Patent Description:
A variety of devices can be applied to a patient to provide a treatment or monitor a patient condition. Some can do both. One example is an infusion system used to deliver substances such as fluids and medications into the subcutaneous layer of skin of a patient. Typically, a subcutaneous infusion system includes a site applied to the surface of the skin of a patient, the site having a cannula that is introduced into the skin, as well as a tube extending from the site to, for example, an infusion pump to deliver the substance. Another example is a patient monitoring system used to check or monitor one or more conditions of a patient (e.g., blood levels, such as glucose or oxygen), which also can include a device applied to the skin of the patient and comprising a cannula, filament, wire or other device introduced at least partially subcutaneously. For convenience, surface devices generally, whether for infusion, monitoring or some other purpose, will generally be referred to herein as sites. In some embodiments, sites refer to sensors or "patch pumps".

In current designs, it is typically necessary to introduce the cannula or other device of the site into the skin of the patient while maintaining the site at a given orientation. The orientation of the cannula is also fixed, extending perpendicularly from a bottom surface of the site and therefore inserted straight into, or perpendicularly to, the surface of the skin. While this perpendicular orientation can require a shorter cannula and a shorter needle for insertion of the cannula while also being easy and convenient for user self-application using an insertion aid device, perpendicular insertion can be inconvenient for some users, such as those with low body fat or who are active and desire a more secure placement of the infusion device and cannula. Additionally, some users may wish to control the angle of insertion of the cannula, depending on location and anatomy, to increase comfort and placement efficacy. Still others may find the perpendicular orientation difficult to administer when applying the site to some locations on the body.

In addition, devices for assisting in insertion of the cannula of an infusion device into the skin of the patient are known. For example, some devices utilize springs to automatically drive a needle into the skin of a patient to introduce the cannula of the site into the subcutaneous layer. Because a needle is used to introduce the cannula of the infusion device into the subcutaneous layer of skin, there is a risk associated with inadvertent exposure to the needle. Further, patients may react adversely to viewing the needle prior to insertion and may, for example, be reluctant to self-insert the needle into the skin. Prior devices may not adequately shroud the needle prior to and/or after introduction of the site.

Other issues of concern in the design and use of insertion devices include ease of use by the patient and sterility. For example, some patients may have difficulty loading an infusion device into an insertion device.

It is therefore desirable to provide new designs for subcutaneous inserter devices and other devices used to assist in the introduction of a device into the skin of a patient.

<CIT> discloses an infusion device for delivery of a substance to a patient.

<CIT> discloses systems and methods for transcutaneous measurement of glucose in a host.

The invention provides an insertion device according to claim <NUM>.

Subject matter hereof may be more completely understood in consideration of the following detailed description of various embodiments of the subject matter in connection with the accompanying drawings, in which:.

While embodiments are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit subject matter hereof to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of subject matter hereof in accordance with the appended claims.

Embodiments relate to subcutaneous insertion systems comprising a site or other surface device to be applied to a patient and an insertion system for applying the site or other surface device to the patient, wherein the applying can include subcutaneous insertion of a cannula or other element, and related devices and methods. The site or other surface device can comprise a device applied to the skin of the patient and comprising a cannula, filament, wire, sensor or other subcutaneous element to be introduced at least partially subcutaneously into the skin of a patient. For convenience, sites and other surface devices generally, whether for infusion, monitoring or some other purpose, will generally be referred to herein as sites. In some embodiments, sites may refer to sensors or "patch pumps".

In an embodiment, a subcutaneous insertion system comprises a site and an insertion device for applying the site to the skin of a user. The site comprises a surface for application to the skin of a patient and a subcutaneous element, such as a cannula, filament, wire, sensor or other subcutaneous element to be introduced at least partially subcutaneously into the skin of a patient, extending from the surface at an angle greater than <NUM> degrees and less than <NUM> degrees. The site can be preloaded in the insertion device, which comprises a needle configured to interact with the cannula or other subcutaneous element to insert the cannula or other subcutaneous element into the skin of the patient at an angle greater than <NUM> degrees and less than <NUM> degrees with respect to the surface of the skin of the patient as the site is applied to the surface of the skin of the patient by the insertion device. The insertion device is configured to retract and securely retain the needle in an inaccessible portion of the insertion device after insertion of the cannula or other subcutaneous element. In embodiments, the subcutaneous insertion system can further comprise a set comprising tubing and configured to be removably coupled to the site while on the skin of the patient in order to convey fluid from a source coupled to the set to the patient via the tubing, site and cannula. In still other embodiments, devices and elements other than tubing sets can be mechanically, electrically and/or communicatively coupled with the site following application to the skin of the patient. The site (or "payload") can be circular, elliptical, rectangular, or modifications of those general shapes.

While the type of surface device and subcutaneous element can vary in embodiments, examples discussed herein generally relate to an infusion site comprising a cannula. These examples are used without limitation or effect on the scope of the claims, as various other types of devices and elements are contemplated and may or may not fall within the scope of the claims. Some of these other devices and elements include patient monitoring systems and devices used to check or monitor one or more conditions of a patient (e.g., blood levels such as glucose, carbon dioxide, or oxygen) or body temperature, which also can include a device applied to the skin and comprising a cannula, filament, wire, sensor or other device introduced at least partially subcutaneously. Still other devices can be used in embodiments for application in or on the skin of a patient, including those with a different type of or without a subcutaneous element, with a plurality of subcutaneous elements, or with a subcutaneous element as well as surface elements (e.g., sensors or other devices configured to monitor a patient condition at the surface of the skin, independent of or in combination with a subcutaneous element). In some embodiments, a site may comprise a "patch pump" or similar device which may include its own fluid reservoir, power mechanism, power supply, electronic circuitry and cannula insertion system.

