen and proteoglycan production. It is during the proliferative stage that the extracellular matrix is synthesized in order to provide structural integrity to the wound. The proliferative stage usually lasts about four days to several weeks, depending on the nature of the wound, and it is during this stage when hypertrophic scars usually form. The last stage is called the remodeling stage. During the remodeling stage, the previously constructed and randomly organized matrix is remodeled into an organized structure that is highly cross-linked and aligned to increase mechanical strength.

While the histological features characterizing hypertrophic scars have been well documented, the underlying pathophysiology is not well known. Hypertrophic scars are a side effect of excessive wound healing, and generally result in the overproduction of cells, collagen, and proteoglycans. Typically, these scars are raised and are characterized by the random distribution of tissue bundles. The appearance (i.e., size, shape, and color) of these scars varies depending on the part of the body in which they form, and the underlying ethnicity of the person affected. Hypertrophic scars are very common, and may occur following any full thickness injury to the skin. Recently, it has been shown in U.S. Patent Application Publication 2006/0037091 (U.S. patent application Ser. No. 11/135,992 entitled “Method for Producing Hypertrophic Scarring Animal Model for Identification of Agents for Prevention and Treatment of Human Hypertrophic Scarring,” filed May 24, 2005) which is hereby incorporated by reference in its entirety, that mechanical stress may increase hypertrophic scarring in a murine model.

Keloids are typically characterized as tumors consisting of highly hyperplastic masses that occur in the dermis and adjacent subcutaneous tissue in susceptible individuals, most commonly following trauma. Keloids are often more severe than hypertrophic scars, since they tend to invade normal adjacent tissue, while hypertrophic scars tend to remain confined within the original scar border.

Scar tissue may also be formed from repetitive tissue injuries, such as patients who require repeated needle insertions for blood draws or injections or infusions of therapeutic agents for treatment of chronic health issues, including but not limited growth hormone injection, autoimmune diseases such rheumatoid arthritis, and diabetes, and also from other therapeutic or diagnostic procedures or devices that may utilize an indwelling catheter or needle.

BRIEF SUMMARY

Devices, kits and methods described herein may be for treatment of a subject at a skin site including without limitation for wound treatment or the treatment, amelioration, or prevention of scars and/or keloids, by manipulating mechanical or physical properties of skin or by shielding skin from stresses, and/or by controllably stressing or straining the epidermis and layers of dermal tissue at or near a skin site, i.e., at or adjacent a wound or a treatment site of a subject's skin.

Also, the impact of scar tissue formation are not limited to cosmetic effects. For example, diabetes patients may develop scar tissue and/or lipohypertrophy at chronic injections sites. Lipohypertrophy is an increased formation of fat tissue that is thought to be a hypertrophic effect from chronic localized insulin injections on adipose cells. The lipohypertrophy can adversely affect insulin injection or infusion rates due to structural changes in the tissue that can decrease the diffusion of insulin. Typical infusion using insulin pumps involves the placement of a cannula or needle into the delivery site (e.g., abdomen, arms, buttocks, thighs) every few days. Over time, this can induce lipodystrophic changes in the skin and subcutaneous structure, which can result in unpredictable or erratic insulin absorption. Eventually the patient may be limited in the available infusion sites on their body due to lipohypertrophy. Although, the effects of lipohypertrophy and lipodystrophy are thought to be induced by the insulin itself, it is hypothesized that tension offloading of the infusion location may also reduce this insulin effect, and may improve the variability and/or overall absorption rates at the infusion site. This may occur by reducing the formation of fibrosis, improving the vascularization, and/or reducing vascular resistance to perfusing the tissue under or about the insertion site. In some variations, it is hypothesized that the change in skin tension and/or the increased adhesive properties of the tensioned dressing or dressing component may extend the usable duration of the infusion set or sensor, e.g. from 2-3 days to 4 to 7 days. This may also result in a reduction of the size, surface area, depth and/or severity of inflammation at the injection/infusion site(s).

It is also believed that treatment of the injection and/or infusion sites of diabetes therapy may also have other effects separate from affecting the development of scar tissue or lipohypertrophy. For example, treatment of an injection site and/or injection at a site that has already been treated with a skin tensioning device may improve the dispersion of insulin at the injection site by altering the mechanical environment. For example, insulin leakage at the injection or infusion site may be reduced because of increased mechanical pressure at the skin surface, which may drive injected therapy deeper into the tissue because of the pressure gradient generated in the tissue by the tensioning device. This and other mechanical effects of skin tension treatment may result in an increased insulin bolus volume and/or surface area per unit injection. The mechanomodulation effects may results in improved insulin absorption, with a reduced average total daily, weekly and/or monthly insulin dosage, and/or improved daily, weekly and/or monthly time-in-range of blood glucose, with a reduced frequency or degree of hyperglycemia. The tensioning device may also reduce pain at the injection site, as a result of mechanomodulation of the nociceptors, and/or may reduce the risk of infection and/or pump alarms from occlusion, as a result of mechanically stabilizing the tissue.

According to variations, manipulating mechanical or physical properties may thereby modulate tensile or compressive stress at the skin site. The stress at the skin site may be reduced to levels below that experienced by normal skin and tissue. The stress at the skin site may be increased to levels above that experienced by normal skin and tissue. The stress or strain may be applied to surrounding tissue in one, two, or more directions to manipulate endogenous or exogenous stress at the skin site in one, two or more directions. According to variations, devices and methods described herein may reduce or otherwise manipulate the stress experienced by skin and/or a wound and surrounding tissues in order to treat a subject. The devices may also assist in preventing or reducing the incidence of wound dehiscence.

According to the devices, kits and methods described herein, a skin treatment device, skin device, wound treatment device, scar or keloid treatment device, scar or keloid amelioration or prevention device, bandage, or dressing may be provided that may be applied, attached to or coupled to one or more layers of the skin or tissue of a subject (hereinafter referred to as “dressing”, “skin device” or “skin treatment device”).

In addition to amelioration of scar formation, other uses for such skin treatment device may or may not include without limitation, for example, treating skin related conditions such as acne, blemishes, rosacea, warts, rashes (including but not limited to erythematous, macular, papular and/or bullous conditions), psoriasis, skin irritation/sensitivity, allodynia, telangiectasia, port wine stains and other arterio-venous malformations, and ectopic dermatitis; treating or improving existing scars, wrinkles, stretch marks, loose or sagging skin or other skin irregularities; lifting, pinning, holding, moving skin for various purposes such as during pre-operative preparation, during surgical procedures for example as a low-profile tissue retractor, to stabilize blood vessels during needle or catheter insertion, postoperatively, pre or post operatively for pre-treating or preconditioning skin for example, prior to scar revision, wound incision, body contouring, in mastectomy skin expansion, aesthetic skin treatment or resurfacing whether topical or subdermal, whether or not using an energy modality such as, for example, microwave, radio-frequency ablation, high-intensity focused ultrasound, laser, Infrared, incoherent light, during weight loss, or for aesthetic purposes; hair removal or hair loss; treating and/or closing skin injuries for example, incisions, wounds, chronic wounds, bed sores, ulcers (including venous stasis ulcers), preventing or reducing the incidence of wound dehiscence, diabetic skin or wound conditions, burn healing and/or relief; acting as an occlusive or negative-pressure wound dressing; protecting incisions or wounds, e.g. prevention of splitting or opening, protecting newborn belly buttons after cutting umbilical cord. Such treatments may include use of a drug or other therapeutic agent that may be applied to the skin with such device. The agents may include but are not limited to antibiotics, anti-fungals, immune modulators including corticosteroids and non-steroidal immune modulators. The agents may be provided in any of a variety of formulations, including but not limited powders, gels, lotions, creams, pastes, suspensions, etc. The devices may also be used for purposes of delivering a drug to the skin or through the skin, for example by stretching the skin and applying a drug thereto. Different configurations of the device may be amenable to the size or geometry of different body regions. The treatments may be applied to regions of any shape (e.g. linear, curved, stellate), size or depth, and to one or more regions of the body, including but not limited to the scalp, forehead, face (e.g. nose, eyelid, cheeks, lips, chin), ears, neck, shoulder, upper arm, lower arm, palm, dorsum of the hand, fingers, nailbed, axilla, chest, nipple, areola, back, abdomen, inguinal region, buttocks, perineal region, labia, penis, scrotum, thigh, lower leg, plantar surface of the foot, dorsal surface of the foot, and/or toes. Such devices may also be referred to herein as a “dressing”, “skin device” or “skin treatment device”.

In some situations, an immediate, quick or simple application of a dressing may be desired. Devices, kits and methods described herein may be for the preparation and/or application of a dressing to the skin and the separation of the applicator, tensioning device or dressing carrier, support or base from the skin device.

The devices, kits or methods described herein may include a packaging, carrier, support, base, applicator or tensioning device, each of which may: contain, hold, carry or support a dressing at least temporarily; may be used to prepare a dressing for application; may be used to deliver, orient or apply a dressing; may be used to maintain a dressing in a stressed or strained configuration; may be used to stress or strain a dressing; may be used to separate the dressing from the packaging, carrier, support, base, applicator or tensioning device and/or may be used during or after application of a dressing to provide additional treatment to a wound, incision or other treatment location; and/or may be used to apply pressure to a wound, incision or other treatment location. According to some variations, a packaging and/or applicator may provide structural support for a dressing while or after an adhesive liner is released. According to some variations, the assembly may be constructed to avoid folding or bending of the dressing to the extent that the adhesive on the dressing sticks to itself. For example, when some variations of the dressing are held or supported at one point or along one edge of the dressing in a cantilever configuration, the dressings will not bow, laterally deform, or otherwise deform out of plane, under their own mass or configuration.

In some other variations of the devices and methods herein, a device with a substantially rigid support structure or that provides structural support to a dressing and that provides a particular resistance to bending or column strength when two opposing edges of the device and support structure are placed under a compressive load that causes axial compression or lateral deformation, e.g. a force similar to a hand grasping force is applied to an edge of the device, before the device buckles or folds. For example, a resistance to bending may be characterized as the peak force that is achieve as the device and support structure are compressed without compressed by 25% of its original dimension. This column strength or rigidity may vary, depending upon the direction along the device and support structure being measured. In some further variations, the peak force may be at least about 0.02 Newtons per millimeter (N/mm), about 0.03 N/mm, about 0.05 N/mm, about 0.1 N/mm, about 0.15 N/mm, about 0.2 N/mm, about 0.3 N/mm, about 0.4 N/mm or about 0.5 N/mm. In some variations of devices comprising generally flat or planar devices and support structures having a thickness, the peak force may be measured by applying a compressive force along the shortest dimension of the device/support structure that is transverse to the thickness of the device/support structure. According to such variations, the device may have an aspect ratio of length to width that is greater than 1:1, 2:1 or 3:1, for example.

A resistance to bending in the direction of dressing strain may also be measured by three-point bending, applying a transverse force to the midpoint of the applicator simply supported on two outer points at a given distance apart or support span. For example, the distance between the two points of a sample may be approximately 0.75 inches and a force that ranges from about 1 to 1.25 pounds may be applied to a sample approximately 0.35 inches in width resulting in a deflection of approximately 0.05 inches. A resistance to bending may also be measured by characterizing the force at which buckling occurs on a simply supported beam. For example, a force of approximately 0.45 pounds may be applied to a simply supported sample approximately 0.35 inches in width and may result in a deflection of approximately 0.004 inches. The resistance to bending may also be characterized by the strain of the outer surface before fracture or permanent deformation. By taking measurements of the support structure and the deflections during the test procedure, a load deflection curve may be generated and the flexural modulus of the support structure may also be calculated. In some variations, the support structure may comprise a flexural modulus of at least about 0.9 GPa, while in other embodiments, the flexural modulus is at least about 1 GPa, at least about 1.1 GPa, at least about 1.2 GPa, at least about 1.3 GPa, or at least about 1.4 GPa.

In another example, a device of 7 cm wide by 19 cm long may be configured with a support structure comprising a paperboard, support sheet or support structure. The support structure may have an average thickness in the range of about 0.008″ to about 0.028″ or greater. In some specific variations, the support structure may have a thickness of about 0.012″, about 0.016″, about 0.018″, about 0.024″, about 0.28″ or about 0.032″, about 0.036″, about 0.04″, about 0.05″ or greater. Upon the application of force along the lengthwise edge of the 19 centimeter length, i.e. across the 7 cm width of the device, the support structure may provide sufficient rigidity or column strength to achieve peak forces of about 3 pound or more, 4 pounds or more, or of about 10 pounds or more, while being compressed, collapsed, bowed, buckled or otherwise deformed by 25% along its 7 cm width (i.e. about 1.75 cm). In some variations, the support structure may comprise scoring or regions of reduced thickness to permit some bending it at least one direction or in both directions.

According to some variations, a device that provides structural support may have a plurality or supporting cross elements or segments extending from one edge of the length to an opposing edge or the length (or from one edge of a width to an opposing edge of a width); According to some variations there may be three or more cross elements, e.g., a cross element extending along two opposing edges and transversely across a width (or a length) and one or more cross elements extending across the width (or length) and between the cross elements along the two opposing edges. Such cross elements may or may not be coupled or connected to each other, for example, with a relatively flexible material. Such cross elements may have a total aggregate width with respect to the length of an opposing edge of about 20% or more, about 25% or more, about 30% or more, or about 35% or more. According to some variations, one or more cross elements may be provided that have a total aggregate width, relative to the length of the opposing side, between about 20% to 100%. Such cross elements may be segmented and may provide flexibility when bending in a direction and rigidity relative to the flexibility, in another direction.

The packaging and/or applicator may also provide structural support or stability of the dressing as it is oriented and/or applied to the skin of a subject. According to some variations, the dressing and packaging is configured to be pre-oriented in a position facing a wound before or after the wound device is prepared for application, e.g., the adhesive liner is removed. According to some variations, the packaging or applicator is configured to be used with one hand to orient and/or apply the device to the skin of a subject. For example, in some situations, particularly where a longer or larger dressing is used, a packaging or applicator provides structural support for a dressing such that a user can effectively hold onto, manipulate and/or apply a prepared dressing with one-hand. According to some variations, the assembly comprises a support structure. A dressing support structure is defined herein to mean a structure that is coupled whether directly or indirectly, to a back surface of a dressing that is to be applied to a subject. The support structure may further comprise at least in part, a material or structure that is more rigid than the dressing to be applied to a subject. The support structure may comprise one or more elements or segments. It may be constructed of a single substrate, a laminate or a plurality of elements coupled together and/or to the dressing. According to some variations at least 20%, 25%, 30%, 35%, or 40% of a length or width of the dressing is supported by one or more support structures extending from a first opposing side to an opposite side along a length or width of the dressing. In some further variations, the percentage of a length or width that is supported by the support structure(s) is a minimum average of support across the entire length or entire width of the device, e.g. at least a 20%, 25%, 30%, 35% or 40% average support across an entire dimension of the device, e.g. length or width. According to some variations, an entire area of a dressing is supported by a support structure. According to some variations, a base, carrier or support of a dressing may comprise at least three support structures extending transversely between opposing sides of the dressing. According to some variations, a support structure comprises interconnected members or elements. According to some variations, a base, carrier or support remains coupled to the dressing as it is applied. According to some variations, greater structural support is provided to a dressing carrier, support or base in a first direction while greater flexibility is provided in a second direction, while lesser flexibility is in the first direction and lesser structural support is provided in the second direction. According to some variations, one or more support structures may extend beyond an edge of the first opposing side. According to some variations, one or more support structures, at least in part, may extend beyond at least a portion of an edge of a first opposing side and at least in part beyond at least a portion of an edge of an opposite side. According to some variations, a support structure may extend at least 3 mm from at least a portion of an edge of the dressing. According to some variations, the packaging or applicator is configured to improve a sterile transfer of a dressing to a wound of a subject. According to variations, the packaging or applicator may be sufficiently wider or longer, or have a sufficiently larger area than a dressing providing the ability to maneuver or manipulate the support or applicator so that it provides sterile application and/or one-handed application without the need to touch the dressing. According to some variations, a margin of distance is provided from the outer edges of the dressing carrier, support or base to the dressing supported on the base or adhesive on the dressing. Such margins may be selected to prevent or resist a user from touching the dressing or dressing adhesive when grasping the edges to manipulate the dressing carrier, support, applicator or base.

Devices, kits and methods described herein may be for the treatment, amelioration, or prevention of scars and/or keloids by creating and/or maintaining a pre-determined strain in an elastic skin treatment device that is then affixed to the skin surface using skin adhesives to transfer a generally planar(e.g. compressive) force from the bandage to the skin surface.

In some variations, a dressing is provided, comprising an elastic sheet structure (e.g., a comprising a silicone polyurethane, TPE (thermoplastic elastomers), synthetic rubber or co-polyester material) comprising an upper surface, a lower surface, a first edge and a second edge opposite the first edge, and one or more adhesive regions. The dressing may further comprise a first release liner releasably attached to the adhesive region or regions. The adhesive region(s) may comprise a pressure sensitive adhesive. The dressing may be tapered or otherwise shaped to reduce skin tension at the edges. The dressing may have modified, reduced or no adhesive near its edges to reduce skin tension at the edges. Portions of the dressing may be unstrained and may thereby reduce strain in certain areas of the skin where the dressing is applied. In some specific examples, the unstrained area or areas are found between the edges of the dressing and the strained area(s). In some further examples, the unstrained areas are limited to this area and are not found, during application or use, between the strained areas of a single dressing, in use. In still further examples, the unstrained areas are limited to areas along the edges of a dressing that intersect the strain axis of the strained area(s), but not to areas along the edges of the dressing that are generally parallel to the strain axis.

A packaging device, dressing carrier, dressing support, dressing base, applicator and/or tensioning device may be provided. The packaging device, dressing carrier, dressing support, dressing base, applicator and/or tensioning device may be configured to stress and/or strain a dressing prior to application to a subject. A device may be used to strain and/or maintain a strain on a dressing. In one variation, a dressing is provided, comprising a first device attachment structure, zone or region, a second device attachment structure, zone or region, and a structure or mechanism configured to exert a separation force between the first and second device attachment structures, zones or regions. The device may further comprise a releasable locking mechanism, attachment mechanism or adhesive, configured to maintain the member or mechanism in a strained configuration.

In some situations, application of a compressive force to a wound is desirable to reduce bleeding. According to some variations, the packaging, carrier, support, base, applicator or tensioning device described herein may be further used to help reduce bleeding, e.g., by allowing application of a compressive force using the device while or after the dressing is applied. A coagulative additive may also be provided on a dressing.

According to one aspect, the packaging, carrier, support, base, applicator and/or tensioning device may be sufficiently rigid or supportive in at least one direction, to hold a dressing's form so that it is easy to manipulate.

According to some variations, the packaging is also sufficiently flexible in at least one direction to permit curving or shaping of the dressing to conform to the curvature or shape of the location on the body or skin where the dressing is applied. Generally, the flexibility of the packaging used to conform the dressing to the treatment site may be configured so that the treatment site is not substantially deformed during the application of the dressing ; so that the application of the dressing is relatively smooth or uniform on the skin; and/or provides a uniform, predetermined, or relatively predictable strain or force to an area of skin The packaging or applicator may have flexibility in a first direction and greater rigidity in another direction. The packaging or applicator may include elements or segments that permit flexibility with respect to adjacent elements or segments.

According to some variations, the packaging is also sufficiently flexible in at least one direction to permit curving or shaping of the dressing to conform to the curvature or shape of the location on the body or skin where the dressing is applied. Generally, the flexibility of the packaging used to conform the dressing to the treatment site may be configured so that the treatment site is not substantially deformed during the application of the dressing; and/or so that the application of the dressing is relatively smooth or uniform on the skin; and/or provides a uniform, predetermined, or relatively predictable strain and/or force to an area of skin. The packaging or applicator may have flexibility in a first direction and greater rigidity in a second direction. The first direction may be transverse to the direction of straining or have a component that is transverse to the direction of straining. The second direction may by the direction of straining or have a component that is in the direction of straining. The first direction may or may not be transverse with respect to the second direction. The packaging or applicator may include elements or segments that permit flexibility with respect to adjacent elements or segments.

According to some variations a desired flexibility, for example having at least one component transverse to the direction of straining, may be characterized by a modified cantilevered beam bending model, i.e. applying a force to the free end of a beam, simply supported from the other end, while wrapping it around a cylindrical object with a known radius of curvature or curvature, defined as the reciprocal of the radius of the curvature. According to one variation, the force to bend the packaging or applicator around an object with a predetermined curvature may be no greater than about 3 pounds. According to one variation, the force may be no greater than about 0.3 pounds. According to one variation, the force to bend around a predetermined curvature of about a 2.5 inch radius may be no greater than about 3 pounds. In another variation, the force to bend around a predetermined curvature of about a 2.5 inch radius may be no greater than about 0.3 pounds.

According to some variations, a packaging, applicator or tensioning device is provided comprising a base having an inner surface to which a dressing is removably attached, and a cover or lid having an inner surface interfacing the inner surface of the base when in an initial closed configuration. According to some variations, the base and cover are coupled at corresponding edges along their corresponding lengths to form a book-like structure whereby the cover may be rotated with respect to the base to open the device. Alternatively the cover may be lifted off of the base. According to variations, a liner is attached to the cover and will expose an adhesive side of a dressing when the cover is lifted or opened.

In some variations, the book-like structure, in the closed configuration, comprises a layered structure comprising a cover/lid, a treatment device and a base, in that relative order, while in the open configuration, the relative order of the layered structure changes to a cover/lid, a base, and a treatment device. The treatment device may also comprise one or more release layers. In one variation, in the closed configuration, a first face of the cover/lid is in contact with a first face of the treatment device, and a first face of the base is in contact with the second surface of the treatment device opposite the first surface, while in the open configuration, a second face of the cover/lid (opposite the first face of the cover/lid) is in contact with a second face of the base (opposite the first face of the base) but not with the first face of the treatment device. In some variations, the cover/lid may be separated from the base during or after tensioning of the treatment device. In some variations, the treatment device may be attached asymmetrically to the book-like structure, relative to the bending region of the book-like structure. In some instances, the asymmetric attachment may provide the user with a mechanical advantage when tensioning the dressing, and/or may reduce manufacturing costs by optimizing the amount of elastic material used in the dressing. In other variations, the dressing or skin treatment device may be attached symmetrically to the book-like structure, relative to the bending region of the book-like structure.

In another embodiment, a method of applying a dressing to a surface is provided. According to some variations the method may comprise providing a dressing packaging comprising: an applicator comprising a base structure having an inner surface and a manipulation portion; a dressing comprising a first surface configured to be applied to a skin or wound of a subject; and a back surface, wherein the back surface of the dressing is removably coupled or anchored to the inner surface of the base structure, and wherein the first surface faces away from the inner surface of the base structure; and a cover configured to removably cover the first surface of the dressing. A method may further comprise removing the cover to expose a first surface of a dressing; and using the manipulation portion of the base structure to apply the first surface of the dressing to a wound or skin of a subject. In another variation, a method for treating a wound is provided, comprising straining an inner region of an elastic bandage between a first unstrained region and a second unstrained region, and attaching at least the strained inner region of the dressing to a skin site or both strained and unstrained regions.

According to some variations, a dressing packaging assembly comprises: a base structure having an inner surface; a cover structure having an opposing surface, wherein the base structure is movably coupled to the cover structure; and a dressing comprising a first surface configured to be applied to a wound or skin of a subject, and a back surface, wherein at least a portion of the back surface is removably coupled to the inner surface of the base structure; and wherein the cover structure is configured to move from a first position where the opposing surface interfaces with and is substantially parallel to the first surface to the dressing to a second position where the opposing surface is separated from the first surface of the dressing. According to variations, the first surface of the dressing comprises an adhesive region. According to variations the first surface of the dressing comprises an adhesive backing interfacing an adhesive region on the dressing. According to variations, the opposing surface of the cover structure comprises an adhesive backing covering the adhesive region when the cover structure is in the first position and separated from the adhesive region when the cover structure is in the second position. According to variations, the dressing comprises an elastic material. According to variations, the dressing comprises a first attachment region coupled to the inner surface of the base structure and a second attachment region coupled to the opposing surface of the cover structure, wherein the cover and base are configured to exert a straining force to strain the dressing when the cover is moved from the first position to the second position. According to variations, a tensioning structure is configured to exert the straining force on the dressing. According to variations, the tensioning structure comprises: a first structure configured to couple the dressing at the first attachment region to the inner surface of the base structure; and a second structure configured to couple the dressing at the second attachment region to the opposing surface of the cover; wherein the tensioning structure is configured to exert the straining force to the dressing between the first attachment region and the second attachment region when the cover structure is moved with respect to the base structure from the first position to the second position. According to some variations, the dressing has a first width when the cover is in the first position and a second width when the cover is in the second position, wherein the second width is greater than the first width. According to variations, the second width is at least 20% greater than the first width. According to variations, the second width is at least 40% great than the first width. According to variations, the base structure comprise at least one relatively rigid element and at least one relatively flexible element, wherein the relatively rigid element is sufficiently rigid to support the dressing when the straining force is applied in a first direction; and wherein the relatively flexible element permits the base structure to flex in a second direction. According to variations, the at least one relatively rigid element comprises a plurality of flexible coupled, relatively rigid elements. According to variations, the cover structure comprises at least one relatively rigid element and at least one relatively flexible element. According to variations, a release device is configured to release the dressing from the base structure after the dressing is applied to a wound or skin of a subject. According to some variations, base structure is pivotably coupled to the cover structure.

According to variations, a dressing packaging assembly comprises: a base structure having an inner surface and comprising at least one support element and at least one flexible element; and a dressing comprising a first surface configured to be applied to a wound or skin of a subject, and a back surface, wherein at least a portion of the back surface is removably coupled to the inner surface of the base structure. According to variations, the at least one rigid element comprises a plurality of rigid elements coupled to each other with the at least one flexible element. According to variations, a cover structure comprises an opposing surface configured to interface with the first surface of the dressing, wherein the cover structure is movably coupled to the base structure to move from a first position where the opposing surface interfaces with the first surface of the dressing, to a second position where the cover is separated from the first surface of the dressing. According to variations, the cover structure is pivotably coupled to the base structure. According to variations, the cover structure comprises at least one support element and at least one flexible element sufficiently flexible to permit shaping of the cover structure. According to variations, the first surface of the dressing comprises an adhesive region. According to variations, the first surface of the dressing comprises an adhesive backing interfacing an adhesive region on the dressing. According to variations, the opposing surface of the cover structure comprises an adhesive backing covering the adhesive region in the first position and separated from the adhesive region in the second position. According to variations, the dressing comprises and elastic material. According to variations, the dressing comprises a first attachment region coupled to the inner surface of the base structure and a second attachment region coupled to the opposing surface of the cover structure, wherein the cover and base are configured to exert a straining force to strain the dressing when the cover is moved from the first position to the second position. According to variations, the assembly further comprises a tensioning structure configured to exert the straining force on the dressing. According to variations, the tensioning structure comprises: a first structure configured to couple the dressing at the first attachment region to the inner surface of the base structure; and a second structure configured to couple the dressing at the second attachment region to the opposing surface of the cover wherein the tensioning structure is configured to exert the straining force to the dressing between the first attachment region and the second attachment region when the cover structure is moved with respect to the base structure from the first position to the second position. According to variations, the dressing between the first and second attachment regions has a first width when the cover is in the first position and a second width when the cover is in the second position, wherein the second width is greater than the first width. According to variations, the second width is at least 4% greater than the first width. According to variations, the second width is at least 20% greater than the first width. According to variations, the second width is at least 40% great than the first width.

