Patent Description:
The present invention relates generally to components and elements of infusion systems, specifically an infusion set with one or more features including tube set strain relief, infusion pumps having heat exchange abilities, oil impregnated plungers, two-direction pumping abilities, Piezo pump devices, and reservoirs made from expanded tubing.

A large number of people suffering from diabetes use some form of daily insulin therapy to maintain close control of their glucose levels. Currently, there are two principal modes of daily insulin therapy. The first mode includes syringes and insulin pens. These devices are simple to use and are relatively low in cost, but they require a needle stick at each injection, typically three to four times per day. The second mode includes infusion pump therapy, which entails the purchase of an insulin pump that lasts for about three years. The initial cost of the pump can be significant, but from a user perspective, the overwhelming majority of patients who have used pumps prefer to remain with pumps for the rest of their lives. This is because infusion pumps, although more complex than syringes and pens, offer the advantages of continuous infusion of insulin, precision dosing and programmable delivery schedules. This results in closer blood glucose control and an improved feeling of wellness.

An infusion pump is but one part of an assembly of infusion elements, which work together to deliver insulin or other medicament to an infusion site. Some elements are disposable, such as the infusion set or pump set which conveys the insulin from a reservoir within the pump into the skin of the user. An infusion set typically consists of a pump connector, a length of tubing, and a hub or base from which an infusion needle, flexible cannula or catheter extends. The hub or base has an adhesive which retains the base of the set on the skin surface during use, which may be applied to the skin manually or with the aid of a manual or automatic insertion device.

As noted above, infusion sets allow diabetic patients to infuse insulin via an infusion pump. To do so, infusion sets use one or more of an infusion needle, flexible cannula or catheter. For example, a steel infusion needle can be used to infuse insulin under the skin surface, either into the subcutaneous or intradermal skin layers, but may irritate the insertion site if moved. Alternatively, a soft, Teflon-based catheter can be provided with the infusion set to infuse insulin under the skin surface, usually into the subcutaneous skin layer, and is associated with less irritation than a steel cannula. However, soft cannulas or catheters are prone to kink which can delay or interrupt the insulin delivery and reduce therapy.

Most soft cannula or catheter infusion sets are inserted using another commonly associated element of infusion sets, a steel introducer needle that is positioned inside the catheter lumen and which extends beyond the catheter to initiate penetration. At insertion and placement, the introducer needle and catheter are both inserted into the infusion site either concurrently with or subsequent to adhesive placement of the infusion set to the skin surface. The introducer needle is then removed from the catheter after penetration, leaving the catheter in place.

Some infusion sets also provide and use a separate spring-loaded inserter that propels the infusion set and/or the introducer needle and catheter into the tissue at a desired speed and to a desired depth. Many such spring-loaded inserters further provide features to automatically retract or shield the introducer needle. Once in place, an infusion set is typically attached to a medicament supply using still another element, such as a length of tubing, which can be subject to inference and adversely affect the infusion set.

Accordingly, each element of the infusion set needs to operate separately and in combination, in an optimal manner. Otherwise, the performance of the infusion set can be adversely affected through the poor performance of individual elements of the infusion se.

A known apparatus for an infusion set is described in <CIT>.

An object of the present invention is to substantially address the above and other concerns, and provide advanced, improved, and novel components and elements of infusion systems that further provide simplicity in manufacture and improvements in use for both insulin and non-insulin applications.

This object is achieved by the invention defined in claim <NUM>. An advantageous embodiment is set out in dependent claim <NUM>.

The various objects, advantages and novel features of the exemplary embodiments of the present invention will be more readily appreciated from the following detailed description when read in conjunction with the appended drawings, in which:.

Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures.

The exemplary embodiments of the present invention described below provide novel means of delivering insulin via an infusion set with one or more advanced features including tube set strain relief, infusion pumps having heat exchange abilities, oil impregnated plungers, two-direction pumping abilities, Piezo pump devices, and reservoirs made from expanded tubing.

In these and other infusion systems, the use of a strain relief can benefit a user in a number of ways, including the extension of the useful life of an infusion set by reducing or eliminating the micro-motion of the catheter caused by movement or tugging of the line set. Further, by eliminating the influence of line set tugging, such provision of a strain relief can ultimately eliminate tunneling or leakage at the infusion site. Accordingly, an exemplary embodiment of the present invention incorporates a strain relief device into an infusion set, and inserter device, or both. <FIG> are perspective views of an exemplary universal strain relief in accordance with an embodiment of the present invention.