Referring to <FIG>, an exploded view of an embodiment of an insertion device <NUM> is depicted. As depicted, insertion device <NUM> comprises a housing <NUM>, a needle hub assembly <NUM>, a cylinder hub <NUM>, a biasing element <NUM>, a sleeve <NUM>, a cap <NUM> and a lock pin <NUM>.

Lock pin <NUM> secures cap <NUM> to housing <NUM> via an aperture <NUM> in housing <NUM> and an aperture <NUM> in cap <NUM> and can also abut or otherwise interact with sleeve <NUM> to prevent sleeve <NUM> from moving within housing <NUM> and cap <NUM>. This can prevent inadvertent activation of insertion device <NUM>, such as if insertion device was inadvertently dropped or jarred, while also providing a child safety feature. Lock pin <NUM> can form part of or be coupled with a tear-away band <NUM> that can be part of cap <NUM> or housing <NUM>, such that removing tear-away band <NUM> removes lock pin <NUM> and enables cap <NUM> to be decoupled from housing <NUM> while also freeing sleeve <NUM> for movement. Cap <NUM> can comprise a label <NUM> in embodiments, wherein the label identifies at least one of a manufacturer of insertion device <NUM>, name of insertion device <NUM>, a serial number of insertion device <NUM>, a barcode or other computer-readable identifier, instructions or warnings with respect to use of insertion device <NUM>, and the like. Cap <NUM> can include a raised annular rib around its inner surface near the proximal end. This rib can be continuous or discontinuous. In some embodiments, the choice of cap design could be influenced by the sterilization method used on the device.

Insertion device <NUM> can be preloaded with or otherwise comprise a site <NUM> including a central hub <NUM> extending upwardly from a top surface or side of site <NUM>. In still other embodiments, site <NUM> is not pre-loaded within insertion device <NUM> and instead can be coupled with insertion device <NUM> just prior to application of site <NUM> to the skin of the patient. Site <NUM> can be coupled with a site pad <NUM> and sleeve pad <NUM> on a bottom surface or side opposing its top surface. In other embodiments in which site <NUM> is differently configured and/or comprises a different type of device, the configuration of site pad <NUM> and/or sleeve pad <NUM> can vary, or one or both could be omitted or replaced by a different element. Here and elsewhere in this document unless otherwise specified, a "top" surface generally refers to an upper surface as the drawing is oriented on the page, while a "bottom" surface generally refers to the opposite, lower surface in the drawing, without limitation with respect to how the device or element may be oriented in use and operation or other situations. This convention is used for other elements and features herein throughout as well, unless otherwise specified.

Site pad <NUM> can couple or interface between site <NUM> and sleeve pad <NUM>, while sleeve pad <NUM> can be configured to removably secure site <NUM> to sleeve <NUM> before application of site <NUM> to the skin of a patient. Sleeve pad <NUM> can comprise an adhesive layer, such as one comprising TEGADERM or another similar adhesive suitable for application to human skin or tissue, to removably couple site <NUM> to the skin of a patient after activation of device <NUM>, which separates sleeve pad <NUM> from sleeve <NUM> as site <NUM> is applied to the skin of the patient. The adhesive layer can be applied to or coupled with a bottom surface of sleeve pad <NUM>, or in another embodiment the adhesive layer can be applied to or coupled with a different surface of or coupled to site <NUM>. In <FIG>, a top surface of sleeve pad <NUM> is visible. Sleeve pad <NUM> can also comprise a finger tab <NUM>, which can be an additional layer of material or an area free of adhesive between sleeve pad <NUM> and the skin of the patient to enable the patient or a clinician to easily grasp and remove site <NUM> from the skin of the patient or otherwise hold site <NUM> via sleeve pad <NUM> with no or reduced interaction with the adhesive layer.

One, some or all of site <NUM>, site pad <NUM> and sleeve pad <NUM> can be precoupled with one another within insertion device <NUM> (i.e., combined or assembled together during manufacturing of insertion device <NUM>), or in some embodiments they can be separate components combined upon activation of device <NUM>. For example, in one embodiment site <NUM> and site pad <NUM> are precoupled with one another within insertion device <NUM> during manufacturing, and subsequently the combination is coupled with sleeve pad <NUM>, via an additional adhesive layer on a top surface of sleeve pad <NUM> and/or on a bottom surface of site pad <NUM>, only upon activation of device <NUM> to apply site <NUM>, along with site pad <NUM> and sleeve pad <NUM>, to the skin of a patient. The perimeter <NUM> of each of site <NUM>, site pad <NUM> and sleeve pad <NUM> can be a variety of shapes. As shown in <FIG>, the general perimeter <NUM> may be round, elliptical, oblong, rectangular, semi-rectangular, rounded rectangular, square, rounded square or some other shape in various embodiments. The site <NUM>, site pad <NUM> and sleeve pad <NUM> may have a combination of such perimeter shapes as well. In one embodiment, for example, site <NUM> and site pad <NUM> have generally round perimeters while sleeve pad <NUM> has a generally elliptical perimeter.

<FIG> depicts a top view of insertion device <NUM> in which cap <NUM> is secured to housing <NUM> by lock pin <NUM>, and <FIG> depicts a side sectional view of insertion device <NUM>. A subcutaneous element, such as a cannula <NUM>, extends from the bottom surface of site <NUM> at an angle greater than <NUM> degrees and less than <NUM> degrees with respect to that bottom surface. In embodiments, cannula <NUM> can be at an angle α (see <FIG>) of between about <NUM> degrees and about <NUM> degrees, such as between about <NUM> degrees and about <NUM> degrees, for example about <NUM> degrees. In other embodiments, cannula <NUM> can instead comprise a wire, filament, sensor, or other device or element configured to be inserted at least partially subcutaneously. An embodiment comprising a cannula is discussed herein by way of example only.

