Patent Description:
Certain diseases or conditions may be treated, according to modem medical techniques, by delivering a medication or other substance to the body of a user, either in a continuous manner or at particular times or time intervals within an overall time period. For example, diabetes is commonly treated by delivering defined amounts of insulin to the user at appropriate times. Some common modes of providing insulin therapy to a user include delivery of insulin through manually operated syringes and insulin pens. Other modem systems employ programmable fluid infusion devices (e.g., insulin pumps) to deliver controlled amounts of insulin to a user. In certain instances, these fluid infusion devices require an insertion set, such as an infusion set, to be coupled to the body of a user for the delivery of the insulin. Generally, the infusion set is coupled to the fluid infusion device via hollow tubing, which provides a fluid flow path from the fluid infusion device to the user. Typically, the infusion set requires a portion of a cannula, for example, to be inserted under the skin of the user to deliver the controlled amounts of insulin from the fluid infusion device to the user via the infusion set.

In certain instances, the cannula inserted under the skin of the user may be composed of a polymer-based material. The polymer-based material, however, is typically not rigid to provide comfort to the user, but the decreased rigidity may result in bending of the cannula during wear by the user. Further, in certain instances, the cannula inserted under the skin of the user may be composed of a rigid material. In these instances, during the wearing of the infusion set by the user, when the hollow tubing is caught on an object, a strain is imparted directly to the infusion set, which may cause the metal cannula to advance into the skin of the user. This may be uncomfortable to the user. <CIT> discloses an infusion set for use with a fluid infusion device having a fluid reservoir, the infusion set being for removable attachment to the skin of a user, and comprising an outer housing surrounding an inner housing bearing an infusion cannula, wherein the inner housing is decoupled from the outer housing.

Accordingly, it is desirable to provide an infusion set having a pivoting metal cannula and strain relief for coupling to a user to deliver a fluid from a fluid infusion device to the user. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

The invention comprises an infusion set according to claim <NUM>. Additional features of preferred embodiments are defined in the dependent claims.

According to various embodiments, provided is an infusion set for use with a fluid infusion device having a fluid reservoir. The infusion set includes a cannula that provides a fluid flow path and a first housing including an articulation member coupled to the cannula. The articulation member is pivotable relative to the first housing to move the cannula relative to the first housing. The first housing is coupled to a fluid supply line to provide a fluid to the cannula, and the fluid supply line is to be coupled to the fluid reservoir to receive the fluid. The infusion set includes a second housing uncoupled from the first housing that surrounds the first housing and receives a portion of the fluid supply line.

Also provided according to various embodiments is an infusion set for use with a fluid infusion device having a fluid reservoir. The infusion set includes a cannula that provides a fluid flow path and a first housing including an articulation member coupled to the cannula. The articulation member is pivotable relative to the first housing to move the cannula relative to the first housing. The first housing is coupled to a fluid supply line to provide a fluid to the cannula, and the fluid supply line is to be coupled to the fluid reservoir to receive the fluid. The infusion set includes a second housing uncoupled from the first housing that surrounds the first housing. The second housing has a plurality of retaining flanges that cooperate to receive a portion of the fluid supply line such that the portion of the fluid supply line is positioned about a circumference of the second housing.

Further provided according to various embodiments is an infusion set for use with a fluid infusion device having a fluid reservoir. The infusion set includes a metal cannula that provides a fluid flow path and a first housing including an articulation member coupled to the cannula. The articulation member is pivotable relative to the first housing to move the cannula relative to the first housing. The first housing is coupled to a fluid supply line to provide a fluid to the cannula, and the fluid supply line is to be coupled to the fluid reservoir to receive the fluid. The infusion set includes a second housing uncoupled from the first housing that surrounds the first housing. The second housing has a plurality of retaining flanges that cooperate to receive a portion of the fluid supply line such that the portion of the fluid supply line is positioned about a circumference of the second housing. The infusion set includes a coupling device to removably couple the infusion set to an anatomy. The coupling device includes an adhesive layer having a plurality of pedals that extend radially outward from a central portion. The first housing and the second housing are each coupled to the coupling device.

Certain terminology may be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as "top", "bottom", "upper", "lower", "above", and "below" could be used to refer to directions in the drawings to which reference is made. Terms such as "front", "back", "rear", "side", "outboard", and "inboard" could be used to describe the orientation and/or location of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms "first", "second", and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.

As used herein, the term "axial" refers to a direction that is generally parallel to or coincident with an axis of rotation, axis of symmetry, or centerline of a component or components. For example, in a cylinder or disc with a centerline and generally circular ends or opposing faces, the "axial" direction may refer to the direction that generally extends in parallel to the centerline between the opposite ends or faces. In certain instances, the term "axial" may be utilized with respect to components that are not cylindrical (or otherwise radially symmetric). For example, the "axial" direction for a rectangular housing containing a rotating shaft may be viewed as a direction that is generally parallel to or coincident with the rotational axis of the shaft. Furthermore, the term "radially" as used herein may refer to a direction or a relationship of components with respect to a line extending outward from a shared centerline, axis, or similar reference, for example in a plane of a cylinder or disc that is perpendicular to the centerline or axis. In certain instances, components may be viewed as "radially" aligned even though one or both of the components may not be cylindrical (or otherwise radially symmetric). Furthermore, the terms "axial" and "radial" (and any derivatives) may encompass directional relationships that are other than precisely aligned with (e.g., oblique to) the true axial and radial dimensions, provided the relationship is predominately in the respective nominal axial or radial direction. As used herein, the term "transverse" denotes an axis that crosses another axis at an angle such that the axis and the other axis are neither substantially perpendicular nor substantially parallel.

The following description generally relates to an infusion set of the type used in treating a medical condition of a user. The infusion set infuses a fluid into a body of the user. The non-limiting examples described below relate to an infusion set used in the treatment of diabetes, although embodiments of the disclosed subject matter are not so limited. Accordingly, the infused medication fluid is insulin in certain embodiments. In alternative embodiments, however, many other fluids may be administered through infusion such as, but not limited to, disease treatments, drugs to treat pulmonary hypertension, iron chelation drugs, pain medications, anti-cancer treatments, medications, vitamins, hormones, or the like. For the sake of brevity, conventional features and characteristics related to infusion system operation, insulin pump and/or infusion set operation, fluid reservoirs, and fluid syringes may not be described in detail here. Examples of infusion pumps and/or related pump drive systems used to administer insulin and other medications may be of the type described in, but not limited to: <CIT> and <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>;<CIT>;<CIT>; <CIT>; <CIT>; <CIT>;<CIT>; <CIT>;<CIT>; and <CIT>.

<FIG> is a perspective view of an exemplary embodiment of a fluid infusion system <NUM>. The fluid infusion system <NUM> includes two main components: a fluid infusion device <NUM> (e.g., an insulin pump) and an infusion set <NUM>, which is coupled to the fluid infusion device <NUM> as depicted in <FIG>. In one example, the infusion set <NUM> includes, without limitation: a hollow fluid supply line or tube <NUM>, an infusion unit <NUM> and a connector assembly <NUM>. The infusion unit <NUM> is coupled to a first end <NUM> of the tube <NUM> and the connector assembly <NUM> is coupled to a second end <NUM> of the tube <NUM>. The fluid infusion device <NUM> is carried or worn by the user, and the infusion set <NUM> terminates at the infusion unit <NUM> to enable the fluid infusion device <NUM> to deliver fluid to the body of the user via the tube <NUM>. Thus, the infusion unit <NUM> is coupled to the body of the user, as described in more detail below. The fluid infusion device <NUM> may leverage a number of conventional features, components, elements, and characteristics of existing fluid infusion devices. For example, the fluid infusion device <NUM> may incorporate some of the features, components, elements, and/or characteristics described in <CIT> and <CIT>.

It should be noted that the fluid infusion device <NUM> illustrated herein is merely exemplary, as any suitable fluid infusion device can be employed with the infusion set <NUM>.

The fluid infusion device <NUM> accommodates a fluid reservoir (hidden from view in <FIG>) for the fluid to be delivered to the user. The tube <NUM> represents the fluid flow path that couples the fluid reservoir to the infusion unit <NUM>. When installed as depicted in <FIG>, the tube <NUM> extends from the fluid infusion device <NUM> to the infusion unit <NUM>, which in turn provides a fluid pathway to the body of the user. In certain embodiments, an in-line connector 110b is coupled between ends of the tube <NUM> to enable the user to quickly disconnect the tube <NUM> from the fluid infusion device <NUM>. For example, the in-line connector 110b may comprise a quick release in-line connector such as that associated with the Medtronic Paradigm™ Sof-set® Micro QR or Ultimate Infusion Set, commercially available from Medtronic Minimed, Inc. of Northridge, California. For the illustrated embodiment, the connector assembly <NUM> is realized as a removable reservoir cap <NUM> (or fitting) that is suitably sized and configured to accommodate replacement of fluid reservoirs (which are typically disposable) as needed. In this regard, the reservoir cap <NUM> is designed to accommodate the fluid path from the fluid reservoir to the tube <NUM>.

With reference to <FIG>, the infusion unit <NUM> of the infusion set <NUM> is shown installed onto a skin S of a user. The infusion unit <NUM> delivers fluid from the fluid reservoir associated with the fluid infusion device <NUM> (<FIG>) received through the tube <NUM> into the body of the user. In one example, with additional reference to <FIG>, the infusion unit <NUM> includes a first or outer housing <NUM>, a second or inner housing <NUM>, a biasing member <NUM> (<FIG>), an articulation member or movable needle mount <NUM>, a mount <NUM> (<FIG>), a coupling device <NUM> and a needle or metal cannula <NUM> (<FIG>). In this example, as will be discussed, the biasing member <NUM> (<FIG>) and the movable needle mount <NUM> are received within a chamber defined between the inner housing <NUM> and the mount <NUM>. It should be noted that while the infusion unit <NUM> is described herein as including the biasing member <NUM> (<FIG>), the biasing member <NUM> may be optional.

The outer housing <NUM> surrounds the inner housing <NUM> and the mount <NUM>. Generally, the outer housing <NUM> circumscribes the inner housing <NUM> and the mount <NUM>, but is not coupled to the inner housing <NUM> or the mount <NUM>. The outer housing <NUM> is uncoupled from or discrete from the inner housing <NUM> and the mount <NUM> to provide strain relief to the first end <NUM> of the tube <NUM> (<FIG>). In this regard, by being disjoined from the inner housing <NUM> and the mount <NUM>, any strain imparted to the tube <NUM> will be dissipated by the outer housing <NUM>, which reduces a likelihood of the first end <NUM> of the tube <NUM> being uncoupled from the movable needle mount <NUM>. In one example, the outer housing <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The outer housing <NUM> may be formed through molding, casting, printing, etc. The outer housing <NUM> is generally concave, however, the outer housing <NUM> may have any desired shape.

In this example, with reference to <FIG>, the outer housing <NUM> includes a central bore <NUM>, an annular hub <NUM> and a plurality of retaining flanges <NUM>. The central bore <NUM> is defined through the hub <NUM> of the outer housing <NUM> so as to extend along an axis A. The central bore <NUM> is sized to surround the inner housing <NUM> and the mount <NUM>. In one example, the central bore <NUM> includes a notch <NUM>. The notch <NUM> is defined through a perimeter or circumference 144a of the central bore <NUM> and is defined so as to extend radially outward from the axis A. The notch <NUM> provides clearance for the tube <NUM> as it exits the movable needle mount <NUM>.

