Custom patterned wound dressings having patterned fluid flow barriers and methods of manufacturing and using same

A custom fabricated (e.g. custom shaped and dimensioned) wound dressing that matches a corresponding, pre-mapped integumentary wound includes one or more liquid flow barriers composed for example of a hydrophobic and high viscosity liquid embedded in a layer of the dressing. One such embedded hydrophobic liquid barrier covers a skin section immediately adjacent to the wound opening so as to protect the skin section from harmful liquids such as exudates or water. In one embodiment, the skin protecting barrier is substantially comprised of a silicone oil having a viscosity in the range of about 100 cSt to 1000 cSt.

CROSS REFERENCE TO AND INCORPORATION OF CO-OWNED APPLICATION

The following copending U.S. patent application is owned by the owner of the present application, and its disclosure is incorporated herein by reference:

CROSS REFERENCE TO AND INCORPORATION OF PUBLISHED APPLICATIONS AND PATENTS

The disclosures of the following published U.S. patent applications or patents are incorporated herein by reference:

(B) U.S. Pat. Publication No. 2004-0015115 and its underlying source: U.S. Ser. No. 10/431,888 filed May 7, 2003 by Dmitriy Sinyagin, originally entitled, “Method for Treating Wound, Dressing for Use Therewith, and Apparatus and System for Fabricating Dressing”, and claiming priority of and incorporating U.S. Provisional application 60/378,635 filed May 7, 2002; and

FIELD OF DISCLOSURE

The present disclosure of invention relates generally to care and management of wounds to the integumentary systems of humans or other mammals. The disclosure relates more specifically to the fabrication and use of custom tailored wound dressings that are custom patterned to match individual needs of individual wound zones over time on individual patients.

DESCRIPTION OF RELATED TECHNOLOGY

The outer protective system or integument of human and other mammalian bodies is a complex system that is typically comprised of growing, aging and dying or dead skin cells; of oil glands, sweat glands, hair and hair follicles, peripheral blood vessels (capillaries), nerve endings and other components. For land dwelling mammals, the integument serves as a protective interface between delicate internal organs and a generally dry, and often microbe populated (dirty) and abrasive ambient environment which is hostile to delicate internal organs that need to be kept moisturized, fed with oxygenated blood, kept free of harmful microorganisms and kept at healthy body temperatures.

Healthy skin is constantly generating new skin cells (epitheliating cells) and progressively converting these new skin cells into aging, drying and dying cells that push their way outwardly through the epidermis to interface with the generally dry, dirty and abrasive ambient environment. Aside from interfacing with the generally hostile external environment, healthy skin generally performs many other vital functions including that of regulating body temperature (e.g., by sweating), excreting waste products (e.g., salts) and providing sense of touch.

In order to continue to provide these various functions, different levels of the epidermis in the skin require correspondingly different ones of graduated micro-climates and different physiochemical micro-environments. These graduated and differentiated micro-environments range from that of a relatively dry, yet nonetheless oil lubricated one at the outer surface of the epidermis to a relatively wet, fluidic and flowing environment at deeper levels of the integument where the basal epidermis and deeper parts of the integument tend to be populated by blood vessels and growing, dividing cells and the like.

When a skin puncturing wound occurs, these graduated systems of differentiated micro-climates and physiochemical micro-environments are disrupted. Areas of skin that are normally relatively dry may become unduly wet due to flow of liquids (exudates) that discharge from the wound center and move out uncontrollably over drier skin areas. On the other hand, deeper parts of the skin structure that are normally wet and free of harmful microorganisms may become unduly dry and infected with colonized bacteria due to exposure to open air and contaminants.

Conventional wound treatments apply a homogenous wound dressing (e.g., one made of woven cotton threads) over the entire wound area primarily for the purpose of keeping the wound clean, protecting it from external contaminants as well as direct physical trauma and perhaps soaking up some initial bleeding.

More recently, custom tailored wound dressings have been proposed for treating wounds individually and at different stages of their development. More specifically, individual wounds of individual patients are mapped, measured and characterized according to their localized zones. For example, digital images of the wounds, with size calibration are taken in a natural visible light range and/or by other means (e.g., polarized light, IR images, UV images, etc.) and by associating different identifiable areas of the imaged wound with different wound zone characteristics (e.g., overly wet zone, overly dry zone, etc.). Individual or overlapping treatment goals are then assigned to each of differently characterized wound zones. Thereafter corresponding dressing functions are designated for each of the differently characterized wound zones and these dressing functions (e.g., heavy absorption of moisture, blocking of evaporation, etc.) are unified to define a custom tailored dressing that is automatically fabricated for and according to the individual dimensions of the individual wound zones of a given individual patient. The above-cited U.S. patent applications (incorporated herein by reference) disclose various methods for automatically custom designing and custom fabricating individual dressings for individual wounds.

In forming the custom tailored wound dressings, there is one aspect of wound treatment that is often overlooked, namely, the needs of the surrounding skin.

SUMMARY

Protection and/or nourishment of the skin surrounding an integumentary wound are important because that skin is often the source of wound-closing re-growth. If healthy skin adjacent to an open wound is allowed to degrade or deteriorate due to benign neglect, the skin may begin to contribute in its degraded form to the expansion and worsening of the original wound instead of contributing to contraction and healing of the wound.

In accordance with one aspect of the present disclosure, liquid flow blocking barriers are custom designed and integrated into a custom patterned wound dressing so as to block potentially harmful liquids (e.g., wound exudates) from flowing into contact with skin adjacent to a wound; or so as to reduce the amount of, or length of time that such harmful liquids that are allowed to contact the adjacent skin. The potentially harmful liquids may include aqueous exudates that can carry microbes or corrosive, toxic chemicals. They may also include simple water, where prolonged exposure to the latter can degrade healthy skin.

In accordance with one embodiment, a dividing line, or a constraining ring or another dividing pattern is defined at one or more custom picked locations in a wound dressing by pattern wise depositing a hydrophobic liquid onto a laterally extending layer of the wound dressing. The deposited hydrophobic liquid is caused to infiltrate vertically at least partially into the thickness of the lateral dressing layer and to become embedded therein. Viscosity of the embedded hydrophobic liquid relative to the dressing layer that contains it (in other words, resistance of the embedded liquid to further flowing within the dressing layer) is caused to be (or is from the start) sufficiently high after infiltration so that the embedded hydrophobic liquid substantially resists being further displaced from its initial locus of infiltration within the dressing layer. The embedded hydrophobic liquid substantially comprises or essentially consists of a hydrophobic material (one that repels water and/or repels aqueous solutions such as wound exudates) and it thus functions as a barrier to water or aqueous solutions flowing through it from one side of the barrier to an opposed other side. In one embodiment, the hydrophobic liquid is deposited and infiltrated into a skin contacting layer of a dressing so as to define a customized barrier that blocks or substantially inhibits the flow of water, exudates and/or other liquids that may be potentially harmful to skin from contacting a skin area for a prolonged time where the protected skin area is one contacted by the skin contacting layer. As such, wound-adjacent skin is protected from prolonged contact with water, exudates and/or other potentially harmful liquids and is given a better chance to grow and close up the wound.

More specifically, in one embodiment, one or more silicones (polysiloxanes), silicone oils, and/or non-aqueous organic or inorganic solutions thereof (e.g., a solution including a solvent which temporarily reduces the viscosity of the included silicone(s)) is deposited in the form of a custom tailored pattern on areas of a wound dressing layer that are designated to contact healthy skin or peri-wound skin adjacent to a given, pre-mapped wound. The deposited silicone(s), silicone oil(s), or silicone solution(s) is/are formulated to infiltrate at least partially into, if not entirely through the thickness of the skin contacting layer and to thereafter become more firmly embedded in that wound dressing layer. In other words, the deposited and infiltrated silicone(s)/solution(s) and/or the dressing layer into which it/they are infiltrated, is/are formulated so that the deposited hydrophobic liquid(s) substantially retain its/their deposited pattern or shape after having infiltrated partially or fully into the thickness of the corresponding dressing layer. In one embodiment, the corresponding dressing layer substantially comprises or essentially consists of a nonwoven mesh of organic polymer microfibers with a relatively small average pore size. Once a certain volume of infiltrating hydrophobic liquid becomes enmeshed in the microfiber matrix and its infiltration speed slows, surface tension and/or capillary effects take over to prevent the embedded hydrophobic liquid from spreading substantially farther. The partially or fully infiltrated silicone material then defines a custom-patterned and pattern-retaining barrier that blocks or repels the flow of water and/or aqueous solutions (e.g., exudates) through its area of infiltration.

