JP2025111846A - Rotary metering pump for insulin patch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotational metering pump.

SOLUTION: A rotational metering pump comprises: a sleeve having a side hole, the sleeve adapted to rotate axially within a manifold between a first orientation with the side hole aligned with a reservoir port and a second orientation with the side hole aligned with a cannula port, the sleeve further having a helical groove having a first end and a second end; a motor adapted to rotate a plunger in the second orientation, reducing a pump volume when the sleeve is in the second orientation, and rotating the sleeve and the plunger together when a coupling member reaches the second end of the helical groove, so that the sleeve transitions to the first orientation; and an early rotation prevention function disposed on the manifold, cooperating with the sleeve to prevent rotation of the sleeve when torque applied to the sleeve is less than or equal to a predetermined threshold, and permitting the sleeve to rotate when the torque exceeds the predetermined threshold.

SELECTED DRAWING: Figure 43A

COPYRIGHT: (C)2025,JPO&INPIT

Description

The disclosed invention relates to a metering system for use in a general wearable drug infusion patch.

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

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 their chances of living a complication-free life. However, achieving good diabetes control while balancing other life demands and circumstances is not always easy.

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 generally require three to four injections per day and require puncture for each injection. These devices are simple to use and relatively inexpensive. Another widely applicable and effective method of treatment for managing diabetes is the use of insulin pumps. Insulin pumps more closely mimic the behavior of the pancreas, providing continuous infusion of insulin at varying rates to help users maintain their individual blood glucose levels within target ranges based on their individual needs. Using an insulin pump allows users to tailor their insulin therapy to their individual lifestyle, rather than tailoring their individual lifestyle to how insulin injections work for them.

However, conventional insulin pumps suffer from several drawbacks. For example, the lead screw and piston-type metering systems used in typical insulin pumps require significant height and a large footprint, and are often cumbersome for users.

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

Also, conventional insulin pumps typically have a tolerance loop that is too long for dose accuracy, depending on too many factors that can be difficult to verify. This can result in a loss of dose accuracy.

Additionally, conventional insulin pumps generally have overly complicated fluid paths, which can result in complex or inefficient priming and air removal.

Additionally, conventional insulin pumps generally require high-precision actuators, which increases the cost of conventional patch pumps.

Some insulin pumps also pose a risk of creating a direct fluid path between the reservoir and the cannula in the insulin patch, which can result in the user receiving an overdose.

Additionally, conventional insulin pumps typically require complex sensing methods, which can result in increased costs and reduced accuracy and reliability.

Additionally, conventional insulin pumps typically have valves that are prone to leaking under elevated system back pressure, which can result in reduced accuracy and reliability.

Additionally, conventional insulin pumps typically require large working volumes and large system volumes that are subject to potentially high back pressure, which can result in reduced accuracy and reliability.

Additionally, conventional insulin patches typically have inefficient motors that require large batteries, thereby increasing the size of the insulin patch.

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 increase user comfort.

There is also a need for a metering system that has a reduced number of components and moving parts compared to conventional insulin pumps to increase the mechanical stability of the insulin patch.

There is also a need for a metering system that has a shorter tolerance loop for dose accuracy dependency compared to conventional metering pumps, thereby increasing dose accuracy.

There is also a need for a metering system with a simpler fluid path compared to conventional metering systems, thereby simplifying priming and air removal.

There is also a need for a metering system that utilizes a lower precision actuator compared to conventional metering systems, thereby reducing the cost of insulin patches.

There is also a need for a metering system that does not have a direct fluid path between the reservoir and the cannula, compared to conventional metering systems, thereby providing greater user safety protection from overdose.

There is also a need for a metering system that has a simpler detection scheme compared to conventional metering systems, thereby reducing costs and increasing accuracy and reliability of insulin patches.

There is also a need for a metering system having a valve that is more robust with respect to leakage at elevated system back pressures compared to conventional metering systems, thereby increasing the accuracy and reliability of the insulin patch.

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

There is also a need for a metering system that requires a highly efficient motor with a small battery compared to conventional metering systems, thereby reducing the size of the insulin patch.

One aspect of exemplary embodiments of the invention disclosed herein substantially addresses these and other concerns and provides a small and reliable weighing system.

One aspect of exemplary embodiments of the invention disclosed herein is to provide a metering system with a reduced height and footprint compared to conventional lead screw and piston type metering systems, increasing comfort for the user.

Another aspect of exemplary embodiments of the presently disclosed invention is to provide a metering system with a reduced number of components and moving parts compared to conventional insulin pumps to increase the mechanical stability of the insulin patch.

