Patent Description:
Healthcare providers may prescribe patients wearable devices for delivering fluids, such as liquid medicaments, as part of a treatment regimen. Non-limiting examples of medicaments may include chemotherapy drugs, hormones (for instance, insulin), pain relief medications, and other types of liquid-based drugs. In general, wearable medicament delivery devices are relatively small form factors that may be adhered to the skin of the patient, with a reservoir to hold the medicament. The device may include a needle or cannula fluidically coupled to the reservoir and extending from the device and into the skin of the patient. A pump may operate to force the fluid from the reservoir, through a fluid path, and out through the needle and into the patient (as e.g. disclosed in <CIT>). A control system, with hardware and/or software elements, may be arranged within the device to manage medicament delivery and other device features. The control system may operate alone or in combination with an external computing device, such as a patient smartphone, healthcare provider computer, and/or the like.

Minimizing the footprint of a wearable medicament delivery device makes the device less obtrusive to the patient and improves the overall user experience. Accordingly, developers are consistently under pressure to reduce the size of operating components, while increasing the features (for example, monitoring patient physiological information, increasing automation, and/or the like) while limiting power demands. In order to achieve a smaller and more compact device, components are required to be smaller and more compact. For example, current pumping mechanisms include a valve switch to allow a user to fill the reservoir and to dispense a medicament. The valve must be shut while the user fills the reservoir, and open when the pump begins working. The valve must also differentiate between filling and dispensing of the pump. This entails three states for the valve, for example, closed, open for filling, and open for dispensing. Accordingly, conventional pump systems are not able to efficiently and effectively manage fluid flow within a device while meeting the space and energy demands of devices that are desired by patients.

Therefore, there is a need for an improved pumping mechanism for a wearable medicament delivery device that can be made compact and energy efficient while achieving a desired dosage accuracy.

The present invention is directed to a fluid pump system for a wearable fluid delivery device as defined in claim <NUM>.

In some embodiments of the fluid pump system, the wearable fluid delivery device may be configured to deliver a medicament to a patient, the medicament comprising insulin. In some embodiments of the fluid pump, the movable portion may include a bistable mechanism.

In exemplary embodiments of the fluid pump system, the state of the fluid path may include one of a fluid delivery state to deliver the fluid to the patient from the pump chamber or a fluid fill state to fill the pump chamber from a reservoir in fluid communication with the fluid path.

In various embodiments of the fluid pump system, the actuator may include a shape memory alloy. In some embodiments of the fluid pump, the offset may include a substantially triangular projection extending from the movable portion. In various embodiments of the fluid pump system, the fluid pump may include a spring configured to bias the shaft in a direction toward the movable portion in the absence of the force of the actuator. In exemplary embodiments of the fluid pump system, the shaft may include a detent arm.

In some embodiments of the fluid pump system, the movable portion may be associated with a first magnet attracted to a portion of the fixed portion to maintain the movable portion in contact with the fixed portion on a closed side of the fluid path valve until the shaft engages the movable portion to pivot the movable portion. In various embodiments of the fluid pump system, the V-feature may include at least one channel for shaft to travel during operation of the fluid path valve. In some embodiments of the fluid pump system, the at least one channel may include a sloped channel with at least one drop-off element to prevent the shaft from engaging an inner wall of the movable portion when traveling toward a central V-section of the V-feature.

The drawings are merely representations, not intended to portray specific parameters of the disclosure. The drawings are intended to depict example embodiments of the disclosure, and therefore should not be considered as limiting in scope. In the drawings, like numbering represents like elements.

The described technology generally relates to a wearable fluid delivery device for delivering a fluid to a patient. In some embodiments, the fluid may be or may include a medicament. The wearable fluid delivery device may include a reservoir for holding the fluid, a fluid path in fluid communication with the reservoir, a needle in fluid communication with the fluid path to deliver the fluid to the patient wearing the wearable fluid delivery device, and a fluid delivery pump configured to force the fluid from the reservoir, through the fluid delivery path, and into the patient via the needle.