In <FIG>, a universal strain relief <NUM> is shown, including an enlarged illustration of the assembly with a tube <NUM> of a set <NUM>. In the exemplary embodiment shown in <FIG>, the strain relief <NUM> comprises an adhesive layer <NUM> such as pressure sensitive adhesive (PSA) secured to a base <NUM>. The base <NUM> rotatably receives a pin <NUM> of a tube holder <NUM>. As shown in the enlargement of <FIG>, the pin <NUM> is captured within an opening <NUM> of the base <NUM> to allow <NUM> degree rotation of the tube holder <NUM>. The tube holder <NUM> can comprise a circular segment of flexible material with an open portion to allow insertion of the tube. The circular segment can be configured to deflect into an open position upon receiving the tube, and contract to a position to secure the tube once the tube is in position. An adhesive liner can also be provided to cover the adhesive layer <NUM>.

In an exemplary use, a user first removes the adhesive liner from the lower surface to expose the adhesive layer of the bottom of the device <NUM>. The device <NUM> is then secured near an infusion site, infusion pump, or therebetween, using the exposed adhesive layer. This ensures that the device <NUM> is fully contacting and adhesively secured to the skin surface. The user then presses the tube <NUM> of the tube set into the tube holder <NUM> as shown in <FIG>.

The tube holder can further comprise an adhesive tab <NUM> as shown in <FIG> that can be used to hold the tube to the tube holder. In an exemplary use, a user first removes the adhesive liner from the lower surface to expose the adhesive layer of the bottom of the device <NUM>. The device <NUM> is then secured near an infusion site, infusion pump, or therebetween, using the exposed adhesive layer as discussed above. The user then presses the tube <NUM> of the tube set into the tube holder and removes the adhesive liner from the adhesive tab <NUM> which is then placed over the tube and the opening of the tube holder.

The strain relief <NUM> of <FIG> is universal in that it can be used with any set or infusion pump, any tube configuration, and provide <NUM> degree rotation of the tube. The strain relief <NUM> can also be used to hold a strain relief loop in place for any set. In yet other embodiments of the present invention, the strain relief device <NUM> can be integrated into the infusion set. <FIG> are perspective views of another strain relief incorporated with the infusion set in accordance with an exemplary configuration.

In <FIG>, an exemplary integrated, spoke-design strain relief <NUM> is shown, including an enlarged illustration of the assembly with a tube <NUM> of an infusion set <NUM>. In the example shown, the strain relief <NUM> comprises one or more flexible arms <NUM> secured to a set <NUM> in a spoke-design pattern. Each arm <NUM> comprises a slot <NUM> for securing the tubing <NUM>. Specifically, the slot <NUM> can comprise a circular segment of flexible material with an open portion to allow insertion of the tube. The circular segment can be configured to deflect into an open position upon receiving the tube, and contract to a position to secure the tube once the tube is in position. The slot can further comprise an adhesive tab (not shown) that can be used to hold the tube to the slot substantially as described it the embodiment above.

In an exemplary use, a user first places the infusion set <NUM> at an infusion site. The user then forms a loop of tubing and presses portions of the tubing loop into each slot <NUM> of each arm <NUM>. As shown in the enlargement of <FIG>, the tubing <NUM> is snapped into the slots <NUM> of the arms <NUM> which then hold the tube <NUM> while providing strain relief. In this example, no additional elements are required as the strain relief element is incorporated with the infusion set. The ability to combine such elements, either integrated with one another, stored with one another, or installed with one another, can simplify use. For example, an inserter can be configured to place both the infusion set and the strain relief, in a single motion. <FIG> are perspective views of an exemplary universal, inserter-placed strain relief in accordance with an exemplary configuration.

