Rotary metering pump for insulin patches

Abstract

This invention relates to a rotary metering pump for insulin patches. A rotary pump for a fluid metering system is provided. The rotary pump reciprocates and is reversed by a signal from a limit switch, which is deflected by an actuator arm on a rotating sleeve of the pump system. The rotary pump includes a plunger and an optional stopper formed by a two-stage injection molding process, and includes seals overmolded on the heads of the plunger and the optional stopper.

Description

[0001] Related applications

[0002] This application is a continuation-in-part of U.S. Patent Application No. 16 / 050,159, filed July 31, 2018, which is a continuation-in-part of U.S. Patent Application No. 15 / 300,695, filed September 29, 2016, which is the U.S. national phase of International Application No. PCT / US2015 / 024517, filed April 6, 2015, claiming priority to U.S. Provisional Application No. 61 / 976,361, filed April 7, 2014. The entire contents of each of these applications are incorporated herein by reference. Technical Field

[0003] This invention generally relates to a metering system for wearable drug infusion patches. Background Technology

[0004] Diabetes is a group of diseases characterized by high blood sugar levels, caused by defects in insulin secretion, impaired insulin action, or both. Diabetes can lead to serious health complications and premature death, but well-known products can help manage the disease and reduce the risk of complications.

[0005] Treatment options for people with diabetes include a customized diet, oral medications, and / or insulin therapy. The primary goal of diabetes management is to control a patient's blood glucose (sugar) levels, thereby increasing the likelihood of a life free of complications. However, achieving good diabetes management while balancing other life needs and conditions is often not easy.

[0006] Currently, there are two main modalities for daily insulin therapy in the treatment of type 1 diabetes. The first modality involves syringes and insulin pens, which require a needle prick for each injection, typically three to four times a day. These devices are simple to use and relatively inexpensive. Another widely adopted and effective treatment for managing diabetes is the use of an insulin pump. By providing a continuous infusion of insulin at varying rates to more realistically mimic the behavior of the pancreas, insulin pumps can help users maintain their blood sugar levels within a target range based on their individual needs. By using an insulin pump, users can adapt their insulin therapy to their lifestyle, rather than adapting their lifestyle to how insulin injections work for them.

[0007] However, conventional insulin pumps have several drawbacks. For example, the lead screw and piston-type metering system typically used in insulin pumps are usually bulky for users, requiring a large height and occupying a large area.

[0008] Conventional insulin pumps typically require a large number of parts and moving components, which increases the risk of mechanical failure.

[0009] Conventional insulin pumps typically have excessively long dose accuracy tolerance loops that rely on too many factors, sometimes of which are difficult to identify. This can lead to a loss of dose accuracy.

[0010] Conventional insulin pumps often have overly complex fluid paths. This can lead to complex or inadequate perfusion and air evacuation.

[0011] Conventional insulin pumps typically require high-precision actuators, which increases the cost of conventional patch pumps.

[0012] Some insulin pumps also pose a risk of creating a direct fluid path between the insulin patch container and the cannula. This could lead to users administering an overdose.

[0013] Conventional insulin pumps typically require complex sensing solutions. This leads to increased costs and reduced accuracy and reliability.

[0014] Conventional insulin pumps often also have valves that are prone to leakage under increased system back pressure. This can lead to reduced accuracy and reliability.

[0015] Conventional insulin pumps typically also require large working volumes and large system sizes to expose the patient to potentially high back pressure. This can lead to reduced accuracy and reliability.

[0016] Conventional insulin patches often also have inefficient motors that require large batteries, thus increasing the size of the insulin patch.

[0017] Therefore, there is a need for a metering system that has a reduced height and footprint compared to conventional lead screw and piston-type metering systems, thereby improving user comfort.

[0018] There is also a need for a metering system with fewer components and moving parts compared to a conventional insulin pump, thereby improving the mechanical safety of the insulin patch.

[0019] There is also a need for a metering system that has a shorter dose accuracy tolerance loop that depends on a few factors compared to conventional metering pumps, thereby improving dose accuracy.

[0020] A metering system with a simpler fluid path than conventional metering systems is also needed to simplify filling and air removal.

[0021] There is also a need for a metering system that uses a low-precision actuator compared to conventional metering systems, thereby reducing the cost of insulin patches.

[0022] There is also a need for a metering system that has no direct fluid path between the container and the cannula compared to conventional metering systems, so as to better ensure that users do not overdose.

[0023] There is also a need for a metering system with a simpler sensing scheme compared to conventional metering systems, thereby reducing costs and improving the accuracy and reliability of insulin patches.

[0024] There is also a need for a metering system with valves that are robust against leakage under elevated system back pressure compared to conventional metering systems, thereby improving the accuracy and reliability of insulin patches.

[0025] There is also a need for a metrology system with a small working volume and low system volume exposed to potentially high back pressure compared to conventional metrology systems, thereby improving the accuracy and reliability of insulin patches.

[0026] 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 insulin patches. Summary of the Invention

[0027] One aspect of the illustrative embodiments of the present invention is to substantially solve the above and other problems and provide a small and reliable metering system.

[0028] One aspect of the illustrative embodiments of the present invention is to provide a metering system that has a reduced height and occupied area compared to conventional lead screw and piston-type metering systems, thereby improving user comfort.

[0029] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that has a reduced number of components and moving parts compared to a conventional insulin pump, thereby increasing the mechanical safety of the insulin patch.

[0030] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that, compared to conventional metering pumps, has a short dose accuracy tolerance loop that depends on a few factors, thereby improving dose accuracy. For example, in the illustrative embodiments of the present invention, the tolerance loop for dose accuracy is short and depends only on two easily measurable dimensions: the pump diameter and the axial dimension of the helical groove.

[0031] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that has a simpler fluid path compared to conventional metering systems, thereby simplifying filling and air removal.

[0032] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that utilizes a low-precision actuator compared to conventional metering systems, thereby reducing the cost of insulin patches. For example, in an illustrative embodiment of the invention, the mechanism can over-rotate at both ends of the stroke while still maintaining dosage accuracy.

[0033] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that, compared with conventional metering systems, has no direct fluid path between the container and the cannula, thereby better ensuring that the user does not overdose.

[0034] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that has a simple sensing scheme compared to conventional metering systems, thereby reducing costs and increasing the accuracy and reliability of insulin patches. For example, in an illustrative embodiment of the present invention, the sensing scheme is based on a contact switch.

[0035] Another aspect of the illustrative embodiments of the present invention is to provide a metering system in which the mechanical stroke of the pump allows for simple triggering of the cannula insertion mechanism.

[0036] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that, compared to conventional metering systems, has a valve that is robust against leakage under elevated system back pressure, thereby improving the accuracy and reliability of insulin patches. For example, in the illustrative embodiments of the invention, the valve does not change volume when moving between different states.

[0037] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that, compared with conventional metering systems, has a small working volume exposed to potentially high back pressure and a low system volume, thereby improving the accuracy and reliability of insulin patches.

[0038] Another aspect of the illustrative embodiments of the present invention is to provide a metering system that uses a high-efficiency motor with a small battery, thereby reducing the size of the insulin patch compared to conventional metering systems.

[0039] The foregoing and / or other aspects of the present invention are achieved by providing a metering system for use in a wearable insulin infusion patch. For example, in an illustrative embodiment of the invention, the metering system is part of a larger fluid subsystem that includes a flexible container for storing insulin and a cannulation assembly for delivering insulin into subcutaneous tissue. The metering system draws a small dose of fluid from the container and then pushes it into the patient along the cannulation line. The fluid dose is small relative to the container volume, requiring many pump strokes to completely empty the container.