In one embodiment, the infiltrated silicone(s) has/have a viscosity in the range of 1 cSt to 10,000 cSt (CentiStokes). The specific viscosity or viscosities used depends on the porosity and/or other characteristics of the infiltrated wound dressing layer (e.g., the whettability of microfibers in the wound dressing layer by the utilized silicone or silicones) and on the functions that the deposited silicone(s) are asked to perform. For example, not all of the deposited silicones may be designed to retain their original shape for a long time. Some may be intentionally designed to flow into an adjacent, temporarily moisturized area of the wound dressing after the moisture (e.g., water and/or medicine) has been dissipated from that adjacent, temporarily moisturized area. In one embodiment, a silicone oil is used having a viscosity in the range of 100 cSt to 1,000 cSt, or nominally, a viscosity of about 500 cSt.

Silicone is not the only patternable and water-blocking material that may be used to form a custom patterned barrier. A wide variety of other liquids or gels whose viscosity, fluidity and infiltration into a porous layer may be controlled and that are themselves not generally harmful to skin may be used, including various vegetable oils and mineral oils. Silicones (polysiloxanes) are particularly attractive for this function because their viscosities can be custom tailored to match porosities and other attributes of polymer microfiberous sheets and because silicones are generally not harmful to healthy skin. (Of course, if a given patient is allergic to one or more silicones, other materials would have to be used. Automated recognition of patient allergies and adaptive response thereto can be part of the custom design process for fabricating a custom wound dressing matching a given wound and an individual patient.)

Intrinsic silicones tend to be colorless. However, non-toxic colored dyes may be added to them. See for example U.S. Pat. No. 4,737,537 (Colored Silicone Composition) whose disclosure is incorporated herein by reference. In accordance with one aspect of the present disclosure, silicones or other water repellant barrier liquids are colored by adding thereto non-toxic dyes (e.g., not harmful to skin or other tissue) so as to form readily visible boundary lines or curves on the wound facing surface of a wound dressing. The dye color may be selected to contrast strongly with the color of the wound facing surface of a wound dressing and/or with a medicinal addend that is to be added in a region whose boundary is defined by the water repellant barrier liquid(s). For example if the dressing surface is white, the selected dye color may be a dark blue or green. Users may then be instructed to infuse water, saline solution or specific medications into visibly bounded regions on a custom dressing. The colored water repellant barrier liquids may also be used to label the bounded regions that the repellant barrier liquids define such as marking a first region as “i”, a second as “ii” and so forth.

Full circle coordination and control of wound treatment design and of application of a corresponding custom designed wound dressing may be provided by a packaged product formed in accordance with the disclosure under control of a coordinating computer program where the program oversees mapping and characterization of a given wound, automated fabrication of a corresponding wound dressing, and automated packaging of the fabricated dressing into a sterile or clean package having functional routing and/or usage indicia provided thereon for getting the packaged product routed to a correct patient and a matching wound on that patient.

Other aspects of the disclosure will become apparent from the below detailed description.

DETAILED DESCRIPTION

FIG. 1Aschematically represents a combination100of a given human living body101interacting with a potentially hostile external environment102(e.g., air contaminated with harmful microbes, with dirt, toxins, etc. and other surroundings which can inflict trauma on the body). Portion110of the body101represents a hypothetically sectionally removed cube of healthy skin tissue lying adjacent to an open wound site120also belonging to the given human patient101. As seen, the healthy section110comprises a complex assortment of organelles and layers including a relatively dry and dead top portion111(stratum corneum) of the epidermis and a moderately wet, alive and reproducing basal portion115(stratum basal) of the epidermis.

Additionally, healthy and intact section110includes oil glands, hair follicles, hair112, sweat pores113, and a vascular network119positioned deeper within section110. The vascular network119supplies oxygen, water and nutrients to the growing and reproducing cells of the basal portion115of the epidermis. It may be appreciated fromFIG. 1Athat the concentration of water in a healthy skin section such as110typically decreases as a continuum as one rises in the +Z (vertical) direction from the relatively wet environment of intact vascular network layer119, through the epithelizing basal layer115and up to the aged and dry skin cells at the very top111of the epidermis. As is well known in the medical arts, dead skin cells are constantly flaking off in unnoticed quantities from the outermost part111of a healthy epidermis as the body101interacts abrasively with the outside environment102and new cells are constantly being generated by the intact and healthy basal layer115to replace the flaked off dermis.

Referring to the perspective schematic of the adjacent open wound site120inFIG. 1A, it may be seen that once an open wound is created, the moderately moist, normal environment of the intact basal layer115is not present for exposed growing skin cells125that are trying to grow radially inward (in direction126) to close up the wound opening. Instead these inward growth-attempting cells125are exposed to a much dryer and otherwise more hostile environment102adue to the incoming dry air entering through the opening of wound site120. During normal healing, epitheliating cells125grow laterally in a wound closing direction126from the still-intact surrounding skin (127and/or130) towards the center region, R0of the wound. At the same time, deeper vascular tissue (e.g.,119) tries to thrive and grow vertically upward in the +Z direction so as to restore the underlying support structure that nourishes the basal portion115of the epidermis in healthy intact skin (110). These various activities are desirable in order to close up the wound and permit quick healing.

Of course, many different mechanisms may be present to compete against and/or to block the radially inward healing process126attempted by peri-wound tissue (125,127) and/or to thwart the upwardly moving (+Z) growth and restructuring processes attempted by the deeper tissue of the wound site120. For example, the patient101may be afflicted with chronic diabetes, and/or with an impaired immune system, or old age, and/or other medical conditions that prevent normal rapid healing. Aside from that, the open wound120may be exposed to dry and potentially dirty incoming air102aas already mentioned. Secondly, one or more central regions (e.g., R0) of the wound may have been infected by and thus colonized by harmful bacteria where that bacteria is causing damage to the subdermal tissue and impeding healing re-growth or even expanding the size of the wound due to expansion of the infection. Additionally or alternatively, new bacteria may enter the open wound site120from the outside environment102band thus infect it. When infections, external trauma or the like occur, the immune system and other aspects of the body try to go to work and to begin generating protective liquids in the process of fighting off invading microbes and/or filling up the open wound cavity. Some of the generated liquids (exudates) may be harmful to surrounding healthy skin (e.g., to areas121,125,127and130). Exudating liquids may include discharging pus, growing bacteria, and toxic chemicals generated in the exudating wound zone140. If the surrounding healthy skin (121,125,127,130) is harmed, it may not be able to contribute to the healing process (126) or worse yet, the exudated liquids may cause the wound site120to grow even larger.

Every human patient101is different and may have unique wound treatment requirements including that of supplying a clean flow of medications into the wound site. Additionally one patient may have multiple wounds (e.g., sores, ulcers, etc.) of different sizes, shapes and morphologies. Depending on whether certain disease processes are present in different body regions and so forth, each wound site120may have a variety of differently characterized zones and each wound zone may have its own individual shape, topography, dimensions and treatment needs. As such, each wound site may have to be treated individually. By way of example, open wound site120ofFIG. 1Ais shown to have a centrally located, heavily exudating zone140at position R0, and an overly dry, epitheliating wound zone128at first radial position R1. The illustrated wound site120is further shown to have a peri-wound zone127at second radial position R2, and to have further away from the peri-wound zone127, an adjacent and intact healthy skin zone130at third radial position R3. A topmost skin layer121may cover the healthy adjacent skin130and may partially cover the peri-wound zone127and/or epitheliating wound zone128. Peri-wound zone127may be inflamed or otherwise irregular due to the adjacent open wound120. The illustrated wound site120is further shown to have a flexible tape ruler103placed near to it. In one embodiment, a color photograph (e.g., a digitized color image) is taken of the combination of the wound site120and adjacent ruler103so that dimension of various parts of the wound can be determined with reference to the adjacent ruler103. In one embodiment, the adjacent ruler103extends to identifiable landmarks preexisting or added (e.g., marked) on the patient's body so as to thereby create a reproducible frame of reference and the taken image of the wound120and ruler103includes the identifiable landmarks.