Another aspect of exemplary embodiments of the presently disclosed invention is that it provides a metering system with a short tolerance loop for dose accuracy that depends on fewer factors compared to conventional metering pumps, thereby increasing dose accuracy. For example, in exemplary embodiments of the presently disclosed invention, the tolerance loop for dose accuracy is short and depends only on two easily measurable dimensions: the diameter of the pump and the axial dimension of the helical slot.

Another aspect of exemplary embodiments of the presently disclosed invention is that it provides a metering system with a simpler fluid path compared to conventional metering systems, thereby simplifying priming and air removal.

Another aspect of exemplary embodiments of the presently disclosed invention is to provide a metering system that utilizes a lower precision actuator compared to conventional metering systems, thereby reducing the cost of the insulin patch. For example, in exemplary embodiments of the presently disclosed invention, the mechanism can over-rotate at both ends of the stroke and still maintain dosage accuracy.

Another aspect of exemplary embodiments of the presently disclosed invention is that, compared to conventional metering systems, the metering system provides a fluid path that does not have a direct fluid path between the reservoir and the cannula, thereby providing greater user safety protection against overdose.

Another aspect of exemplary embodiments of the presently disclosed invention is to provide a metering system with a simpler sensing scheme compared to conventional metering systems, thereby reducing costs and increasing the accuracy and reliability of the insulin patch. For example, in exemplary embodiments of the presently disclosed invention, the sensing scheme is based on a contact switch.

Another aspect of exemplary embodiments of the presently disclosed invention is to provide a metering system that allows the mechanical stroke of the pump to be a simple actuation of the cannulation mechanism.

Another aspect of exemplary embodiments of the presently disclosed invention is to provide a metering system having a valve that is robust with respect to leakage at elevated system back pressure compared to conventional metering systems, thereby increasing the accuracy and reliability of the insulin patch. For example, in exemplary embodiments of the presently disclosed invention, the valve does not have a volume change when transitioning between states.

Another aspect of exemplary embodiments of the presently disclosed invention is to provide a metering system that has a small working volume and a low system volume exposed to potentially high back pressure compared to conventional metering systems, thereby increasing the accuracy and reliability of the insulin patch.

Another aspect of exemplary embodiments of the presently disclosed invention is to provide a metering system that uses a high-efficiency motor with a smaller battery compared to conventional metering systems, thereby reducing the size of the insulin patch.

These and/or other aspects of the presently disclosed invention are accomplished by providing a metering system for use in a wearable insulin infusion patch. For example, in an exemplary embodiment of the presently disclosed 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 into the patient. The fluid dose is small relative to the reservoir volume, such that many pump strokes are required to completely empty the reservoir.

Additional and/or other aspects and advantages of the presently disclosed invention will be set forth in the description that follows, or will be obvious from the description, or may be learned by practice of the invention. The presently disclosed invention may comprise a method, apparatus, or system having one or more of the above-described aspects and/or one or more of the features and combinations thereof. The presently disclosed invention may comprise one or more of the features and/or combinations of the above-described aspects, for example, as set forth in the accompanying claims.

