Fluid delivery pump with automated cannula insertion and infusion flow control

Abstract

A fluid delivery device is provided, including infusion tubing, an insertion needle and a soft cannula, for conveying fluid from a fluid source to the soft cannula. The insertion needle is configured to guide the soft cannula forward to an extended position. The soft cannula is extendable from the insertion needle to remain in the extended position when the insertion needle is retracted. The fluid delivery device also includes an insertion torsion spring, initially held under a pre-loaded tension. Release of the pre-loaded tension causes a hammer extension to rotate, applying a linear insertion force to drive the insertion needle forward to an extended position, and, subsequently, rotating further to permit the insertion needle to be retracted from the extended position by a retraction force.

Description

FLUID DELIVERY PUMP WITH AUTOMATED CANNULA INSERTION ANDINFUSION FLOW CONTROLFIELD OF THE INVENTION

[0001] The present invention relates to the field of devices for fluid delivery, and more specifically, to a medical devices for introducing media into the body for subcutaneous or intramuscular infusion.BACKGROUND

[0002] Wearable fluid delivery devices, often referred to as delivery pumps, are becoming increasingly popular, due to the convenience they provide to patients who require drug and / or supplement injections on a regular a basis. Such devices may be affixed to the body of a patient to release a fluid (or similar injectable material) over a period of time. Delivery may be intravenous (IV), intramuscular (IM), or subcutaneous (SQ). Similarly configured fluid delivery devices also have additional applications, such as for wet lab research, industrial applications, and any other application requiring accurate, small scale fluid delivery.

[0003] Wearable fluid delivery devices are described in International Patent Publication WO2021 / 099992A2 and in PCT Patent Application PCT / IL2023 / 051040 both to Ben David, a co-inventor of the present invention. The teachings of these publications are incorporated herein by reference. The fluid delivery devices described therein include a mechanism arranged to push a plunger of a fluid cartridge forward to eject the fluid contained therein, for example, into an object, such as a user’s body. Before such fluid infusion can occur, a cannula or other tubing must be inserted. Such insertion must be safe, reliable, and easy to administer.

[0004] An additional issue associated with such wearable fluid devices is that the fluid flow can be affected by ambient air pressure changes. Mechanisms are needed to prevent flow variation due to ambient air pressure changes.SUMMARY

[0005] Embodiments of the present invention provide a system and methods for a fluid delivery pump having an integrated cannula insertion module, as well as infusion flow control during changes in ambient pressure.BRIEF DESCRIPTION OF DRAWINGS

[0006] For a better understanding of various embodiments of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings. Structural details of the invention are shown to provide a fundamental understanding of the invention, the description, taken with the drawings, making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

[0007] In the accompanying drawings:

[0008] Figs. 1A-1B are schematic illustrations of a fluid delivery device, with separate drive and delivery sections, permitting easy cartridge filling and / or replacement, according to an embodiment of the present invention;

[0009] Fig. 2 is a schematic illustration of an insertion module of the infusion section of the fluid delivery device, according to an embodiment of the present invention;

[0010] Fig. 3 is a schematic illustration of the rear side of the insertion module, according to an embodiment of the present invention;

[0011] Figs. 4-5 are schematic illustrations of a cut-away, side view of the infusion section of the fluid delivery device, including the insertion module, according to an embodiment of the present invention;

[0012] Fig. 6 is a schematic illustration showing the insertion module during cannula insertion, according to an embodiment of the present invention;

[0013] Figs. 7A-7C are schematic illustrations showing a deployment sequence of cannula insertion, according to an embodiment of the present invention;

[0014] Figs. 8-11 illustrate alternative configurations of the insertion module of the fluid delivery device, according to an embodiment of the present invention;

[0015] Fig. 12 illustrates a shutoff valve for infusion tubing, according to an embodiment of the present invention;

[0016] Fig. 13 illustrates a shutoff valve for infusion tubing, including a housing spring according to an embodiment of the present invention; and

[0017] Fig. 14 is an illustration of sealing features of the flexible wall of the infusion tubing caused by radial and axial forces applied on the flexible wall of the infusion tubing.DETAILED DESCRIPTION

[0018] It is to be understood that the invention and its application are not limited to the system and methods described below or to the arrangement of the components set forth or illustrated in the drawings, but are applicable to embodiments that may be practiced or carried out in various ways.