According to variation, a method of applying a dressing to a wound or skin of a subject comprises: providing a dressing packaging assembly comprising: a base structure having an inner surface; a cover structure having an opposing surface, wherein the base structure is movably coupled to the cover structure; and a dressing comprising a first surface including an adhesive region, and a back surface, wherein at least a portion of the back surface is removably coupled to the inner surface of the base structure, and wherein the opposing surface of the cover structure comprises an adhesive backing covering the adhesive region when the cover structure is in the first position; pivoting the cover structure with respect to the base structure to a second position to separate the opposing surface from the first surface of the dressing and to separate the adhesive backing from the adhesive region; applying the first surface of the dressing to a wound or skin of a subject, then subsequently releasing the dressing from the base structure. According to variations of the method, at least a portion of the back surface of the dressing is coupled to the cover structure and further comprising pivoting the cover structure with respect to the base structure to strain the dressing.

According to variations, a dressing applicator comprises a first dressing attachment region and a second dressing attachment region comprising a variable separation distance between the first dressing attachment region and the second dressing attachment region, and a bending region between the first dressing attachment region and the second dressing attachment region that alters the variable separation distance, and wherein a first distance from a center of the bending region to the first dressing attachment area is different from a second distance from the center of the bending region to the second dressing attachment area.

According to variations, a dressing tensioning device comprises: a dressing carrier comprising a first carrier edge and a second opposing carrier edge defining a carrier width therebetween; a tensioning element configured to move with respect to the dressing carrier from a first position to a second dressing tensioning position; and a dressing assembly comprising a dressing including a first dressing edge coupled to the carrier adjacent the first carrier edge; a second dressing edge coupled to an attachment element wherein the attachment element coupled to the tensioning element; wherein in the first position of the tensioning element, the second dressing edge is a first distance from the second carrier edge within the width of the carrier, and in the second position of the tensioning element, the second dressing edge is a second distance from the second carrier edge within the width of the carrier, wherein the first distance is greater than the second distance. According to variations, the first dressing edge is relatively fixed with respect to the second dressing edge when the tensioning element is moved between the first and second positions.

According to variations, a dressing packaging assembly comprises: a base structure having an inner surface; a cover structure having an opposing surface, wherein the base structure is movably coupled to the cover structure; and a dressing comprising a first surface configured to be applied to a wound or skin of a subject, and a back surface, wherein at least a portion of the back surface is removably coupled to the inner surface of the base structure; wherein the cover structure is configured to move from a first position where the opposing surface interfaces with the first surface to the dressing to a second position where the opposing surface is separated from the first surface of the dressing where the second position is at least about 180 degrees rotated with respect to the first position. According to variations, the first surface of the dressing comprises an adhesive region. According to variations, the first surface of the dressing comprises an adhesive backing interfacing an adhesive region on the dressing. According to variations, the opposing surface of the cover structure comprises an adhesive backing covering the adhesive region when the cover structure is in the first position and separated from the adhesive region when the cover structure is in the second position. According to variations, the dressing comprises an elastic material. According to variations, the dressing comprises a first attachment region coupled to the inner surface of the base structure and a second attachment region coupled to the opposing surface of the cover structure, wherein the cover and base are configured to exert a straining force to strain the dressing when the cover is moved from the first position to the second position. According to variations, the assembly further comprises a tensioning structure configured to exert the straining force on the dressing. According to variations, the tensioning structure comprises: a first structure configured to couple the dressing at the first attachment region to the inner surface of the base structure; and a second structure configured to couple the dressing at the second attachment region to the opposing surface of the cover; wherein the tensioning structure is configured to exert the straining force to the dressing between the first attachment region and the second attachment region when the cover structure is moved with respect to the base structure from the first position to the second position. According to variations, the dressing has a first width when the cover is in the first position and a second width when the cover is in the second position, wherein the second width is greater than the first width. According to variations, the second width is at least 20% greater than the first width. According to variations, the second width is at least 40% great than the first width. According to variations, the base structure comprises at least one relatively rigid element and at least one relatively flexible element, wherein the relatively rigid element is sufficiently rigid to support the dressing when the straining force is applied in a first direction; and wherein the relatively flexible element permits the base structure to flex in a second direction.

According to variations, a dressing packaging comprises: a dressing carrier comprising a first carrier edge, a second carrier edge opposing the first carrier edge, and a support structure extending between the first edge and the second edge, configured to support a dressing during application of the dressing to a subject; and a dressing comprising a first dressing edge, a second dressing edge opposing the first dressing edge, a back surface and an opposing skin interfacing surface, wherein at least a portion of the back surface is removably coupled to the dressing carrier wherein the first dressing edge and the second dressing edge are positioned between the first carrier edge and the second carrier edge, and wherein the first dressing edge defines a first margin between the first dressing edge and the first carrier edge and the second dressing edge defines a second margin between the second dressing edge and the second carrier edge, wherein each of the first and second margins have a width of at least three millimeters.

In one variation, a dressing system is provided, comprising a first support, a second support, and a primary bending region therebetween, the primary bending region comprising a primary bending axis, and a treatment device comprising a first attachment region attached to the first support and a second attachment region attached to the second support, a first separation region configured to separate from first attachment region and a second separation region configured to separate from the second attachment region. The first and second separation regions may comprise perforations. The dressing system may further comprise a pull element located along the perforations. The treatment device may be asymmetrically attached to the first and second supports, relative the primary bending region. A first distance between the first support and the primary bending axis may be different from a second distance between the second support and the primary bending axis. The dressing system may further comprise a closed configuration wherein the treatment device is located between the first support and the second support, and a closed configuration wherein the second support is located between the first support and the treatment device. The second support may comprise at least one secondary bend region comprising a secondary bending axis that is not parallel to the primary bending axis. The secondary bending axis may be orthogonal to the primary bending axis. The first support may comprise at least one secondary bend region comprising a secondary bending axis that is not parallel to the primary bending axis. The at least one secondary bend region of the first support may be aligned with the at least one secondary bend region of the second support. The treatment device may further comprise a release liner coupled to an adhesive surface of the treatment device. The treatment device may comprise a perforation region. The dressing system may further comprise an elongate element attached adjacent to the perforation region. The elongate element may protrude beyond the perforation region of the treatment device. In some variations, at least a portion of the elongate element may be folded, and the fold may be along a substantial length of the treatment device. At least one of the first and second supports may comprise indicia identifying a center region of the treatment device. The indicia may comprise a recessed edge, ink mark, embossing, or window. The primary bending region may also perforated. The first support may be configured to detach from the second support and the treatment device, and may or may not do so while maintaining the treatment device in a strained configuration. The second support may comprise an adhesive element configured to adhere to the treatment device when the dressing system is in the open configuration but not in the closed configuration. The first support may comprise an attached release liner. The release liner may be attached to the first support between an outer edge of the first support and the attached treatment device. An inner surface of the first and/or second support facing the treatment device may include an adhesive, such as an adhesive coating or adhesive tape, which is configured to maintain the treatment device either in a tensioned state as it is stretched and contacts the adhesive, and/or to maintain the treatment device against the first and/or second supports.

In another variation, a dressing system is provided, comprising a first tensioning member, a second tensioning member, and a primary bending region therebetween, the primary bending region comprising a primary bending axis, and a treatment device asymmetrically attached to the first and second tensioning members, relative the primary bending region. The treatment device may comprises a first end attached to the first tensioning member and a second end attached to a second tensioning member, wherein a first distance between the first tensioning member and the primary bending axis is different from a second distance between the second tensioning member and the primary bending axis. The dressing system may further comprise a closed configuration wherein the treatment device is located between the first tensioning member and the second tensioning member, and an open configuration wherein the second tensioning member is located between the first tensioning member and the treatment device. The second tensioning member may comprise at least one secondary bend region comprising a secondary bending axis that is not parallel to the primary bending axis. The secondary bending axis may be orthogonal to the primary bending axis. The first tensioning member may comprise at least one secondary bend region comprising a secondary bending axis that is not parallel to the primary bending axis. The at least one secondary bend region of the first tensioning member may be aligned with the at least one secondary bend region of the second tensioning member. The treatment device may further comprise a release liner coupled to an adhesive surface of the treatment device. The treatment device may comprise a perforation region. The dressing system may further comprise an elongate element attached adjacent to the perforation region. The elongate element may protrude beyond the perforation region of the treatment device. In some variations, at least a portion of the elongate element may be folded, and the fold may be along a substantial length of the treatment device. At least one of the first and second tensioning members may comprise indicia identifying a center region of the treatment device. The indicia may comprise a recessed edge, ink mark, embossing, or window. The primary bending region may be perforated. The first tensioning member may be configured to detach from the second tensioning member and the treatment device. The first tensioning member may be configured to detach from the second tensioning member and the treatment device while maintaining the treatment device in a strained configuration. The second tensioning member may comprise an adhesive element configured to adhere to the treatment device when the dressing system is in the open configuration but not in the closed configuration. The first tensioning member may comprise an attached release liner. The release liner may be attached to the first tensioning member between an outer edge of the first tensioning member and the attached treatment device.

In another variation, a dressing system is provided, comprising a first applicator member, a second applicator member, and a primary bending region therebetween, the primary bending region comprising a primary bending axis, and a treatment device attached to the first and second applicator members, wherein the dressing system comprises a closed configuration wherein the treatment device is located between the first applicator member and the second applicator member, and a closed configuration wherein the second applicator member is located between the first applicator member and the treatment device. The second applicator member may comprise at least one secondary bend region comprising a secondary bending axis that is not parallel to the primary bending axis. The secondary bending axis may be orthogonal to the primary bending axis. The first applicator member may comprise at least one secondary bend region comprising a secondary bending axis that is not parallel to the primary bending axis. The at least one secondary bend region of the first applicator member may be aligned with the at least one secondary bend region of the second applicator member. The treatment device may further comprise a release liner coupled to an adhesive surface of the treatment device. The treatment device may comprise a perforation region. The dressing system may further comprise an elongate element attached adjacent to the perforation region. The elongate element may protrude beyond the perforation region of the treatment device. At least a portion of the elongate element may be folded, and the fold may be along a substantial length of the treatment device. At least one of the first and second applicator members may comprise indicia identifying a center region of the treatment device. The indicia may comprise a recessed edge, ink mark, embossing, or window. The primary bending region may be perforated. The first applicator member is configured to detach from the second applicator member and the treatment device. The first applicator member may be configured to detach from the second applicator member and the treatment device while maintaining the treatment device in a strained configuration. The second applicator member may comprise an adhesive element configured to adhere to the treatment device when the dressing system is in the open configuration but not in the closed configuration. The first applicator member may comprise an attached release liner. The release liner may be attached to the first applicator member between an outer edge of the first applicator member and the attached treatment device.

Devices kits and methods herein may include a support, packaging and/or applicator configured to maintain a pre-strained dressing in a strained configuration for a period of time after straining and prior to application to skin of a subject. Devices and methods herein may include a method of manufacturing such a pre-strained dressing.

According to one variation, a pre-strained and strain shielded dressing assembly may be stored for a period of time after straining and prior to use. In some variations, the dressing may be configured to maintain a predictable and/or desired amount of tensile force during a pre-determined period of time after initial straining. In some variations, the dressing may be configured to lose a predetermined maximum and/or minimum amount of tensile force (measured in a direction of tensile straining of the dressing) during one or more periods of time.

A desired time for application of the dressing to a subject may be when the dressing, in its pre-strained and strain shielded configuration, has a tensile force characteristic or range thereof that is desired. Such desired range may be selected to provide sufficient modulation of the forces on the skin to treat the skin while avoiding or minimizing disruption irritation to the skin. As noted herein, for a given dressing, different levels of stress or strain may be imparted to the skin at different locations and/or on different subjects. Also different levels of force offloading may be desirable for different individuals or different locations on a subject's skin. Thus different ranges of dressing force properties may be appropriate for different skin treatment applications.

Such desired force range may be selected based on a determination desired force properties to be applied to a particular subject, portion of skin and/or for a particular skin treatment purpose. Such desired force may be high enough to provide a therapeutic mechanomodulation of the skin while be low enough to prevent significant skin irritation.

Force properties of a pre-strained dressings may vary over time. An initial strain may be applied to the dressing where the elastic material or other structure, of the dressing has an initial tensile force characteristic. The dressing may be maintained in a strained configuration at a particular strain level after it is pre-strained for an initial period of time. During the initial period of time, the force properties of the elastic material may diminish, decay or exhibit a loss of force. After an initial predetermined period of time, the force properties of the elastic material may reach, diminish to or decay to a desired force level and/or range of force levels. The dressing elastic material force characteristics may be within the desired range for at least a subsequent period of time. In some variations, the dressing material may have an elastic modulus in the range of about 1 MPa to about 15 MPa, sometimes about 1.5 MPa to about 6 MPa, and other times about 2 MPa to about 5 MPa, about 3 MPa to about 4 MPa, or about 3.5 MPa to 5 MPa, while having a peak load per width up to a 0.6 strain of less than 3 N/mm, sometimes less than about 2.5 N/mm, sometimes less than 2 N./mm, sometimes less than 1 N/mm, sometimes less than about 0.75 N/mm and other times less than about 0.6 N/mm or less than about 0.5 N/mm. The peak load per width up to a 0.6 strain, may be at least about 0.35 N/mm, sometimes at least about 0.5 N/mm, and other times at least about 0.6 N/mm, 0.7 N/mm, 0.8 N/mm, 0.9 N/mm or 1 N/mm. The material may be selected such that the material, at a constant engineering strain of 20%, is able to maintain an engineering stress of at least about 200 kPa, 250 kPa, 300kPa, 400 kPa, or 500 kPa, 1000 kPa, 1500 kPa, 2000 kPa, 2500 kPa, 3000 kPa or more for at least 8 hours with less than a 10% or 5% variation or decrease in engineering stress.

According to a variation, for example, the initial force or strain properties of a dressing may be selected so that the desired range of force values occur during a period of time where the percentage loss of force is reduced and occurs over a longer period of time.

The initial strain and/or force level of the dressing may be selected so that the time of use falls within a desired time frame or period based on the percentage loss of force of the dressing over time.

According to variations, the dressing may be initially strained or over-stressed to provide a greater initial force per unit width than that of a desired range at the time of application to skin. According to variations, the initial strain and resulting initial force per width of a dressing may be selected based on desired final and resulting force properties and/or a desired time frame for use of the dressing. Such initial strain level may be, for example, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 100% or more. According to variations, the initial force is greater than a desired force range. Such initial force level may be for example about or up to 25%, about or up to 35%, about or up to 50%, about or up to 75% or more than the desired force at time of application of the dressing. Such initial force level may be but is not limited to, for example, between 2 and 5 Lbf/inch, 1.54 and 3.85 Lbf/inch, 1.33 and 3.33 Lbf/inch. or 0.85 to 2.20Lbf/inch

According to variations, a dressing may be configured to be initially strained or tensile stressed to a desired strain or force level and maintained in the strained configuration for an initial time frame. According to variations, the initial time frame may be, for example, 1 hour or more, 1 day or more, 1 week or more, or up to 1 month or more prior to application. According to variations, the initial time frame may be 1 hour or more, 1 day or more, 1 week or more, or up to 1 month or more in a material pre-conditioning state prior to final assembly or manufacture. Such preconditioning state may be straining the material at a constant strain or straining the material at varied levels of strain.

Then according to some variations, for the duration of a subsequent pre-determined time frame after the initial time frame, the dressing may be configured to maintain a desired minimum final force or force range. During the subsequent time frame, the device may be applied to a subject's skin for treatment. Such desired force range may be from about 0.5 to 1.0 Lbf/inch, 1.0 to 2.5 Lbf/inch or from about 1.6 to 2.1 Lbf/inch. The force loss during the subsequent time period may be up to 3%, up to 5%, up to 8%, up to 10%, up to 15%, up to 20%, up to 25% or more. The duration of the subsequent time period may be, for example 2 months, or more 3 months or more, 6 months or more, 12 months or more, 36 months or more, or 48 months or more.

The pre-strained dressing may then be coupled to a strain maintaining element during an initial period of time. The strain maintaining element may remain on the dressing during a portion of the subsequent period of time until it is used.

According to a variation for example, the average initial force or strain properties (average may include or may comprise an average, for example, per manufacturing lot, or a specified average within a given tolerance level) of a dressings pre-strained at manufacturing may be provided so that the desired range of average force values occur during a period of time where the average percentage loss of force is reduced and occurs over a longer period of time. In other variations, the pre-straining is initiated at the point-of-use. In still other variations, a portion of the pre-straining is performed at the point-of-manufacture, and additional straining or strain relief is performed at the point-of-use. After pre-straining, the dressing may then be packaged, sealed and sterilized for future use.

The initial average strain and/or force level of the dressings may be selected so that the time of use falls within a desired time frame or period based on the average percentage loss of force of the dressings over time.

According to variations, the dressings may be initially strained or over-stressed to provide a greater average initial force per unit width than that of a desired range at the time of application to skin. According to variations, the average initial strain and resulting initial force per width of a dressing may be selected based on desired final and resulting force properties and/or a desired time frame for use of the dressing. Such average initial strain level may be, for example, less than 20%, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 100% or more. According to variations, the average initial force is greater than a desired force range. Such average initial force level may be for example about or up to 25%, about or up 35%, about or up to 50%, about or up to 75%, or more than the desired force at the time of application of the dressing. Such average initial force level may be but is not limited to, for example, between 2 and 5 Lbf/inch, 1.54 and 3.85 Lbf/inch, 1.33 and 3.33 Lbf/inch. or 0.85 to 2.20Lbf/inch

According to variations, a dressing may be configured to be initially strained or tensile stressed to a desired average strain or force level and maintained in the strained configuration for an initial time frame. According to variations, the initial time frame may be 1 hour or more, 1 day or more, 1 week or more, or up to 1 month or more prior to application. According to variations, the initial time frame may be 1 hour or more, 1 day or more, 1 week or more or up to 1 month or more in a material pre-conditioning state prior to final assembly or manufacture. Such preconditioning state may be straining the material at an average constant strain or straining the material at varied levels of average strain.

Then according to some variations, for the duration of a subsequent pre-determined time frame after the initial time frame, the dressings may be configured to maintain a desired minimum average final force or average force range. During the subsequent time frame, the devices may be applied to a subject's skin for treatment. Such desired average force range may be from about 0.5 to 1.0 Lbf/inch, 1.31 Lbf/inch to 1.41 Lbf/inch. The average force loss during the subsequent time period may be up to 3%, up to 5%, up to 8%, up to 10%, up to 15%, up to 20%, up to 25% or more. The duration of the subsequent time period may be, for example 2 months or more, 3 months or more, 6 months or more, 12 months or more, 36 months or more, or 48 months or more.

A pre-strained dressing may be coupled to a strain maintaining element during an initial period of time during one or more manufacturing steps. The strain maintaining element may remain on the dressing during a portion of the subsequent period of time during manufacturing or in transport or storage until it is used.

Example I below illustrates a percent change in force per unit width of selected pre-strained dressings maintained at a constant strain for a period of time under testing conditions.

In this example, five (5) dressings were strained at 40% and 5 dressings were strained at 60%. The dressings were constructed of MED 82-5010-10 by NUSIL TECHNOLOGY LLC (Carpenteria, Calif.). A maximum of 5 particulates per sheet less than or equal to 0.020″ and a maximum of 5 surface gels and/or bubbles per sheet a size no greater than 0.020″ were present in the samples. The samples were initially 8″ (+−0.02″) X 1″ (+−1″) with a thickness of 0.010″. The samples had a durometer value of about 50 (Shore A scale), a tensile strength of about 1,450 psi, elongation of about 1000% and a specific gravity of about 1.16. Six inch (6″) centered gage marks were added. The 40% strain samples' gage lengths increase to 8.4″ when strained. The 60% strain samples' gage lengths increase to 9.6″ when strained. The samples were attached in a strained configuration to sample fixtures or clamps with a locking bar between the sample fixtures. Samples fixtures were constructed of Acrylic (PMMA) and coated with an anti-skid tape. When tested, the ends of the sample fixtures were attached to grips of a Tensile Tester Chatillon Model TCD225, 50 LBF load cell. Measurements were then taken after releasing the locking bar. The samples were stored in the test lab at ambient lab temperatures for the duration of the test. The tensile forces of the dressings were measured at various time intervals.FIG.6illustrates the percent loss of force over time for each of the dressings. An initial average post strain loss after one hour at 60% strain was about 30% and after 1 hour at 40% strain was about 25%. Following the initial post strain loss, it was surprising that the additional loss after the initial loss decreased at a slower rate and was on average was about 15% for a period of 2 years (total of 45% loss average).

In other examples, the maximum number of particulates per sheet may be 1, 5, 10, 20 or 25 or more, with a 0.01″, 0.02″, 0.040″, 0.050″ or 0.07″, or 0.1″ maximum size, and the maximum number of surface gels and/or bubbles may be 1, 5, 10, 20 or 25 or more, with a0.01″, 0.02″, 0.040″, 0.050″ or 0.07″, or 0.1″ maximum size. In other variations, the dressing material may have a durometer value of about Shore A 15 to about 90, sometimes about Shore A 35 to 75 and other times about Shore A 50 to 60, or Shore a 50 to 75.

Example II below illustrates a percent change in force per unit width of selected pre-strained dressings maintained at a constant strain for a period of time under testing conditions.

In this example, 10 dressing membranes were strained at 45%. The dressing membranes were constructed of polyurethane by 3M (St. Paul, Minn.). The samples were initially 8″ (+−0.02″) X 1″ (+−1″) with a thickness of 0.002″. The samples had a tensile strength of about 2.2 lbs/in, and elongation of about 300%. Six inch (6″) centered gage marks were added. The 45% strain samples' gage lengths increase to 8.7″ when strained. The samples were attached in a strained configuration to sample fixtures or clamps with a locking bar between the sample fixtures. Samples fixtures were constructed of Acrylic (PMMA) and coated with an anti-skid tape. When tested, the ends of the sample fixtures were attached to grips of a Tensile Tester Chatillon Model TCD225, 50 LBF load cell. Measurements were then taken after releasing the locking bar. The samples were stored in the test lab at ambient lab temperatures for the duration of the test. The tensile forces of the dressings were measured at various time intervals

FIG.9illustrates the percent loss of force over time for each of the dressings. An initial average post strain loss after one day at 45% strain was about 33%. Following the initial post strain loss, it was surprising that the additional loss after the initial loss decreased at a slower rate and was on average was about 12% for a period of 13 days (total of 45% loss average).

FIG.7is a schematic illustration of percent loss of force over time of a variation of an elastic material of a dressing strained a predetermined amount and held in a strained configuration over time. According toFIG.7, the dressing and/or dressing material is held at a constant strain for a period of time. The initial strain may be selected to provide for different percent force loss values at particular times. The percent force loss values and force values may vary for different initial strain levels and different materials. The curve plot for a particular dressing material may be determined for example as described with respect to Example I. As the percentage force loss increases, the force value decreases for a particular material or dressing, and/or the average force loss value for a lot of manufactured material or dressings, pre-strained substantially the same amount. At time T0, the material is strained. During an initial time frame of T0to T1, the percent force loss of the material occurs at a more rapid rate than it does in subsequent time periods or time frames, for example from T1to T3, from T1to T2, and/or from T2to T3. The time frames T1to T3, T1to T2, and/or T2to T3represent exemplary time frames that may or may not be selected based on desired force properties for a dressing, desired times for use of property, and/or desired rates of loss of force. For example, a dressing may be pre-strained at manufacture and then stored or transported for later use during a specified time frames, for example T1to T2, T2to T3and/or T1to T3.

FIG.8is a schematic illustration of force over time of a variation of an elastic material of a dressing strained a predetermined amount and held in a strained configuration over time. According toFIG.8, the dressing and/or dressing material is held at a constant strain for a period of time. The initial strain may be selected to provide for different force values at particular times. The force values and percent force value losses may vary for different initial strain levels and different materials. The curve plot for a particular dressing material may be determined for example as described with respect to Example I. As the percentage force loss increases, the force value decreases for a particular material or dressing, and/or the average force loss value for a lot of manufactured material or dressings, pre-strained substantially the same amount. At time T0, the material is strained. During an initial time frame of T0to TA, the material loses force at a more rapid rate than it does in subsequent time periods or time frames, for example from TA to TC from TA to TB and/or from TB to TC. The time frames T0to TA, TA to TB, and/or TB to TC represent exemplary time frames that may or may not be selected based on desired force properties for a dressing, desired times for use of property, and/or desired rates of loss of force. For example, a dressing may be pre-strained at manufacture and then stored or transported for later use during a specified time frames, for example TA to TB, TB to TC and/or TB to TC.

In another example, a method for modulating tissue response at a target site is provided, comprising providing a strained elastic structure with an access opening and a support structure, placing the strained elastic structure against a target site, releasing the strained elastic structure from the support structure, and inserting an access structure into the target site, wherein the access structure is located in the access opening. The strained elastic structure may be an elastic sheet with an adhesive layer. Attaching the strained elastic structure to the target site may comprise adhering the strained elastic structure to a skin location. The support structure may comprise at least one pull tab, and releasing the strained elastic structure from the support structure may comprise actuating the pull tab to release the strained elastic structure from the support structure. The method may further comprise inserting the access structure through the access opening. The access structure may be a delivery tube, and wherein the method may further comprise passing a sensor or infusion cannula using the delivery tube. The access structure may be attached to a housing. The housing may comprises a skin configured to attach the housing to a skin surface. The housing may further comprise a support layer, and the adhesive may be located on the inferior surface of the support layer. The method may further comprise adhering the housing to the elastic structure. The method may further comprise releasing the access structure from a delivery device after inserting the access structure into the target site. The method may further comprise aligning the delivery device with indicia or alignment structures located on the strained elastic structure.

In another embodiment, a tissue treatment device is provided, comprising a strained elastic layer comprising a top surface, a bottom surface and a treatment opening, a skin adhesive layer adhered to the bottom surface of the strained elastic layer, a protective layer releasably contacting the adhesive layer, a strain support removably attached to the top surface of the elastic layer, the strain support comprising a layer structure with a center opening surrounding the treatment opening of the strained elastic layer, the strain support having sufficient rigidity to maintain the strained elastic layer in a strained configuration, and at least one alignment structure located on the strain support and surrounding the center opening of the strain support. The strain support may further comprise a perforation region from the center opening to an edge of the strain support. The alignment structure may comprise a separation region aligned with the perforation region of the strain support. The strain support may comprise a first end, a second end, and an arcuate body therebetween defining the center opening of the strain support. The device may further comprise a strain support adhesive layer between the strained elastic layer and the strain support, wherein the strain support adhesive layer has a lower T-peel force than the skin adhesive layer. The strained elastic layer may be heat staked to the strain support. The strain support may further comprise perforations to facilitate separation of the strain support from the strained elastic layer.

