Rotary Metering Gasket Pump

Abstract

A rotary pump for a fluid metering system is provided, the rotary pump reciprocating and reversed by a signal from a limit switch deflected by an actuator arm on a rotating sleeve of the pump system, the sleeve receiving a gasket that forms a seal between the sleeve and a housing, the gasket having an opening surrounding a side hole in the sleeve allowing fluid to pass through the side hole between the pump volume and an inlet or outlet port of the housing.

Description

[Technical Field]

[0001] The present invention relates generally to a metering system for use in wearable drug infusion patches. [Background technology]

[0002] This application is a continuation-in-part of U.S. patent application Ser. No. 15 / 300,695, filed September 29, 2016, which is a U.S. national stage application of International Application No. PCT / US2015 / 024517, filed April 6, 2015, and is related to U.S. patent application Ser. No. 16 / 521,685, filed July 25, 2019, which claims priority to U.S. provisional application Ser. No. 61 / 976,361, filed April 7, 2014.

[0003] Diabetes is a group of diseases characterized by high blood glucose levels due to defects in insulin production, insulin action, or both. Diabetes can lead to serious health complications and premature death, but there are well-known products available to people with diabetes to help control the disease and reduce the risk of complications.

[0004] Treatment options for people with diabetes include special diets, oral medications, and / or insulin therapy. The primary goal of diabetes treatment is to control a patient's blood sugar levels to increase the chances of living a complication-free life. However, achieving good diabetes control while balancing other life demands and circumstances is not always easy.

[0005] Currently, there are two primary modes of daily insulin therapy for the treatment of type 1 diabetes. The first mode involves syringes and insulin pens, which typically require needle insertion for each of three to four injections per day. These devices are easy to use and relatively low-cost. Another widely adopted and effective treatment for managing diabetes is the use of insulin pumps. Insulin pumps help users maintain blood glucose levels within a target range based on their individual needs by continuously infusing insulin at varying rates to more closely mimic the behavior of the pancreas. Using an insulin pump allows users to tailor their insulin therapy to their lifestyle, rather than adapting their lifestyle to how insulin injections work for them.

[0006] However, conventional insulin pumps suffer from several drawbacks, including the lead screw and piston-type metering systems typically used in insulin pumps, which require significant height and a large footprint and are often cumbersome for users.

[0007] Additionally, conventional insulin pumps typically require numerous components and moving parts, which increases the risk of mechanical failure.

[0008] Also, conventional insulin pumps typically have tolerance loops that are too long for dose accuracy, depending on too many factors, and can be difficult to verify, which can lead to loss of dose accuracy.

[0009] Additionally, conventional insulin pumps typically have overly complicated fluid paths, which can make priming and air removal complicated or inefficient.

[0010] Additionally, conventional insulin pumps typically require high precision actuators, which increases the cost of conventional patch pumps.

[0011] Some insulin pumps also run the risk of creating a direct fluid path between the insulin patch reservoir and the cannula, which could result in the user overdosing.

[0012] Additionally, conventional insulin pumps typically require complex sensing schemes, which can increase cost and reduce accuracy and reliability.

[0013] Conventional insulin pumps also typically have valves that are prone to leaking at elevated system backpressures, which can reduce accuracy and reliability.

[0014] Additionally, conventional insulin pumps typically require large working volumes and large system volumes that are subject to potentially high backpressures, which can reduce accuracy and reliability.

[0015] Also, conventional insulin patches typically have inefficient motors that require large batteries, thereby increasing the size of the insulin patch.

[0016] Therefore, there is a need for a weighing system that has a reduced height and footprint compared to conventional lead screw and piston type weighing systems to improve user comfort.

[0017] There is also a need for a metering system that has fewer components and moving parts compared to conventional insulin pumps to improve the mechanical safety of the insulin patch.

[0018] There is also a need for a metering system that has a shorter tolerance loop for dose accuracy that is dependent on fewer factors than conventional metering pumps, thereby improving dose accuracy.

[0019] There is also a need for a metering system that provides a simple fluid path compared to conventional metering systems, thereby simplifying priming and air removal.

[0020] There is also a need for a metering system that utilizes a less precise actuator compared to conventional metering systems, thereby reducing the cost of the insulin patch.

[0021] There is also a need for a metering system that, compared to conventional metering systems, does not have a direct fluid path between the reservoir and the cannula, thereby better protecting the user from overdose.

[0022] There is also a need for a metering system that provides a simplified detection scheme compared to conventional metering systems, thereby reducing costs and improving accuracy and reliability of insulin patches.

[0023] There is also a need for a metering system that provides a valve that is more robust to leakage at elevated system back pressures than conventional metering systems, thereby increasing the accuracy and reliability of the insulin patch.

[0024] There is also a need for a metering system that has a small working volume and a small system volume that is subject to potentially high back pressure compared to conventional metering systems, thereby improving the accuracy and reliability of the insulin patch.

[0025] There is also a need for a metering system that requires a high efficiency motor with a small battery compared to conventional metering systems, thereby reducing the size of the insulin patch. Summary of the Invention [Problem to be solved by the invention]

[0026] SUMMARY OF THE INVENTION It is an aspect of exemplary embodiments of the present invention to substantially address the above and other problems and to provide a compact, reliable metrology system. [Means for solving the problem]

[0027] One aspect of the exemplary embodiment is to reduce complexity and eliminate the need for interlocking mechanisms. A further aspect of the exemplary embodiment is to increase insulin compatibility by reducing shear between surfaces where insulin may be trapped.

[0028] These and other aspects of the present disclosure are realized by providing a rotary metering pump including a sleeve with a side hole. The sleeve receives a gasket having a first gasket opening disposed about the side hole. The sleeve and gasket are adapted for axial rotation within a housing having an inlet port connected to a fluid reservoir and an outlet port connected to a delivery cannula. The sleeve further includes a helical groove having a first end and a second end. The pump also includes a plunger received within the sleeve and adapted for rotation and axial translation within the sleeve, where axial translation of the plunger within the sleeve varies a pump volume, the pump volume being in fluid communication with the side hole of the sleeve. The plunger further includes a coupling member adapted to move within the helical groove and between the first and second ends of the helical groove and to axially translate the plunger within the sleeve as the plunger rotates. The motor is adapted to rotate the plunger in a first direction to increase the pump volume when the sleeve is in a first orientation, and to rotate the sleeve and plunger together when the coupling member reaches the first end of the spiral groove, causing the sleeve to move to a second orientation. The output gear transmits the motor's motion to the plunger. The gasket forms a seal between the sleeve and the housing, allowing fluid to pass through the first gasket opening between the pump volume and the inlet or outlet port. [Brief explanation of the drawings]

[0029] Various objects, advantages and novel features of illustrative embodiments of the present invention will be more readily understood from the following detailed description when read in conjunction with the accompanying drawings.