[0019] Figs. 1A-1B are schematic illustrations of a system 100 for fluid delivery, according to some embodiments of the present invention. A typical application of the system 100 is as a wearable device for automated drug injection, such as an insulin pump. The system 100 may include two main sections or components: a drive section 110, which receives a plunger end 122 of a vial or cartridge 120, and an infusion section 130 (also referred to as a “delivery section”). A cap end 124 of the cartridge 120 is mounted into an inlet port 132 of the infusion section 130. A drive mechanism in the drive section drives the plunger of the cartridge forward, ejecting fluid through the cap end 124. Fluid in the cartridge 120 is ejected through the infusion section 130. Once all the fluid is ejected, or a given period of time has elapsed, the cartridge may be refilled or replaced by separating the drive and delivery sections to access the cartridge. Internal elements of the infusion section, described in more detail hereinbelow, are concealed in Fig. 1A by a housing 134 of the infusion section. As described further hereinbelow, the infusion section may be configured with mechanisms for automated cannula insertion and with mechanisms for preventing pressure changes from causing an excessive infusion flow rate.

[0020] Fig. IB is a view of system 100 when the sections are attached together, such that the system is closed and ready for attachment to a surface. For an insulin pump application, a base 136 of the system 100 may be affixed to the skin of a patient, who may wear the system to apply multiple injections over time. For such an application, the deliverysection 130 as well as the cartridge 120 are typically disposed after each use in order to ensure sterility. The base 136 may include an adhesive for adhering to a patient’s skin. For some alternative applications, the delivery section 130 may be reused, that is, it is not necessarily intended to be disposed after a single use. Examples of such applications include e-cigarettes and adhesive applicators. The cartridge may alternatively be refillable. In addition, the infusion section may have a top-side adhesive patch to ensure a secure connection between the drive and infusion sections.

[0021] As described in PCT Patent Application PCT / IL2023 / 051040 to Ben David, the teachings of which are incorporated herein by reference, the drive section 110 may have a propulsion unit for forcing fluid from the cartridge, under control of a controller or similar processor, including memory for storing instructions described further hereinbelow. Additional components of the drive section may include a power source, i.e., a battery, battery charger contacts, and an audio and / or display, which may be used to convey messages to a user, such as errors or a notification that the cartridge is empty. The system may also include a communications module for communicating with an external device, such as a mobile device having an appropriately configured app that communicates instructions, such as dosing quantities, to the system controller. The mobile device app may also provide error messages to a user, for example, providing notifications of a low battery status or empty cartridge. The mobile device app may also send an instruction to the controller to advance the propulsion unit in order to prime the needle before attachment to a user’s skin.

[0022] Fig. 2 is a schematic illustration of one embodiment of an insertion module 200 of the infusion section 130 described above. The insertion module drives a soft cannula 234 forward, that is, to an extended position outside the device housing. The forward position of the soft cannula is typically in a “target zone,” such as a subcutaneous or intramuscular site of a user’s body, or a subsurface zone of other types of objects.

[0023] Insertion module 200 typically includes a module base 210, which may be mounted to the system base 136 (of Fig. 1), as well as a support bracket 220, which is mounted to the module base 210. Typically, and which supports a cartridge sleeve 222. Alternatively, the elements of the insertion module 200 may be mounted directly onto the system base 136.

[0024] The cartridge sleeve is positioned concentrically around an inlet needle 224, such that the cartridge sleeve guides a cartridge into a position wherein the cartridge cap septum is pierced by the inlet needle.

[0025] Upon insertion of a cartridge into the inlet port 132 (see Fig. 1), the cartridge cap end is positioned in the cartridge sleeve 222, and a septum of the cartridge cap end is pierced by the inlet needle 224. The inlet needle 224 is connected to infusion tubing 230, which provides a conduit for the fluid to flow from the cartridge to a soft cannula extended from the inlet needle.

[0026] The infusion tubing typically includes an insertion needle 232 (or “guide needle”). The tip of the insertion needle 232 is shown in the figure as being positioned above an insertion needle opening 254 in the module base 210. A soft cannula 234 fits over the insertion needle, such that the insertion needle extends through the hollow cavity of the soft cannula, to serve as a guide needle for insertion of the soft cannula into a target zone.