In another embodiment, a multi-layer tissue treatment device is provided, comprising a strained elastic base layer comprising a top surface, a bottom surface, a perimeter edge and a treatment opening, a skin adhesive layer adhered to the bottom surface of the strained elastic layer, a protective layer releasably contacting the skin adhesive layer, at least one strained elastic intermediate layer, wherein each elastic intermediate layer comprises a top surface, a bottom surface, a perimeter edge and a treatment opening aligned with the treatment opening of the strained elastic base layer, and wherein the bottom layer of one of the at least one intermediate elastic layer is attached to a top surface of the strained elastic base layer, a strained elastic top layer, comprising a top surface, a bottom surface, a perimeter edge and a treatment opening, wherein the treatment opening of the strained elastic top layer is aligned with the treatment opening of the strained elastic base layer, and the bottom surface of the strained elastic top layer is attached to the top surface of one of the at least one intermediate elastic layer, and a strain support releasably attached to at least one of the strained elastic top layer, strained elastic bottom layer, and the at least one elastic intermediate layer, wherein the strain support is configured to maintain the strain of the elastic base layer, the at least one intermediate layer, and the elastic top layer. The perimeter edge of the elastic top layer may be offset from the perimeter edge of the intermediate elastic layer that is attached to the elastic top layer, and wherein the perimeter edge of the elastic intermediate layer that is attached to the elastic base layer may be offset from the perimeter edge of the elastic base layer. The perimeter edge of the elastic top layer may be offset inward from the perimeter edge of the intermediate elastic layer that is attached to the elastic top layer, and wherein the perimeter edge of the elastic intermediate layer that is attached to the elastic base layer may be offset inward from the perimeter edge of the elastic base layer. The device of claim8, wherein the bottom surface of the elastic top layer is smaller than the top surface of the intermediate elastic layer that is attached to the elastic top layer, and wherein the bottom surface of the elastic intermediate layer that is attached to the elastic base layer is smaller than the top surface of the elastic base layer. The bottom surface of the elastic top layer may be larger than the top surface of the intermediate elastic layer that is attached to the elastic top layer, and wherein the bottom surface of the elastic intermediate layer that may be attached to the elastic base layer is larger than the top surface of the elastic base layer. The device of claim8, the strained elastic top layer, the strained elastic base layer, and each of the at least one elastic intermediate layers, each has a different size. The elastic top layer may be smaller than all of the at least one elastic intermediate layers, and wherein all of the at least one elastic intermediate layers may be smaller than the elastic base layer. The elastic top layer may be larger than all of the at least one elastic intermediate layers, and wherein all of the at least one elastic intermediate layers may be larger than the elastic base layer. The at least one elastic intermediate layer may comprise two elastic intermediate layers. The at least one elastic intermediate layer may comprise two elastic intermediate layers. The strained elastic top layer and the at least one elastic intermediate layer may each comprise a pull tab.

The pull tab of the strained elastic top layer and the pull tab of the at least one elastic intermediate layer may each be a different size. The pull tab of the elastic top layer may be smaller than all of the pull tabs of the at least one elastic intermediate layers. The pull tab of the elastic top layer may be larger than all of the pull tabs of the at least one elastic intermediate layers. The strain support may be releasably attached to the top surface of the strained elastic top layer. The attachments of the top layer and the at least one intermediate layer may utilize anisotropic adhesive patterns. The anisotropic adhesive pattern may have a reduced amount of adhesive along a peel direction as compared to a strain direction of the strained layers.

In another embodiment, a multi-layer tissue treatment device is provided, comprising at least two strained elastic layers, comprising at least a top elastic layer and at least a base elastic layer, wherein each of the at least two strained elastic layers comprises a top surface, a bottom surface, a size, a perimeter edge and a treatment opening, and wherein the at least two strained elastic layers are releasably attached together in a stacked configuration, a skin adhesive layer adhered to the bottom surface of the base elastic layer, a strain support releasably attached to the base elastic layer, wherein the strain support is configured to maintain the strains of the at least two strained elastic layers. A force per width level in the base elastic layer may be higher than a force per width level of any other of the at least two strained elastic layers. The base elastic layer may comprise at least 70% of a total force per width in the at least two strained elastic layers. The base elastic layer may comprise at least 90% of the total force per width in the at least two strained elastic layers. The base elastic layer may comprise a higher durometer material or a greater thickness than the other at least two strained elastic layers. The at least two strained elastic layers may further comprise at least one intermediate elastic layer, located in the stacked configuration between the top elastic layer and the base elastic layer. The perimeter edge of each of the at least two strained elastic layers may be offset from the perimeter edge of an adjacent strained elastic layer in the stacked configuration. The perimeter edge of each of the at least two strained elastic layers may be offset inward from the perimeter edge of an adjacent higher strained elastic layer in the stacked configuration. The perimeter edge of each of the at least two strained elastic layers may be offset outward from the perimeter edge of an adjacent higher strained elastic layer in the stacked configuration. The perimeter edge of each of the at least two strained elastic layers may be offset inward from the perimeter edge of an adjacent lower strained elastic layer in the stacked configuration. The size of each of the at least two strained elastic layers may be different. The size of each of the at least two strained elastic layers may be smaller than any adjacent lower strained elastic layer in the stacked configuration. The size of each of the at least two strained elastic layers may be larger than an adjacent higher strained elastic layer in the stacked configuration. The size of each of the at least two strained elastic layers may be smaller than any adjacent higher strained elastic layer in the stacked configuration. The size of each of the at least two strained elastic layers may be larger than an adjacent lower strained elastic layer in the stacked configuration. The device of claim35, wherein at least one of the at least two strained elastic layers comprises a pull tab. Each pull tab of the at least one of at least two strained elastic layers may comprise a different pull tab size. The attachment of at least two strained elastic layers may utilize an anisotropic adhesive pattern. The attachments of the at least two strained elastic layers may comprises adhesive layers therebetween with a reduced amount of adhesive along an orthogonal direction to a strain direction of the strained layers. The orthogonal direction is a peel direction of the at least two strained elastic layers. The attachments of the at least two strained elastic layers may comprises a thinner adhesive layer than the skin adhesive layer of the strained base layer.

In still another embodiment, a treatment device is provided, comprising a strained elastic layer comprising an upper surface, a lower surface and an opening therebetween, a skin adhesive on the lower surface of the strained elastic layer, an infusion hub located on the upper surface of the strained elastic layer, with a catheter or needle extending through the opening of the strained elastic layer, fluid tubing attached to the infusion hub and in fluid communication with the catheter or needle, a strain support configured to maintain the strain in the strained elastic layer, and at least one pull tab configured to releasably attach the strained elastic layer and strain support together. The treatment device may further comprise an infusion set applicator that is releasably attached to the infusion hub. The device may further comprise two pull tabs located on opposite sides of the strained elastic layer. Each of the two pull tabs may comprise perforations configured to tear and so that the strained elastic layer and infusion hub can separate from the strain support.

In another example, a treatment device is provided, comprising a strained elastic layer comprising an upper surface, a lower surface and an opening therebetween, a skin adhesive on the lower surface of the strained elastic layer, an infusion hub located on the upper surface of the strained elastic layer, with a catheter or needle extending through the opening of the strained elastic layer, fluid tubing attached to the infusion hub and in fluid communication with the catheter or needle, a strain support configured to maintain the strain in the strained elastic layer, and at least one pull tab configured to releasably attach the strained elastic layer and strain support together. The treatment device may further comprise an infusion set applicator that is releasably attached to the infusion hub. The device may comprises two pull tabs located on opposite sides of the strained elastic layer. Each of the two pull tabs may comprise perforations configured to tear and so that the strained elastic layer and infusion hub can separate from the strain support.

In another example, a method for modulating tissue response at a target site is provided, comprising providing a strained elastic structure with an access opening and a support structure, placing the strained elastic structure against a target site, releasing the strained elastic structure from the support structure, and inserting an access structure into the target site, wherein the access structure is located in the access opening. The strained elastic structure may be an elastic sheet with an adhesive layer. Attaching the strained elastic structure to the target site may comprise adhering the strained elastic structure to a skin location. The support structure may comprise at least one pull tab, and releasing the strained elastic structure from the support structure may comprise actuating the pull tab to release the strained elastic structure from the support structure. The method may further comprise inserting the access structure through the access opening. The access structure may be a delivery tube, and wherein the method further comprises passing a sensor or infusion cannula using the delivery tube. The access structure is attached to a housing. The housing may comprise an adhesive. The housing may further comprise a support layer, and the adhesive is located on the inferior surface of the support layer. The method may further comprise adhering the housing to the elastic structure. The method may further comprise releasing the access structure from a delivery device after inserting the access structure into the target site. The method may further comprise aligning the delivery device with indicia or an alignment structure located on the strained elastic structure.

In another embodiment, a method of treating a therapeutic site is provided, comprising placing a first tensioning member at a first location next to a target site, wherein the first tensioning member is pre-tensioned along a first tensioning axis, placing a second tensioning member at a second location next to the target site, wherein the second tensioning member is pre-tensioned along a second tensioning axis and wherein the second location is spaced apart from the first location by a gap no greater than 20 mm and wherein the target site is located in the gap, and injecting or infusing a therapeutic agent at the target site. The first tensioning axis and the second tensioning axis may be parallel. The first tensioning member and the second tensioning member may be completely separate. The first and second tensioning members may be integrally formed with a predetermined longitudinal gap therebetween, the longitudinal gap comprising a longitudinal gap axis. The longitudinal gap axis may be located between the first and second tensioning axes. The longitudinal gap, the first tensioning axis and the second tensioning axis may each be parallel to each other. The predetermined longitudinal gap has an average of width of less than 20 mm, less than 10 mm, or less than 5 mm. The method may further comprise adhering an infusion set to the first and second tensioning members before using the infusion set to infuse the therapeutic agent.

In another embodiment, a method of treating lipodystrophy is provided, comprising applying an adhesive skin tensioning device to an injection or infusion site of a patient to reduce the risk of lipodystrophy. The injection or infusion site may be an insulin or insulin analogue injection or infusion site. The patient may be diabetic and the lipodystrophy may be lipohypertrophy. The patient may have no prior history of lipohypertrophy, or may have a prior history of lipohypertrophy. The method may further comprise reducing the risk of insulin resistance, and/or reducing the rate of insulin or insulin analogue dosage increase over a time period. The time period may be one year.

In another embodiment, a method of treating diabetes is provided, comprising applying an adhesive skin tensioning device to an injection or infusion site of diabetes patient to reduce the rate of insulin or insulin analog dosage increase over time.

In still another embodiment, a method of treating diabetes may be provided, comprising applying an adhesive skin tensioning device to an injection or infusion site of diabetes patient to improve glucose time-in-range. The glucose time-in-range may be a daily, weekly, or monthly glucose time-in-range.

In another example, a method of reducing diabetes treatment costs in a diabetic population may be provided, comprising applying an adhesive skin tensioning device to an insulin or insulin analogue injection or infusion site of diabetes patient to reduce the costs of blood glucose variability or serious adverse events.

In still another example, a method of treating a therapy site is provided, comprising adhering a multi-layer strained dressing to a treatment site, releasing the strain of the multi-layer strained dressing to transfer strain from the dressing to the treatment site to reduce tissue tension at the treatment site, attaching a first hub and a first catheter to the multi-layer dressing, delivering a therapeutic agent through the first hub and first catheter to the treatment site, removing the first hub and first catheter from the multi-layer dressing by removing a first layer from the multi-layer dressing, attaching a second hub and a second catheter to the multi-layer dressing, delivering the therapeutic agent through the second hub and second catheter to the treatment site, removing the second hub and second catheter from the multi-layer dressing by removing a second layer from the multi-layer dressing.

In another embodiment, a method of positioning an infusion set is provided, comprising adhering a strained skin tension off-loading device to a treatment location, wherein the skin tension off-loading device comprises a strained elastic layer with a treatment opening, a strain support and a protruding alignment structure surrounding the treatment opening, positioning an infusion set applicator over the treatment opening by using the alignment structure, actuating the infusion set applicator to decouple an infusion set hub from the infusion set applicator and to insert a catheter of the infusion set hub through the treatment opening, removing the infusion set applicator, and removing the strain support and protruding alignment structure from the strained skin tension off-loading device to release the strain in the strained elastic layer. The method may further comprise selecting the protruding alignment structure from a plurality of different protruding alignment structures and attaching the selected protruding alignment structure to the strain support. The protruding alignment structure may be integrally formed with the strain support.

According to some variations, the elastic device may be strained at different strain values during pre-conditioning.

DETAILED DESCRIPTION

Previous attempts to treat scars and keloids have included surgery, silicone dressings, steroids, x-ray irradiation, and cryotherapy. Each of these techniques has disadvantages. Perhaps the biggest disadvantage is that none of them effectively prevent or ameliorate the formation of scars or keloids in the first instance. That is, these techniques have primarily been used to treat scars after they are already well established.

Unloading of exogenous and/or endogenous stress in the vicinity of the wound may ameliorate the formation of scars, hypertrophic scars, or keloids. The mechanical environment of an injury may be an important factor in tissue response to that injury. The mechanical environment includes exogenous stress (i.e., physiological stress which includes stress transferred to the wound via muscle action or physical body movement) and endogenous stress (i.e., dermal stress originating from the physical properties of the skin itself, including stress induced at the wound site due to swelling or contraction of the skin). The devices, dressings, kits and methods described herein may control or regulate the mechanical environment of a skin including but not limited to the mechanical environment of a wound. The devices, dressings, kits and methods described herein may also control or regulate the mechanical environment to ameliorate scar and/or keloid formation. The mechanical environment of skin may include stress, strain, or any combination of stress and strain. The control of a wound's mechanical environment may be active or passive, dynamic (e.g., by applying an oscillating stress) or static. The stresses and strains acting on the wound may involve the layers of the skin, such as the outer stratum corneum, the epidermis and dermis, as well as the underlying connective tissue layers, such as the subcutaneous fat. Devices and methods described here may shield a wound from its mechanical environment. The term “shield” is meant to encompass the unloading of stress experienced by the wound as well as providing a physical barrier against contact, contaminants, and the like. The devices and methods described here may shield a wound by unloading the wound and surrounding tissues from endogenous stress and/or exogenous stress. Thus, devices and methods described here may reduce the stress experienced by a wound and surrounding tissues to a lower level than that experienced by normal skin and tissue. Unloading of exogenous and/or endogenous stress in the vicinity of the wound may ameliorate the formation of scars, hypertrophic scars, or keloids.

A cell's external mechanical environment may trigger biological responses inside the cells and change cell behavior. Cells can sense and respond to changes in their mechanical environment using integrin, an integral membrane protein in the plasma membrane of cells, and intracellular pathways. The intracellular pathways are initiated by receptors attached to cell membranes and the cell membrane that can sense mechanical forces. For example, mechanical forces can induce secretion of cytokines, chemokines, growth factors, and other biologically active compounds that can increase or trigger the inflammatory response. Such secretions can act in the cells that secrete them (intracrine), on the cells that secrete them (autocrine), on cells surrounding the cells that secrete them (paracrine), or act at a distance from the point of secretion (endocrine). Intracrine interference can alter cell signaling, which can in turn alter cell behavior and biology including the recruitment of cells to the wound, proliferation of cells at the wound, and cell death in the wound. In addition, the extracellular matrix may be affected.

As noted above, the wound healing process may be characterized in three stages: early inflammatory phase, the proliferative phase, and remodeling. The inflammatory phase occurs immediately after injury and typically lasts about two days to one week. Blood dotting takes place to halt blood loss and factors are released to attract cells that can remove debris, bacteria and damaged tissue from the wound. In addition, factors are released to initiate the proliferative phase of wound healing. In the proliferative phase, which lasts about four days to several weeks, fibroblasts grow and build a new extracellular matrix by secreting collagen and proteoglycans. At the end of the proliferative phase, fibroblasts can act to contract the wound further. In the remodeling phase, randomly oriented collagen is organized and crosslinked along skin tension lines. Cells that are no longer needed can undergo apoptosis. The remodeling phase may continue for many weeks or months, or indefinitely after injury. Scars typically reach about 75-80% of normal skin breaking strength about 6-8 weeks after injury. In general, scars typically have a triangular cross-section. That is, a scar is usually smallest in volume near the skin surface (i.e., stratum corneum and epidermis) and increases in volume as it progresses into the deeper layers of the dermis.

There are three common possible outcomes to a wound healing process. First, a normal scar can result. Second, a pathologic increase in scar formation can result, such as formation of a hypertrophic scar or a keloid. Third, the wound may not heal completely and become a chronic wound or ulcer. The devices, kits and methods described herein can ameliorate the formation of any type of scar. In addition, the devices, kits and methods described here can be adapted for a variety of wound sizes, and for different thicknesses of skin, e.g., the devices may be configured for use in different areas of the body. In addition, the devices, kits and methods described here can be adapted to ameliorate scar formation in any type of skin, e.g., body location, age, race, or condition.

Without wishing to be bound by any particular theory, we believe that mechanical strain acting on a wound or incision early in the proliferative phase of the wound healing process may inhibit cellular apoptosis, leading to a significant accumulation of cells and matrix, and hence increased scarring or the production of hypertrophic scars. Given the underlying similarities between hypertrophic scars and keloids with respect to excessive matrix formation, we believe that the devices and methods described herein may also be useful in preventing and treating keloids by offloading or neutralizing at least some of the strain that may be acting on the wound or incision. This tensile strain may be exogenous and/or endogenous strain, and may include but is not limited to the strain from the intrinsic tensile forces found in normal intact skin tissue.

A number of wound dressings have backings, adhesive liners and/or packaging that are removed prior to application of a wound dressing. Many existing dressings can be clumsy to orient and apply and can have a tendency to fold and adhere to themselves.

Devices, kits and methods described herein may treat skin at a skin site (“skin treatment device”), including without limitation, to ameliorate the formation of scars at wound sites by controllably stressing or straining the epidermis and deeper layers of dermal tissue at or near a skin site, i.e., at or adjacent a wound or treatment site of a subject's skin, thereby reducing tensile or compressive stress at the skin site. The stress at the skin site may be reduced to levels below that experienced by normal skin and tissue. The stress or strain may be applied to surrounding tissue in one, two, or more directions to reduce endogenous or exogenous stress at the skin site in one, two or more directions. Thus, devices and methods described herein may reduce the stress experienced by skin and/or a wound and surrounding tissues in order to treat a subject. The device may also assist in preventing or reducing the incidence of wound dehiscence.

Devices, kits and methods described herein may provide a packaging and/or applicator for a dressing. According to one variation, the packaging and/or applicator is configured to provide quick or easy preparation and/or application of a dressing. While some examples herein specifically refer to a packaging that also acts as a tensioning device to pre-strain a dressing, other dressings that are not pre-strained and/or strained prior to application may be provided in accordance with one or more variations or embodiments. The packaging may also operate as an applicator where one or more elements of the packaging may be used to position and/or apply the dressing to the skin of a subject.

Devices kits and methods described herein may be for the preparation and/or application of a dressing. Such preparation may include but is not limited to, for example, removal of an adhesive liner, straining or tensioning a dressing, orienting a dressing for application and/or applying a medicament or other material to a portion of the dressing prior to application.

Backings, adhesive liners or release layers, and/or other packaging may provide some structural stability to a flexible wound dressing. However, when removed, the flexible wound dressing can be somewhat clumsy to use because it may fold and adhere to itself or the user, or otherwise provide for difficult positioning over the wound. Also the act of pulling or removing the liner and reorienting the dressing to the patient may increase the tendency to fold or flop. Furthermore, because of the folding or floppiness of the dressing, during adhesive removal and subsequent reorientation, the user has a significant possibility of compromising the sterility of a portion of the device to be applied to a wound site.

According to another variation, a packaging or applicator is configured to provide support for the dressing after the dressing is prepared and while the dressing is applied to a subject. According to some variations, a backing provides structural support or stability of the dressing as and/or after an adhesive liner is released. According to some variations, a dressing and packaging is configured to be pre-oriented in a position facing a wound .i.e., for immediate application when and after the wound device is prepared for application. According to some variations, the packaging applicator is configured to be used with one hand to orient and/or apply the device to the skin of a subject.

According to some variations, the packaging dressing carrier, support, base tensioning device or applicator tensioning device and/or applicator provide a release mechanism to separate the applied dressing from the packaging and/or applicator after the dressing is applied to the skin. According to a variation, a dressing may be prestrained and coupled to a dressing carrier, support, base tensioning device or applicator, for example as set forth in U.S. Provisional Application Ser. No. 61/512,340 filed on Jul. 17, 2011 and incorporated in its entirety herein by reference. One or more dressing releases described herein may be used with a dressing carrier, support, base tensioning device or applicator.

In some further variations, the dressing or one or more adhesive regions of the dressing may be released, i.e., separated, from the liner by opening a packaging or applicator. According to some variations, a book-like packaging is provided with a cover, and a base to which a dressing is removably attached. When or as the cover is opened, the liner may be manually or automatically released from the adhesive of the dressing. According to variations, a liner is attached to the cover and will expose an adhesive side of a dressing when the cover is lifted or opened. The base may be configured to provide structural support to the dressing while the liner is removed and/or while the dressing is applied to the skin of a subject.

According to some variations, the packaging, tensioning device, dressing carrier, support, base or applicator may further comprise an opening, a window, or a clear or semi-opaque portion through which a wound, incision or other location may be visualized as the dressing is applied to the skin. According to some variations, the window guides the application of a dressing so that there is an optimal or desired distance between the wound and the edges of the dressing and/or so that the dressing is in an optimal location for unloading skin stresses.

According to some variations the applicator, tensioning device, packaging or carrier, support, or base may provide varied or variable flexibility to allow the dressing to be shaped when applied to various body locations or contours.

According to some variations, a packaging or applicator is more rigid or provides sufficient column strength in at least a first direction to be supportive of a dressing, while being relatively more flexible and less rigid in at least second direction to provide for a more conforming application to a curved or shaped skin surface of a subject or to permit curvature or shaping of the dressing where it is applied. The first and second directions may or may not be orthogonal to each other. According to some variations, a packaging applicator, tensioning device or dressing carrier, support or base is sufficiently rigid or supportive of a dressing while permitting shaping of the dressing, According to some variations, the carrier or support which may include a base and/or a cover may comprise segments of relatively more rigid material flexibly coupled to adjacent segments to provide flexibility to permit shaping of packaging/applicator and/or dressing while providing sufficient support of the dressing during application. According to some variations, segments are coupled to adjacent segments by way of a flexible material, such as a low-density polyethylene (LDPE) material, or a composite of adhesive and a thinner more flexible substrate. Alternatively, segments may be formed as a structure by manufacturing a substrate with cut-outs, slots, grooves, scoring or other openings or variations in thickness of the substrate at different locations.

The packaging, applicator, tensioning device, or dressing carrier may have elements or features the provide flexibility in one direction orthogonal to the plane of the support while limiting flexibility in another direction orthogonal to the plane of the support. According to some variations, the flexible elements may limit flexibility when the device is being strained and permit flexibility when the device is being applied to the skin. Each of the elements may permit flexing in a different direction than one or more of the other elements. Flexible elements may be straight, or shaped according to a desired application or location of placement.

According to variations, flexible elements are provided in combination with support elements that provide sufficient support to allow a user to maintain the dressing in a strained configuration. According to variations, one or more elements may be provided to maintain a strained dressing in a strained configuration, for example a securing element that secures the dressing in a strained configuration until it is applied to a subject and is released from the carrier, support, base tensioning device or applicator. For example, after straining the dressing, the dressing may be adhered or attached to one or more elements of a dressing, support, base tensioning device or applicator or dressing assembly until it is released from the carrier, support, base tensioning device or applicator or assembly.

According to some variations, the applicator may be further used to help reduce bleeding, e.g., by allowing application of a compressive force using a support structure while or after the device is applied. One or more hemostatic or coagulative agents may be applied to, or otherwise integrated with dressing to help reduce bleeding. Potential agents include chitosan, calcium-loaded zeolite, microfibrillar collagen, cellulose, anhydrous aluminum sulfate, silver nitrate, potassium alum, titanium oxide, fibrinogen, epinephrine, calcium alginate, poly-N-acetyl glucosamine, thrombin, coagulation factor(s) (e.g. II, VII, VII, X, XIII, Von Willebrand factor), procoagulants (e.g. propyl gallate), antifibrinolytics (e.g. epsilon aminocaproic acid), and the like. In some variations, the agents may be freeze-dried and integrated into the dressing and activated upon contact with blood or other fluid. In some further variations, an activating agent may be applied to the dressing or the treatment site before the dressing is used on the subject. In still other examples, the hemostatic agent may be applied separately and directly to the wound before application of the dressing, or after application to the dressing via a catheter or tube. The devices may also comprise one or more other active agents that may be useful in aiding in some aspect of the wound healing process. For example, the active agent may be a pharmaceutical compound, a protein (e.g., a growth factor), a vitamin (e.g., vitamin E), or combinations thereof. A further example of such medicament may include, but is not limited to various antibiotics (including but not limited to cephalosporins, bactitracin, polyxyxin B sulfate, neomycin, polysporin), antiseptics (such as iodine solutions, silver sulfadiazine, chlorhexidine), antifungals (such as nystatin), antiproliferative agents (sirolimus, tacrolimus, zotarolimus, biolimus, paclitaxel), grow factors (such as VEGF) and other treatments (e.g. botulism toxin. Of course, the devices may comprise more than one medicament or agent, and the devices may deliver one or more medicaments or agents.

According to one variation, the applicator and or packaging may be sufficiently supportive or rigid to hold a dressing's form so that it is easy to manipulate. According to a variation, the applicator may be sufficiently wider and/or longer or have a sufficiently larger area than a dressing so that it may provide sterile application and/or one-handed application. According to variations, a support structure is provided for a dressing. According to a variation, a margin is provided as a support structure between the dressing or dressing adhesive and one or more edge portions of the support structure. Such margins provide a supported edge or area to grasp or manipulate the dressing or its carrier, base or support, without necessitating or creating a greater likelihood of inadvertent user contact with the adhesive.

According to some variations, the packaging or applicator may also be used to strain a dressing prior to application to provide a dressing configured to ameliorate scar or keloid formation.

Devices are described here that may be used for ameliorating the formation of scars and/or keloids at a skin or wound site. The scars may be any type of scar, e.g., a normal scar, a hypertrophic scar, etc. In general, the devices may be configured to be removably secured to a skin surface near a wound. The devices may shield the skin or wound from endogenous stress and/or exogenous stress. In some variations, the devices may shield the skin or wound from endogenous stress without affecting exogenous stress on the skin or wound, e.g., devices that modify the elastic properties of the skin, etc. In other variations, the devices may shield the skin or wound from exogenous stress without affecting endogenous stress on the wound. Such variations may include situations where the musculature and surrounding skin or wound tissue has been paralyzed, e.g., through the use of botulinum toxin or the like. In still other variations, the devices shield the skin or wound from both endogenous and exogenous stress.

The devices or dressings described herein may treat skin at a skin site including without limitation to ameliorate the formation of scars at wound sites by controllably stressing or straining the epidermis and deeper layers of dermal tissue at or near a skin site, thereby reducing tensile or compressive stress at the skin site itself. The stress at the skin site may be reduced to levels below that experienced by normal skin and tissue. The stress or strain may be applied to surrounding tissue in one, two, or three directions to reduce endogenous or exogenous stress at the skin site in one, two or three directions. The physical characteristics of the dressing and/or the method of applying the dressing may also be further configured to resist or reduce the rate of skin stripping or tension blistering from the application of strain to the incision site. For example, the stretching of the adhesive regions when applied to the skin surface may result in an increased tissue density under the adhesive region. This may be the result of generally planar, tangential or parallel compression of skin tissue that is directly attached to that adhesive region, resulting from the relaxation of the adhesive region. In some examples, this tissue compression may reduce the risk of tissue stripping and/or blistering of skin in direct contact with the adhesive, in contrast to bandage “strapping” where one end of a bandage is adhered to the skin and then tensioned or pulled across a wound before the other end is attached to the skin on the opposite side of the wound. Bandage “strapping”, while generating tension in the bandage during the application, may simultaneously generate a relatively high tissue strain at the first adhesion site. This high tissue strain then decreases when the bandage is attached to the skin at a second adhesion site as the high peak stresses are redistributed along the skin under the bandage. In contrast, when a pre-strained bandage is applied to the skin, little if any strain may be transferred or generated in the skin as the adhesive regions are applied to the desired locations. When the pre-strained bandage is permitted to relax, however, the strain (or peak strain) in the skin may be increased. Thus, with a pre-strained bandage, temporary high tissue strain may be avoided or otherwise reduced during the application procedure. In other variations, however, the dressing may also be applied to the skin by strapping, or by a combination of pre-straining and strapping.