The hub <NUM> may be coupled to the needle hub <NUM> to install the infusion unit <NUM> on the user. In one example, the hub <NUM> surrounds the central bore <NUM> and is interconnected to each of the plurality of retaining flanges <NUM>. The plurality of retaining flanges <NUM> are spaced apart about a perimeter or circumference of the hub <NUM>. In one example, each of the plurality of retaining flanges <NUM> is separated by a respective one of a plurality of slots <NUM> defined from an outer periphery or perimeter 130a of the outer housing <NUM> to the hub <NUM>. In one example, the outer housing <NUM> includes <NUM> retaining flanges <NUM>, however, the outer housing <NUM> may include any number of retaining flanges, such as <NUM> to <NUM>. Each of the retaining flanges <NUM> includes a flange <NUM> and a tab <NUM>. The flange <NUM> includes a pair of sidewalls <NUM> and a base <NUM>. The pair of sidewalls <NUM> are coupled to the hub <NUM> and extend outwardly from the hub <NUM> at an angle toward the outer perimeter 130a of the outer housing <NUM>. The pair of sidewalls <NUM> interconnect the hub <NUM> and the base <NUM>. The base <NUM> is substantially planar or flat, and is coupled to the coupling device <NUM>. Each of the flanges <NUM> is substantially the same, except for the flange 156a. A base 162a of the flange 156a has an increased thickness, which enables a cutout <NUM> to be defined through the base 162a. The cutout <NUM> enables a portion of the tube <NUM> to pass through the flange 156a (<FIG>). The tab <NUM> extends axially from the hub <NUM>. The tab <NUM> cooperates with the flange <NUM> to retain the tube <NUM> when the tube <NUM> is coupled to the movable needle mount <NUM>. In this regard, due to the angle of the pair of sidewalls <NUM>, a retaining recess <NUM> is defined between the base <NUM> and the tab <NUM>. With reference to <FIG>, the retaining recess <NUM> receives a portion of the tube <NUM> to secure the tube <NUM> to the outer housing <NUM>. Generally, the plurality of retaining flanges <NUM> cooperate to enable the tube <NUM> to be positioned about a circumference of the outer housing <NUM> near the outer perimeter 130a of the outer housing <NUM>.

With reference back to <FIG>, the inner housing <NUM> retains the biasing member <NUM> and the movable needle mount <NUM> on the mount <NUM>. In one example, the inner housing <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The inner housing <NUM> may be formed through molding, casting, printing, etc. The inner housing <NUM> is generally concave, however, the inner housing <NUM> may have any desired shape. The inner housing <NUM> includes an outer surface <NUM>, an inner surface <NUM>, a plurality of coupling slots <NUM>, a clearance aperture <NUM> and a needle bore <NUM>.

The outer surface <NUM> is substantially smooth, and is substantially conical. The inner surface <NUM> is opposite the outer surface <NUM>. With reference to <FIG>, the inner surface <NUM> includes a biasing member clearance surface <NUM> and a first articulation surface <NUM>. With reference to <FIG>, the biasing member clearance surface <NUM> extends about a circumference of the inner housing <NUM> on the inner surface <NUM>. The biasing member clearance surface <NUM> provides space or room for the biasing member <NUM> to move between a compressed and a relaxed state during the use of the infusion unit <NUM>. Generally, the biasing member clearance surface <NUM> has a shape that corresponds to the shape of the biasing member <NUM> (<FIG>); however, the biasing member <NUM> may have any desired shape.

The first articulation surface <NUM> is spherical and concave. The first articulation surface <NUM> is defined on the inner surface <NUM> so as to be offset from a central axis A2 of the inner housing <NUM>. The central axis A2 is parallel to the vertical axis V (<FIG>). In this example, the first articulation surface <NUM> is offset from the central axis A2 toward a second end 132b of the inner housing <NUM>. Generally, the first articulation surface <NUM> extends from a first side 172a of the inner surface <NUM> to a second, opposite side 172b of the inner surface <NUM> near or adjacent to the second end 132b of the inner housing <NUM>. The first articulation surface <NUM> may include a central portion 182a with one or more ribs 182b spaced apart and extending radially outward from the central portion 182a. In this example, the one or more ribs 182b cooperate with the central portion 182a to define the first articulation surface <NUM>; however, the first articulation surface <NUM> may be substantially uniform or continuous. With reference back to <FIG>, the first articulation surface <NUM> cooperates with the movable needle mount <NUM> to enable the cannula <NUM> to move or pivot relative to an angle α defined between a central vertical axis V of the infusion unit <NUM> and an axis A3 through a center line of the cannula <NUM>. In one example, with reference to <FIG>, the angle α is about <NUM> degrees to about <NUM> degrees. In one example, the movable needle mount <NUM> is movable or pivotable an angle β relative to the angle α. In this example, angle β is about ± <NUM> degrees to about ± <NUM> degrees relative to the angle α. Generally, the center of rotation CR of angle β is approximately at the entry point of the cannula <NUM> into the skin S (<FIG>) within about ± <NUM> millimeters (mm). It should be noted that the movement of the cannula <NUM> is conical, and the movement of the cannula <NUM> about the angle β is a conical movement in and out of the plane shown in <FIG>. As shown in <FIG>, a deflection of the movable needle mount <NUM> has caused the cannula <NUM> to rotate a positive angle β relative to the vertical axis V. In <FIG>, a deflection of the movable needle mount <NUM> has caused the cannula <NUM> to rotate a negative angle β relative to the vertical axis V.

With reference to <FIG>, the plurality of coupling slots <NUM> are spaced apart about the perimeter or outer circumference of the inner housing <NUM>. In one example, the inner housing <NUM> includes about <NUM> coupling slots <NUM>, which cooperate with the mount <NUM> to secure the inner housing <NUM> to the mount <NUM>. In this example, each of the coupling slots <NUM> is sized to receive a portion of the mount <NUM> to retain the inner housing <NUM> on the mount <NUM>. With reference back to <FIG>, the clearance aperture <NUM> is defined through the outer surface <NUM> and the inner surface <NUM> at a first end 132a of the inner housing <NUM>. In one example, the clearance aperture <NUM> extends from the perimeter or outer circumference of the inner housing <NUM> to a point P proximate the central axis A2 of the inner housing <NUM>. The clearance aperture <NUM> provides space or a volume for the movable needle mount <NUM> and/or tube <NUM> to move relative to the inner housing <NUM>. The needle bore <NUM> is defined through the outer surface <NUM> and the inner surface <NUM>. The needle bore <NUM> is generally defined through the inner housing <NUM> so as to extend through a portion of the first articulation surface <NUM>. Thus, in this example, the needle bore <NUM> is offset from the central axis A2 of the inner housing <NUM>, and is near the second end 132b of the inner housing <NUM>. In one example, the needle bore <NUM> extends along an axis that is transverse or oblique to the central axis A2 of the inner housing <NUM>. The needle bore <NUM> receives a portion of the needle hub <NUM> (<FIG>) to install the infusion unit <NUM> on the user.

With reference to <FIG>, the biasing member <NUM> returns the movable needle mount <NUM> to a first, initial or neutral position (<FIG>). In the neutral position, the movable needle mount <NUM> is at the angle α relative to the vertical axis V. A movement or pivoting of the movable needle mount <NUM> compresses the biasing member <NUM> to provide a spring force to return the movable needle mount <NUM> to the neutral position. In this example, with reference to <FIG>, the biasing member <NUM> is a disc spring, which is substantially annular. The biasing member <NUM> is composed of an elastomeric material, including, but not limited to, a silicone or thermoplastic elastomer (TPE). The biasing member <NUM> is molded; however, the biasing member <NUM> may be formed through any suitable technique. The biasing member <NUM> includes a central member bore <NUM>, a member clearance bore <NUM> and a plurality of member slots <NUM>. In one example, the biasing member <NUM> includes a member hub <NUM> integrally formed with a member flange <NUM>. In this example, a portion of the perimeter or outer circumference of the inner housing <NUM> contacts the member flange <NUM> when the inner housing <NUM> is coupled to the mount <NUM>, and the movable needle mount <NUM> contacts a portion of the member hub <NUM>, as shown in <FIG>. The member hub <NUM> is substantially convex, and in one example, the member hub <NUM> includes a relief 192a that extends about an inner perimeter of the member hub <NUM>. In this example, a portion of the movable needle mount <NUM> is received within the relief 192a. With reference back to <FIG>, the central member bore <NUM> is defined through the member hub <NUM> and extends along an axis A4, which is substantially parallel to the vertical axis V. The central member bore <NUM> is sized to receive and cooperate with the movable needle mount <NUM>.

The member clearance bore <NUM> is defined through the member hub <NUM> and the member flange <NUM>. The member clearance bore <NUM> provides room or space for the tube <NUM> to be received within the movable needle mount <NUM>, and for the movable needle mount <NUM> and/or the tube <NUM> to move or pivot. The member clearance bore <NUM> is defined so as to be aligned with the clearance bore of the inner housing <NUM>. The plurality of member slots <NUM> are defined through the member flange <NUM> substantially about the perimeter or outer circumference of the biasing member <NUM>. Generally, the biasing member <NUM> includes about <NUM> member slots <NUM>, which are each aligned with a respective one of the coupling slots <NUM> to enable the inner housing <NUM> to be coupled to the mount <NUM> (<FIG>). In this example, each of the member slots <NUM> is sized to enable a portion of the mount <NUM> pass therethrough (<FIG>).

The movable needle mount <NUM> enables the cannula <NUM> to move or pivot relative to the inner housing <NUM>, and thus, the infusion unit <NUM>. In one example, the movable needle mount <NUM> enables the cannula <NUM> to move or pivot when the skin S (<FIG>) of the user moves or when an external force or load is applied to the infusion unit <NUM>. In one example, the movable needle mount <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The movable needle mount <NUM> may be formed through molding, casting, printing, etc. With reference to <FIG>, the movable needle mount <NUM> includes a tube receiving portion <NUM>, a needle guide <NUM>, a septum <NUM>, a septum bore <NUM> and a second articulation surface <NUM>. In one example, the movable needle mount <NUM> is substantially conical, but the movable needle mount <NUM> may have any desired shape.

The tube receiving portion <NUM> is substantially cylindrical, and is sized to receive the first end <NUM> of the tube <NUM> and to cooperate with the tube <NUM> to define the fluid flow path to the user. The tube receiving portion <NUM> is defined at a first end 136a of the movable needle mount <NUM>. The tube receiving portion <NUM> includes a first end <NUM> and an opposite second end <NUM>. The first end <NUM> receives a portion of the tube <NUM> adjacent to the first end <NUM>. The second end <NUM> is fixedly coupled to the first end <NUM> of the tube <NUM>, and includes an outlet <NUM>. Generally, the first end <NUM> of the tube <NUM> is fixedly coupled to the second end <NUM> via any suitable technique, including, but not limited to, adhesives, ultrasonic welding, etc. The outlet <NUM> defines a fluid flow path from the first end <NUM> of the tube <NUM> to the cannula <NUM>. The outlet <NUM> is in fluid communication with the needle guide <NUM> to direct the fluid from the fluid reservoir of the fluid infusion device <NUM> into the body of the user.

The needle guide <NUM> includes an inlet <NUM>, a needle coupling bore <NUM> and an annular guide <NUM>. The inlet <NUM> is in fluid communication with the outlet <NUM> to receive the fluid. In one example, the inlet <NUM> is funnel shaped to direct the fluid from the outlet <NUM> into the cannula <NUM>. The needle coupling bore <NUM> is defined between the inlet <NUM> and the annular guide <NUM>. The cannula <NUM> is fixedly coupled to the needle coupling bore <NUM>. In one example, the cannula <NUM> is fixedly coupled to the needle coupling bore <NUM> via adhesives, ultrasonic welding, molding, etc. The annular guide <NUM> extends outwardly about the needle coupling bore <NUM> toward the mount <NUM>. The annular guide <NUM> surrounds the cannula <NUM>, and provides a stop for a movement or rotation of the cannula <NUM>. In this regard, the annular guide <NUM> includes a flat surface <NUM> that extends about a periphery of the annular guide <NUM>. A portion of the flat surface <NUM> contacts a portion of the mount <NUM> to limit a range of motion of the cannula <NUM>.