In some embodiments, a fluid path valve or switch may be within, or in fluid communication with, the fluid path. The fluid path valve may be configured to alternate between multiple states or positions to configure the flow of the fluid through the fluid path. For example, operation of the fluid delivery pump may be configured to alternate between filling a pump chamber with fluid from the reservoir and pumping the fluid from the pump chamber into the patient. The fluid path valve may be set into a first state for filling the pump chamber and a second state to allow operation of the pump to move the fluid from the pump chamber and into the patient. In various embodiments, the fluid path valve may be a bistable valve having two stable positions. In exemplary embodiments, the fluid path valve may be or may include a "push-push" mechanism configured to actuate between at least two states. In various embodiments, the fluid path valve may be or may include a bistable push-push mechanism. In general, bistable push-push mechanism may enter two possible states, alternating between each state with each "push" or actuation. For example, a bistable push-push mechanism may enter a first state responsive to a first actuation, a second actuation may cause the bistable push-push mechanism to enter a second state, a third actuation may cause the bistable push-push mechanism to re-enter the first state, a fourth actuation may cause the bistable push-push mechanism to re-enter the second state, and so on.

In a conventional fluid delivery device, a pump, such as a reciprocating pump, may require a fluid path that alternates between filling a pump chamber with fluid from a reservoir, and pumping fluid from the chamber into the patient. One example technique to accomplish this is by incorporating an independent actuator to alternate the system between these two states, which would decrease the required load on the pumping actuators. A shape-memory alloy (SMA) wire or other actuator may be used to drive the system; however, one actuator is only able to control one direction of movement in the system, which would be ineffective or greatly increase energy consumption if the actuator needed to hold the fluid path in one position.

Accordingly, a mechanism to reliably alternate between two or more positions is required. In some embodiments, for example, a detent (or detent arm, arm, rod, shaft, pin, rod, push-push element, and/or the like) actuated by an actuator (for example, via an SMA wire and/or a spring) may be placed inside a fluid pathway (for instance, as a fluid pathway valve) that can alternate between two configurations, and attaching them to the needle in the pump, the system may reliably rest in two positions (for instance, a fluid fill state and a fluid delivery state). In some embodiments, the general shape of the path may be or may substantially be a "V" shape, for example, where the inside will be attached to a bistable mechanism that is fixed at the center (see, for example, <FIG> and <FIG>). In various embodiments, an inner corner of the wall of the path may be offset from the outer corner, which may change based on the configuration of the bistable mechanism. By offsetting the corner of the inner wall, the detent may reliably move to one side of the V-shaped path. The configuration of the bistability may be altered when the detent contacts it and causes it to deflect at each of the top points of the V-shaped path (see, for example, <FIG>).

<FIG> illustrates an example of an operating environment <NUM> that may be representative of some embodiments. As shown in <FIG>, operating environment <NUM> may include a fluid delivery system <NUM>. In various embodiments, fluid delivery system <NUM> may include a control or computing device <NUM> that, in some embodiments, may be communicatively coupled to a fluid delivery device <NUM>. Computing device <NUM> may be or may include one or more logic devices, including, without limitation, a server computer, a client computing device, a personal computer (PC), a workstation, a laptop, a notebook computer, a smart phone, a tablet computing device, a personal diabetes management (PDM) device, and/or the like. Embodiments are not limited in this context.

Fluid delivery device <NUM> may be or may include a wearable automatic fluid delivery device directly coupled to patient <NUM>, for example, directly attached to the skin of the user via an adhesive and/or other attachment component.

In some embodiments, fluid delivery device <NUM> may be or may include a medicament delivery device configured to deliver a liquid medicament, drug, therapeutic agent, or other medical fluid to a patient. Non-limiting examples of medicaments may include insulin, GLP-<NUM>, pramlintide, glucagon, pain relief drugs, hormones, blood pressure medicines, morphine, methadone, chemotherapy drugs, proteins, antibodies, a co-formulation of more than one of the foregoing, and/or the like.

In some embodiments, fluid delivery device <NUM> may be or may include an automatic insulin delivery (AID) device configured to deliver insulin (and/or other medication) to patient <NUM>. For example, fluid delivery device <NUM> may be or may include a device the same or similar to an OmniPod® device or system provided by Insulet Corporation of Acton, Massachusetts, United States, for example, as described in <CIT>; <CIT>; and/or <NUM>,<NUM>,<NUM>. Although an AID device and insulin are used in examples in the present disclosure, embodiments are not so limited, as fluid delivery device <NUM> may be or may include a device capable of storing and delivering any fluid therapeutic agent, drug, medicine, hormone, protein, antibody, and/or the like.