Site pad <NUM> and sleeve pad <NUM> each comprise an aperture <NUM> and <NUM> (see <FIG>), respectively, that enables cannula <NUM> to pass through site pad <NUM> and sleeve pad <NUM> when site <NUM> is applied to the skin of a patient. Apertures <NUM> and <NUM> can be elliptical, which can be more easily compatible with the angle of cannula <NUM>, or round or some other shape. Apertures <NUM> and <NUM> can have the same or different shapes, circumferences, relative placements on site pad <NUM> and sleeve pad <NUM>, respectively, and other features and characteristics.

<FIG> depict insertion device <NUM> in a post-manufacturing shipped state, and in an embodiment in which site <NUM> is preloaded in insertion device, and cap <NUM> is secured to housing <NUM> by lock pin <NUM> and includes tear-away band <NUM>. Cap <NUM> comprises a cap post <NUM> extending upwardly or away from an inner bottom surface of cap <NUM> at a similar angle as cannula <NUM>. Cap post <NUM> is hollow or otherwise comprises an interior channel <NUM> to house cannula <NUM> in the shipped state. The top or open end of cap post <NUM> is configured to support site <NUM>. In one embodiment, the open end of cap post <NUM> is stepped or graduated such that a first portion <NUM> of cap post <NUM> supports site <NUM> near one side or edge of site <NUM> and a second portion <NUM> of cap post <NUM> supports site <NUM> at or near its center, accommodating the relative angles between site <NUM> and cap post <NUM>. As such, in embodiments second portion <NUM> and one or both of apertures <NUM> and <NUM> are arranged to enable second portion <NUM> to pass therethrough and contact the bottom surface of site <NUM> proximate, such as adjacent to or at least partially around, cannula <NUM>. In embodiments, one or both of first and second portions <NUM> and <NUM> can be configured to engage with a corresponding portion of site <NUM> to more securely support site <NUM> within insertion device <NUM>.

Site <NUM> is also supported or held in place within insertion device <NUM> by an end portion <NUM> of cylinder hub <NUM> and trigger rib <NUM> of sleeve <NUM>. End portion <NUM> and trigger rib <NUM> can abut and/or support at least a portion of a central hub <NUM> of site <NUM>. In one embodiment, end portion <NUM> can further be configured to abut and/or support at least a portion of the top surface of site <NUM>. Thus, like the end of cap post <NUM> having first and second portions <NUM> and <NUM>, end portion <NUM> of cylinder hub <NUM> is also configured to support site <NUM> in an orientation in which the top and bottom surfaces of site <NUM> are neither parallel nor perpendicular with the sidewalls of housing <NUM> and cap <NUM>. The bottom surface of site <NUM> is generally parallel to the top surface of sleeve pad <NUM>. In an embodiment shown in <FIG>, site <NUM> is generally parallel with an end portion <NUM> of cap <NUM>, wherein end portion <NUM> is not perpendicular with the sidewall of cap <NUM> and is not parallel with an end surface of housing <NUM>. In general, the angle between end portion <NUM> and the sidewall of cap <NUM>, as well as the angle between the top and bottom surfaces of site <NUM> and the sidewalls of cap <NUM> and housing <NUM>, is similar to the angle at which cannula <NUM> extends from the bottom surface of site <NUM> (i.e., an angle between about <NUM> degrees and about <NUM> degrees, such as between about <NUM> degrees and about <NUM> degrees, for example about <NUM> degrees, in various embodiments). In some embodiments, end portion <NUM> of cap <NUM> is not parallel to the bottom surface of site <NUM> and the angle between end portion of <NUM> of cap <NUM> and the sidewalls of housing <NUM> and cap <NUM> may be a different angle, such as a right angle.

Referring also to <FIG>, cylinder hub <NUM> is generally hollow and comprises a shoulder portion <NUM> and a body portion <NUM>. Shoulder portion <NUM> can have a generally ovular or oblong cross-section, while body portion <NUM> also can be generally ovular, oblong or round. In one embodiment, body portion <NUM> tapers slightly (i.e., the cross-section diameter decreases) between shoulder portion <NUM> and a distal end of cylinder hub <NUM>. Shoulder portion <NUM> can comprise two tabs <NUM> configured to engage with shoulders <NUM> (see <FIG>) of housing <NUM> to couple cylinder hub <NUM> and housing <NUM> with at least a portion of shoulder portion <NUM> abutting an inner surface of an end of housing <NUM>. In one embodiment, and referring also to <FIG>, an internal top surface <NUM> of housing <NUM> can comprise a standing circular rib <NUM> configured to interface with shoulder portion <NUM> to hold shoulder portion in place within housing <NUM>. Housing <NUM> also comprises guide ribs <NUM> and sleeve tabs <NUM>.

Cylinder hub <NUM> further comprises apertures <NUM> (see <FIG>) extending from a first end of cylinder hub <NUM>, through shoulder portion <NUM> via internal guides <NUM> that form a channel in shoulder portion <NUM> to connect with apertures <NUM> formed in body portion <NUM>. Apertures <NUM> are configured to guide needle hub <NUM> within cylinder hub <NUM> and extend from shoulder portion <NUM> to about a midpoint of body portion <NUM>. Apertures <NUM> are formed opposite each other, on opposing sides of cylinder hub <NUM>.

Body portion <NUM> comprises an aperture <NUM> configured to interact with a corresponding tab on needle hub <NUM>. Body portion <NUM> also comprises a needle guide <NUM> and previously mentioned end portion <NUM> that abuts site <NUM> as discussed above.