[0030] [Figure 1] 1 is a diagram illustrating the configuration of an exemplary embodiment of a patch pump according to the present invention. [Figure 2] FIG. 1 illustrates the layout of fluid and metering system components of an exemplary embodiment of a patch pump according to the present invention. [Figure 3] FIG. 2 is a schematic exploded view illustrating the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 4] 1 is a layout illustrating the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 5] 1 is a schematic cross-sectional view illustrating a metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 6A] 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention, showing the starting position. [Figure 6B] 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention, showing the starting position. [Figure 7A] 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention, showing the metering subsystem during an inspiratory stroke. [Figure 7B] 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention, showing the metering subsystem during an inspiratory stroke. [Figure 8A] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an inspiratory stroke. [Figure 8B] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an inspiratory stroke. [Figure 8C] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an inspiratory stroke. [Figure 9A] 10A-10C are multiple views illustrating the inspiratory transition stop position of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 9B] 10A-10C are multiple views illustrating the inspiratory transition stop position of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 10A] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during an ejection stroke. [Figure 10B] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during an ejection stroke. [Figure 11A] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an exhaust stroke. [Figure 11B] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an exhaust stroke. [Figure 11C] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an exhaust stroke. [Figure 12A] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention after a pump cycle is completed. [Figure 12B] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention after a pump cycle is completed. [Figure 13] FIG. 1 is an exploded view illustrating the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 14] 1 is a schematic exploded view illustrating a pump assembly of an exemplary embodiment of a metering pump according to the present invention. [Figure 15] FIG. 2 is a schematic exploded view illustrating the motor and gearbox assembly of an exemplary embodiment of a metering pump according to the present invention. [Figure 16A] 10A-10C are several schematic diagrams illustrating how the piston is assembled into the sleeve according to the present invention. [Figure 16B] 10A-10C are several schematic diagrams illustrating how the piston is assembled into the sleeve according to the present invention. [Figure 16C] 10A-10C are several schematic diagrams illustrating how the piston is assembled into the sleeve according to the present invention. [Figure 16D] 10A-10C are several schematic diagrams illustrating how the piston is assembled into the sleeve according to the present invention. [Figure 17A] 10A-10C are several schematic diagrams illustrating how a plug may be assembled into a sleeve in accordance with the present invention. [Figure 17B] 10A-10C are several schematic diagrams illustrating how a plug may be assembled into a sleeve in accordance with the present invention. [Figure 17C] 10A-10C are several schematic diagrams illustrating how a plug may be assembled into a sleeve in accordance with the present invention. [Figure 18A] 10A-10C are several schematic diagrams illustrating how a sleeve may be incorporated into a manifold in accordance with the present invention. [Figure 18B] 10A-10C are several schematic diagrams illustrating how a sleeve may be incorporated into a manifold in accordance with the present invention. [Figure 18C] 10A-10C are several schematic diagrams illustrating how a sleeve may be incorporated into a manifold in accordance with the present invention. [Figure 18D] 10A-10C are several schematic diagrams illustrating how a sleeve may be incorporated into a manifold in accordance with the present invention. [Figure 19] 1 is a schematic cross-sectional view of a pump assembly of an exemplary embodiment of a patch pump according to the present invention. [Figure 20A] 1 is a schematic cross-sectional view illustrating a method of valve state change according to the present invention; [Figure 20B] 1 is a schematic cross-sectional view illustrating a method of valve state change according to the present invention; [Figure 20C] 1 is a schematic cross-sectional view illustrating a method of valve state change according to the present invention; [Figure 20D] 1 is a schematic cross-sectional view illustrating a method of valve state change according to the present invention; [Figure 20E] 1 is a schematic cross-sectional view illustrating a method of valve state change according to the present invention; [Figure 21A]10A-10C illustrate multiple views of limit switches for pump and sleeve rotation in the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 21B] 10A-10C illustrate multiple views of limit switches for pump and sleeve rotation in the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 21C] 10A-10C illustrate multiple views of limit switches for pump and sleeve rotation in the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 22A] 10A-10C are a number of schematic cross-sectional views illustrating how a pump according to the present invention can be incorporated into a gearbox. [Figure 22B] 10A-10C are a number of schematic cross-sectional views illustrating how a pump according to the present invention can be incorporated into a gearbox. [Figure 22C] 10A-10C are a number of schematic cross-sectional views illustrating how a pump according to the present invention can be incorporated into a gearbox. [Figure 23A] 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention, showing the starting position. [Figure 23B] 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention, showing the starting position. [Figure 23C] 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention, showing the starting position. [Figure 24A] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during an ejection stroke. [Figure 24B] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during an ejection stroke. [Figure 25A] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an exhaust stroke. [Figure 25B] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an exhaust stroke. [Figure 25C] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an exhaust stroke. [Figure 26A] 10A-10C are multiple views illustrating the ejection rotation stop position of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 26B] 10A-10C are multiple views illustrating the ejection rotation stop position of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 27A] 1A-1C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during an intake stroke. [Figure 27B] 1A-1C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during an intake stroke. [Figure 28A] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an intake stroke. [Figure 28B] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an intake stroke. [Figure 28C] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention during a valve state change after an intake stroke. [Figure 29A] 10A-10C are multiple views illustrating the inhalation rotation stop position of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 29B] 10A-10C are multiple views illustrating the inhalation rotation stop position of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention. [Figure 30A] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention after a pump cycle is completed. [Figure 30B] 10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention after a pump cycle is completed. [Figure 30C]10A-10C illustrate multiple views of the metering subsystem of an exemplary embodiment of a patch pump according to the present invention after a pump cycle is completed. [Figure 31A] 1A-1C are several views illustrating the motor and gearbox assembly and improved pump assembly of an exemplary embodiment of a metering assembly according to the present invention. [Figure 31B] 1A-1C are several views illustrating the motor and gearbox assembly and improved pump assembly of an exemplary embodiment of a metering assembly according to the present invention. [Figure 31C] 1A-1C are several views illustrating the motor and gearbox assembly and improved pump assembly of an exemplary embodiment of a metering assembly according to the present invention. [Figure 32] FIG. 2 is an exploded view of a pump assembly of an exemplary embodiment of a metering assembly according to the present invention. [Figure 33A] 10A-10C illustrate the incorporation of a piston into a sleeve of an exemplary embodiment of a patch pump according to the present invention. [Figure 33B] 10A-10C illustrate the incorporation of a piston into a sleeve of an exemplary embodiment of a patch pump according to the present invention. [Figure 34A] 10A-10C illustrate the incorporation of a sleeve into a manifold of an exemplary embodiment of a patch pump according to the present invention. [Figure 34B] 10A-10C illustrate the incorporation of a sleeve into a manifold of an exemplary embodiment of a patch pump according to the present invention. [Figure 34C] 10A-10C illustrate the incorporation of a sleeve into a manifold of an exemplary embodiment of a patch pump according to the present invention. [Figure 34D] 10A-10C illustrate the incorporation of a sleeve into a manifold of an exemplary embodiment of a patch pump according to the present invention. [Figure 34E] 10A-10C illustrate the incorporation of a sleeve into a manifold of an exemplary embodiment of a patch pump according to the present invention. [Figure 35]1 is a cross-sectional view of an exemplary embodiment of a patch pump according to the present invention showing a sleeve and manifold assembly. [Figure 36A] 10A-10C are multiple cross-sectional views illustrating valve state changes of an exemplary embodiment of a patch pump according to the present invention as the sleeve rotates. [Figure 36B] 10A-10C are multiple cross-sectional views illustrating valve state changes of an exemplary embodiment of a patch pump according to the present invention as the sleeve rotates. [Figure 36C] 10A-10C are multiple cross-sectional views illustrating valve state changes of an exemplary embodiment of a patch pump according to the present invention as the sleeve rotates. [Figure 37A] 10A-10C illustrate a sleeve rotation limit switch of an exemplary embodiment of a patch pump according to the present invention. [Figure 37B] 10A-10C illustrate a sleeve rotation limit switch of an exemplary embodiment of a patch pump according to the present invention. [Figure 37C] 10A-10C illustrate a sleeve rotation limit switch of an exemplary embodiment of a patch pump according to the present invention. [Figure 37D] 10A-10C illustrate a sleeve rotation limit switch of an exemplary embodiment of a patch pump according to the present invention. [Figure 38A] 1A and 1B are exploded views of an exemplary embodiment of a patch pump according to the present invention showing the pump assembly with elastomeric ports and piston seals overmolded onto the manifold and pump piston, respectively. [Figure 38B] 1A and 1B are exploded views of an exemplary embodiment of a patch pump according to the present invention showing the pump assembly with elastomeric ports and piston seals overmolded onto the manifold and pump piston, respectively. [Figure 39A] 1 is an exploded view of an exemplary embodiment of a patch pump according to the present invention showing a pump assembly with an alternative rotational limit switch design. [Figure 39B] 1 is an exploded view of an exemplary embodiment of a patch pump according to the present invention showing a pump assembly with an alternative rotational limit switch design. [Figure 39C] 1 is an exploded view of an exemplary embodiment of a patch pump according to the present invention showing a pump assembly with an alternative rotational limit switch design. [Figure 39D] 1 is an exploded view of an exemplary embodiment of a patch pump according to the present invention showing a pump assembly with an alternative rotational limit switch design. [Figure 40] 1 is an exploded view of an exemplary embodiment of a weighing assembly according to the present invention. [Figure 41] FIG. 41 is an assembled view of the weighing assembly of FIG. 40. [Figure 42] FIG. 41 shows a cross section of the weighing assembly of FIG. 40. [Figure 43A] 41 illustrates the interaction of the sleeve and interlock of the weighing assembly of FIG. 40 in accordance with an exemplary embodiment of the present invention. [Figure 43B] 41 illustrates the interaction of the sleeve and interlock of the weighing assembly of FIG. 40 in accordance with an exemplary embodiment of the present invention. [Figure 43C] 41 illustrates the interaction of the sleeve and interlock of the weighing assembly of FIG. 40 in accordance with an exemplary embodiment of the present invention. [Figure 44] 10 is a cross-sectional view of another exemplary embodiment of a weighing assembly according to the present invention. [Figure 45] FIG. 10 is an isometric view of a limit switch and actuator arm useful in an alternative exemplary embodiment of the present invention. [Figure 46] FIG. 46 is an isometric view of the limit switch and rotating sleeve according to the embodiment of FIG. 45. [Figure 47] FIG. 46 is a top view of the limit switch of FIG. 45. [Figure 48] FIG. 46 is a top view of the limit switch and actuator arm of FIG. [Figure 49] FIG. 47 is an end view of the rotating sleeve of FIG. 46. [Figure 50] FIG. 46 is a cross-sectional elevation view of the limit switch and actuator arm of FIG. [Figure 51A]10 is a graph illustrating the relative displacement of a limit switch and a rotating sleeve in accordance with an exemplary embodiment of the present invention. [Figure 51B] 10 is a graph illustrating the relative displacement of a limit switch and a rotating sleeve in accordance with an exemplary embodiment of the present invention. [Figure 52] 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. [Figure 53] 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. [Figure 54] 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. [Figure 55] 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. [Figure 56] 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. [Figure 57] 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. [Figure 58] 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. [Figure 59] 59 is a different perspective view of an overmolded seal for the improved plunger of FIGS. 52-58. FIG. [Figure 60] 59 is a different perspective view of an overmolded seal for the improved plunger of FIGS. 52-58. FIG. [Figure 61] 59 is a different perspective view of an overmolded seal for the improved plunger of FIGS. 52-58. FIG. [Figure 62] 59 is a different perspective view of an overmolded seal for the improved plunger of FIGS. 52-58. FIG. [Figure 63] 10A-10C are different perspective views of the improved pump plug. [Figure 64] 10A-10C are different perspective views of the improved pump plug. [Figure 65]10A-10C are different perspective views of the improved pump plug. [Figure 66] 10A-10C are different perspective views of the improved pump plug. [Figure 67] 10A-10C are different perspective views of the improved pump plug. [Figure 68] FIG. 1 is an exploded view of a pump system utilizing the improved plunger, plug and overmolded seal of an exemplary embodiment of the present invention. [Figure 69] 4 is a flowchart of a method for manufacturing a pump according to an exemplary embodiment of the present invention. [Figure 70A] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70B] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70C] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70D] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70E] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70F] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70G] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70H] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70I] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70J] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70K] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 70L] 1 illustrates an end view of a shuttle interlock pump in accordance with an exemplary embodiment of the present invention. FIG. [Figure 71] FIG. 70B is an exploded view of the components of the shuttle interlock pump of FIGS. 70A-70L. [Figure 72A] 72A to 72D are diagrams illustrating the operation of the shuttle interlock pumps of FIGS. 70A to 70L and 71. FIG. [Figure 72B] 72A to 72D are diagrams illustrating the operation of the shuttle interlock pumps of FIGS. 70A to 70L and 71. FIG. [Figure 72C] 72A to 72D are diagrams illustrating the operation of the shuttle interlock pumps of FIGS. 70A to 70L and 71. FIG. [Figure 73] FIG. 10 is an exploded view of another embodiment of the present invention. [Figure 74] FIG. 74 is a perspective view of the embodiment shown in FIG. 73. [Figure 75] FIG. 74 is a cross-sectional view of the embodiment of FIG. 73. [Figure 76] FIG. 74 is a perspective view of the embodiment of FIG. 73. [Figure 77] FIG. 74 is a perspective view of the embodiment of FIG. 73. [Figure 78] FIG. 74 is a cross-sectional view of the embodiment of FIG. 73. [Figure 79] FIG. 74 is a cross-sectional view of the embodiment of FIG. 73. [Figure 80] FIG. 74 shows a gasket for use in the pump shown in FIG. 73. [Figure 81] FIG. 74 shows an alternative gasket for use with the pump shown in FIG. 73. [Figure 82] 82 shows the embodiment of FIG. 73 using the alternative gasket of FIG. 81. FIG.