Conventional wound dressings attempt to cover the entirety of the open wound site120and slightly beyond with a homogenous dressing material such as woven cotton so as to at least prevent dirt and new bacteria (102b) from entering the open wound. By contrast and more recently, as mentioned above, it has been proposed to map and characterize a wound site such as120according to a variety of parameters including for example, by indicating which areas (zones) of the wound have too much liquid in them (too wet) and which have too little (are too dry) and which have a moisture concentration which is just about right. This characterization of wound zones may be performed by a health care provider (e.g., doctor) with or without assistance from objective automated measurement tools that measure for example, local water concentration, local pH, and so forth. Referring toFIG. 1B, shown is a first wound characterizing plot150that indicates relative degree of excess moisture (in the direction of the +W wetness axis) and relative degree of excess dryness (in the negative W direction) as plotted relative to respectively mapped X and/or Y geographic coordinates of the wound site120. Wound center region R0is indicated to be too wet and the relative excess amount of liquid production (exudate discharge) is defined by the shape of waveform section151. Epitheliating wound zone R1is indicated in this example to be too dry and the degree of excess dryness (not enough clean moisture) is indicated by the shape of waveform section152as distributed over its respected X and Y coordinate points. Waveform section153may be read to indicate that moisture levels for the peri-wound zone127and adjacent healthy skin zone130of respective regions R2and R3are just about right prior to administration of a dressing (conventional or otherwise) onto the open wound site120and slightly beyond.

One of the dressing design parameters that can be associated with a respective wound site mapping and characterizing plot (e.g., plot150ofFIG. 1B) is the rate (R) at which liquid (moisture) should be removed from the underlying wound zone by one or more material layers of a corresponding, custom-designed wound dressing (see briefly, custom tailored dressing209ofFIG. 2). Such liquid removal profiles may be prescribed by a health care provider and/or automatically by a preprogrammed computer.FIG. 1Cshows an example of such a wound dressing function map in the form of a desired-liquid-removal rate plot160. The positive removal rate axis (+R) indicates a relative desired liquid removal rate for the respective X and Y coordinate points of the mapped wound site120. Waveform section161indicates that a relatively fast or high rate of liquid removal should be provided for the coordinates of exudating zone R0so as to counter-match the degrees of excessive wetness (+W) indicated by waveform section151of plot150. Similarly waveform section162indicates that an inverse moisture removal function (−R), in other words at least a blocking of excess drying if not injection or donation of additional moisture (and possibly medicines) should be provided in corresponding parts of region R1. The liquid removal/sourcing function plan160for the given wound site120indicates that the current rate of moisture removed by natural forces at wound zones R2and R3is about right and should not be changed as is indicated by waveform section163.

One of the ways in which moisture rates can be controlled is by appropriate selective patterning of an out-gassing layer (see briefly220ofFIG. 2) in a multi-layered custom dressing. Details regarding how permeation from different areas of an out-gassing layer can be selectively controlled are provided in the above-cited U.S. Ser. No. 11/972,451 (“Wound Dressing with Controllable Permeability”) whose disclosure is incorporated herein by reference. Briefly, microfiber pores may be closed or clogged in selected areas by thermal melting of polymer microfibers and/or by other means so that they no longer allow permeation of out-gassing vapors therefrom.

FIG. 1Dshows a third plot170indicating how out-gassing permeability (+P) of such an evaporation control layer (e.g.,220) can be selectively controlled to match the desired liquid removal rates versus geography as indicated by planning curve160(FIG. 1C). Wave section171indicates that water vapor should be allowed to out-gas rather rapidly so as to match the desired liquid removal rate of wave section161. As water vapor leaves from the out-gassing layer, additional room for further absorption is made available in a lower water absorbing layer (see briefly layer230ofFIG. 2). Thus liquid removal rate can be increased by increasing vapor permeation rates of the overlying permeation control layer. (Of course this depends on external humidity, air temperature, etc.) Waveform section172ofFIG. 1Dindicates that areas corresponding to region R1should be partially or fully blocked from allowing moisture to leave thus preventing excessive drying. Wave section173is provided inFIG. 1Dmerely for purpose of symmetry with corresponding sections ofFIGS. 1B and 1C.

With regard to waveform sections163and173(desired no changes), it will soon be explained in more detail how such non-change of conditions may be guaranteed for the healthy skin or peri-wound sections adjacent to an open wound site120. It will soon be explained in detail how such adjacent skin tissue can be protected from being damaged by exudates141(FIG. 1A) emerging from the wound and/or from being damaged by moisturizing liquids (e.g., medicines and/or pure normal saline water) applied to the wound as part of a treatment plan.

However, before delving into these details, attention is first focused toFIG. 2where a schematic diagram provides an overview of a custom-tailored product200that may be fabricated by automated means in accordance with the present disclosure. The custom fabricated product200includes a custom-tailored wound dressing209that is fabricated in accordance with the present disclosure to include, for example, custom tailored barriers262that are shaped and dimensioned to protect wound adjacent healthy skin when the dressing209is later applied to a corresponding wound (204c). The wound dressing209is further custom patterned to provide different functionalities for different zones of an individual open wound site such as120. The product200includes a protective packaging206/207/208which is provided to sealing-wise house the dressing209and maintain the dressing in a clean or sterile environment prior to application to a corresponding wound (e.g.,120). The protective packaging206/207/208also functions to route the contained dressing209to the correct patient and corresponding wound. In one embodiment, the clean/sterile packaging206/207/208has a first sheet or layer206which is also referred to here as the base packaging sheet even though layer206is shown to be topmost relative to the +Z reference frame. Packaging206/207/208also has a second sheet or layer208(optionally thinner than layer206) which is referred to here as the topside packaging sheet even though layer208is shown to be bottom-most relative to the illustrated +Z reference frame. Reasons for this will become clearer when the automated manufacturing process is described below (see brieflyFIG. 3A). Packaging sheets206and208are flexible, gas impermeable and sealed together at their peripheries by applying appropriate pressure to a flexible, gas impermeable and pressure sensitive adhesive (PSA) ring207that is preformed on topside sheet208. The PSA ring207is activated by the appropriate level of pressure to sealing bond the first and second packaging sheets206and208to one another at their peripheries.

The base packaging sheet206may include an integral base labeling layer205that is provided as an integral part of sheet206where label layer205may for example be a thermally printable white surface onto which a thermal printer (not shown) can automatically print identification and other information as desired at the time that sheets206/208are sealed together by PSA seal207and dispensed with custom dressing209enclosed between sheets206/208. The top side package sheet208may be composed of a transparent flexible plastic material which is gas impermeable as well as being impermeable to microbes or other contaminates. Packaging combination206/207/208is shown inFIG. 2with its base sheet206on top (highest in the +Z direction) and its top side sheet208below because that shows the orientation of the enclosed dressing209as the latter is applied to a corresponding wound (e.g.,120). In other words, when dressing209is removed from the package and applied, an uppermost, liquid-permeable mesh layer210of the dressing is positioned on top to serve as an interface with the outside environment (102) and a liquid-permeable wound contacting layer (could be250or240or230) is positioned below to interface with the wound and/or adjacent skin. During manufacture however, the base packaging sheet206is deposited first on a fabrication stage (see briefly306-305ofFIG. 3A) and then the liquid-permeable mesh layer210as well as an integrally attached out-gas control layer220(liquid-impermeable) are deposited on the base packaging layer206as shall be detailed below.

Product200may optionally include a computer-printed adhesive identification label204attached to the exterior of the topside package sheet208. In one embodiment, topside label204is automatically printed and thereafter attached to sheet208immediately after the package is sealed and dispensed for routing to a given wound on a given individual patient. The product200may thus have at least two patient identifying indicia formed thereon, one by means of topside label204and a second by means of base label205. Optionally, a third label (not shown) with mailing information thereon and a backside adhesive covered by a peel off wax paper may be attached to label204by a perforated paper coupling. When product200is being inserted into a mailing envelope (not shown), the user tears off the third label (not shown) along the perforations and sticks it to the outside of the mailing envelope. Optionally, further identifying indicia may be burned into an underneath side of layer220(or top of sheet315as the latter is shown inFIG. 3A). Although not shown inFIG. 2, layers210and220generally extend out in the X and Y lateral directions substantially further than layer230so that layers210and220can be adhesively or otherwise secured to healthy skin. The underside of this extended part of layers210/220may have patient identifying and wound identifying indicia burnt thereon with a polymer burning tool or otherwise formed thereon.

An example of patient/wound identifying and other functional indicia that may be provided is shown by way of example for the top side label204in the form of a magnifying glass symbol enlarged view204. As seen, label204may include a first identification204aof the specific patient for which the enclosed and custom tailored dressing209has been fabricated and is intended to be routed to. The label may further provide routing information204bindicating to whom next and how the sealed product200is to be routed. For example it may indicate that the product200is to be shipped directly to the patient's home or that it is to be routed indirectly to the patient by first hand delivering it to a pre-assigned caregiver (e.g., licensed nurse practitioner) who will then carry it to and apply it to the patient. The indicated method of routing may be by way of regular parcel post mail or by special delivery rush courier or by other means. The top side label204may further identify the specific wound (e.g.120) for which this specific dressing has been designed. Wound location identification may include one or more graphic images204csuch as schematic diagrams of a human body front and back with a spot marker indicating exactly where the wound dressing209is to be placed on the of the given patient204aand in what orientation. Wound location identification may further be provided by color coding of the topside label. For example, a patient or care giver may be taught that a green-colored label means this dressing goes on the back while a yellow label means the enclosed dressing goes on the left leg. Label204may further provide dates204don which the custom dressing209is to be applied to the wound and thereafter respectively removed. In some instances, a plurality of sealed products like200are custom formed at a same time under coordination of a care coordinating computer program (see briefly507bofFIG. 5B), then individuality sealed and sent in unison to the patient or nurse for sequential application over a doctor prescribed sequence of dates. In such a case, each dressing may have its own one of sequential and unique identification numbers (e.g., Rx numbers, not shown) included on label204. Information204dindicates the doctor-prescribed application and removal dates for its contained dressing.