Referring to <FIG>, <FIG>, needle hub <NUM> is configured to be slidably arranged within the hollow cylinder hub <NUM> (see <FIG>). Needle hub <NUM> comprises tabs <NUM> configured to slide within guides <NUM> and apertures <NUM> of cylinder hub <NUM> (see <FIG>). Tabs <NUM> also can interact with biasing element <NUM> (see <FIG>), such as to compress biasing element toward site <NUM> (as depicted in <FIG>). Needle hub <NUM> further comprises needle retaining portion <NUM> and snap arm <NUM>. During use and operation, snap arm <NUM> interacts with both aperture <NUM> (see <FIG>) of cylinder hub <NUM> (to initially retain needle hub <NUM> proximate needle guide <NUM>) and trigger rib <NUM> (see <FIG>) (to disengage snap arm <NUM> from aperture <NUM> to cause needle hub <NUM> and needle <NUM> to be retracted within housing <NUM>.

Referring to <FIG>, <FIG>, <FIG>, <FIG>, site <NUM> is depicted, along with septum <NUM> and site cap <NUM>. Septum <NUM> is configured to fit within central hub <NUM> and facilitate fluid communication between needle <NUM> and cannula <NUM> in use. As can be seen in <FIG>, septum <NUM> is asymmetrical, having a slanted lower portion <NUM>. An inner surface <NUM> of central hub <NUM> is correspondingly slanted to accommodate septum <NUM>. Site cap <NUM> fits on central hub <NUM> over septum <NUM> to secure septum <NUM> therewithin. In use and operation of insertion device <NUM>, needle <NUM> enters site <NUM> via a side aperture <NUM> formed in central hub <NUM>. Needle <NUM> passes through septum <NUM> within central hub <NUM> and exits site <NUM> via needle aperture <NUM>. As needle <NUM> passes through needle aperture <NUM>, needle <NUM> enters cannula <NUM> (not shown in <FIG> and <FIG>) to insert cannula into the skin of a patient as site <NUM> is applied to the skin of the patient. Needle <NUM> is then removed and retracted within insertion device <NUM>, as will be discussed more below.

Referring to <FIG>, a septum <NUM> is depicted from various perspectives, for use in a site <NUM>. Specifically, the views shown are side, bottom, back side, front side, and multiple perspective views, respectively. As shown, septum <NUM> is generally made up of a main body portion <NUM>, an upper protrusion <NUM>, and a slanted lower portion <NUM>. Main body portion <NUM> is generally a vertically disposed, cylindrical member which surrounds a cylindrical cavity <NUM>. Extending vertically from main body portion <NUM> is a tapered, generally conical, upper protrusion <NUM>. Further, the main body portion <NUM> is merged with a smaller diameter, generally cylindrical, slanted lower portion <NUM> that extends across the bottom of the main body portion <NUM> in an angled manner. Lower portion <NUM> has a planar, angled face <NUM> at its lower end. This angled face <NUM> contains an arch shaped aperture <NUM> that provides a channel <NUM> that extends partially through the slanted lower portion <NUM> and merges with the cylindrical cavity <NUM> of the main body portion. Further, the slanted lower portion <NUM> further contains a lower aperture <NUM> that provides access to the cylindrical cavity <NUM> from the bottom of the septum <NUM>. This lower aperture <NUM> further provides a small recess from the bottom surface of the lower portion <NUM>.

Accordingly, the channel <NUM> formed within the septum <NUM> provides angled access for a cannula <NUM> that is inserted through a site <NUM> at various angles. The contours of the arch shaped aperture <NUM> and channel <NUM> provide a versatile and functional passage and arrangement for cannula insertion. Accordingly, the when the cannula <NUM> is inserted through the aperture <NUM>, wall <NUM>, and channel <NUM> of lower portion <NUM>, a convenient seal is made possible by the septum <NUM>.

Sleeve <NUM> is depicted in <FIG>. Sleeve <NUM> comprises trigger rib <NUM>. Sleeve <NUM> further comprises tabs <NUM> and guide channels <NUM>, each of which interacts with a corresponding portion of housing <NUM>: tabs <NUM> can interlock with sleeve tabs <NUM> (see <FIG>) while guide channels <NUM> can guide sleeve ribs <NUM> (see <FIG>) on each side. The ends of guide channels <NUM> can prevent further relative movement of housing <NUM> and sleeve during operation. Cylinder hub <NUM> is configured to be arranged through central aperture <NUM>, while a rib <NUM> in which central aperture <NUM> is formed can be a stop or fixing point for biasing element <NUM>, such that biasing element <NUM> is arranged between tabs <NUM> of needle hub <NUM> and rib <NUM> in at least one operational state of insertion device <NUM>.

Biasing element <NUM> can comprise a spring, such as a coil spring, in embodiment. In other embodiments, some other type or form of biasing element can be used. As discussed below, biasing element <NUM> is compressed during application of site <NUM>, and release of the compression retracts needle <NUM> during use and operation of insertion device <NUM>.

Referring to <FIG>, insertion device <NUM> is depicted in a "triggered" state. To achieve the "triggered" state from the "shipped" state depicted in <FIG>, lock pin <NUM>, tear-away band <NUM> and cap <NUM> are removed. Insertion device <NUM> is placed on the skin of the patient, with the open bottom portion of sleeve <NUM> against and substantially parallel with the skin of the patient. Housing <NUM> is pushed toward the skin of the patient while sleeve <NUM> remains generally stationary with respect to the skin of the patient. This advancement of housing <NUM> causes site <NUM> and cannula <NUM>, cylinder hub <NUM>, needle hub <NUM> and needle <NUM> to advance toward the skin of the patient until site pad <NUM> is in contact with sleeve pad <NUM> that is already in contact with the skin of the patient and needle <NUM> has inserted cannula <NUM> into the skin of the patient. At the same time, biasing element <NUM> is compressed. This is generally the state depicted in <FIG>, although sleeve pad <NUM> is not specifically depicted in this view.