In <FIG>, an exemplary inserter <NUM> is shown having an infusion set placement opening <NUM> and a strain relief placement opening <NUM> within a single housing. The housing of the inserter <NUM> contains therein the infusion set and strain relief elements at a distal end, and a single user push button <NUM> at a proximal end. Both elements can be contained therein and covered with an adhesive layer and layer cover (not shown). One or more push buttons <NUM> can be provided to activate the inserter and simultaneously place the set <NUM> and the strain relief <NUM>, which can be separate elements as shown in <FIG>, or integrally formed in yet other exemplary configurationsas shown in <FIG> described below. In doing so, a single user action can be used to place both the set <NUM> and the strain relief <NUM> at an insertion site, without requiring separate user actions. The infusion set and strain relief can share a common adhesive base (not shown) for installation, or can be provided with separate adhesive bases.

An exemplary strain relief <NUM> is shown in <FIG> including an illustration of the assembly with a tube <NUM> of a set <NUM> in <FIG>. In the exemplary configuration shown in <FIG>, the strain relief <NUM> comprises a patch having a raised feature and one or more flexible openings or detents <NUM> for the tubing <NUM> to snap into. Specifically, the flexible openings or detents <NUM> can comprise a circular opening of flexible material with an open portion to allow insertion of the tube. The circular opening can be configured to deflect into an open position upon receiving the tube, and contract to a position to secure the tube once the tube is in position. The opening can further comprise an adhesive tab (not shown) that can be used to hold the tube to the opening substantially as described it the embodiments above. As shown in <FIG> the tubing <NUM> is snapped into the opening <NUM> to hold the tube while providing strain relief.

In an exemplary use, a user first grips the inserter <NUM> and places the distal end of the inserter against a skin surface. The user can then press the single button <NUM> to automatically place both the infusion set <NUM> at an infusion site, and place the strain relief <NUM> at a position near the infusion set <NUM>. The user then forms a loop of tubing and presses a portion of the tubing loop into the flexible openings or detents <NUM> of the strain relief <NUM>. In this example, no additional elements are required as the strain relief element is packaged with the infusion set within the inserter <NUM>. In other exemplary configurations, the strain relief element can be incorporated with the infusion set. Such an exemplary strain relief element incorporated with an infusion set is shown in <FIG> and <FIG>, which are perspective views of another integrated strain relief in accordance with an exemplary configuration.

In <FIG>, a low-profile infusion set <NUM> is shown as placed with a tube set connection element <NUM> integrated with, but isolated from, the infusion set <NUM>. Specifically, as shown in <FIG>, the infusion set <NUM> and the tube set connection element <NUM> are coupled via a tortuous pathed or zigzag patterned portion of a base <NUM> (with or without adhesive), and a similarly patterned portion of tubing <NUM> between the low-profile infusion set <NUM> and tube set connection element <NUM>. In doing so, a tube set <NUM> can be attached to the tube set connection element <NUM> and placed in fluid communication with the infusion set <NUM>, but wherein the infusion set <NUM> is isolated from movement of the tube set <NUM> by the tortuous pathed or zigzag patterned portion of adhesive base <NUM> and tubing <NUM>.

As noted above, the ability to combine such elements, either integrated with one another, stored with one another, or installed with one another, can simplify use. In these examples or other exemplary embodiments of the present invention, such devices can further benefit from the provision of other exemplary strain relief elements. For example, flexible joints or materials in the tube set connections can be used in place of elements that secure the tube at a position away from the set, or which secure extra portions of tubing to absorb movement. For example, <FIG> is a perspective view of an exemplary concertina-type strain relief in accordance with an emexemplary configuration.

In <FIG>, a flexible joint <NUM> is provided at some point along a tube set connection, at the infusion set, infusion pump or somewhere therebetween. The flexible joint <NUM> can be configured as a concertina (i.e., bellows), constructed of silicone or similar materials, to allow movement between one end and another end. In a configuration, the flexible joint <NUM> can be incorporated into the infusion set itself and can include an adhesive patch <NUM> to be secured at an infusion site.

<FIG> is a cross-sectional view of another exemplary flexible joint that is provided at some point along a tube set connection, at the infusion set, infusion pump or somewhere therebetween. The flexible joint of <FIG> can be configured as a male end configured to be slidably captured within a female end to allow movement between one end and another end while maintaining a seal between each. The flexible joint is configured as a two-part, connectable catheter to allow movement between a male end <NUM> and an opposite female end <NUM>. The female end <NUM> comprises an opening surrounded by detents <NUM>. The detents <NUM> are deflectable by engagement with the male end <NUM>. Specifically, the male end <NUM> can comprise inclines <NUM> and a recess <NUM> to slidably capture the detents <NUM> of the female end <NUM>, and permit a degree of movement while providing a seal between each. The detents <NUM> can be strongly biased toward the recess <NUM> when assembled to provide a fluid-tight seal between ends <NUM> and <NUM>.