The dressing may comprise an elastic member, such as a sheet of elastic material. The elastic material of the dressing may comprise a single layer of material or multiple layers of the same or different materials. The material may have any of a variety of configurations, including a solid, foam, lattice, or woven configuration. The elastic material may be a biocompatible polymer, e.g., silicone, polyurethane, TPE (thermoplastic elastomers), synthetic rubber or co-polyester material. The thickness of polymer sheets may be selected to provide the dressings with sufficient load carrying capacity to achieve desired recoverable strains, and to prevent undesired amounts of creep deformation of the dressings over time. In some variations, the thickness across dressings is not uniform, e.g., the thickness across the dressing may be varied to change the stiffness, the load carrying capacity, or recovery strains in selected orientations and/or locations. The elastic material of the exemplary dressing may have a thickness in the range of about 50 microns to 1 mm or more, about 100 microns to about 500 microns, about 120 microns to about 300 microns, or in some variations about 200 microns to about 260 microns. The exemplary dressings have an edge thickness of about 500 microns or less, 400 microns or less, or about 300 microns or less may exhibit less risk of skin separation from inadvertent lifting when inadvertently brushed against clothing or objects. In some variations, the dressings are tapered near the edges to reduce thickness. A tapered edge may also ameliorate peak tensile forces acting on skin tissue adjacent to the adhesive edges of the dressing. This may or may not reduce the risk of skin blistering or other tension-related skin trauma. In other variations, the edges of the dressing may be thicker than the middle of the dressing. It is hypothesized that in some configurations, a thicker dressing edge may provide a relative inward shift of the location of the peak tensile forces acting near the dressing edge, compared to dressings of uniform thickness. The elastic material may have a load per width of at least 0.35 Newtons per mm at an engineering strain of 60% or a load per width of at least 0.25 Newtons per mm at an engineering strain of 45%. The elastic material may have a load per width of no greater than about 2 Newtons per mm at the engineering strain of about 45% to 60%, about 1 Newtons per mm at the engineering strain of about 45% to 60%, about 0.7 Newtons per mm at the engineering strain of about 45% to 60%, or no greater than about 0.5 Newtons per mm at the engineering strain of about 45% to 60%. The system elastic material may have a load per width that does not decrease from an engineering strain of 0% to 60%, a load per width plot that increases linearly from an engineering strain of 0% to 60%, or a load per width plot that is not convex from an engineering strain of 0% to 60%. The elastic material may comprise an adhesive configured to maintain a substantially constant stress in the range of 200 kPa to about 500 kPa for at least 8 hours when strained to an engineering strain of about 20% to 30% and attached to a surface. The elastic material may comprise an adhesive configured to maintain a substantially constant stress in the range of 200 kPa to about 400 kPa for at least 8 hours when strained to an engineering strain of about 20% to 30% and attached to a surface. The substantially constant stress may vary by less than 10% over at least 8 hours, or by less than 5% over at least 8 hours.

Although the depicted dressings may have a generally rectangular configuration with a length and/or width of about 160 mm to about 60 mm, in other variations the dressing may have any of a variety of lengths and widths, and may comprise any of a variety of other shapes. Also, the corners of the dressing may be squared or rounded, for example. The lengths and/or widths of an exemplary dressing may be in the range of about 5 mm to about 1 meter or more, in some variations about 20 mm to about 500 mm, and in other variations about 30 mm to about 50 mm, and in still other variations about 50 mm to about 100 mm. In some variations, the ratio of the maximum dimension of the dressing (e.g. its length) to an orthogonal dimension to the maximum dimension (e.g. width), excluding the minimum dimension of the dressing (e.g. the thickness), may be in the range of about 1:3, about 1:2, about 1:1, about 2:1, about 3:1, about 4:1 about 5:1, about 6:1, about 7:1, about 8:1, about 9:1 or about 10:1 or greater. In some variations, the strain axis of the dressing in use may be oriented with respect to the maximum dimension or to the orthogonal dimension to the maximum dimension. In some variations, the final compressive stress and strain imposed onto the skin by the elastic material may be the result of the dynamic equilibrium between the tensile stress in the skin and the elastic material of the dressing. The skin at the skin site typically comprises an inherent tension that stretches incision site, whether or not any tissue was excised from the skin site. The elastic material and the adhesive region may be configured to be applied to a skin location so that when the dressing is stretched to a particular tension and then adhered to the incision site, tensile stress in the dressing is transferred to the incision site to compress the tissue directly under the dressing along a tangential axis to the skin surface, the stress and strain imposed onto the skin location has a net or resultant orientation or axis is also generally tangential or planar to the elastic material and/or the outer surface of the skin location, with a similar axis to the orientation or axis of the tensile stress in the dressing. The tension in the dressing will relax to a tension level that maintains equilibrium with increased tension in the skin adjacent to the dressing. The application of the dressing to the skin location may involve the placement of the dressing without overlapping or being wrapped onto itself, e.g. wherein only adjacent regions of the dressing are interconnected and wherein non-adjacent regions of the dressing are not interconnected. The actual amount of stress and strain imposed on the skin may vary, depending upon the particular person, skin location, the thickness or various mechanical characteristics of the skin layers (e.g. epidermis, dermis, or underlying connective tissues), and/or the degree of pre-existing scarring, for example. In some further variations, the wound treatment dressing may be selected or configured for use at a specific body location, such as the scalp, forehead, cheek, neck, upper back, lower back, abdominal region, upper torso (including but not limited to the breast folds), shoulder, upper arm, lower arm, palm regions, the dorsum of the hand, finger, thigh, lower leg, the dorsum or plantar surface of the foot, and/or toe. Where applicable, some body regions may be further delineated into anterior, posterior, medial, lateral, proximal and/or distal regions, e.g. the arms and legs.

The dressing may be configured to impose a skin strain in the range of about 10% to about 60% or more, in other configurations about 15% to about 50%, and in still other configurations, about 20% to about 30% or about 40%. To achieve the desired degree of skin strain, the dressing may be configured to undergo elastic tensile strain in the range of about 20% to about 80% or more, sometimes about 30% to about 60%, and other times about 40% to about 50% or about 60%. The dressing may comprise any of a variety of elastic materials, including but not limited to silicones, styrenic block copolymers, natural rubbers, fluoroelastomers, perfluoroelastomers, polyether block amides, thermoplastic elastomers, thermoplastic polyurethane, polyisoprene, polybutadiene, and the like. The material of the exemplary dressing may have a Shore A durometer in the range of about 20 to about 90, about 30 to about 80, about 50 to about 80. The exemplary dressing was constructed of MED 82-5010-05 by NUSIL TECHNOLOGY LLC (Carpinteria, Calif.). Other examples of suitable materials are described in U.S. application Ser. No. 11/888,978, which was previously incorporated by reference in its entirety.

When the dressing is applied to a skin location and allowed to at least partially recover to its base configuration, the recovery level or equilibrium level of strain in the dressing may be in the range of about 4% to about 60% or more, in other configurations about 15% to about 50%, and in still other configurations, about 20% to about 30% or about 40%. The ratio between the initial engineering tensile strain placed onto the dressing before recovery and the resulting engineering compressive strain in the skin may vary depending upon the skin type and location, but in some examples, may be about 2:1. In other examples, the ratio may be in the range of about 4:1 to about 5:4, about 3:1 to about 5:3, or about 5:2 to about 2:1. These skin strain characteristics may be determined with respect to a reference position of the body or body part, e.g. anatomical position, to facilitate reproducible measurements. The particular degree of strain may be characterized as either an engineering strain or a true strain, but may or may not be calculated based upon or converted from the other type of strain (e.g. the strain may be based upon a 45% engineering strain that is converted to a true strain).

In some further variations, one or more characteristics of the elastic material may correspond to various features on the stress/strain curve of the material. For example, the engineering and true stress/strain curves for one specific example of the dressing comprises a material that exhibits an engineering stress of about 1.2 MPa at about 60% engineering strain, but in other examples, the engineering stress may be in the range of about 900 KPa to about 3.5MPa, about 1 MPa to about 2.2 MPa, about 1 MPa to about 2 MPa, about 1.1 MPa to about 1.8 MPa, about 1.1 MPa to about 1.5 MPa, about 1.2 MPa to about 1.4 MPa. When unloading or relieving stress from the dressing, the material may be configured with an engineering stress of about 380 KPa at about 40% engineering strain, but in other examples, the engineering stress during unloading of the material to about a 40% strain may be in the range of about 300 KPa to about 700 KPa, about 325 KPa to about 600 KPa, about 350 KPa to about 500 KPa, or about 375 KPA to about 425 KPa. When unloading the material to an engineering strain of about 30%, the material exhibits an engineering stress of about 300 KPa, but in other examples, the engineering stress when unloading the material to about 30% strain may be in the range of about 250 KPa to about 500 KPa, about 275 KPa to about 450 KPa, about 300 KPa to about 400 KPa, or about 325 KPA to about 375 KPa. When unloading to an engineering strain of about 20%, the material may have an engineering stress of about 100 KPa, but in other examples, the unloading engineering stress at about 20% may be in the range of about 50 KPa to about 200 KPa, about 75 KPa to about 150 KPa, or about 100 KPa to about 125 KPa. In some examples, the material may be configured to at least achieve a specific range or level of engineering stress at each of the specified engineering strain levels described above, but in other examples, the material may be configured for lower levels of maximum engineering strain, e.g. up to about 30% or about 40%.

In some examples, certain portions of the stress/strain curve may have a particular morphology. For example, for a particular level of maximum strain the loading curve may be generally linear on the corresponding true stress/strain curve. In an example using a dressing described herein, up to a true strain of about 45%, the loading curve had a generally linear configuration. In other examples, the configuration may only be linear along a portion of the loading curve or may be curved along the entire loading curve. Where the loading curve is non-linear, the loading curve may be convex, concave or both. Also, in some examples, the tangent line of the loading curve (i.e. the line between the two triangles) may also be generally co-linear.

In some variations, the elastic material comprises a material having an elastic modulus E of at least about 1 MPa, about 1.5 MPa, about 2 MPa, about 2.5 MPa, about 3 MPa, about 3.5 MPa, about 4 MPa, about 5 MPa, about 6 MPa, about 7 MPa, about 8 MPa, about 9 MPa or at least about 10 MPa or greater. The material elastic modulus E may be no greater than about 10 MPa, about 9 MPa, about 8 MPA, about 7 MPa, about 6 MPa, or about 5 MPa, or about 4 MPa.

In addition to the absolute stress levels at certain strain levels described above, the material may also be characterized with respect to the ratio between a) the stress to achieve a particular strain during loading, and b) the stress at the same strain during unloading. For example, the material may have a ratio of at least 4:1 to about 3:2 at each of the 20%, 30% and 40% strain levels, but in other examples, the material may exhibit these ratios only at 20%, at 30%, or at 40% strain levels, or at both 20% and 30% but not 40%, or at both 30% and 40% but not 20%. In other examples, the ratio at one, some or all of the strain levels may be in the range of about 3:1 to about 2:1, or about 5:2 to about 2:1.

In some examples, the elastic material of the dressing may be configured under testing conditions to achieve a stable level of stress at a constant strain, e.g. the material exhibits a limited amount of stress relaxation over a particular period of time and at a particular level of strain. The period of time may be at least about 8 hours, about 12 hours, about 18 hours, about 24 hours, about 36 hours, about 48 hours, about 72 hours, about 4 days, about 5 days, about 6 days, or about a week or more. The level of strain may be about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, or about 80% or more. The stress of the exemplary dressing over various time curves may be configured to maintain an engineering stress of about 300 KPa at an engineering strain of about 30% without noticeable deviation over a period of about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, or about 8 hours or more. The stresses at 10% strain, 20% strain, and at 40% may be lower or higher.

In some variations, the elastic material or the dressing may be configured under testing conditions to maintain a particular minimum level of stress when held at a constant strain over a particular time period. In an example to assess the ability of a backing material to maintain a stress and strain on skin over time, engineering strains were measured while each backing material was tensile strained to 60% at a rate of 100 microns per second and held for 10 minutes, and then dropped to a strain of 30% at a rate of 100 microns per second and held for 9 hours. For example, the exemplary dressing is able to maintain an engineering stress level of about 350 KPa at an engineering strain of 30%. In some other examples, the minimum level of stress may be about 100 KPa, about 120 KPa, about 140 KPa, about 160 KPa, about 180 KPa, about 200 KPa, about 220 KPa, about 240 KPa, about 260 KPa, about 280 KPa, about 300 KPa, about 320 KPa, about 340 KPa, about 360 KPa, about 380 KPa, about 400 KPa, about 420 KPa, about 440 KPa, about 460 KPa, about 480 KPa, about 500 KPa, about 600 KPa, about 700 KPa, about 800 KPa, about 900 KPa or about 1000 KPa or greater. The level of constant strain may be different in other configuration, with a level of about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80%. The time period over which the dressing is able to maintain a stress level may be at least about 2000 seconds, about 3000 seconds, about 4000 seconds, about 5000 seconds, about 6000 seconds, about 7000 seconds, about 8000 seconds, about 9000 seconds, about 10000 seconds, about 20000 seconds, about 30000 seconds, about 40000 seconds, about 50000 seconds, about 60000 seconds, about 70000 seconds, about 24 hours, about 36 hours, about 48 hours, about 72 hours, about 4 days, about 5 days, about 6 days, about 7 days, about 10 days, about 2 weeks, about 1 month or more. In some variations, the dressing, the elastic material and/or the adhesive material is configured to exhibit less than about a 15% change in stress or strain level over the particular period when applied to a skin surface or test surface. In other examples, the degree of change may be about 12%, about 10%, about 8%, about 6%, about 5%, about 4%, about 3%, or about 2% or less. The stress or strain may be an engineering stress or strain, and/or a true stress or strain.

The adhesive used may be, for example, a pressure activated adhesive (PSA), as a silicone, acrylic, styrene block copolymer, vinyl ether, nitrile or other PSA. In other variations, a non-pressure sensitive adhesive may be used, including but not limited a heat or light-cured adhesive. The pressure sensitive adhesive may be made from, e.g., polyacrylate-based, polyisobutylene-based, silicone-based pressure sensitive adhesives, synthetic rubber, acrylic, and polyisobutylene (PIB), hydrocolloid, and the like. The T-peel release force and blunt probe tack force of the adhesive may be measured by a standardized test method, such as ASTM D1876 and ASTMD2979 or other appropriate method. In some variations, the T-peel release force or blunt probe tack test value of the adhesive is configured to maintain loads of at least about 50 mPa/mm for at least about 24 hours, about 48 hours, about 72 hours, about 1 week, about 2 weeks, about 3 weeks, about 4 weeks or more. In other variations, the loads may be at least about 75 mPa/mm, about 100 mPa/mm, about 125 mPa/mm, or at least about 150 mPa/mm over the particular time period. The degree of adhesion (e.g. as measured by the T-peel release force or blunt probe tack test value) may vary depending upon the degree of strain placed onto the skin or incision site, and in some variations, these time periods may be based upon an average skin strain of about 10%, about 20%, about 30%, about 40%, or about 50% or more. In some variations, the adhesive may have a T-peel release force of at least about 150 kg/m, about 160 kg/m , about 170 kg/m , about 180 kg/m, about 190 kg/m, about 200 kg/m, about 210 kg/m, about 220 kg/m, about 230 kg/m, about 240 kg/m, about 250 kg/m, about 260 kg/m, about 270 kg/m, about 280 kg/m, about 290 kg/m, about 300 kg/m, about 310 kg/m, about 320 kg/m, about 330 kg/m, about 340 kg/m, about 350 kg/m, about 400 kg/m, about 450 kg/m, or at least about 500 kg/m or higher. In some further variations, the T-peel release force may be no greater than about 1000 kg/m, about 900 kg/m, about 800 kg/m, about 700 kg/m, about 600 kg/m, about 500 kg/m, about 400 kg/m or about 300 kg/m. The blunt probe tack test value of the adhesive may be at least about 0.50 kg, about 0.55 kg, about 0.60 kg, about 0.65 kg, about 0.70 kg or about 0.75 kg or higher, and may be no greater than about 1 kg, about 0.9 kg, about 0.8 kg, about 0.7 kg, or about 0.6 kg. The T-peel release force and blunt probe tack force may be measured by a standardized test method, such as ASTM D1876 and ASTMD2979 or other appropriate method. Other features or variations of the device are described in U.S. application Ser. No. 11/888,978, filed on Aug. 3, 2007, incorporated in its entirety herein by reference.

The release liners may comprise any of a variety of materials, including both opaque and transparent materials. The release liners may comprise Mylar or paper, or any other material with reduced adhesion to the adhesive material(s) of the device. For example, for a silicone adhesive, a fluoropolymer-treated polyester film may be used, and for an acrylic pressure sensitive adhesive, a silicone treated polyester or Mylar film or silicone treated craft paper may be used. In variations where the device has multiple separate adhesive regions, separate release liners may be provided for each region, or some regions may be covered by the same release liner.

Examples of dressings, applicators or tensioning devices that may be used in the devices kits or methods herein may include those provided in U.S. application Ser. No. 12/854,859 filed Aug. 11, 2010, the disclosure of which is already incorporated in its entirety herein by reference without limitation.

The packaging assembly, applicator and/or tensioning device may comprise a tensioning structure, and a first attachment portion configured to releasably attach to a dressing and a second attachment portion configured to releasably attach to the dressing, wherein the tensioning structure may be configured to exert a separation force between the first attachment portion and the second attachment portion to cause a strain in a dressing attached to the first and second attachment portions. An elastic dressing may be configured to releasably attach to the first and second attachment portions of a dressing and packaging assembly and may include an attachment structure or may be integral with attachment structures of a packaging device, applicator or tensioning member. The tensioning structure may also act as an applicator device or may be configured to permit a user to apply a dressing to skin of a subject.

Attachment structures of a packaging device, dressing assembly, dressing carrier, support, base, applicator, tensioning or straining device may include any structures that are used to attach or couple an applicator, tension or straining device to a dressing. A dressing may or may not have attachment features or structures. Any such attachment features may be integral with or include any of the attachment structures or corresponding structures to the attachment structures of the packaging, applicator dressing and/or tensioning device.

In some variations the assembly may comprise one or more mechanisms or elements configured to facilitate separation, release, removal or detachment of the dressing from the packaging, applicator or tensioning device, other attachment elements or other portions of the dressing assembly, including but not limited to the separation devices and methods described herein. Release elements or releasable attachment structures may include but are not limited to pockets and tabs, hook and loop mechanism, hooks, angled bars, pivoting, rolling, rocking or sliding features associated with or coupled to attachment structures , adhesives, removable adhesives, adhesive tapes or other adhesive devices, pegs, rip cords, towel bar configurations, sliding pins, friction locks, cam locks, vacuum or suction devices, snap connectors, carpet tack, press fit connections or other connections, levers, latches, locking members, spring members, for example, or other mechanisms such as cutters or rip cords or other structures or features to facilitate tearing, cutting or separation of attachment structures or elements perforated or otherwise severable structures, that permit removal of dressing from the applicator ,packaging, other portions of the dressing assembly and/or attachment structures, features, elements or portions They may be self-releasing latches or spring members. They may be actuated when a pressure member is applied to a skin treatment device prior to removing the applicator. They may be manually actuated.

As noted, a packaging or applicator, tensioning device and/or straining device may be provided in some embodiments to impart a strain to a skin treatment device with an external force and/or to maintain a strain imparted to the skin treatment device. The packaging, applicator or tensioning device may be configured to pivot or rotate to tension the dressing. In some examples, the straining device may be configured to impart and/or maintain a single predetermined or pre-set strain or a plurality of predetermined or pre-set strains, or predetermined maximum or minimum amounts of strain. Features described herein with respect to a packaging assembly, applicator or tensioning device may also be used in any device that is used to strain a dressing. A packaging or applicator, tensioning or straining device that is described as being in an unstrained configuration is in a configuration in which a dressing may be unstrained or relatively less strained when attached to the packaging, applicator, tensioning or straining device. A packaging, applicator, tensioning, or straining device that is described herein as being in a strained configuration, is in a configuration in which a dressing may be strained or relatively more strained when attached to the packaging, applicator, tensioning or straining device, or with respect to an unstrained configuration, when applied to a subject's skin.

Packaging devices, applicators, tensioning devices, and corresponding attachment features may be configured to provide multi-direction strain or additional strain in an orthogonal direction to a dressing.

The packaging device, applicator, tensioning device and/or attachment structure profile may be straight, curved or otherwise varied. For example, the shape of the elements of a device may be configured to follow the shape of the area of the subject's body to which the skin treatment device is to be attached. A packaging device, tensioning device, applicator or elements thereof may be selected or configured to have a profile that has a desirable profile for a particular body location or profile where the skin treatment device is to be placed on a subject's skin. A packaging device, applicator, tensioning device or elements thereof may be selected or configured to closely match a portion of a subject's body profile. The packaging device, applicator or tensioning device and/or an element or segment thereof, may be curved, curvable, flexible, bendable, malleable, deformable, shapeable or movable to provide alternative shapes or profiles of an attached dressing. They may be relatively curved, curvable, flexible, malleable, bendable, deformable, shapeable or movable in at least one direction while being more rigid in another direction.

A variety of locking, latching, securing, attaching or detent mechanisms may be used to maintain the packaging, applicator or tensioning device in a various configurations including but not limited to unstrained, partially strained, strained configurations. A variety of locking, latching or detent mechanisms may be used to maintain a dressing in a variety of configurations including unstrained, partially strained, strained. By locking the packaging, applicator, tensioning device, or dressing in a strained position, a predetermined strain of a given dressing may be achieved. The predetermined amount of strain may be a predetermined absolute percentage of strain or level of force that is independent of the shape and/or size of the treatment site. As a further example, this absolute percentage of strain or level of force may be independent of the minimum strain or force to achieve sutureless wound closure (e.g. a relative strain or force to achieve opposition of the incision edges of a treatment site). Furthermore, the force needed to achieve wound closure is not a predetermined strain or force, since the final level of strain or force is not known until opposition of the incision edges is achieved.

Referring toFIGS.1to5C, a variation of a dressing and packaging assembly100is illustrated. The packaging assembly100comprises a book-like applicator and/or tensioning device120, a dressing assembly110including a dressing130, and a release150configured to release the dressing130from the applicator and/or tensioning device120.

The dressing130comprises an elastic sheet131with one or more adhesive regions comprising a layer of skin adhesive135on a first surface135a. The adhesive used may be, for example, a suitable pressure activated adhesive (PSA), or a non-pressure sensitive adhesive.

The packaging assembly100, applicator or tensioning device120and/or dressing assembly110may be configured to pre-strain the dressing130and/or permit transfer of the pre-strained dressing130to the skin of a subject. The applicator and/or tensioning device120may also provide for a convenient, expeditious or sterile transfer of an adhesive portion of the dressing130to a skin and/or wound site of a subject.

The device120comprises a cover121and a base122. The dressing assembly110is removably coupled or anchored to the device120which may act as a dressing carrier or a support. The cover121may be generally planar and include sides123,124with corresponding edges123a,124aalong its length, and edges121aat opposing ends. The dressing carrier or base122may be generally planar and include sides125,126with corresponding edges125a,126aalong its length and edges122aat opposing ends.

According to some variations, the cover and/or base121,122or elements or segments thereof may be constructed to be sufficiently firm or rigid or less flexible relative to an attached dressing to support an attached dressing until it is applied to a subject as described with respect to the variations herein. Such material may comprise, for example, a plastic, e.g., polypropylene, polycarbonate, polytetrafluoroethylene (PTFE or TEFLON®), LDPE, high-density polyethylene (HDPE), ultra high-molecular weight polyethylene (UHMWPE), polyvinyl chloride (PVC) or acrylic, nylon or a paperboard. The elements or segments may be a laminate of a material, such as a solid bleach sulfate paperboard with a layer of flexible material between layers of paperboard, for example, silicone, polyurethane, LDPE or a rubber material. The material may also be a metal as for example, ductile aluminum or stainless steel. The metal may comprise a foil, ribbon, wire or other form.

Cover121and base122are movably, hingedly or pivotably coupled at sides123,125. For example, a layer of material such as silicone, polyurethane, low-density polyethylene or a rubber material may be glued to each of the cover and base, flexibly attaching them together at sides123,125. Alternative devices and methods may be used to couple the cover121and base122. For example, various composite structures or laminates may be used. Also devices may be constructed out of a single substrate that provides flexibility in some selected regions and rigidity in others, or a relative or absolute flexibility in a first direction with a relative or absolute rigidity in a second direction that may be transverse to the first direction. Although the cover121and base122depicted inFIGS.1to5Chave generally the same size and shape, in other examples, the cover121and base122may be different sizes and/or shapes. Cover121and/or base122may be bendable, foldable, curvable, flexible, malleable or shapeable permitting relatively more even placement on a location with a varying shape or curvature. For example, cover and base121,122as illustrated are each divided into segments127along lengths that are bendable or movable with respect to adjacent segments, permitting flexibility of the device120along its length. The segments127may be constructed of a more rigid material that reduces flexion in a widthwise or other direction. Other configurations that vary the directions of rigidity and/or flexibility may be use. Configurations may include providing rigidity in a direction in which a dressing is strained that is sufficient to create and/or maintain a desired level of strain. The segments127may be coupled by a material, such as an elastomer, e.g., silicone that flexibly holds the segments together in relationship to each other. Other construction may also be used to flexibly couple segments or other elements. The material coupling or binding the cover and base121,122, may or may not be continuous with the material that couples the segments127to adjacent segments127, and may or may not be attached to all or a portion of a side of cover and base121,122. The various attached structures, e.g. the segments and/or the cover and base and coupling elements may provide a structural support for the dressing carrier to be manipulated by a user. Margins between at least a portion of the structural support elements, dressing carrier or backing, and the dressing may be provided at or near edges121a,123a,124a,122a,125a, and/or126a, for example as described further herein. In some further embodiments, the material attaching the cover121and base122may comprise a semi-rigid structure that may be biased to an open or a closed configuration, or a configuration therebetween. In still other variations, the cover121and base122may be attached by any of a variety of articulations, including but not limited to one or more a pin-based hinge joints, rings attached to holes in the cover121and base122, or ball-and-socket joints.

As exemplified inFIGS.5A-5C, a variation of construction of a package is shown. Cover121and base122comprise relatively firm or rigid elements, for example battens121a,121band battens122a,122brespectively that are attached by way of a sheet128of material, such as, e.g., silicone, polyurethane, low-density polyethylene or a rubber material that also flexibly couples cover and base121,122at sides123,125. Segments127may have alternative shapes and construction coupling the segments127together. Thus, the device120may be constructed to bend or curve to varied extents or in multiple directions. Accordingly, a device may be constructed to be used on a specific anatomical location or with varying sizes, or may be constructed to have a shape for a particular situation or individual.

