Infusion pump

Abstract

An infusion pump including multiple reservoirs arranged in series and / or parallel with one another is described. In some embodiments, flow channels with desired flow resistance arrangements, bypass flow paths, pressure sensors, and / or meniscus control structures can be included in the infusion pump to provide a desired flow of one or more therapeutic compounds into and / or out of the infusion pump.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 048,969, filed on July 7, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The disclosed embodiments relate to infusion pumps and methods of operating the same. Background Art

[0004] Portable infusion pumps are typically used to deliver a desired composition, such as a therapeutic compound, to a subject over a long period of time. Depending on the specific application, a portable infusion pump can be used to deliver the desired composition subcutaneously, epidurally, and / or intravenously. Portable infusion pumps are typically used to deliver these compositions to subjects who require continuous and / or repeated infusions of the composition for a specific treatment. For example, certain diseases such as diabetes, cancer, chronic pain, infections, gastrointestinal disorders, and other conditions may benefit from treatment using a portable infusion pump. Summary of the Invention

[0005] In one aspect, an infusion pump is provided. In some embodiments, the infusion pump includes a plurality of reservoirs connected in series. Flow resistance between adjacent reservoirs in the plurality of serially connected reservoirs increases in a downstream direction. The infusion pump also includes an outlet, and a last downstream reservoir in the plurality of serially connected reservoirs is fluidically connected to the outlet.

[0006] In another aspect, an infusion pump is provided. In some embodiments, the infusion pump includes a first reservoir, a second reservoir, a third reservoir, an outlet of the infusion pump, a first channel extending between the first reservoir and the second reservoir, a second channel extending between the second reservoir and the third reservoir, and a third channel extending between the third reservoir and the outlet of the infusion pump. The flow resistance of the third channel is greater than the flow resistance of the second channel, and the flow resistance of the second channel is greater than the flow resistance of the first channel.

[0007] In yet another aspect, a method is provided. In some embodiments, the method of operating an infusion pump includes: flowing a liquid from a first reservoir to a second reservoir through a first channel having a first flow resistance; and flowing the liquid from the second reservoir to an outlet of the infusion pump through a second channel having a second flow resistance greater than the first flow resistance.

[0008] In yet another aspect, an infusion pump is provided. In some embodiments, the infusion pump includes a first reservoir, a second reservoir, a chamber, and an outlet of the infusion pump. The first reservoir and the second reservoir are fluidically connected to the chamber in parallel, and the outlet of the infusion pump is fluidically connected to the chamber.

[0009] In yet another aspect, an infusion pump is provided. In some embodiments, the infusion pump includes a first plurality of serially connected reservoirs, a second plurality of serially connected reservoirs, a chamber, and an outlet of the infusion pump. The first plurality of serially connected reservoirs and the second plurality of serially connected reservoirs are fluidically connected to the chamber in parallel, and the outlet of the infusion pump is fluidically connected to the chamber.

[0010] In yet another aspect, a method is provided. In some embodiments, a method of operating an infusion pump comprises: flowing a first liquid from a first reservoir to a chamber; flowing a second liquid from a second reservoir to the chamber in parallel with the first liquid; mixing the first liquid and the second liquid; and flowing the mixture of the first liquid and the second liquid through an outlet of the infusion pump.

[0011] In yet another aspect, an infusion pump is provided. In some embodiments, the infusion pump includes a first reservoir, a second reservoir, a main channel fluidically coupling the first reservoir to the second reservoir, and a bypass channel fluidically coupling the first reservoir to the second reservoir. The bypass channel is separate from at least a portion of the main channel, and the bypass channel is configured to prevent liquid from flowing through the bypass channel below a pressure threshold and to allow liquid to flow through the bypass channel above the pressure threshold.

[0012] In yet another aspect, a method is provided. In some embodiments, a method of operating an infusion pump includes: flowing a liquid between a first reservoir and a second reservoir through a main channel at a first pressure below a pressure threshold; and flowing the liquid between the first reservoir and the second reservoir at a second pressure above the pressure threshold, wherein, when the liquid flows between the first reservoir and the second reservoir at the second pressure, at least a portion of the liquid bypasses at least a portion of the main channel.