The septum <NUM> is coupled to the septum bore <NUM>. In one example, the septum <NUM> is fixedly coupled to the septum bore <NUM> via adhesives, ultrasonic welding, press-fit, etc. The septum <NUM> is generally circular; however, the septum <NUM> may have any desired shape. The septum <NUM> serves as a barrier to prevent the ingress and egress of fluids into the fluid flow path defined by the tube <NUM> and the cannula <NUM> within the infusion unit <NUM>. The septum <NUM> is pierceable by an introducer pin <NUM> of the needle hub <NUM> to enable the user to install the infusion unit <NUM>. The septum bore <NUM> is defined through the second articulation surface <NUM> and is in communication with the inlet <NUM>. The septum bore <NUM> is sized and shaped to receive the septum <NUM>, and thus, in this example is substantially cylindrical.

The second articulation surface <NUM> is spherical and convex. The second articulation surface <NUM> is defined on an outer surface <NUM> of the movable needle mount <NUM> so as to be offset from the central axis A2 of the inner housing <NUM> and the vertical axis V that extends through the infusion unit <NUM>. In this example, the movable needle mount <NUM> is offset from the vertical axis V toward a second end 136b of the movable needle mount <NUM>. Generally, with reference to <FIG>, the second articulation surface <NUM> extends from a first side 136c of the outer surface <NUM> of the movable needle mount <NUM> to a second, opposite side 136d of the outer surface <NUM> of the movable needle mount <NUM> near or adjacent to the second end 136b of the movable needle mount <NUM>. Generally, the second articulation surface <NUM> cooperates with the first articulation surface <NUM> to enable the cannula <NUM> to move or pivot positive or negative the angle β relative to the angle α. Generally, with reference to <FIG>, the first articulation surface <NUM> and the second articulation surface <NUM> are defined on the infusion unit <NUM> such that the center of rotation CR of the cannula <NUM> is located near the entry point of the cannula <NUM> into the skin S of the user (<FIG>). The rotation of the cannula <NUM> about the vertical axis V of the infusion unit <NUM> is symmetric and conical, however, it should be understood that the angle of rotation of the cannula <NUM> may be asymmetrical, if desired.

In this example, with reference to <FIG>, the movable needle mount <NUM> also includes a ledge <NUM>. The ledge <NUM> is defined about a perimeter of the movable needle mount <NUM>, and is sized to be received within the relief 192a of the member hub <NUM>. In this example, the ledge <NUM> contacts and rests on the relief 192a of the member hub <NUM> so that the biasing member <NUM> may apply the spring force to the movable needle mount <NUM> to return the movable needle mount <NUM> to the neutral position.

With reference to <FIG>, the mount <NUM> is coupled to the coupling device <NUM> and to the inner housing <NUM>. The mount <NUM> is substantially circular; however, the mount <NUM> may have any desired shape. In one example, the mount <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The mount <NUM> may be formed through molding, casting, printing, etc. The mount <NUM> includes a first mount surface <NUM>, a second mount surface <NUM> opposite the first mount surface <NUM> and a central mount bore <NUM>. The first mount surface <NUM> includes a plurality of projections <NUM>, a plurality of snap fingers <NUM> and a needle mount interface <NUM>.

The plurality of projections <NUM> extend axially upward from a perimeter or outer circumference of the first mount surface <NUM> of the mount <NUM>. In one example, the mount <NUM> includes <NUM> projections <NUM>; however, the mount <NUM> may have any number of projections <NUM>. Each of the plurality of projections <NUM> are spaced apart about the perimeter of the mount <NUM> from a first projection 240a to a last projection <NUM>. A clearance <NUM> is defined between the first projection 240a and the last projection <NUM> to enable the tube <NUM> to be received within the infusion unit <NUM>. Stated another way, the projections <NUM> are spaced about the perimeter of the mount <NUM> between the first projection 240a and the last projection <NUM> to define the clearance <NUM>. With reference to <FIG>, each of the projections <NUM> includes a first end <NUM> and an opposite second end <NUM>. The first end <NUM> is integrally formed with the mount <NUM>, and the second end <NUM> is a free end. The second end <NUM> may include a curvature or taper 250a that corresponds with the outer surface <NUM> of the inner housing <NUM> to provide an aesthetically pleasing appearance. An inner surface <NUM> of each of the projections <NUM> contacts the biasing member <NUM> and the inner housing <NUM> to assist in retaining the biasing member <NUM> and the inner housing <NUM> on the mount <NUM>.

With reference to <FIG>, the plurality of snap fingers <NUM> are defined so as to be cantilevered relative to the mount <NUM> to enable the snap fingers <NUM> to move or flex to couple the inner housing <NUM> to the mount <NUM>. In one example, a slot <NUM> is defined on respective sides of each of the snap fingers <NUM> to enable the respective snap finger <NUM> to move relative to the mount <NUM>. Each of the snap fingers <NUM> extend axially upward from the perimeter or outer circumference of the first mount surface <NUM> of the mount <NUM>. Each of the snap fingers <NUM> includes a first end <NUM> and an opposite second end <NUM>. The first end <NUM> is integrally formed with the mount <NUM>, and the second end <NUM> includes a hook <NUM>. With reference to <FIG>, the hook <NUM> cooperates with the outer surface <NUM> of the inner housing <NUM> to couple the inner housing <NUM>, the biasing member <NUM> and the movable needle mount <NUM> to the mount <NUM>. Thus, generally, the inner housing <NUM>, the biasing member <NUM> and the movable needle mount <NUM> are snap fit to the mount <NUM>. In this example, the mount <NUM> includes about <NUM> snap fingers <NUM>; however, the mount <NUM> may include any number of snap fingers. Furthermore, in certain embodiments, the mount <NUM> need not include the snap fingers <NUM>, as the mount <NUM> may be coupled to the inner housing <NUM> via an adhesive, ultrasonic welding, etc..

The needle mount interface <NUM> cooperates with the movable needle mount <NUM> to limit an amount of movement or rotation of the movable needle mount <NUM>. In one example, with reference to <FIG>, the needle mount interface <NUM> includes a first ramp surface <NUM> and a contoured surface <NUM>. The first ramp surface <NUM> provides a stop or contact surface for the tube receiving portion <NUM> of the movable needle mount <NUM>, which limits a movement or rotation of the movable needle mount <NUM>. In one example, the first ramp surface <NUM> has an incline that is shaped to cooperate with an outer surface of the tube receiving portion <NUM>. It should be noted, however, that the first ramp surface <NUM> may have any desired shape to provide a stop for a movement of the tube receiving portion <NUM>. The contoured surface <NUM> has a shape that is configured to match an exterior surface of the inlet <NUM> and the annular guide <NUM> of the movable needle mount <NUM>. In one example, the contoured surface <NUM> includes an inclined surface 262a, a flat surface 262b and a rib 262c. Each of the inclined surface 262a, the flat surface 262b and the rib 262c cooperate to limit a further advancement or movement of the cannula <NUM>, for example, when the inner housing <NUM> is compressed by an external force. In the example of a compression of the inner housing <NUM> by the external force, an exterior surface of the annular guide <NUM> contacts the inclined surface 262a and an exterior surface of the inlet <NUM> contacts the flat surface 262b and the rib 262c.

The first mount surface <NUM> may also include a concave relief 230a. The concave relief 230a may receive a portion of the tube <NUM> during a movement or pivoting of the movable needle mount <NUM>. The second mount surface <NUM> is substantially flat or planar. The second mount surface <NUM> is coupled to the coupling device <NUM>. With reference to <FIG>, the central mount bore <NUM> is defined through the first mount surface <NUM> and the second mount surface <NUM>. In one example, the central mount bore <NUM> is defined through the needle mount interface <NUM> of the first mount surface <NUM>. The cannula <NUM> and a portion of the annular guide <NUM> extend through the central mount bore <NUM>.

With reference to <FIG>, the coupling device <NUM> removably couples or secures the mount <NUM> of the infusion unit <NUM> to the body of the user. In one example, the coupling device <NUM> includes a mounting layer <NUM>, an adhesive layer <NUM> and a backing <NUM>. It should be noted that the mounting layer <NUM> and the adhesive layer <NUM> are illustrated herein as having a nominal thickness, but that the mounting layer <NUM> and the adhesive layer <NUM> could have any suitable thickness as necessary for the manufacture of the coupling device <NUM>. The mounting layer <NUM> and adhesive layer <NUM> may be separately or integrally formed. The mounting layer <NUM> couples or fixedly attaches the adhesive layer <NUM> to the second mount surface <NUM> of the mount <NUM>. The mounting layer <NUM> may be coupled or secured to the second mount surface <NUM> of the mount <NUM> through any suitable technique, including, but not limited to, ultrasonic welding. Generally, the mounting layer <NUM> is coupled to substantially the entirety of the second mount surface <NUM> of the mount <NUM> and a surface 162b associated with each base <NUM> of the retaining flanges <NUM> of the outer housing <NUM>. Thus, in one example, the mounting layer <NUM> is fixedly coupled to the mount <NUM> and to the outer housing <NUM>. It should be noted, however, that while the mounting layer <NUM> is illustrated herein as being defined over substantially an entire surface of the coupling device <NUM>, the mounting layer <NUM> may be coupled to just a portion of the surface of the adhesive layer <NUM>. For example, the mounting layer <NUM> may be coupled to the adhesive layer <NUM> so as to extend over a portion of the adhesive layer <NUM> that corresponds with the portion of the coupling device <NUM> that is coupled to the mount <NUM> and/or the outer housing <NUM>. In other words, the mounting layer <NUM> may be sized to correspond to the size of the mount <NUM> and/or outer housing <NUM>, and can have a shape that may be different than a shape of the adhesive layer <NUM>.

The adhesive layer <NUM> enables the infusion unit <NUM> to be removably coupled to the body of the user. It should be noted that the use of the adhesive layer <NUM> is merely exemplary, as any suitable technique could be used to removably couple the infusion unit <NUM> to the user. In one example, with reference to <FIG>, the adhesive layer <NUM> is shown in greater detail. In this example, the adhesive layer <NUM> defines a plurality of projections or pedals <NUM>, which extend radially outward from a central portion <NUM> of the adhesive layer <NUM>. Generally, the adhesive layer <NUM> includes a pedal <NUM> for each one of the retaining flanges <NUM> of the outer housing <NUM>. Thus, in this example, the adhesive layer <NUM> includes <NUM> pedals <NUM>; however, the adhesive layer <NUM> may include any number of pedals.

In the example of the mounting layer <NUM> being shaped to correspond to the adhesive layer <NUM>, with reference back to <FIG>, the mounting layer <NUM> also includes a plurality of pedals 270a. Each of the pedals 270a of the mounting layer <NUM> are coupled to the surface 162b of a respective one of the bases <NUM>, while a central portion 270b of the mounting layer <NUM> is coupled to the mount <NUM>. Similarly, each of the pedals <NUM> of the adhesive layer <NUM> may be coupled to the skin S (<FIG>) of the user and the central portion <NUM> of the adhesive layer <NUM> may be coupled to the skin S of the user. By providing the mounting layer <NUM> and the adhesive layer <NUM> with the pedals 270a, <NUM>, less strain is applied to the skin S (<FIG>) of the user. The central portion 270b of the mounting layer <NUM> includes a bore 270c, which is sized to enable a portion of the cannula <NUM> to pass therethrough. With reference back to <FIG>, the central portion <NUM> of the adhesive layer <NUM> also includes a bore 278a, which is also sized to enable a portion of the cannula <NUM> to pass therethrough. The backing <NUM> is coupled to at least a portion of the adhesive layer <NUM>, and is removable to facilitate coupling the coupling device <NUM> to the user, as is generally known. It should be noted that while the mounting layer <NUM> and the adhesive layer <NUM> are illustrated and described herein as including the pedals 270a, <NUM>, respectively, the mounting layer <NUM> and/or the adhesive layer <NUM> need not include the pedals 270a, <NUM>. Rather, one or both of the mounting layer <NUM> and the adhesive layer <NUM> may be circular, such as that shown in <FIG>.