Fluid delivery device <NUM> may include a delivery system <NUM> having a number of components to facilitate automated delivery of a fluid to patient <NUM>, including, without limitation, a reservoir <NUM> for storing the fluid, a pump <NUM> for transferring the fluid from reservoir <NUM>, through a fluid path or conduit, and into the body of patient <NUM>, and/or a power supply <NUM>. Fluid delivery device <NUM> may include at least one penetration element (not shown) configured to be inserted into the skin of the patient to operate as a conduit between reservoir <NUM> and patient <NUM>. For example, penetration element may include a cannula and/or a needle. Embodiments are not limited in this context, for example, as delivery system <NUM> may include more or fewer components.

In some embodiments, fluid delivery device <NUM> may include at least one sensor <NUM> operative to detect, measure, or otherwise determine various physiological characteristics of patient <NUM>. For example, sensor <NUM> may be or may include a continuous glucose monitoring (CGM) sensor operative to determine blood glucose measurement values of patient <NUM>. In another example, sensor may be or may include a heart rate sensor, temperature sensor, and/or the like.

In various embodiments, fluid delivery device <NUM> may be a closed-loop fluid delivery system using sensor <NUM> as an internal monitor to track patient information, either directly or via control device <NUM>, to delivery system <NUM> to formulate delivery of a fluid to patient <NUM> via the penetration element.

In some embodiments, computing device <NUM> may be a smart phone, PDM, or other mobile computing form factor in wired or wireless communication with fluid delivery device <NUM>. For example, computing device <NUM> and Fluid delivery device <NUM> may communicate via various wireless protocols, including, without limitation, Wi-Fi (i.e., IEEE <NUM>), radio frequency (RF), Bluetooth™, Zigbee™, near field communication (NFC), Medical Implantable Communications Service (MICS), and/or the like. In another example, computing device <NUM> and fluid delivery device <NUM> may communicate via various wired protocols, including, without limitation, universal serial bus (USB), Lightning, serial, and/or the like. Although computing device <NUM> (and components thereof) and fluid delivery device <NUM> are depicted as separate devices, embodiments are not so limited. For example, in some embodiments, computing device <NUM> and fluid delivery device <NUM> may be a single device. In another example, some or all of the components of computing device <NUM> may be included in fluid delivery device <NUM>. For example, Fluid delivery device <NUM> may include processor circuitry, memory unit, and/or the like. In some embodiments, each of computing device <NUM> and fluid delivery device <NUM> may include a separate processor circuitry, memory unit, and/or the like capable of facilitating insulin infusion processes according to some embodiments, either individually or in operative combination. Embodiments are not limited in this context.

<FIG> illustrates an exemplary wearable fluid delivery device in accordance with the present disclosure. In particular, <FIG> depicts a top-down view of a wearable fluid delivery device <NUM>. As shown in <FIG>, a wearable fluid delivery device <NUM> may include multiple systems to store and delivery a fluid to a patient. Fluid delivery device <NUM> may include one or more housings configured to enclose the multiple systems. In some embodiments, wearable fluid delivery device <NUM> may include a pump <NUM>. In various embodiments, pump <NUM> may be or may include a reciprocating pump (see, for example, <FIG>, <FIG>). In exemplary embodiments, wearable fluid delivery device <NUM> may include a reservoir <NUM> for storing a fluid. Reservoir may be in fluid communication with pump <NUM> for delivering the fluid to patient via needle <NUM>.

In various embodiments, pump <NUM> may be a multi-dose reciprocating pump. In some embodiments, pump <NUM> may be configured to deliver about <NUM> microliters per pulse. In exemplary embodiments, pump <NUM> may have a footprint of about <NUM> millimeters (mm) × <NUM> × <NUM>.

<FIG> illustrates an embodiment of a fluid delivery pump in accordance with the present disclosure. As shown in <FIG>, a fluid delivery pump <NUM> may include a ratchet or ratchet wheels <NUM> operably coupled to a snail cam (not shown, see, for example, <FIG>), a reservoir inlet <NUM> fluidically coupled to a reservoir (not shown), and a patient outlet <NUM> fluidically coupled to a needle <NUM>. Rotation of ratchet wheels <NUM> may cause fluid to flow from the reservoir to a pump chamber <NUM> or through needle <NUM> to patient depending on a flow path state, for instance, whether the pump is in a chamber fill state (fluid fill state) or a patient infusion state (fluid delivery state), respectively.