Various objects, advantages and novel features of the illustrative embodiments of the present invention will be more readily understood from the following detailed description when read in conjunction with the accompanying drawings.
1A-1D illustrate the structure of an exemplary embodiment of an inventive patch pump according to the present disclosure. FIG. 1 illustrates the layout of fluid and metering system components of an exemplary embodiment of an inventive patch pump according to the present disclosure. FIG. 1 is a schematic exploded view of a metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure. FIG. 1 illustrates the layout of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure. 1 is a schematic cross-sectional view of a metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure. FIG. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in a starting position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in a starting position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during an intake stroke. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during an intake stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an intake stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an intake stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an intake stroke. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in an inspiration transition stop position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in an inspiratory transition stop position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during an ejection stroke. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during an ejection stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an exhaust stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an exhaust stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an exhaust stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure after a pump cycle is completed. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure after a pump cycle is completed. FIG. 1 is an exploded view of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure. 1 is a schematic exploded view of a pump assembly of an exemplary embodiment of an inventive metering pump according to the present disclosure; FIG. FIG. 1 is a schematic exploded view of a motor and gearbox assembly of an exemplary embodiment of an inventive metering pump according to the present disclosure. 10A-10C are several schematic diagrams illustrating how the piston is assembled into the sleeve in accordance with the present disclosure; 10A-10C are several schematic diagrams illustrating how the piston is assembled into the sleeve in accordance with the present disclosure; 10A-10C are several schematic diagrams illustrating how the piston is assembled into the sleeve in accordance with the present disclosure; 10A-10C are several schematic diagrams illustrating how the piston is assembled into the sleeve in accordance with the present disclosure; 10A-10C are several schematic diagrams illustrating a method of assembling a plug into a sleeve in accordance with the present disclosure. 10A-10C are several schematic diagrams illustrating a method of assembling a plug into a sleeve in accordance with the present disclosure. 10A-10C are several schematic diagrams illustrating a method of assembling a plug into a sleeve in accordance with the present disclosure. 10A-10C are several schematic diagrams illustrating how a sleeve may be incorporated into a manifold in accordance with the present disclosure. 10A-10C are several schematic diagrams illustrating how a sleeve may be incorporated into a manifold in accordance with the present disclosure. 10A-10C are several schematic diagrams illustrating how a sleeve may be incorporated into a manifold in accordance with the present disclosure. 10A-10C are several schematic diagrams illustrating how a sleeve may be incorporated into a manifold in accordance with the present disclosure. 1 is a schematic cross-sectional view of a pump assembly of an exemplary embodiment of an inventive patch pump according to the present disclosure. FIG. 1A-1C are a number of schematic cross-sectional views illustrating an inventive method for changing valve states according to the present disclosure. 1A-1C are a number of schematic cross-sectional views illustrating an inventive method for changing valve states according to the present disclosure. 1A-1C are a number of schematic cross-sectional views illustrating an inventive method for changing valve states according to the present disclosure. 1A-1C are a number of schematic cross-sectional views illustrating an inventive method for changing valve states according to the present disclosure. 1A-1C are a number of schematic cross-sectional views illustrating an inventive method for changing valve states according to the present disclosure. 10A-10C illustrate multiple views of limit switches for pump and sleeve rotation in the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure. 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 in accordance with the present disclosure. 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 in accordance with the present disclosure. 10A-10C are a number of schematic cross-sectional views illustrating how an inventive pump according to the present disclosure can be incorporated into a gearbox. 1 is a schematic cross-sectional view illustrating how an inventive pump according to the present disclosure can be incorporated into a gearbox; 1 is a schematic cross-sectional view illustrating how an inventive pump according to the present disclosure can be incorporated into a gearbox; 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in a starting position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in a starting position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in a starting position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during an ejection stroke. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during an ejection stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an exhaust stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an exhaust stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during valve state change after an exhaust stroke. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in an ejection rotation stop position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in an ejection rotation stop position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during an intake stroke. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of a patch pump in accordance with the present disclosure during an intake stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure during valve state change after an intake stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure during valve state change after an intake stroke. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure during valve state change after an intake stroke. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in an inhalation rotation stop position. 1A-1C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure in an inhalation rotation stop position. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure after a pump cycle is completed. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure after a pump cycle is completed. 