As noted above, the infusion pump is another part of the assembly of infusion set elements which work together to deliver insulin or other medicament to an infusion site. In configurations, such devices can benefit from the provision of a medicament pump that is configured to pump in both directions, such as a peristaltic pump or a diaphragm pump. The infusion set and pump can then be configured to use the pump to evacuate the reservoir, ideally a flexible reservoir, pressurize the insulin vial or other medicament supply, and draw fluid in from the insulin vial to the reservoir. <FIG>, and <FIG>, are views of an infusion system incorporating a linear peristaltic pump as another part of an assembly of infusion set elements which work together to deliver insulin or other medicament to an infusion site.

<FIG> are block diagrams of an infusion system incorporating a linear peristaltic pump that can be combined with an infusion set and used to deliver insulin or other medicament to an infusion site, and <FIG> are perspective views of an exemplary use of such an infusion system. A peristaltic pump is a positive displacement pump for pumping fluids using a flexible tube which is periodically compressed and released thereby forcing fluid to be pumped through the tube. As shown in <FIG>, an infusion set can comprise a reservoir <NUM>, vial <NUM> and introducer needle, soft catheter, or in-dwelling cannula <NUM>. The reservoir <NUM>, vial <NUM> and introducer needle, soft catheter, or in-dwelling cannula <NUM> can be connected via a valve <NUM>. A linear peristaltic pump <NUM> can be provided at any convenient position such as, for example, between the reservoir <NUM> and the valve <NUM>.

In <FIG>, the linear peristaltic pump <NUM> can be operated to draw air up into the introducer needle, soft catheter, or in-dwelling cannula <NUM> and into the reservoir <NUM>. When a vial <NUM> is coupled to the valve <NUM> in <FIG>, the valve <NUM> and linear peristaltic pump <NUM> can then be operated to force the air from the reservoir <NUM> into the vial <NUM> to pressurize the vial <NUM>. The valve <NUM> and linear peristaltic pump <NUM> can then be operated to pump medicament from the pressurized vial <NUM> to fill the reservoir <NUM> in <FIG>. The valve <NUM> and linear peristaltic pump <NUM> can then be operated to pump medicament from the reservoir <NUM> to the introducer needle, soft catheter, or in-dwelling cannula <NUM> in <FIG>. <FIG> are perspective views of an exemplary use of such a linear peristaltic pump.

<FIG> illustrates an assembly <NUM> containing therein one or more of the linear peristaltic pump <NUM>, reservoir <NUM>, introducer needle, soft catheter, or in-dwelling cannula <NUM> and valve <NUM>. In <FIG> the linear peristaltic pump <NUM> is used to draw air into the reservoir <NUM>. Once the vial <NUM> is connected as shown in <FIG> the linear peristaltic pump <NUM> is used to pressurize the vial <NUM> then fill the reservoir <NUM> from the now pressurized vial <NUM>. Once the vial <NUM> is removed as shown in <FIG>, the linear peristaltic pump <NUM> is used to pump the content of the reservoir <NUM> to the introducer needle, soft catheter, or in-dwelling cannula <NUM> as shown in <FIG>.

A Piezo device can also be utilized as part of an infusion pump, infusion set, or as a separate component for use with either an infusion pump or infusion set. For example, a Piezo-electric pump can be used to move medicament, and can also be used to vibrate an introducer needle, catheter, or in-dwelling cannula on insertion to prevent tenting of the skin. The vibrations caused by the Piezo device or Piezo-electric pump help the edges of the introducer needle, catheter, or in-dwelling cannula to cut tissue, causing a smoother entry of the introducer needle, catheter, or in-dwelling cannula into the tissue. For example, <FIG> are enlarged perspective views of an infusion system incorporating a Piezo device that can be used to deliver insulin or other medicament to an infusion site in accordance with such an exemplary configuration.