With reference back to <FIG>, the cannula <NUM> delivers the fluid from the tube <NUM> into the body of the user. In this example, the cannula <NUM> is composed of a biocompatible metal or metal alloy, including, but not limited to, titanium, nickel-titanium alloy, titanium alloy, stainless steel, etc. It should be noted that the use of a cannula <NUM> composed of titanium, nickel-titanium alloy or titanium alloy results in the cannula <NUM> having increased flexibility when compared to a cannula <NUM> composed of a stainless steel. Thus, the use of titanium, nickel-titanium alloy or titanium alloy for the cannula <NUM> may provide the user with improved comfort. In one example, the cannula <NUM> has an outside diameter that is about or less than <NUM> gauge, and in one example, the cannula <NUM> comprises, but is not limited to, a <NUM> gauge cannula, a <NUM> gauge thin wall (29TW) cannula, a <NUM> gauge extra thin wall (29XTW), a <NUM> gauge, a <NUM> gauge thin wall (30TW) or a <NUM> gauge extra thin wall (30XTW). By reducing the thickness of the wall of the cannula <NUM> through the use of the thin wall or extra thin wall cannulas <NUM>, an outside diameter of the introducer pin <NUM> may be increased relative to the outside diameter of the cannula <NUM>, which results in less insertion strain when the cannula <NUM> follows the introducer pin <NUM> into the skin of the user. The use of the thin wall or extra thin wall cannulas <NUM> provides for a larger inner diameter for the cannula <NUM>, which may reduce occlusions. The cannula <NUM> includes a first cannula end <NUM> and an opposite second cannula end <NUM>. The cannula <NUM> includes a central needle bore <NUM>, which extends from the first cannula end <NUM> to the second cannula end <NUM>. The central needle bore <NUM> enables a portion of the needle hub <NUM> and the fluid from the tube <NUM> to pass therethrough.

With reference to <FIG>, in one example, the first cannula end <NUM> includes a flared portion 280a. The flared portion 280a is shaped to correspond with the funnel shape of the inlet <NUM>. The flared portion 280a and the funnel shape of the inlet <NUM> cooperate to direct the introducer pin <NUM> into the cannula <NUM>. It should be noted that the flared portion 280a of the cannula <NUM> may be optional, and the cannula <NUM> may include a cylindrical or un-flared end, if desired.

With reference to <FIG>, the second cannula end <NUM> is shown in greater detail. In one example, the second cannula end <NUM> has a blunt tip 282a and includes a slot <NUM>. By providing the second cannula end <NUM> with the blunt tip 282a, the cannula <NUM> does not pierce the internal tissue beneath the skin (<FIG>) when the infusion unit <NUM> is compressed against the skin S post insertion, and does not pierce the internal tissue beneath the skin S when the cannula <NUM> rotates. Thus, the use of the blunt tip 282a may reduce site inflammation and discomfort relative to a cannula with a sharp tip. In one example, the blunt tip 282a has a chamfer to minimize discomfort when the cannula <NUM> follows the introducer pin <NUM> into the skin of the user during insertion of the cannula <NUM>. The slot <NUM> extends from the blunt tip 282a for a slot length SL of the cannula <NUM>. In one example, the slot length SL is about <NUM> millimeters (mm) to about <NUM> millimeters (mm). The slot <NUM> has a slot width Sw, which is about <NUM> millimeters (mm) to about <NUM> millimeters (mm). The slot <NUM> may reduce a potential for occlusions at the second cannula end <NUM> caused by a compressive force applied to the blunt tip 282a. The slot <NUM> may be formed in the cannula <NUM> by laser-cutting, however, other machining techniques may be employed. It should be noted that while the second cannula end <NUM> is shown and described herein as including the slot <NUM>, the cannula <NUM> need not include the slot <NUM>, if desired.

With reference back to <FIG>, the needle hub <NUM> is used by a user to install the cannula <NUM> into to the body of the user. In one example, the needle hub <NUM> includes a hub body <NUM> and a removable introducer pin <NUM>. The hub body <NUM> is composed of a polymer-based material, including, but not limited to polypropylene, polycarbonate, polyester, acrylonitrile butadiene styrene (ABS), acetal and blends of these polymer-based materials. In this example, with reference to <FIG>, the hub body <NUM> includes a hub base <NUM> and a graspable portion or handle <NUM>. It should be noted that although not shown herein, the handle <NUM> may be modified to integrate with an insertion aid device, including, but not limited to, a MiniMed Sil-serter®, MiniMed Quick-serter® each commercially available from Medtronic Minimed, Inc. of Northridge, California or the like, to assist the user in inserting the cannula <NUM> at an angle into the skin. The hub base <NUM> has a first hub side <NUM> and a second hub side <NUM>. The first hub side <NUM> includes a recessed midsection <NUM> and a convex flange <NUM>. It should be noted, however, that the first hub side <NUM> may have any desired shape. The recessed midsection <NUM> cooperates with the second hub side <NUM> to contact a portion of the infusion unit <NUM> when the needle hub <NUM> is coupled to the infusion unit <NUM>. The convex flange <NUM> extends about a perimeter of the recessed midsection <NUM>, and is intersected by the handle <NUM>. The convex flange <NUM> surrounds a perimeter of the outer housing <NUM> when coupled to the infusion unit <NUM> and assists in distributing a force applied by the user to ensure that an entirety of the adhesive layer <NUM> is coupled to the skin S of the user.

With reference to <FIG>, the second hub side <NUM> of the hub base <NUM> is shown. The second hub side <NUM> includes a first concave portion <NUM> and a second concave portion <NUM>. The first concave portion <NUM> is opposite the convex flange <NUM>. The first concave portion <NUM> is coupled to and contacts the outer housing <NUM> when the needle hub <NUM> is coupled to the infusion unit <NUM>. The second concave portion <NUM> is opposite the recessed midsection <NUM>. The second concave portion <NUM> is coupled to and contacts the inner housing <NUM> when the needle hub <NUM> is coupled to the infusion unit <NUM>.

The handle <NUM> is integrally formed with the hub body <NUM>. The handle <NUM> enables the user to manipulate the needle hub <NUM> for coupling the infusion unit <NUM> to the skin S (<FIG>) of the user. The handle <NUM> extends outwardly from the first base side <NUM>. In one example, the handle <NUM> includes a cutout <NUM>, a leg <NUM> and an introducer bore <NUM>. The cutout <NUM> transitions the handle <NUM> from the recessed midsection <NUM> to the leg <NUM>, and defines a ledge 310a. The ledge 310a is coupled to and in contact with the hub <NUM> of the outer housing <NUM> when the needle hub <NUM> is coupled to the infusion unit <NUM>. The leg <NUM> includes a surface 312a, which contacts one of the bases <NUM> of one of the retaining flanges <NUM> to assist in coupling the infusion unit <NUM> to the user. The introducer bore <NUM> extends through the handle <NUM> from a first handle end 296a to a second handle end 296b. The introducer bore <NUM> enables the introducer pin <NUM> to be removably received within the handle <NUM>. When the hub base <NUM> is coupled to the infusion unit <NUM>, the introducer bore <NUM> is coaxially aligned with the needle bore <NUM> to enable the introducer pin <NUM> to pass through the needle bore <NUM> and the cannula <NUM> to insert the cannula <NUM> into the anatomy. The introducer bore <NUM> may have varying diameters along the introducer bore <NUM> from the first handle end 296a to the second handle end 296b that correspond to the diameter of the introducer pin <NUM>. It should be noted, however, that the introducer bore <NUM> may have any desired shape that enables the introducer pin <NUM> to pass therethrough.

The introducer pin <NUM> is used by the user to couple the cannula <NUM> to the body of the user. The introducer pin <NUM> may be composed of a biocompatible metal or metal alloy, and is substantially solid or uncannulated. In one example, the introducer pin <NUM> includes a tip <NUM> and an optional graspable portion <NUM>. The tip <NUM> is pointed or sharp for piercing the skin of the user. In one example, the tip <NUM> of the introducer pin <NUM> comprises, but is not limited to, a conical pointed tip, a beveled pointed tip or a trocar tip. The graspable portion <NUM> may provide a grip surface for the user. While the graspable portion <NUM> is shown as an annular thickened portion of the introducer pin <NUM>, the graspable portion <NUM> may have any desired shape. In this example, the graspable portion <NUM> cooperates with a reduced diameter 314a of the introducer bore <NUM> to inhibit a further advancement of the tip <NUM> within the body of the user. Stated another way, the graspable portion <NUM> cooperates with the introducer bore <NUM> to limit an advancement of the introducer pin <NUM> into the user. It should be noted that other techniques may be employed to limit an amount of advancement of the tip <NUM> of the introducer pin <NUM> into the user. In addition, it should be noted that the introducer pin <NUM> may be formed with the needle hub <NUM>, via molding, for example, and in this embodiment, the introducer pin <NUM> may not include the graspable portion <NUM>. In certain embodiments, with reference to <FIG>, the needle hub <NUM>, the introducer pin <NUM>, the infusion unit <NUM>, the connector assembly <NUM> and the tube <NUM> are a kit <NUM>, for fluidly coupling the fluid infusion device <NUM> (<FIG>) to the user.

In order to assemble the infusion unit <NUM> and couple the tube <NUM> to the infusion unit <NUM>, in one example, with the mount <NUM> and biasing member <NUM> formed, the biasing member <NUM> is positioned within the mount <NUM> and is retained by the projections <NUM> substantially about a perimeter of the biasing member <NUM>. With the movable needle mount <NUM> formed, the first end <NUM> of the tube <NUM> is fixedly coupled to the tube receiving portion <NUM> of the movable needle mount <NUM> (<FIG>). Generally, prior to fixedly coupling the tube <NUM> to the movable needle mount <NUM>, the connector assembly <NUM> is coupled to the second end <NUM> of the tube <NUM>. The movable needle mount <NUM> with the tube <NUM> attached is positioned onto the biasing member <NUM> such that the ledge <NUM> contacts the relief 192a of the biasing member <NUM>. With the inner housing <NUM> formed, the inner housing <NUM> is snapped into the mount <NUM> such that the movable needle mount <NUM> and the biasing member <NUM> are sandwiched between the mount <NUM> and the inner housing <NUM> and a portion of the tube <NUM> extends through the clearance aperture <NUM>. In this regard, with reference to <FIG>, generally, each of the projections <NUM> are received in a respective one of the coupling slots <NUM> of the inner housing <NUM>, and the hook <NUM> of each of the snap fingers <NUM> is engaged with the outer surface <NUM> of the inner housing <NUM>. With reference back to <FIG>, with the outer housing <NUM> formed, the outer housing <NUM> is positioned about the inner housing <NUM> and a portion of the tube <NUM> is received within the retaining recess <NUM> such that the portion of the tube <NUM> extends substantially about a circumference of the outer housing <NUM> near the perimeter of the outer housing <NUM>. With the coupling device <NUM> formed, the mounting layer <NUM> is fixedly coupled to the second mount surface <NUM> and the surface 162b of each base <NUM> of the retaining flanges <NUM>. The tube <NUM> may be coupled to the infusion unit <NUM> with the in-line connector 110b and the connector assembly <NUM> coupled to the tube <NUM> such that once the tube <NUM> is coupled to the assembled infusion unit <NUM>, the infusion set <NUM> is formed.