The attached label204may further include more detailed instructions204efor application and/or removal of the correspondingly enclosed dressing209. For example, the prescribed application of the custom tailored dressing may call for provision of medicines or ointments to the wound or dressing prior to applying the dressing to the wound or the prescription may call for addition of such medicines, ointments, oils, etc. to the dressing209after it is applied to the wound. In one embodiment, an address of an internet web page (e.g., www.private123.com) is given on the label and when opened, the identified web page (e.g., a password secured page) provides detailed instructions for application and removal as well as a repeat of the patient identification information204aand wound identification information204cprovided by label204. Thus the whole of product200is seen to be a functional combination that is operative for routing a custom fabricated wound dressing209in sterile or clean form to the intended patient (101) and intended wound (120) for application thereto in a prescribed orientation at the doctor prescribed date and time204dand with optional addition of doctor prescribed addends (as specified by instructions204e). In one embodiment, the custom wound dressing209and enclosing packaging206/207/208as well as associated routing and/or use information (204a-c,204e) are automatically produced under control of a single coordinating computer program (e.g.,307bexecuting for example in a single coordinating computer—see307ofFIG. 3A) so as to assure that the correct dressing will be routed to the correct patient and applied to the correct wound at the right time with correct associated usage instructions. This helps to reduce the possibilities for foul up in each of the various steps that span from treatment formulation to treatment delivery. A user-friendly combination200is thus automatically manufactured and provided with associated informational indicia integrated thereon for routing the enclosed dressing209to the intended patient204aand to the intended wound204cand for application of the dressing on the wound as intended by the prescribing care provider (e.g., doctor).

Referring to the topmost dressing layer210inFIG. 2, and to the magnification201thereof, this topmost layer210may be fabricated as a nonwoven mesh of polymer microfibers where the microfibers are hydrophobic in nature, nonsoluble in water and provide a strong outer and scuff-resistant interface for interfacing with the external environment (102ofFIG. 1A). Average pore size between the intersecting microfibers of interface layer210is sufficiently large to easily let bulk water droplets through and as well as gases (e.g., water vapor) through. Any of a variety of relatively strong polymers may be used for forming microfibers layer210, preferably those with low friction and good scuff resistant properties. Methods for forming microfiber meshes are disclosed for example in the above-cited U.S. Pat. No. 7,105,058 whose disclosure is incorporated herein by reference. The present disclosure is not limited to the methods described in U.S. Pat. No. 7,105,058.

The second layer220of dressing209is also composed of a non-woven mesh of hydrophobic intersecting polymer microfibers. However the average pore size between the microfibers of layer220(see magnification202) is extremely small; generally less than about 0.5 micron and better yet, less than about 0.2 micron. As such, the pores are sufficiently small to block microbes and bulk water droplets from passing through. However these micro pores are sufficiently large to let one or more desired gases through such as water vapor. Thus, the second layer220forms a liquid impermeable and microbe impermeable barrier layer that can block infected exudates (e.g.,141ofFIG. 1A) from rising out of the wound120in the +Z direction and thereafter continuing to ooze out through the topside of the dressing209. The second layer220also prevents contaminated liquids or particles (e.g.,102bofFIG. 1A) from entering into the dressing in the −Z direction. Different regions of layer220, such as222may be custom patterned (e.g., selectively clogged) to further limit or to totally block out-gas permeation through those custom adjusted zones (222). Examples of how such custom control may be realized are disclosed in the above-cited U.S. Ser. No. 11/972,452 (“Wound Dressing with Controllable Permeability”) whose disclosure is incorporated herein by reference. The disclosed methods include selective heat melting of a bottom portion (as shown by area222inFIG. 2) of layer220with hot sterile air or with laser beams or other such selective heating means so as to melt the fibers in those selected zones and thus create a non-permeable film areas thereat. In one embodiment, second layer220is provided as an integrally fused part of a multilayer sheet material that also includes top layer210. The fused multilayer sheet material210/220is stretched over a fabrication stage (see briefly305ofFIG. 3A) and a custom shaped portion thereof is cut out with a cutting tool (301) and dropped onto the stage under directions of a fabrication coordinating computer307. In one embodiment, the first and/or second layers221/220have one or more through holes such as225formed therethrough (or perforations whereby cylindrical section225can be torn out) so as to allow coupling of liquids through the through holes225to or from an external liquid storage means. The through holes or tear-out perforated sections225may be pre-sealed with an impermeable polymer film that can be selectively removed with a corresponding solvent during automated dressing fabrication. This is done under direction of a fabrication coordinating computer307when the through hole or port section225is intended to be opened up for operative coupling to an external liquid storage means (e.g., a foam pad that is presoaked with sterile normal saline solution).

Still referring toFIG. 2, a third layer230of the custom dressing209is composed of hydrophilic and thermally meltable microfibers. Magnification203shows that the pores between the intersecting polymer microfibers of layer230are of medium size so as to let through both bulk liquid droplets and gases. The general use of this third layer230is to either absorb liquids into itself (into its pores) and/or to store and donate clean moisturizing liquids into to the wound depending on wound region and its treatment needs. The to-be-absorbed liquids may include exudates141emerging from the underlying wound As shall be detailed shortly, flow control barriers260such as those for controlling flow of aqueous solutions may be selectively formed as custom patterns that extend either entirely through the thickness of this third layer230or extend partially through the thickness of layer230as desired and in desired locations thereof. In one embodiment, barriers260subdivide third layer230into a central zone (corresponding to R0ofFIG. 1A) that is kept dry during fabrication and a peripheral (but not to the edge) zone that is filled with sterile saline solution during fabrication. Upon application of the custom dressing209to a corresponding pre-mapped and pre-characterized wound such as120(FIG. 1A), the pre-moisturized peripheral zone aligns with and donates moisture to a first wound zone that had been pre-characterized as a too dry wound periphery (e.g.,125). The non-moisturized dressing center aligns with and absorbs exudates from a second wound zone that had been pre-characterized as being an excessively wet. Thus each wound zone is specially treated according to its needs.

In some embodiments, the packaged custom dressing209is composed of just the first three illustrated layers210,220, and230. In other embodiments additional layers may be included such as the illustrated fourth layer240. Layer240is composed of hydrophilic microfibers with capillary soak up capabilities for drawing liquids up or down through layer240. Layer240has a corresponding bottom major surface241and layer230has a corresponding bottom major surface231. When a given liquid is transported into or out of the bottom of layer240, the bottom area for flow of that liquid through bottom surface241is not necessarily the same as the surface area used for moving that same liquid (e.g., exudates) through the bottom231of layer230. Funneling or other liquid flow controlling barriers such as260may be fashioned so as to define different surface areas for liquid inflow or outflow at respective bottom surfaces241and231of respective layers240and230. Additionally or alternatively, partial flow barriers such as262may block parts of lower surface241from passing liquids therethrough as will be detailed below. In either case, by adjusting the amount of surface area241available for transport of different liquids through the bottom of layer240and by adjusting the pass through surface areas at interface231, the designer of a custom dressing209may alter the rates at which different liquids move from one layer to the next and/or may alter the amounts of liquids absorbed or donated from one layer to the next. Thus the ability to create custom barriers like260and262in the composite wound dressing209gives the dressing designer an ability to better custom tailor the functions provided by the dressing209to match the treatment needs of a corresponding individual wound120.

The fifth, wound-interfacing layer250is also optional. It is shown for the purpose of demonstrating that different areas of the dressing that interface with the actual wound may have different local interface chemistries252depending on which chemicals are custom tailor wise donated into region252or removed from region252and also depending on the differing rates at which these various chemicals are transported out of or into the respective dressing regions.