[0027] After extension of the soft cannula 234 to its extended position, the insertion needle 232 is retracted, while the soft cannula typically remains in place in its extended (“forward”) position. The soft cannula typically remains in place for the duration of a fluid injection period. Depending on the type of application, the fluid injection period may last for an extended length of time, such as several hours, or days, or more. In some examples, the soft cannula remains in place until the fluid delivery device is removed from the surface of the object, e.g., from a user’s skin.

[0028] A cam wheel 240, or other spring-loaded mechanism, may provide the driving force for moving the insertion needle forward (downward in the figure). In one embodiment, the cartridge sleeve 222 may serve as a hub around which the cam wheel 240 is mounted and rotates. An insertion torsion spring 242 (also referred to herein as a torsion spring) provides a pre-loaded rotational tension to the cam wheel. The torsion spring may be mounted around the cartridge sleeve, as shown in the figure, or mounted to the side of the cam wheel, as described further hereinbelow. A cam wheel catch 244, which may be either a protrusion or crevice in the cam wheel, may be held in place by a latch, or trigger 245, until deployment (i.e., insertion) is initiated. Releasing the trigger 245 then causes the cam wheel to rotate due to the torsion spring. Alternatively, a trigger may be configured to prevent release of the torsion spring itself until the trigger is released.

[0029] Releasing the trigger 245 frees the cam wheel to rotate under the force of the torsion spring 242. In the example shown, the cam wheel 240 has a hammer protrusion 246, also referred to herein as a hammer extension, which converts the rotational force of the torsion spring into linear force that drives the insertion needle. The hammer protrusion 246 rotates with the cam wheel to press down on an insertion bar 252. The insertion bar, positioned above the insertion needle, forces the insertion needle 232, as well as the soft cannula 236, through the insertion needle opening 254 and into the extended position.

[0030] The insertion bar 252 may be fixed to move linearly by guide elements at either side of the insertion needle. For example, the insertion bar may be guided, on one side, along a guide groove 256 in the support bracket 220, and, on the other side, by a guide shaft 258, which extends upward from the module base 210. A retraction spring 260, may be mounted to the guide shaft 258, to apply upward force on the insertion bar to retract the insertion needle after the soft cannula has been inserted, as described further hereinbelow. As the hammer protrusion 246 rotates further it slips off the insertion bar 252 (shown in Fig. 7C) causing the insertion bar 252 to move back to its original location by the force of the retraction spring 260. As noted above, the insertion needle typically extends through the length of the soft cannula. The insertion needle is affixed at its top to the insertion bar. After insertion, the soft cannula is fixed in an extended position in the body of the user, secured by one or more cannula latches 270. With the soft cannula fixed in place, the insertion needle, when retracted, slides up along the soft cannula, returning to its original position.

[0031] Hereinbelow, additional configurations are described by which a rotational torsion spring force is converted to a linear force for inserting the insertion needle. The advantage of such mechanisms that utilize rotational tension for driving the insertion is that elements of the insertion module can be positioned side-by-side on the module base, as opposed to having an insertion driving element positioned above the insertion needle. Consequently, the fluid delivery device can be designed with a low profile, making it more convenient for use as a fluid pump patch.

[0032] Fig. 3 is a schematic illustration showing a rear view of the insertion module 200, including a rear view of the support bracket 220 and the back end of the inlet needle 224 attached to the infusion tubing 230. During insertion, the infusion tubing 230 bends to a predetermined extent 310 (indicated by the dotted line), in order to follow the descent ofthe insertion bar along the guide groove 256. When the insertion needle is retracted, the infusion tubing also returns to its initial position.

[0033] Fig. 4 is a schematic illustration of a cut-away view of the infusion section 120 of the fluid delivery device 100, including the insertion module 200. Shown in the side view are the following elements also described above: the infusion section housing 134, the fluid delivery device base 136; the support bracket 220, the cartridge sleeve 222, the inlet needle 224, the infusion tubing 230, the cam wheel 240, the torsion spring 242, and the guide shaft 258 (on which is mounted the retraction spring 260, described above). When a cartridge is slid into the inlet port 132, it first presses against a cartridge seal 410. The cartridge cap end is then pierced by the inlet needle.

[0034] Fig. 5 is a schematic illustration of a cut-away view of the infusion section 120 of the fluid delivery device 100, including the insertion module 200, and showing the fluid cartridge 120 positioned in the inlet port 132. The cartridge cap end 124 is pressed into the cartridge sleeve 222, such that the inlet needle penetrates the cartridge cap end 124, allowing fluid to flow to the infusion tubing 230.