A fluid path valve <NUM> may be configured to switch the flow path state of pump <NUM> from a first state (for instance, a fluid fill state or chamber fill state) to a second state (for instance, a fluid delivery state or patient infusion state).

In some embodiments, fluid path valve <NUM> may include a fixed portion <NUM> and a movable portion <NUM>. In some embodiments, fixed portion <NUM> may be an outer wall of fluid path valve <NUM>. In various embodiments, fixed portion <NUM> may be a V-feature. In exemplary embodiments, movable portion <NUM> may pivot about a pivot point. In various embodiments, movable portion <NUM> may be a pivotable inner wall of fluid path valve <NUM>. In some embodiments, movable portion <NUM> may be or may include a bistable push-push mechanism (push-push mechanism, bistable mechanism, or inner wall).

A detent (or shaft, rod, pin, and/or the like) <NUM> may be configured to engage V-feature <NUM> and/or bistable mechanism <NUM> to set the state of fluid path valve <NUM>. In some embodiments, detent <NUM> may be coupled to a bracket <NUM> or other structure. In various embodiments, forces intended to move detent <NUM> may be wholly or partially imparted on bracket <NUM> to move detent <NUM>. In other embodiments, forces intended to move detent <NUM> may be wholly or partially imparted directly on detent <NUM>.

Although element <NUM> is described in examples in the present disclosure as a bistable mechanism, push-push mechanism, or bistable push-push mechanism, embodiments are not so limited. For example, element <NUM> may be or may include other mechanisms besides a bistable mechanism, push-push mechanism, or bistable push-push mechanism. In another example, element <NUM> is not limited to a bistable mechanism, push-push mechanism, or bistable push-push mechanism or may be a push-push mechanism with more than two states. Rather, use of examples of a bistable mechanism, push-push mechanism, or bistable push-push mechanism are intended to provide illustrative functional embodiments of element <NUM>. Accordingly, element <NUM> may be or may include any mechanism, element, structure, and/or the like capable of operating according to some embodiments.

Although element <NUM> is described in examples in the present disclosure as a V-feature, embodiments are not so limited. For example, element <NUM> is not required to be "V" shaped. Rather, use of a "V" shape or the term V-feature are not intended to be limiting but are intended to provide illustrative functional embodiments of element <NUM>. Accordingly, element <NUM> may be or may include any mechanism, element, structure, and/or the like, with various different shapes, capable of operating according to some embodiments.

In some embodiments, forces intended to move detent <NUM> may be wholly or partially imparted on bracket <NUM> to move detent <NUM> may be actuated or moved by an actuator <NUM>. In various embodiments, actuator may be or may include an SMA wire operably coupled to detent <NUM> and/or a bracket <NUM>. In exemplary embodiments, a spring <NUM> may be operably coupled to detent <NUM> and/or a bracket <NUM>. In some embodiments, actuator <NUM> may impart a force on detent <NUM> to move detent in direction A (for instance, away from bistable mechanism <NUM>). In some embodiments, actuator <NUM> may impart a force on detent <NUM> to move detent in direction B (for instance, toward bistable mechanism <NUM>).

In some embodiments, a spring <NUM> may operate to bias detent <NUM>, for example, in the direction of arrow B. Accordingly, if actuator <NUM> is not providing a force to move detent <NUM> in the direction of arrow A, detent <NUM> may be biased in the direction of arrow B. For example, an SMA wire actuator <NUM> may be activated to move detent <NUM> in the direction of arrow A. Relaxation of SMA wire actuator <NUM> may cause detent <NUM> to move back in the direction of arrow B. In this manner, fluid path valve <NUM> may be switched between fluid path states (see, for example, <FIG>).

In some embodiments, actuator <NUM>, and other components of pump <NUM>, may be actuated via hardware and/or software of a wearable fluid delivery device and/or an external computing device communicatively coupled to wearable fluid delivery device (see, for example, <FIG>).

<FIG> illustrate an embodiment of a fluid delivery pump in accordance with the present disclosure. More specifically, <FIG> show a cross-sectional side view and a front view, respectively, of a fluid delivery pump <NUM>. In some embodiments, fluid delivery pump <NUM> may be a reciprocating pump.