According to some variations each of the cover121and base122is constructed at least in part of a clear plastic, semi-opaque or other material that provides a window portion159through which a wound, incision, or other location may be visualized for accurate placement of the dressing130. The cover121and base122may or may not comprise the same material. The elastic sheet131and adhesive layer135may also be sufficiently clear to permit visualization through them. A more opaque material may be provided on portions of the material to create boundaries of a window159. The segments127may be clear or semi-opaque to provide the window for viewing, positioning, and/or centering the location of a wound or position on skin with respect to the dressing130or for positioning the wound within an optimal or most effective strain zone of the dressing. The boundaries or other markings may assist a user in placing the dressing130in an appropriate position over the wound or incision.

The dressing130of the dressing assembly110has a first side or edge133having a length, and a second side or edge134having a length. The dressing130is coupled to the packaging assembly100along the lengths of the dressing's sides133,134. When the device120is closed, the adhesive layer135faces away from the base122and is covered by a release liner149that is attached to the inside surface177of the cover121. The dressing assembly110also includes an attachment sheet141having a first side143and a second side144. The attachment sheet141couples the dressing130to the cover of the device120which when opened, exerts a straining force on the dressing130through the attachment sheet141. According to some variations, the attachment sheet141is flexible while being relatively inelastic with respect to the dressing130and may be constructed, e.g., out of a low density polyethylene. When assembled, the attachment sheet141is bonded to the elastic sheet131of the dressing at (for example, using a combination of a silicone PSA/acrylic PSA) or near the sides134and143of the dressing130and attachment sheet141respectively. The attachment sheet141is coupled at its side144to the cover121at attachment points137defining a line or area of attachment137aalong the length of the cover121. The dressing130is coupled to the second side124of the base122at a location near the first side133of the dressing130. As such, the elastic sheet131is attached at attachment points138defining a line or area of attachment138aalong a length of the base122. A number of bonding methods or adhesives may be used to attach the attachment sheet141to the cover121, for example, a low surface energy PSA such as an acrylic adhesive.

When the assembly100is in a closed configuration as illustrated inFIG.1and at an open 90 degree configuration as shown inFIG.2, the elastic sheet131is relaxed or unstrained, with the elastic sheet131having an unstrained width w1. As the assembly100is opened to 180 degrees or up to about 360 degrees (e.g. by rotating or pivoting the cover121with respect to the base122), the orthogonal distance increases between lines or areas of attachment137a,138a. According to some variations the assembly is opened to no less than about 180 degrees (minimum angular change) to provide for application of a dressing without interference of the assembly100. When the device120is opened, it exerts a separation force between attachment regions defined by attachment lines or areas137a,138aor corresponding attachment areas. The force tensions the elastic sheet, creating a strain. Tensioning and imparting a strain on the dressing130increases the width between attachment lines or areas137a,138ato w2. The increase in the width, i.e., w2minus w1, may be a percentage of w1or a percent strain as described herein. While straining is illustrated as starting when the cover121is opened about 90 degrees from the base122, the dressing130may be attached to the cover121at a number of locations or in a number of configurations that may vary the cover position or configuration at which straining begins. The edge124aor side124of the cover121may act as a lever arm to provide a mechanical advantage, which may depend, among other things, on the distance of the point of attachment138of the dressing assembly110on the cover to the edge124aof the cover121as well as the angle of the cover121with respect to the base122at which the tensioning of the dressing occurs. Additionally, the point of attachment138of the inelastic attachment sheet141to the cover121may determine amount of strain applied to the dressing, assuming among other things, the length of the attachment sheet141remains the same and the point of attachment137of the dressing assembly110to the base122remains the same

According to one variation, the dressing130may be substantially fixed at one edge, (e.g. at edge134at the side126of the base122) while not being fixed at an opposite edge (e.g., edge133moves when strained with respect to edge125aof base122). When the cover121is opened and the dressing130is strained, the width of the strained dressing may be less than the width of the base122and/or the cover121so that the area of the dressing is located over the area of the base122and or the cover121, i.e. the base122and/or cover121margins outside of the area of the dressing. According to other variations the dressing may be fixed at both edges.

According to some variations, the dressing is sufficiently large with respect to the device120so that when applied to the skin, there is relatively less interference by the device120. According to one example, the width of the strained portion of the dressing may be about 10 mm, about 20 mm, about 30 mm, about 40 mm, or about 50 mm. Other strained dimensions may be used. According other variations, the distance between each of edges133,134of the dressing130and the edges125a,126aof the base122respectively (and/or the edges123a,124aof the cover121) is no greater than about 10 mm, 15 mm or 20 mm. According to some variations, the distance between the edges136a,136bof the dressing and the edges122aof the base is no greater than about 10 mm, about 15 mm or about 20 mm.

According to some variations, edges133,134,136a,136bof the dressing130are at least about 1.0 mm inward of at least a portion of the edges125a,126a, and/or122aof the base122so that the edges125a,126a, and/or122aof the base122may be gripped by a user with a reduced likelihood of touching the dressing130or the adhesive layer135. According to some variations, the ends136a,136bof the dressing130have a margin of at least about 1.0 mm inward of the ends122aof the base122. According to some variations the sides133,134and ends136a,136bof the dressing130have a margin of about 10 mm from the sides125,126and ends122aof the base respectively. According to some variations the sides133,134and ends136a,136bof the dressing130have a margin of about 15 mm from the sides125,126and ends122aof the base respectively. Each of the margins between sides133,134or ends136a,136bof the dressing130and sides125,125, and ends122aof the base122may be different. As illustrated inFIG.3, for example, margins m1and m2are about no less than 3 mm and margin m3is about 15 mm. Similar margins may be provided between the dressing130and the edges121a,123a, and/or124aof the cover121, for example if the edges of the cover121are used alternatively or additionally to grasp the device120or manipulate the dressing130. Then, once the cover121is opened and the adhesive layer135is exposed, the adhesive side of the dressing130may be placed on a skin or wound site using the device120. As shown inFIGS.3and4the cover121and base122may be rotated an additional amount, with respect to each other, e.g., up to approximately 360 degrees from the closed configuration prior to applying the dressing130. A locking mechanism may optionally be provided to lock or secure the device in an open, partially opened or closed position. In some examples, the locking mechanism may comprise magnets, hook-and-look attachment structures, snaps, latches, clips and the like.

The adhesive layer135of the elastic sheet131is protected by a release liner149before the applicator or tensioning device120is opened. The release liner149is attached or glued to the inside surface177of the cover121so that when the cover121is opened as shown inFIG.2, and is separated from the base122(prior to straining the elastic sheet131), the release liner149is pulled away from the elastic sheet131exposing the adhesive layer135. Alternatively, as shown inFIG.6, a release liner149amay be provided on the adhesive layer135that is not attached to the cover121. When the device120is opened, and prior to straining the dressing130, the release liner149amay be manually removed from the elastic sheet131to expose the adhesive layer135.

After the dressing130is strained, and the liner149or149ais released, the dressing130may be applied to a desired location on a subject's skin. The window159may be used to visualize proper placement. The user may apply pressure to the back side129of the device120to activate the adhesive on the elastic sheet131and/or to apply compression to a wound. Alternatively, if the cover121is rotated to 360 degrees, pressure may be applied to the inside177of the cover121. Once applied to a subject, the elastic sheet131may be released from the packaging, applicator or tensioning device120using a release structure or mechanism150.

The release mechanism150may comprise cutters151each positioned on opposite sides133,134of the elastic sheet131. Each cutter151comprises a blade152on one end153with legs154,155extending to opposing pull tab or tabs156on an opposite end157. The blade152comprises a sharp surface that may be generally v-shaped or otherwise shaped. The blade may be constructed, e.g., of stainless steel, ceramic or hard plastic. The blade152and the pull tabs156each extend proud of the ends136a,136bof elastic sheet131, respectively and ends122aof the base122. Cutters151are attached to the dressing assembly110in a manner that defines general cutting paths162,163(depicted best inFIG.5A) along which the blades152are pulled by tabs156to cut the dressing assembly110to release the dressing130. In some variations, the dressing may be scored, perforated or otherwise configured to facilitate separation by the release mechanism.

As best shown inFIGS.5B and5C, tubes164,165for receiving and guiding legs154,155respectively of a cutter151, are positioned along the side133of the elastic sheet131. The tubes164,165may be positioned so that the cutting path162is between the tube164and the tube165. The tube165is coupled, e.g., glued to the adhesive surface135of the elastic sheet131at a location closer to the side133than the cutting path162. The tube164is coupled to the back surface139of the elastic sheet131by way of the attachment sheet141, which is also coupled to the elastic sheet131at a location closer to the side133than the cutting path162. The tube164is coupled to a free end145of the attachment sheet141that extends inward of the cutting path162with respect to the side133. Thus, the tube164may be positioned inside of the cutting path162without being attached to the elastic sheet131inside of the cutting path162. This allows the dressing130to be released from the remainder of the packaging assembly100including the cutter151with tube164and attachment sheet141. A protective member170is attached, e.g. glued to the top of tube165. The protective member170includes a ledge171that extends over the cutting path162so that when the adhesive layer135is positioned on the skin of a subject and the cutter151is actuated, the skin is protected from the blade152.

Tubes174,175for receiving and guiding legs154,155respectively are positioned along the side134of the elastic sheet131. The tubes174,175are positioned so that the cutting path163is between the tube174and the tube175. The tube175is coupled, e.g., glued to the adhesive surface135of the elastic sheet131at a location closer to the side134of elastic sheet131than the cutting path163. The tube174is coupled to the back surface139of the elastic sheet131by way of the extender sheet146. The tube174is coupled to a free end147of the extender sheet146that extends inward of the cutting path163with respect to the side. Tube174is also coupled to the elastic sheet131at a location closer to the side134than the cutting path163. Thus the tube174may be positioned inside of the cutting path163without being attached to the elastic sheet131inside of the cutting path163. This allows the dressing130to be released from the remainder of the packaging assembly100including the cutter151with tube175and extender sheet146. A protective member170is attached, e.g., glued to the top of tube175. The protective member170includes a ledge171that extends over the cutting path163so that when the adhesive layer135is positioned on the skin of a subject and the cutter151is actuated, the skin is protected from the blade152.

The inside of the tubes164,165,174,175may be coated with a lubricious material, e.g. with Kapton tape. The guiding legs154,155may be constructed of a low friction material such as, e.g., HDPE or UHMWPE, so the legs154,155may readily slide in the tubes164,165,174,175to permit smooth cutting of the dressing130from the remainder of the packaging assembly100.

When the dressing130is strained and the adhesive135is exposed, the dressing130may be applied with the adhesive side135towards the skin of a subject. The side133of the elastic sheet may then be released from the applicator by pulling the tabs146to draw the blade152across cutting path162. Also, the side134of the elastic sheet may then be released from the applicator by pulling the tabs146to draw the blade152across cutting path163. Thus the elastic sheet131is released from the packaging100(including the release150).

Referring toFIGS.7to9, another variation of a dressing and packaging assembly200is illustrated. The packaging assembly200comprises an applicator and/or tensioning device220and a dressing assembly210including a dressing230. The dressing230comprises an elastic sheet231with one or more adhesive regions comprising a layer of skin adhesive235. The adhesive used may be, for example, a suitable pressure activated adhesive (PSA), or a non-pressure sensitive adhesive.

The packaging assembly200, applicator or tensioning device220, and/or dressing assembly210may be configured to pre-strain the dressing230and/or permit transfer of the pre-strained dressing230to the skin of a subject. The applicator or tensioning device220may also provide for a convenient sterile transfer of an adhesive portion of the dressing to a skin and/or wound site of a subject.

The device220may comprise a cover221and a base222. The dressing assembly210is removably coupled or anchored to the device220, and may serve as a dressing carrier. The cover221may be generally planar and include sides223,224with corresponding edges223aand224adefining its length and edges221aat opposing ends. The base222may be generally planar and include sides225,226with corresponding edges225aand226adefining its length and edges222aat opposing ends.

According to some variations, the cover and/or base221,222or elements or segments thereof may be constructed to be sufficiently firm or rigid or less flexible relative to an attached dressing to support an attached dressing until it is applied to a subject as described with respect to the variations herein. Such material may comprise, for example, a plastic, e.g., polypropylene, polycarbonate, PTFE, LDPE, HDPE, UHMWPE, PVC or acrylic, nylon or a paperboard. The elements or segments may be a laminate of a material, such as a solid bleach sulfate paperboard with a layer of flexible material between layers of paperboard, for example, silicone, polyurethane, low-density polyethylene or a rubber material, The material may also be a metal as for example, ductile aluminum or stainless steel. The metal may comprise a foil, ribbon, wire or other form. The other variations as described for application or tensioning device100may be applied to device200also.

The cover and base221and222may be movably, pivotably, bendably or hingedly coupled at sides223,225in a manner similar to that described with respect to cover and base121,122herein and may be constructed in a manner similar to cover and base121,122herein, among other things, with segments227similar to segments127and dressing230attached to device220and strained by device in a similar manner as dressing130is attached to device120.

The various attached structures, e.g. the segments and/or the cover and base and coupling elements may provide a structural support for the dressing carrier to be manipulated by a user. Margins between at least a portion of the structural support elements, dressing carrier or backing and the strained or unstrained dressing may be provided at or near edges221a,223a,224a,222a,225a, and/or226a, such as, for example, margins m1, m2, m3shown inFIG.3herein.

According to some variations, each of the cover221and base222is constructed at least in part of a clear plastic, semi-opaque or other material that provides a window portion259through which a wound, incision or other location may be visualized for accurate placement of the dressing230. The cover221and base222may or may not comprise the same material. The elastic sheet231and adhesive layer235may also be sufficiently clear to permit visualization through them. A more opaque material may be provided on portions of the material to create boundaries of a window. Segments227may be clear or semi-opaque to provide a window for viewing, positioning, and/or centering the location of a wound or position on skin with respect to the dressing230or for positioning the wound within an optimal or most effective strain zone of the dressing. The boundaries or other markings may assist a user in placing the dressing in an appropriate position over the wound or incision.

The dressing assembly210also includes an attachment sheet241, attachment sheet251, and a dressing release structure or mechanism250comprising pull tabs246as described in more detail herein. The dressing230of the dressing assembly210has a first side233having a length, and a second side234having a length. When the device220is closed, the adhesive layer235faces away from the base222and is covered by a release liner249that is attached to the inside surface277of the cover221.

The attachment sheet241has a first side243and a second side244. The attachment sheet241couples the dressing230to the cover221of the device220near the second side234of the dressing230. The cover221, when opened, exerts a straining force on the dressing230through the attachment sheet241. The attachment sheet241is coupled at its side244to the cover221at attachment points237, which may be provided as an attachment line or area237a, for example, by bonding with a low surface energy PSA such as an acrylic adhesive. When assembled, the attachment sheet241is bonded to the elastic sheet231of the dressing230at section265of attachment sheet241at or near the side243of the attachment sheet241, for example, using a combination of a silicone PSA/acrylic PSA. The attachment sheet251has a first side253and a second side254. The attachment sheet251couples the dressing230to the base222of the device220near the first side233of the dressing230. The attachment sheet251is coupled at its side254to the base222at attachment points238defining the attachment line or area238a, for example, by bonding with a low surface energy PSA, such as an acrylic adhesive. When assembled, the attachment sheet251is bonded to the elastic sheet231of the dressing at section265of attachment sheet251at or near the side253of the attachment sheet251, for example, using a combination of a silicone PSA/acrylic PSA.

Dressing230has unattached portions or edges255at its sides233,234where the elastic sheet231is free from the attachment sheets241,251respectively. Accordingly, the dressing230is not strained at unattached portions255. The pull tabs246are each coupled to ends281,282of the device220. Each pull tab246comprises a top section247and bottom section248. The bottom sections248are attached to the base222or cover221as illustrated while top sections247are adjacent but unattached to the dressing230.

According to some variations, the attachment sheets241,245are flexible while being relatively inelastic with respect to the dressing230and may be constructed, e.g., out of a low density polyethylene. The attachment sheets241,245may be manufactured to be tearable along the material length while providing tensile strength in other directions, in particular in the tensioning direction of the material of the attachment sheet241(direction in which dressing is tensioned, stressed or strained). An example of such material is an LDPE polymer which is produced by an extrusion process that creates a directionally biased grain whereby the material is tearable with the direction of the grain, but has a relative resistance to tearing in the direction transverse to the grain. The pull tab246may start a tear at a notch in the attachment sheet241or251that is to be completed along lines262. The attachment sheets241,251may additionally or alternatively comprise a material such as an LDPE with perforations formed along tear lines262.

Similar to assembly100herein, when the assembly200is in a closed configuration and at an open 90 degree configuration as shown inFIG.7, the elastic sheet231is relaxed or unstrained, with the elastic sheet231having an unstrained width w3. As the assembly200is opened to 180 degrees or up to 360 degrees (e.g. by rotating or pivoting the cover221with respect to the base222), the orthogonal distance increases between lines or areas of attachment237a,238a. When the device220is opened, it exerts a separation force between attachment regions defined by attachment lines or areas237a,238bor corresponding attachment areas. The force tensions the elastic sheet231creating a strain.

Tensioning and imparting a strain on the dressing230increases the width between attachment lines or areas237a,238ato widthw4. The increase in the width (i.e. width w4minus width w3) may be a percentage of w3or a percent strain as described herein. While straining is illustrated as starting when the cover221is opened about 90 degrees from the base222. The dressing230may be attached to the cover221at a number of locations or in a number of configurations that may vary at which position or configuration the cover222may be when the straining begins.

As shown inFIGS.8to8B, the cover221and base222may be rotated an additional amount, with respect to each other, e.g., up to approximately 360 degrees from the closed configuration prior to applying the dressing230. According to some variations the assembly is opened to no less than about 180 degrees (minimum angular change) to provide for application of the dressing without interference from the assembly.

Then, once the cover221is opened and the adhesive layer235is exposed, the adhesive side of the dressing230may be place on a skin or wound site using the device220. The cover221and base222may be rotated an additional amount, with respect to each other, e.g., up to approximately 360 degrees from the closed configuration prior to applying the dressing230. The orientation of the cover221at which the dressing230begins to strain may be varied, e.g. by varying the attachment location of the dressing assembly210to the cover221. A locking mechanism may optionally be provided to lock or secure the device in an open, partially opened or closed position. In some examples, the locking mechanism may comprise magnets, hook-and-loop attachment structures, snaps, latches, clips and the like.

The adhesive layer235of the elastic sheet231is protected by a release liner249before the applicator and tensioning device220is opened. The release liner249is attached to the inside surface277of the cover221so that when the cover221is opened and is separated from the base222, (prior to straining the elastic sheet231) the release liner249is pulled away from the elastic sheet231exposing the adhesive layer235prior. Alternatively, as shown inFIG.6, a release liner149amay be provided on the adhesive layer235that is not attached to the cover221. When the device220is opened, but prior to straining, the release liner149amay be manually removed from the elastic sheet231to expose the adhesive layer235.

After the liner249or149ais released and the dressing231is strained, the dressing230may be applied to a desired location on a subject's skin. The window may be used to visualize proper placement. The user may apply pressure to the back side229of the device220to activate the adhesive on the dressing231and/or to apply compression to a wound. If the cover221is rotated to 360 degrees, pressure may be applied to the inside277of the cover221. Once applied to a subject, the dressing230may be released from applicator or tensioning device220using the release mechanism250.

The pull tabs246of the release mechanism250each extend proud of the end236aof elastic sheet231. Each release pull tab246is attached to the dressing assembly110in a manner that defines tear paths262along which the tabs246are pulled to separate the dressing230from the device. Notches or perforations may be made in the attachment sheets241,251that facilitate tearing along paths262.

The dressing230is applied to a subject. The dressing230may then be released from the device220by pulling the tabs246to draw the tabs246across paths262of the attachment sheets241,251. The sections245of the attachment sheets241,251that bonded to the pull tabs246are thereby separated from the attachment sheets thereby separating the sections265of the attachment sheets that are attached to the dressing230are from the remainder of the attachment sheets241and251that are attached to the cover221and base222respectively. Thus, the dressing230is released from the remainder of the packaging100as shown inFIG.9. Sections265of the attachment sheets241,251may remain on the back surface239of the silicone sheet231as shown inFIG.9. Unattached sections245of the elastic dressing230are unstrained and may be free from the adhesive of the adhesive layer235(or may have a reduced amount of adhesive thereon). Thus less stress occurs at the unattached sides or edges defined by sections245.

Referring toFIGS.10to12B, a dressing and packaging assembly300is illustrated. The packaging assembly300comprises a packaging device applicator320and a dressing assembly310including a dressing330.

The packaging device or applicator320is configured to permit transfer of the dressing330to the skin of a subject and may also provide for a convenient, expeditious or sterile transfer of an adhesive portion of the skin treatment device to a skin and/or wound site of a subject.

The packaging device or applicator320comprises a cover321and a bottom element, dressing carrier or base322, to which dressing assembly310is removably coupled or anchored. The cover321may be generally planar and include sides323,324with corresponding edges323a,324adefining its length and edges321aat opposing ends. The base322may be generally planar and include side325,326with corresponding edges325a,326adefining its length and edges322aat opposing ends.

According to some variations, the cover321and base322are constructed in part of a relatively inflexible material, e.g., with respect to an attached dressing330. Such material may comprise, for example, a plastic, paperboard or a laminate of a material, or metal as described herein with reference to cover121and base122. The cover or base may be constructed in a manner as described, for example, with respect to the various applicator, tensioning devices or dressing carriers shown inFIGS.1to22Bherein. The cover321and base322may or may not comprise the same material.

Cover321and base322may be movably, pivotably, bendably or hingedly coupled at sides323,325and otherwise constructed in a manner similar to that described herein with respect to cover121and base122. The packaging device or applicator320may include a window portion359through which a wound, incision, or other location may be visualized for accurate placement of the dressing330in a manner similar to that described herein with respect to the use of windows159,259.

The assembly300is constructed including a dressing assembly310with a skin dressing device330. The dressing assembly310also includes a dressing release structure or mechanism350which may be a release device such as various release and removal structures described herein with reference toFIGS.1to22B. The dressing330may comprise a variety of dressing materials, including but not limited to elastic bandages, gauze type bandages, hydrocolloids. The various structures, e.g. the segments and/or the cover and base and coupling elements may provide a structural support for the dressing carrier to be manipulated by a user. Margins between at least a portion of the structural support elements, dressing carrier or backing and the dressing may be provided at or near edges321a,323a,324a,322a,325a, and/or326a, for example as described herein.

When assembled with the packaging device or applicator320, the dressing330is coupled to the base. A length of the dressing330adjacent its first side333is bonded to a length of the base322adjacent its side324and outside of release350. Also a length of the dressing330adjacent its second side334is coupled to a length of the base322adjacent its side325and outside of release350. An attachment sheet similar to sheets141,146or241,251may be used to attach sides333,334of dressing330to the base322. The adhesive layer335faces away from the cover321and base322when the applicator320is opened.

According to variation, the dressing330is sufficient large with respect to the device320so that when applied to the skin, there is relatively less interference by the device320. According to one example, the width of the strained portion of the dressing may be about 20 mm, about 30 mm, about 40 mm, or about 50 mm. According other variations, the distance between each of edges333a,334aof the dressing330and the edges325a,326aof the base322respectively (and/or the edges323a,324aof the cover321) is no greater than about 10 mm, 15 mm or 20 mm. According to variations the distance between the edges336a,336bof the dressing and the edges322aof the base is no greater than about 10 mm, about 15 mm or about 20 mm.

According to some variations, edges333,334,336a,336bof the dressing330are at least about 3 mm inward of at least a portion of the edges325a,326a, and/or322aof the base322so that the edges325a,326a, and/or322aof the base322may be gripped by a user with a reduced likelihood of touching the dressing330or the adhesive layer335. According to some variations, the ends336a,336bof the dressing130have a margin of at least about 3 mm inward of the ends322aof the base322. According to some variations the sides333,334and ends336a,336bof the dressing330have a margin of about 10 mm from the sides325,326and ends322aof the base respectively. According to some variations the sides333,334and ends336a,336bof the dressing330have a margin of about 15 mm from the sides325,326and ends322aof the base respectively. Each of the margins between edges333,334or ends336a,336bof the dressing330and sides325,325, and ends322aof the base322may be different. As illustrated inFIG.3, for example, margins m1and m2are about no less than 3 mm and margin m3is about 15 mm. Similar margins may be provided between the dressing330and the edges322a,325a, and/or326aof the base322, Also similar margins may be provided between the dressing330and the edges321a,323a, and/or324aof the cover321, for example if the edges of the cover321are used alternatively or additionally to grasp the device320or manipulate the dressing330.

The adhesive layer335on the dressing330may be protected by a release liner349before the packaging device or applicator320is opened. The release liner349may be attached to the inside surface377of cover321so that when the cover321is opened or is separated from the base322, the release liner349is pulled away from the dressing330exposing the adhesive layer335. The release liner349may also be a protective liner that protects or covers the dressing prior to application. For example, the liner may cover a dressing to which a substance or medicament or other agent is applied. One or more hemostatic or coagulative agents may be applied to, or otherwise integrated with dressing to help reduce bleeding. Potential agents include chitosan, calcium-loaded zeolite, microfibrillar collagen, cellulose, anhydrous aluminum sulfate, silver nitrate, potassium alum, titanium oxide, fibrinogen, epinephrine, calcium alginate, poly-N-acetyl glucosamine, thrombin, coagulation factor(s) (e.g. II, VII, VII, X, XIII, Von Willebrand factor), procoagulants (e.g. propyl gallate), antifibrinolytics (e.g. epsilon aminocaproic acid), and the like. In some variations, the agents may be freeze-dried and integrated into the dressing and activated upon contact with blood or other fluid. In some further variations, an activating agent may be applied to the dressing or the treatment site before the dressing is used on the subject. In still other examples, the hemostatic agent may be applied separately and directly to the wound before application of the dressing, or after application to the dressing via a catheter or tube. The devices may also comprise one or more other agents that may be any suitable agent that may be useful in aiding in some aspect of the wound healing process. For example, the active agent may be a pharmaceutical compound, a protein (e.g., a growth factor), a vitamin (e.g., vitamin E), or combinations thereof. Of course, the devices may comprise more than one medicament or agents, and the devices may deliver one or more medicaments or agents. An example of such medicament may include, but is not limited to various antibiotics (including but not limited to cephalosporins, bactitracin, polyxyxin B sulfate, neomycin, polysporin), antiseptics (such as iodine solutions, silver sulfadiazine, chlorhexidine), antifungals (such as nystatin), antiproliferative agents (sirolimus, tacrolimus, zotarolimus, biolimus, paclitaxel), grow factors (such as VEGF) and other treatments (e.g. botulism toxin). The cover321may be pulled away or separated in a number of manners. The cover321may be opened like a cover of a book. Similar to devices120and220,420,520,620,720,820,920,1020herein, the elements321,322may be rotated sufficiently to separate the release liner349and up to approximately 360 degrees allowing the exposed adhesive side335of the dressing330to be place on a skin or wound site using the packaging device or applicator320. According to some variations the assembly300is opened to no less than about 180 degrees (minimum angular change) to provide for application of the dressing without interference of the assembly300. Alternatively, for example, the cover321may be attached to the base322by an adhesive and may be peeled off of the dressing330or the base322to which the dressing330is coupled. The cover321itself may be a removable, or separable release liner that may be peeled from the base322. Alternatively, as shown inFIG.6, a release liner149amay be provided on the adhesive layer335that is not attached to the cover321. When the device is opened, the release liner149amay be manually removed from the dressing330to expose the adhesive layer335. In such case, the cover321may be omitted. After the device300is opened to position shown inFIG.11or12A and12B, the dressing330may be applied to a desired location on a subject's skin. The window359may be used to visualize proper placement. A locking mechanism may optionally be provided to lock or secure the device in an open, partially open, or closed position. In some examples, the locking mechanism may comprise magnets, hook-and-look attachment structures, snaps, latches, clips and the like as well as adhesives, or other adhesive structures. A compressive force may be applied to the back side378of base322or inside377of cover if rotated approximately 360 degrees. Once applied to a subject, the dressing330may be released from packaging device or applicator320using a release mechanism350. The release mechanism350may include a cutting element or a perforated element as described for example with respect to devices150and250herein. The release mechanism may further include one more release elements described herein and show inFIGS.1to22B.