[0035] Fig. 6 is a schematic illustration showing the insertion module 200 during cannula insertion, at the point in the insertion process when the soft cannula 234 has been fully inserted and the insertion needle 232 has not yet been retracted. As shown, the cam wheel catch 244 has been released, allowing the cam wheel 240 to rotate, due to the force applied by the torsion spring 242 (i.e., the “insertion” torsion spring). The wheel catch 244 is held in place by the trigger 245. Various methods may be applied to release the cam wheel catch. In an embodiment illustrated in the figure, a release wire 602 may be configured to be pulled to release the trigger. For example, the release wire may be made of nitinol, which is deformed by application of a voltage across electrodes 604. As the nitinol wire 602 deforms, it pulls the trigger 245, which releases the wheel catch 244, thereby causing the cam wheel 240 to rotate. The voltage for the nitinol wire may be received from the drive section 110, from the controller, as described above, or from a manually operated switch. (Alternatively, the release trigger itself may be operated by a manual switch or trigger.) Also shown in Fig. 6 is cartridge snap 606. The snap is configured to allow the cartridge 120 to slide into the cartridge sleeve 222 of the input port 132 of the infusion section 130, but prevents the cartridge from been pulled out. The snap may, for example, be configured to catch the cartridge cap end 124 (described above) toprevent removal of the cartridge. Locking the cartridge into the input port of the infusion section ensures that, after use of a cartridge, a user discards both the used cartridge and the used infusion section.

[0036] Once the cam wheel is released, the hammer protrusion 246 rotates with the cam wheel, converting the rotational force of the torsion spring into a linear force, pressing down on the insertion bar 252, which forces the insertion needle 232, as well as the soft cannula 236 into the target zone.

[0037] As shown, the insertion bar 252 is guided, on one side, along the guide groove 256, and, on the other side, by the guide shaft 258, which extends upward from the module base 210 (shown mounted onto the device base 136). A retraction spring 260, mounted on the guide shaft 258, is compressed. When the hammer protrusion rotates further, as described below, to release the insertion bar, the retraction spring returns the insertion bar and the insertion needle to their original position. The soft cannula, latched by the one or more cannula latches 270 remains positioned in the target zone, while the insertion needle within the soft cannula is retracted.

[0038] Figs. 7A-7C are schematic illustrations showing a deployment sequence of cannula insertion, from a front view of the insertion module. Fig. 7A shows the cam wheel locked in an initial position by the cam wheel catch 244, which also locks the other moving elements of the insertion module, including the soft cannula 236, the hammer protrusion 246, the insertion bar 252, and the retraction spring 260.

[0039] Fig. 7B shows that after the cam wheel 240 is released, the hammer protrusion 246 rotates with the cam wheel, converting the rotational force of the torsion spring into a linear force, pressing down on the insertion bar 252. The soft cannula 236 (together with insertion needle 232), are push forward, extending out of the device, typically into a target zone (e.g., piercing a user’s skin to enter the subcutaneous or intramuscular tissue). As shown, the retraction spring 260 is compressed by the same linear force applied by the hammer protrusion.

[0040] Fig. 7C shows that as the cam wheel 240 continues its rotation, the hammer protrusion 246 releases the insertion bar 252. The soft cannula 236 remains latched in place, while the insertion bar 252, together with the insertion needle 232 are returned to their initial position by the extension of the retraction spring 260.

[0041] Figs. 8-11 illustrate alternative configurations of the infusion module of the fluid delivery device.

[0042] Fig. 8 shows a second alternative configuration of the insertion module 200, in which a side torsion spring 800 for driving the cam wheel is positioned to the side of the cartridge sleeve 222, rather than around the cartridge sleeve. Attached to the side torsion spring 800 is an insertion cog wheel 802, having cogs that mesh with cogs of the cam wheel 240. Also shown is a cog wheel catch 804 that locks not the cam wheel but the insertion cog wheel. The cog wheel catch 804, like the cam wheel catch 244 described above, may be triggered by an electric voltage applied to a electrodes 602, to move a nitinol release wire.