[0031] It should be understood that throughout the drawings, like reference numerals refer to like elements, features and structures. DETAILED DESCRIPTION OF THE INVENTION

[0032] As will be appreciated by those skilled in the art, there are many ways of implementing examples, modifications, and configurations of a metering system in accordance with the disclosed inventive embodiments disclosed herein. Although reference will be made to the exemplary embodiments shown in the drawings and the following description, the embodiments disclosed herein are not exhaustive of the various alternative designs and embodiments encompassed by the disclosed invention, and those skilled in the art will readily appreciate that various modifications can be made and various combinations can be made without departing from the invention.

[0033] Although various persons, including but not limited to a patient or healthcare professional, may operate or use exemplary embodiments of the invention according to the present disclosure, for the sake of brevity, the operator or user will hereinafter be referred to as the "user."

[0034] Although various fluids may be used in exemplary embodiments of the presently disclosed invention, for simplicity, the liquid within the injection device will hereinafter be referred to as the "fluid."

[0035] Exemplary embodiments according to the present invention are shown in Figures 1-30. In exemplary embodiments according to the present invention, a metering system for use in a wearable insulin infusion patch is provided. For example, in exemplary embodiments of the present invention, the metering system is part of a larger fluidics subsystem that includes a flexible reservoir for storing insulin and a cannula assembly for delivering the insulin to subcutaneous tissue. The metering system draws a small amount of fluid from the reservoir and then pushes it down the cannula line and into the patient. The fluid dose is small relative to the reservoir volume, and many pump strokes are required to completely empty the reservoir.

[0036] 1 shows a diagram of a configuration of a patch pump 100 according to an exemplary embodiment of the invention. Patch pump 100 includes a fluidics subsystem 120, an electronics subsystem 140, and a power storage subsystem 160.

[0037] The fluidics subsystem 120 includes a fill port 122 in fluid communication with a reservoir 124. The reservoir 124 is adapted to receive fluid from a syringe through the fill port.

[0038] The fluidics subsystem 120 further includes a volume sensor 126 mechanically coupled to the reservoir 124. The volume sensor 126 is adapted to detect or determine the fluid volume of the reservoir.

[0039] The fluidics subsystem 120 further includes a metering subsystem 130 that includes an integrated pump and valve system 132 mechanically coupled to a pump and valve actuator 134. The integrated pump and valve system 132 is in fluid communication with the reservoir 124 of the fluidics subsystem 120 and is actuated by the pump and valve actuator 134.

[0040] The fluidics subsystem 120 further includes a cannula mechanism having a deployment actuator 128 mechanically coupled to a cannula 129. The deployment actuator 128 is adapted to insert the cannula 129 into a user. The cannula 129 is in fluid communication with an integrated pump and valve system 132 of the metering subsystem 130.

[0041] Fluidics subsystem 120 further includes an occlusion sensor 136 mechanically coupled to a fluid pathway between cannula 129 and integrated pump and valve system 132. Occlusion sensor 136 is adapted to detect or determine an occlusion in the pathway between cannula 129 and integrated pump and valve system 132.

[0042] The electronics subsystem 140 includes volume sensing electronics 142 electrically coupled to the volume sensor 126 of the fluidics subsystem 120, a pump and valve controller 144 electrically coupled to the pump and valve actuator 134 of the metering subsystem, occlusion detection electronics 146 electrically coupled to the occlusion sensor 136 of the fluidics subsystem 120, and optional deployment electronics 148 electrically coupled to the cannula 129 of the fluidics subsystem. The electronics subsystem 140 further includes a microcontroller 149 electrically coupled to the volume sensing electronics 142, the pump and valve controller 144, the occlusion detection electronics 146, and the deployment electronics 148.

[0043] Power storage subsystem 160 includes a battery 162 or any other power source known in the art. Battery 162 can be adapted to power any element or electronic component of patch pump 100.

[0044] 2 shows the layout of fluid and metering system components of a patch pump 200 in accordance with an exemplary embodiment of the invention. Patch pump 200 includes a metering subsystem 230, control electronics 240, a battery 260, a reservoir 222, a fill port 224, and a cannula mechanism 226. The elements of patch pump 200 are substantially similar to, and interact in a substantially similar manner with, elements of exemplary patch pump 100 referenced by like reference numbers.

[0045] 3 is an exploded perspective view of a metering subsystem 300 of a patch pump in accordance with an exemplary embodiment of the present invention. The metering subsystem 300 includes a DC gear motor 302 mechanically coupled to a pump piston 304 disposed within a pump casing 306. The pump piston 304 is mechanically coupled to a pump housing 308 by a coupling pin 310. The metering subsystem 300 further includes a pump seal 312 between the pump piston 304 and the pump housing 308. The metering subsystem 300 further includes a port seal 314 on a seal carriage 316 disposed within a valve housing 318.

[0046] In an exemplary embodiment of the invention, the DC gear motor output shaft 320 is capable of rotating 360 degrees in either direction. The pump piston 304 is capable of rotating 360 degrees in either direction and translating approximately 0.050 inches. The pump housing 308 is capable of rotating 180 degrees in either direction. The pump casing 306, port seal 314, seal carriage 316, and valve housing 318 are preferably stationary.

[0047] The metering subsystem 300 includes a positive displacement pump with an integrated flow control valve, mechanical actuator, and drive system. The pump includes a piston and a rotary-actuated selector valve. The metering system draws a precise volume of insulin from a flexible reservoir into a pump volume 320 formed between the piston 304 and the pump housing 308 (see FIG. 5 ). This volume of insulin is then expelled through a cannula into the patient's subcutaneous tissue, delivering small, discrete doses of insulin. The pump stroke creates positive and negative pressure gradients in the fluid path to induce flow. The stroke and internal diameter of the pump volume determine the dose accuracy and nominal size. A fluid control valve actively shuttles between the reservoir and the cannula's fluid ports at both ends of the pump stroke, alternately closing and opening the ports to ensure unidirectional fluid flow (from the reservoir to the patient) and no free flow between the reservoir and the patient.

[0048] 4 is an assembly view of the metering subsystem 300 in accordance with an exemplary embodiment of the present invention, also showing the motor-to-piston connection 322, the piston-to-pump housing connection 324, the reservoir port 326, and the cannula port 328.

[0049] 5 is a cross-sectional view of metering subsystem 300 of an exemplary embodiment of the invention. As shown, pump volume 320 is formed between the piston and pump housing 308. The pump housing includes a side port 330 that alternates in orientation between reservoir port 326 and cannula port 328 as the motor reciprocates the pump, as described in more detail below.

[0050] In operation, an exemplary cycle of a metering system according to the present invention includes four steps: 180° pump intake (counterclockwise) (looking from the pump towards the motor), 180° valve state change (counterclockwise), 180° pump exhaust (clockwise), and 180° valve state change (clockwise). A complete cycle requires a full rotation (360°) in each direction.

[0051] 6A is an isometric view and FIG. 6B is a cross-sectional view of the metering subsystem 300 in a starting position. In the starting position, the pump piston 30 4 is fully extended, the pump housing closes the cannula port flow path at the cannula port 328, the reservoir port 326 opens to a side port 330 in the pump housing 308, and the rotation limit sensor 332 is engaged. The pump housing 308 includes a helical groove 334 that receives the coupling pin 310. The piston 304 is in sliding engagement with the pump housing 308, and as the piston 304 rotates within the pump housing 308 (by the rotational force of the motor 302), the coupling pin 310 slides along the helical groove 334, compressing the piston 304 and axially translating it relative to the pump housing 308. In this embodiment, the helical groove 334 is formed in the pump housing 308 and provides 180° of rotation for the coupling pin 310.

[0052] FIG. 7A is an isometric view, and FIG. 7B is a cross-sectional view of the metering subsystem 300 during the intake stroke. The DC motor 302 rotates the pump piston 304, which is driven (rotates and translates) along a helical groove 334 in the pump housing 308 via a coupling pin 310. The pump piston 304 translates toward the DC motor 302, drawing fluid into the increasing pump volume 320. During the intake stroke, friction between the seal and the outer diameter of the pump housing 308 is preferably high enough to prevent the pump housing 308 from rotating. The pump housing 308 is stationary, while the pump volume 320 is expanding. The cannula port 328 is closed, but the reservoir port 326 is open to fluid entering the expanding pump volume 320. There is a sliding engagement between the motor 302 and the pump piston 304.