FIG.13illustrates an alternative packaging or applicator420that may be used in any of the embodiments herein including device elements or features that may be substituted for device elements or features of devices120,220or320,520,620,720,820,920,1020,1120,1220.FIG.13illustrates a cover421and a dressing carrier or base422that are constructed of a single substrate out of a material such as nylon and/or polyethylene or a metal. The device420may be manufactured from a single mold and/or may have portions cut out of the substrate, slots, grooves, scoring or other openings or variations in thickness of the substrate at different locations. The cover421and base422each comprise slots428that form elements such as segments427. The slots428permit flexion of the device420allowing it to conform to a subject's body contours where an attached dressing is to be applied. Cover421and base422are coupled to each other by way of connection features429that are formed in the substrate. The cover421and base422are hingedly or pivotably movable with respect to each other by virtue of slots430that are formed adjacent connection features429, to permit flexion or movement of the connector features429and thus the cover421and base422with respect to each other. As mentioned with respect to device100, in other variations, slots430may comprise grooves or other structures providing a reduced thickness relative to the cover421and base422. The device420may include a release mechanism as described with respect toFIGS.1A-22Bherein. The device420may be used in the same manner as the devices described with reference toFIGS.1A to22Bherein and may attach a dressing in the same manner as described with respect to devices described with reference toFIGS.1A to22Bherein.

The various structures, e.g. the segments and/or the cover and base and coupling elements, slots and grooves may provide a structural support as well as flexibility for the dressing carrier to be manipulated by a user. Margins between at least a portion of the structural support elements, dressing carrier or backing and an attached dressing may be provided at or near edges421a,423a,424a,422a,425a, and/or426a, for example as described further herein.

FIG.14illustrates an alternative packaging or applicator device520that may be used in any of the devices described herein with reference toFIGS.1A to22B. A cover portion521and a dressing carrier or base portion522may be constructed of a laminate structure530. A first layer531of the laminate structure530comprises a paperboard or other support material such as a plastic material or metal having slots528formed widthwise across each of the cover521and base522. The slots528form segments527that permit flexion of segments527of the device520allowing it to conform to a subject's body contours where an attached dressing is to be applied. The first layer531further comprises lengthwise slot529between the cover521and base522formed in the first layer531. The first layer531further comprises tabs540with openings that are used in assembly of the device520and are removed after assembly so that the cover521and base522are separated by slot529and are no longer connected by the first layer531. The second layer532of the laminate comprises an adhesive material such as a PSA acrylic, rubber or silicone adhesive. The second layer532may or may not be about 0.001 to 0.006 thick. A flexible strip534of material is positioned along the length of the device520over the slot529and connecting the cover521and base522. The cover521and base522are flexibly and hingedly or pivotably coupled and movable with respect to each other by way of the strip534of material over the slot529to permit flexion or movement of the cover521and base522with respect to each other. The flexible strip534is attached with an adhesive535to a third layer533that comprises a thin material such as paper or plastic that may have generally a similar outline as the first layer531and that holds the structure of the device520, including segments527, together.

The device520may include a release mechanism, dressing attachment and may be used in the same manner devices and assemblies as described with respect toFIGS.1A-22Bherein.

The various structures, e.g. the segments, adhesive structures, laminate layers and/or the cover and base and coupling elements, slots and grooves may provide structural support as well as flexibility for the dressing carrier, to facilitate manipulation by a user. Margins between at least a portion of the structural support elements, dressing carrier or backing and an attached dressing may be provided at or near edges521a,523a,524a,522a,525a, and/or526a, for example as described further herein.

Referring toFIGS.15A to15J, a variation of a dressing and packaging assembly600is illustrated. The packaging assembly600comprises an applicator and/or tensioning device620and a dressing assembly610including a dressing630. The dressing630comprises an elastic sheet631, with one or more adhesive regions comprising a layer of skin adhesive such as described herein.

The features inFIGS.15A to15Jmay be used in any of the variations herein including device elements or features that may being substituted for device elements or features of devices and assemblies shown inFIGS.1A to22B.

The packaging assembly600applicator, tensioning device620and/or dressing assembly610may be configured to pre-strain the dressing630and/or permit transfer of the pre-strained dressing630to the skin of a subject. The applicator or tensioning device620may also provide for a convenient sterile transfer of an adhesive portion of the dressing to a skin and/or wound site of a subject.

The device620comprises a cover621and a base622. The dressing assembly610is removably coupled or anchored to the device620which may act as a dressing carrier. The cover621may be generally planar and include sides623,624with corresponding edges623aand624bdefining its length and edges621aat opposing ends. The base622may be generally planar and include sides625,626with corresponding edges625aand626adefining its length and edges622aat opposing ends.

According to some variations, the cover621and/or base622or elements or segments thereof may be constructed to be sufficiently firm or rigid or less flexible relative to an attached dressing to support an attached dressing until it is applied to a subject as described with respect to the variations herein. The materials and construction of the applicator or tensioning device620, dressing630and packaging600may be of similar to the packaging assemblies and/or dressings described in variations herein and shown inFIGS.1A to22B.

The cover621and base and622may be movably, pivotably, bendably or hingedly coupled at sides623,624. For example, a layer of material627such as silicone, polyurethane, low-density polyethylene or a rubber material may be glued to each of the cover and base, flexibly attaching them together at sides623,625. The device620may be constructed in a manner similar to that described with respect to other devices herein and shown inFIGS.1A to22Band may be constructed in a similar manner as described herein including but not limited to with respect to materials, segmentation, strength and flexibility, visualization, straining mechanisms, and release liners.

The dressing assembly610also includes an attachment sheet641, attachment sheet651. The attachment sheet641has a first side643that is attached to the second side634of the dressing by way of an adhesive structure670such as polyimide film or tape (e.g. KAPTON® by DuPont™) or a peelable adhesive. Adhesive structures herein may include but are not limited to KAPTON® tape or peelable adhesive configured to provide low skin trauma after repeated skin contact or a soft skin adhesive, made of material such as silicone adhesive, silicone gel, or acrylic adhesive. The adhesive structure or KAPTON® tape also comprises a material that is able to adhere to the attachment sheets to impart strain to the dressing when the attachment sheets are separated from each other, while being peelable from a selected dressing material.

As shown inFIG.15J, the attachment sheet641and side634of the dressing may be attached on same side671of the adhesive structure670with the attachment sheet641overlapping but unattached to the dressing631.

The attachment sheet641has a second side644that is coupled to the cover621of the device620for example, by bonding with a low surface energy PSA, such as an acrylic adhesive. Attachment sheet641may also have a score or perforation681between its attachment to the adhesive structure670and its attachment to the cover621. After the dressing has been strained, the perforation681is located at the seam between the cover621and the base622, or over the inside surface of the cover621.

The attachment sheet651may be coupled at its side654to the back side698of the base622for example, by bonding with a low surface energy PSA, such as an acrylic adhesive. The side653of attachment sheet651may be attached to the side633of the dressing by way of an adhesive structure680such as KAPTON® tape or a peelable adhesive, and in a manner similar to the adhesive structure670that attaches the side654of the dressing630to the attachment sheet641. The attachment sheet651may include a pull tab688that is located on the back side698of the base adjacent and inside of the attachment zone655of the attachment sheet651to the back of the base652.

The cover621, when opened, exerts a straining force on the dressing630through the attachment sheet641.

According to some variations, the attachment sheets641,651are flexible while being relatively inelastic with respect to the dressing630and may be constructed, e.g., out of a low density polyethylene. The attachment sheets641,651may be manufactured to be tearable along the material length while providing tensile strength in other directions, in particular in the tensioning direction of the material of the attachment sheet641(direction in which dressing is tensioned, stressed or strained). An example of such material is an LDPE polymer which is produced by an extrusion process that creates an anisotropic or directionally biased grain whereby the material is tearable with the direction of the grain, but has a relative resistance to tearing in the direction transverse to the grain.

FIG.15Ashows the assembly600in an unstrained configuration. An adhesive tape683is exposed on the inside surface694of the base622. A skin adhesive layer on the elastic sheet631of the dressing630may be protected by a release liner similar to release liner149aherein before the applicator or tensioning device620is opened

FIG.15Bshows the assembly600in an opened and strained configuration. As shown inFIG.15B, when strained, the perforation681on the attachment sheet is aligned with the edges623aand625aof the cover621and base622, respectively. A portion641aof the attachment sheet641interfaces with the adhesive tape683attaching portion641ato the base622and holding the dressing630in the strained configuration. A release liner645is attached to the underside of the attachment sheet641between the attachment to the cover621and the perforation681. The liner645prevents the portion of the attachment sheet641that interfaces the cover621from adhering to the adhesive tape683.

The cover621and base622may be separable from each other by way of, for example, a perforation682in the layer627that couples the cover621to the base622and by separation of the sheet641along perforation681.FIG.15Cshows the assembly600with the cover621separated from the base622. The strained dressing630may be applied to a subject's skin using the base622as an applicator.

FIG.15Dillustrates the back side698of the base622in a position of applying the dressing630toward the skin of a subject. As shown, the edge654of attachment sheet651may be wrapped around from the inside694of the base622to the back side698where it is attached. A tear strip may be attached to the attachment sheet651between the attached edge and an unattached middle section. The pull tab688or tear strip may be pulled to detach the base622from the remainder of the dressing assembly as shown inFIG.15E. After the tab688is pulled, an unattached portion651aof the attachment sheet651is freed from the base622. After the base is removed, the remaining portions of the attachment sheets641,651may be removed by peeling the KAPTON® tape off of the dressing630.FIG.15Fshows the dressing630after removal of the remainder of the dressing assembly.

FIGS.15G to15Jillustrate a configuration of the dressing assembly610as the KAPTON® tape or adhesive structures670,680and attachment sheets641,651are removed from the dressing630.FIGS.15G and15Jshow the orientation of the KAPTON® tape or adhesive structures670,680as they are peeled in a direction from inside the dressing630towards the sides633,634of the dressing630, or in a direction of dressing strain.FIG.15Hshows the first structure670peeled away from the inside of the dressing across the side633of the dressing.FIG.15Ishows the first adhesive structure670removed from the dressing630. The second adhesive structure680may be removed in a similar manner.

FIGS.16A to16Dillustrate an alternative dressing assembly710in a configuration in which a dressing assembly710is separated from the applicator or tensioning device in a manner similar to that described with respect toFIGS.15A to15J.FIG.16Aillustrates a first adhesive structure770and a second adhesive structure780, each comprising KAPTON® tape or a peelable adhesive structure used to attach attachment sheets741,751to the dressing730, As shown inFIG.16Athe unattached ends of the adhesive structures770,780are oriented away from the dressing730. As shown inFIG.16B, the second adhesive structure780is peeled inwardly and inFIG.16C, is removed.

FIGS.17A to17Dillustrate an alternative dressing assembly configuration in which a dressing assembly810is separated from the applicator or tensioning device in a manner similar to that described with respect toFIGS.15A to15J.FIG.17Dillustrates a first adhesive structure870and a second adhesive structure880, each comprising KAPTON® tape or a peelable adhesive structure used to attach attachment sheets841,851respectively to the dressing830. As shown inFIGS.17A and17D, the adhesive structures870,880are attached to the dressing830with adhered length891. An additional length892is wrapped 180 degrees about the adhered length891. The additional length892has an end893that extends proud of the dressing830for easy access and removal. As shown inFIG.17B, the first adhesive structure870may be pulled using the end893, in a direction that is in part perpendicular to the direction of strain, to remove the attachment structures841,851and adhesive structure870from the dressing830as further shown inFIG.17C.

FIGS.18A to18Iillustrate a variation of a dressing and packaging assembly900. The packaging assembly900comprises an applicator and/or tensioning device920and a dressing assembly910including a dressing930. The device920comprises a cover921and a base922. The dressing assembly910is removably coupled or anchored to the device920which may act as a dressing carrier. The cover921may be generally planar and include sides923,924with corresponding edges923aand924adefining its length and edges921aat opposing ends. The base922may be generally planar and include sides925,926with corresponding edges925aand926adefining its length and edges922aat opposing ends.

The dressing assembly910also includes an attachment sheet941and attachment sheet951. The attachment sheet941has a first side943that is attached to the second side934of the dressing by way of an adhesive structure970such as KAPTON® tape or a peelable adhesive. Adhesive structures herein may include but are not limited to KAPTON® tape or peelable adhesive configured to provide low skin trauma after repeated skin contact or a soft skin adhesive, made of material such as silicone adhesive, silicone gel, or acrylic adhesive. The adhesive structure or KAPTON® tape also comprises a material that is able to adhere to the attachment sheets to impart strain to the dressing when the attachment sheets are separated from each other, while being peelable from a selected dressing material.

As shown inFIG.18J, the attachment sheet941and side934of the dressing are attached on same side971of the adhesive structure970with the attachment sheet941overlapping but unattached to the dressing931. The attachment sheet941has a second side944that is coupled to the cover921of the device920for example, by bonding with a low surface energy PSA such as an acrylic adhesive. Attachment sheet941may also have a pull tab981in an unattached region between the attachment to the adhesive structure970and attachment to the cover921. After the dressing has been strained, the perforation pull tab981is located at the inside surface960of the cover921or alternatively at the seam between the cover921and the base922.

The attachment sheet951is coupled at its side954to the back side998of the base922for example, by bonding with a low surface energy PSA such as an acrylic adhesive. The side953of attachment sheet951is attached to the side933of the dressing930by way of an adhesive structure980such as KAPTON® tape or a peelable adhesive, and in a manner similar to the adhesive structure970that attaches the side944of the dressing930to the attachment sheet941. The attachment sheet951may include a pull tab988that is located on the back side998of the base adjacent and inside of the attachment zone955of the attachment sheet951to the back of the base952.

According to some variations, the attachment sheets941,951are flexible while being relatively inelastic with respect to the dressing930and may be constructed, e.g., out of a LDPE. The attachment sheets941,951may be manufactured to be tearable along the material length while providing tensile strength in other directions, in particular in the tensioning direction of the material of the attachment sheet941(direction in which dressing is tensioned, stressed or strained). An example of such material is an LDPE polymer which is produced by an extrusion process that creates an anisotropic or directionally biased grain whereby the material is tearable with the direction of the grain, but has a relative resistance to tearing in the direction transverse to the grain.

The cover921, when opened, exerts a straining force on the dressing930through the attachment sheet941.FIG.18Ashows the assembly900in an unstrained configuration, whileFIG.18Bshows the assembly900in an opened and strained configuration which may be applied to the skin. As shown inFIG.18C, when strained, the tab981on the attachment sheet941is located over the inner surface of the cover921(folded back and exposed) and is accessible to a user. After applying the dressing930, the cover921and base922may be removed.

The cover921and base922are separable from each when the tab988is pulled.FIG.18Cshows the assembly with the cover positioned with the dressing face down for example as it would be when applied to the skin of a subject. As shown inFIG.18Dthe tab988is pulled to release the cover921from the remaining dressing assembly910. As shown inFIG.18Ethe cover921is removed from the remainder of the device920, exposing the second pull tab998. As shown inFIG.18F, the second pulled tab998has released the base922from the dressing assembly910with attachment sheets941,951unattached to the base922. As shown inFIG.18G, the base922is removed ant the remainder of the attachment sheets941,951and the adhesive structures970,980may be peeled away from the dressing930as shown ifFIG.18Hwith the dressing remaining on the skin in a configuration as shown inFIG.18I.

Referring toFIGS.19A through19D, a variation of a dressing and packaging assembly1000is illustrated. The packaging assembly1000comprises an applicator and/or tensioning device1020and a dressing assembly1010including a dressing1030.FIG.19Ashows the dressing assembly1010coupled to the applicator or tensioning device1020. The tensioning member or applicator1020may be constructed in a similar manner as the tensioning and applicators described herein and shown inFIGS.1A to22B.

The device1020comprises a cover1021and a base1022. The dressing assembly1010is removably coupled or anchored to the device1020which may act as a dressing carrier. The dressing assembly may be attached to the tensioning member or applicator in a manner similar to the assemblies described herein. The dressing assembly1010includes an attachment sheet1041and attachment sheet1051. The attachment sheet1041has a first side1043that is attached to the second side1034of the dressing1030by way of an adhesive structure1070such described with reference to adhesive structures970,980. The attachment sheet1041has a second side1044that is coupled to the cover1021of the device1020for example, by bonding with a low surface energy PSA such as an acrylic adhesive. Attachment sheet1041also has a ripcord1088stitched along its length at an unattached portion of the attachment sheet1041, between its attachment to the adhesive structure1070and attachment to the cover1021. Various types of stitches may be used including but not limited to a chainstitch or a lockstitch. After the dressing has been strained, the ripcord1088is located at the exposed inner side1090of the cover1021or alternatively at the seam between the cover1021and the base1022.

The attachment sheet1051is coupled at its side1054to the back side of the base1022for example, by bonding with a low surface energy PSA such as an acrylic adhesive. The side1053of attachment sheet1051is attached to the side1033of the dressing by way of an adhesive structure1080such as KAPTON® tape or a peelable adhesive, and in a manner similar to the adhesive structure1070that attaches the side1034of the dressing1030to the attachment sheet1041. The attachment sheet1051includes a ripcord1098that is located between attachment to the adhesive structure1090and attachment to the back of the base. The ends of the ripcords1088,1098extend out of the tensioning member1020for easy accessibility.

FIGS.19A and19Billustrate the dressing assembly1010in an unstrained configuration. The cover1021, when opened, exerts a straining force on the dressing1030through the attachment sheet1041.FIG.19Cillustrates the dressing assembly1010in a strained configuration.

After the dressing is strained and applied, the ripcords1088,1098are pulled to separate the portion of the attachment sheets1041,1051attached to the tensioning device1020from the portions of the attachment sheets1041,1051attached to the dressing1030. The applicator or tensioning device1020may then be removed as shown inFIG.19D. The adhesive structures1080,1090may then be peeled away to remove the remaining portion of the dressing assembly1010and attachment sheets1041,1051, from the dressing as shown inFIG.19E.

Referring toFIGS.20A to20C, a variation is shown of a dressing carrier, tensioning device or applicator1120. The device1120comprises a plurality of segments1130formed by scoring a substrate1150on one side1155of a planar surface. The scores1170may be formed in one or more directions or having one or more shapes, curved or straight. Additionally the scores may be formed on both sides permitting both convex and concave shaping of a device. As illustrated, the scores1170permit shaping of the device or an attached dressing. The scores1170as illustrated are formed on a first side1155of a planar surface of the device while the second side1165is not scored. When a force is applied to the second side1165, the substrate bends. When a force is applied to the first side1155, the substrate1150the device does not flex at the scores1170. The remaining substrate at the scores1170may act as flexion limiter while the scores1170act as a flex element.

When a convex dressing shape is desired for a concave surface, the dressing may be attached on the first side1155so that when the substrate is bent, the dressing forms a convex shape to match a concave contour where the device is to be applied. When a concave dressing shape is desired for a convex body contour, the dressing may be positioned on the second side1165of the substrate1150. So that when the substrate is bent, the dressing forms a concave shape to match a convex body contour where the device is to be applied. Various dressing backings may be provided for different body locations or contours.

According to variations, the score may be orthogonal or have orthogonal components with respect to the segments1127of the carrier, applicator or tensioning device. The segments1127may be similar to segments shown inFIGS.1A to22B.

Referring toFIGS.21A to21D, a variation is shown of a dressing carrier, tensioning device or applicator1220. The device1220comprises a plurality of foam cells1240coupled by and adhesive backing1260. The foam cells1240form a plurality of segments1227that permit flexing in multiple directions so that the device conforms to a curvature, profile or shape of a subject where the dressing is to be applied. The foam may be sufficiently thick to generally provide added column strength for straining a dressing, i.e. a resistance to bending. A backing or support may be provided for straining a dressing, for example constructed of a material with an elastic modulus and appropriate thickness that will, at minimum, counteract the force created by straining the dressing. The dressing strain may be fixed, for example, using an adhesive on the back of a portion of the dressing assembly or attachment sheet. After the dressing is fixed, the backing or support may be removed permitting increased manipulation of the shape of the strained dressing to conform to a greater degree to the shape of the patient's body contours where the dressing is to be applied.

As illustrated, the separations1270between the foam sections permit shaping of the device. The separations1270as illustrated are formed on a first side1255of a planar surface of the device while the second side1265is not scored. When a force is applied to the first side1255, the substrate bends. When a force is applied to the second side1265, the substrate1250the device does not flex at the separations. The remaining substrate at the separations may act as flexion limiter while the scores act as a flex element.

When a convex dressing shape is desired for a concave surface, the dressing may be attached on the first side1255so that when the substrate is bent, the dressing forms a convex shape to match a concave contour where the device is to be applied. When a concave dressing shape is desired for a convex body contour, the dressing may be positioned on the second side1265of the substrate1250. So that when the substrate is bent, the dressing forms a concave shape to match a convex body contour where the device is to be applied. Various dressing backings may be provided for different body locations or contours.

Referring toFIGS.22A and22B, a variation of a dressing and packaging assembly1500is illustrated. The packaging assembly1500comprises an applicator and/or tensioning device1520and a dressing assembly1510including a dressing1530. The packaging assembly1500, applicator or tensioning device1520, and/or dressing assembly1510may be configured to pre-strain the dressing1530and/or permit transfer of the pre-strained dressing1530to the skin of a subject.

The device1520may comprise a cover1521and a base1522. The dressing assembly1510is removably coupled or anchored to the device1520, and may serve as a dressing carrier. The cover1521and base1522are movably, pivotably, bendably or hingedly coupled at sides1523,1524and may be constructed in a manner similar to that described with respect to covers and bases described inFIGS.1A to22B. Attachment regions1541,1551of the dressing assembly1510are attached near free sides1525,1526of cover1521,1522respectively, for example by way of a peelable adhesive or removable adhesive structures. However an attachment sheet or attachment structure described with respectFIGS.1A to22Bherein may be used. The attachment regions1541,1551and or positioning of the dressing1530on the device1520, may be symmetric with respect to a line defined by attachment of sides1523,1524of the cover1521and base1522respectively. As shown inFIG.22B, the dressing1530is strained with the cover1521and base1522are opened. The dressing1530may then be applied to the skin of a subject and the device1520may be peeled away from the dressing1530. In addition or alternatively, the cover1521and base1522may be separated by way of a perforation formed in the substrate of the device1520or a perforation1551formed in an attachment structure1550such as a tape or layer of material that attaches sides1523and1524of the cover1521and base1522respectively.

In some variations, the device1520may optionally comprise an adhesive coating or adhesive tape on the cover1521and/or base1522which may adhere to the dressing1530when the dressing1530is tensioned and the dressing comes in further contact with the cover1521and base1522. In some variations, the adhesive is configured to maintain the dressing1530in a tensioned state and/or against the cover1521and/or base1522. The adhesive coating or adhesive tape may be located along the side regions1523,1524of the cover1521and/or base1522, but many also be provided adjacent to the attachment regions1541,1551. Release liners may also be provided to reduce inadvertent adhesion of the dressing or other structures to the adhesive until activation of the device1520is desired.

According to variations the various assemblies or devices described herein may provide a temporary wound dressing that may be applied before a wound is closed. The assembly may be configured to apply a dressing to a wound and to use the packaging or applicator to apply pressure to the wound before removing or separating the applicator, tensioning device or dressing carrier, base or support from the dressing. According to this variation which may be provided with any of the embodiments described below, the packaging or applicator has sufficient rigidity to distribute a relatively even or firm force to a wound by applying pressure to the packaging or applicator when and/or after the dressing is applied to a wound. According to a variation, such dressing may include a coagulation agent or other agent or medicament, for example as described herein. According to another variation, margins as described herein, are provided on such a device between a dressing and edges used to manipulate the device.

The assemblies or devices described herein may also form a dressing support structure. For example, the dressing support structure may comprise of a plurality of segments of the base structures. The dressing support structure may comprise at least 3 segments that extend at least from a first side of the dressing to a second side of the dressing. The dressing support structure may comprise a plurality of segments such as segments described inFIGS.1A to22Bthat are coupled or formed together. The plurality of segments of a cover described herein may also provide support to a dressing when the cover is folded over 360 degrees with respect to the corresponding base structure.

In other examples, the strained dressing may be provided to the user as pre-strained dressing that is strained at the point-of-manufacture, rather than at the point-of-use. Referring toFIGS.23A to23I, preparation of a pre-strained assembly2351that includes a pre-strained dressing is illustrated. A tensioning device2341used to prestrain the dressing is shown in use inFIGS.23A to23D. Various features and stages of preparing prestrained assembly2351are further shown inFIGS.23E to23I.

The pre-strained assembly2351may comprise a dressing assembly2308and strain maintaining structure or support structure2330. (SeeFIG.23I) The pre-strained assembly2351may be stored for a period of time prior to use.

The dressing assembly2308may include a dressing2310comprising a relatively planar elastic sheet2360defining a plane. The elastic sheet2360may comprise a silicone sheet or other elastic material, for example, as described herein. The dressing assembly2308may further comprise an attachment sheet2304, tensioning sheet2307, a pre-strained assembly release2352and a dressing release2319.

The attachment sheet2304may be configured to attach the dressing2310to a support structure2330by way of engaging element2322. The attachment sheet2304of the dressing assembly2308may include a first engaging wall or element2322extending downward with respect to the plane of the dressing2310and including an inwardly extending hook2323. Engaging element2322may be attached to the attachment sheet2304, for example, with an adhesive. The tensioning sheet2307of the dressing assembly2308may include a second engaging element2324extending downward with respect to the plane of the dressing2310and including an inwardly extending hook2325. The tensioning sheet2307may be configured to attach the dressing2310to the support structure2330by way of engaging element2324. Engaging element2324may be attached to tensioning sheet2307, for example, with an adhesive. The tensioning sheet2307may also be configured to translate tension from the tensioning device2341to the dressing2310to strain the dressing2310.

The pre-strained assembly release2352may be configured to release the pre-strained assembly2351(the dressing2310and support structure2330) from the tensioning device2341(see, e.g.,FIGS.23E and23I). The dressing release mechanism2319may be configured to release the dressing2310from the engaging elements2322,2324(including hooks2323,2325) and thus from the support structure2330. The dressing release mechanism2319may be configured to release the dressing2310after the dressing2310is applied to a subject.