The actual wound itself which alignably underlies interface surface251is of course not present inside packaging206/207/208but it is nonetheless shown in phantom inFIG. 2in order to show how a first pre-characterized wound zone291that is deemed to be too wet and thus requiring absorption of exudates therefrom aligns with a funnel enlarged absorbing volume in layer230and with a high gas permeation area of layer220. It also shows how a second pre-characterized wound zone292that is deemed to be too dry and thus requiring of the dressing to donate moisture to that area292is aligned with a barrier bounded, liquid donating volume of layer230(bounded by custom formed barrier262) and overlaid by a blocked gas permeation area222of permeation control layer220.

With the overview of product200now in place, attention is directed to a specific automated manufacturing process.FIG. 3Ais a perspective view showing a custom tailored dressing309at an intermediate state during its automated manufacture. The automated manufacturing process300includes the provision of a supporting stage305such a rigid flat metal plate. A base sheet306of a to-be-formed sealing package is stretched out over the stage, flattened thereon by for example moving a combination of supply and take up reels towards the supporting stage305or vise versa. Each step in the automated manufacturing process300may be controlled by a fabrication and packaging coordination program executing for example on a local coordination computer307. Computer307is understood to have appropriate hardware and software components including one or more data processors, memory and I/O interface circuitry (represented by307a) for interfacing with and controlling the various computer controlled mechanisms described herein including a motorized means (not shown) for dispensing base packaging sheet306on the support stage305.

In a next step of the automated process300, a multi-layered hydrophobic polymer microfibers sheet (not shown) is dispensed in stretched form above and vertically spaced apart from the base package sheet306. Such dispensing of the multi-layered hydrophobic polymer microfibers sheet is performed by a corresponding sheet dispenser (not shown) under control of computer307. A pre-specified shape315(e.g., rectangle with rounded corners) of prespecified dimensions is cut out from the dispensed and overlying hydrophobic multi-layered sheet (not shown) under control of computer307, and then deposited (e.g., dropped) on a prespecified region of the base package sheet306and flattened thereto. Multi-layer sheet section315corresponds to layers210and220ofFIG. 2. In one embodiment, a high temperature polymer cutting tool (vaporizing tool)301is used to cut out the shaped pattern315from a larger dispensed sheet. The polymer cutting tool301includes a ceramic cylinder that supports a twisted nichrome wire emerging from a bottom portion thereof. The nichrome wire (e.g. havingFIG. 8twisting) and its holding ceramic tube are operatively coupled to and translated by an X-Y position translator302that is controlled by coordinating computer307. The cutting tool301is further connected to and translated by a computer-driven Z translator303. Moreover, a computer-driven electric switch304selectively couples electrical power to the nichrome wire so as to turn its heating on and off, where the on state produces a polymer vaporizing temperature that vaporizes the material of sheet section315. In operation, the cutting tool301is first positioned by the X-Y translator302above a start point of a computer-defined cutting path. The heat is turned on (by actuating switch304) and then the Z translator303lowers the tool301to begin a polymer vaporizing traverse along a predefined X-Y cutting path. When the predefined cutting path is finished, the Z translator lifts the tool301up and the heating switch304is turned off. The shape and dimension of the hydrophobic multilayer sheet section315is thus defined to correspond to a pre-mapped and pre-characterized wound or wound zone. During the cutting, positive air pressure is maintained in the process chamber (not shown) that houses stage305and tool301so that the vaporized polymer material created by tool301escapes to a lower pressured ambient atmosphere.

In a next computer controlled step, out-gassing permeation rates through different areas of the cut out section315are optionally varied in accordance with the above-cited U.S. Ser. No. 11/972,451 whose disclosure is incorporated herein by reference. In one embodiment, a computer controlled hot air blower (see408ofFIG. 4A) is used to selectively melt polymer fibers in select subsections of cut out sheet section315.

Next, a second fibrous sheet composed of hydrophilic microfibers is stretched over the precut hydrophobic sheet315by action of a corresponding sheet dispenser and this second fibrous sheet is pattern cut under control of the coordinating computer307and with use of tool301. The cut out section330of the second dispensed fibrous sheet (not shown) is thereafter dropped onto to the stacked combination of base package sheet306and the cut out hydrophobic multilayered sheet315. Cut out section330is fastened to earlier cutout315by spot heat welding or otherwise. In one embodiment, the automatically shaped, dimensioned and deposited hydrophilic microfibers sheet330corresponds to layer230ofFIG. 2.

As part of the design for the custom tailored cutting of the hydrophilic microfibers sheet330, a certain overlay region (OL) is pre-specified where the custom-shaped sheet330will overlay on healthy or peri-wound skin. The shape and dimensions of the pre-specified overlay region (OL) may be stored in an operational memory of computer307.

FIG. 3Bis a side sectional view showing how the wound-matching hydrophilic microfiber layer330ofFIG. 3Ais intended to align with overlay peri-would zone327when the dressing309is later aligned over and applied to its corresponding wound380. Additional details inFIG. 3Bare that the hydrophobic multilayer sheet315may include a wide-pores layer310, an ultra narrow-pores layer320and a spot weld-forming lowest layer321. The melting temperature of fibers in lowest layer321is lower than the melting temperature of fibers at the bottom of layer320or the top of layer330. Thus, when a computer-controlled spot welding tool (not shown) having a temperature lower than the melt temperatures of layers330and320but higher than the melt temperature of layer321is compressively applied at a pre-selected weld point323, fibers in layer321melt and infiltrate into layer320above and layer330below to thus form a spot weld of molten material extending between and into layers320and330. When the welding tool is removed, the weld323solidifies and thus securely attaches sheet330to layer320. Prior to formation of the weld323however, different areas372of layer321other than where the spot weld323will be formed may optionally be premelted into layer320so as to clog gas permeating pores in layer320and thus custom adjust gas permeation rates through layer320. These selectively premelted areas are represented by ellipses372and372′.

A problem can emerge when a multilayer dressing such as that shown inFIG. 3Bis applied to a heavily exudating wound380. The liquids381which rise up out of the wound380and into the lowest layer330(e.g., hydrophilic layer) of the dressing may include undesirable components such as pus, bacteria, and toxic chemicals generated within the wound and removed therefrom as part of absorbed upflow381. Because layer330in its unpatterned form is isotropically hydrophilic, the absorbed exudates381can continue to diffuse laterally along phantom path382and thus migrate to the overlay area (OL) where dressing material330directly overlays on the peri-wound zone327and/or on adjacent healthy skin. These laterally migrating exudates382may damage or degrade the overlaid peri-wound zone327or adjacent healthy skin area (not shown) and thus undesirably cause an expansion of the wound as opposed to promoting healing.

Referring toFIG. 4Ashown is a perspective view of a next step400in the automated process300-400for fabricating the custom-patterned dressing under control of coordinating computer program307b. The further refined dressing is now denoted as409. In accordance with one aspect of the present disclosure, a liquid blocking barrier445is custom formed within the overlay region (OL) of the hydrophilic microfibers sheet430to block laterally diffusing and potentially harmful liquids such as exudates482(or moisturizing saline solution loaded into dressing region R1) from reaching and possibly degrading the overlaid skin or peri-wound areas (OL). This liquid blocking barrier material445is preferably formed from a material401awhich is itself non-toxic and not damaging to the overlaid skin zone327that is will lie over. Examples of flow blocking materials that may be used include water repelling materials (hydrophobic materials) such as silicones, silicone oils, mineral oils and vegetable oils. One or more of these skin-safe but water blocking materials may purchased or custom formulated (e.g., by appropriate distillation) to provide desirable viscosity, surface tension, capillary attraction and/or other properties as shall be explained shortly.

The chosen or custom formulated water repellant substance or substances is/are picked to have sufficiently moderate viscosities so that they can infiltrate relatively quickly into the microfiberous matrix of the liquid transport or liquid storage layer430in which it/they are to be embedded. The combined characteristics of layer430and the utilized water repellant substance(s)401aare such that after liquid401ainfiltrates in the +Z direction into a desired area of the target layer430(e.g., the wound-interfacing layer430) to a desired depth, liquid401abecomes resistant to further migration and it substantially maintains its post-infiltration shape and location under normal (e.g., room) temperature and/or other normal operating conditions. In other words, after having been deposited in the +Z direction onto the upward facing surface431of cutout sheet430of theFIG. 4Aduring the automated manufacturing process400, the infiltrating blocking material445holds itself together within the infiltrated porous layer430under normal dressing-use conditions due to one or more of viscosity effects, surface tension effects, capillary drawing effects and/or other effects so as to substantially maintain an outline of its deposited pattern and to thus function as a barrier against the flow of aqueous fluids (e.g., exudates) therethrough. In one embodiment, a silicone with a viscosity in the range of 1 centiStoke to 1000 cSt is used with a nominal value of around 5000 cSt. In another embodiment the viscosity of the utilized silicone is in the range of 100-1000 cSt with a nominal value of about 500 cSt. The specific viscosity used will vary from case to case depending on the porosity and/or other characteristics of the wound interfacing layer430. In one embodiment, medications or vitamins (e.g., vitamin E) are mixed in with the utilized silicone or other water repelling liquid401aso as to promote skin health at the region where the skin overlying outer barrier445is formed to contact with a corresponding skin area.