[0040] Additional and / or other aspects and advantages of the invention will be set forth in the description which follows, or will be apparent from the description, or may be learned by practice of the invention. The invention may include a method, apparatus, or system having one or more of the foregoing aspects, and / or one or more of the features, and combinations thereof. The invention may include, for example, one or more of the features recited in the appended claims, and / or combinations thereof. Attached Figure Description

[0041] The various objects, advantages, and novel features of the illustrative embodiments of the present invention will be more readily understood when the following detailed description is read in conjunction with the accompanying drawings, in which:

[0042] Figure 1 An architectural diagram of an illustrative embodiment of the patch pump according to the present invention is shown;

[0043] Figure 2 A diagram showing the arrangement of fluid and metering system components according to an illustrative embodiment of a patch pump according to the present invention is provided.

[0044] Figure 3 A schematic exploded view of the metering subsystem according to an illustrative embodiment of the patch pump according to the present invention is shown;

[0045] Figure 4 A layout diagram of the metering subsystem according to an illustrative embodiment of the patch pump according to the present invention is shown;

[0046] Figure 5 A schematic cross-sectional view of a metering subsystem according to an illustrative embodiment of a patch pump according to the present invention is shown;

[0047] Figure 6A and 6B Multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the present invention are shown in the starting position;

[0048] Figure 7A and 7B Multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention during the suction stroke are shown;

[0049] Figure 8A , 8B Figures 8C and 8C show multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention during a valve state change after the suction stroke;

[0050] Figure 9A and 9B Multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention are shown in the suction stroke stop position;

[0051] Figure 10Aand 10B Multiple views of the metering subsystem of an illustrative embodiment of a patch pump according to the invention are shown during the discharge stroke;

[0052] Figure 11A , 11B Figures 11C and 11C show multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention during a valve state change after the discharge stroke;

[0053] Figure 12A and 12B Several views of the metering subsystem of an illustrative embodiment of the patch pump according to the present invention are shown after the pump cycle is completed;

[0054] Figure 13 An exploded view of the metering subsystem according to an illustrative embodiment of the patch pump according to the present invention is shown;

[0055] Figure 14 A schematic exploded view of a pump assembly according to an illustrative embodiment of a metering pump according to the present invention is shown;

[0056] Figure 15 A schematic exploded view of the motor and gearbox assembly according to an illustrative embodiment of the metering pump according to the present invention is shown;

[0057] Figure 16A , 16B Figures 16C and 16D illustrate several schematic diagrams illustrating a method of assembling a piston into a sleeve according to the present invention;

[0058] Figure 17A , 17B Figures 17C and 17C show several schematic diagrams illustrating a method of assembling a plug into a sleeve according to the present invention;

[0059] Figure 18A , 18B Figures 18C and 18D illustrate several schematic diagrams illustrating a method of assembling a sleeve into a manifold according to the present invention;

[0060] Figure 19 This is a schematic cross-sectional view of a pump assembly according to an illustrative embodiment of a patch pump according to the present invention;

[0061] Figure 20A , 20B Figures 20C, 20D, and 20E show several schematic cross-sectional views illustrating a method for changing the valve state according to the present invention;

[0062] Figure 21A , 21B Figures 21 and 21C show multiple views of a limit switch for pump and sleeve rotation in a metering subsystem according to an illustrative embodiment of a patch pump according to the invention;

[0063] Figure 22A , 22B Figures 22C and 22C show several schematic cross-sectional views illustrating a method of assembling a pump into a gearbox according to the present invention;

[0064] Figure 23A , 23B 23C shows multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention in the starting position;

[0065] Figure 24A and 24B Multiple views of the metering subsystem of an illustrative embodiment of a patch pump according to the invention are shown during the discharge stroke;

[0066] Figure 25A , 25B Figures 25C and 25C show multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention during a valve state change after the discharge stroke;

[0067] Figure 26A and 26B Multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention are shown in the discharge rotation stop position;

[0068] Figure 27A and 27B Multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention during the suction stroke are shown;

[0069] Figure 28A , 28B Figures 28C and 28C show multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention during a valve state change after the suction stroke;

[0070] Figure 29A and 29B Multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention are shown in the suction rotation stop position;

[0071] Figure 30A , 30B Figures 30C and 30C show multiple views of the metering subsystem of an illustrative embodiment of the patch pump according to the invention after the pump cycle is completed.

[0072] Figure 31A , 31B Figures 31C and 31C show multiple views of a motor and gearbox assembly and a modified pump assembly according to an illustrative embodiment of a metering component based on the present invention.

[0073] Figure 32An exploded view of a pump assembly according to an illustrative embodiment of the metering component of the present invention is shown;

[0074] Figure 33A and 33B An exemplary embodiment of the patch pump according to the present invention is shown, showing the assembly of the piston into the sleeve;

[0075] Figure 34A , 34B 34C, 34D, and 34E illustrate illustrative embodiments of the patch pump according to the invention, showing the assembly of a sleeve into a manifold;

[0076] Figure 35 A cross-sectional view of the sleeve and manifold assembly according to an illustrative embodiment of the patch pump according to the present invention is shown;

[0077] Figure 36A , 36B 36C shows multiple cross-sectional views illustrating the change in valve state of an exemplary embodiment of the patch pump according to the invention as the sleeve rotates;

[0078] Figure 37A , 37B 37C and 37D show illustrative embodiments of a sleeve rotation limit switch for a patch pump according to the present invention;

[0079] Figure 38A and 38B An exploded view of a pump assembly having an elastomeric port and a piston seal respectively overmolded onto a manifold and a pump piston, according to an illustrative embodiment of the patch pump of the present invention, is shown.

[0080] Figure 39A , 39B 39C and 39D show exploded views of a pump assembly with an alternative rotary limit switch design according to an illustrative embodiment of the patch pump according to the present invention;

[0081] Figure 40 An exploded view of an illustrative embodiment of the metering component according to the present invention is shown;

[0082] Figure 41 It shows Figure 40 Assembly diagram of the metering components;

[0083] Figure 42 It shows Figure 40 A cross-sectional view of the metering components;

[0084] Figure 43A , Figure 43B and Figure 43C An interlocking component according to an illustrative embodiment of the present invention is shown. Figure 40 The interaction between the sleeves of the metering components;

[0085] Figure 44 A cross-sectional view of another illustrative embodiment of the metering component according to the present invention is shown;

[0086] Figure 45 This is an isometric view of a limit switch and actuator arm that can be used in alternative exemplary embodiments of the present invention;

[0087] Figure 46 It is based on Figure 45 Isometric views of the limit switch and rotating sleeve in an embodiment;

[0088] Figure 47 yes Figure 45 Top view of the limit switch;

[0089] Figure 48 yes Figure 45 Top view of the limit switch and actuator arm;

[0090] Figure 49 yes Figure 46 End view of the rotating sleeve;

[0091] Figure 50 yes Figure 45 A sectional elevation view of the limit switch and actuator arm;

[0092] Figure 51A and Figure 51B This is a graph illustrating the relative displacement of the limit switch and the rotating sleeve according to an exemplary embodiment of the present invention;

[0093] Figures 52 to 58 Different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention are shown;

[0094] Figures 59 to 62 It shows the use of Figures 52 to 58 Different perspective views of the improved plunger overmolded seal;

[0095] Figures 62 to 67 Different perspective views of the improved pump plug are shown;

[0096] Figure 68 This is an exploded view of a pump system with an improved plunger, plug, and overmolded seal utilizing exemplary embodiments of the present invention.