<FIG> illustrates an infusion set <NUM> coupled to a Piezo device <NUM> that can be incorporated with, or serve as an infusion pump, or which can be incorporated with, or serve as an infusion set, or as a separate component for use with either an infusion pump or infusion set. A Piezo device is one that incorporates materials that change shape when a voltage is applied, such that the changing shapes can be used to perform a number of tasks. In this case, the Piezo device <NUM> can be constructed to operate as a very small pump, or to create slight vibrations when controlled to do so. In the exemplary configuration, the Piezo device <NUM> can be constructed to provide a communicable vibration to the infusion set <NUM> and specifically, to the introducer needle, catheter, or in-dwelling cannula <NUM> of the infusion set <NUM>. If a Piezo device <NUM> is utilized as part of an infusion patch pump or other infusion set, the Piezo motion can be used to enhance the puncture characteristics of the introducer needle, catheter, or in-dwelling cannula <NUM> into the surface <NUM> of the skin as shown in <FIG> thereby, for example, reducing tenting of the skin surface as shown <FIG> of a conventional insertion without vibration, which can be beneficial to the shallow placement of an introducer needle, catheter, or in-dwelling cannula. The infusion pump can incorporate such features to aid needle, catheter, or in-dwelling cannula insertion or improve pump characteristics. Still other features that can be incorporated into such an infusion system or pump include a heat exchanger (not shown) to maintain the temperature of the insulin or other contents, or cool the insulin or other components of the pump if the temperature rises above a set point.

In other configuration, actual pump functions can be performed by modifying elements of the infusion system. For example, <FIG> are views of a collapsible cylinder or reservoir that can be used to deliver insulin or other medicament to an infusion site.

<FIG> are cross-sectional views of a collapsible cylinder or reservoir <NUM> that can be used to deliver insulin or other medicament to an infusion site. In the exemplary configurationof <FIG>, an insulin vial, cartridge, reservoir or similar element can be constructed from a portion of tubing, such as a portion of the infusion set tubing or other medical grade tubing, preferably one having a high elongation characteristic (e.g., elongation capability of <NUM>% to <NUM>%). In an example shown in <FIG>, for a dimension X, the tubing can be expanded to a length 6X to create a chamber of length 4X, and when released, the tubing can contract to a length 2X, substantially collapsing the entire chamber therein. To do so, the tube segment can be filed with medicament to force the tube segment <NUM> into an elongated shape as shown in <FIG>. The tube segment can be closed at either end with contoured walls <NUM> and <NUM> to reduce dead space when contracted. The filling can further create a tensile force sufficient to deliver the content when released and the tube segment <NUM> contracts due to its high elongation characteristic as shown in <FIG>. The content can be delivered through a cannula or further tube segment <NUM>. In yet another exemplary configuration, the tube segment can be disposed within a reservoir chamber. For example, <FIG> is a cross-sectional view of another collapsible cylinder or reservoir disposed within a structured chamber that can be used to deliver insulin or other medicament to an infusion site in accordance with an embodiment of the present invention.

<FIG> are enlarged cross-sectional views of a collapsible cylinder or reservoir <NUM> disposed within a structured chamber that can be used to deliver insulin or other medicament to an infusion site. In the exemplary configurationof <FIG>, an insulin vial, cartridge, reservoir or similar element is constructed from a portion of tubing <NUM>, such as a portion of the tube set tubing or other medical grade tubing, preferably one having high expansion characteristic. The tube segment can be disposed within a housing <NUM> or other tube segment. Accordingly, the tube segment <NUM> can be filled with medicament to force the tube segment <NUM> into an expanded shape as shown. The tube segment <NUM> can be closed at either end with contoured walls <NUM> and <NUM> to reduce dead space when contracted. At least one of the contoured walls, such as contoured wall <NUM> in <FIG> can be provided with spaces or gaps where slidably contacting the housing <NUM> to provide clearance for folding sections of the tube segments <NUM> during collapse as shown in <FIG>. The filling can create a tensile force sufficient to deliver the content when released and the tube segment <NUM> contracts due to the high expansion characteristic and can fold into gaps provided in the contoured wall <NUM>. The content can be delivered through a cannula or further tube segment <NUM>.