In <FIG>, cannula <NUM> would be inserted into the skin of a patient if so applied, and cannula <NUM> would enter the skin of the patient at an angle between <NUM> degrees and <NUM> degrees, as discussed above. In embodiments, cannula <NUM> is about <NUM> to about <NUM> long, such as about <NUM> long in one example embodiment and such as about <NUM> in another example embodiment. The length of cannula <NUM> can vary in other embodiments. Another advantage of the angled insertion of cannula <NUM> can be an increased resistance to potential escape of the medicament being infused, which might occur if a portion of the medicament were to follow the exterior surface of cannula <NUM> to the surface of the patient's skin. More particularly, if cannula <NUM> is inserted at an angle between <NUM> degrees and <NUM> degrees, such as about <NUM> degrees, instead of at <NUM> degrees as is conventional, cannula <NUM> can be longer, such as twice as long or more, yet penetrate to the same depth within the subcutaneous layer of the patient's skin.

Once housing <NUM>, cylinder hub <NUM> and needle hub <NUM> advance sufficiently toward the patient's skin so that snap arm <NUM> (see <FIG>) of needle hub <NUM> reaches trigger rib <NUM> (see <FIG>), trigger rib <NUM> causes snap arm <NUM> to disengage from aperture <NUM> (see <FIG>). Because biasing element <NUM> has been compressed during the movement of housing <NUM> and cylinder hub <NUM> toward the skin and relative to sleeve <NUM>, disengagement of snap arm <NUM> from aperture <NUM> by trigger rib <NUM> causes needle hub <NUM> and needle <NUM> to be retracted upwardly away from the skin within cylinder hub <NUM> and housing <NUM> by the released force of compressed biasing element <NUM>, which engages with tabs <NUM> to retract needle hub <NUM>. Insertion device is then in a "retracted" state.

Referring to <FIG>, the "retracted" state of insertion device <NUM> is depicted. Needle hub <NUM> is retracted within cylinder hub <NUM> and housing <NUM> until needle <NUM> is substantially or fully within cylinder hub <NUM>, such that it cannot be accessed or inadvertently "stick" someone after it has now been used to apply site <NUM> and insert cannula <NUM>. Biasing element <NUM> is generally relaxed, or at least less compressed than in either the "shipped" or "triggered" states.

Once site <NUM> has been applied to the skin of a patient, an infusion set can be coupled to site <NUM> to enable an infusion pump or other fluid source to deliver a fluid to the patient via site <NUM>, in an embodiment in which site <NUM> is used for infusion. Examples of infusion sets are disclosed in <CIT>, In embodiments, the set can be coupled to site <NUM> in a plurality of different relative positions (i.e., to change the side or angle from which infusion tubing of the set extends from site <NUM> to increase comfort and convenience to the patient). In one embodiment, an infusion set can be coupled to site <NUM> in at least different relative positions, such as with the needle of the set entering site <NUM> from one of four different sides spaced apart from another by about <NUM> degrees. In other embodiments, more or fewer relative coupling relationships between site <NUM> and the set are possible. Upon being coupled to site <NUM>, a needle within the set passes through a side of central hub <NUM> and pierces septum <NUM>, establishing fluid communication between the needle (and medical tubing coupled thereto via the rest of the set, such as from an infusion pump) and cannula <NUM>.

In still other embodiments, devices other than infusion sets and tubing can be coupled to site <NUM>. In embodiments, this coupling can be mechanical, electrical, communicative or some combination of these coupling modalities. A set or other type of mechanical coupler can be used in embodiments, or a set can be omitted. To accommodate a variety of different coupling types and configurations, the configuration of site <NUM> can vary in embodiments, as can the configuration, size and orientation of some or all of the components of insertion device <NUM>. For example, in embodiments the configuration of portions of sleeve <NUM>, cylinder hub <NUM> and/or needle hub <NUM>, which can interact with site <NUM> to abut and/or support site <NUM> within insertion device <NUM>, can vary from those depicted as the configuration or type of payload (e.g., site <NUM>) of insertion device <NUM> varies. In various embodiments, however, insertion device <NUM> can be used to apply, including subcutaneously, at least a portion of a site or other device at an angle between <NUM> degrees and <NUM> degrees to the skin of a patient. In some embodiments, the insertion needle passageway through the site can always be used for attachment of a set buckle to the site after placement onto the skin of a patient.

Additionally, site <NUM> can comprise additional elements or devices that communicate, cooperate or support the subcutaneous element or that otherwise provide a desired function. For example, in embodiments site <NUM> can comprise a radio-frequency identification (RFID) tag, chip, circuit, memory, sensor, light-emitting diode (LED), user interface, or other device or feature. These various devices and features can collect data, such as via the subcutaneous element or independently, and provide information to a user, clinician, other caregiver, computer or system. In still other embodiments, one or more components of site <NUM> can communicate with an external device, such as a meter, smartphone, smart watch, tablet, handheld or bodyworn computer or device, laptop, network, computer terminal, data reader or virtually any other device. The communications can be wired or wireless and can utilize one or more communication techniques including WIFI, BLUETOOTH, near- or far-field communications, or other techniques.

<FIG> provides a cross-sectional side view of one embodiment of a site <NUM> depicted in a similar orientation to site <NUM> shown in <FIG>. Site <NUM> provides a sensor <NUM>, such as an analyte sensor, in a multi-surfaced, generally disc-shaped housing <NUM>. The sensor <NUM> is shown with a proximal portion <NUM> as well as a sensing filament <NUM> extending from the generally flat bottom surface <NUM> of the housing <NUM> to distal portion <NUM> at an angle β. In some embodiments, angle β will be about <NUM> degrees. The angled, sensing filament <NUM> has advantages over a perpendicular filament as it can be twice as long and contact much more tissue in certain embodiments. In addition to one or more sensors <NUM>, housing <NUM> may include a printed circuit board <NUM> and associated electronics. In certain embodiments, sensors <NUM> of this type may be used for monitoring analytes, such as glucose, in bodily fluids (blood, interstitial fluid, or others) where the sensing filament is positioned below the skin surface and monitoring is in vivo.