The dressing2310of the dressing assembly2308may have a first edge or side2305having a length, and a second edge or side2306having a length. The dressing2310may be coupled at a first edge or side2305to the attachment sheet2304which may be flexible yet relatively less elastic or in-elastic than the dressing2310. The attachment sheet2304may have a first side2382and a second side2384. When assembled, the attachment sheet2304may be bonded to the elastic sheet2360of the dressing2310at section2375of attachment sheet2304at or near the side2382of the attachment sheet2304, for example, using a combination of a silicone PSA/acrylic PSA. The attachment sheet2304may be coupled at its side2384to engaging element2322and hook2323, for example, by bonding with an adhesive material, e.g., using a combination of a silicone PSA/acrylic PSA. The attachment sheet2304may couple the dressing2310by way of engaging element2322and hook2323, to the support2330near the first side2305of the dressing2310. The dressing2310may be coupled at its second edge or side2306to the tensioning sheet2307which may be flexible yet non-elastic or less elastic than the dressing2310. The tensioning sheet2307may have a first side2372a middle location2373and a second side2374. When assembled, the tensioning sheet2307may be bonded to the elastic sheet2360of the dressing2310at section365of tensioning sheet2307at or near the side2372of the tensioning sheet2307, for example, using a combination of a silicone PSA/acrylic PSA. The tensioning sheet2307may be coupled at a middle location2373to side wall2324and hook2325, for example, by bonding with an adhesive material, for example, using a combination of a silicone PSA/acrylic PSA. When assembled into the pre-strained assembly2351, the tensioning sheet2307may couple the dressing2310by way of side wall2324and hook2325to the support structure2330near the second side2306of the dressing2310. The tensioning sheet2307may be loaded onto the tensioning device2341at the second side2374as described in more detail herein. According to some variations, the attachment sheet2304or tensioning sheet2307may be constructed, e.g., out of a low density polyethylene.

The dressing assembly2308is shown inFIG.23A, positioned over a support structure2330to which it may be removably attached when or after the dressing2310is pre-strained to form the pre-strained assembly2351. The support2330may be generally planar and include sides2335,2336with corresponding edges2335aand2336adefining its length. Other support elements, support structures and/or strain maintaining elements may be used, for example, the sides of the dressing2310or dressing assembly2308may be clamped and a desired distance maintained between the clamps, e.g., using a separating element.

The dressing2310of the dressing assembly2308may be strained, for example, with a tensioning device2341as shown inFIGS.23A to23D. The pre-strained dressing2310may then be stored in a pre-strained configuration for a period of time prior to use. The tensioning device2341may be used at a point of manufacture, by an intermediary, or by an end user. The tensioning device2341may comprise a planar portion2343and a circular portion2344configured to contain a rotating element2345. The rotating element2345may have a middle section2346with a slot2347to receive and engage the tensioning sheet2307of the dressing assembly2308.

InFIGS.23Athe dressing assembly2308may be shown in a first configuration on the tensioning device2341where it is relatively unstrained. The dressing assembly2308may be positioned over support structure2330. This support structure2330may be positioned over the tensioning device2341with the upper surface2333of the support structure2330interfacing the back side2311of the dressing2310. A first edge2335aof the support structure2330and a first side or edge2349of the planar portion2343of the tensioning device2341may be engaged and held by engaging wall2322and hook2323. The second end2336and edge2336aof the support2330may initially be free from engagement with but is in a position interfacing the dressing2310. This may permit the dressing2308to be strained to a desired degree without interference of the support structure2330.

In use, the end2374of the tensioning sheet2307may be inserted into the slot2347in the middle section2346of the rotating element2345of the tensioning device2341. Then the rotating element2345may be rotated until the tensioning sheet2307is engaged. Initially the tensioning sheet2307and dressing2310may be in an unstrained configuration but with minimal slack, when attached to the tensioning device2341. As the rotating element2345is rotated, the dressing2310may be strained as the tensioning sheet2307is pulled in a tensile straining direction with respect to the dressing2310by the rotating element2345.

The dressing2310may be strained by turning the rotating element2345as shown inFIGS.23A-23D. Once the tensioning sheet is loaded as the rotating element2345is turned, the tensioning sheet2307may wrap around the rotating element2345thereby shortening the distance between the rotating element2345and the dressing2310, to stretch or strain the dressing2310. A locking mechanism comprising ratchets2337on the rotating element2345and a pawl2338on the circular portion2344may be used to lock the dressing2310in a strained configuration as shown inFIGS.23B to23D. When the tensioning sheet2307is pulled in a tensile straining direction towards the circular portion2344of the tensioning device2341, the engaging element2324and hook2325may also move in the tensile straining direction. The edges2336aof the support comprises a ramp2336bthat may engage with a ramp2326on the hook2325to guide the edge2336aof the support2330into engagement with the hook2325as the hook2325moves towards the circular portion2344of the tensioning device. (SeeFIGS.23C to23H). The strain of the pre-strained dressing2310may be controlled or determined using measurement elements or marks2342on the rotating element2345the distance between each of which may correspond to an increment of increased strain or distance. Once a dressing assembly2308is loaded on the tensioning device2341, the strain may be determined by the amount the rotating element2345rotates. Each mark2342may correspond to a percentage strain or a distance. A 0% strain may be identified as the position in which the dressing assembly2308is loaded onto the tensioning device2341with no slack and minimal strain or tension. As shown inFIG.23Athe 0% position may be shown where mark2342ais aligned with the pawl2338. As the rotary element2345is rotated, the identified 0% mark2342amay rotate a certain degree which corresponds to a percent strain. Mark2342bas shown inFIG.23Bis aligned with the pawl2338when the dressing is strained to a desired amount x indicated by mark2342b.

The support structure2330may maintain the dressing2310in its strained configuration as shown inFIGS.23B to23Iduring storage where the engaging elements2322,2324and hooks2323,2325engaging the support structure2330, prevent movement of the dressing2310or loss of strain. One or more adhesive regions comprising a layer of skin adhesive2340may be applied to the top surface2312of the dressing2310. The adhesive2340used may be, for example, a suitable pressure activated adhesive (PSA), or a non-pressure sensitive adhesive. The adhesive2340is shown on a dressing2310in an unstrained configuration. However, the adhesive may be applied to the dressing2310after the dressing2310has been strained. A removable liner2350may be placed over the adhesive layer2340. The liner2350may further be selected to maintain the strain in the dressing2310. Such liner may comprise rigid or semi-rigid material, for example, ultra-high molecular weight polyethylene (UHMWPE) with a release coating or layer, e.g., a fluoropolymer such as perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE) or expanded PTFE (ePTFE). Other hard plastics or resins that may be used include melamine, fiberglass, acrylonitrile butadiene styrene (ABS) or polyvinyl chloride (PVC). In other variations, the rigid liner may be a composite structure comprising a flexible liner with a rigid frame or rigid struts, which may comprise, for example, a metal (e.g. stainless steel), or a hard plastic/resin.

Once the dressing2310is strained and the dressing assembly2308may be secured in engagement with the support structure2330, the dressing assembly2308and support structure2330may be separated from the tensioning device2341to form the pre-strained assembly2351that may be used immediately or stored for a period of time.

The pre-strained assembly release2352may comprise a tear strip2353that is attached to the tensioning sheet2307between the middle location2373and the second side2374with upper and lower portions2354,2355respectively (SeeFIG.23E). The tear strip2353may act to separate the pre-strained assembly2351from the tensioning device2341by tearing across the tensioning sheet2307between the pre-strained assembly2351and the tensioning device2341.

In use, after the liner2350is released, the dressing2310may be applied to a desired location on a subject's skin. The user may apply pressure to the back side2333of the support2330to activate the adhesive on the dressing2310and/or to apply compression to a wound. Once applied to a subject, the dressing2310may be released from the support2330using the release mechanism2319.

The release mechanism2319may comprise tear strips2309. The tear strips2309of the release mechanism2319may each extend proud of the end2366of elastic sheet2360. The tear strips2309may each be coupled to the dressing assembly2308. A tear strip2309may be coupled to the attachment sheet2304of the dressing assembly308in a manner that defines tear path2362along which the tear strip2309is pulled to separate the dressing2310from the support2330. A tear strip2309may be coupled to the tensioning sheet2307of the dressing assembly2308in a manner that defines tear path2362along which the tear strip2309is pulled to separate the dressing2310from the support2330. Each tear strip2309may comprise a top section2347and bottom section2348. The bottom sections2348may be unattached or free from the support2330as illustrated. The top sections2347of each tear strip2309may be adjacent but unattached to the dressing2310. The tensioning sheet2307and attachment sheet2304may be manufactured to be tearable along the material length while providing tensile strength in other directions, in particular in the tensioning direction of the material of the tensioning sheet2307(direction in which dressing is tensioned, stressed or strained) An example of such material is an LDPE polymer which is produced by an extrusion process that creates a directionally biased grain whereby the material is tearable with the direction of the grain, but has a relative resistance to tearing in the direction transverse to the grain. Notches may be made in the tensioning sheet2307and attachment sheet2304that facilitate tearing along paths2362. The tensioning sheet2307and attachment sheet2304may additionally or alternatively comprise a material such as a low-density polyethylene (LDPE) with perforations formed along tear lines2362.

The dressing2310may be released from the support2330by pulling the tear strips2309to draw the tear strips across paths2362of the tensioning sheet2307and attachment sheet2304. Sections2365and2375respectively of the tensioning sheet2307and attachment sheet2304may remain on the back side2311of the elastic sheet2360. The sections2385,2395respectively, of the attachment sheet2304and tear sheet2307bonded to the tear strips2309may thereby be separated from the tensioning sheet2307and attachment sheet2304. The sections2365and2375respectively of the tensioning sheet2307and attachment sheet2304that are attached to the dressing2310may thereby be separated from the remainder of the tensioning sheet2307and attachment sheet2304that are attached to the support structure2330at its ends2305and2306. Thus, the dressing2310may be released from the remainder of the support structure2330.

The dressing2310may have unattached portions or edges2315at its sides2305,2306where the elastic sheet2360is free from the tensioning sheet2307and attachment sheets2304respectively. Accordingly, the dressing2310may be unstrained at unattached portions2315. Unattached sections2315of the elastic dressing2310may be unstrained and may be free from the adhesive of the adhesive layer340(or may have a reduced amount of adhesive thereon). Thus less stress may occur at the unattached sides or edges defined by sections2315.

In use, the adhesive liner2350may be removed and the dressing2310applied to the surface of a subject's skin. Tear strips2309on each side of the dressing at tear lines may be pulled to separate the dressing2310from the support structure2330, attachment sheet2304and tensioning sheet2307, after the dressing is applied to the surface of skin of a subject. When the support structure2330, attachment sheet2304and tensioning sheet2307are removed from the dressing2310, the stress or strain of the dressing2310may apply a (tangential) compressive force to the skin to thereby treat the skin.

Referring toFIG.24, a plurality of strained dressings2410may be strained in a manner similar to dressing2310and then may each be attached to a first surface2460of single support2430which is rolled and stored in a rolled configuration for dispensing as shown inFIG.24. The strained dressings2410may be coupled to the first surface2460of the single support2430by an adhesive, such as, e.g., a high tack/low peel PSA, which maintains the dressings2410in a strained configuration. Liners2450may be placed on a second and opposite side2470of the support2430and are positioned so that when the support2430is rolled, they are over a skin adhesive on the top of the dressings2410. The adhesive liner2450may also help minimize creep properties of the strained dressings2410. The support2430may be rolled to store the dressings2410. When the support2430is unrolled, the adhesive liner2450positioned on the second side2470and opposing a dressing2410may release from the dressing2410. Dressings2410may be separated by a perforation2480so that they may be individually used.

In some variations, the dressing may be used for the treatment of chronic injection sites or catheter sites that are required for a variety of conditions, including but not limited diabetes, cancer, immune disorders such as severe combined immunodeficiency disease, and the like. It is hypothesized that treatment of skin injection/infusion sites may not only reduce the development of scar tissue or other hyperproliferative disorders associated with frequent injections or chronic infusions, but may have other mechanical effects on pharmacokinetics, that may improve drug dispersion in the tissue, reduce drug leakage, increase the depth of effect, reduce pain at the injection/infusion site, reduce site infection risk, reduce risk of line/pump occlusion at an infusion site, improve analyte or drug level variability, reduce inflammatory layer thickness or depth, reduce dosing level. For diabetes patients, the skin treatment may result in fewer glycemic excursions, improved time-in-range as measured by multiple daily fingerstick or continuous glucose monitoring (CGM), increased insulin bolus volume and/or area in the subcutaneous tissue.

In some examples, the dressing, and optionally one or more structures of the dressing support structure, may comprise one or more openings that may facilitate the use of the strained dressing with an indwelling catheter, cannula or sensor that is inserted into the tissue. In other examples, the device used with the dressing may be transiently inserted through the dressing, e.g. a needle for a blood draw, or needle biopsy tool.FIG.30Adepict one embodiment of the strained dressing3000with an opening3002that has been applied to a target site3004and released from its applicator (not shown) to transfer stress from the dressing3000to de-tension the treatment site3004. An indwelling device, such as an infusion set for an insulin pump system or an indwelling sensor system, may then be placed through the access aperture3002and into the skin or subcutaneous tissue at the treatment site. In this particular example depicted inFIGS.30B to30D, an infusion set3006for use with a medication pump comprises a housing3008, connector tubing3010, a support layer3012for an adhesive layer, and a needle3014. In this particular embodiment, the needle has an acute angle orientation relative to the plane of the support layer3012, but in other examples, the needle may have an orthogonal orientation, or may be in the same plane or otherwise parallel to the plane of the housing or support layer. The needle length may or may not extend beyond the peripheral boundaries of the housing or support layer. The needle sheath (not shown) and/or adhesive protection layer (not shown) of the infusion set3006is removed. The needle3014is then aligned with the opening3002, as shown inFIG.30B, until the needle3014is fully inserted into the target site3004and the adhesive of the support layer3012is adhered to the dressing3000and/or target site3004. In some further variations, a protective dressing may be partially or completed applied over the strained dressing and infusion set. In some variations, the direction of strain in the dressing may be parallel or preferably transverse to the direction of the needle insertion into the target site, or parallel or preferably transverse to the length of the dressing.

In addition to the manual insertion of the needle of an infusion set or indwelling device through an aperture of the dressing, in some variations, the infusion set or indwelling device may comprise a delivery tool or system to facilitate the insertion or placement of the infusion set or indwelling device. The delivery tool may be easier or otherwise require less dexterity to grip than the smaller infusion set, or may hide the delivery needle from the user and/or may automatically insert and/or withdraw the delivery needle during the insertion procedure, which may improve compliance or other aspects of the user experience. InFIGS.31A to31C, for example, the dressing3000with aperture3002may be placed at the target site3004, but where the infusion set3020comprises an exposed orthogonal needle3022is releasably coupled to a larger delivery device or device3024. The delivery device3024and/or needle3022is aligned with the dressing3000and/or aperture3002, as shown inFIG.31A, and then place against the dressing3000, as shown inFIG.31B. The actuator3026on the device3024is then activated to separate the pod3024from the infusion set3020. In this particular embodiment, the infusion set3020does not have an adhesive support layer that extends beyond the peripheral boundary of the infusion set housing3021. Instead, the adhesive may be provided directly on the inferior surface of the housing3021, with or without any support layer therebetween.FIGS.31D and31Eare cross-sectional views depicting the actuation mechanism of the delivery device3024and the detachment of the delivery device3024from the infusion housing3021. The infusion housing3021may be mechanically attached to the delivery device3024by friction and/or by one or more mechanical interlocks3030. To release the infusion device3020, the actuator3026is depressed and plunger tip3032engages catch lever3034to release infusion housing3021. The actuator3026and the plunger tip3032are maintained in the non-engaged position by a spring3036. In another variation, the infusion housing may be releasably attached using an adhesive such as a gel that temporarily adheres the plunger tip to the superior surface of the infusion housing.

Although the exemplary dressings above comprise a single circular aperture that is centrally located, in other examples, the apertures may have other shapes, sizes and/or eccentric locations, and may comprise other markings or indicia. The markings or indicia may be used to differentiate between different openings, and/or to facilitate alignment of the dressing with the target location and/or inserted device. Some variations may also include more than one aperture, e.g. two, three, four, five or more apertures. In still other examples, a dressing may be provided without an aperture, and the needle of the infusion set, syringe or insertion device is used to pierce the dressing and then inserted through the skin or tissue.

FIG.32Adepicts the exemplary embodiment of the dressing3000inFIGS.30A to31C. The dressing3000comprises an oblong shape with rounded corners and a centrally located circular opening3002. The opening3002may have a diameter of about 0.10″ to 0.30″, or 0.05″ to 0.20″. The dressing3000has a longitudinal length that is greater than its transverse width, but in other examples, the dressing may be radially symmetrical. The length and/or width of the dressing may be in the range of 4 cm to 16 cm, or 2.5 cm to 5 cm, or have a surface area of 9 cm2to 19 cm2, or 46 cm2to 70 cm2.

FIG.32Bdepicts another exemplary embodiment of a dressing3200, comprising multiple openings3202,3204,3206. In this particular embodiment, the openings3202,3204,3206are linearly aligned with each other, and optionally linearly aligned along the central longitudinal axis of the dressing3200, as shown inFIG.32B. Optional indicia3208,3210,3212may be provided to facilitate changing of the insertion location during a single use of the dressing3200.FIG.33depicts dressing3200placed against a skin location.

FIG.32Cdepicts another exemplary embodiment of a dressing3220, comprising multiple openings3222,3224,3226,3228. In this example, one opening3222is centrally located, but the other three openings3224,3226,3228are eccentrically located and no three openings are linearly arranged. In other examples, all of the openings may be eccentrically located. Indicia3230,3232,3234and3236may optionally be provided for each opening3222,3224,3226,3228, along with other optional indicia such as the spiral lines3238, which may be used to indicate relative locations.

Other exemplary dressings may include dressings with one or more opening shapes that are non-circular.FIG.32D, for example, depicts a dressing3240with an oval opening3242, andFIG.32Edepicts a dressing3250with a diamond shaped or parallelogram shaped opening3252.

FIG.34depicts another variation of a dressing3400wherein comprising indicia3404to facilitate identification and/or alignment with the dressing opening3402. In this particular embodiment, the indicia3404are provided in four orthogonal directions from the opening3402. These indicia may be helpful for identifying the location of the opening3402, especially in circumstances where the dressing3400comprises a clear material and wherein the underlying skin may be mottled or has extensive markings from scarring or skin damage, which may make identification of the opening3402more difficult. The indicia may be laser etched or printed onto the dressing surface.FIG.35depicts the placement of a strained dressing3400onto a skin location and then released from its applicator (not shown). Once adhered to the skin location, the indicia3404may be used to facilitate the insertion of a syringe needle3406or other access device, while the strain transferred from the dressing3400may reduce the tissue response from the needle insertion to form scar tissue or to induce lipohypertrophy. Although the indicia3404inFIGS.34and35are in contact or otherwise close proximity to the opening3402, in other examples, the indicia may be providing along the periphery of the dressing, or span the dressing area between the opening and edges of the dressing. This may be useful for aligning larger devices that may obscure the opening of the dressing once positioned over the dressing. Alternatively, the material of dressing3400may be opaque and/or colored to provide contrast with the dressing and the dressing opening3402. In still other examples, a dressing may be provided without an aperture, and the needle of the infusion set, syringe or insertion device is used to pierce the dressing and then inserted through the skin or tissue.

In other examples as depicted inFIG.36, a visual guide tool3600may be optionally provided or used to facilitate alignment of the syringe needle3406with the dressing opening3402. The visual guide tool3600includes peripheral indentations3602or openings that may facilitate alignment of the visual guide tool3600with the peripheral edges of the dressing3400. The dressing3400may also be provided with optional indicia or markings to facilitate alignment with the guide tool indentations3602. By aligning the peripheral edge of the guide tool3600with the peripheral edge of the dressing3400, the opening3402of the dressing3400may then be secondarily aligned with the opening3604of the guide tool3600. The opening3604of the guide tool3600preferably may be smaller than the opening3402of the dressing3400, but in other examples may be larger or the same size. The visual guide tool3600may also include indicia3606around its opening3604, and may or may not comprise an opaque material, which may make it easier to visualize the opening3604. The undersurface of the visual guide tool may comprise an adhesive to facilitate maintaining the position of the tool3600during use. The tool3600may comprise an elongate body with the opening3604at the distal end, with the proximal end used to grasp and manipulate the tool3600during the procedure.

In one exemplary procedure, the user will clean and prepare skin site with isopropyl alcohol wipes or other sterile preparations. The dressing is then strained using an applicator, if the dressing is not a pre-strained dressing, and then placed onto the desired site. The applicator is then removed to transfer the strain to the skin. If a visual guide is not needed, the patient can insert the needle into the orifice in the dressing and administer the infusion. If a visual guide is required, place guide on top of dressing and insert the needle through the visual target and administer the infusion. For where there is a preexisting dressing with multiple openings, subsequent injection can follow a rotational sequence and inject in site #1, followed by #2, followed by #3, etc. In some variations, depending on skin conditions, a dressing may last up to 10 days and injections using the dressing may take place at frequencies of 3 per day. The dressing is removed and replaced with a new dressing at the end of the wear period (average 7-10 days).

FIGS.37A and38Bdepict another example of a visual guide tool3700. In this example, the tool3700comprises an elongate body3702with an enlarged distal end3704and a large distal opening3706. The distal opening3706may be configured with boundary edge3708that permits visualization of the outer edge of the dressing3000, excluding the radially inward projections3710,3712,3714, and3716. These radially inward projections3710,3712,3714, and3716may help to point to the location of the dressing opening3002when the tool opening3706is positioned to surround the dressing3000. Although four projections3710,3712,3714, and3716are depicted inFIGS.37A and37B, in other examples, a different number of projections may be provided and at other locations along the boundary edge3708of the opening3706, and may be different shapes, sizes, and lengths than the four orthogonal projections3710,3712,3714, and3716inFIGS.37A and37B, e.g. the projections may comprise arrowhead shapes.

As depicted inFIGS.38A and38B, in some variations, the projections3710,3712,3714, and3716may be configured to facilitate positioning of a delivery device or pod, such as the delivery device3024fromFIGS.31A to31B. In this example, the lengths of the projections3710,3712,3714, and3716are configured so that the ends3718,3720,3722,3724of the projections3710,3712,3714, and3716are each on contact with or equally spaced from the perimeter edge3028of the delivery device3024when the pod3024is properly aligned with the projections3710,3712,3714, and3716of the tool3700. Thus, the configuration of the radially inward projections3710,3712,3714, and3716may facilitate alignment and positioning of the pod3024during use.

In another variation, depicted inFIGS.39A to39E, the strainable or strained dressing3926may be a pre-strained at the point of manufacture to an infusion set3921or assembly, as depicted inFIGS.39A to39E. The system may optionally include a delivery device3900with a body3904, a lower edge3906and an actuator3908. Releasably attached to the bottom of the body3904is an infusion housing3921of the infusion set3920, and includes a needle3922, connector tubing3924and a tension dressing layer3926that extends beyond the lower edge3906of the delivery device3900and housing3921. The tension dressing layer3926further comprises a skin adhesive on its lower surface, which is removably covered by one or more adhesive protective liners3928. The liners3928may comprise a liner tab3930that extends further from the liner3928to facilitate removal of the liner3928from the adhesive on the tension dressing layer3926. The tension dressing layer3926is maintained in a stressed configuration by a rigid applicator or tension support structure3932that includes one or more pull tabs3934to facilitate the separation of the tension dressing layer3926from the tension support structure3932during use. The pull tabs3934attach the dressing layer3926and support structure3932together, but comprises perforations or adhesives that facilitate separation of the dressing layer3926and support structure3932when the pull tabs3934are pulled away from the device. The tension support structure3932or applicator may be removed from around the infusion housing3921by passing the structure3932over the connector tubing3924, or by tearing the structure3932away from the housing3921.

In one exemplary implantation procedure for the integrated infusion set3920, a skin insertion site is selected and prepared with isopropyl alcohol wipes or other sterile preparation. The protective needle sheath (not shown) is first removed from the needle3922of the integrated infusion set3920as it is engaged to the delivery system3900. Next, the adhesive protective liners3928are removed to expose the adhesive on the inferior surface of the prestrained tension dressing layer3926. In other examples, however, the needle cover may be integrated with a liner, such that removal of the needle sheath concurrently removes the protective liners or vice versa. The delivery system3900and infusion set3920is then positioned at the desired insertion site and the needle is advanced into the skin, either manually or via a needle advancement mechanism. Once inserted, the system3900may be used to push the infusion set3920against the skin or otherwise held in place to facilitate bonding between the adhesive and the skin tissue surrounding the needle3922. The actuator3908on the system3900is then actuated to release the infusion set housing3920so that the delivery system3900may be removed, as depicted inFIG.40A. In other examples, the infusion set3920with integrated dressing may be inserted without the use of the delivery system3900.

Next, the pull tabs3934are removed from the infusion set3920, which allows the strained dressing layer3926to decouple from the tension support structure3932, thereby allowing strained dressing layer3926to transfer its tensile stress to a compressive force acting on the tissue surrounding the needle3922, as shown inFIG.40B. In some variations, the tension support structure3932may be left in place after the pull tabs are removed, but in other examples, the tension support structure3932may be removed, to decrease the bulk and/or rigidity of the indwelling infusion set3920. In some variations, the tension support structure3932may be removed by passing the tension support structure3932over the connector tubing3924, as depicted inFIG.40C, if the connector tubing3924is not yet coupled to the infusion pump, leaving the infusion set3920with the dressing layer3926transferring compression to the underlying skin tissue, as shown inFIG.40D. In other variations, as depicted inFIG.40E, the tension support structure3932may comprise a slit or perforations3940, which may allow the tension support structure3932to be pulled away or torn away, from the infusion set housing3921or the connector tubing3924, whether the connector tubing3924has been attached or not. The infusion set3920is ready for use, and may be removed and a new infusion set may be placed at the end of the use period, which may be in the range of 7 to 10 days, but may be replaced earlier if occluded or damaged.

In some other examples, rather than visual indicia or markings, one or more physical alignment structures may be provided on the dressing to facilitate alignment. InFIGS.49A to49E, a pre-strained elastic member or dressing4900with a pre-attached removable alignment structure4902is provided that is configured to align an infusion set with access opening4926of the dressing4900. This alignment structure4902is configured for use with the MINIMED™ QUICK-SERTER™ (Medtronic, Fridley, Minn.) infusion set applicator4904, but one of skill in the art understands that the alignment structure may be tailored to the shape and function of any other infusion set applicator or delivery device. The pre-strained dressing4900is maintained in a pre-strained configuration by semi-rigid or rigid strain support4906attached or adhered to the top surface of the dressing4900, and surrounding the alignment structure4902. The strain support may be configured to have some flexibility in at least one direction in order to contour the dressing to the tissue surface. In some variations, the direction of flexibility may be orthogonal to the direction of strain of the dressing. The shear bond strength between the strain support and the strained elastic member is greater than the force produced by the straining of the elastic member. The attachment of the support4906to the dressing4900may be achieved with an adhesive, or may be heat staked to the dressing4900, depending on the materials selected for the dressing4900. For example, if a polyurethane is used for the dressing4900, the support4906may comprise PETG and can be heat staked to the dressing4900. For example, a heat stake may be used to bond the strained elastic member to the strain support. The heat stake may have a width of about 1 mm, 2 mm or 5 mm, for example. The bond provides adequate shear force without creep in the direction of strain while also allowing the support structure to be peeled away from the elastic member. The strain support may also comprise perforations to facilitate the splitting of the strain support and its separation and removal from the elastic member, and optionally tabs to facilitate grasping and tearing of the perforations. Alternate embodiments of the device may also include the perforations and pull tabs separation mechanism as described for dressing3926inFIGS.39A to39Emay also be adapted to this embodiment.