The housing <NUM> can be sized to prevent contact with the expanding tube segment <NUM>, or the outer diameter of the tube segment <NUM> can be lubricated to allow the surface of the tube segment <NUM> to slide freely across the inner surface of the housing <NUM>. In yet another exemplary configuration, one or more of the moving wall segments in the reservoir can comprise a lubrication membrane to provide lubrication for moving elements. For example, <FIG> are cross-sectional views of such an exemplary configuration that can be used to deliver insulin or other medicament to an infusion site in accordance with an exemplary configuration.

<FIG> is a cross-sectional view of a reservoir housing <NUM> that comprises one or more moving wall segments such as the plunger or stopper <NUM> that includes a lubrication membrane <NUM> (i.e., an oil impregnated membrane) between stiff elastomer walls <NUM> and <NUM>. In the exemplary configurationshown, the moving wall segment <NUM> is a plunger or stopper of a syringe or reservoir, and provides lubrication features therein such that the remainder of the syringe or reservoir does not require a separate lubricating coating on interior walls. By impregnating O-rings, washers, disks or other porous membranes <NUM> in the plunger or stopper <NUM> with a lubricant, and designing the plunger or stopper <NUM> to release the lubricant of the porous membranes <NUM> only when dispense/inject forces are present, the moving wall of the syringe or reservoir is lubricated, but insulin or other medicament contents are not exposed to the lubricant of the porous membrane <NUM> preferably at all, and in other cases are not exposed to the lubricant of the porous membrane <NUM> until infusion begins, and exposure at that time is minimal throughout the infusion process.

To do so, the lubrication membrane <NUM> and elastomer walls <NUM> and <NUM> are configured to be driven along a central axis by a syringe engagement <NUM> when filling from a vial <NUM> as shown in <FIG>. The syringe engagement <NUM> drives the plunger or stopper <NUM> without compressing the lubrication membrane <NUM>, so that the syringe can be utilized for filling or emptying the syringe from the vial <NUM>. The syringe engagement <NUM> can be removed as shown in <FIG>, and replaced with a pump engagement <NUM> as shown in <FIG>. The pump engagement <NUM> is not configured to drive the plunger or stopper <NUM> along a central axis as with the syringe engagement <NUM>, but provides wider contact elements <NUM> extending beyond the central axis. In doing so, the wider contact elements <NUM> of the pump engagement <NUM> bear on the outer diameter of the elastomer wall <NUM> of the plunger or stopper <NUM>, deflecting the wall <NUM> into the membrane <NUM>, compressing the lubrication membrane <NUM> and releasing lubrication between the outer diameter of the plunger and the inner diameter of the reservoir as shown in <FIG>. Accordingly, the lubricant of the lubrication membrane <NUM> is only dispensed when dispense/injection forces are present, such that the insulin or other medicament contents will not be exposed to the lubricant of the porous membrane <NUM> preferably at all, and in other cases will not be exposed to the lubricant of the porous membrane <NUM> until infusion begins and exposure at that time will be minimal throughout the infusion process. These configurations described above incorporate pump features that benefit medicament or pumping operations. However, in yet other configurations, the pump can incorporate features unrelated to pumping, but which still form part of an assembly of infusion set elements which work together to deliver insulin or other medicament to an infusion site. As an example, <FIG> shows a tubing recoiler utilized as part of an infusion pump.

<FIG> is a perspective view of a tubing recoiler utilized as part of an infusion pump. An infusion pump <NUM> is shown coupled with an infusion set <NUM> via a length of tube <NUM>. However, excess tube between the infusion pump <NUM> and the infusion set <NUM> can be subject to interference and transfer undesired movement to the infusion set <NUM> through contact. Accordingly, it is desirable to minimize the length of tubing <NUM>, but provide sufficient length to ease use and placement of the infusion set <NUM>. In other systems, a separate tubing recoiler <NUM> has been provided to serve this function. However, the provision of such a separate element requires the user to carry, install and manage the separate component. Accordingly, exemplary configuration incorporate the separate tubing recoiler into the infusion pump <NUM>.