Housing <NUM> is shown with a generally planar top housing surface <NUM> and an angled side housing surface <NUM> along at least one side. The remaining side surface(s) <NUM> may be perpendicular to the top housing surface <NUM> or may gradually slope down to the bottom surface <NUM>, as depicted in <FIG>. The angled side surface <NUM> of the housing, makes it possible to appropriately fit the site <NUM> within the confines of an angled insertion device <NUM> (or <NUM>) having a housing <NUM> and sleeve <NUM> disposed similar to the arrangement depicted in <FIG>. In some embodiments the angled side surface is oriented at an angle generally consistent with the sensing filament <NUM> or other subcutaneous element. Further, the partially angled housing surface configuration can permit mounting and delivery of site components which have a desired cross section, such as a circular cross-section. This cross-section can match a desired cross section of a sleeve <NUM> of an insertion device <NUM>, for example. Top housing surface <NUM> contains a clearance aperture <NUM>. This aperture <NUM> provides an angled hole for passage of an introducer needle <NUM>. The housing and sensor arrangement of the site <NUM> accordingly permit a sensor that may be introduced and secured by angled introduction of a needle <NUM> and sensing filament <NUM>.

Another type of site that may be provided by an insertion device is a "patch pump". For purposes of this application, "patch pumps" refer to small infusion pumps that can be adhered directly to the skin for wear. Such patch pumps can be used to infuse a variety of fluids or medicaments. Patch pumps include insulin pumps which can provide insulin to diabetic users; however, their usefulness can extend beyond insulin delivery to the delivery of other medicaments. In some embodiments, patch pumps involve no tubing, readily adhere to the body, are small, lightweight, completely or partially disposable, and are capable of being worn and manipulated discreetly under clothing. Some patch pumps are controlled wirelessly by a separate controller.

<FIG> and the corresponding description generally depict patch pumps (i.e. sites <NUM>) and corresponding features of an insertion device <NUM>. This insertion device <NUM> should be understood to generally operate in a corresponding manner to insertion device <NUM> with some variations necessary for the accommodation of the particular dimensions and parameters of the site <NUM> rather than a site <NUM>. These differences include a different retention arrangement of the site <NUM> that is discussed in further detail in connection with <FIG>. While the details of a patch pump site <NUM> are more specifically addressed below, a sensor site <NUM> of similar housing shapes and/or arrangements should be understood to be fully disclosed by this description as well.

<FIG> is a top view of a site or elliptical patch with a multi-surfaced housing <NUM> according to an embodiment. The elliptical patch pump <NUM> includes a generally planar top housing surface <NUM> and an angled side housing surface <NUM>. The patch pump <NUM> is shaped and sized such that it can be applied by an angled insertion device <NUM> with a circular cross section across its sleeve <NUM>. Patch pumps <NUM> of a variety of shapes and sizes are possible, but must be appropriately shaped to fit within the cross section of the desired angled insertion device <NUM>.

<FIG> is a top view of a site constituting a rectangular patch pump 380a with a multi-surfaced housing 312a according to an embodiment. The rectangular patch pump 380a includes a generally planar top housing surface 324a and an angled side housing surface 326a. The patch pump 380a is shaped and sized such that it can be applied by an angled insertion device <NUM> with a square cross section across its sleeve <NUM>.

Although not depicted in <FIG>, a patch pump <NUM> can generally contain an adhesive pad across its bottom surface when deployed on a user in certain embodiments, which will extend beyond and around the perimeter of the housing <NUM>. Adhesive pads of this type can be adapted for use over periods of long term wear in some embodiments.

<FIG> sets forth a schematic diagram of the internal components of a patch pump <NUM> inside housing <NUM>. The housing <NUM> can be watertight or otherwise impermeably sealed in various embodiments. The patch pump <NUM> generally contains a fluid reservoir <NUM>, a drive mechanism <NUM>, a power supply <NUM>, electronic circuitry <NUM> and an angled access cannula insertion system <NUM>. The components are generally coupled with one another, but do not require tubes or similar components subject to occlusion or similar malfunction in certain embodiments. In general, fluid reservoir <NUM> can hold a limited supply of insulin or other medicament. In certain embodiments, the fluid reservoir <NUM> may be replaceable. However, the fluid reservoir <NUM>, or entire patch pump <NUM>, may be disposable once the fluid reservoir <NUM> is used. Drive mechanism <NUM> can comprise a variety of types of pumping mechanisms sized for the patch pump and will generally be controlled by electric circuitry <NUM>. The electronic circuitry <NUM> can program fluid delivery and communications. Electronic circuitry <NUM> can include a controller or can be controlled wirelessly by a controller located outside the pump housing <NUM>. The power supply <NUM> can comprise one or more batteries in various embodiments. The angled access cannula insertion system <NUM> provides an access passageway and features which enable safe application of the patch pump <NUM> to a user. This cannula insertion system <NUM> can include all insertion related features and passages of the patch pump <NUM> and can be better understood in the subsequent figures and discussion of the application.