[0097] Figure 69 This is a flowchart of a method for manufacturing a pump according to an exemplary embodiment of the present invention.

[0098] In all the accompanying drawings, similar reference numerals should be understood to refer to similar elements, features, and structures. Detailed Implementation

[0099] As those skilled in the art will understand, there are various ways to implement metering systems according to embodiments of the invention disclosed herein. Although reference will be made to the illustrative embodiments depicted in the accompanying drawings and the following description, the embodiments disclosed herein are not intended to be exhaustive of the various alternative designs and embodiments covered by the disclosed invention, and it will be readily understood by those skilled in the art that various modifications and combinations can be made without departing from the invention.

[0100] Although various persons, including but not limited to patients or healthcare professionals, may operate or use the illustrative embodiments of the invention, for the sake of simplicity, the operator or user will be referred to as "user" hereinafter.

[0101] Although various fluids may be used in the illustrative embodiments of the invention, for the sake of simplicity, the liquid in the injection device will be referred to as "fluid" hereinafter.

[0102] exist Figures 1 to 3 0 illustrates an illustrative embodiment of the invention. In this illustrative embodiment, a metering system for a wearable insulin infusion patch is provided. For example, in this illustrative embodiment, the metering system is part of a larger fluid subsystem including a flexible container for storing insulin and a cannulation assembly for delivering insulin into subcutaneous tissue. The metering system draws a small dose of fluid from the container and then pushes it into the patient along the cannulation line. The fluid dose is small relative to the container volume, requiring many pump strokes to completely empty the container.

[0103] Figure 1 A schematic diagram of a patch pump 100 according to an exemplary embodiment of the present invention is shown. The patch pump 100 includes a fluid subsystem 120, an electronic component subsystem 140, and a power storage subsystem 160.

[0104] The fluid subsystem 120 includes a filling port 122 in fluid communication with a container 124. The container 124 is adapted to receive fluid from a syringe through the filling port.

[0105] The fluid subsystem 120 also includes a volume sensor 126 mechanically coupled to the container 124. The volume sensor 126 is adapted to detect or determine the volume of fluid within the container.

[0106] The fluid subsystem 120 also includes a metering subsystem 130, which 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 container 124 of the fluid subsystem 120 and is actuated by the pump and valve actuator 134.

[0107] The fluid subsystem 120 also includes a cannulation mechanism having a deployment actuator 128 mechanically coupled to a cannula 129. The deployment actuator 128 is adapted to insert the cannula 129 into the user's body. The cannula 129 is in fluid communication with the integrated pump and valve system 132 of the metering subsystem 130.

[0108] The fluid subsystem 120 also includes a blockage sensor 136 mechanically coupled to the fluid path between the cannula 129 and the integrated pump and valve system 132. The blockage sensor 136 is adapted to detect or determine a blockage in the passage between the cannula 129 and the integrated pump and valve system 132.

[0109] The electronic component subsystem 140 includes a volume sensing electronics 142 electrically connected to a volume sensor 126 of the fluid subsystem 120, a pump and valve controller 144 electrically connected to a pump and valve actuator 134 of the metering subsystem 130, a blockage sensing electronics 146 electrically connected to a blockage sensor 136 of the fluid subsystem 120, and optionally an deployment electronics 148 electrically connected to a cannula 129 of the fluid subsystem. The electronic component subsystem 140 also includes a microcontroller 149 electrically connected to the volume sensing electronics 142, the pump and valve controller 144, the blockage sensing electronics 146, and the deployment electronics 148.

[0110] The power storage subsystem 160 includes a battery 162 or any other electrical power source known in the art. The battery 162 may be adapted to power any component or electronic part of the patch pump 100.

[0111] Figure 2 A diagram showing the arrangement of fluid and metering system components of a patch pump 200 according to an exemplary embodiment of the present invention is provided. The patch pump 200 includes a metering subsystem 230, control electronics 240, a battery 260, a container 222, a filling port 224, and a cannulation mechanism 226. The components of the patch pump 200 are substantially similar to those of the illustrative patch pump 100, which is labeled with similar reference numerals, and interact substantially similarly to the components of the illustrative patch pump 100.

[0112] Figure 3 This is an exploded view of a metering subsystem 300 of a patch pump according to an exemplary embodiment of the present invention. The metering subsystem 300 includes a DC geared motor 302 mechanically coupled to a pump piston 304 disposed within a pump housing 306. The pump piston 304 is mechanically coupled to a pump housing 308 via a coupling pin 310. The metering subsystem 300 also includes a pump seal 312 between the pump piston 304 and the pump housing 308. The metering subsystem 300 also includes a port seal 314 located on a seal bracket 316 disposed within a valve housing 318.

[0113] In an exemplary embodiment of the invention, the output shaft 320 of the DC geared motor can rotate 360° in any direction. The pump piston 304 can rotate 360° in any direction and can translate approximately 0.050 inches. The pump housing 308 can rotate 180° in any direction. The pump housing 306, port seal 314, seal bracket 316, and valve housing 318 are preferably fixed.

[0114] The metering subsystem 300 includes a volumetric pump with an integrated flow control valve and mechanical actuator, and a drive system. The pump includes a piston 304 and a rotary-actuated selector valve. The metering system draws precise volumes of insulin from a flexible container into a pump volume 320 formed between the piston 304 and the pump housing 308 (see [link to relevant documentation]). Figure 5 The insulin volume is then pushed into the patient's subcutaneous tissue through the cannula, thus administering insulin in discontinuous, small doses. The pump stroke creates positive and negative pressure gradients within the fluid path, inducing flow. The stroke and pump volume diameter determine the nominal size and accuracy of the dose. A fluid control valve actively travels back and forth between the container and the cannula fluid port at each end of the pump stroke, alternately blocking and opening the port to ensure unidirectional fluid flow (from container to patient) and to ensure no free flow is possible between the container and the patient.

[0115] Figure 4 This is an assembly diagram of a metering subsystem 300 according to an exemplary embodiment of the present invention. A motor-to-piston connector 322, a piston-to-pump housing connector 324, a container port 326, and a cannula port 328 are also shown.

[0116] Figure 5 This is a cross-sectional view of a metering subsystem 300 according to an exemplary embodiment of the present invention. As shown, a pump volume 320 is formed between the piston and the pump housing 308. The pump housing includes a side port 330, which is alternately oriented between a container port 326 and a cannula port 328 when the motor 302 causes the pump to reciprocate, as will be described in more detail below.

[0117] In operation, the illustrative cycle of the metering system according to the invention comprises four steps: 180° pump intake (counterclockwise) (viewed from the pump toward the motor); 180° valve state change (counterclockwise); 180° pump discharge (clockwise); and 180° valve state change (clockwise). A complete cycle requires a full rotation (360°) in each direction.

[0118] Figure 6A This is an isometric view of the metering subsystem 300 in its initial position. Figure 6BThis is a cross-sectional view. In the initial position, the pump piston 302 is fully extended, the pump housing blocks the flow path at the cannula port 328, and the container port 326 is open toward the side port 330 of the pump housing 308, with the rotation limit sensor 332 engaged. The pump housing 308 includes a helical groove 334 that receives the coupling pin 310. The piston 304 is slidably engaged with the pump housing 308 such that 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, thereby forcing the piston 304 to translate axially 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.