[0043] In some embodiments of the configuration shown in Fig. 8, a section of the circumference of the cog wheel is missing several cogs, such that the cog wheel applies a rotational force to the cam wheel during a partial revolution, and then releases the cam wheel at a point of the rotation at which the cogs are missing. Once the cam wheel cogs no longer mesh with the cog wheel, there is no force to counter the retraction spring, and the insertion needle is retracted from the extended position. The retraction spring may be configured as described above (retraction spring 260) or may be an alternative retraction mechanism as indicated in Fig. 8, in which a retraction torsion spring 806 (or retraction “band”) is wound on the cartridge sleeve together with the cam wheel.

[0044] Fig. 9 shows a third alternative configuration of the insertion module 200, in which the cam wheel 240 for inserting the insertion needle is driven by the insertion torsion spring 242, mounted on the cartridge sleeve 222, as in the first configuration described above, and, in addition, a retraction torsion spring 806, as described in the second configuration, is also mounted on the cartridge sleeve. The preloaded tension of the insertion torsion spring is maintained by a catch 244, as described above. When the cannula is inserted, the end of the insertion torsion spring 242 is radially pushed out of a slit in the cam wheel 240 hence allowing cam wheel 240 to rotate backward by the retraction torsion spring 806.

[0045] Fig. 10 shows a fourth alternative configuration of the insertion module 200, in which the cam wheel described above is replaced by a hammer torsion spring 1000, perpendicular to the axis of the cylinder sleeve, having a hammer extension 1002 thatemulates the hammer protrusion of the first configuration. The retraction spring may be configured in either of the configurations described above (retraction springs 260 or 806) or may be a retraction torsion spring 1004 on an axis common to the perpendicular torsion spring. The release of the torsion spring may use any of the trigger configurations described above, such as use of a release wire, which may, for example, be made of nitinol.

[0046] Fig. 11 shows a fifth alternative configuration of the insertion module 200, in which the rotational spring mechanisms described above are replaced by an insertion and retraction mechanism, which inserts the soft cannula 236 and then extracts the insertion needle, based on the deformation of a nitinol wire 1100. When a voltage is applied at a nitinol electrode 1102, the nitinol wire extends, causing the insertion needle to move forward for insertion. When the voltage is turned off, the nitinol wire returns to its original form, shrinking back to its former length so that a retracting spring 1104 (shown in cross section view) can pull the metal needle back (up on this view). Pulleys 1106 may be used in order to increase the total length of the nitinol wire while allowing it to move and thereby increase the total movement of the cannula.

[0047] It should be noted that the alternate configurations of the insertion module are interchangeable and substituting one for the other does not affect the operation of the rest of the fluid delivery device.

[0048] Fluid delivery from fluid delivery devices, in general, is affected by ambient air pressure, and such devices are known to have a problem of increased flow rate at reduced air pressures, for example during air travel. During a flight, the pressure within cartridge 120 may be higher than the internal body pressure of an aircraft passenger. This may increase the flow rate, raising the risk of an overdose of the fluid being provided.

[0049] Fig. 12 illustrates a shutoff valve 1200 for a length of infusion tubing for overcoming the problem of excess flow rate. According to an embodiment of the present invention, the shut-off valve 1200 is added to the infusion tubing. The shutoff valve 1200 may have a housing 1210 that may be rigid or flexible. The valve also includes an internal flexible tube 1220 having a flexible wall 1220a.

[0050] The valve has an input port (Pl) and an exit port (P2). Three pressure zones are formed and shown in Fig. 12: an upstream zone 1222 in which the pressure is similar to the pressure within the fluid cartridge, a downstream zone 1224 in which the pressure is similarto the pressure within the receiving party (e.g., the body pressure of a person injecting insulin), and a shutoff valve cavity zone 1226, i.e., the cavity between housing 1210 and the infusion tubing, shown as P0, in which the pressure is a preset pressure, which is generally set to atmospheric pressure. The media within the housing 1210 may be a gas or liquid. In case of a gas, the pressure P0 may be obtained by sealing the gas into a rigid or flexible housing. If a liquid is used, the housing 1210 should be flexible. Alternatively, an elastic element, i.e., a spring should be added to the housing, as described below with respect to Fig. 13.

[0051] As the fluid delivery device delivers fluid to the inlet port, the pressure Pl increases, causing the flexible wall 1220a to expand, overcoming the pressure of P0, so that the fluid can pass to the exit port P2. However, if the pressure at the exit port P2 decreases, the pressure in the flexible tube also decreases, such that the pressure of P0 causes the flexible wall of the tube to collapse, as shown. Consequently, the fluid cannot pass from the inlet port to the exit port.