10A-10C are multiple views of the metering subsystem of an exemplary embodiment of an inventive patch pump according to the present disclosure after a pump cycle is completed. 1A-1C are multiple views of an exemplary embodiment of a motor and gearbox assembly of an inventive metering pump according to the present disclosure, and a modified pump assembly; 1A-1C are multiple views of an exemplary embodiment of a motor and gearbox assembly of an inventive metering pump according to the present disclosure, and a modified pump assembly; 1A-1C are multiple views of an exemplary embodiment of a motor and gearbox assembly of an inventive metering pump according to the present disclosure, and a modified pump assembly; FIG. 1 is an exploded view of a pump assembly of an exemplary embodiment of an inventive metering assembly according to the present disclosure. 10A-10C illustrate an exemplary embodiment of an inventive patch pump according to the present disclosure, illustrating assembly of the piston within the sleeve. 10A-10C illustrate an exemplary embodiment of an inventive patch pump according to the present disclosure, illustrating assembly of the piston within the sleeve. 10A-10C illustrate the assembly of a sleeve into a manifold of an exemplary embodiment of an inventive patch pump according to the present disclosure. 10A-10C illustrate the assembly of a sleeve into a manifold of an exemplary embodiment of an inventive patch pump according to the present disclosure. 10A-10C illustrate the assembly of a sleeve into a manifold of an exemplary embodiment of an inventive patch pump according to the present disclosure. 10A-10C illustrate the assembly of a sleeve into a manifold of an exemplary embodiment of an inventive patch pump according to the present disclosure. 10A-10C illustrate the assembly of a sleeve into a manifold of an exemplary embodiment of an inventive patch pump according to the present disclosure. 1A and 1B show cross-sections of a sleeve and manifold assembly of an exemplary embodiment of an inventive patch pump according to the present disclosure. 10A-10C show multiple cross-sections illustrating the valve state changes of an exemplary embodiment of an inventive patch pump according to the present disclosure as the sleeve rotates. 10A-10C show multiple cross-sections illustrating the valve state changes of an exemplary embodiment of an inventive patch pump according to the present disclosure as the sleeve rotates. 10A-10C show multiple cross-sections illustrating the valve state changes of an exemplary embodiment of an inventive patch pump according to the present disclosure as the sleeve rotates. 10A-10C illustrate sleeve rotation limit switches of an exemplary embodiment of an inventive patch pump according to the present disclosure. 10A-10C illustrate sleeve rotation limit switches of an exemplary embodiment of an inventive patch pump according to the present disclosure. 10A-10C illustrate sleeve rotation limit switches of an exemplary embodiment of an inventive patch pump according to the present disclosure. 10A-10C illustrate sleeve rotation limit switches of an exemplary embodiment of an inventive patch pump according to the present disclosure. 1 is an exploded view of a pump assembly of an exemplary embodiment of a patch pump according to the present disclosure, with elastomeric ports and piston seals overmolded onto the manifold and pump piston, respectively. FIG. 1 is an exploded view of a pump assembly of an exemplary embodiment of a patch pump according to the present disclosure, with elastomeric ports and piston seals overmolded onto the manifold and pump piston, respectively. FIG. 1 is an exploded view of a pump assembly of an exemplary embodiment of an inventive patch pump according to the present disclosure, having an alternative rotational limit switch design. FIG. 1 is an exploded view of a pump assembly of an exemplary embodiment of an inventive patch pump according to the present disclosure, having an alternative rotational limit switch design. FIG. 1 is an exploded view of a pump assembly of an exemplary embodiment of an inventive patch pump according to the present disclosure, having an alternative rotational limit switch design. FIG. 1 is an exploded view of a pump assembly of an exemplary embodiment of an inventive patch pump according to the present disclosure, having an alternative rotational limit switch design. FIG. FIG. 1 is an exploded view of an exemplary embodiment of an inventive metering assembly according to the present disclosure. FIG. 41 is an assembled view of the weighing assembly of FIG. 40. FIG. 41 shows a cross section of the weighing assembly of FIG. 40. 41 is a diagram of an exemplary embodiment illustrating the interaction of the sleeve and interlock of the weighing assembly of FIG. 40 in accordance with the present disclosure; FIG. 41 is a diagram of an exemplary embodiment illustrating the interaction of the sleeve and interlock of the weighing assembly of FIG. 40 in accordance with the present disclosure; FIG. 41 is a diagram of an exemplary embodiment illustrating the interaction of the sleeve and interlock of the weighing assembly of FIG. 40 in accordance with the present disclosure; FIG. FIG. 10 illustrates a cross-section of another exemplary embodiment of an inventive metering assembly according to the present disclosure. FIG. 10 is an isometric view of a limit switch and actuator arm useful in an alternative exemplary embodiment of the present disclosure; FIG. 46 is an isometric view of the limit switch and rotating sleeve according to the embodiment of FIG. FIG. 46 is a top view of the limit switch of FIG. 45; FIG. 46 is a top view of the limit switch and actuator arm of FIG. FIG. 47 is an end view of the rotating sleeve of FIG. 46; FIG. 46 is a cross-sectional elevation view of the limit switch and actuator arm of FIG. 10 is a diagram illustrating the relative displacement of a limit switch and a rotating sleeve in accordance with an exemplary embodiment of the present invention. 10 is a diagram illustrating the relative displacement of a limit switch and a rotating sleeve in accordance with an exemplary embodiment of the present invention. 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. 10A-10C are different perspective views of an improved plunger for a pump according to another exemplary embodiment of the present invention. 59 is a different perspective view of an overmolded seal for the improved plunger of FIGS. 52-58. FIG. 59 is a different perspective view of an overmolded seal for the improved plunger of FIGS. 52-58. FIG. 59 is a different perspective view of an overmolded seal for the improved plunger of FIGS. 52-58. FIG. 59 is a different perspective view of an overmolded seal for the improved plunger of FIGS. 52-58. FIG. 10A-10C are different perspective views of the improved pump plug. 10A-10C are different perspective views of the improved pump plug. 10A-10C are different perspective views of the improved pump plug. 10A-10C are different perspective views of the improved pump plug. 10A-10C are different perspective views of the improved pump plug. FIG. 1 is an exploded view of a pump system utilizing an improved plunger, plug, and overmolded seal of an exemplary embodiment of the present invention. 4 is a flowchart of a method for manufacturing a pump according to an exemplary embodiment of the present invention.