[0119] Figure 7A This is an isometric view of the metering subsystem 300 during the suction stroke. Figure 7B This is a cross-sectional view. The DC motor 302 rotates the pump piston 304, which is driven (rotational and translational) along a helical groove 334 of the pump housing 308 via a connecting pin 310. The pump piston 304 translates toward the DC motor 302, thereby drawing fluid into the increasing pump volume 320. During the suction stroke, the friction between the seal and the outer diameter of the pump housing 308 is preferably high enough to ensure that the pump housing 308 does not rotate. The pump housing 308 is stationary, while the pump volume 320 is increasing. The insertion port 328 is blocked, while the container port 326 is open to the fluid flowing into the increasing pump volume 320. There is a sliding engagement between the motor 302 and the pump piston 304.

[0120] Figure 8A This is an assembly diagram of the patch pump during the valve state change period after the suction stroke. Figure 8B These are detailed images. Figure 8CThis is a cross-sectional view. Torque is transmitted from the drive shaft of motor 302 to pump piston 304, and then to pump housing 308 via connecting pin 310. Once connecting pin 310 rotates to the end of helical groove 334, continued rotation of motor 302 causes connecting pin 310 to cause pump housing 308 and pump piston 304 to rotate together as a whole without relative axial translation. Side port 330 on pump housing 308 rotates between container port 326 and insertion port 328. Surface tension of side port 330 of pump housing 308 retains fluid in pump volume 320. After the next 180° rotation of motor 302, side port 330 of pump housing moves out of alignment with container port 326 and into alignment with insertion port 328. In between, both insertion port 328 and container port 326 are blocked. Connecting pin 310 is located at the end of helical groove 334 and transmits torque to pump housing 308. The connecting pin 310 locks the pump piston 304 and the pump housing 308 together to prevent relative axial movement between the two components. Therefore, the pump piston 304 and the pump housing 308 rotate as a whole and do not translate relative to each other. The pump housing 308 rotates while the pump volume 320 remains fixed and the pump piston 304 rotates. The seal 314, seal bracket, and valve housing 318 are preferably fixed.

[0121] Figure 9A This is an assembly diagram of the metering subsystem in the stop position of the suction stroke, ready for infusion. Figure 9B This is a cross-sectional view. As shown, the side port 330 of the pump housing 308 is aligned with the insertion port 328, the pump volume 320 is increased, and the container port 326 is blocked. The rotation limit sensor 332 engages via a feature on the rotating pump housing 308. The motor 302, pump piston 304, and pump housing 308 are fixed.

[0122] Figure 10A This is an assembly diagram of the metering subsystem 300 during the discharge process. Figure 10BThis is a cross-sectional view. At the end of the suction stroke, the pump housing 308 engages the limit switch 332, which causes the DC motor 302 to switch directions. Therefore, the motor 302 rotates the piston 304 and drives the coupling pin 310 along the helical groove 334 of the pump housing 308, thereby causing the piston 304 to translate axially. The pump piston 304 translates axially away from the DC motor 302, thereby displacing fluid from the pump volume 320 through the insertion port 328 into the insertion tube. During the discharge stroke, the 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 insertion port 328 is open to the fluid flowing out of the shrinking pump volume 320. The container port 326 is blocked. The pump housing 308 is stationary, while the pump volume 320 shrinks and the pump piston 304 rotates and translates in a helical motion. The motor is slidably connected to the piston 304 to accommodate the translational movement of the piston as it rotates in the helical groove 334.

[0123] Figure 11A This is an assembly diagram of the metering subsystem 300 during the valve state change period after the discharge stroke. Figure 11B These are detailed images. Figure 11C This is a cross-sectional view. Torque is transmitted from the drive shaft of motor 302 to pump piston 304, and then via coupling pin 310 to pump housing 308. Pump housing 308 and pump piston 304 rotate as a whole without relative axial movement. Side port 330 on pump housing 308 rotates between container port 326 and cannula port 328, both of which are blocked during rotation. The surface tension of side port 330 of pump housing 308 retains fluid in pump volume 320. Coupling pin 310 locks pump piston 304 and pump housing 308 together to prevent relative axial movement between the two components. Therefore, pump piston 304 and pump housing 308 rotate as a whole and do not translate relative to each other. Pump housing 308 rotates while pump volume 320 is fixed. Seal 314, seal bracket, and valve housing 318 are preferably fixed.

[0124] Figure 12A This is an assembly diagram of the metering subsystem 300 after the pump cycle is complete. Figure 12B This is a cross-sectional view. The pump mechanism (piston 304) is fully extended, thus completing the pump cycle. The rotation limit sensor 332 is engaged to reverse the motor 302 and restart the pump cycle. The cannula port 328 is blocked, while the container port 326 is open to the flow path from the container.

[0125] In the aforementioned exemplary embodiments, the pump piston both rotates and translates, the pump housing rotates, and the valve housing is fixed. 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, and the valve housing translates, or any other combination of movements that cause the pump volume to increase and decrease, and the port communicating with the pump volume moves from alignment with the container port to alignment with the cannula port.

[0126] In the aforementioned exemplary embodiment, the pump stroke and valve state change are configured to have 180° rotational actuation from the motor. However, it should be understood that any suitable angle can be selected for each segment of the pump cycle.

[0127] In the aforementioned exemplary embodiments, an atmospheric break exists between the cannula and the container port during a valve state change. However, it should be understood that in other embodiments, a seal may be constructed or additional seals may be added to eliminate the atmospheric break and seal the pump and valve system during a state change.

[0128] In the foregoing exemplary embodiments, a DC geared motor is used to drive the pump and valve. However, in other embodiments, any suitable drive mechanism can be provided to drive the pump and valve. For example, a solenoid, nitinol wire, voice coil actuator, piezoelectric motor, wax motor, and / or any other type of motor known in the art can be used to drive the pump.

[0129] In the foregoing exemplary embodiments, the pump uses a full discharge stroke. However, it should be understood that in other embodiments, a system with sequentially increasing discharge strokes can be used to dispense finer doses.

[0130] In the aforementioned exemplary embodiment, the pump employs an on / off limit switch to determine the state of the system at the limits of its rotational stroke. However, it should be understood that in other embodiments, other sensors capable of determining intermediate states, such as encoder wheels and optical sensors, can be used to improve the resolution of the sensing scheme.

[0131] It should be understood that the pump's inner diameter can be adjusted to change the nominal output for each cycle.

[0132] In the aforementioned exemplary embodiments, the pump uses an elastomeric O-ring seal. However, it should be understood that other arrangements may also be used. For example, the fluid seal may be molded directly onto the seal holder, other elastomeric seals (e.g., quad rings) may be used, or other sealing materials (e.g., Teflon or polyethylene lip seals) may be used.

[0133] In an alternative embodiment of the invention, the movement of the pump can be used to initiate or trigger the deployment of the cannula.

[0134] In the foregoing example, the system advantageously uses bidirectional actuation. The motor rotates in reverse to alternate between inhalation and exhalation strokes. This provides a safety feature to prevent loss of control in the event of motor failure. The motor must reciprocate so that the pump continuously delivers the medication from the container. However, it should be understood that in other embodiments, the metering system is designed to use a unidirectional actuator.

[0135] In the foregoing exemplary embodiments, the system uses a bag-shaped container with two flexible walls. However, in other embodiments, the container can be formed in any suitable manner, including having one rigid wall and one flexible wall.

[0136] Figure 13 This is an exploded view of a metering subsystem 1300 for a patch pump according to another illustrative embodiment of the present invention. The metering subsystem 1300 includes a motor and gearbox assembly 1302 and a pump assembly 1304.

[0137] Figure 14 This is an exploded view of pump assembly 1304. Pump assembly 1304 includes a piston 1306 mechanically connected to sleeve 1308 via a coupling pin 1310 within pump manifold 1312. Pump assembly 1304 also includes a port seal 1314, a plug 1316, a sleeve rotation limit switch 1318, and an output gear rotation limit switch 1320.