[0053] Figure 8A shows an assembled view, Figure 8B shows a detailed view, and Figure 8C shows a cross-sectional view of the patch pump during a valve state change after an intake stroke. Torque is transmitted from the drive shaft of the motor 302 to the pump piston 304, then through the coupling pin 310 to the pump housing 308. Once the coupling pin 310 rotates to the end of the helical groove 334, further rotation of the motor 302 causes the coupling pin 310 to rotate the pump housing 308 and pump piston 304 as a unit without relative axial translation. A side port 330 on the pump housing 308 rotates between the reservoir port 326 and the cannula port 328. Surface tension in the side port 330 of the pump housing 308 retains fluid within the pump volume 320. Over the next 180° of rotation of the motor 302, the pump housing side port 330 transitions out of alignment with the reservoir port 326 and into alignment with the cannula port 328. During this time, both the cannula port 328 and the reservoir port 326 are closed. The coupling pin 310 is at the end of the helical groove 334 and transmits torque to the pump housing 308. The coupling pin 310 locks the pump piston 304 and the pump housing 308 together, preventing relative axial movement between the two components. Therefore, the pump piston 304 and the pump housing 308 rotate as a unit and do not translate relative to each other. The pump housing 308 rotates, the pump volume 320 is fixed, and the pump piston 304 rotates. The seal 314, seal carriage, and valve housing 318 are preferably stationary.

[0054] Figure 9A is an assembly view, and Figure 9B is a cross-sectional view of the metering subsystem in the inspiratory transition stop position, ready to infuse. As shown, the side port 330 of the pump housing 308 is aligned with the cannula port 328, the pump volume 320 is enlarged, and the reservoir port 326 is closed. The rotation limit sensor 332 is engaged by a mechanism on the rotating pump housing 308. The motor 302, pump piston 304, and pump housing 308 are stationary.

[0055] 10A is an assembly view and FIG. 10B is a cross-sectional view of the metering subsystem 300 during the exhaust stroke. At the end of the intake stroke, the pump housing 308 rotate limit Sensor 332, thereby switching the direction of the DC motor 302. The motor 302 therefore rotates the piston 304, driving the coupling pin 310 down the helical groove 334 in the pump housing 308 and axially translating the piston 304. The pump piston 304 translates axially away from the DC motor 302, increasing the pump volume 320. and Cannew Report 328 Outside The pump housing 308 is configured to pump fluid from the pump volume 320 into the cannula. During the ejection stroke, friction between the seal 314 and the outer diameter of the pump housing 308 is preferably high enough to ensure that the pump housing 308 does not rotate. The cannula port 328 is open to fluid flowing out of the collapsed pump volume 320. The reservoir port 326 is closed. The pump housing 308 is stationary while the pump volume 320 is collapsed, and the pump piston 304 rotates and translates in a helical motion. A motor is slidably connected to the piston 304 and corresponds to the translational movement of the piston as it rotates within the helical groove 334.

[0056] Figure 11A shows an assembly view, Figure 11B shows a detailed view, and Figure 11C shows a cross-sectional view of the metering subsystem 300 during a valve state change after the discharge stroke. Torque is transmitted from the drive shaft of the motor 302 to the pump piston 304, then through the coupling pin 310 to the pump housing 308. The pump housing 308 and pump piston 304 rotate as a unit with no relative axial motion. A side port 330 on the pump housing 308 rotates between the reservoir port 326 and the cannula port 328, both of which are closed during rotation. Surface tension in the side port 330 of the pump housing 308 retains fluid within the pump volume 320. The coupling pin 310 locks the pump piston 304 and pump housing 308 together, preventing relative axial motion between the two components. Therefore, the pump piston 304 and pump housing 308 rotate as a unit with no relative translation. The pump housing 308 rotates while the pump volume 320 is fixed. The seal 314, seal carriage, and valve housing 318 are preferably stationary.

[0057] Figure 12A is an assembly view, and Figure 12B is a cross-sectional view of the metering subsystem 300 after a pump cycle has been completed. The pump mechanism (piston 304) is fully extended, completing the pump cycle. The rotation limit sensor 332 is engaged to reverse the motor 302 and begin the pump cycle again. The cannula port 328 is closed, while the reservoir port 326 is open to fluid flow from the reservoir.

[0058] In the exemplary embodiment described above, the pump piston both rotates and translates, the pump housing rotates, and the valve housing is stationary. However, it should be understood that in other embodiments, the system may be configured such that the pump piston rotates, the pump housing both rotates and translates, the valve housing translates, or any other combination of motions that increase and decrease the pump volume, and the port in communication with the pump volume transitions from alignment with the reservoir port to alignment with the cannula port.

[0059] In the exemplary embodiment described above, the pump stroke and valve state change consist of a 180° rotational actuation from the motor, however, it should be understood that any suitable angle may be selected for the pump cycle segments.

[0060] In the exemplary embodiment described above, there is an atmospheric seal between the cannula port and the reservoir port during a valve state change. However, it should be understood that in other embodiments, seals may be configured or additional seals may be added to eliminate an atmospheric seal and seal the pump and valve system during a state change.

[0061] In the exemplary embodiment described above, DC gear motors are used to drive the pumps and valves. However, in other embodiments, any suitable drive mechanism may be provided to drive the pumps and valves. For example, solenoids, nitinol wire, voice coil actuators, piezo motors, wax motors, and / or any other type of motor known in the art may be used to drive the pumps.

[0062] In the exemplary embodiment described above, the pump uses a full ejection stroke, however, it should be understood that in other embodiments, a system with incremental ejection strokes may be used to administer finer doses.

[0063] In the exemplary embodiment described above, the pump uses on / off limit switches to determine the state of the system at the limits of rotational travel. However, it should be understood that in other embodiments, other sensors with the ability to determine intermediate states, such as encoder wheels or optical sensors, may be used to improve the resolution of the sensing scheme.

[0064] It will be appreciated that the internal diameter of the pump can be adjusted to vary the nominal power output per cycle.

[0065] In the exemplary embodiment described above, the pump uses elastomeric O-ring seals. However, it should be understood that other arrangements may be used. For example, the fluid seal may be molded directly onto the seal carriage, other elastomeric seals such as quad rings may be used, or other sealing materials such as Teflon or polyethylene lip seals may be used.

[0066] In an alternative embodiment of the present invention, the movement of the pump can be used to trigger or actuate the deployment of the cannula.

[0067] In the illustrative example described above, the system advantageously uses bidirectional actuation. The motor's rotation is counter-rotated to alternate intake and exhaust strokes. This provides a safety mechanism to prevent runaway in the unlikely event of a motor malfunction. The motor must reciprocate in a sequential manner in order for the pump to continue to deliver drug from the reservoir. However, it should be understood that in other embodiments, the metering system is designed to use a unidirectional actuator.

[0068] In the exemplary embodiment described above, the system uses a pouch reservoir with two flexible walls, however, in other embodiments, the reservoir can be formed in any suitable manner, including with one rigid wall and one flexible wall.

[0069] 13 is an exploded perspective view of a metering subsystem 1300 for a patch pump in accordance with another exemplary embodiment of the present invention. The metering subsystem 1300 includes a motor and gearbox assembly 1302 and a pump assembly 1304.

[0070] 14 is an exploded perspective view of a pump assembly 1304. The pump assembly 1304 includes a piston 1306 mechanically coupled to a sleeve 1308 via a coupling pin 1310 within a pump manifold 1312. The pump assembly 1304 further includes a port seal 1314, a plug 1316, a sleeve rotation limit switch 1318, and an output gear rotation limit switch 1320.

[0071] The piston 1306 can rotate a total of 196° in either direction and translate approximately 0.038 inches. The sleeve 1308 and plug 1316 rotate together (as a pair) 56° in either direction. The pump manifold 1312 and port seal 1314 are stationary.

[0072] 15 is an exploded perspective view of the motor and gearbox assembly 1302. The motor and gearbox assembly 1302 includes a gearbox cover 1322, a compound gear 1324, an output gear 1326, a shaft 1328, a gearbox base 1330, a motor pinion gear 1332, and a DC motor 1334.

[0073] 16A-16D illustrate the assembly and operation of the piston 1306, sleeve 1308, and coupling pin 1310. FIG. 16A illustrates the piston 1306 including a press-fit bore 1338 that receives the coupling pin 1310 and a piston seal 1340 that fluid-tightly seals the piston within the sleeve 1308. The sleeve 1308 includes a helical groove 1342. The piston 1306 is press-fit axially into the sleeve 1308, after which the coupling pin 1310 is press-fit into the bore 1338 through 1342. This implementation achieves similar operation to the previously described embodiment, with rotation of the piston 1306 causing axial translation of the piston 1306 relative to the sleeve 1308 due to the interaction of the coupling pin 1310 with the helical groove 1342. Figure 16B illustrates the assembled piston 1306, sleeve 1308, and coupling pin 1310, together with the coupling pin 1310 shown at the lower end of the spiral groove 1342. Figure 16C illustrates the axial stroke length 1344 of the piston 1306 relative to the sleeve 1308 as a result of the spiral groove 1342. Figure 16D illustrates a tapered surface 1346 that is preferably provided at the end of the spiral groove 1342 to center the coupling pin 1310 within the groove 1342.