It should be understood that like reference numbers refer to like elements, features, and structures throughout the drawings.

As will be appreciated by those skilled in the art, there are many ways to implement examples, modifications, and configurations of a weighing system in accordance with the disclosed embodiments of the invention. While 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 and combinations may be made without departing from the invention.

A variety of individuals, including but not limited to a patient or healthcare professional, may operate or use the exemplary embodiments of the invention disclosed herein, but for simplicity, the operator or user will hereafter be referred to as the "user."

Although various fluids may be used in exemplary embodiments of the invention disclosed herein, for simplicity, the liquid within the injection device will hereafter be referred to as the "fluid."

An exemplary embodiment of the presently disclosed invention is depicted in Figures 1-30. In an exemplary embodiment of the presently disclosed invention, a metering system for use in a wearable insulin infusion patch is provided. For example, in an exemplary embodiment of the presently disclosed 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 the subcutaneous tissue. The metering system draws a small amount of fluid from the reservoir and then pushes it down the cannula line into the patient. The fluid dose is small relative to the reservoir volume, such that many pump strokes are required to completely empty the reservoir.

FIG. 1 shows the structure of a patch pump 100 according to an exemplary embodiment of the present disclosure. The patch pump 100 includes a fluidics subsystem 120, an electronics subsystem 140, and a power storage subsystem 160.

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.

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.

The fluidics subsystem 120 further 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 reservoir 124 of the fluidics subsystem 120 and is actuated by the pump and valve actuator 134.

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.

The fluidics subsystem 120 further includes an occlusion sensor 136 mechanically coupled to the fluid path between the cannula 129 and the integrated pump and valve system 132. The occlusion sensor 136 is adapted to detect or determine an occlusion in the path between the cannula 129 and the integrated pump and valve system 132.

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 130, 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.

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

FIG. 2 illustrates the layout of fluid and metering system components of a patch pump 200 in accordance with an exemplary embodiment of the present disclosure. The 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 the patch pump 200 are substantially similar to, and interact in a substantially similar manner with, elements of the exemplary patch pump 100 referenced by like reference numbers.

Figure 3 is an exploded perspective view of a metering subsystem 300 of a patch pump in accordance with an exemplary embodiment of the present disclosure. 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 also includes a port seal 314 on a seal carriage 316 disposed within a valve housing 318.

In an exemplary embodiment of the invention according to the present disclosure, the DC gear motor output shaft 320 can rotate 360 degrees in either direction. The pump piston 304 can rotate 360 degrees in either direction and translate approximately 0.050 inches. The pump housing 308 can rotate 180 degrees in either direction. The pump casing 306, port seal 314, seal carriage 316, and valve housing 318 are preferably stationary.

The metering subsystem 300 includes a positive displacement pump with an integrated flow control valve and mechanical actuator and drive system. The pump includes a piston 304 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) and then expels this insulin volume through a cannula into the patient's subcutaneous tissue, administering small, discrete doses of insulin. The pump stroke creates positive and negative pressure gradients in the fluid path, inducing 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 fluid port at each end of the pump stroke, alternately closing and opening the port to ensure unidirectional fluid flow (from the reservoir to the patient) and no free flow between the reservoir and the patient.

Figure 4 is an assembly view of the metering subsystem 300 according to an exemplary embodiment of the present disclosure. Also shown are the motor-to-piston connection 322, the piston-to-pump housing connection 324, the reservoir port 326, and the cannula port 328.

Figure 5 is a cross-sectional view of the metering subsystem 300 of an exemplary embodiment of the present disclosure. As shown, a pump volume 320 is defined between the piston and the pump housing 308. The pump housing includes a side port 330 that alternates in orientation between the reservoir port 326 and the cannula port 328 as the motor 302 reciprocates the pump, as described in more detail below.

During operation, an exemplary cycle of the inventive metering system according to the present disclosure includes four steps: 180 degree pump intake (counterclockwise) (looking from the pump towards the motor), 180 degree valve state change (counterclockwise), 180 degree pump exhaust (clockwise), and 180 degree valve state change (clockwise). A complete cycle requires a full rotation (360 degrees) in each direction.

6A is an isometric view, and FIG. 6B is a cross-sectional view of the metering subsystem 300 in the start position. In the start position, the pump piston 302 is fully extended, the pump housing closes the cannula port flow path at the cannula port 328, the reservoir port 326 opens to the side port 330 of 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 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, axially translating the piston 304 relative to the pump housing 308. In this embodiment, the helical groove 334 is formed in the pump housing 308 and provides 180 degrees of rotation for the coupling pin 310.

Figure 7A is an isometric view, and Figure 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 spiral 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.