Referring to <FIG>, a side cross-sectional view of an insertion device <NUM> in a post-manufacturing "shipped" state, for use applying a preloaded patch pump <NUM>. This view is presented as an alternate cross-sectional view of <FIG>. A subcutaneous element, such as a cannula <NUM>, extends from the bottom surface of patch pump <NUM> at an angle greater than <NUM> degrees and less than <NUM> degrees with respect to that bottom surface. In embodiments, cannula <NUM> can be at an angle β (see <FIG>) of between about <NUM> degrees and about <NUM> degrees, such as between about <NUM> degrees and about <NUM> degrees, for example about <NUM> degrees.

Site pad <NUM> and sleeve pad <NUM> each comprise an aperture that enables cannula <NUM> to pass through site pad <NUM> and sleeve pad <NUM> when patch pump <NUM> is applied to the skin of a patient. Patch pump <NUM> is preloaded in insertion device <NUM>, and cap <NUM> is secured to housing <NUM> by lock pin <NUM> and includes tear-away band <NUM>. In some embodiments, as shown in <FIG>, the top or open end of cap post <NUM> is configured to support patch pump <NUM> with stepped or graduated features. In some embodiments, no cap post <NUM> will be present for support of a patch pump <NUM>. In both embodiments, with or without a cap post <NUM>, support for the patch pump <NUM> can also rely on an arrangement of retention fingers <NUM> that can extended from the end portion <NUM> of cylinder hub <NUM> into the attachment aperture <NUM> of the patch pump <NUM>.

End portion <NUM> of cylinder hub <NUM> is also configured to support patch pump <NUM> in an orientation in which the top surface <NUM> and bottom surface <NUM> of patch pump <NUM> are neither parallel nor perpendicular with the sidewalls of housing <NUM> and cap <NUM>. In an embodiment shown in <FIG>, the bottom surface <NUM> of patch pump <NUM> is generally parallel with an end portion <NUM> of cap <NUM>, wherein end portion <NUM> is not perpendicular with the sidewall of cap <NUM> and is not parallel with an end surface of housing <NUM>. In general, the angle between end portion <NUM> and the sidewall of cap <NUM>, as well as the angle between the top and bottom surfaces of patch pump <NUM> and the sidewalls of cap <NUM> and housing <NUM>, is similar to the angle at which cannula <NUM> extends from the bottom surface of patch pump <NUM> (i.e., an angle between about <NUM> degrees and about <NUM> degrees, such as between about <NUM> degrees and about <NUM> degrees, for example about <NUM> degrees, in various embodiments). In some embodiments, end portion <NUM> of cap <NUM> is not parallel to the bottom surface of patch pump <NUM> and the angle between end portion <NUM> of cap and the sidewalls of housing <NUM> and cap <NUM> may be a different angle, such as a right angle.

<FIG> is a side cross-sectional view of an insertion device depicted in a "triggered" state for applying a patch pump <NUM>. This is presented as an alternate cross-sectional view of <FIG>. In this state, as shown, lock pin <NUM>, tear-away band <NUM> and cap <NUM> have been removed and insertion device <NUM> has been placed on the skin of the patient. Specifically, the open bottom portion of sleeve <NUM> has been placed against and parallel with the skin of the patient. Housing <NUM> has been pushed toward the skin while sleeve <NUM> remains generally stationary with respect to the skin. Patch pump <NUM>, cannula <NUM>, cylinder hub <NUM>, needle hub <NUM> and needle <NUM> have been advanced toward the skin until patch pump <NUM> is in contact with the skin and needle <NUM> has inserted cannula <NUM> into the skin. This arrangement would insert a cannula <NUM> into the skin of the patient at an angle between <NUM> degrees and <NUM> degrees.

Once housing <NUM>, cylinder hub <NUM> and needle hub <NUM> advance sufficiently toward the skin that snap arm <NUM> of needle hub <NUM> reaches trigger rib <NUM>, trigger rib <NUM> causes snap arm <NUM> to disengage from aperture <NUM>. Because biasing element <NUM> has been compressed during the movement of housing <NUM> and cylinder hub <NUM> toward the skin and relative to sleeve <NUM>, disengagement of snap arm <NUM> from aperture <NUM> by trigger rib <NUM> causes needle hub <NUM> and needle <NUM> to be retracted upwardly away from the skin within cylinder hub <NUM> and housing <NUM> by the released force of compressed biasing element <NUM>, which engages with tabs <NUM> (See <FIG>) to retract needle hub <NUM>. Insertion device <NUM> is then in a "retracted" state.

<FIG> is a side cross-sectional view of an insertion device <NUM> in a "retracted" state using a patch pump <NUM>. This view is presented as an alternate cross-sectional view of <FIG>. Needle hub <NUM> is retracted within cylinder hub <NUM> and housing <NUM> until needle <NUM> is substantially or fully within cylinder hub <NUM>, such that it cannot be accessed or inadvertently "stick" someone after it has now been used to apply patch pump <NUM> and insert cannula <NUM>. Biasing element <NUM> is generally relaxed, or at least less compressed than in either the "shipped" or "triggered" states.

Once patch pump <NUM> has been applied to the skin of a patient, the needle <NUM> is retracted, leaving the cannula <NUM> of the patch pump <NUM> inserted in the desired patient location. As the needle <NUM> is retracted from the passageway in the pump, retention fingers <NUM> of the cylinder hub <NUM> are permitted to disengage from the patch pump <NUM>. This disengagement results in the patch pump <NUM> being separated from the rest of the insertion device <NUM>. Accordingly, retraction of the needle allows the retention fingers <NUM> to move inward during removal. Operation of the retention fingers <NUM> is described in greater detail in <FIG> and the related disclosure.