Specifically, the pump <NUM> integrates the tubing and recoiler to automatically recoil excess tubing via a spring mechanism or otherwise, and dispense tubing in a reverse manner, so that another separate device is not required to manage excess tubing. The tubing <NUM> connecting the insulin supply and pump <NUM> to the infusion set <NUM> can be packaged on a spring-loaded circular reel disposed within the pump <NUM>. The tubing <NUM> can enter and exit the pump <NUM> and wrap about a spring mechanism. Since the construction of a spring-loaded circular reel is known to those skilled in the art, additional features of such a reel are omitted for clarity. The circular reel can further comprise a catch/latch mechanism as known to those skilled in the art such that pulling the tube <NUM> a first time feeds a length of tube, and a catch is provided to prevent a reverse spring-urged action. Upon pulling the tube <NUM> a second time, the catch is released so that the reverse spring-urged action urges the tube <NUM> back into the pump <NUM>. In doing so, the reel device allows slack tubing to be fed out precisely, with spring resistance maintaining the excess tubing rolled up and stored. The locking catch or latch can be provided to allow the user to prevent inadvertent retraction or extension once a satisfactory length of tubing has been deployed.

In exemplary embodiments, the housings, hubs and other elements of the infusion system can be constructed of molded plastic materials, polycarbonate, thermoplastic polymers such as polyethylene terephthalate (PET and PETG), or similar materials. Springs and introducer needles can be constructed of stainless steel or similar materials. Although the embodiments described above are dimensioned and configured for subcutaneous injections, they can also be used for other types of injections, such as intradermal or intramuscular injections.

Further, features such as <NUM> degree rotation or partial rotation, line set connection, septum location, and so on, can be located in the strain relief rather than in the infusion set base or hub to which the Teflon cannula or catheter is secured. The strain relief can then be used to minimize the effect of line set movement or tugging, and motion that occurs at the catheter or cannula. This includes (<NUM>) tugging on the line set, as occurs when the line set catches on a door knob or other object and exerts a force to pull the infusion set from the skin, and (<NUM>) forces applied directly to the infusion hub, e.g. the patient or infusion set bumps into an object and a force is applied to the exterior of the infusion set, or the patient rolls over during sleep.

Further, one or more of the exemplary embodiments are provided with a skin contacting adhesive layer and backing. Precise insertion is achieved by first removing an adhesive cover of the adhesive layer, and then adhesively securing the infusion set hub to the infusion site via the adhesive, which permits the user to activate the inserter or place the catheter as described above at the proper alignment. Following adhesive attachment, the introducer needle, in-dwelling cannula and/or catheter is driven into the skin surface at a controlled high rate of speed to minimize the risk of misalignment at insertion. Further, the adhesive at or very near the insertion site secures the skin surface and minimizes tenting of the skin surface during insertion.

In current infusion sets which deliver insulin or other medicament to the subcutaneous layer, the catheter is usually not isolated from any undesired outside forces, which may cause pain when translated to the catheter which then moves within the skin. Also, other devices face problems of premature or unintended catheter removal when the device is bumped, if the catheter is not isolated from the outside forces. In the exemplary embodiments, the catheter can be isolated from outside forces by at least one flexible or resilient feature or strain relief.

Claim 1:
An apparatus (<NUM>) for an infusion set (<NUM>) and infusion pump comprising at least one tube (<NUM>) having a tube segment, a distal end secured to said infusion set (<NUM>) and a proximal end secured to said infusion pump, the apparatus (<NUM>) comprising:
a securing member (<NUM>) for releasably securing said tube segment between a distal end of said tube (<NUM>) and a proximal end of said tube (<NUM>); the securing member (<NUM>) comprising a circular segment of flexible material having an open portion, the circular segment is adapted to deflect to receive the tube segment and contract to secure the tube segment once received; and
a securing member base (<NUM>) comprising an adhesive layer for adhesively securing said securing member base (<NUM>) to a skin surface, wherein said securing member (<NUM>) is coupled with said securing member base (<NUM>);
wherein said securing member (<NUM>) is coupled to said securing member base (<NUM>) with a pin (<NUM>) received within the securing member base (<NUM>) and captured within an opening (<NUM>) extending through the securing member base (<NUM>) such that the pin (<NUM>) coupling permits <NUM> degree free rotation of the securing member (<NUM>) about the securing member base (<NUM>) and said securing member (<NUM>) comprises an adhesive cover (<NUM>) to adhesively secure said tube segment to said securing member (<NUM>).