As shown in <FIG>, pump <NUM> may include a ratchet wheel <NUM>, a snail cam <NUM>, a piston <NUM>, and a chamber <NUM>. In some embodiments, a fluid path of pump <NUM> may include a reservoir entrance to needle <NUM>, a chamber/needle passthrough <NUM>, and a needle <NUM> with a needle exit <NUM>. A fluid path valve <NUM> may include a V-feature <NUM> and a bistable mechanism <NUM>.

During operation of pump <NUM>, fluid path valve <NUM> may be placed in a chamber fill state, for example in which a reservoir (not shown) is open to chamber <NUM> and closed to needle <NUM> (and patient). Rotation of ratchet <NUM> may rotate past the drop off of snail cam <NUM> and piston <NUM> may reset to chamber <NUM>. Fluid path valve <NUM> may be switched to the patient infusion state, for example, in which chamber inlet <NUM> is closed to reservoir and needle <NUM> is open to chamber <NUM>. In the patient infusion state, rotation of ratchet <NUM> may cause fluid to be pumped from chamber <NUM>, through needle <NUM>, and into the patient.

<FIG> illustrates an embodiment of a fluid path valve in accordance with the present disclosure. More specifically, <FIG> depicts steps <NUM>-<NUM> of fluid path valve <NUM> as fluid path valve <NUM> transitions between states. As shown in <FIG>, fluid path valve <NUM> may include a fixed portion (or V-feature) <NUM> and a movable portion (or bistable mechanism) <NUM> operably coupled to a pivot element <NUM> configured to allow bistable mechanism <NUM> to pivot responsive to force provided by a shaft or detent <NUM>. In some embodiments, V-feature <NUM> and bistable mechanism <NUM> may form a path, for example, with V-feature <NUM> being configured as a fixed outer wall of the path and bistable mechanism <NUM> being an inner wall of the path (that pivots on pivot element <NUM>).

In some embodiments, V-feature <NUM> may include a path, groove, inset, slot, wall, or other structure that may guide detent <NUM>, for example, responsive to forces imparted by an actuator and/or spring. In various embodiments, V-feature <NUM> may be offset or non-parallel and/or may include projections to cause detent <NUM> to deflect in a desired direction. In exemplary embodiments, bistable mechanism <NUM> may have an offset or projection <NUM> (for instance a tip of a triangular or substantially triangular portion) that may be offset to cause detent <NUM> to deflect in a desired direction. Projection <NUM> may form a first side, inner wall, extension, overhang, arm, or other structure <NUM> of bistable mechanism on a first side of projection <NUM> and a second side, inner wall, extension, overhang, arm, or other structure <NUM> on a second side of projection (first wall <NUM> and second wall <NUM> are only labeled in step <NUM> to limit the complexity of <FIG>). Projection <NUM> may be offset to cause detent <NUM> to deflect in a desired direction to engage first wall <NUM> or second wall <NUM> to cause bistable mechanism to tilt, pivot, or otherwise move in a desired direction to change a state of fluid path valve <NUM>.

At step <NUM>, fluid path valve <NUM> may be in a first state (for example, a chamber fill state). Detent may be pulled in direction C' at step <NUM>, for example, in response to an actuation by an SMA wire or other actuator (or conversely, due to the force of a biasing spring in the absence of actuation by an SMA wire). However, offset <NUM> (for instance, a triangular projection) of bistable mechanism <NUM> may be configured to cause detent <NUM> to deflect in direction C (for instance, to the right) and contact second wall <NUM>. For example, as detent <NUM> is pulled up toward bistable mechanism, detent <NUM> may hit at or near the point of the triangular projection of offset <NUM>, causing detent <NUM> to veer into direction C.

At step <NUM>, detent <NUM> may contact bistable mechanism <NUM> on the right side (for instance, at second wall <NUM>), causing bistable mechanism <NUM> to rotate counterclockwise. Fluid delivery valve may now be in a second state, such as a patient infusion state, after rotating to create an opening between V-feature <NUM> and second wall <NUM>. At step <NUM>, detent <NUM> may get pulled in direction D and come to a rest in a corner of V-feature <NUM>.

At step <NUM>, detent may be pulled in direction E', however, at this stage, the orientation of offset <NUM> of bistable mechanism <NUM> may cause detent <NUM> to deflect in direction E (for instance, to the left). At step <NUM>, detent <NUM> may contact bistable mechanism <NUM> on the left side (for instance, at first wall <NUM>), cause bistable mechanism <NUM> to rotate clockwise. At step <NUM>, detent <NUM> may get pulled in direction F and come to a rest in a corner of V-feature <NUM>.