<FIG> are side cross-sectional views of a patch pump retention arrangement with the cylinder hub <NUM> prior to and during needle retraction, respectfully. In <FIG>, patch pump <NUM> having a housing <NUM> with a top housing surface <NUM>, angled side surface <NUM>, and bottom surface <NUM> is shown. The top housing surface <NUM> contains an attachment aperture <NUM> which provides an angled passageway <NUM> through the housing <NUM> at an angle that is generally parallel to that of the angled side surface <NUM>. Accordingly, in some embodiments the angled side surface <NUM> is oriented at an angle generally consistent with the cannula <NUM> or other subcutaneous element. The angled passageway <NUM> provides space for a needle <NUM> to pass through the housing <NUM> and a location for securing the patch pump <NUM> to the cylinder hub <NUM> of the insertion mechanism <NUM> until the needle <NUM> is retracted.

The angled passageway <NUM> begins to extend inward from the attachment aperture <NUM> in an angled manner with a smooth surface diameter. Partially into the angled passageway <NUM> an annular constriction <NUM> protrudes inward from the perimeter before the angled passageway <NUM> again widens to a section <NUM> of smooth diameter that houses a self-sealing septum <NUM>. The angled passageway <NUM> is reduced to a final, narrow diameter passage <NUM> leading to the bottom housing surface <NUM>, out of which cannula <NUM> extends in an angled manner from the housing <NUM>.

In <FIG>, features of the cylinder hub <NUM>, consisting of retention fingers <NUM> (also interchangeably and more specifically identified individually as 350a, 350b. etc. in the figures and description), extend into the angled passageway <NUM>. In the embodiment shown, only a first retention finger 350a and a second retention finger 350b are present, surrounded by a central passageway <NUM>. In other embodiments, a greater number of retention fingers <NUM> can be present which are radially surrounded by the central passageway <NUM> in a spaced-apart manner. The retention fingers <NUM> have a generally smooth inner surface <NUM> partially surrounding the central passageway <NUM> which is in adjacent contact with the surface of the needle <NUM> extending therethrough. The outer surface portion <NUM> of the retention fingers <NUM> is generally smooth for a distance as it extends from the cylinder hub <NUM> into the contoured angled passageway <NUM> of the housing <NUM>. A recessed section <NUM> is present partway along the outer surface <NUM> as well as an outwardly extending tab <NUM> extends toward the passageway wall at or near the distal end of the retention finger <NUM>. In the initial retained position, the retention fingers <NUM> are engaged within the angled passageway <NUM> such that the outwardly extending tab <NUM> is located in the wider section <NUM> of the angled passageway <NUM> beyond the annular constriction <NUM>. In this position, the annular constriction <NUM> projects inwardly toward recessed section <NUM> of the retention finger <NUM>. The retention fingers <NUM> are generally held in place when needle <NUM> extends through the central passageway <NUM> as the needle <NUM> interferes with the ability of the retention fingers <NUM> to flex inwardly so that the annular constriction <NUM> and outwardly extending tabs <NUM> interfere with movement past each other.

<FIG> shows the release of the patch pump <NUM> upon retraction of the needle <NUM>. Once the needle <NUM> has carried out angled insertion into a patient to properly place cannula <NUM> into the desired location, the needle <NUM> is retracted through the cannula <NUM>, self-sealing septum <NUM>, and through the central passageway <NUM> between the retention fingers <NUM>. As the needle <NUM> is withdrawn from the central passageway <NUM>, the retention fingers <NUM> are free to flex inwardly into the space of the central passageway <NUM> so that the annular constriction <NUM> no longer interferes with movement of the tabs <NUM>. Accordingly, the patch pump <NUM> is freely released from the retention fingers <NUM> and remains deployed on a patient. This release enables the remaining features of the insertion mechanism <NUM> to be separated from the patch pump <NUM>. Medicament reaches the top end of the cannula <NUM> through a cavity, not shown, below self-sealing septum <NUM> that is in fluid communication with fluid reservoir <NUM>.

<FIG> is a perspective view depicting one embodiment of a pair of retention fingers 350a and 350b that could be used as part of the end portion <NUM> of the cylinder hub <NUM>. Each retention finger 350a and 350b has a smooth inner surface <NUM> and a projecting tab <NUM> extending outwardly at the distal end <NUM>. The tab portion consists of a first projecting flat surface <NUM>, a flat end surface <NUM>, and an angled flat surface <NUM> extending between the surfaces <NUM> and <NUM>. Various shapes and sizes may be used for tabs to provide secure engagement within the contoured passageway. In general, however, rigid outward extension of the tabs <NUM> is held in place and is made possible based on interference of a central needle <NUM>, when present, with the inside smooth surfaces <NUM> of the retention fingers 350a and 350b.

It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with an enabling disclosure for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the subject matter hereof as set forth in the appended claims.

The embodiments above are intended to be illustrative and not limiting. Additional embodiments are within the claims. Although subject matter hereof has been described with reference to particular embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the subject matter.

Claim 1:
An insertion device (<NUM>) comprising:
a housing (<NUM>) comprising a first end;
a sleeve (<NUM>) slidably arranged at least partially in the housing (<NUM>);
a cylinder hub (<NUM>) at least partially arranged in the sleeve (<NUM>) and the housing (<NUM>) and comprising a shoulder portion (<NUM>) and a body portion (<NUM>), the shoulder portion (<NUM>) proximate to the first end of the housing (<NUM>);
a needle hub (<NUM>) slidably arranged in the cylinder hub (<NUM>) and comprising a needle (<NUM>); and
a site (<NUM>) comprising a patient-side surface, a central hub (<NUM>) having a side aperture (<NUM>) formed therein, and a subcutaneous element (<NUM>), the subcutaneous element (<NUM>) coupled to the site (<NUM>) at an angle greater than <NUM> degrees and less than <NUM> degrees with respect to the patient-side surface, the site (<NUM>) arranged within the housing (<NUM>) such that the needle (<NUM>) can pass through the side aperture (<NUM>) of the central hub (<NUM>) to enter the subcutaneous element (<NUM>) at the angle.