In one example, with the infusion set <NUM> assembled, the hub body <NUM> of the needle hub <NUM> is coupled to the infusion unit <NUM> and the introducer pin <NUM> is coupled to the needle hub <NUM> for packaging and distribution to a user. Once received by a user, the user may remove the pre-assembled infusion set <NUM> out of the packaging. The user connects the infusion set <NUM> to the fluid reservoir of the fluid infusion device <NUM> and the user activates the fluid infusion device <NUM> to prime the infusion set <NUM>. In certain instances, the user may prime a portion of the tube <NUM> coupled to the fluid infusion device <NUM> up to the in-line connector 110b, couple a portion of the tube <NUM> coupled to the infusion unit <NUM> to the remainder of the tube <NUM> at the in-line connector 110b, and once connected, activate the fluid infusion device <NUM> to fill/prime the rest of the tube <NUM> and the infusion unit <NUM>.

The user may clean the insertion site on the skin S of the user with alcohol. With the insertion site prepared, the user may remove the backing <NUM>. With the backing <NUM> removed, the user may manipulate the hub body <NUM>, via the handle <NUM>, to position the infusion unit <NUM> onto the skin S (<FIG>) of the user. In other embodiments, the user may manipulate a quick insertion device to position the infusion unit <NUM> on the skin S of the user. With the infusion unit <NUM> positioned on the skin S of the user, the introducer pin <NUM> is inserted into the introducer bore <NUM> such that the tip <NUM> of the introducer pin <NUM> extends through the cannula <NUM> and pierces the skin S of the user to insert the second cannula end <NUM> of the cannula <NUM> into the body of the user. With the cannula <NUM> inserted into the body of the user, the infusion unit <NUM> is in the installed state. With the infusion unit <NUM> installed, the needle hub <NUM> is uncoupled from the infusion unit <NUM>, which removes the introducer pin <NUM> from the user and leaves the infusion unit <NUM> coupled to or installed on the user. In the installed state, the infusion unit <NUM> provides a fluid flow path from the fluid reservoir associated with the fluid infusion device <NUM> (<FIG>) into the body of the user. The user may smooth out the adhesive layer <NUM>, as needed, once the infusion unit <NUM> is the installed state.

It will be understood that the infusion unit <NUM> of the infusion set <NUM> described with regard to <FIG> may be configured differently to provide a fluid flow path from the fluid infusion device <NUM> to the body of the user. In one example, with reference to <FIG>, an infusion unit <NUM> for the infusion set <NUM> is shown. As the infusion unit <NUM> includes components that are substantially similar to or the same as the infusion unit <NUM> discussed with regard to <FIG>, the same reference numerals will be used to denote the same or similar features.

With reference to <FIG>, the infusion unit <NUM> of the infusion set <NUM> is shown installed onto a skin S of a user. The infusion unit <NUM> delivers fluid from the fluid reservoir associated with the fluid infusion device <NUM> (<FIG>) received via the tube <NUM> into the body of the user. In one example, the infusion unit <NUM> includes a first or outer housing <NUM>, a second or inner housing <NUM>, a mount <NUM>, a coupling device <NUM> and a needle or metal cannula <NUM>.

The outer housing <NUM> surrounds the inner housing <NUM> and the mount <NUM>. Generally, the outer housing <NUM> circumscribes the inner housing <NUM> and the mount <NUM>, but is not coupled to the inner housing <NUM> or the mount <NUM>. The outer housing <NUM> is uncoupled from or discrete from the inner housing <NUM> and the mount <NUM> to provide strain relief to the first end <NUM> of the tube <NUM>. In this regard, by being disjoined from the inner housing <NUM> and the mount <NUM>, any strain imparted to the tube <NUM> will be dissipated by the outer housing <NUM>, which reduces a likelihood of the first end <NUM> of the tube <NUM> being uncoupled from the inner housing <NUM>. In one example, the outer housing <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The outer housing <NUM> may be formed through molding, casting, printing, etc. The outer housing <NUM> is generally concave, however, the outer housing <NUM> may have any desired shape.

In this example, the outer housing <NUM> includes a slot <NUM>, a central aperture <NUM>, an annular hub <NUM> and a plurality of retaining flanges <NUM>. The slot <NUM> is in communication with the central aperture <NUM>, and is elongated to enable an installation of the infusion unit <NUM>. In one example, the slot <NUM> is configured to mate with a needle hub, similar to the needle hub <NUM>, to assist the user in installing the infusion unit <NUM>. The slot <NUM> is defined through a first hub surface 522a of the hub <NUM>. The central aperture <NUM> is defined through a second hub surface 522b of the hub <NUM> of the outer housing <NUM>. The central aperture <NUM> is sized to surround the inner housing <NUM> and the mount <NUM>. In one example, the central aperture <NUM> includes a tapered wall <NUM>. The tapered wall <NUM> is defined to be proximate a tapered wall <NUM> of the inner housing <NUM>. The incline or taper of the tapered wall <NUM> of the outer housing <NUM> is complementary to the incline or taper of the tapered wall <NUM> of the inner housing <NUM> to enable a transfer of forces, such as compressive forces applied to the outer housing <NUM>, between the outer housing <NUM> and the inner housing <NUM>. In on example, a clearance is defined between the inner housing <NUM> and the outer housing <NUM> such that during normal usage the inner housing <NUM> does not contact the outer housing <NUM>.

The hub <NUM> may be coupled to a needle hub to install the infusion unit <NUM> on a body of a user. In one example, the hub <NUM> surrounds the central aperture <NUM> and is interconnected to each of the plurality of retaining flanges <NUM>. The plurality of retaining flanges <NUM> are spaced apart about a perimeter or circumference of the hub <NUM>. In one example, with reference to <FIG>, each of the plurality of retaining flanges <NUM> is separated by a respective one of a plurality of slots <NUM> defined from an outer periphery or perimeter 502a of the outer housing <NUM> to the hub <NUM>. In one example, the outer housing <NUM> includes <NUM> retaining flanges <NUM>, however, the outer housing <NUM> may include any number of retaining flanges, such as <NUM> to <NUM>. With to <FIG> and <FIG>, each of the retaining flanges <NUM> includes a retaining recess <NUM>. The retaining recess <NUM> is substantially U-shaped, and is defined through each of the retaining flanges <NUM> from a first flange surface <NUM> toward a second flange surface <NUM> (<FIG>). Each of the retaining recesses <NUM> are sized and shaped to receive a portion of the tube <NUM> to secure the tube <NUM> to the outer housing <NUM>. Generally, the retaining recesses <NUM> of the retaining flanges <NUM> cooperate to enable the tube <NUM> to be positioned about a circumference of the outer housing <NUM> near the outer perimeter 502a of the outer housing <NUM> (<FIG>). Each of the retaining flanges <NUM> is substantially the same, except for the retaining flange 524a. The retaining flange 524a includes a cutout <NUM> defined through the first flange surface <NUM> that is in communication with the retaining recess <NUM>. The cutout <NUM> enables a portion of the tube <NUM> to pass through the retaining flange 524a.

As will be discussed, with reference to <FIG>, an articulation member enables the cannula <NUM> to move or pivot relative to the inner housing <NUM>, and thus, the outer housing <NUM> and the infusion unit <NUM>. In one example, the articulation member is received within the inner housing <NUM> enables the cannula <NUM> to move or pivot when the skin S of the user moves or when an external force or load is applied to the infusion unit <NUM>. In one example, the inner housing <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The inner housing <NUM> may be formed through molding, casting, printing, etc. With reference to <FIG>, the inner housing <NUM> is substantially annular, however, the inner housing <NUM> may have any desired shape. In one example, with reference back to <FIG>, the inner housing <NUM> includes a tube receiving portion <NUM>, a needle guide <NUM>, a septum <NUM>, a septum bore <NUM>, a seal <NUM> and an articulation member <NUM>. In one example, the inner housing <NUM> is substantially round, but the inner housing <NUM> may have any desired shape.

The tube receiving portion <NUM> is substantially cylindrical, and is sized to receive the first end <NUM> of the tube <NUM> and to cooperate with the tube <NUM> to define the fluid flow path to the user. The tube receiving portion <NUM> is defined at a first needle mount end 506a of the inner housing <NUM>. The tube receiving portion <NUM> includes a first end <NUM> and an opposite second end <NUM>. The first end <NUM> receives a portion of the tube <NUM> adjacent to the first end <NUM>. The first end <NUM> may have a diameter, which is larger than a diameter of the second end <NUM>. In this example, the first end <NUM> is flared outward toward the first needle mount end 506a of the inner housing <NUM>. The outward flare of the first end <NUM> defines a pocket, which may receive an adhesive or other coupling mechanism for securing the tube <NUM> to the tube receiving portion <NUM>. The second end <NUM> is fixedly couple to the first end <NUM> of the tube <NUM>, and includes an outlet <NUM>. Generally, the first end <NUM> of the tube <NUM> is fixedly coupled to the second end <NUM> via any suitable technique, including, but not limited to, adhesives, ultrasonic welding, etc. The outlet <NUM> defines a fluid flow path from the first end <NUM> of the tube <NUM> to the cannula <NUM>. The outlet <NUM> is in fluid communication with the needle guide <NUM> to direct the fluid from the fluid reservoir of the fluid infusion device <NUM> (<FIG>) into the body of the user.

The needle guide <NUM> includes an inlet <NUM>, an articulation member bore <NUM>, and a seal bore <NUM>. The inlet <NUM> is in fluid communication with the outlet <NUM> to receive the fluid. In one example, the inlet <NUM> is substantially funnel shaped to direct the fluid from the outlet <NUM> into the cannula <NUM>. The articulation member bore <NUM> is adjacent to or proximate the inlet <NUM> and is in communication with the inlet <NUM> and the seal bore <NUM>. The articulation member bore <NUM> is substantially spherical and is sized to receive the articulation member <NUM>. The articulation member bore <NUM> enables the articulation member <NUM> to move within the articulation member bore <NUM> based on a movement of the cannula <NUM>, for example. The seal bore <NUM> surrounds a portion of the articulation member bore <NUM>. The seal bore <NUM> is substantially cylindrical, and is sized to receive the seal <NUM>. Generally, the seal <NUM> is fixedly coupled to the seal bore <NUM>, via adhesives, ultrasonic welding, etc..

The septum <NUM> is coupled to the septum bore <NUM>. In one example, the septum <NUM> is fixedly coupled to the septum bore <NUM> via adhesives, ultrasonic welding, press-fit, etc. With reference to <FIG>, the septum <NUM> is generally spherical; however, the septum <NUM> may have any desired shape. The septum <NUM> serves as a barrier to prevent the ingress and egress of fluids into the fluid flow path defined by the tube <NUM> and the cannula <NUM> within the infusion unit <NUM>. The septum <NUM> is pierceable by the introducer pin <NUM> to enable the user to install the infusion unit <NUM>. With reference back to <FIG>, the septum bore <NUM> is defined through a first needle mount surface 506b and is in communication with the inlet <NUM>. The septum bore <NUM> is sized and shaped to receive the septum <NUM>. In one example, the septum bore <NUM> is substantially cylindrical and the septum <NUM> has a diameter that is greater than a diameter of the septum bore <NUM> to create a seal between the septum <NUM> and the septum bore <NUM>.

The seal <NUM> prevents the egress of the fluid from the inlet <NUM>. In one example, with reference to <FIG>, the seal <NUM> is substantially annular. An outer perimeter 558a of the seal <NUM> is fixedly coupled to the seal bore <NUM>, via adhesives, ultrasonic welding, etc. The seal <NUM> is generally composed of a biocompatible polymer-based material, including, but not limited to, an elastomer, silicone, etc. In one example, the seal <NUM> includes a central seal bore <NUM>. The central seal bore <NUM> is cylindrical, and is sized to surround a portion of the articulation member <NUM>, as shown in <FIG>. The central seal bore <NUM> enables the articulation member <NUM> to move while inhibiting the egress of fluid from the inner housing <NUM>.