Process of steps <NUM>-<NUM> may be repeated to switch the flow path from a first state (for instance, a chamber fill state) to a second state (for instance, a patient infusion state). For example, steps <NUM>-<NUM>, in which V-feature <NUM> is open on the upper right side, may be a first state, and steps <NUM>, <NUM>, and <NUM>, in which V-feature <NUM> is open on the upper left side may be a second state, or vice versa.

<FIG> illustrate operation states of an embodiment of a fluid delivery pump in accordance with the present disclosure. More specifically, <FIG> depict steps <NUM>-<NUM> of a fluid infusion process (for instance, including chamber fill and patient infusion processes), depicting a cross-sectional side view and a front view for a pump <NUM> according to some embodiments.

As shown in <FIG>, a pump <NUM> may include a ratchet <NUM>, snail cam <NUM>, piston <NUM> and chamber <NUM>. In some embodiments, a fluid path of pump <NUM> may include a reservoir entrance to needle <NUM>, a chamber/needle passthrough <NUM>, and a needle <NUM> with a needle exit <NUM>. A fluid path valve <NUM> may include a V-feature <NUM> and a bistable mechanism <NUM>.

In some embodiments, a detent <NUM> may be operably coupled to a bracket <NUM>/<NUM>. An actuator <NUM> may be operably coupled to bracket <NUM> to impart a force on detent <NUM>. In some embodiments, actuator <NUM> may be or may include an SMA wire that, when activated, may pull detent <NUM>. In exemplary embodiments, a spring <NUM>/<NUM> may be operably coupled to detent <NUM>/<NUM> and/or a bracket <NUM>/<NUM> to bias detent <NUM>/<NUM> (for instance, in the absence of a force by actuator <NUM>).

At step <NUM>, the fluid path is in a first position (for instance, a patient infusion position) such that rotation of ratchet wheel <NUM> may pump the fluid out of chamber <NUM> and into the patient. This infusion pulse may be repeated for multiple pulses, such as about <NUM> to about <NUM> pulses. Actuator <NUM> is deactivated, as indicated by X <NUM>. At step <NUM>, ratchet wheel <NUM> may stop (indicated by X <NUM> as the drop off of snail cam <NUM> approaches. In step <NUM>, pump <NUM> may stop moving the fluid (as indicated by X <NUM>) and the fluid path remains in the patient infusion position.

At step <NUM>, SMA <NUM> is activated, pulling detent <NUM> in direction G. Detent <NUM> may center on V-feature <NUM> and the fluid path may move out of the patient infusion position. At step <NUM>, SMA <NUM> is deactivated, initiating SMA release, causing detent <NUM> to move in direction H. Detent <NUM> may contact and cause rotation (for instance, clockwise rotation) of bistable mechanism <NUM>. The fluid path may move into a second position (for instance, a chamber fill position).

At step <NUM>, SMA release continues such that detent <NUM> continues moving in direction H. Detent <NUM> further rotates bistable mechanism <NUM> and moves the fluid path into the chamber fill position. At step <NUM>, ratchet wheel <NUM> may rotate and piston <NUM> may fall off of the drop off of snail cam <NUM>, creating a vacuum or negative pressure in chamber <NUM> that draws fluid from the reservoir, through <NUM> and into chamber <NUM>.

At step <NUM>, ratchet wheel <NUM> may stop moving and chamber <NUM> may be at least partially full of the fluid. The fluid path may be in a chamber fill (or non-infusion) position. At block <NUM>, SMA <NUM> may be activated, pulling detent <NUM> in direction H. Detent <NUM> may center on V-feature <NUM> and the fluid path may move out of the chamber fill position. At step <NUM>, SMA <NUM> may be deactivated and detent <NUM> may contact and rotate (for instance, counterclockwise) bistable mechanism <NUM>. The fluid path may be moved into the patient infusion position.

<FIG> illustrates an embodiment of a fluid path valve in accordance with the present disclosure. As shown in <FIG>, a fluid path valve <NUM> may include a V-feature <NUM> and a bistable mechanism <NUM>. In some embodiments, bistable mechanism <NUM> may include a beam <NUM>. In various embodiments, a shape of bistable mechanism <NUM> may be configured to reduce or even eliminate detent <NUM> from being caught, stuck, or otherwise trapped, either temporarily or permanently, in area <NUM> between bistable mechanism <NUM> and beam <NUM>. This embodiment may be used in the system shown in earlier figures.