[0138] Piston 1306 rotates a total of 196° in either direction and can translate approximately 0.038 inches. Sleeve 1308 and plug 1316 rotate together (in pairs) 56° in either direction. Pump manifold 1312 and port seal 1314 are fixed.

[0139] Figure 15 This is an exploded view of the motor and gearbox assembly 1302. The motor and gearbox assembly 1302 includes a gearbox cover 1322, a combination gear 1324, an output gear 1326, a shaft 1328, a gearbox base 1330, a motor pinion 1322, and a DC motor 1334.

[0140] Figures 16A-16D The assembly and operation of piston 1306, sleeve 1308 and connecting pin 1310 are shown. Figure 16AA piston 1306 is shown, comprising a press-fit hole 1338 for receiving a coupling pin 1310 and a piston seal 1340 that tightly seals the piston within a sleeve 1308. The sleeve 1308 includes a helical groove 1342. The piston 1306 is axially pressed into the sleeve 1308, and then the coupling pin 1310 is press-fitted into the hole 1338 through the helical groove 1342. This provides operation similar to the embodiments described above, wherein rotation of the piston 1306 due to the interaction of the coupling pin 1310 and the helical groove 1342 causes axial translation of the piston 1306 relative to the sleeve 1308. Figure 16B The assembled piston 1306, sleeve 1308 and connecting pin 1310 are shown, with the connecting pin 1310 shown at the lower end of the spiral groove 1342. Figure 16C The axial travel length 1344 of the piston 1306 relative to the sleeve 1308 is shown due to the spiral groove 1342. Figure 16D A tapered surface 1346 is shown, which is preferably located at the end of the spiral groove 1342 so that the connecting pin 1310 is centered within the groove 1342.

[0141] Figure 17A The assembly of plug 1316 and sleeve 1308 is shown. As shown, plug 1316 includes a key 1346 and a seal 1348. Seal 1348 allows the plug to fit tightly within sleeve 1308. Sleeve 1308 has a recess 1350 adapted to receive key 1346. Key 1346 locks plug 1316 into rotational engagement with sleeve 1308. During assembly, plug 1316 is pressed against the end face of (forward) piston 1306 to minimize air in the pump chamber. Friction between seal 1348 and the inner surface of sleeve 1308 axially holds plug 1316. With appropriate selection of seal diameter, compression, and material, plug 1316 can also function as a clogging or overpressure sensor. Pump pressure exceeding a threshold will cause plug 1316 to move axially and disengage from sleeve rotation limit switch 1318. Friction resistance below the desired threshold pressure keeps stopper 1316 in place. Figure 17B and 17C The axial movement of piston 1306 within sleeve 1308 is shown. Figure 17B The piston 1306 is shown in its first state, where the pump volume between the piston 1306 and the plug 1316 is minimal or zero. As shown, the connecting pin 1310 abuts against the lowest end of the spiral groove 1342. Figure 17C The piston 1306 is shown in its second state, where the pump volume 1352 between the piston 1306 and the plug 1316 is at its maximum. As shown, the connecting pin 1310 abuts against the highest end of the spiral groove 1342.

[0142] Figures 18A-18DThe assembly of sleeve 1308 into manifold 1312 is shown. Figure 18A As shown, manifold 1312 includes port seals 1314 to seal container port 1354 and cannula port 1356, respectively. A small side hole 1358 on the sleeve (see...) Figure 17B It rotates back and forth between two ports spaced 56 degrees apart. (For example...) Figure 18B As shown, sleeve 1308 includes a protrusion 1360, and manifold 1312 includes a corresponding groove 1362 to allow sleeve 1308 to be assembled into manifold 1312. Figure 18C A manifold window 1364 disposed in the manifold 1312 is shown. When the sleeve 1308 is assembled into the manifold 1312, the protrusion 1360 is received in and travels within the window 1364. The protrusion 1360 and the window 1364 interact to allow the sleeve 1308 to rotate between two positions while preventing axial translation of the sleeve 1308 relative to the manifold 1312. The sleeve 1308 rotates between a first position in which the side hole 1358 is aligned with the container port 1354, and in the second position in which the side hole 1358 is aligned with the cannula port 1356. Figure 18D A sleeve 1308 assembled into manifold 1312 is shown, wherein a protrusion 1360 is located within manifold window 1364.

[0143] Figure 19 This is a cross-sectional view of the assembled metering system. As shown, the port seal 1314 is a face seal compressed between the outer diameter of the sleeve 1308 and the recess in the manifold 1312. Also shown, a protrusion 1360 is located within the manifold window 1364, and a side hole 1358 is shown in the transition between the container port 1354 and the cannula port 1356. The output gear 1326 includes a cam feature 1366 that engages with a rotary limit switch 1320 to indicate the end of rotational movement of the piston 1306 and the sleeve 1308 in either direction.

[0144] Figures 20A-20E It is a cross-sectional view showing the sleeve 1308 rotating within the manifold 1312 to move the side hole from alignment with the container port 1354 to alignment with the cannula port 1356. Figure 20A A side hole 1358 aligned with container port 1354 is shown. In this position, piston 1306 is removed from plug 1316 to fill volume 1352 with fluid from the container. Figure 20B The sleeve 1308 is shown when it begins to rotate toward the cannula port 1356. In this position, the side hole 1358 is sealed by a seal 1314 on the container port 1354. Therefore, the diameters of the seal 1314 and the side hole 1358 are preferably chosen such that the seal 1314 covers the opening of the side hole 1358. Figure 20C A side hole 1358 of a sleeve 1308 is shown between the seal 1314 at container port 1354 and the seal 1314 at cannula port 1356. In this position, neither seal 1314 blocks the side hole 1358, but the surface tension of the liquid keeps the liquid in the pump chamber. Figure 20D This shows the position where the side hole 1358 is further rotated until the seal 1314 covers the opening of the side hole 1358 at the insertion port 1356. Finally, Figure 20E The side port 1358 is shown rotated to align with the insertion port 1356. Simultaneously, in this position, the piston 1306 is axially translated to reduce the volume 1352, thereby forcing fluid to flow out from the insertion port 1356 and into the insertion cannula.

[0145] Figures 21A-21C The operation of the limit switch is shown. For example... Figure 21A As shown, the stopper 1316 includes a cam feature 1368 that interacts with a limit switch 1318. As the sleeve 1308 and the stopper 1316 rotate, the cam feature 1368 contacts the metal flexible elements of the limit switch 1318 against each other until the stopper 1316 has fully rotated to the next position. When the stopper 1316 is at either end of its rotation, a protrusion 1370 in one of the flexible elements rests against the cam feature 1368, as... Figure 21C As shown in the diagram, opening and closing the limit switch 1318 during each rotation cycle instructs the plug 1316 to remain properly aligned with the limit switch 1318. In the event of overpressure or blockage, the increased pressure will cause the plug 1316 to slide out of the sleeve 1308 and disalign with the limit switch 1318. Therefore, an overpressure condition is detected. At the end of each rotation cycle, the limit switch 1320 is engaged by the cam feature 1366 of the output gear 1326. This informs the motor 1344 to reverse. As shown, it is impossible to determine which rotation cycle has been completed from the limit switches using only two flexible metal elements. However, it will be appreciated that a third flexible element will allow the engagement direction to be determined.