[0074] 17A illustrates the assembly of plug 1316 and sleeve 1308. As shown, plug 1316 is secured to key 134. 7 , and a seal 1348. The seal 1348 provides an interference fit for the plug within the sleeve 1308. The sleeve 1308 is secured to the key 134 7 The key 134 is provided with a recess 1350 adapted to receive the key 134. 7The plug 1316 locks the plug 1316 in rotational engagement with the sleeve 1308. The plug 1316 is pressed against the end face of the (advanced) piston 1306 during assembly to minimize air in the pump chamber. Friction between the seal 1348 and the inner surface of the sleeve 1308 holds the plug 1316 axially. With appropriate selection of seal diameter, squeeze, and material, the plug 1316 can also function as an occlusion or overpressure sensor. Pump pressures greater than a threshold value cause the plug 1316 to transition axially and disengage the sleeve rotation limit switch 1318. Friction holds the plug 1316 in place for pressures below a desired threshold. Figures 17B and 17C illustrate the axial movement of the piston 1306 within the sleeve 1308. Figure 17B illustrates the piston 1306 in a first state, where there is minimal or no pumping volume between the piston 1306 and the plug 1316. As shown, the coupling pin 1310 abuts against the bottom end of the spiral groove 1342. Figure 17C illustrates the piston 1306 in a second state with a maximum pump volume 1352 between the piston 1306 and the plug 1316. As shown, the coupling pin 1310 abuts against the top end of the spiral groove 1342.

[0075] Figures 18A-18D illustrate the assembly of sleeve 1308 to manifold 1312. As shown in Figure 18A, manifold 1312 includes port seals 1314 to seal reservoir port 1354 and cannula port 1356, respectively. Small side holes 1358 (see Figure 17B) on the sleeve rotate back and forth between the two ports, which are 56° apart. As shown in Figure 18B, sleeve 1308 includes tabs 1360, and manifold 1312 includes corresponding slots 1362 to allow sleeve 1308 to be assembled to manifold 1312. Figure 18C illustrates manifold windows 1364 provided in the manifold. Tabs 1360 are received and transition into windows 1364 when sleeve 1308 is assembled to manifold 1312. Tab 1360 and window 1364 interact to allow sleeve 1308 to rotate between two positions while restraining axial translation of sleeve 1308 relative to manifold 1312. Sleeve 1308 rotates between a first position in which side hole 1358 is aligned with reservoir port 1354 and a second position in which side hole 1358 is aligned with cannula port 1356. Figure 18D illustrates sleeve 1308 assembled to manifold 1312 with tab 1360 positioned within manifold window 1364.

[0076] 19 is a cross-sectional view of the assembled metering system. As shown, the port seal 1314 is a face seal that is compressed between the OD (outer diameter) of the sleeve 1308 and a recessed pocket in the manifold 1312. Also shown is a tab 1360 located in the manifold window 1364, and a side hole 1358 is shown transitioning between the reservoir port 1354 and the cannula port 1356. The output gear 1326 includes a cam mechanism 1366 that engages the rotation limit switch 1320 to signal the end of rotational movement of the piston 1306 and sleeve 1308 in either direction.

[0077] 20A-20E are cross-sectional views illustrating the rotation of the sleeve 1308 within the manifold 1312 to transition the side hole from alignment with the reservoir port 1354 to alignment with the cannula port 1356. FIG. 20A illustrates the side hole 1358 aligned with the reservoir port 1354. While in this position, the piston 1306 transitions away from the plug 1316, filling the volume 1352 with fluid from the reservoir. FIG. 20B illustrates the sleeve 1308 as it begins to rotate toward the cannula port 1356. In this position, the side hole 1358 is sealed by the seal 1314 on the reservoir port 1354. For this reason, the diameters of the seal 1314 and side hole 1358 are preferably selected so that the seal 1314 covers the opening of the side hole 1358. Figure 20C illustrates the side hole 1358 in the sleeve 1308 between the seal 1314 of the reservoir port 1354 and the seal 1314 of the cannula port 1356. In this position, neither seal 1314 closes the side hole 1358, but the surface tension of the liquid retains the liquid within the pump chamber. Figure 20D illustrates the side hole 1358 rotated further to a position where the seal 1314 of the cannula port 1356 covers the opening of the side hole 1358. Finally, Figure 20E illustrates the side hole 1358 rotated into alignment with the cannula port 1356. While in this position, the piston 1306 translates axially, reducing the volume 1352 and forcing fluid out of the cannula port 1356 and into the cannula.

[0078] FIGS. 21A-21C illustrate the operation of the limit switch. As shown in FIG. 21A, the plug 1316 includes a cam mechanism 1368 that interacts with the limit switch 1318. As the sleeve 1308 and plug 1316 rotate, the cam mechanism 1368 forces a metal bend in the limit switch 1318 into contact with one another until the plug 1316 has fully rotated to the next position. When the plug 1316 is at either end of its rotation, a ridge 1370 on one of the bends rests within the cam mechanism 1368, as shown in FIG. 21C. The limit switch 1318 opens and closes with each rotation cycle, signaling that the plug 1316 remains properly aligned with the limit switch 1318. In an overpressure or occlusion condition, increased pressure causes the plug 1316 to slide out of the sleeve 1308 and out of alignment with the limit switch 1318. In this manner, an overpressure condition is detected. The limit switch 1320 is engaged by a cam mechanism 1366 on the output gear 1326 at each end of the rotational cycle. This sends a signal to reverse the motor 1334. Using two metal flexures as shown, it is not possible to determine from the limit switch which rotational cycle has been completed. However, as will be appreciated, a third flexure allows the direction of engagement to be determined.

[0079] 22A-22C illustrate the assembly of the motor and gearbox 1302 and the pump assembly 1304. As shown in FIGS. 22A and 22B, the motor and gearbox 1302 includes an opening 1372 for receiving the rotational limit switch 1320. In this manner, the output gear 1326 inside the gearbox housing can access and engage the bends of the limit switch 1320. The motor and gearbox 1302 also includes an axial retention snap 1374 so that the pump assembly 1304 can be snap-fitted onto the motor and gearbox 1302. The motor and gearbox 1302 includes a rotation key 1376 within a pump receiving socket 1378 to receive the pump assembly 1304 and constrain rotation of the pump assembly 1304 relative to the motor and gearbox 1302. The output gear 1326 includes a slot 1380 (FIG. 22B) adapted to receive a tab 1382 (FIG. 22C) provided on the piston 1306. When assembled, tabs 1382 are received in slots 1380, allowing output gear 1326 to transmit torque to piston 1306. As output gear 1326 rotates, pump piston tabs 1382 rotate and slide axially within the slots. Metal spring flexures on the motor connections and limit switches are used to make electrical contact with pads on the circuit board during final assembly.

[0080] In operation, the pump cycle for the embodiment described above involves five steps: approximately 120° of pump discharge (counterclockwise when looking from the pump toward the gearbox), 56° of valve state change (counterclockwise), 140° of pump intake (clockwise), 56° of valve state change (clockwise), and approximately 20° of jog (counterclockwise) to clear the limit switch. The complete pump cycle requires 196° of output gear rotation in each direction.

[0081] 23A-30C illustrate the pump cycle. For clarity, only the output gear 1326 of the gearbox assembly 1302 is shown.

[0082] Figure 23A illustrates the start position. As shown, the cam 1366 of the output gear 1326 is not in contact with the rotation limit switch 1320 and the flexures are not touching each other. The pump piston 1306 is retracted, as shown by the position of the coupling pin 1310 in the helical groove 1342 in Figure 22C. In this position, the sleeve 1308 closes the reservoir flow path, the cannula port 1356 is open to the side hole 1358 in the sleeve 1308, and both the rotation limit sensor 1320 and the sleeve sensor 1318 (see Figure 23B) are open.

[0083] Figures 24A and 24B illustrate the metering subsystem during the exhaust stroke. The output gear 1326 rotates the pump piston 1306 in a first rotational direction (see arrow in Figure 24B), which is driven via the coupling pin 1310 (see Figure 24A) along the helical path of the spiral groove 1342 in the sleeve 1308. As the pump piston 1306 rotates, it translates away from the gearbox, expelling fluid from the pump chamber 1352 and out of the cannula port 1356. During the exhaust stroke, friction between the port seal 1314 and the outer diameter of the sleeve 1308 should be high enough to ensure that the sleeve 1308 does not rotate during this part of the cycle.

[0084] Figures 25A-25C illustrate the metering subsystem during a valve state change after the discharge stroke. As shown in Figure 25A, after the coupling pin 1310 reaches the distal end of the helical groove 1342, torque continues to be transmitted from the output gear 1326 to the pump piston 1306, through the coupling pin 1310, and to the sleeve 1308. The sleeve 1308 and pump piston 1306 rotate as a unit with no relative axial motion. A side hole 1358 (not shown in Figures 25A-25C) on the sleeve 1308 transitions between the reservoir port 1354 and the cannula port 1356. A tab 1360 transitions within a window 1364 in the manifold 1312 in the direction indicated by the arrow. As shown in Figure 25B, the sleeve limit switch 1318 is closed by the cam surface of the plug 1316.

[0085] Figures 26A and 26B show the metering subsystem in the discharge rotation stop position. The sleeve side hole 1358 (not shown in Figures 26A or 26B) is aligned with the reservoir port 1354, the pump volume 1352 is collapsed, and the cannula port 1356 is closed. The plug 1316 is in the stop position and the sleeve limit switch 1318 is open. The output gear cam 1366 contacts the rotation limit switch 1320 to signal the end of rotation, stopping the output gear 1326 from reverse rotation.

[0086] 27A and 27B show the metering subsystem during the intake stroke. The output gear 1326 rotates the pump piston 1306 in the direction shown by the arrow in FIG. 27B. The piston 1306 rotates along the spiral groove 13 42 Due to the interaction of the coupling pin 1310 within the manifold 1312, the pump piston 1306 translates axially relative to the sleeve 1308. The pump piston 1306 translates towards the gearbox, drawing fluid from the reservoir into the pump chamber 1352. During the intake stroke, the friction between the seal and the outer diameter of the sleeve 1308 should be high enough to ensure that the sleeve 1308 does not rotate relative to the manifold 1312.