<FIG> illustrates an embodiment of a fluid path valve in accordance with the present disclosure. As shown in <FIG>, a fluid path valve <NUM> may include a V-feature <NUM> and a bistable mechanism <NUM>. In some embodiments, bistable mechanism <NUM> may be associated with magnets. For example, a bottom face of path <NUM> and an inside wall <NUM> may have opposite magnetic charges. Accordingly, when detent <NUM> reaches the top of the path and pushes inside wall <NUM> over center, the opposite poles may operate to facilitate complete motion and prevent bistable mechanism <NUM> from passing back over center as detent <NUM> returns to the bottom (or corner) of V-feature <NUM>. For example, the magnets may operate to maintain bistable mechanism <NUM> in contact with V-feature on a closed side of fluid path valve <NUM> until detent <NUM> engages bistable mechanism <NUM> to pivot bistable mechanism <NUM> (i.e., to prevent bistable mechanism <NUM> from swinging back after detent <NUM> moves toward the V-section (inner corner) of V-feature <NUM>). This embodiment may be used in the system shown in earlier figures. Additionally or alternatively, there may be sufficient friction in the fluid path valve <NUM> such that when the bistable mechanism <NUM> rotates to one side, the friction in the fluid path valve <NUM> prevents the bistable mechanism <NUM> from rotating back to the center or toward the other side, until it is contacted again by detent <NUM>.

<FIG> illustrates an embodiment of a fluid path valve in accordance with the present disclosure. As shown in <FIG>, a fluid path valve <NUM> may include a V-feature <NUM> and a bistable mechanism <NUM>. In some embodiments, a beam <NUM> may be fixed at the center where it is connected to the inner walls of the path, constrained on either side <NUM> of fluid path valve <NUM>.

When detent <NUM> reaches a top of the path, detent <NUM> may cause the bends of beam <NUM> to invert, pushing the inner wall of bistable mechanism <NUM> over center. The bending forces and stresses of beam <NUM> may facilitate complete motion and prevent bistable mechanism <NUM> from passing back over center as detent <NUM> returns to the bottom (or corner) of V-feature <NUM>. This embodiment may be used in the system shown in earlier figures.

<FIG> illustrates an embodiment of a fluid path valve in accordance with the present disclosure. As shown in <FIG>, a fluid path valve <NUM> may include a V-feature <NUM> and a bistable mechanism <NUM>. V-feature <NUM> may be associated with drop offs <NUM> that may form paths or channels <NUM>. In some embodiments, drop offs <NUM> may cause detent <NUM> to only move in the direction indicated by the arrows (and in the opposite direction during a return process) in <FIG>, thereby preventing detent <NUM> from touching the inner wall (for instance, bistable mechanism <NUM>) and rotating it as detent <NUM> moves toward the corner of V-feature <NUM>, for example, only contacting bistable mechanism <NUM> when traveling toward bistable mechanism and not when traveling away from bistable mechanism <NUM> toward corner of V-feature <NUM>. In some embodiments, the paths <NUM> may slope up (for instance, out of the page of <FIG>) in the direction of the arrows of <FIG>. This embodiment may be used in the system shown in earlier figures.

While the present disclosure has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the certain embodiments have been shown and described.

Claim 1:
A fluid pump system (<NUM>) for a wearable fluid delivery device (<NUM>), comprising:
a pump chamber (<NUM>; <NUM>; <NUM>) to store a fluid;
a fluid path in fluid communication with the pump chamber and a reservoir (<NUM>; <NUM>);
a fluid path valve (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>) operative to control a state of the fluid path, the fluid path valve comprising a fixed portion (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>) and a movable portion (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>);
characterized by a shaft comprising a detent arm (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>; <NUM>) configured to move along the fixed portion responsive to a force imparted by an actuator (<NUM>; <NUM>),
wherein the fixed portion comprises a V-feature having a substantially V-shape, and wherein the movable portion comprises a substantially triangular projection extending from the movable portion to deflect a force of the shaft to cause the movable portion to pivot in one step from a first position to a second position, and in another step from the second position to the first position, responsive to being engaged by the shaft to change the state of the fluid path.