The articulation member <NUM> is received between the inner housing <NUM> and the mount <NUM>. The articulation member <NUM> is movable relative to the inner housing <NUM> and the mount <NUM> to enable the cannula <NUM> to move relative to the infusion unit <NUM>. The articulation member <NUM> is offset from a central vertical axis V that is defined through the infusion unit <NUM>. In this example, the cannula <NUM> is fixedly coupled to the articulation member <NUM>. In one example, the cannula <NUM> is fixedly coupled to the articulation member <NUM> via adhesives, ultrasonic welding, overmolding, press-fit, etc. Generally, with reference to <FIG>, a first cannula end <NUM> is coupled to the articulation member <NUM> so as to be coincident with an exterior surface 560a of the articulation member <NUM>. Alternatively, the first cannula end <NUM> may be recessed within the articulation member <NUM>. As a further alternative, the first cannula end <NUM> may be flared, similar to the first cannula end <NUM> of the cannula <NUM> of <FIG>. The articulation member <NUM> is spherical, and is composed of a polymer-based material, including, but not limited to polypropylene, polycarbonate, polyester, acrylonitrile butadiene styrene (ABS), acetal, polyether ether ketone (PEEK). The articulation member <NUM> may be formed by molding, printing, casting, etc. In addition, the articulation member <NUM> may be formed by overmolding the articulation member <NUM> onto the cannula <NUM>.

With reference to <FIG>, the articulation member <NUM> moves or pivots along the cooperating spherical surface of the articulation member bore <NUM>. Generally, the articulation member <NUM> cooperates with the inner housing <NUM> to enable the cannula <NUM> to move or pivot relative to the angle α defined between the vertical axis V of the infusion unit <NUM> and the axis A3 through the center line of the cannula <NUM>. In one example, the angle α is about <NUM> degrees to about <NUM> degrees. In one example, the articulation member <NUM> is movable or pivotable the angle β relative to the angle α. In this example, angle β is about ± <NUM> degrees to about ± <NUM> degrees relative to the angle α. Generally, the articulation member <NUM> is coupled to the infusion unit <NUM> such that a center of rotation CR1 of the cannula <NUM> is located near the entry point of the cannula <NUM> into the skin S of the user within about ± <NUM> millimeters (mm). Generally, in one example, the center of rotation CR1 is above the skin S of the user, but within about ± <NUM> millimeters (mm). It should be noted that the movement of the cannula <NUM> is conical, and thus, the movement of the cannula <NUM> about the angle β is a conical movement in and out of the plane shown in <FIG>. In this example, the rotation of the cannula <NUM> about the vertical axis V of the infusion unit <NUM> is symmetric and conical, however, it should be understood that the angle of rotation of the cannula <NUM> may be asymmetrical, if desired. As shown in <FIG>, a movement of the inner housing <NUM> in a direction DR may cause the cannula <NUM> to rotate a negative angle β relative to the vertical axis V of the infusion unit <NUM>. Similarly, a movement of the inner housing <NUM> in a direction opposite the direction DR may cause the cannula <NUM> to rotate a positive angle β relative to the vertical axis V of the infusion unit <NUM>.

In one example, a bore <NUM> of the mount <NUM> may define a range of motion of the cannula <NUM>. In this example, a sidewall 590a of the bore <NUM> may contact the cannula <NUM> to stop the further movement of the cannula <NUM>, and thus, the articulation member <NUM> relative to the inner housing <NUM> and the mount <NUM>. In one example, the sidewall 590a may include an incline on one side. It should be noted, however, that the sidewall 590a may include the incline about an entirety of the sidewall 590a or that the sidewall 590a may be substantially straight.

The inner housing <NUM> is fixedly coupled to the mount <NUM>. In one example, the inner housing <NUM> includes a plurality of mount coupling features or grooves <NUM>, which extend about a portion of a circumference of the inner housing <NUM>. In this example, with reference to <FIG>, the inner housing <NUM> includes two grooves <NUM>, which are spaced apart to define dispensing channels for dispensing an adhesive to couple the inner housing <NUM> to the mount <NUM>. However, it should be noted that in other embodiments, the grooves <NUM> may be employed to define an ultrasonic weld. Generally, with reference to <FIG>, each of the grooves <NUM> are defined from a second needle mount surface 506c toward the first needle mount surface 506b. The first needle mount surface 506b is opposite the second needle mount surface 506c, and the first needle mount end 506a is opposite a second needle mount end 506d. The first needle mount surface 506b may also include a plurality of substantially triangular reliefs <NUM> spaced apart about a circumference of the inner housing <NUM>. The reliefs <NUM> assist in forming the inner housing <NUM>.

The mount <NUM> is coupled to the coupling device <NUM> and to the inner housing <NUM>. The mount <NUM> is substantially circular; however, the mount <NUM> may have any desired shape. In one example, the mount <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The mount <NUM> may be formed through molding, casting, printing, etc. The mount <NUM> includes a first mount surface <NUM>, a second mount surface <NUM> opposite the first mount surface <NUM> and the bore <NUM>.

With reference to <FIG>, the first mount surface <NUM> includes a plurality of ribs <NUM>, a seal interface <NUM> and a tube receiving interface <NUM>. The plurality of ribs <NUM> extend axially upward from the first mount surface <NUM> near the perimeter or outer circumference 600a of the first mount surface <NUM>. In one example, the mount <NUM> includes two circular ribs <NUM>, which extend about a portion of the first mount surface <NUM> and are each intersected by the tube receiving interface <NUM>. Each of the circular ribs <NUM> are received in a respective one of the grooves <NUM> of the inner housing <NUM> to couple the inner housing <NUM> to the mount <NUM>. In one example, the ribs <NUM> are coupled to the grooves <NUM> via adhesives; however, the ribs <NUM> may be coupled to the grooves <NUM> via ultrasonic welding, snap-fit, etc..

The seal interface <NUM> cooperates with the inner housing <NUM> to retain the seal <NUM>. In one example, the seal interface <NUM> is a surface, which is defined radially inward from the ribs <NUM>. The seal interface <NUM> is also generally defined about the bore <NUM>. In one example, a concave recess 590b is defined about the bore <NUM> proximate the seal interface <NUM> to provide an articulation surface for the articulation member <NUM>. The tube receiving interface <NUM> has a shape that corresponds to an exterior surface of the tube receiving portion <NUM> of the mount <NUM>. In one example, the tube receiving interface <NUM> is substantially curved, and includes a concave relief 608a. The concave relief 608a receives part of the exterior surface of the tube receiving portion <NUM> of the inner housing <NUM> to aid in coupling the inner housing <NUM> to the mount <NUM>.

The second mount surface <NUM> is substantially flat or planar. With reference to <FIG>, the second mount surface <NUM> is coupled to the coupling device <NUM>. The bore <NUM> is defined through the first mount surface <NUM> and the second mount surface <NUM>. The bore <NUM> is defined through the mount <NUM> so as to extend substantially along the axis A3, which is transverse or oblique to the vertical axis V. The cannula <NUM> extends through the bore <NUM>.

With reference to <FIG>, the coupling device <NUM> removably couples or secures the mount <NUM> of the infusion unit <NUM> to the body of the user. In one example, with reference to <FIG>, the coupling device <NUM> includes a mounting layer <NUM>, an adhesive layer <NUM> and the backing <NUM>. It should be noted that the mounting layer <NUM> and the adhesive layer <NUM> are illustrated herein as having a nominal thickness, but that the mounting layer <NUM> and the adhesive layer <NUM> could have any suitable thickness as necessary for the manufacture of the coupling device <NUM>. The mounting layer <NUM> and adhesive layer <NUM> may be separately or integrally formed. The mounting layer <NUM> couples or fixedly attaches the adhesive layer <NUM> to the second mount surface <NUM> of the mount <NUM> and to a surface 524b of each of the retaining flanges <NUM>. The mounting layer <NUM> may be coupled or secured to the second mount surface <NUM> of the mount <NUM> and the surface 524b of the retaining flanges <NUM> through any suitable technique, including, but not limited to, ultrasonic welding. Generally, the mounting layer <NUM> is coupled to substantially the entirety of the second mount surface <NUM> of the mount <NUM> and a surface 524b associated with the retaining flanges <NUM> of the outer housing <NUM>. Thus, in one example, the mounting layer <NUM> is fixedly coupled to the mount <NUM> and to the outer housing <NUM>. It should be noted, however, that while the mounting layer <NUM> is illustrated herein as being defined over substantially an entire surface of the coupling device <NUM>, the mounting layer <NUM> may be coupled to just a portion of the surface of the adhesive layer <NUM>. For example, the mounting layer <NUM> may be coupled to the adhesive layer <NUM> so as to extend over a portion of the adhesive layer <NUM> that corresponds with the portion of the coupling device <NUM> that is coupled to the mount <NUM> and/or the outer housing <NUM>. In other words, the mounting layer <NUM> may be sized to correspond to the size of the mount <NUM> and/or outer housing <NUM>, and can have a shape that may be different than a shape of the adhesive layer <NUM>.

The adhesive layer <NUM> enables the infusion unit <NUM> to be removably coupled to the body of the user. It should be noted that the use of the adhesive layer <NUM> is merely exemplary, as any suitable technique could be used to removably couple the infusion unit <NUM> to the user. In one example, the adhesive layer <NUM> is shown in greater detail. In this example, the adhesive layer <NUM> is annular; however, the adhesive layer <NUM> may include a plurality of pedals, such as the plurality of pedals <NUM>. As the mounting layer <NUM> is shaped to correspond to the adhesive layer <NUM>, in this example, the mounting layer <NUM> is also annular. The mounting layer <NUM> includes a bore 610a, which is sized to enable a portion of the cannula <NUM> to pass therethrough. The adhesive layer <NUM> also includes a bore 612a, which is also sized to enable a portion of the cannula <NUM> to pass therethrough. The backing <NUM> is coupled to at least a portion of the adhesive layer <NUM>, and is removable to facilitate coupling the coupling device <NUM> to the user, as is generally known.

With reference to <FIG>, the cannula <NUM> delivers the fluid from the tube <NUM> into the body of the user. In this example, the cannula <NUM> is composed of a biocompatible metal or metal alloy, including, but not limited to, titanium, nickel-titanium alloy, titanium alloy, stainless steel, etc. It should be noted that the use of a cannula <NUM> composed of titanium, nickel-titanium alloy or titanium alloy results in the cannula <NUM> having increased flexibility when compared to a cannula <NUM> composed of a stainless steel. Thus, the use of titanium, nickel-titanium alloy or titanium alloy for the cannula <NUM> may provide the user with improved comfort. In one example, the cannula <NUM> has an outside diameter that is about or less than <NUM> gauge, and in one example, the cannula <NUM> comprises, but is not limited to, a <NUM> gauge cannula, a <NUM> gauge thin wall (29TW) cannula, a <NUM> gauge extra thin wall (29XTW), a <NUM> gauge, a <NUM> gauge thin wall (30TW) or a <NUM> gauge extra thin wall (30XTW). By reducing the thickness of the wall of the cannula <NUM> through the use of the thin wall or extra thin wall cannulas <NUM>, an outside diameter of the introducer pin <NUM> may be increased relative to the outside diameter of the cannula <NUM>, which results in less insertion strain when the cannula <NUM> follows the introducer pin <NUM> into the skin of the user. The use of the thin wall or extra thin wall cannulas <NUM> allow provides for a larger inner diameter for the cannula <NUM>, which may reduce occlusions. The cannula <NUM> includes the first cannula end <NUM> and the opposite second cannula end <NUM>. The cannula <NUM> includes the central needle bore <NUM>, which extends from the first cannula end <NUM> to the second cannula end <NUM>. In one example, the first cannula end <NUM> is substantially cylindrical.