Intrinsic silicones tend to be colorless. However, non-toxic colored dyes may be added to them. See for example U.S. Pat. No. 4,737,537 (Colored Silicone Composition) whose disclosure is incorporated herein by reference. See also WO/2005/102675 (Curable Colored Inks for Making Colored Silicone Hydrogel Lenses—U.S. provisional 60/564,024) whose teachings are further incorporated herein by reference. In accordance with one aspect of the present disclosure, silicones or other water repellant barrier liquids may be optionally colored by adding non-toxic dyes thereto so as to form readily visible boundary lines or curves (e.g.,445and443ofFIG. 4A) on the wound facing surface431of a custom wound dressing. Users may then be instructed to infuse water, saline solution or specific medications into visibly bounded regions (e.g., R0, R1ofFIG. 4A) on a custom tailored dressing. Colored silicones need not be used exclusively for forming barriers. It is within the contemplation of the present disclosure to mark the face of a wound contacting dressing layer with pre-colored silicones or the like, whether while simultaneously creating a barrier line with the colored liquid material or not.

Deposition of the fluid flow barrier material401aand its infiltration into the wound-interfacing layer430to form the embedded barrier445may take on many forms. As already mentioned, in one embodiment, the viscosity of the water repelling material401ais chosen so that it can infiltrate into the pores of the microfibrous material430fairly rapidly at room temperature and yet will remain in its infiltrated original shape within the microfibrous polymer material430after infiltrating due to surface tension effects, capillary effects and so forth.

In a second embodiment, a viscosity-lowering solvent is mixed together with an otherwise high viscosity, water repelling material. The mixture401aof solvent(s) and water repelling material(s) is then selectively deposited as drops over the overlay region (OL), for example by using a repellent dripping tool401whose position and drip rate are controlled by coordinating computer307′. As seen inFIG. 4A, dripping tool401of one embodiment is operatively coupled to and translated by the same computer-driven X-Y translator402/302as used for controllably translating cutting tool301ofFIG. 3A. The repellent dripping tool401is also operatively coupled to a computer-controlled drip rate controller403. Droplets401aare released at an appropriate rate corresponding to movement by the X-Y translator402after the translator has brought the dripping tool (capillary) over a desired start point where the to-be-embedded barrier445is to be formed. After the water repellent material401awith its included viscosity-lowering solvent infiltrate into the wound-interfacing layer430at normal room temperature, the material is heated to an above-normal temperature but not one at or above the melt temperature of the dressing polymers. The raised temperature volatilizes and removes the viscosity-lowering solvent and/or at the same time temporarily reduces the viscosity of the left behind barrier material so that the latter may diffuse vertically and/or laterally by a predetermined amount. Localized heating may be provided for example with an X-Y driven hot air guiding tube408such as shown inFIG. 4A. After the solvent is driven off and temperature of the left behind water-repelling material445returns to room temperature, the viscosity of this left behind water-repelling material445is substantially reduced and its self coherence is increased due to removal of the solvent and removal of localized heating. As a consequence, material445retains its post-deposition and post-infiltration shape and thickness as well as its relative position within the dressing material. By overlapping deposited drops401a, a continuous barrier445may be formed that fully covers the to-be-protected surrounding skin of a given wound. Of course, the protective barrier may alternatively be patterned to be other than fully continuous and fully covering (e.g., it may be patterned as a plurality of spaced apart dots). The specific pattern created under control of fabrication coordinating computer307may vary and depend on the specific treatment plans devised for the corresponding wound dressing409by a prescribing health care provider.

In yet another embodiment, water repellent material401aof relatively high viscosity is dripped on top of surface431at desired positions where the high viscosity is such relative to the pores sizes of layer430that the dripped on material401adoes not readily infiltrate into the microfiberous matrix of layer430but instead remains puddled on its top surface431at the point of deposition (e.g., in the OL region). Then the viscosity of deposited material is temporarily lowered by heating with a heating tool such as408(e.g., to a temperature above 25° C. but below the melt temperature of layer430). The heated barrier material401athen temporarily decreases in viscosity due to the raised temperature and infiltrates into the microfiber matrix of layer430to become imbedded therein. When the heat is removed, the viscosity of the infiltrated material445increases again and it thus becomes relatively fixed in its embedded position within layer430. In one embodiment, heating tool408receives filtered air through a flexible plastic tube450. The air heating tube and an included resister (heating element) thereof are translated by X-Y translator402/403. Electric heating of the resistive element in tube408is controlled by a computer-driven on/off switch404. Filter461protrudes through a relatively air-tight chamber casing460where the later houses the in-fabrication dressing409. The air filter461has pore sizes sufficiently small to block out microbes from entering into the sterile interior environment of the casing460. Blower470maintains positive air pressure within the casing interior so that unclean air cannot enter. Prior to use, the barrier forming material401ais kept in essentially sterile condition so that its introduction into layer430will not inadvertently contaminate the dressing with harmful microbes. In one embodiment, prior to use in fabricating dressings, one or more of the barrier forming material401a, the drip tool401and the heating tool408(as well as flexible tube450and filter461) are subject to gamma irradiation of sufficient intensity to render them medically sterile.

In addition to forming the outer protective barrier445for blocking harmful fluids from reaching the skin overlay region OL, additional custom shaped and dimensioned water repellent barriers such as443may be formed through the thickness of the wound-interfacing layer430′ as shown inFIG. 4B. In the illustrated example, dressing region R1corresponds to epitheliating wound zone128ofFIG. 1A. Since in the given example it is desirable to keep the epitheliating wound zone128somewhat moisturized while preventing the exudating discharge381from the center of the wound140from reaching epitheliating wound zone128; the inner barrier443is custom patterned to fully surround exudating wound zone R0. Additionally, after the inner barrier443is embedded into layer430′, a moisture providing liquid such as clean water or saline solution or a medicine containing solution is deposited into the barrier embraced, intermediate region R1of layer430′. Outer barrier445keeps this deposited moisturizer from reaching the overlaid skin of overlay zone OL. Inner barrier443keeps the deposited moisturizer from being contaminated by exudates that enters central region R0of layer430′. The gas impermeable patterned region472overlying and engaging with barriers443and445keeps the deposited moisturizer of dressing region R0from evaporating away into the ambient. Accordingly, the prescribed moisturizer in dressing region R0is directed to only the pre-mapped wound zone where it is intended to be applied and it is blocked from dissipating wastefully or harmfully into other areas. It is to be noted here that even in the case where the prescribed moisturizer in dressing region R0is simply clean water, the latter can damage or degrade adjacent skin if the skin is exposed to the water for too long of a time. However, the silicone or other nontoxic material used for forming the outer barrier445protects the overlaid skin and blocks it from being damaged from harmful liquids including moisturizing water and/or exudating discharge482. It is also to be noted that during fabrication, the inner barrier-surrounded dressing region R0is kept dry due to presence of inner barrier443while one or more moisturizing liquids are selectively deposited into adjacent dressing region R1. The kept-dry, inner dressing region R0may then absorb a maximum amount of exudates when it is later applied to the corresponding wound480. Water vapor483may readily evaporate out from the absorbed exudates482and escape into the ambient through permeation control layer320so as to make room for absorption of additional exudates into dressing region R0. In one embodiment, after the moisturizing clean liquid(s) is/are deposited into dressing region R1with a computer-controlled selective dripper similar to tool401, surface431of the patterned dressing layer431is covered with a peel-off wax paper or impermeable plastic sheet that traps the clean liquid(s) in dressing region R1until the custom dressing409is about to be applied to its corresponding wound480. If such a peel-off sheet is included in the packaged product (seeFIG. 2), the corresponding dressing usage instructions will typically include an instruction to remove the peel-off sheet prior to application to the corresponding wound480.