8A is an assembly view, FIG. 8B is a detailed view, and FIG. 8C is a cross-sectional view of the patch pump during a valve state change after the intake stroke. Torque is transmitted from the drive shaft of the motor 302 to the pump piston 304 and through the coupling pin 310 to the pump housing 308. When 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. The pump housing side port 330 transitions out of alignment with the reservoir port 326 and into alignment with the cannula port 328 over the next 180-degree rotation of the motor 302. Meanwhile, both the cannula port 328 and the reservoir port 326 are closed. The coupling pin 310, at the end of the helical groove 334, 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 one another. 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.

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 inject. 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.

Figure 10A is an assembly view, and Figure 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 engages the limit switch 332, which switches 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, forcing fluid from the pump volume 320 through the cannula port 328 and into the cannula. During the exhaust 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 remains stationary while the pump volume 320 collapses, and the pump piston 304 rotates and translates in a spiral motion. A motor is slidably connected to the piston 304 and accommodates the translational movement of the piston as it rotates within the spiral groove 334.

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, and 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.

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.

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 communicating with the pump volume transitions from alignment with the reservoir port to alignment with the cannula port.

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

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 atmospheric seals and seal the pump and valve system during a state change.

In the exemplary embodiment described above, a DC gear motor is used to drive the pump and valves. However, in other embodiments, any suitable drive mechanism may be provided to drive the pump and valves. For example, a solenoid, nitinol wire, voice coil actuator, piezo motor, wax motor, and/or any other type of motor known in the art may be used to drive the pump.

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 an increasingly larger ejection stroke may be used to administer finer doses.

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 capable of determining intermediate states, such as encoder wheels or optical sensors, may be used to improve the resolution of the sensing scheme.

It should be understood that the pump bore may be adjusted to vary the nominal output per cycle.

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.

In an alternative embodiment of the present invention, pump movement may be used to trigger or initiate cannula deployment.

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 dispense medication from the reservoir. However, it should be understood that in other embodiments, the metering system may be designed to use a unidirectional actuator.

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

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

Figure 14 is an exploded perspective view of pump assembly 1304. Pump assembly 1304 includes a piston 1306 mechanically coupled to a sleeve 1308 via a coupling pin 1310 within a pump manifold 1312. 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.

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

Figure 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.

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, and the coupling pin 1310 is then press-fit into the bore 1338 through the helical groove 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 preferably provided at the end of the spiral groove 1342 to center the coupling pin 1310 within the groove 1342.

FIG. 17A illustrates the assembly of the plug 1316 and sleeve 1308. As shown, the plug 1316 includes a key 1346 and a seal 1348. The seal 1348 provides an interference fit for the plug within the sleeve 1308. The sleeve 1308 is provided with a recess 1350 adapted to receive the key 1346. The key 1346 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 pressure greater than a threshold value causes 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 with 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 maximum pumping 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.

Figures 18A-18D illustrate the assembly of the sleeve 1308 to the manifold 1312. As shown in Figure 18A, the manifold 1312 includes port seals 1314 to seal the reservoir port 1354 and the 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 degrees apart. As shown in Figure 18B, the sleeve 1308 includes tabs 1360, and the manifold 1312 includes corresponding slots 1362 to allow the sleeve 1308 to be assembled to the manifold 1312. Figure 18C illustrates a manifold window 1364 provided in the manifold. The tabs 1360 are received and translated into the windows 1364 when the sleeve 1308 is assembled to the manifold 1312. Tab 1360 and aperture 1364 interact to permit rotation of sleeve 1308 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. FIG. 18D illustrates sleeve 1308 assembled to manifold 1312 with tab 1360 positioned within manifold aperture 1364.

Figure 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 within 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.

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 further rotated 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.

Figures 21A-21C illustrate the operation of the limit switch. As shown in Figure 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 Figure 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, the 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 rotation of 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.

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-fit onto the motor and gearbox 1302. The motor and gearbox 1302 includes a rotation key 1376 in a pump receiving socket 1378 to receive the pump assembly 1304 and restrain rotation of the pump assembly 1304 relative to the motor and gearbox 1302. The output gear 1326 includes slots 1380 (FIG. 22B) adapted to receive tabs 1382 (FIG. 22C) provided on the piston 1306. When assembled, the tabs 1382 are received in the slots 1380 so that the output gear 1326 can transmit torque to the piston 1306. As the output gear 1326 rotates, the 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.

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

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

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 so that the flexures are not touching each other. The pump piston 1306 is retracted, as indicated by the position of the coupling pin 1310 within 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 of the sleeve 1308, and both the rotation limit sensor 1320 and the sleeve sensor 1318 (see Figure 23B) are open.

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 along the helical path of the spiral groove 1342 in the sleeve 1308 via the coupling pin 1310 (see Figure 24A). 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.