[0146] Figures 22A-22C The assembly of the motor and gearbox 1302 with the pump assembly 1304 is shown. (As...) Figure 22A and 22BAs shown, the motor and gearbox 1302 includes an opening 1372 for receiving a rotary limit switch 1320. In this way, the output gear 1326, located inside the gearbox housing, can access and engage the flexible element of the limit switch 1320. The motor and gearbox 1302 also includes an axially retaining snap 1374, allowing the pump assembly 1304 to snap into the motor and gearbox 1302. The motor and gearbox 1302 includes a rotary key 1376 within a pump receiving slot 1378 to receive the pump assembly 1304 and prevent rotation of the pump assembly 1304 relative to the motor and gearbox 1302. The output gear 1326 includes a protrusion 1382 adapted to receive a piston 1306. Figure 22C ) slot 1380 ( Figure 22B During assembly, protrusion 1382 is received into slot 1380, allowing output gear 1326 to transmit torque to piston 1306. As output gear 1326 rotates, protrusion 1382 on the pump piston both rotates and slides axially within the slot. Metal spring flexures on the motor connector and limit switch are used for electrical contact with the disc on the circuit board during final assembly.

[0147] During operation, the pump cycle of the aforementioned embodiment comprises five steps. First, approximately 120° pump discharge (counterclockwise when viewed from the pump towards the gearbox); 56° valve state change (counterclockwise); 140° pump intake (clockwise); 56° valve state change (clockwise); and approximately 20° jerking (counterclockwise) to clear the limit switch. The entire pump cycle requires the output gear to rotate 196 degrees in each direction.

[0148] Figure 23A-30C The pump cycle is shown. For clarity, only the output gear 1326 of the gearbox assembly 1302 is shown in the accompanying drawings.

[0149] Figure 23A The initial position is shown. As shown, the cam 1366 of the output gear 1326 is not in contact with the rotation limit switch 1320, preventing the flexible components from contacting each other. The pump piston 1306 retracts, as... Figure 22C The position of the connecting pin 1310 within the spiral groove 1342 is shown. In this position, the sleeve 1308 blocks the container flow path, the insertion port 1356 opens into the side hole 1358 of the sleeve 1308, and the rotation limit sensor 1320 and the sleeve sensor 1318 (see...) Figure 23B All are open.

[0150] Figure 24A and 24B The metering subsystem during the discharge stroke is shown. Output gear 1326 rotates in the first direction (see...). Figure 24B(The arrow in the image) rotates the pump piston 1306, which is driven via the connecting pin 1310 along the helical path of the helical groove 1342 in the sleeve 1308 (see [link]). Figure 24A As the pump piston 1306 rotates, it translates away from the gearbox, thereby discharging fluid from the pump chamber 1352 to the insertion port 1356. During the discharge stroke, the 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 portion of the circulation.

[0151] Figures 25A-25C The metering subsystem is shown during the valve state change after the discharge stroke. (Example) Figure 25A As shown, after the connecting pin 1310 reaches the distal end of the helical groove 1342, the torque continues to be transmitted from the output gear 1326 to the pump piston 1306, and then via the connecting pin 1310 to the sleeve 1308. The sleeve 1308 and the pump piston 1306 rotate as a whole without relative axial movement. The side hole 1358 on the sleeve 1308 (in...) Figures 25A-25C (Not shown) moves between container port 1354 and cannulation port 1356. Protrusion 1360 moves within window 1364 of manifold 1312 in the direction indicated by the arrow. (As shown) Figure 25B As shown, the sleeve limit switch 1318 is closed by the cam surface of the plug 1316.

[0152] Figure 26A and 26B The metering subsystem is shown in the discharge rotation stop position. The side hole 1358 of the sleeve (in...) Figure 26A (Or not shown in 26B) Aligned with container port 1354, pump volume 1352 is reduced, and insertion port 1356 is blocked. Plug 1316 is in the stop position, and sleeve limit switch 1318 is open. Output gear cam 1366 contacts rotation limit switch 1320 to indicate the end of rotation, causing output gear 1326 to stop and reverse direction.

[0153] Figure 27A and 27B The metering subsystem during the intake stroke is shown. Output gear 1326 along... Figure 27B The pump piston 1306 is rotated in the direction indicated by the arrow. Due to the interaction of the connecting pin 1310 within the helical groove 1364, the piston 1306 translates axially relative to the sleeve 1308. The pump piston 1306 translates toward the gearbox, thereby drawing fluid from the container into the pump chamber 1352. During the suction stroke, the friction between the seal and the outer diameter of the sleeve 1308 should be sufficiently high to ensure that the sleeve 1308 does not rotate relative to the manifold 1312.

[0154] Figures 28A to 28CThe metering subsystem is shown during the valve state change after the intake stroke. The connecting pin 1310 reaches the upper end of the spiral groove 1342, and the motor 1302 continues to transmit torque, causing the sleeve 1308 and piston 1306 to rotate together. The protrusion 1360 on the sleeve 1308... Figure 28A The direction indicated by the middle arrow indicates movement within window 1364 in manifold 1312. As plug 1316 rotates together with sleeve 1308, the cam surface 1368 of plug 1316 closes sleeve limit switch 1318. Sleeve 1308 and pump piston 1306 rotate as a whole without relative axial movement. During this rotation, side hole 1358 of sleeve 1308 moves between container port 1354 and cannula port 1356.

[0155] Figure 29A and 29B The metering subsystem is shown in the suction rotation stop position. In this position, the side hole 1358 of the sleeve 1308 is aligned with the insertion port 1356, the pump volume 1352 increases, and the container port 1354 is blocked. The cam 1366 of the output gear 1326 engages the rotation limit switch 1320 to indicate that rotation is complete. The motor 1302 stops to reverse direction. The sleeve limit switch 1318 opens.

[0156] Figures 30A-30C The metering subsystem is shown after the pump cycle is complete. The output gear cam 1366 abruptly disengages from the rotary switch 1320 and prepares to begin another cycle.

[0157] Figures 31A-31C Another metering system 3100a according to an exemplary embodiment of the present invention is shown. Figure 31A The motor and gearbox assembly 3101 and the modified pump assembly 3100 are shown. The motor and gearbox assembly 3101 is substantially similar to the combination described above. Figure 13-30C The motor and gearbox assembly is shown and described.

[0158] Figure 32 This is an exploded view of pump assembly 3100. 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 a conductive pad, and a sleeve rotation limit switch 3114 with a flexible arm 3128. As shown, the sleeve 3112 with the conductive pad rotates ±56°.

[0159] Pump assembly 3100 includes three flexible arms 3128 that operate as rotary travel limit switches 3114. The rotary travel limit switches 3114 will be described in more detail below. The rotary travel 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 the cannula port.

[0160] Figures 33A-33B The assembly of piston 3108 into sleeve 3112 is shown. In this embodiment, the inner wall 3113 of sleeve 3112 forms the end face of the pump chamber. Features on the piston sleeve are designed to have tolerances to minimize the gap between the end face of piston 3108 and the face of inner wall 3113 of sleeve.

[0161] Figures 34A-34E The assembly of sleeve 3108 into manifold 3102 is shown. As shown, port seal 3104, seal retainer 3106, and sleeve 3112 are inserted into manifold 3102. Small side hole 3115 on sleeve 3112 (see Figure) Figure 34E The sleeve 3112 rotates back and forth between the container port and the cannula port, which are preferably 56 degrees apart. The sleeve 3112 is inserted past the retaining protrusion 3116 in the manifold 3102 (see...). Figure 34D The plug is then screwed into place to prevent axial travel. Because this embodiment prevents or minimizes axial movement of the plug, blockage sensing due to axial movement of the plug is typically not provided.