The introducer pin <NUM> is used to insert the cannula <NUM> into the body of the user. In one example, the tip <NUM> of the introducer pin <NUM> pierces the skin S (<FIG>) of the user to insert the cannula <NUM> into the body of the user. The graspable portion <NUM> may provide a grip surface for the user to manipulate the introducer pin <NUM>. It should be noted that although not shown herein, the graspable portion <NUM> may be modified to integrate with an insertion aid device, including, but not limited to, a MiniMed Sil-serter®, MiniMed Quick-serter® each commercially available from Medtronic Minimed, Inc. of Northridge, California or the like, to assist the user in inserting the cannula <NUM> at an angle into the skin. In certain embodiments, with reference to <FIG>, the introducer pin <NUM>, the infusion unit <NUM>, the connector assembly <NUM> and the tube <NUM> are a kit <NUM>, for fluidly coupling the fluid infusion device <NUM> (<FIG>) to the user.

In order to assemble the infusion unit <NUM>, in one example, with the mount <NUM> and the seal <NUM> formed, the seal <NUM> is positioned within the mount <NUM> on the seal interface <NUM>. With the inner housing <NUM> formed, the first end <NUM> of the tube <NUM> is fixedly coupled to the tube receiving portion <NUM> of the inner housing <NUM> (<FIG>). Generally, prior to fixedly coupling the tube <NUM> to the inner housing <NUM>, the connector assembly <NUM> is coupled to the second end <NUM> of the tube <NUM>. With the articulation member <NUM> and the cannula <NUM> formed, the cannula <NUM> is fixedly coupled to the articulation member <NUM> so as to extend through the articulation member <NUM>. The articulation member <NUM> is coupled to the central seal bore <NUM> of the seal <NUM> such that the cannula <NUM> extends through the bore <NUM> of the mount <NUM>. The septum <NUM> is inserted into the septum bore <NUM> of the inner housing <NUM>, and the inner housing <NUM>, with the tube <NUM> attached, is coupled to the mount <NUM> such that the ribs <NUM> are snap-fit into a respective one of the grooves <NUM> (<FIG>).

With reference to <FIG>, the tube <NUM> may be positioned about the outer perimeter of the inner housing <NUM> and the mount <NUM>. With the outer housing <NUM> formed, the outer housing <NUM> is positioned about the inner housing <NUM> and a portion of the tube <NUM> is received within the retaining recess <NUM> such that the portion of the tube <NUM> extends substantially about a circumference of the outer housing <NUM> near the perimeter 502a of the outer housing <NUM>, as shown in <FIG>. With the coupling device <NUM> formed, the mounting layer <NUM> is fixedly coupled to the second mount surface <NUM> and the surface 524b of each of the retaining flanges <NUM>. The tube <NUM> may be coupled to the infusion unit <NUM> with the in-line connector 110b and the connector assembly <NUM> coupled to the tube <NUM> such that once the tube <NUM> is coupled to the assembled infusion unit <NUM>, the infusion set <NUM> is formed.

In one example, with the infusion set <NUM> assembled, a needle hub is coupled to the infusion unit <NUM> and the introducer pin <NUM> is coupled to the needle hub for packaging and distribution to a user. Once received by a user, the user may remove the pre-assembled infusion set <NUM> out of the packaging. The user connects the infusion set <NUM> to the fluid reservoir of the fluid infusion device <NUM> and the user activates the fluid infusion device <NUM> to prime the infusion set <NUM>. In certain instances, the user may prime a portion of the tube <NUM> coupled to the fluid infusion device <NUM> up to the in-line connector 110b, couple a portion of the tube <NUM> coupled to the infusion unit <NUM> to the remainder of the tube <NUM> at the in-line connector 110b, and once connected, activate the fluid infusion device <NUM> to fill/prime the rest of the tube <NUM> and the infusion unit <NUM>.

The user may clean the insertion site on the skin S of the user with alcohol. With the insertion site prepared, the user may remove the backing <NUM>. With the backing <NUM> removed, the user may manipulate the outer housing <NUM> via the needle hub coupled to the outer housing <NUM>, for example, to position the infusion unit <NUM> onto the skin S (<FIG>) of the user. In other embodiments, the user may manipulate a quick insertion device to position the infusion unit <NUM> on the skin S of the user. With the infusion unit <NUM> positioned on the skin S of the user, the introducer pin <NUM> is inserted into the septum bore <NUM> such that the tip <NUM> of the introducer pin <NUM> extends through the cannula <NUM> and pierces the skin S of the user to insert the second cannula end <NUM> of the cannula <NUM> into the body of the user. With the cannula <NUM> inserted into the body of the user, the infusion unit <NUM> is in the installed state. With the infusion unit <NUM> installed, the needle hub is uncoupled from the infusion unit <NUM>, which uncouples the introducer pin <NUM> from the infusion unit <NUM>, leaving the infusion unit <NUM> coupled to the user. In the installed state, the infusion unit <NUM> provides a fluid flow path from the fluid reservoir associated with the fluid infusion device <NUM> (<FIG>) into the body of the user.

Thus, the infusion unit <NUM>, <NUM> provides for improved comfort for a user by providing a pivoting metal cannula with integral strain relief. In this regard, the use of the metal cannula <NUM>, <NUM> having a blunt second cannula end <NUM> may reduce tissue inflammation as the metal cannula <NUM>, <NUM> does not pierce the tissue when the infusion unit <NUM>, <NUM> is subjected to an external force or load, and does not pierce the tissue when the metal cannula <NUM>, <NUM> moves or pivots. In addition, the use of titanium, nickel-titanium or a titanium alloy for the metal cannula <NUM>, <NUM> imparts flexibility to the metal cannula <NUM>, <NUM> while maintaining a bend and kink resistance of the metal cannula <NUM>, <NUM>, which reduces tissue injury and inflammation and may result in longer wear life. The outer housing <NUM>, <NUM> also distributes external forces and loads, such as compressive loads and shear impacts, over a larger area, which reduces user discomfort. Moreover, by being uncoupled from the movable needle mount <NUM> or the inner housing <NUM>, the respective outer housing <NUM>, <NUM> reduces a potential for the tube <NUM> detaching from the movable needle mount <NUM> or the inner housing <NUM> and improves user comfort as any pulling of the tube <NUM> results in pulling on the respective outer housing <NUM>, <NUM> and not on the respective movable needle mount <NUM> or the inner housing <NUM>. Further, the decoupled outer housing <NUM>, <NUM> reduces a need for another adhesive layer to secure the respective inner housing <NUM> or inner housing <NUM> as any strain imparted to the tube <NUM> is distributed through the respective outer housing <NUM>, <NUM>. The use of the coupling device <NUM> having the adhesive layer <NUM> with the pedals <NUM> also improves user comfort by reducing circumferential strain on curved portions of the user's body. In addition, the pedals <NUM> reduce a potential for the adhesive layer <NUM> to peel off the user's body, as a peeling of one of the pedals <NUM> would likely not result in a peeling off of the central portion <NUM> of the adhesive layer <NUM> since the peeling of one of the pedals <NUM> would likely not propagate through the central portion <NUM>. Thus, the adhesive layer <NUM> of the coupling device <NUM> reduces a likelihood of the infusion unit <NUM> being inadvertently uncoupled from the user.

In addition, it should be noted that while the outer housing <NUM>, <NUM> has been described and illustrated herein as a substantially conical structure that surrounds the inner housing <NUM> and the inner housing <NUM>, respectively, it should be understood that the outer housing <NUM>, <NUM> may be configured in a number of different ways to provide strain relief to the infusion unit <NUM>, <NUM>. In one example, the outer housing may comprise a plurality of individual, separate or segmented "pie" pieces, which are positioned about the respective one of the inner housing <NUM> and the inner housing <NUM>. Each of the segmented pie pieces would be de-coupled from the other segmented pie pieces and from the respective one of the inner housing <NUM> and the inner housing <NUM>, enhancing overall site flexibility and comfort. In other example, instead of the outer housing, a thin adhesive patch spoke-like structure may be formed and used to adhere the tube <NUM> at multiple locations around the periphery of the inner housing <NUM> and the inner housing <NUM>, which would also serve to protect the inner housing <NUM> and the inner housing <NUM> from strain or impacts.

It will be understood that the infusion unit <NUM> of the infusion set <NUM> described with regard to <FIG> may be configured differently to provide a fluid flow path from the fluid infusion device <NUM> to the body of the user. In one example, with reference to <FIG>, a cross-section of another exemplary infusion unit <NUM> for the infusion set <NUM> is shown. As the infusion unit <NUM> includes components that are substantially similar to or the same as the infusion unit <NUM> discussed with regard to <FIG>, the same reference numerals will be used to denote the same or similar features. The infusion unit <NUM> delivers fluid from the fluid reservoir associated with the fluid infusion device <NUM> (<FIG>) received through the tube <NUM> into the body of the user. In one example, the infusion unit <NUM> includes the first or outer housing <NUM>, a second or inner housing <NUM>, the biasing member <NUM>, an articulation member or movable needle mount <NUM>, a mount <NUM>, the coupling device <NUM> and the needle or metal cannula <NUM> (<FIG>). In this example, the biasing member <NUM> and the movable needle mount <NUM> are received within a chamber defined between the inner housing <NUM> and the mount <NUM>. It should be noted that while the infusion unit <NUM> is described herein as including the biasing member <NUM>, the biasing member <NUM> may be optional.

The outer housing <NUM> surrounds the inner housing <NUM> and the mount <NUM>, but is not coupled to the inner housing <NUM> or the mount <NUM>. The inner housing <NUM> retains the biasing member <NUM> and the movable needle mount <NUM> on the mount <NUM>. In one example, the inner housing <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The inner housing <NUM> may be formed through molding, casting, printing, etc. The inner housing <NUM> is generally concave, however, the inner housing <NUM> may have any desired shape. The inner housing <NUM> includes an outer surface <NUM>, an inner surface <NUM>, the plurality of coupling slots <NUM>, a tube receiving portion <NUM> and the needle bore <NUM>.

The outer surface <NUM> is substantially smooth, and is substantially conical. The inner surface <NUM> is opposite the outer surface <NUM>. The inner surface <NUM> includes the biasing member clearance surface <NUM> and the first articulation surface <NUM>. The first articulation surface <NUM> is spherical and concave. The first articulation surface <NUM> is defined on the inner surface <NUM> so as to be offset from a central axis of the inner housing <NUM>. In this example, the first articulation surface <NUM> is offset from the central axis toward a second end 702b of the inner housing <NUM>. Generally, the first articulation surface <NUM> extends from a first side of the inner surface <NUM> to a second, opposite side of the inner surface <NUM> near or adjacent to the second end 702b of the inner housing <NUM>. The first articulation surface <NUM> cooperates with the movable needle mount <NUM> to enable the cannula <NUM> to move or pivot relative to the angle α defined between the central vertical axis V of the infusion unit <NUM> and an axis A3 through a center line of the cannula <NUM>. In one example, the movable needle mount <NUM> is movable or pivotable the angle β relative to the angle α.

The tube receiving portion <NUM> is substantially cylindrical, and is sized to receive the first end <NUM> of the tube <NUM> and to cooperate with the tube <NUM> to define the fluid flow path to the user. The tube receiving portion <NUM> is defined at a first end 702a of the inner housing <NUM>. The tube receiving portion <NUM> includes a first end <NUM> and an opposite second end <NUM>. The first end <NUM> receives a portion of the tube <NUM> adjacent to the first end <NUM>. The second end <NUM> is fixedly coupled to the first end <NUM> of the tube <NUM>, and includes an outlet <NUM>. Generally, the first end <NUM> of the tube <NUM> is fixedly coupled to the second end <NUM> via any suitable technique, including, but not limited to, adhesives, ultrasonic welding, etc. The outlet <NUM> defines a fluid flow path from the first end <NUM> of the tube <NUM> into the movable needle mount <NUM>. The outlet <NUM> is in fluid communication with the movable needle mount <NUM> to direct the fluid from the fluid reservoir of the fluid infusion device <NUM> into the body of the user.