[0052] Housing 1210 may alternatively be flexible, rather than rigid. Making the housing flexible, causes pressure P0, caused by a liquid or gas within the housing in cavity zone 1226 (between the inner tube 1220 and the elastic outer tube 1210), to change due to the effect of the elasticity of the housing. Fig. 12 may be an axisymmetric view so all elements may be tube type but may have a rectangular shape as well.

[0053] Alternatively, as shown in Fig. 13, a loaded spring 1302, with a piston 1304, may be a source of pressure, in order to maintain the pressure P0 within the housing.

[0054] Figs. 14A-14B are illustrations of a method to achieve sealing forces by applying radial and axial forces to the infusion tube, respectively. Applying radial forces to the flexible area will cause it to seal (fig 14A) while applying axial forces to the tube (fig 14B) will cause the flexible area to collapse and seal If the pressure at P2 decreases, the flexible wall of the internal tubing collapses and blocks the flow of fluid, preventing an overdose. Both radial and / or axial sealing forces may be applied to collapse the internal tubing. The radial and / or axial forces keep the flexible channel under a preloaded tension, eliminating the need for PO and ensuring a sealed channel in case of a pressure drop in P2.

[0055] EXAMPLES

[0056] An example one of the present invention, that is, a first exemplary embodimentof the invention described herein, is a fluid delivery device, including infusion tubing, and further including an insertion needle and a soft cannula, for conveying fluid from a fluid source to the soft cannula. The insertion needle is configured to guide the soft cannula forward to an extended position. The soft cannula is extendable from the insertion needle to remain in the extended position when the insertion needle is retracted. The fluid delivery device also includes an insertion torsion spring, initially held under a pre-loaded tension. Release of the pre-loaded tension causes a hammer extension to rotate, applying a linear insertion force to drive the insertion needle forward to an extended position, and, subsequently, rotating further to permit the insertion needle to be retracted from the extended position by a retraction force, for example by a retraction spring.

[0057] An example two of the present invention includes the features of example one, and the infusion tubing and the torsion spring are positioned in an infusion section of the fluid delivery device. In addition, the fluid delivery device includes a separate, attachable drive section.

[0058] An example three includes the features of either of the above examples and the infusion tubing is configured to bend to a predetermined extent during insertion of the soft cannula and to return to an initial position with retraction of the insertion needle.

[0059] An example four of the present invention has the features of any of the above examples and additionally includes a latch to catch the soft cannula upon insertion, preventing retraction of the soft cannula when the insertion needle is retracted.

[0060] An example five of the present invention has the features of any of the above examples and additionally includes a cam wheel trigger configured to maintain a cam wheel at an initial position, and wherein release of the trigger causes the cam wheel to be rotated by the insertion torsion spring to drive the insertion needle. An example six of the present invention has the features of example five, and the cam wheel trigger is released by applying an electrical voltage to a nitinol element of the trigger, changing the nitinol element shape.

[0061] An example seven of the present invention has the features of any of the above examples, and the fluid source is a fluid cartridge. The device additionally includes a cartridge sleeve for receiving the fluid cartridge, and the cartridge sleeve is a hub around which a cam wheel driven by the insertion torsion spring is mounted and rotates.

[0062] An example eight of the present invention has the features of example seven, and the torsion spring is also mounted around the cartridge sleeve.

[0063] An example nine of the present invention has the features of any of the above examples and additionally includes an insertion bar mounted on a guide shaft extending from a base of the fluid delivery interface. The hammer protrusion moves the insertion bar to drive insertion of the insertion needle.

[0064] An example ten of the present invention has the features of example nine, and the guide shaft includes the retraction spring. Movement of the insertion bar during insertion compresses the retraction spring, increasing the retraction force. In addition, the cam wheel is configured to rotate until the hammer protrusion slips off of the insertion bar to release the insertion force, and, after the release of the insertion force, the retraction force of the retraction spring lifts the insertion bar and the insertion needle.

[0065] An example eleven of the present invention has the features of any of the above examples, and the torsion spring is mounted on an axis separate and parallel to the axis of a cam wheel having the hammer protrusion. The torsion spring rotates a cog wheel that in turn rotates the cam wheel.

[0066] An example twelve of the present invention has the features of example eleven, and the cog wheel circumference has a first section with cogs that mesh with the cam wheel during insertion and a second section without cogs, thereby freeing the cam wheel from the rotational tension after the soft cannula is inserted, such that the insertion force is removed from the insertion needle and the insertion needle is retracted by the retraction spring.