FIG. 5Ais a side sectional view showing how more complex fluid routing and/or blocking barriers may be formed within multiple layers (e.g.,530,540) of hydrophilic absorbent sheets in a wound dressing product500so as to direct flows of different fluids to or from pre-identified and pre-characterized wound zones. Here, a second hydrophilic fibrous layer540is cut, deposited, fastened on (e.g., spot welded on) and patterned after a previous hydrophilic layer530has been cut, deposited, fastened on (e.g., spot welded on) and patterned in accordance with computerized first hydrophilic layer defining data (see briefly507eofFIG. 5B). The bulk material of the second hydrophilic fibrous layer540may be the same as or different from the bulk material of the first hydrophilic fibrous layer530. In the automated patterning of the first layer530, an upper and close bounded water repellent barrier535is deposited and somewhat fixedly embedded into the thickness of porous layer530as shown. Region R00is designated by a corresponding computer-readable data structure (507e) as having the function of absorbing exudate582that enters into layer530while region Rx is designated by the corresponding computer-readable data structure (507e) for donating late stage moisture and/or a prescribed medicine. After the water repellent material of upper barrier535has been embedded into layer530, a patterned fluid impermeable film531b,531dis formed on the −Z facing major surface of layer530and optionally (as in the case of531d) around its peripheral edge by for example depositing a hardenable polymer film material or by melting selected parts of the −Z facing major surface (531) of layer530at desired positions. This selective patterning of the −Z facing major surface of layer530leaves liquid and/or gas permeable passageways531aand531con that surface and between the first and second layers530,540while locking the upper water repellent barrier535in place. Optionally, open liquid passageway531cis then used for infusing clean water or saline solution and/or a liquid medicine into region Rx of the first hydrophilic layer530before next layer540is attached. Although in one embodiment, the laterally extending barriers531b,531dto liquid and/or gas flow are formed by deposition of an impermeable film laterally on the −Z face of layer530, such laterally extending barriers could additionally or alternatively be custom shaped, dimensioned and formed by selective deposition and embedding of a water repellant viscous liquid that only partially penetrates into the thickness of layer530similar to the way that selectively deposited liquid region543b(described below) only partially embeds into the thickness of next-described layer540.

After patterning of layer530is substantially complete, the second hydrophilic layer540is then shaped and dimension (e.g., by custom cutting with tool301for example) and attached (e.g. spot welded to layer530—welds not shown). Thereafter lower water repellent barriers545and543aare selectively embedded fully through the thickness of layer540as shown. Optionally, a less viscous and thus more readily spreadable silicone or other water repellent liquid543bis deposited into region R1′ of layer540just before water or another moisturizer is selectively infused into region R1′. The viscosity of this more readily spreadable but water repellent liquid543bis such that were it not for the water (or other moisturizer) consuming the remaining volume of region R1′, the readily spreadable repellent liquid543bwould over short time (e.g., 15-30 minutes) begin to spread out over region R1′ rather than retaining its shape as well as do barriers535and543a. However, the water (or other moisturizer) that is quickly infused into region R1′ after readily spreadable repellent liquid543bhas been infused, pushes the readily spreadable repellent liquid543bup against less spreadable barrier543aand prevents543bfrom spreading out laterally as long as there is sufficient aqueous liquid present in dressing region R1′ to push against readily spreadable repellent liquid543b. On the other hand, during end stage use of custom dressing509on corresponding wound580, the aqueous liquid in dressing region R1′ substantially runs out and then spreadable repellent liquid543bspreads out across the wound interfacing surface531of dressing region R1′ to thereby close off region R1′ and block moisture from being absorbed from the wound into the substantially dried out region R1′. In this way, the custom dressing509dynamically adapts itself to changed conditions and keeps an epitheliating wound zone (not shown) under region R1′ from drying out.

While frusto elliptical section543bhas been described for one embodiment as being composed of a readily spreadable embedded hydrophobic liquid, in an alternate embodiment it constitutes a more fixedly embedded hydrophobic liquid that provides one or more functions including that of reducing the water-permeable surface area by way of which region R1′ interfaces with the underlying wound580or defining a water-permeable passageway of desired thickness between the top of frusto elliptical section543band a spaced apart horizontal barrier such as the illustrated531b. In both instances, the rounded top of frusto elliptical section543bdoes not need to abut with water-impermeable horizontal barrier531bor with the bottom of a water-impermeable layer such as520. In other words, when it is formed, the frusto elliptical section543bdoes not have to infiltrate all the way through the thickness of its supporting dressing layer540. Depth of penetration by the precursor material (e.g.,401a) of frusto elliptical section543binto layer540can be varied by adjustment of the heating temperature used to cause the precursor material (e.g.,401a) to infiltrate vertically into layer540or by the adjustment of heating time (for material401aor for a volatile solvent mixed with it) or by the volume of precursor material (e.g.,401a) deposited as a drop on surface541. When frusto elliptical section543bserves as a baffle for reducing water-permeable space between its +Z top and an overhanging horizontal barrier (e.g.,531b), it may be used to controllably limit the flow rate of an aqueous liquid from one compartment in the dressing to another by controlling the distance between its +Z top and the overhanging horizontal barrier (e.g.,531b).

It is to be understood from the above that the present disclosure is not limited to just depositing water repellent liquids to form static barriers. Viscosity may be adjusted, for example by selectively depositing different silicones of different viscosities and optionally mixed with nonvolatile solvents so as to provide relatively static barriers in some locations of a given dressing layer and so as to provide relatively dynamic, more easily spreadable barriers in selected other locations of a given dressing layer. While only frusto elliptical section543bhas been described in one version thereof as being readily diffusible through region R1′ of layer540, a same tactic could have been used in other dressing regions Rx and R1ofFIG. 5Aby infusing readily spreadable repellent liquids like543bin respective regions Rx and R1just before those regions are respectively filled with respective aqueous liquids (e.g., a medicine in region Rx and saline solution in region R1). Then as the respective aqueous liquids run out from their storage compartments in the dressing, the dynamically spreadable barriers (not shown) of regions Rx and R1would spread out to close off those regions during late stage usage of the dressing509and would prevent undesired drying of the underlying wound zone. Note that melt zone572in layers520-521caps the Rx region of layer530and thus keeps the Rx region of layer530from drying out due to undesirable outgassing through layer520.

Additionally, since upper region R00of layer530has been kept dry by operation of upper barrier535and since upper region R00is not capped by an out-gas blocking film above it, the upper region R00of layer530is available to absorb large amounts of exudates from region R0′ of lower liquid540and to readily dissipate water vapor583via the enlarged upper surface area of upper region R00. In other words, the surface area of the upper part (in the +Z direction) of dressing region R00is not constrained by dimensions of underlying wound zones as much as the wound interfacing layer540may be. With use of vertical barriers like543aand horizontal barriers like531b, funneling structures may be devised for expanding the water vapor dissipating surface area made available for a given one or more wound zones. Accordingly, when custom dressing509is applied to wound580, exudate flow581is absorbed not only into region R0′ of lower layer540but rather it continues to migrate upwardly, passing through the intentionally left open liquid passageway531aand then spreading out laterally into wider region R00of upper layer530. Note that the wider lateral area of region R00means that it has greater volume (assuming layer540is not thicker than layer530) and thus can absorb aqueous liquids at a faster rate and evaporate off water vapor583at a faster rate form its larger upper surface area. The availability of patternable vertical barriers like535,545,543a, etc. and patternable horizontal barriers like531band572give designers of automatically fabricated custom wound dressings an enlarged number of options by way of which they can control directions, rates and timings of liquid flows going into a given wound (e.g., medicine Rx) and liquid flows moving out of the given wound (e.g., exudates581). Additionally, by providing more readily spreadable barriers such as543bwithin one or more dressing layers, designers can define dynamically closeable passageways which close up after a corresponding liquid content has run dry. Thus a wound dressing can be designed to dynamically adapt to changing conditions.

Referring to schematic diagram5B, it is to be appreciated that a single coordinating computer program507bcan be executed either in a corresponding single coordinating computer507or across a plurality of networked processors (not shown) so as to assure that a matching custom dressing (e.g.,509ofFIG. 5A) is correctly fabricated for a given individual and pre-mapped wound (e.g.,580,580′) and that the same matching custom dressing is automatically packaged in a sealed package, that the dressing containing package is automatically labeled so as to be appropriately routed (593) after fabrication (592) to the same individual wound (e.g.,580′) for application to the wound at a physician prescribed time point. In other words, a full circle of control and coordination may be provided from the time of wound mapping and characterization (591) to the time of dressing application (593) and the time of dressing removal (594). To do so, the coordinating computer program507bmay logically interlink a plurality of data files or other data structures including but not limited to: a digitized wound map or image507cof the specific wound (which map corresponds to a predefined physical reference frame such as one formed by specific X and Y coordinates on the patient's body); digitized wound characterizing maps and/or plots507d(see alsoFIGS. 1B-1D); digitized, layer by layer, dressing design maps507e;digitized patient identifying and wound identifying data507f;digitized routing data507gfor defining how the fabricated dressing is to be routed to the patient (e.g., via an identified doctor and/or nurse) after fabrication and packaging is complete; and digitized application and/or removal information507hfor defining when and/or how the corresponding custom dressing (509) is to be applied to its corresponding wound and when and/or how the corresponding custom dressing (509) is to be removed from corresponding wound.