[0162] Figure 35 A cross-sectional view of the sleeve 3112 and manifold 3102 assembly is shown, taken along an axis passing through the port seal 3104 and through the side port to the manifold 3102. The side port to the manifold 3102 includes a cannula port 3118 and a container port 3120. The port seal 3104 is a face seal that is compressed between the outer diameter of the sleeve 3112 and a recess in the manifold 3102.

[0163] Figures 36A-36C This is a cross-sectional view taken along the axis of the side port as the sleeve 3112 rotates from the container port 3120 to the insertion port 3118, to show the change in valve state. Figure 36A In the initial position shown, the sleeve side hole 3115 is open to the container port 3120. In this position, the insertion port 3118 is blocked. Figure 36B In the intermediate position shown, during the transition, the sleeve side hole 3115 is blocked by the port seal 3104. Figure 36C In the final position shown, the sleeve side hole 3115 is open to the insertion port 3118. In this position, the container port 3120 is blocked.

[0164] Figures 37A-37D The operation of the sleeve rotation limit switch 3114 is illustrated. The three-contact switch design allows the patch system to distinguish between two rotation limits by means of a switch input signal, rather than by software tracking of the sleeve's angular orientation. The manifold 3102 preferably includes a manifold mounting post 3122. The switch contact 3114 is attached to the post 3122 using adhesive, ultrasonic welding, thermoforming, or any other suitable bonding method. The sleeve 3112 includes conductive pads 3124 at its ends. These conductive pads may be printed or overmolded metal inserts or may be provided by any other suitable means. The sleeve rotation limit switch 3114 includes plastic overmolded parts 3126 for spacing and mounting features of the flexible parts. The sleeve rotation limit switch 3114 also includes three metal flexible parts 3128. The manifold 3102 is provided with alignment slots 3130 that receive the flexible parts 3128. Figure 37B As shown, in the first position, the side hole 3115 on the sleeve 3112 is aligned with the insertion port 3118. In this position, the conductive pad 3124 on the sleeve 3112 bridges the middle and right contact points 3128a and 3128b. In the middle position, as... Figure 37C As shown, the side hole 3115 on the sleeve 3112 is located at the intermediate position between ports 3118 and 3120. In this position, both sides of the switch 3114 are open. In the final position, as... Figure 37D As shown, the side hole 3115 on the sleeve 3112 is aligned with the container port 3120. In this position, the conductive pad 3124 on the sleeve 3112 bridges the middle and left contacts 3128b and 3128c.

[0165] The pump described above has a modified operating sequence. Except for no longer requiring a 20° backlash, the operating sequence is essentially the same as described above. The three-contact switch design described above does not require a backlash, and the complete pump cycle consists of the following four parts: First, there is approximately a 140° pump discharge, counterclockwise when viewed from the pump towards the gearbox. Second, there is a 56° valve state change, also counterclockwise. Third, there is a 140° pump suction, clockwise. Fourth, there is a 56° valve state change, clockwise. The entire pump cycle requires the output gear to rotate 196 degrees in each direction.

[0166] Figure 38A and 38B An exploded view of another type of pump assembly is shown, featuring elastomeric ports and piston seals that are overmolded onto the manifold and pump piston, respectively. This type of pump operates in essentially the same manner as the pumps described above, but has fewer separate parts and is easier to assemble. Overmolding the seals directly onto the manifold and piston reduces the number of dimensions that contribute to seal compression, thus allowing for tighter control and less variation in seal performance.

[0167] Figure 39A An exploded view of a pump assembly 3900 with an alternative rotary limit switch design is shown. This type of pump assembly includes a two-contact design for the sleeve rotary limit switch. Using this design, the pump will properly actuate back at the end of the pump cycle, causing the contact switch 3902 to open in the resting state. Figure 39B As shown, in the first position, the side hole 3115 on the sleeve is aligned with the insertion port. In this position, the first rib 3904 on the sleeve forces the contact to close. Figure 39C In the intermediate position shown, the side hole 3115 on the sleeve is located in the middle position between the ports, and neither ribs 3904 nor 3906 are touching the contact switch 3902, therefore it is open. Figure 39D In the third position shown, the side hole 3115 on the sleeve is aligned with the container port. In this position, the second rib 3906 on the sleeve again forces the contact switch 3902 to close.

[0168] Figure 40 This is an exploded view of another exemplary embodiment of the metering assembly 4000. This embodiment shares fundamental similarities with the embodiments described above, therefore the following description focuses on the differences. The metering assembly 4000 includes a sleeve 2004 with a spiral groove 4004, a plug 4006, a seal 4008, a plunger 4010, a connecting pin 4012, a manifold 4014, a port seal 4016, and a flexible interlocking member 4018. Figure 41 The metering components in an assembled configuration are shown. Seals 4008 are preferably formed of an elastomeric material and are structurally monolithic. One seal 4008 is mounted to a plug 4006, and another seal 4008 is mounted to a plunger 4010. Plug 4006 is preferably secured to a sleeve 4002 by gluing, welding, or any other suitable means. The end face of the plug forms one surface of the pump volume. Plunger 4010 is inserted into sleeve 4002, and a connecting pin 4012 is press-fitted into plunger 4010 and extends into a helical groove 4004 to provide axial translation of the plunger when it is rotated by a motor (not shown). The end face of plunger 4010 forms the opposing surface of the pump volume. Port seal 4016 is preferably a single molded elastomeric material piece. This embodiment reduces the number of parts and improves manufacturability. Figure 42 This is a cross-sectional view of the assembled metering assembly.

[0169] Figures 43A-43C The interaction between the interlock 4018 and the sleeve 4002 is shown. (As...) Figure 41 As shown, interlock 4018 is mounted to manifold 4014 at either end. (As...) Figure 43AAs shown, the end face of sleeve 4002 includes a ratchet 4020, which is adjacent to the protrusion 4022 of interlock 4018 when the metering assembly is in the first position (side hole aligned with container pump). In some cases, such as back pressure, friction between plunger 4010 and sleeve 4008 may be sufficient to rotate the sleeve before plunger 4010 and coupling pin 4012 reach either end of spiral groove 4004. This can result in incomplete pumping of liquid volume per stroke. To prevent this, interlock 4018 prevents sleeve 4002 from rotating until the torque exceeds a predetermined threshold. This ensures that plunger 4010 rotates sufficiently within sleeve 4008 until coupling pin 4012 reaches the end of spiral groove 4004. Once coupling pin strikes the end of spiral groove 4004, continued motor movement will increase the torque on sleeve beyond the threshold, causing interlock to flex and allowing ratchet 4020 to pass through protrusion 4022. This... Figure 43B As shown in the diagram, when the rotation of the sleeve 4008 is completed to orient the side hole and the cannula port, the protrusion 4020 moves over the protrusion 4022 in the interlock 4018. This is in Figure 43C Shown in.

[0170] Figure 44 A cross-sectional view of another exemplary embodiment of the metering system 4400 is shown. The metering system 4400 includes a modified sleeve 4402 having a surface 4404 that forms a pump volume. This embodiment eliminates the need for a stopper in the previous embodiment and simplifies manufacturing.