[0067] An example thirteen of the present invention has the features of any of the above examples, and further includes a cartridge sleeve for receiving a fluid cartridge. The torsion spring is a first torsion spring, the retraction spring is a second torsion spring, and a cam wheel, the first torsion spring, and the second torsion spring are mounted around the cartridge sleeve.

[0068] In a further example of the invention described herein, an example 14, a fluid delivery device is provided having infusion tubing, including an insertion needle and a soft cannula, for conveying fluid from a fluid source to the soft cannula, the insertion needle being configured to guide the soft cannula forward, and the soft cannula being extendable from the insertion needle to remain at a forward position when the insertion needle isretracted. The device further includes a nitinol element. Voltage applied to the nitinol element extends the nitinol element, causing a linear insertion force to drive the insertion needle forward to an extended position, and subsequent removal of the voltage contracts the nitinol element, causing the insertion needle to be retracted from the extended position by a retraction force of a retraction spring.

[0069] In a further example of the invention described herein, an example 15, a fluid delivery device is provided for conveying fluid from a fluid source to a target zone and providing a reduced risk of excess flow due to environmental pressure drops. The fluid delivery device includes infusion tubing and a valve. The valve may enable flow from its input port to its output port when the pressure in the input port is increased. However, the valve disables flow from the input port to the output port when the pressure in the output port is decreased below atmospheric pressure (for example, during a flight).

[0070] An example sixteen of the present invention has the features of example fifteen, and flow of the fluid is controlled by gas pressure within the housing. In an example seventeen, flow of the fluid is controlled by a radial force on the tubing. In an example eighteen, flow regulation is controlled by an axial force on the tubing. In an example nineteen flow regulation is controlled by liquid pressure exerted on the tubing. In an example twenty, flow regulation is controlled by liquid or gas pressure caused by a springmounted piston connected to the housing. Flow may also be controlled by a combination of the above means.

[0071] In a further example of the invention described herein, an example 21,

[0072] It is to be understood that the scope of the present invention includes variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art. Although the invention has been described in detail, nevertheless, changes and modifications, which do not depart from the teachings of the present invention, will be evident to those skilled in the art. Such changes and modifications are deemed to come within the purview of the present invention and the appended claims.

[0073] It will be readily apparent that the various methods and algorithms described with respect to the controller may be implemented by appropriately programmed general purpose computers and other types of computing devices. Furthermore, programs thatimplement such methods and algorithms may be stored and transmitted using a variety of media in a number of manners. In some embodiments, hard-wired circuitry or custom hardware may be used in place of, or in combination with, software instructions for implementation of the processes of various embodiments. Thus, embodiments are not limited to any specific combination of hardware and software. Transmission media include coaxial cables, copper wire and fiber optics, including wires that comprise a bus coupled to the processor. Transmission media may include or convey acoustic waves, light waves and electromagnetic emissions, such as those generated during radio frequency (RF) and infrared (IR) data communications. Instructions may be delivered from memory to the processor carried over a wireless transmission medium, and / or may be formatted according to numerous formats, standards or protocols, such as Bluetooth, TDMA, CDMA, 3G.

[0074] The following is a table of elements referenced in the above specification of the present invention:

Claims

CLAIMS1. A fluid delivery device, comprising: infusion tubing, including an insertion needle and a soft cannula, for conveying fluid from a fluid source to the soft cannula, wherein the insertion needle is configured to guide the soft cannula to an extended position, and wherein the soft cannula is extendable from the insertion needle to remain in the extended position when the insertion needle is retracted; an insertion torsion spring, initially held under a pre-loaded tension, wherein release of the pre-loaded tension causes a hammer extension to rotate, applying a linear insertion force to drive the insertion needle forward to an extended position, and, subsequently, rotating further to a position permitting the insertion needle to be retracted from the extended position by a retraction force of a retraction spring.

2. The fluid delivery device of claim 1, wherein the infusion tubing and the torsion spring are positioned in an infusion section of the fluid delivery device, and wherein the fluid delivery device includes a separate, attachable drive section including a mechanism for ejecting fluid from the fluid source.

3. The fluid delivery device of claim 1, wherein the infusion tubing is configured to bend to a predetermined extent during insertion of the soft cannula and to return to an initial position with retraction of the insertion needle.