It is to be understood that the digitized patient identifying and wound identifying data507fmay be used multiple times including for associating the digitized wound image507cwith the actual wound, for associating the automatically fabricated dressing509with the actual wound; and for printing out or otherwise generating routing data507gthat causes the packaged product to be correctly ultimately routed to the same actual wound580′. In one embodiment, the digitized patient identifying and wound identifying data507fand the digitized routing data507gare formed as computer data files at substantially the same time and in substantially the same location as the digitized wound map or image507cis created (and generally by a same person for all three files) so that the wound map or image507cis correctly attached or otherwise logically associated with and tied to the patient identifying and wound identifying data507fand to the routing data507gfrom the point of inception of the wound image. This minimizes the risk that a wrong dressing will be applied to a wrong wound or even a wrong patient or not properly or timely delivered to the patient due to accidental mix up of one or more of these pieces of functional information.

The digitized wound characterizing maps and/or plots507dand corresponding treatment plans (which could be digitized text notes appended to the wound zone characterizing maps) are typically generated by a doctor or other skilled health care providing professional(s) at the same time (and/or same place) that the digitized application and/or removal information507his generated so that the two files (507d,507h) correctly correlate with one another. The latter two files (507d,507h) are then appended to or otherwise logically connected to at least the digitized patient identifying and wound identifying data507fand the digitized routing data507g. In one embodiment, the digitized wound characterizing maps and/or plots507ddelineate skin zones and/or other zones that are to be protected from exposure to exudates or other tissue harming substances by use of one or more fluid containment barriers such as for example those made with embedded viscous silicones or the like. In one embodiment, the digitized wound identifying data507fincludes data identifying and locating on the identified patient, a frame of reference (e.g., corresponding to X/Y frames shown inFIG. 5B) relative to which the wound dressing is to be oriented and identifying the prescribed orientation of the dressing. The digitized routing data507gmay include an audit trail that identifies the doctor(s) or other skilled health care providing professional(s) who characterized the wound zones and the adjacent skin areas that may need protection, and who created the treatment plan. The routing data507gmay also identify the doctor(s), nurse(s) or other skilled health care professional(s) who are delegated the task of aligned-wise applying the wound dressing to the identified wound and/or removing the wound dressing from the identified wound at the treatment prescribed appropriate times. This minimizes the risk that a wrong dressing will be designed, fabricated and applied to a wrong wound or even a wrong patient or not properly or timely delivered to the patient or not properly removed from the wound due to accidental mix up of one or more of these pieces of functional information regarding routing and responsibility for data management and for use of the associated custom wound dressing or the packaged product that includes the custom wound dressing. Since in one embodiment the responsible people are so-identified by a file kept in a database and logically associated with the identified patient and identified wound, a game of finger pointing cannot be later played so as to escape responsibility regarding who had the responsibility to make sure the right custom dressing is correctly applied to the correspondingly matching wound at the appropriate time and thereafter removed at an appropriate time.

The digitized dressing design maps507ecan be generated in automated response to the digitized wound characterizing maps and/or plots507dand corresponding treatment plans or they may be generated by a skilled dressing designer with automated assistance provided by a computer (e.g.,507) that suggests to the dressing designer what shapes, sizes and materials should be picked for each dressing layer, how many dressing layers should be used for each treatment function and how vertical and/or horizontal fluid containment barriers (e.g.,543a,543b,545,531b,572) should be shaped, dimensioned, located and formed of respective fluid containing materials in or between the various dressing layers. It is therefore understood that the digitized dressing design maps507ecan include specifications for the shapes, dimensions, locations and/or fluid containing materials to be used for forming respective vertical and/or horizontal fluid containment barriers (e.g.,543a,543b,545,531b,572) within or on the surfaces of the various dressing layers. In one embodiment, the digitized dressing design maps507einclude specifications for the shape, dimensions, locations and/or barrier forming materials to be used for protecting adjacent skin from harmful substances such as is done for example by lower barrier545ofFIG. 5A. The digitized dressing design maps507emay further include information regarding amounts, locations, and identities of one or more prespecified liquids (e.g., water, saline solution, peroxide, antiseptics, etc.) that are to be applied to prespecified liquid containment areas of the customized wound dressing after removal from the package206/207/208but prior to application of the dressing to a corresponding wound.

It is also to be understood that the digitized dressing design maps507emay be appended to otherwise logically associated (e.g., in a relational database) with one or more of the other data files507c-507d,507f-507hand that the digitized dressing design maps507emay be used for controlling automated fabrication (592) of the corresponding wound dressing509. Identification of the person or persons respectively responsible for generating the digitized dressing design maps507eand for responsively fabricating the corresponding wound dressing509may be appended into the digitized routing data file507gat the times of respective dressing design and dressing fabrication. The unique identification number (e.g., Rx number, not shown) that is optionally included on label204may be submitted, in one embodiment, to a relational database (e.g., one implemented in computer507) after the wound dressing is fabricated and all of files507c-507hcontained therein may be responsively retrieved for review and evaluation. The relational database may include additional files or records that logically tie to the unique dressing identification number (e.g., Rx number, not shown) and that indicate how well the patient responded to the automatically designed and automatically fabricated custom wound dressing509and/or to medicines or other substances added thereinto.

The present disclosure is to be taken as illustrative rather than as limiting the scope, nature, or spirit of the subject matter claimed below. Numerous modifications and variations will become apparent to those skilled in the art after studying the disclosure, including use of equivalent functional and/or structural substitutes for elements described herein, use of equivalent functional couplings for couplings described herein, and/or use of equivalent functional steps for steps described herein. Such insubstantial variations are to be considered within the scope of what is contemplated here. Moreover, if plural examples are given for specific means, or steps, and extrapolation between and/or beyond such given examples is obvious in view of the present disclosure, then the disclosure is to be deemed as effectively disclosing and thus covering at least such extrapolations.

By way of example, it is understood that the configuring of a coordinating computer (e.g.,507ofFIG. 5B) in accordance with the disclosure can include formulation of algorithms that take advantage of the ability to form custom patterned vertical and/or horizontal barriers for one or more layers of a multi-layer custom dressing. As such, machine executable instructing signals may be stored in a functional storage of a computer to determine one or more barrier defining parameters including but not limited to: which of plural barrier forming liquids to use, where to deposit the selected barrier forming liquids and to what depth; what order to deposit the selected barrier forming liquids in; what temperature to heat the deposited barrier forming liquids to if at all; what overlying or underlying horizontal barriers to form adjacent to the vertical barriers; and so forth. A computer-readable medium (e.g.,507b) or another form of a data storage product (including but not limited to, a hard disk, a compact disk, a flash memory unit, a downloading of manufactured instructing signals over a network and/or the like may be manufactured and used for defining one or more data structures for custom fabricating a wound dressing for a corresponding individual wound where the data structures include one or more of a wound zones map, a wound zones characterizing map, layer by layer dressing design maps, patient and wound identification data, dressing routing data and dressing usage data; where the data structures are logically linked to one another to thereby verify that not only a correct custom dressing is automatically fabricated for a given wound, but that the fabricated dressing is thereafter timely routed to the corresponding wound.

Reservation of Extra-Patent Rights, Resolution of Conflicts, and Interpretation of Terms

After this disclosure is lawfully published, the owner of the present patent application has no objection to the reproduction by others of textual and graphic materials contained herein provided such reproduction is for the limited purpose of understanding the present disclosure of invention and of thereby promoting the useful arts and sciences. The owner does not however disclaim any other rights that may be lawfully associated with the disclosed materials, including but not limited to, copyrights in any computer program listings or art works or other works provided herein, and to trademark or trade dress rights that may be associated with coined terms or art works provided herein and to other otherwise-protectable subject matter included herein or otherwise derivable herefrom.

Unless expressly stated otherwise herein, ordinary terms have their corresponding ordinary meanings within the respective contexts of their presentations, and ordinary terms of art have their corresponding regular meanings within the relevant technical arts and within the respective contexts of their presentations herein. Descriptions above regarding related technologies are not admissions that the technologies or possible relations between them were appreciated by artisans of ordinary skill in the areas of endeavor to which the present disclosure most closely pertains.

Given the above disclosure of general concepts and specific embodiments, the scope of protection sought is to be defined by the claims appended hereto. The issued claims are not to be taken as limiting Applicant's right to claim disclosed, but not yet literally claimed subject matter by way of one or more further applications including those filed pursuant to 35 U.S.C. §120 and/or 35 U.S.C. §251.