[0087] 28A-28C show the metering subsystem during the valve state change after the intake stroke. The coupling pin 1310 reaches the top end of the spiral groove 1342 and the motor 13 34 continues to supply torque, causing the sleeve 1308 and piston 1306 to rotate together. A tab 1360 on the sleeve 1308 transitions within a window 1364 in the manifold 1312 in the direction shown by the arrow in FIG. 28A . A cam surface 1368 on the plug 1316 closes the sleeve limit switch 1318 as the plug 1316 rotates with the sleeve 1308. The sleeve 1308 and pump piston 1306 rotate as a unit with no relative axial motion. During this rotation, the side hole 1358 in the sleeve 1308 transitions between the reservoir port 1354 and the cannula port 1356.

[0088] 29A and 29B show the metering subsystem in the intake rotation stop position. In this position, the side hole 1358 of the sleeve 1308 aligns with the cannula port 1356, the pump volume 1352 is enlarged, and the reservoir port 1354 is closed. The cam 1366 of the output gear 1326 engages the rotation limit switch 1320, signaling that rotation is complete. 34 prevents reverse rotation. Sleeve limit switch 1318 is open.

[0089] 30A-30C show the metering subsystem after a pump cycle is completed, with the output gear cam 1366 swinging away from the rotary switch 1320, ready to begin another cycle.

[0090] Figures 31A-31C illustrate another metering system 3100a in accordance with an exemplary embodiment of the present invention. Figure 31A shows a motor and gearbox assembly 3101 and an improved pump assembly 3100. The motor and gearbox assembly 3101 is substantially similar to the motor and gearbox assembly shown and described above in connection with Figures 13-30C.

[0091] 32 is an exploded perspective view of a pump assembly 3100. The pump assembly 3100 includes a pump manifold 3102, a port seal 3104, a seal retainer 3106, a piston 3108 that rotates ±196° and translates axially ±0.038 inches, a coupling pin 3110, a sleeve 3112 with conductive pads, and a sleeve rotation limit switch 3114 with a bent arm 3128. The sleeve 3112 with conductive pads rotates ±56° as shown.

[0092] The pump assembly 3100 includes three flexure arms 3128 that operate as rotational translation limit switches 3114. The rotational translation limit switches 3114 will be described in further detail below. The rotational translation limit switches 3114 directly sense the position of the sleeve 3112 rather than sensing the position of the output gear. This allows for more precise angular alignment of the sleeve 3112 relative to the manifold 3102 and cannula ports.

[0093] 33A-33B illustrate the assembly of the piston 3108 into the sleeve 3112. In this embodiment, the inner wall 3113 within the sleeve 3112 forms the end face of the pump chamber. Features on the piston sleeve are designed to allow for minimal clearance between the end face of the piston 3108 and the surface of the inner wall 3113 of the sleeve.

[0094] 34A-34E show the sleeve 3102 attached to the manifold 3102. 1234D illustrates the assembly of the port seal 3104, seal retainer 3106, and sleeve 3112. As shown, the port seal 3104, seal retainer 3106, and sleeve 3112 are inserted into the manifold 3102. Small side holes 3115 (see FIG. 34E) on the sleeve 3112 rotate back and forth between the reservoir port and the cannula port, which are preferably 56° apart. The sleeve 3112 is inserted past retention tabs 3116 (see FIG. 34D) in the manifold 3102 and then rotated into place to inhibit axial translation. Because this embodiment inhibits or minimizes axial movement of the plug, occlusion detection due to axial movement of the plug is generally not provided.

[0095] 35 illustrates a cross section of the sleeve 3112 and manifold 3102 assembly taken through the port seal 3104 and through the axis of the side port to the manifold 3102. The side port to the manifold 3102 includes a cannula port 3118 and a reservoir port 3120. The port seal 3104 is a face seal and is compressed between the outer diameter of the sleeve 3112 and a recessed pocket in the manifold 3102.

[0096] 36A-36C are cross-sectional views through the axis of the side port to illustrate the valve state change as the sleeve 3112 rotates from the reservoir port 3120 to the cannula port 3118. In the initial position shown in FIG. 36A, the sleeve side hole 3115 is open to the reservoir port 3120. In this position, the cannula port 3118 is closed. In the intermediate position shown in FIG. 36B, the sleeve side hole 3115 is closed by the port seal 3104 during the transition. In the final position shown in FIG. 36C, the sleeve side hole 3115 is open to the cannula port 3118. In this position, the reservoir port 3120 is closed.

[0097] Figures 37A-37D illustrate the operation for the sleeve rotation limit switch 3114. The three-contact switch design allows the patch system to distinguish between two rotation limits via a switch input signal rather than tracking the sleeve's angular orientation via software. The manifold 3102 preferably includes manifold mounting posts 3122. The switch contacts 3114 are bonded to the posts 3122 using adhesive, ultrasonic welding, heat staking, or any other suitable bonding method. The sleeve 3112 includes conductive pads 3124 at the ends of the sleeve 3112. These may be printed or overmolded metal inserts, or may be provided by any other suitable means. The sleeve rotation limit switch 3114 includes a plastic overmold 3126 for spacing and mounting mechanisms for the flexures. The sleeve rotation limit switch 3114 also includes three metal flexures 3128. The manifold 3102 is provided with alignment slots 3130 that receive the flexures 3128. In a first position, shown in FIG. 37B, the side hole 3115 on the sleeve 3112 is aligned with the cannula port 3118. In this position, the conductive pad 3124 on the sleeve 3112 bridges the center and right contacts 3128a, 3128b. In an intermediate position, shown in FIG. 37C, the side hole 3115 on the sleeve 3112 is halfway between the ports 3118 and 3120. In this position, both sides of the switch 3114 are open. In a final position, shown in FIG. 37D, the side hole 3115 on the sleeve 3112 is aligned with the reservoir port 3120. In this position, the conductive pad 3124 on the sleeve 3112 bridges the center and left contacts 3128b, 3128c.

[0098] The pump described above has an improved operating sequence. The operating sequence is essentially the same as described above, except that the 20° back-jog is no longer required. The back-jog is not required with the three-point contact switch design described above, and the complete pump cycle consists of four segments: first, there is a pump discharge of approximately 140°, which is counterclockwise when looking from the pump toward the gearbox; second, there is a 56° valve state change, also counterclockwise; third, there is a 140° pump intake, which is clockwise; and fourth, there is a 56° valve state change, also clockwise. This total pump cycle requires 196° of output gear rotation in each direction.

[0099] 38A and 38B illustrate exploded views of another version of the pump assembly in which the elastomeric port and piston seals are overmolded onto the manifold and pump piston, respectively. This version of the pump functions in substantially the same manner as described above, but has fewer separate components and is easier to assemble. Overmolding the seals directly onto the manifold and piston reduces the number of dimensions that contribute to seal compression, allowing for less variability and tighter control of sealing performance.

[0100] FIG. 39A illustrates an exploded view of a pump assembly 3900 with an alternative rotation limit switch design. This version of the pump assembly includes a two-point contact design for the sleeve rotation limit switch. With this design, the pump will rock back appropriately at the end of the pump cycle so that the contact switch 3902 is seated and open. In the first position, as shown in FIG. 39B, the side hole 3115 on the sleeve is aligned with the cannula port. In this position, the first rib 3904 on the sleeve forces the contraction closed. In the intermediate position, shown in FIG. 39C, the side hole 3115 on the sleeve is halfway between the ports and is open because neither rib 3904, 3906 touches the contact switch 3902. In the third position, shown in FIG. 39D, the side hole 3115 on the sleeve is aligned with the reservoir port. In this position, the second rib 3906 on the sleeve again forces the contact switch 3902 closed.

[0101] FIG. 40 is an exploded perspective view of another exemplary embodiment of a metering assembly 4000. This embodiment is substantially similar to the above-described embodiment, and the following description will focus on the differences. The metering assembly 4000 includes a sleeve 4002 having a spiral groove 4004, a plug 4006, a seal 4008, a plunger 4010, a coupling pin 4012, a manifold 4014, a port seal 4016, and a flexible interlock 4018. FIG. 41 illustrates the metering assembly in its packaging. The seal 4008 is preferably formed of an elastomeric material and is one-piece in construction. One seal 4008 is attached to the plug 4006, and the other seal 4008 is attached to the plunger 4010. The plug 4006 is preferably secured to the sleeve 4002 by adhesive, heat sealing, or any other suitable means. An end face of the plug forms one side of the pump volume. The plunger 4010 is inserted into the sleeve 4002, and the coupling pin 4012 is press fit onto the plunger 4010 and extends into the helical groove 4004 to provide axial translation of the plunger 4010 when rotated by a motor (not shown). The end face of the plunger 4010 forms the opposing surface of the pump volume. The port seal 4016 is preferably a single molded piece of elastomeric material. This embodiment reduces part count and improves manufacturability. Figure 42 is a cross-sectional view of the assembled metering assembly.

[0102] 43A-43C illustrate the interaction of the interlock 4018 and the sleeve 4002. As shown in FIG. 41, the interlock 4018 is attached to the manifold 4014 at either end of the interlock 4018. As shown in FIG. 43A, the end face of the sleeve 4002 includes a detent 4020 that abuts a ridge 4022 on the interlock 4018 when the metering assembly is in the first position (side hole aligned with the reservoir pump). Under certain conditions, such as back pressure, the piston 4010 and sleeve 4002 may move together. 2The friction between the plunger 4010 and the coupling pin 4012 could be sufficient to rotate the sleeve before the plunger 4010 and the coupling pin 4012 reached either end of the spiral groove 4004, which could result in an incomplete volume of liquid being pumped per stroke. To prevent this situation, the interlock 4018 prevents the sleeve 4002 from rotating until the torque passes a predetermined threshold. This prevents the piston 4010 from rotating the sleeve 4002 until the coupling pin 4012 reaches the end of the spiral groove 4004. 2 Once the coupling pin hits the end of the spiral groove 4004, further movement by the motor increases the torque on the sleeve above a threshold, deflecting the interlock and allowing the detent 4020 to pass by the ridge 4022. This is shown in FIG. 43B. 2 Upon completion of the rotation, when the side hole is oriented with the cannula port, the detent 4020 transitions over the ridge 4022 in the interlock 4018. This is shown in Figure 43C.