4. The fluid delivery device of claim 1, further comprising a latch to catch the soft cannula upon insertion, preventing retraction of the soft cannula when the insertion needle is retracted.

5. The fluid delivery device of claim 1, further comprising a trigger configured to maintain the torsion spring at an initial position, and wherein release of the catch causes the torsion spring to cause the hammer extension to drive the insertion needle.

6. The fluid delivery device of claim 5, wherein the trigger is released by applying a voltage to a nitinol element, changing the nitinol element shape or length.

7. The fluid delivery device of claim 1, further comprising a cam wheel, wherein the hammer extension is an element of the cam wheel, and wherein release of a catch causesthe torsion spring to rotate the cam wheel, causing the hammer extension to drive the insertion needle.

8. The fluid delivery device of claim 1, wherein the fluid source is a fluid cartridge, and wherein the fluid delivery device further comprises a cartridge sleeve for receiving the fluid cartridge, wherein the cartridge sleeve is a hub around which a cam wheel driven by the torsion spring is mounted and rotates.

9. The fluid delivery device of claim 8, wherein the torsion spring is also mounted around the cartridge sleeve.

10. The fluid delivery device of claim 1, further comprising an insertion bar mounted on a guide shaft extending from a base of the fluid delivery interface, wherein the hammer protrusion moves the insertion bar to drive insertion of the insertion needle.

11. The fluid delivery device of claim 10, wherein the guide shaft includes the retraction spring, wherein movement of the insertion bar during insertion compresses the retraction spring, increasing the retraction force, wherein a cam wheel is configured to rotate until the hammer protrusion slips off of the insertion bar to release the insertion force, and wherein, after the release of the insertion force, the retraction force of the retraction spring lifts the insertion bar and the insertion needle.

12. The fluid delivery device of claim 1, wherein the torsion spring is mounted on an axis separate and parallel to the axis of a cam wheel including the hammer extension, wherein the torsion spring rotates a cog wheel that in turn rotates the cam wheel and the hammer extension.

13. The fluid delivery device of claim 12, wherein the cog wheel has a first section with cogs that mesh with the cam wheel during insertion and a second section without cogs, thereby freeing the cam wheel from the rotational tension after the soft cannula is inserted, such that the insertion force is removed from the insertion needle and the insertion needle is retracted by the retraction spring.

14. The fluid delivery device of claim 1, further comprising a cartridge sleeve for receiving a fluid cartridge, wherein the torsion spring is a first torsion spring, wherein the retraction spring is a second torsion spring, and wherein a cam wheel driven by the first torsion spring,as well as the first torsion spring and the second torsion spring are mounted around the cartridge sleeve.

15. A fluid delivery device, comprising: infusion tubing, including an insertion needle and a soft cannula, for conveying fluid from a fluid source to the soft cannula, wherein the insertion needle is configured to guide the soft cannula forward, and wherein the soft cannula is extendable from the insertion needle to remain at a forward position when the insertion needle is retracted; and a nitinol element, wherein electrical current applied to the nitinol element extends the nitinol element, causing a linear insertion force to drive the insertion needle forward to an extended position, and, wherein subsequent removal of the voltage contracts the nitinol element, the insertion needle to be retracted from the extended position by a retraction force of a retraction spring.

16. A valve of a fluid delivery device, wherein the fluid delivery device conveys fluid from a fluid source to a cannula through infusion tubing, the valve comprising: a housing having an input port and an output port, wherein the infusion tubing passes through the housing from the input port to the output port, and wherein pressure applied to the infusion tubing inside the housing disables flow of the fluid when external pressure drops below a threshold.

17. The valve of claim 16, wherein flow of the fluid is controlled by gas or liquid pressure within the housing exerted on the infusion tubing.

18. The valve of claim 16, wherein flow of the fluid is controlled by one or both of a radial force and an axial force on the infusion tubing.

19. The valve of claim 16, wherein flow regulation is controlled by liquid or gas pressure caused by a spring-mounted piston or other elastomer connected to the housing.

20. A fluid delivery device comprising: an infusion section, having an input port for receiving a cap end of a fluid cartridge, and having infusion tubing for conveying fluid from the cartridge to a cannula; a detachable drive section, for receiving the plunger end of the cartridge and comprising a drive mechanism for ejecting fluid from the cartridge; and a snap configured to lock the cartridge into the infusion section.

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