FIGS. 25A-25C illustrate the metering subsystem during a valve state change after the discharge stroke. As shown in FIG. 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 and through the coupling pin 1310 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 FIGS. 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 FIG. 25B, the sleeve limit switch 1318 is closed by the cam surface of the plug 1316.

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, preventing the output gear 1326 from rotating backward.

Figures 27A and 27B show the metering subsystem during the intake stroke. The output gear 1326 rotates the pump piston 1306 in the direction indicated by the arrow in Figure 27B. The piston 1306 is translated axially relative to the sleeve 1308 due to the interaction of the coupling pin 1310 in the helical groove 1364. The pump piston 1306 translates toward the gearbox, drawing fluid from the reservoir into the pump chamber 1352. During the intake stroke, friction between the seal and the outer diameter of the sleeve 1308 is desirably high enough to ensure that the sleeve 1308 does not rotate relative to the manifold 1312.

Figures 28A-28C show the metering subsystem during a valve state change after the intake stroke. The coupling pin 1310 reaches the top of the spiral groove 1342, and the motor 1302 continues to provide torque, rotating the sleeve 1308 and piston 1306 together. The tab 1360 on the sleeve 1308 transitions within the window 1364 in the manifold 1312 in the direction indicated by the arrow in Figure 28A. The 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.

Figures 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 on the output gear 1326 engages the rotation limit switch 1320, signaling that rotation is complete. The motor 1302 stops reverse rotation. The sleeve limit switch 1318 is open.

Figures 30A-30C show the metering subsystem after a pump cycle is completed. The output gear cam 1366 has gently rocked away from the rotary switch 1320, ready to begin another cycle.

Figures 31A-31C illustrate another metering system 3100a in accordance with an exemplary embodiment of the present disclosure. Figure 31A shows a motor and gearbox assembly 3101 and a modified 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.

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

The pump assembly 3100 includes three bent arms 3128 that operate as rotational translation limit switches 3114, which are 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.

Figures 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.

Figures 34A-34E illustrate the assembly of the sleeve 3108 onto the manifold 3102. As shown, the port seal 3104, seal retainer 3106, and sleeve 3112 are inserted into the manifold 3102. Small side holes 3115 (see Figure 34E) on the sleeve 3112 rotate back and forth between the reservoir port and the cannula port, which are preferably 56 degrees apart. The sleeve 3112 is inserted over retention tabs 3116 (see Figure 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.

FIG. 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.

Figures 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 Figure 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 Figure 36B, the sleeve side hole 3115 is closed by the port seal 3104 during the transition. In the final position shown in Figure 36C, the sleeve side hole 3115 is open to the cannula port 3118. In this position, the reservoir port 3120 is closed.

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.

The pump described above has a modified operating sequence. The operating sequence is substantially the same as described above, except that the 20 degree back jiggle is no longer required. The back jiggle is not required with the three-point contact switch design described above, and the complete pump cycle consists of four segments: First, there is approximately 140 degrees of pump discharge, which is counterclockwise when looking from the pump toward the gearbox. Next, there is a 56 degree valve state change, also counterclockwise. Third, there is a 140 degree pump intake, which is clockwise. Fourth, there is a 56 degree valve state change, clockwise. This total pump cycle requires 196 degrees of output gear rotation in each direction.

Figures 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 dimensions contributing to seal compression, allowing for less variability and tighter control of sealing performance.

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, leaving the contact switch 3902 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 open because it is midway between the ports and 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.

FIG. 40 is an exploded perspective view of another exemplary embodiment of a metering assembly 4000. This embodiment is substantially similar to the embodiment described above, 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 packaged form. The seals 4008 are preferably formed of an elastomeric material and are 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 projects 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.

Figures 43A-43C illustrate the interaction of the interlock 4018 and the sleeve 4002. As shown in Figure 41, the interlock 4018 is attached to the manifold 4014 at either end of the interlock 4018. As shown in Figure 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, friction between the piston 4010 and sleeve 4008 could be sufficient to rotate the sleeve before the plunger 4010 and coupling pin 4012 reach either end of the spiral groove 4004. This 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 ensures that the piston 4010 rotates fully within the sleeve 4008 until the coupling pin 4012 reaches the end of the spiral groove 4004. 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 be passed by the ridge 4022. This is shown in FIG. 43B. Upon completion of rotation of the sleeve 4008 such that the side hole is oriented with the cannula port, the detent 4020 transitions past the ridge 4022 in the interlock 4018. This is shown in FIG. 43C.

Figure 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.

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 the limit switch 4506 rotating 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 illustrating 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 the actuator arm 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, causing the rotary metering pump to rotate in the opposite direction. 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, along with an interlock collar 4510.