This particular alignment structure4902comprises a unibody structure with three interconnected alignment flanges4908,4910,4912along a base4914and base opening4916. The opening4916is sized and shaped to form a mechanical interfit with the applicator4904, and may be oval, circular, polygonal or other custom shape complementary to the perimeter of the applicator4904. The base4914may also comprise a lip to increase the surface of area of attachment to the dressing4900. Although interconnected along the base4914, in other examples, the flanges may be separate from each other. In some further examples, the flanges4908,4910,4912and/or base4914may be integrally formed with eat strain support4906. In still other examples, the alignment structure4902may be provided separately and is attached to the strain support4906at the point-of-use. The alignment structure4902may also be selected from a plurality of different alignment structures, each configured for use with a different available infusion set applicator. The selected alignment structure is then attached to the strain support prior to use.

The attachment of the alignment structure4902may vary depending on the material used for the structure4902and the rigid support4906. The alignment flanges4910and4912are configured to provide a recess4918accommodate the infusion set tubing4920, and one or more of the alignment flanges4908may comprise a gripping structures to facilitate handling of the dressing4900, such as finger grips, recesses or ridges4922. The alignment flanges4910and4912may be further configured to be pulled apart to facilitate removal of the alignment structure4902from the tubing4920. After or concomitantly with the removal of the alignment structure4902, the strain support4906is removed to permit the dressing4900to contract from the strained configuration to its less strained configuration. In this particular configuration of the alignment structure4902, the height of the flanges4908,4910,4912may be in the range of about 1-10 mm, 2-8 mm, or 3-6 mm, for example. The inner surfaces of the flanges4908,4910,4912may be comprise an orthogonal orientation or may comprise a slight obtuse angle, e.g. 91-95 degrees, 91-100 degrees or 91-105 degrees, so that the initial placement of the applicator4904itself does not require precise alignment but guides the applicator4904to a more precise location with further insertion. The spacing of the flanges4908,4910and4912, in addition to accommodating the tubing4920, may also be configured to provide access to the sides of the applicator4904, which may also have finger grips4936, so that the actuator4924of the applicator4904is not used to position the applicator4904.

The shape of the dressing4900may be any of a variety of shapes, including but not limited to an oval, circular or polygonal shape. Likewise, the access opening4926may also comprise an oval, circular or polygonal shape, and sized to accommodate the catheter of the infusion set. The access opening4926may comprise a diameter or transverse dimension in the range of 1-20 mm, 2-10 mm, or 3-5 mm, for example. The alignment structure4902may comprise a polymeric material that may be thermoformed or injection molded, 3D printed or CNC machined.

The skin adhesive on the dressing configured to attach to the skin or tissue may be the same or different adhesive used to attach the strain support to the dressing. In some examples, the skin adhesive may be selected with a greater T-peel force than the adhesive used to attach the support. In other examples, the adhesive used to attach the support may have a higher T-peel force. A higher T-peel force may be selected where the predetermined strain in the dressing is needed to resist strain loss during storage of a pre-strained device. A protective or adhesive release sheet may be applied to the skin adhesive to protect the skin adhesive against unintentional adhesion during storage or application. Coatings on the release sheet and the dressing may also be provided to facilitate peeling or removal of the release sheet and the strain support during use.

Referring toFIG.50A, the dressing4900and alignment structure4902is applied and adhered to the selected target site. The adhesive liner of the infusion set held by the applicator4904is removed and the applicator4904is aligned with alignment structure4902, with the tubing4920and the finger grips4922of the infusion correctly oriented to the recesses. The applicator4904is then inserted into the opening of the alignment structure4902until it is fully seated, as illustrated inFIG.50B. In some variations, visual indicia on the alignment structure4902, tactile feedback may be provided to confirm to the user that the applicator4904is fully seated. InFIG.50C, the actuator4924of the applicator4904is depressed to insert the needle/cannula of the infusion set through the opening of the dressing4900and into the skin. The actuator4924is then activated a second time to decouple the applicator from the infusion set hub4938. In this particular example, the actuator4924comprises an outer annular button4930and an inner button4932to separately deploy the needle/cannula and to decouple but not yet separate the applicator4904.

Next, the alignment structure4902and the dressing support4906are removed from the dressing4900by applying downward pressure on the released applicator4904as the alignment structure4902and support4906are pulled away. To facilitate their removal, the support4906may comprise a perforation4934that can be torn so that the alignment structure4902and support4906may be peeled or pulled off, so that the dressing4900can contract from its strained configuration, In other variations, as shown inFIG.51, the support5100of the alignment structure5102may comprise an arcuate configuration with a tabbed end5104that may be grasped and used to pull out the support5100and alignment structure5102from the periphery of the applicator5106and the tubing5108. This then separates the infusion hub4938from the applicator4904, and the rigid support4906from the dressing4902, which allows the dressing4902to contract from its pre-strained configuration.

FIGS.48A to48Edepict example of an infusion system4800with a delivery device4802that releasably holds an infusion hub4804with a pre-attached radially pre-strained skin tensioning device4806. The delivery device4802comprises a body4808and actuator4810, similar to the delivery system3900inFIG.39A. The pre-attached radially pre-strained skin tensioning device4806comprise a radially outward strained adhesive elastic layer4812that is maintained in the pre-strained state by a semi-rigid strain support4814a,4814bthat may comprise a semi-rigid or rigid card stock or polymer layer that is adhered to the top surface of the elastic layer. Although this particular embodiment comprises a strain support with two sections4814aand4814b, in other examples, a single support may be provided, or a 3, 4 or 5 part support may be provided.

After the infusion system4800is applied to the desired anatomical location, and the actuator4810is activated, the infusion hub4804is released and can be separated from the delivery body4808, leaving the infusion hub4804and skin tensioning device4806attached to the anatomical location, as illustrated inFIG.48E. The function and patency of the infusion tubing4816, hub4804and catheter4818may be checked. If functioning correctly, the strain support4814aand4814bmay be removed or separated from the elastic layer4812, which will then radially compress the adhered skin or tissue toward the center of the elastic layer4812around the hub4804and catheter4818. The function and patency of the infusion tubing4816, hub4804and catheter4818is then rechecked before initiating therapy. In some variations, a radially strained skin tensioning device may reduce the risk or rate of kinking or occlusion of the catheter4818in comparison to skin tensioning devices strain along a single strain axis. The shape of the elastic layer4812may be circular as depicted inFIGS.48A to48E, but in other examples, the elastic layer may be oval, oblong, square, rectangular, star or other shape. An oval or oblong shape may be used when the catheter is not orthogonally inserted into the tissue, but rather inserted along an acute angle to the treatment site, where the forces acting on the catheter or infusion hub may not be radially symmetrical.

In addition to a radially strained infusion system4800, a radially pre-strained skin tensioning device5500may be provided for use with manual injection with a syringe5502, as shown inFIGS.55A and55B. The skin tensioning device5500comprises an elastic layer5504with an access opening5506. The skin tensioning device5500may be adhered to the target location and then the radial strain supports5508a,5508bmay be removed to permit the elastic layer5504to radially compress the underlying skin toward the access opening5506. The access opening may comprise a diameter or transverse dimension in the range of 1-20 mm, 2-10 mm, or 3-5 mm, for example.

Referring toFIGS.56A and56B, in some other variations of a skin tensioning device5600, whether radially strained or single-axis strained, the access opening5602of the device may comprise a fabric patch5604. The patch5604may be configured with a woven fabric that permits the needle5606of the syringe5608to still pass through the access opening5602while providing some physical coverage of the injection site. The increased breathability may extend to use time of the device5600. The fabric patch5604may provide increased water vapor transfer across the skin tensioning device5600and may also be used to absorb an excess insulin that may leak from the injection site. The fabric patch5604may be coated, infused or woven with an anti-infective agent, such as an antibiotic or silver strands. The fabric5608may comprise a nylon, non-woven cotton, polyester or polypropylene, an elastic polymer blend, or silver alginate, for example.

In still another alternative embodiment, a skin treatment system5400comprising a tension off-loading dressing5402but instead of an access opening or fabric patch, an injection port5404is provided on the dressing5402, as shown inFIGS.54A and54B. The dressing5402and port5404may be provided with any of the applicators as described herein, noting that the region of the dressing5402attached to the port5404will not under the same strain as the portion of the dressing5402peripheral to the port5404. The injection port5404includes a catheter5406such that syringes attached to the port5402or syringe needles inserted into the port are able to deliver therapeutic agents through the catheter5406and into the skin or tissue. Use of the port may reduce pain or discomfort associated with therapy, compared to direct needle injection.

Referring toFIGS.41A to43C, in another embodiment, an infusion set4100and a multi-layer tensioned dressing4102may be used for subcutaneous infusion or intravascular infusion. The infusion set4100comprises an infusion tubing4104that is connectable to an infusion source or pump, such as an insulin pump or other therapy pump, and is in fluid communication with an internal cavity of an infusion housing4104which is in turn in fluid communication with a subcutaneous needle or catheter4106which is inserted into the tissue or vasculature. The bottom surface of the infusion housing4104is adhered or attached to the top layer4108aof the multi-layer tensioned dressing4102. Each of layers4108ato4108ccomprises a perimeter4110ato4110cthat is sized to be smaller in size and is positioned within and offset from the perimeter4110bto4110dof the layer4108bto4108dimmediately below it, except for an optional flap4112ato4112c. The elasticity of the top and intermediate layers4108a,4108b,4108cmay be configured to be lower than the modulus of elasticity of the base elastic layer4108d. The base layer4108dmay also have a higher durometer (e.g. 60 Shore A vs. 50 Shore A vs. 30 Shore A) or comprise a thicker material (e.g. 10 mil vs. 7 mil vs. 5 mill vs. 0.5 mil) compared to the other layers4108a-c. In other variations, the non-base layers may comprise holes or perforations to reduce the total cross-sectional area of the non-base layer, which can reduce the amount of strain contributed from the non-base layers. With this configuration, the compressive force per unit width results primarily from the contribution of the base elastic layer4108d, about 50%, 60%, 75%, 90% or any range between any two of these contribution percentages. Based on this, the amount of adhesion strength between the layers may be relatively lower than the bond strength between the skin and the base layer4108d. The adhesive of layers4108ato4108c, may also be pattern coated onto the layers4108ato4108cto facilitate peeling in a direction orthogonal to the strain. For example, multiple narrow strips of adhesive may be provided in the direction of the peel. The width of the adhesive orthogonal to the direction of the strain in the elastic member may be 0.1″, 0.165″, 0.2″, 0.3″ or 0.5″ or any range between any two of such widths. In another examples, an adhesive pattern may be provided where less adhesive is peel direction as compared to the strain direction, e.g. 20% less, 40% less, 60% less, 80% less, or a range between any two of these percentages, or other type of anisotropic adhesive pattern. The interlayer adhesives used to join all of the layers4108a-dtogether may comprise a lower thickness compared to the skin adhesive (e.g. 0.5 mil, vs. 0.25 mil, vs. 0.1 mil). In other variations, an adhesive with a high-tensile strength but low shear strength may be used, to facilitate removal of an upper layer of the multi-layer tensioned dressing by pulling the layer or adhesive layer laterally rather than upward. This nested configuration results in a stepped dressing profile, as depicted inFIGS.44A and44B, which may redistribute edge stresses of a skin tensioning device across a greater surface area, rather than concentrate them at the edge of a single layer skin tensioning device. In some variations, the separation between the perimeters4110ato4110dof adjacent layers4108ato4108dmay be uniform along the entire perimeter, e.g. a uniform perimeter difference in the range of 1 to 5 mm, 2 to 5 mm, or 2 to 4 mm, or 2 to 3 mm, for example. In some further examples, the uniform perimeter difference between two adjacent layers4108ato4108dis the same for every two adjacent layers4108ato4108d. In other examples, the uniform perimeter difference may be different between at least one pair of two adjacent layers. For example, the perimeters4110aand4110bmay be the same as4110band4110c, but the uniform perimeter difference between layers4110cand4110dmay be smaller or larger then uniform perimeter difference of the other pairs of layers4108ato4108c. Layer4108dinFIG.41Adoes not have a flap, but in other embodiments may also be provided with a flap. The flaps4112ato4112cmay or may not comprise adhesive on its inferior surface, which may facilitate separation and grasping of the flap4112ato4112cfrom the other layers for removal. Each of the layers4108ato4108dalso comprises a center opening (not shown) through which the needle or catheter4106of the infusion set4100may be inserted. This nested layer configuration of the multi-layer dressing4102may not have a flap The flexible attachment sheet4108is sized and configured with a perimeter4112that is smaller than a perimeter4114of the multi-layer tensioned dressing4102.

Although the exemplary embodiment depicted inFIGS.41A and41Bcomprises a four-layer skin tensioning device4102, in other examples, the skin tensioning device may comprise two, three, five or more layers. The infusion set4100and the skin tensioning device4102may be pre-assembled at the point of manufacture, assembled at the point-of-use, or assembled serially at the treatment site, with the skin tensioning device4102place first, followed by the infusion set4100through and onto the skin tensioning device4102. The applicator for the skin tensioning device4102may be the book-type applicator as described herein. In another variation, the infusion device4100may be pre-attached to one flexible layer of adhesive material larger than the infusion set housing4104and comprises a similar material and adhesive as the layers of the multi-layer skin tensioning device. During use, the skin tensioning device is strained and applied to the skin, but the infusion device4100and its pre-attached flexible layer of material are not strained when applied to the multi-layer skin tensioning device.

As depicted inFIGS.42A to43C, when the infusion set4100needs to be replaced, e.g. due to occlusion or to reduce the risk of infection, the flap4112aof the top layer4108amay be grasped and then lifted up to separate the adhesive of the top layer4108afrom the intermediate layer4108b, or to otherwise peel away the top layer4108afrom the intermediate layer4108b, thereby also lifting up the infusion4100up with the top layer4108a, and pulling out the catheter4106from the skin, while leaving the other layers4108b-dof the multi-layer skin tensioning device on the skin, thereby minimizing the frequency that the adhered skin tensioning device is separate from the skin. This may reduce irritation of the underlying skin from repeated removal of an adhered device. Once the infusion set4100is removed along with the top layer4108a, a new infusion set4100may be applied to directly to the intermediate layer4108b, by aligning the delivery location of the catheter4106of the new infusion set4100with the opening4114bof the intermediate layer4108b. This cycle of removal and reapplication may be performed several times equal to the number of layers in the skin tensioning device, with subsequent cycles of new infusion sets removed and applied to the next layer, with the base layer4108dalso being used and later removed with the final infusion set4100.

Like other embodiments described herein, the skin adhesive on the bottom layer of the skin tensioning device may be the same or different adhesive used to attach the strain support to the dressing, and/or the adhesive used to attach the multiple layers of the skin tensioning device together. In some examples, the skin adhesive may be selected with a greater T-peel force than the adhesive used to attach the support. In other examples, the adhesive used to attach the support may have a higher T-peel force. A higher T-peel force may be selected where the predetermined strain in the dressing is needed to resist strain loss during storage of a pre-strained device. A protective or adhesive release sheet may be applied to the skin adhesive to protect the skin adhesive against unintentional adhesion during storage or application. Coatings on the release sheet, and layers of the dressing may also be provided to facilitate peeling or removal of the release sheet, the layers, and the strain support during use. The strain support for this embodiment may include the perforation and pull tab separation mechanism (not shown) as described for dressing3926inFIG.39A, to releasably maintain the strain with at least layer4108d, but may also be configured to directly releasably maintain strain in the other layers4108a-cas well.

FIGS.45A and45Bdepict another example of an infusion set4500with a multi-layer dressing4502pre-attached to an infusion hub4504, tubing4506and catheter4508, but in this variation, the lower layers4510b-dare smaller than the adjacent upper layers4510a-c. This configuration is also a stepped dressing profile, which may redistribute edge stresses of a skin tensioning device across a greater surface area, rather than concentrate them at the edge of a single layer skin tensioning device. The base layer4510d, however, has a smaller adhered surface area, and the upper layers4510a-care only adhered to the skin about their periphery. Like the embodiment depicted inFIGS.41A to44B, the separation between the perimeters4512ato4512dof adjacent layers4512ato4512dmay be uniform along the entire perimeter, e.g. a uniform perimeter difference in the range of 1 to 5 mm, 2 to 5 mm, or 2 to 4 mm, or 2 to 3 mm, for example. The uniform perimeter difference between two adjacent layers4510a4510bmay be the same for each two adjacent layers4510ato4510d, or may be different. In other examples, the uniform perimeter difference may be different between at least one pair of two adjacent layers. The layers4510a-dmay also comprise optional flaps4514a-c, to facilitate grasping and removal of the layers4510a-c. The other features of the device may otherwise be similar to the four-layer skin tensioning device4102inFIGS.41A and41B, e.g. the heat staking and adhesive configurations.

As depicted inFIGS.46A to47C, when the infusion set4500needs to be replaced, e.g. due to occlusion or to reduce the risk of infection, the flap4514aof the top layer4510amay be grasped and then lifted up to separate the adhesive of the top layer4510afrom the intermediate layer4510b, or to otherwise peel away the top layer4510afrom the intermediate layer4510b, thereby also lifting up the infusion hub4504up with the top layer4108a, and pulling out the catheter4108out of the skin, while leaving the other layers4510b-dof the multi-layer skin tensioning device4502on the skin. This minimizes the frequency that the adhered skin tensioning device4502is pulled off of the skin. This may reduce irritation of the underlying skin from repeated removal of an adhered device4502. Once the infusion hub4504is removed along with the top layer4510a, a new infusion set4500may be applied to directly to the intermediate layer4510b, by aligning the delivery location of the catheter4508of the new infusion set4500with the opening4516of the intermediate layer4510b. This cycle of removal and reapplication may be performed several times equal to the number of layers in the skin tensioning device, with subsequent cycles of new infusion sets removed and applied to the next layer, with the base layer4510dalso being used and later removed with the final infusion set4100. The strain support for this embodiment may include the perforation and pull tab separation mechanism (not shown) as described for dressing3926inFIG.39A, to releasably maintain the strain with at least layer4510d, but may also be configured to directly releasably maintain strain in the other layers4510a-cas well.

In another embodiment, a skin tensioning system for treating a therapy injection or infusion site may comprise a pair of tension dressings5200and5202, as depicted inFIG.52. Each of the dressings5200and502may be provided a dressing tension applicator (not shown) as described herein, e.g. book applicator. The dressings5200,5202may have separate applicators, but in some embodiments, may be provided on the same applicator with a predetermined spacing or gap5204between the dressings5200,5202as configured in the applicator. During use, or as supplied in the applicator, the gap5204may be in the range of about 1-20 mm, 2-10 mm, 3-8 mm, 4-6 mm, for example. Each of the dressings5200,5202are tensioned along a tensioning axis5206,5208, if the dressings were not pretensioned at the point-of-manufacture. The applicator may also comprise visual alignment indicia so that any prespecified spacing or gap5204between the dressings5200,5202may be aligned or oriented as needed to a particular injection or infusion site. Each of the dressings5200,5202are placed adjacent to the desired injection or infusion site5210, on opposite sides of the target site5210. Each dressing5200,5202may comprise a treatment edge5212,5214that are aligned in a parallel fashion to define the gap5204between the dressings5200,5202. The gap5204on the skin or on the applicator may be characterized by a longitudinal gap axis5216, which may also be parallel to the tension axes5206,5208of the corresponding dressings5200,5202. After each dressing5200,5202is positioned about the target site5210, the applicator or strain support for each is released, allowing the dressings5200,5202to at least partially relax and compress the skin surrounding the target site5210. This resulting skin compression is generated at the target site5210without any dressing completely surrounding or covering the target site5210, although support of skin tension orthogonal to the tensioning axes5206,5208and gap axis5216is reduced because the two dressings5206,5208are completely separate along that direction.

In still another embodiment, a skin tensioning dressing5300for treating a therapy injection or infusion site may comprise a pair of tension lobes or sections5302and5304, as depicted inFIG.53. Each of the sections5302and5304are integrally formed with an interconnect or bridge5306and a separated by a section gap5308. The gap5308may be in the range of about 1-20 mm, 2-10 mm, 3-8 mm, 4-6 mm, for example. The dressing5300may be provided with an applicator as described elsewhere herein. Each of the dressing section5302,5304are tensioned along a tensioning axes5310,5312. The applicator may also comprise visual alignment indicia so that the gap5308may be aligned or oriented as needed to a particular injection or infusion site. Each of the dressing sections5302,5304are positioned with the target site is in the gap5308. After the dressing5300is located and adhered to the desired target site, the applicator or strain support is released, allowing the dressing sections5302,5304to at least partially relax and compress the skin surrounding the target site.

Any of the skin tension off-loading devices corresponding toFIGS.30A to56Bmay be evaluated with proposed study designs to evaluate the effects of skin tension offloading on insulin pharmacokinetics, dosing, therapeutic efficacy, and/or the development of lipohypertrophy are described below, including potential health economic benefits. Diabetes patients currently treated with insulin will be randomized to a treatment group or control group, with treatment comprising use of the skin tension offloading devices selected from those corresponding toFIGS.30A to56Bmay be used for 4 weeks to 5 years or more, 4 weeks to 2 years, 8 weeks to 1 year as described herein. The dressings or skin tension offloading devices, or a layer and/or infusion set may be changed every three days, or every 2 to 14 days, 3 to 10 days, 10 to 14 days, 5 to 7 days, 3 to 5 days, 2 to 3 days for the selected study period.

In one proposed study evaluating the effects of one or more of the tension offloading devices will be evaluated in insulin-dependent patients with preexisting lipohypertrophy mass, to assess whether the tension offloading devices can alter the pharmacokinetics or delivery kinetics of insulin to patients who inject or infusion insulin or an insulin analogue to a site with pre-existing lipohypertrophy. Diabetes patients will be screened for lipohypertrophy masses in the range of 6-10 cm and then randomized to have a tension offloading device applied during the study. Each patient will be randomized to a test day where they will each undergo two glucose absorption tests after an overnight fast, where the tests are separated by a minimum of 7 days and an overnight fast before the tests. An indwelling catheter will be placed for each patient to provide blood samples for blood glucose and insulin levels during the test period. Baseline levels are measured and then each patient will receive a subcutaneous injection of 10 units of insulin through the access opening of the skin tension offloading device in the treatment group, or directly to the skin location in the control group. Blood samples will be obtained every five minutes for the first thirty minutes, then every ten minutes for the next 60 minutes, then every 30 minutes for the next 2.5 hours. The maximum concentration of plasma insulin at each time period will be determined as well as the time to maximum insulin concentration, and the area under the insulin concentration curve will be analyzed to assess any direct effect of the skin offloading device on insulin absorption.

In another proposed study, patients will be randomized to receive skin offloading treatment kits in conjunction with insulin or insulin analogue injection or infusion, for use over a treatment period of 4 weeks, 6 weeks, 8 weeks, 3 months, 4 months, 6 months 9 months, 12 months, 18 months or 24 months, for example. The tension off-loading treatments will be used as directed with replacement of the device, or change in a layer of a multi-layer device, every 2 days, 3 days, 4 days or 5 days, or as needed. Blood glucose will be measured at least 4 times per day, and compliance with blood glucose measurements and use of tension offloading devices will be assessed. The analysis will be an intent-to treat analysis and the mean amplitude of glucose excursion will be calculated over the treatment period and the postprandial area under the curve will be calculated for each mealtime over the treatment period. Alternatively or in addition, hemoglobin A1C will be measured at baseline and at each follow-up to assess the effects of the skin tension offloading device. A health economic study and/or a patient quality-of-life study may also be included in the analysis.

Patient inclusion criteria may include one or more of the following:Patients with or without prior history of lipohyperdystrophyPatients with a lipohypertrophy mass in the range 5-10 cmPatients with high daily insulin dose requirements of a least 0.9 UI per KgPatients with minimum insulin use of 50 IU/dayTreatment with insulin or insulin analogue for at least one year prior to enrollmentPrior experience with rapid-acting insulin analog for at least 6 monthsType I or Type II diabetic patientsTreatment is self-administered or given by a caregiverCurrent treatment includes at least two to four injections per day, or insulin pump useBody Mass Index in the range of 20 to 35 kg/m2.Stable body weight for 3 months prior to enrollment (≤5% change in body weight)Hemoglobin A1C≤8.5%C-peptide <0.6 nmol/L at screening

Patient exclusion criteria may include one or more of the following:Pre-existing lipodystrophy or lipohypertrophyChildren under the age of 5 yearsPatient not currently treated with insulin or analogueWomen with gestational diabetesHistory of hypoglycemic unawarenessHistory of diabetic ketoacidosis within 6 months of screeningHistory of cardiovascular diseaseHistory of arrhythmia

The primary and secondary endpoint(s) will assess the development or presence of lipohypertrophy and/or changes in blood glucose or blood glucose variability factors at each visit. The initial assessment and each follow-up visit will include evaluation of:Serial ultrasound scans using a linear 20 MHz probe using B-mode imaging:Classification:Simple subcutaneous hypertrophyDiffuse hyperechoic subcutaneous dystrophyNodular hyperechoic dystrophyFocal and diffuse hyperechoic subcutaneous dystrophyNodular hypoechoic subcutaneous dystrophySubcutaneous atrophyComplex multilayer dystrophyFibrosis levelIso-hyperechogenicIsoechogenicIso-hypoechogenicDirect and tangential light inspection and color photography of the treatment site, against a dark backgroundClassification of the treatment site as to shape and size using palpation and skin calipers:Small nodule—visible on inspection, easy to palpate with an elastic consistencyLarge nodule—clearly visible on inspection, easy to palpate, with a hard to elastic consistencyFlat plate—slightly raised and somewhat visible, difficult to palpate except with skin pinching, with an elastic consistencyFlat nodule—not visible but palpable on deep palpation or skin pinching, with an elastic consistencySize, including <4 cm and >4cmClinical Grading, from zero to 3:0—no changes1—visible hypertrophy but normal consistency on palpation2—substantial thickening and denser consistency3—evidence of lipoatrophyValidated diabetes questionnaires (start and end of study only)Problem Areas in Diabetes QuestionnaireDiabetes Treatment Satisfaction Questionnaire

At the end of the study, the percentage change in prandial insulin and total daily insulin dosing, time-in-range (70-140 mg/dl) and out-of-range (<70 mg/dl and >180 mg/dl) for studies with patients using continuous glucose monitoring devices, hemoglobin A1C, the number of hypoglycemic events, the number of diabetic ketoacidosis events will be calculated and compared between the treatment and control groups. For studies involving patients with CGM or insulin pumps, pain assessments during cannula/infusion set insertion removal, cannula/infusion set malfunction (occlusion, needle deformation), will be assessed and compared.

It is hypothesized that applying a skin tension offloading device in a substantially continuous fashion may reduce the risk, progression or severity of a lipodystrophy, including lipohypertrophy in insulin-dependent patients. By reducing or limited the development of lipohypertrophy, dose progression or therapeutic effect variability relating to lipohypertrophy may be slowed or reduce. It is also hypothesized that some of the effects on dose progression and therapeutic effect variability may be independent of the development or progression of lipohypertrophy, and may be a direct result of the skin tension off-loading device on tissue mechanics and pharmacokinetics. The use of a skin tension offloading device configured with predetermined levels of strain will permit controlled and consistent delivery of strain level and to measure effects of different consistent levels of strain, compared to other skin tensioning devices that are manually adjusted in an ad hoc fashion, as with many sutureless wound closure devices. Initial studies may include patients with preexisting lipohypertrophy and/or high daily insulin dosing requirements, to more easily identify clinical effects. Using the long-term data from the studies, an outcome flowchart will be developed and costs per event will be estimated so that a cost-effectiveness and/or health economic analysis may be performed. In conjunction with patient quality of life measures, a quality-adjusted life-year cost may also be calculated.

While this invention has been particularly shown and described with references to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention. For all of the embodiments described above, the steps of the methods need not be performed sequentially.