[0103] 44 illustrates a cross section of another exemplary embodiment of a metering system 4400. The metering system 4400 includes a modified sleeve 4402 having a surface 4404 that forms one side of the pump volume. This embodiment eliminates the need for a plug as in the previous embodiment, simplifying manufacturing.

[0104] FIG. 45 illustrates another exemplary embodiment having a modified sleeve 4500 and switching mechanism 4502. FIG. 46 is a perspective view of the modified sleeve 4500, including a detent 4504 similar to the sleeves described above for interacting with an interlock (not shown). The switch mechanism 4502 includes a limit switch arm 4506 adapted to rotate in either direction away from its neutral position. The sleeve 4500 includes a switching lever (actuator arm) 4508 adapted to interact with the limit switch 4506 as the sleeve 4500 rotates. FIG. 47 illustrates how the limit switch 4506 rotates about an axis. The switch mechanism 4502 provides an electrical signal to indicate the position of the limit switch 4506. FIG. 48 is a top view showing the sleeve 4500 rotated from its neutral position to an orientation in which the limit switch 4506 has rotated its maximum angle (α). Further rotation of the sleeve causes the limit switch 4506 to break free from 4508 and return to its neutral position. This change in switch arm orientation signals the end of rotation of the sleeve 4500 in one direction and reverses the rotation of the rotary metering pump. FIG. 49 is a side view facing the sleeve, illustrating the same interaction between the limit switch 4506 and the actuator arm 4508. FIG. 50 is a side view showing the sleeve 4500 and switching mechanism 4502 incorporated into a patch pump with an interlock collar 4510.

[0105] FIG. 51A shows the relative angular position of the limit switch 4506 and the actuator arm 4508. Alpha (α) is the angle of the limit switch 4506. Beta (β) is the angle between the rotating sleeve and the actuator arm. Ta The angle of the arm. Figure 51B shows the relative change d(α) / d(β) vs. β. Converse rotation is preferably initiated at β=33°. As shown, the actuator Ta Arm 4 5 As the actuator 4508 rotates, it pushes the limit switch 4506 away from the neutral position (α=0°). TaWhen the arm angle β reaches about 30°, the actuator Ta The arm 4508 clears the limit switch 4506, which returns to neutral (α=0°), thereby initiating reverse rotation of the rotary pump. 0 When the is rotated in the other direction, the same procedure occurs in reverse, thus causing the sleeve to reciprocate back and forth.

[0106] The improved plunger and pump plug components will now be described in connection with FIGS. 52-67. As will be described, the improved plunger 5210 and pump bottom 5206 improve the pump by making these components easier to manufacture and assemble and by eliminating a potential source of fluid leakage from previous designs. The plunger 5210 is illustrated in multiple views in FIGS. 52-58. The plunger 5210 is substantially similar to the plunger 4010 illustrated in FIG. 40, except that the O-ring 4008 is not required because a seal, described below, is overmolded onto the head 5212 of the plunger 5210.

[0107] The seal 5214 is shown in multiple views in Figures 59-62. The seal 5214 is advantageously overmolded onto the head 5212 of the plunger 5210. Thus, the sealed plunger is advantageously manufactured in a two-shot molding process. The plunger 5210 is molded from a hard plastic material, and then the seal 5214 is molded onto the plunger 5210 as a second shot from a viscoelastic elastomer. The plunger 5210 and seal 5214 combination is easier to assemble into the overall pump and can reduce the chance of leakage presented by O-ring designs.

[0108] A pump stopper or plug 5206 is shown in FIGS. 63-67. The stopper 5206 substantially corresponds to the plug 4006 of FIG. 40, except that a seal 5214 (the same or substantially similar sealing component may be used for both the plunger 5210 and the stopper 5206) is overmolded onto the head 5208 of the stopper 5206 instead of an O-ring. As with the plunger 5210 described above, the stopper 5206 and seal 5214 are preferably manufactured in a two-shot molding process. The stopper 5206 is molded from a hard plastic material, and the seal 5214 is molded onto the stopper 5206 in a second shot from a viscoelastic elastomer.

[0109] 68 illustrates an exploded view of the metering assembly 4000, but with the modified plunger 5210, stopper 5206, and seal 5214. Those skilled in the art will appreciate that just as the plug 4006 was optional in prior designs and could be replaced with a wall 4404 as shown in FIG. 44, the stopper 5206 is also optional and could be replaced with a similar wall.

[0110] A method 6900 of manufacturing and assembling a pump according to an exemplary embodiment of the invention utilizing the above-described overmolded parts will now be described with reference to FIG. 69. First, in step 6902, a plunger is molded from hard plastic. Next, in step 6904, a seal is overmolded onto the head of the plunger. The seal is molded from a viscoelastic elastomer and is sized to fit and seal within the pump chamber. Optionally, in step 6906, a pump stopper is molded from hard plastic, and in step 6908, the seal is overmolded onto the head of the pump stopper. In step 6910, the plunger and pump stopper are inserted into the pump chamber of the pump. In step 6912, a pin is inserted into a hole in the plunger to allow axial translation of the plunger as the pump motor rotates the pump chamber.

[0111] A further embodiment of the present invention is illustrated in Figures 70A-70L. To function as intended, the sleeve and plunger must operate in the correct sequence. That is, because the output gear is coupled to the plunger, the output gear is intended to first rotate the plunger, and the coupling pin moves within the helical slot in the sleeve, thereby advancing or retracting the plunger. Then, once the coupling pin reaches the end of the slot (either end, depending on the direction of rotation), further rotation causes the plunger and sleeve to rotate together, changing the orientation of the sleeve relative to the manifold. However, as noted above, in practice, friction or other forces can disrupt the sequence of operation. If the force between the plunger and sleeve is too great and unmitigated, the plunger and sleeve may initially rotate together before the plunger moves relative to the sleeve. Figures 40-43C illustrate a flexible interlock that initially resists rotation of the sleeve until the plunger is fully advanced or retracted. 70A-70L illustrate an alternative embodiment of the pumps described herein in which a reciprocating shuttle may be included within the pump mechanism in place of a flexible interlock. The reciprocating shuttle does not rely on the flexibility or other characteristics of the interlock portion, advantageously improving reliability and providing deterministic sequencing of the pump mechanism. An exemplary reciprocating shuttle will now be described.

[0112] 70A-70L schematically illustrate a sleeve 7001, an output gear 7002, a coupling pin 7003, a helical slot 7004, and a reciprocating shuttle 7005. For purposes of illustrating the movement of the shuttle, a "bullseye" or "dot" on the shuttle 7005 indicates movement out of the plane of the drawing along an axis extending perpendicular to the plane of the drawing, and a "cross" or "x" on the shuttle indicates movement into the plane of the drawing. As discussed above, it will be understood that movement of the coupling pin 7003 within the helical slot 7004 corresponds to axial movement of the plunger within the sleeve, increasing or decreasing the volume of the pump chamber.

[0113] In the illustrated embodiment, when shuttle 7005 retracts into the plane of the drawing, it does not impede rotation of sleeve 7001. And when shuttle 7005 advances out of the plane of the drawing, shuttle 7005 prevents rotation of sleeve 7001 by obstructing movement of detent 7006. 0 C, 7 0 D, 7 0 I and 7 0 J illustrates a portion of the sequence in which the shuttle 7005 interferes with the rotation of the sleeve 7001. However, the forward / retract positions can be reversed if desired, and the embodiment can still function as intended, as long as the shuttle blocks or allows the sleeve to rotate at the appropriate moments in the pumping sequence.

[0114] Next, the pumping sequence involving movement of shuttle 7005 will be described in detail. Figure 70A illustrates the initial position in the pumping sequence. For example, sleeve 7001 is in a first position with the input port aligned with the reservoir port of the manifold. The plunger and pin 7003 are in their initial positions, with the pump reservoir in an empty configuration. The output gear 7002 is in its initial position ready to begin the first portion of its reciprocating rotation. Shuttle 7005 is fully retracted into the drawing and is not obstructing the movement of detent 7006.

[0115] FIG. 70B illustrates the beginning of rotation of the output gear 7002. Preferably, during this portion, the coupling pin 7003 moves within the slot 7004, retracting the plunger and increasing the volume of the pump chamber. However, the sleeve 7001 will tend to rotate with the output gear due to friction or other forces. Through the interaction of a cam or other similar structure, which will be described later, at this stage in the sequence, the shuttle 7005 begins to advance in a direction out of the plane of the drawing. As shown in FIG. 70C, due to the cam or other interaction between the output gear within the shuttle, the shuttle is fully advanced and prevents further rotation of the detent 7006 while allowing the output gear and coupling pin 7003 to rotate. As a result, the output gear and coupling pin rotate until the coupling pin reaches the end of the helical slot 7004. Meanwhile, the sleeve 7001 and its detent 7006 remain stationary, as shown in FIG. 70D. As shown in FIG. 70E, at this stage, the cam (or another suitable interaction between the output gear and shuttle) causes the shuttle 7005 to retract into the plane of the drawing. As a result, the sleeve 7001 and detent 7006 can rotate. FIG. 70F illustrates how the output gear 7002, coupling pin 7003, and sleeve 7001 all rotate together, moving the sleeve and orienting its port from an input position to an output position relative to the manifold. FIG. 70G illustrates the pump mechanism at the end of the first half of its reciprocating motion. The sleeve 7001 has fully rotated to its output position relative to the manifold, while the shuttle 7005 remains retracted.