[0171] Figure 45 Another exemplary embodiment with a modified sleeve 4500 and switching mechanism 4502 is shown. Figure 46 This is a perspective view of a modified sleeve 4500, similar to the sleeve described above, which includes a ratchet 4504 to interact with an interlocking element (not shown). The switching 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. Figure 47 This illustrates how the limit switch 4506 rotates about an axis. The switching mechanism 4502 provides an electrical signal to indicate the position of the limit switch 4506. Figure 48 This is a top view showing sleeve 4500 rotated until limit switch 4506 has rotated from its neutral position to its maximum angle (α) orientation. Further rotation of the sleeve causes limit switch 4506 to disengage from actuator arm 4508 and return to its neutral position. This change in orientation of the switch arm indicates the end of rotation of sleeve 4500 in one direction and reverses the rotary metering pump. Figure 49This is a side view oriented toward the sleeve face, showing the same interaction between the limit switch 4506 and the actuator arm 4508. Figure 50 This is a side view showing that the sleeve 4500 and switching mechanism 4502 are integrated into the patch pump together with the interlocking collar 4510.

[0172] Figure 51A The relative angular positions of limit switch 4506 and actuator arm 4508 are shown. α is the angle of limit switch 4506. β is the angle between the rotating sleeve and the actuator arm. Figure 51B The relative changes d(α) / d(β) and β are shown. Preferably, reversal is triggered at β = 33°. As shown, when actuator arm 4608 rotates, it pushes limit switch 4506 away from the neutral position (α = 0°). When the angle β of the actuator arm reaches approximately 30β, actuator arm 4508 avoids limit switch 4506, and limit switch 4506 returns to the neutral position (α = 0°), thereby initiating the reverse rotation of the rotary pump. The same process occurs in reverse when sleeve 4508 rotates in the other direction. Therefore, the sleeve reciprocates back and forth.

[0173] Now combine Figures 52 to 67 The improved plunger and pump plug components are described. As will now be described, the improved plunger 5210 and pump base 5206 improve the pump by making these components easier to manufacture and assemble and by eliminating potential sources of fluid leakage from the existing design. Figures 52 to 58 Multiple views in the image show plunger 5210. Plunger 5210 and... Figure 40 The plunger 4010 shown is basically similar, except that the O-ring 4008 is not required because the seal, which will be described below, is overmolded onto the head 5212 of the plunger 5210.

[0174] exist Figures 59 to 62 Seal 5214 is shown in several views. Seal 5214 is advantageously overmolded onto the head 5212 of plunger 5210. Thus, the plunger with seal is advantageously manufactured using a two-stage injection molding process. Plunger 5210 is molded from a rigid plastic material, and then seal 5214 is molded onto plunger 5210 as a second injection from a viscoelastic elastomer. The combined plunger 5210 and seal 5214 are easier to assemble into the entire pump and reduce the chance of leakage due to O-ring design.

[0175] exist Figures 63 to 67 Pump plug or stopper 5206 is shown. Pump plug 5206 essentially corresponds to Figure 4The plug 4006 is overmolded onto the head 5208 of the pump plug 5206, except that it replaces the O-ring seal 5214 (the same or substantially similar sealing component can be used for the plunger 5210 and pump plug 5206). Similar to the plunger 5210 described above, the pump plug 5206 and the seal 5214 are preferably manufactured using a two-stage injection molding process. The pump plug 5206 is molded from a rigid plastic material, and the seal 5214 is molded onto the pump plug 5206 as a second injection molding material from a viscoelastic elastomer.

[0176] Figure 68 An exploded view of the metering assembly 4000 is shown, but with an improved plunger 5210, pump plug 5206, and seal 5214. Those skilled in the art will understand that, as the plug 4006 is optional in existing designs, it can be... Figure 44 As shown, wall 4404 is used instead, therefore pump plug 5206 is optional and can be replaced with a similar wall.

[0177] Now combine Figure 69 A method 6900 for manufacturing and assembling a pump using the overmolded components described above, according to an exemplary embodiment of the present invention, is described. First, in step 6902, a plunger is molded from rigid 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 within and seal the pump chamber. Optionally, a pump plug is molded from rigid plastic in step 6906, and a seal is overmolded onto the head of the pump plug in step 6908. In step 6910, the plunger and pump plug are inserted into the pump chamber of the pump. In step 6912, a "pin" is inserted into a hole in the plunger so that the plunger can be axially translated when the pump motor rotates the pump chamber.

[0178] Although only some illustrative embodiments of the invention have been described in detail above, those skilled in the art will readily understand that many modifications can be made to the illustrative embodiments and various combinations of the illustrative embodiments are possible without substantially departing from the novel teachings and advantages of the invention. Therefore, all such modifications are intended to be included within the scope of the invention.

Claims

1. A rotary metering pump, the rotary metering pump comprising: A manifold, the manifold including a container port in fluid communication with a fluid container and a cannula port in fluid communication with a cannula; A sleeve including a side hole, the sleeve being adapted to rotate axially within the manifold between a first orientation and a second orientation, wherein in the first orientation the side hole is aligned with the container port and in the second orientation the side hole is aligned with the cannula port, the sleeve further including a helical groove having a first end and a second end; A plunger, the plunger including an overmolded seal molded on a plunger head, the plunger being adapted to rotate and translate axially within a sleeve, wherein the axial translation of the plunger within the sleeve changes a pump volume, the pump volume being in fluid communication with a side hole of the sleeve, the plunger further including a connecting member adapted to move within a helical groove and between a first end and a second end of the helical groove to cause the plunger to translate axially within the sleeve as the plunger rotates; A motor adapted to rotate the plunger in a first direction when the sleeve is in the first orientation, thereby increasing the pump volume, and to rotate the sleeve and the plunger together when the connecting member reaches the first end of the helical groove, thereby moving the sleeve to the second orientation; The rotary metering pump further includes a rotary limit switch that generates an electrical signal that causes the motor to reverse after the sleeve rotates to orient the side hole toward the insertion port. The sleeve includes an actuator arm fixed to the sleeve, the actuator arm moving a limit switch as the sleeve rotates in any direction, and wherein, when the actuator arm rotates past the limit switch, the limit switch is biased to return to the center position.

2. The rotary metering pump according to claim 1, wherein, The plunger further includes a protrusion, and the manifold includes a window, and the protrusion moves within the window to prevent the sleeve from axially translating relative to the manifold when the sleeve rotates within the manifold.

3. The rotary metering pump of claim 1, further comprising a plug, the plug including a seal overmolded onto the head of the plug, the plug being inserted into the sleeve to form a surface of the pump volume opposite to the plunger.

4. The rotary metering pump according to claim 1, wherein, The sleeve includes a face stop that forms a surface of the pump volume opposite to the plunger.

5. The rotary metering pump of claim 3, further comprising seals on the plunger and the plug to form a liquid-tight seal between the plunger and the sleeve and between the plug and the sleeve.

6. The rotary metering pump according to claim 1, wherein, The motor includes an output gear having a groove for receiving a protrusion of the plunger, the groove allowing the plunger to move axially relative to the motor as the motor rotates the plunger.

7. The rotary metering pump of claim 1, further comprising an interlocking element that prevents the sleeve from rotating when the torque applied to the sleeve is below a predetermined threshold, and wherein, When the torque exceeds the predetermined threshold, the interlock allows the sleeve to rotate.

8. The rotary metering pump according to claim 7, wherein, The sleeve includes a ratchet that engages with a protrusion on the interlocking member to prevent the sleeve from rotating, and wherein the interlocking member flexes to allow the ratchet to move over the protrusion on the interlocking member when the torque applied to the sleeve exceeds the predetermined threshold.

9. The rotary metering pump according to claim 1, further comprising at least one port seal forming a liquid-tight seal between the sleeve and the container port.

10. The rotary metering pump according to claim 1, further comprising at least one port seal forming a liquid-tight seal between the sleeve and the insertion port.

11. The rotary metering pump according to claim 9 or 10, wherein, The port seal is a monolithic elastomeric component.

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