Figure 51A illustrates the relative angular position of the limit switch 4506 and actuator arm 4508. α is the angle of the limit switch 4506. β is the angle of the rotating sleeve and actuating arm. Figure 51B illustrates the relative change d(α)/d(β) versus β. Reverse rotation is preferably initiated at β = 33 degrees. As shown, as the actuating arm 4508 rotates, it pushes the limit switch 4506 away from the neutral position (α = 0 degrees). When the actuating arm angle β reaches approximately 30β, the actuating arm 4508 clears the limit switch 4506, and the limit switch 4506 returns to neutral (α = 0 degrees), thereby initiating reverse rotation of the rotary pump. When the sleeve 4508 rotates in the other direction, the same sequence occurs in reverse. Thus, the sleeve reciprocates back and forth.

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 base 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.

The seal 5214 is shown in multiple views in FIGS. 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 reduces the chance of leakage presented by the O-ring design.

A pump stopper or plug 5206 is illustrated 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 as a second shot from a viscoelastic elastomer.

FIG. 68 illustrates an exploded view of the metering assembly 4000, including the improved plunger 5210, stopper 5206, and seal 5214. Those skilled in the art will understand that just as the plug 4006 was optional in the prior design 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.

A method 6900 for manufacturing and assembling a pump according to an exemplary embodiment of the present invention utilizing the above-described overmolded components 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 seal properly 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. The plunger and pump stopper are inserted into the pump chamber of the pump in step 6910. 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 (step 6912).

Although only a few exemplary embodiments of the invention according to the present disclosure have been described in detail above, 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. Accordingly, all such modifications are intended to be included within the scope of the present invention.

Claims (11)

a manifold having a reservoir port in fluid communication with the fluid reservoir and a cannula port in fluid communication with the cannula;
a sleeve having a side hole adapted for axial rotation within the manifold between a first orientation in which the side hole is aligned with the reservoir port and a second orientation in which the side hole is aligned with the cannula port, the sleeve further having a spiral groove having a first end and a second end;
a plunger having an overmolded seal molded over a plunger head, the plunger adapted for rotation and axial translation 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 adapted to transition within the spiral groove between a first end and a second end of the spiral groove, and further comprising a coupling member for axially translating the plunger within the sleeve as the plunger is rotated;
a motor adapted to rotate the plunger in the first orientation, increasing the pump volume when the sleeve is in the first orientation, and rotating the sleeve and the plunger together when the coupling member reaches the first end of the spiral groove, causing the sleeve to transition to the second orientation;
the motor is adapted to rotate the plunger in the second orientation, decrease the pump volume when the sleeve is in the second orientation, and rotate the sleeve and the plunger together when the coupling member reaches the second end of the spiral groove, causing the sleeve to transition to the first orientation;
a pre-rotation prevention feature disposed on the manifold and cooperating with the sleeve to prevent rotation of the sleeve when a torque applied to the sleeve is below a predetermined threshold, and to allow rotation of the sleeve when the torque exceeds the predetermined threshold. The rotary metering pump of claim 1, wherein the sleeve includes a detent that engages a raised portion of the bump of the anti-premature rotation feature to prevent rotation of the sleeve until torque applied to the sleeve exceeds a predetermined threshold. The rotary metering pump of claim 1, further comprising a rotation limit switch that reverses rotation of the motor when the coupling member reaches either the first end or the second end of the spiral groove after the sleeve has rotated. The rotary metering pump of claim 1, further comprising a rotation limit switch, wherein the sleeve comprises a sleeve rotation limit feature configured to contact the rotation limit switch to determine a direction for reversing the direction of the motor. The rotary metering pump of claim 1, wherein the plunger further includes a tab, the manifold includes a window, and the tab transitions within the window to restrain the sleeve from axially translating relative to the manifold as the sleeve rotates within the manifold. The rotary metering pump of claim 1, further comprising a plug inserted into the sleeve and forming a surface of the pump volume facing the plunger. The rotary metering pump of claim 1, wherein the sleeve has a face stop that forms a surface of the pump volume facing the plunger. The rotary metering pump of claim 6, further comprising seals on the plunger and the plug to form a fluid-tight seal between the plunger and the plug, and between the plug and the sleeve. The rotary metering pump of claim 1, wherein the motor has an output gear with slots for receiving tabs on the plunger, the slots allowing the plunger to translate axially relative to the motor while the motor rotates the plunger. The rotary metering pump of claim 1, further comprising at least one port seal forming a fluid-tight seal between the sleeve and the reservoir port. The rotary metering pump of claim 10, wherein the port seal is a one-piece elastomeric member.