[0116] Figure 70H illustrates the start of reciprocation back toward the initial position. The output gear 7002, coupling pin 7003, and possibly sleeve 7001 begin to rotate counterclockwise. Due to cam interaction (or another suitable interaction between the output gear and shuttle), the shuttle 7005 again begins to advance out of the plane of the drawing. Figure 701 illustrates a portion of the sequence in which the shuttle 7005 again fully advances, preventing rotation of the sleeve 7001 while the output gear 7002 and coupling pin 7003 rotate counterclockwise. Figure 70J illustrates a portion of the sequence once the coupling pin 7003 has fully rotated within the helical slot 7004, thereby reducing the size of the pump chamber and expelling fluid through the manifold output port. Figure 70K illustrates that as the output gear 7002 continues to rotate clockwise, the cam (or another suitable interaction between the output gear within the shuttle) retracts the shuttle 7005 into the plane of the drawing. Figure 70L illustrates the shuttle 7005 fully retracted, with the output gear 7002, coupling pin 7003, and sleeve 7001 all rotating together back to the initial position illustrated in Figure 70A. This is the complete pumping sequence, which can be repeated as necessary to deliver medical fluid from the reservoir, through the pumping chamber, and to the output port.

[0117] FIG. 71 illustrates an exploded view of the assembly of the output gear 7002 and shuttle 7005, which reciprocates, advancing and retracting the shuttle in time relative to the rest of the pump assembly. The shuttle 7005 includes a shuttle pin 7009. While the shuttle pin 7009 is illustrated, those skilled in the art will appreciate that any other coupling or interconnection structure would suffice. The output gear 7002 includes a cam structure 7007, which further includes a shuttle cam slot 7008. The shuttle pin 7009 is received within the shuttle cam slot 7008, so that as the output gear 7002 rotates, the shuttle 7005 advances and retracts in the direction indicated by the arrows as the shuttle pin 7009 is forced to move within the shuttle cam slot 7008. FIGS. 72A-72C further illustrate this motion. Note that structure for limiting movement of the shuttle 7005 in directions other than along the arrows shown in FIG. 71 would naturally need to be included, but is not shown here for simplicity. In FIG. 72A , the output gear 7002 is ready to begin rotation in one direction, with the shuttle 7005 in a fully retracted position. The shuttle pin 7009 is at the far end of the shuttle cam slot 7008. As shown in FIG. 72B , the output gear 7002 is midway through its rotation in that direction, with the shuttle 7005 advanced to a fully advanced position due to the interaction of the shuttle pin 7009 with the shuttle cam slot 7008. FIG. 72C illustrates the end of the first rotation of the output gear 7002. At this position, the shuttle 7005 is again fully retracted, with the shuttle pin 7009 at the opposite, far end of the shuttle cam slot 7008. As will be appreciated by those skilled in the art, this example illustrates one example of an exemplary mechanical structure for achieving regular and deterministic advancement and retraction of the shuttle to either prevent or allow sleeve rotation as described above. Any other suitable mechanical arrangements for providing precise timing between the shuttle advancement and retraction and the sleeve rotation are considered within the skill of those skilled in the art.

[0118] Another exemplary embodiment will now be described in connection with FIGS. 73-82. This embodiment simplifies the previous embodiment, particularly by eliminating the need for interlocks to achieve proper sequencing of the piston and rotation of the sleeve assembly, while also improving insulin compatibility by reducing the detrimental effects of shear forces on insulin molecules flowing through the pump as the components slide relative to one another. This embodiment may advantageously reduce hydrophobic surface contact, potentially less than 10% compared to conventional designs. The increased sealing pressure in this embodiment reduces damage to insulin trapped between the sealing surfaces. Optional recesses in the gasket, described in detail below, eliminate significant shear across wetted surfaces, thus further reducing damage to insulin molecules. Portions of the pump that are substantially similar to the previous embodiment will not be repeated here for the sake of brevity and clarity. This embodiment also eliminates the need for a manifold. For example, the interaction of the spiral groove and pin that reciprocates the piston, the interaction of the gearbox and piston assembly, and the limiter switch that reverses the direction of the motor are all substantially unchanged in the following embodiment.

[0119] FIG. 73 illustrates an exploded view of the modified sleeve 7301, gasket 7302, and pump housing 7303 components of this embodiment. In this embodiment, the pump housing includes a cylindrical inner surface 7304 sized to receive a substantially cylindrical gasket 7302. The gasket 7302 is, in turn, assembled onto a gasket-receiving portion 7305 of the modified sleeve 7301. The piston 7306 is shown but is substantially the same as that described above. The gasket 7302 has an opening 7307 that, when assembled, receives an opening 7309 in the sleeve 7301. The gasket 7302 also preferably has a second opening 7308 located opposite the opening 7307. While not strictly necessary, the second opening 7308 improves ease of assembly and also serves to reduce the contact surface area between the gasket 7302 and the inner surface 7304 of the housing 7303.

[0120] Figure 74 illustrates pump assembly 7300 oriented with sleeve opening 7309 aligned with inlet port 7310 of pump housing 7303. Figure 75 is a cross-sectional view of assembly 7300 with sleeve opening 7309 positioned intermediate between an intake state, when sleeve opening 7309 is aligned with inlet port 7310, and an output state, when sleeve opening 7309 is aligned with outlet port 7311. In this intermediate state, gasket 7302 watertight seals sleeve 7301 to housing 7303. Piston seal 7312 operates substantially as previously described.

[0121] Figure 76 illustrates the pump assembly 7300 oriented with the sleeve opening 7309 aligned with the outlet port 7311 of the pump housing 7303. Figure 77 illustrates the pump assembly 7300 oriented so that the sleeve opening 7309 is aligned midway between the inlet port 7310 and the outlet port 7311 of the pump housing 7303.

[0122] FIG. 78 shows the sleeve opening 7309 and gasket opening aligned midway between the inlet port 7310 and the outlet port 7311. 73 79 is a cross-sectional view of the sleeve opening 7309 and gasket opening 7311 aligned with the output port 7311. Also shown is the piston surface 7313. 73 07 is a cross-sectional view illustrating

[0123] FIG. 80 illustrates one embodiment of a gasket 7302. This version includes a gasket opening 7307 and an opposing gasket opening 7308. FIG. 81 illustrates a second embodiment of a gasket with additional indentations 7314 on either side of the openings 7307, 7308. These indentations reduce the contact surface area between the gasket 7302 and the cylindrical inner surface 7304 of the housing 7303. The indentations 7314 therefore reduce friction and reduce degradation of insulin molecules caused by shear when the wetted surface of the gasket 7302 slides against the surface of the housing 7303. FIG. 82 illustrates a gasket 7302 with indentations 7314 on either side of the sleeve opening 7309, as in the pump assembly 7300 oriented so that the sleeve opening 7309 is aligned with the inlet port 7310.

[0124] As will be appreciated, the operation of the pump is substantially similar to that described above. That is, as the motor rotates in a first direction, the sleeve opening 7309 aligns with the inlet port 7310, and the pin and spiral groove increase the volume of the pump chamber, so that friction between the gasket 7302 and the housing 7303 prevents relative rotation and sequentially fluidly connects the inlet port 7310 to the insulin reservoir. When the pin reaches the end of the spiral groove (described above), continued rotation of the motor forces the sleeve 7301 to rotate until the sleeve opening 7309 faces the outlet port 7311. Upon completion of this portion of the cycle, the motor reverses direction due to operation of the limit switch (described above). As the motor begins to rotate in the opposite direction, friction between the gasket 7302 and the housing 7303 prevents relative rotation, and the pump chamber contracts due to the interaction of the spiral groove and the pin. This forces insulin out of the pump chamber, out the sleeve hole 7309, and into the outlet port 7311. When the limit switch is activated again, the cycle is complete and begins to repeat.

[0125] Although only a few exemplary embodiments of the present invention have been described in detail, those skilled in the art will readily appreciate that many modifications and various combinations of the exemplary embodiments are possible without materially departing from the novel teachings and advantages of the present invention, and all such modifications are intended to be included within the scope of the present invention.

Claims

1. a sleeve having a side hole to receive a gasket having a first gasket opening disposed about the side hole, the sleeve and gasket adapted to rotate axially within a housing having an inlet port connected to a fluid reservoir and an outlet port connected to a delivery cannula, the sleeve further comprising a spiral groove having a first end and a second end; a plunger received within the sleeve and adapted to rotate and translate axially within the sleeve, wherein axial translation of the plunger within the sleeve varies a pump volume, the pump volume being in fluid communication with the side bore of the sleeve, the plunger further comprising a coupling member adapted to move within the spiral groove and between the first and second ends of the spiral groove to translate the plunger axially within the sleeve as the plunger rotates; a motor adapted to rotate the plunger in a first direction to increase the pump volume when the sleeve is in a first orientation, and to rotate the sleeve and plunger together when the coupling member reaches the first end of the spiral groove, causing the sleeve to move to a second orientation; an output gear that transmits the movement of the motor to the plunger, the gasket is cylindrical and is assembled onto the sleeve such that the sleeve is received within the cylindrical gasket; The gasket forms a seal between the sleeve and the housing to allow fluid to pass through the first gasket opening between the pump volume and the inlet port or the outlet port.

2. 10. The rotary metering pump of claim 1, wherein the gasket further includes a second gasket opening disposed opposite the first gasket opening.

3. 2. The rotary metering pump of claim 1, wherein the gasket further includes recesses on either side of the first gasket opening facing the housing.

4. A rotary metering pump as described in claim 1, wherein the pump volume and the first gasket opening are aligned with the inlet port or the outlet port of the housing.

Images