The movable needle mount <NUM> enables the cannula <NUM> to move or pivot relative to the inner housing <NUM>, and thus, the infusion unit <NUM>. In one example, the movable needle mount <NUM> enables the cannula <NUM> to move or pivot when the skin S (<FIG>) of the user moves or when an external force or load is applied to the infusion unit <NUM>. In one example, the movable needle mount <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The movable needle mount <NUM> may be formed through molding, casting, printing, etc. In one example, the movable needle mount <NUM> includes the needle guide <NUM>, the septum <NUM>, the septum bore <NUM>, the second articulation surface <NUM>, the ledge <NUM>, a fluid conduit <NUM> and at least one sealing member <NUM>. In one example, the movable needle mount <NUM> is substantially conical, but the movable needle mount <NUM> may have any desired shape.

The fluid conduit <NUM> fluidly couples the movable needle mount <NUM> to the inner housing <NUM>. In one example, the fluid conduit <NUM> is defined through the movable needle mount <NUM> from a first end 704a of the movable needle mount <NUM> to inlet <NUM> of the needle guide <NUM>. The fluid conduit <NUM> is cylindrical; however, the fluid conduit <NUM> may have any desired shape. The fluid conduit <NUM> includes a conduit inlet 730a at the first end 704a, and a conduit outlet 730b. The conduit inlet 730a is fluidly coupled to the outlet <NUM> of the inner housing <NUM>, and the conduit outlet 730b is fluidly coupled to the inlet <NUM> of the needle guide <NUM> to enable fluid to flow from the first end <NUM> of the tube <NUM> through the inner housing <NUM>, the movable needle mount <NUM> and into the cannula <NUM>.

The at least one sealing member <NUM> substantially surrounds the conduit inlet 730a. In one example, the at least one sealing member <NUM> is a single sealing member; however, multiple sealing members may be employed. In this example, the sealing member <NUM> ensures that the fluid from the tube <NUM> enters the fluid conduit <NUM>. The sealing member <NUM> is substantially annular. The sealing member <NUM> is retained between the inner housing <NUM> and the movable needle mount <NUM>. In one example, the sealing member <NUM> may be fixedly coupled to the inner surface <NUM> of the inner housing <NUM>, via adhesives, ultrasonic welding, etc. In this example, the inner surface <NUM> may define an annular recess 712a, which may at least partially receive the sealing member <NUM> and the sealing member <NUM> may be fixedly coupled to the annular recess 712a. The sealing member <NUM> is generally composed of a biocompatible polymer-based material, including, but not limited to, an elastomer, silicone, etc. In one example, the sealing member <NUM> includes a central member bore <NUM>. The central member bore <NUM> is circular, and is sized to surround the conduit inlet 730a. The sealing member <NUM> enables the movable needle mount <NUM> to move while inhibiting the egress of fluid.

The mount <NUM> is coupled to the coupling device <NUM> and to the inner housing <NUM>. The mount <NUM> is substantially circular; however, the mount <NUM> may have any desired shape. In one example, the mount <NUM> is composed of a polymer-based material, including, but not limited to, polypropylene, silicone or a thermoplastic elastomer. The mount <NUM> may be formed through molding, casting, printing, etc. The mount <NUM> includes a first mount surface <NUM>, the second mount surface <NUM> opposite the first mount surface <NUM> and the central mount bore <NUM>. The first mount surface <NUM> includes the plurality of projections <NUM>, the plurality of snap fingers <NUM> and a needle mount interface <NUM>. It should be noted in that in alternative embodiments, the first mount surface <NUM> may include other features that enable the mount <NUM> to be coupled to the inner housing <NUM>, via ultrasonic welding or adhesives, instead of a snap-fit via the plurality of snap fingers <NUM>, for example.

The needle mount interface <NUM> cooperates with the movable needle mount <NUM> to limit an amount of movement or rotation of the movable needle mount <NUM>. In one example, the needle mount interface <NUM> includes a first concave surface <NUM> and a second concave surface <NUM>. The first concave surface <NUM> provides a stop or contact surface for the movable needle mount <NUM>, which limits a movement or rotation of the movable needle mount <NUM>. In one example, the first concave surface <NUM> has a curvature that is shaped to cooperate with an outer surface of the movable needle mount <NUM>. It should be noted, however, that the first concave surface <NUM> may have any desired shape to provide a stop for a movement of the movable needle mount <NUM>. The second concave surface <NUM> has a shape that is configured to match an exterior surface of the annular guide <NUM> of the movable needle mount <NUM>. The second concave surface <NUM> limits a further advancement or movement of the cannula <NUM>, for example, when the inner housing <NUM> is compressed by an external force. In the example of a compression of the inner housing <NUM> by the external force, an exterior surface of the annular guide <NUM> contacts the second concave surface <NUM>.

As the assembly of the infusion unit <NUM> is substantially the same as the assembly of the infusion unit <NUM> discussed with regard to <FIG>, only the differences between the assembly of the infusion unit <NUM> and the infusion unit <NUM> will be discussed in detail herein. Generally, in order to assemble the infusion unit <NUM> and couple the tube <NUM> to the infusion unit <NUM>, in one example, with the movable needle mount <NUM> formed, the movable needle mount <NUM> is positioned onto the biasing member <NUM>. With the inner housing <NUM> formed, the first end <NUM> of the tube <NUM> is fixedly coupled to the tube receiving portion <NUM> of the inner housing <NUM>. Generally, prior to fixedly coupling the tube <NUM> to the inner housing <NUM>, the connector assembly <NUM> is coupled to the second end <NUM> of the tube <NUM>. With the tube <NUM> attached, the inner housing <NUM> is snapped into the mount <NUM> such that the movable needle mount <NUM> and the biasing member <NUM> are sandwiched between the mount <NUM> and the inner housing <NUM> and a portion of the tube <NUM> extends through the clearance aperture <NUM>. With the outer housing <NUM> formed, the outer housing <NUM> is positioned about the inner housing <NUM> and a portion of the tube <NUM> is received within the retaining recess <NUM> such that the portion of the tube <NUM> extends substantially about a circumference of the outer housing <NUM> near the perimeter of the outer housing <NUM>. With the coupling device <NUM> formed, the mounting layer <NUM> is fixedly coupled to the second mount surface <NUM> and the surface 162b of each base <NUM> of the retaining flanges <NUM>. The tube <NUM> may be coupled to the infusion unit <NUM> with the in-line connector 110b and the connector assembly <NUM> coupled to the tube <NUM> such that once the tube <NUM> is coupled to the assembled infusion unit <NUM>, the infusion set <NUM> is formed.

As the installation of the infusion unit <NUM> on the user is substantially the same as the installation of the infusion unit <NUM> on the user discussed with regard to <FIG>, the installation of the infusion unit <NUM> will not be discussed in detail herein.

It will be understood that the fluid infusion system <NUM> described with regard to <FIG> may be configured differently to provide a fluid flow path from a fluid reservoir to the body of the user. In one example, with reference to <FIG>, a fluid infusion system <NUM> is shown. The fluid infusion system <NUM> includes two main components: a fluid infusion device <NUM> (e.g., an insulin patch pump) and an infusion unit <NUM>, which is disposed within and fluidly coupled to the fluid infusion device <NUM>. Thus, in this example, the fluid infusion device <NUM> and the infusion unit <NUM> are coupled to the body of the user. In this example, the fluid infusion device <NUM> accommodates an internal fluid reservoir <NUM> for the fluid to be delivered to the user. A tube <NUM> represents the fluid flow path that couples the fluid reservoir <NUM> to the infusion unit <NUM>. When installed as depicted in <FIG>, the tube <NUM> extends internally from the fluid reservoir <NUM> to the internal infusion unit <NUM>, which in turn provides a fluid pathway to the body of the user through the cannula <NUM>.

The infusion unit <NUM> delivers fluid from the fluid reservoir <NUM> associated with the fluid infusion device <NUM> received through the tube <NUM> into the body of the user. As the infusion unit <NUM> includes components that are substantially similar to or the same as the infusion unit <NUM> discussed with regard to <FIG>, the same reference numerals will be used to denote the same or similar features. In the example, the infusion unit <NUM> includes the second or inner housing <NUM>, the biasing member <NUM>, the articulation member or movable needle mount <NUM>, the mount <NUM> and the needle or metal cannula <NUM>. It should be noted that while the infusion unit <NUM> is described herein as including the biasing member <NUM>, the biasing member <NUM> may be optional. The infusion unit <NUM> provides a fluid flow path from the fluid reservoir <NUM> to the body of the user via the cannula <NUM>, which is movable relative to the fluid infusion device <NUM>.

Thus, the infusion unit <NUM> associated with the fluid infusion device <NUM> provides for the pivotable metal cannula <NUM>, which has a blunt second cannula end <NUM> may reduce tissue inflammation as the metal cannula <NUM> does not pierce the tissue when the infusion unit <NUM> and/or the fluid infusion device <NUM> is subjected to an external force or load, and does not pierce the tissue when the metal cannula <NUM> moves or pivots. In addition, the use of titanium, nickel-titanium or a titanium alloy for the metal cannula <NUM> imparts flexibility to the metal cannula <NUM> of the infusion unit <NUM> while maintaining a bend and kink resistance of the metal cannula <NUM>, which reduces tissue injury and inflammation and may result in longer wear life.

It will be understood that the fluid infusion system <NUM> described with regard to <FIG> may be configured differently to provide a fluid flow path from a fluid reservoir to the body of the user. In one example, with reference to <FIG>, a fluid infusion system <NUM> is shown. The fluid infusion system <NUM> includes two main components: a fluid infusion device <NUM> (e.g., an insulin patch pump) and an infusion unit <NUM>, which is disposed within and fluidly coupled to the fluid infusion device <NUM>.

Thus, in this example, the fluid infusion device <NUM> and the infusion unit <NUM> are coupled to the body of the user. In this example, the fluid infusion device <NUM> accommodates an internal fluid reservoir <NUM> for the fluid to be delivered to the user. A tube <NUM> represents the fluid flow path that couples the fluid reservoir <NUM> to the infusion unit <NUM>. When installed as depicted in <FIG>, the tube <NUM> extends internally from the fluid reservoir <NUM> to the internal infusion unit <NUM>, which in turn provides a fluid pathway to the body of the user through the cannula <NUM>.

The infusion unit <NUM> delivers fluid from the fluid reservoir <NUM> associated with the fluid infusion device <NUM> received through the tube <NUM> into the body of the user. As the infusion unit <NUM> includes components that are substantially similar to or the same as the infusion unit <NUM> discussed with regard to <FIG>, the same reference numerals will be used to denote the same or similar features. In the example, the infusion unit <NUM> includes the second or inner housing <NUM>, the mount <NUM> and the needle or metal cannula <NUM>. The infusion unit <NUM> provides a fluid flow path from the fluid reservoir <NUM> to the body of the user via the cannula <NUM>, which is movable relative to the fluid infusion device <NUM>.

While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist.

Claim 1:
An infusion set (<NUM>) for removable installation onto the skin of a user and for use with a fluid infusion device (<NUM>) having a fluid reservoir, the infusion set comprising:
a cannula (<NUM>, <NUM>) that provides a fluid flow path;
an inner housing (<NUM>, <NUM>, <NUM>) including an articulation member, coupled to the cannula, the articulation member pivotable relative to the inner housing to move the cannula relative to the inner housing, and the inner housing is coupled to a first end (<NUM>) of a fluid supply line (<NUM>) to provide a fluid to the cannula, a second end of the fluid supply line to be coupled to the fluid reservoir to receive the fluid; and
an outer housing (<NUM>, <NUM>) uncoupled from the inner housing that surrounds the inner housing and receives a portion of the fluid supply line such that any strain imparted to the fluid supply line (<NUM>) will be dissipated by the outer housing.