[0013] In yet another aspect, an infusion pump is provided. In some embodiments, the infusion pump includes a first elongated reservoir, a first inlet disposed on an upstream portion of the first elongated reservoir, and a first outlet disposed on a downstream portion of the first elongated reservoir. The first elongated reservoir is sized and shaped such that liquid flowing into the first elongated reservoir through the first inlet forms a first meniscus, wherein the first outlet is offset in a transverse direction from a longitudinal axis of the first elongated reservoir. A downstream portion of the first elongated reservoir adjacent to the first outlet is configured to direct a portion of the first meniscus disposed on an opposite side of the longitudinal axis toward the first outlet.

[0014] In yet another aspect, a method is provided. In some embodiments, a method of operating an infusion pump includes flowing liquid through a first inlet of a first reservoir to form a first meniscus across a width of the first reservoir; displacing the first meniscus along the length of the first reservoir as the liquid fills the first reservoir; and reducing a profile of the meniscus to direct the first meniscus toward a first outlet of the first reservoir.

[0015] In yet another aspect, an infusion pump is provided. In some embodiments, the infusion pump includes a reservoir extending from an upstream portion of the reservoir to a downstream portion of the reservoir, and the reservoir includes a first inner surface disposed on a first side of a longitudinal axis of the reservoir and a second inner surface disposed on a second side of the longitudinal axis opposite the first side. The infusion pump also includes an inlet formed in the upstream portion of the reservoir and an outlet formed in the downstream portion of the reservoir on the second side of the longitudinal axis. The curvature of the first inner surface near the outlet is greater than the curvature of the second inner surface near the outlet.

[0016] On the other hand, an infusion pump is provided. In some embodiments, the infusion pump includes a plurality of elongated reservoirs connected in series. Each elongated reservoir includes an inlet disposed on an upstream portion of the elongated reservoir and an outlet disposed on a downstream portion of the elongated reservoir, wherein the elongated reservoir is sized and shaped such that liquid flowing through the inlet forms a meniscus, wherein the outlet is offset in a transverse direction from a longitudinal axis of the elongated reservoir. The downstream portion of each elongated reservoir is adjacent to the outlet and is configured to guide portions of the meniscus disposed on opposite sides of the longitudinal axis toward the outlet. In addition, the inlets and outlets of the plurality of elongated reservoirs are fluidically connected in series.

[0017] In yet another aspect, an infusion pump is provided. In some embodiments, the infusion pump includes: at least one reservoir; a chamber fluidly connected to the at least one reservoir; an outlet of the infusion pump fluidly connected to the chamber; a sensor configured to sense pressure in the chamber; at least one pump operatively coupled to the at least one reservoir and configured to pump liquid from the at least one reservoir to the chamber and through the outlet of the infusion pump; and a processor operatively coupled to the sensor and the at least one pump. The processor is configured to control operation of the at least one pump based at least in part on the sensed pressure in the chamber.

[0018] In yet another aspect, a method is provided. In some embodiments, a method of operating an infusion pump includes: flowing liquid from at least one reservoir through a chamber to an outlet of the infusion pump; sensing a pressure in the chamber; and controlling the flow of liquid from the at least one reservoir based at least in part on the sensed pressure in the chamber.

[0019] In yet another aspect, an infusion pump is provided. In some embodiments, the infusion pump includes at least one reservoir, a chamber, at least one channel fluidically connecting the at least one reservoir to the chamber, an outlet channel, an outlet of the infusion pump, and a pressure sensor configured to sense pressure within the chamber. The outlet channel fluidically connects the chamber to the outlet of the infusion pump, and the chamber has a maximum transverse dimension greater than a maximum transverse dimension of the at least one channel and the outlet channel.

[0020] In any of the foregoing embodiments, the infusion pump comprises a plurality of channels. In some embodiments, each reservoir located upstream of the last downstream reservoir is connected to an adjacent downstream reservoir in the series connection of reservoirs via at least one channel from the plurality of channels. In some embodiments, the plurality of channels are configured to provide increasing flow resistance between adjacent reservoirs in a downstream direction.

[0021] In any of the above embodiments, the infusion pump comprises an outlet channel fluidly connected to the last downstream reservoir and the outlet of the infusion pump.

[0022] In any of the above embodiments, the infusion pump comprises at least one therapeutic compound disposed in a reservoir.

[0023] In any of the foregoing embodiments, the infusion pump comprises at least one pump operatively coupled to at least one of the reservoirs. In some embodiments, the at least one pump comprises a plurality of pumps. In some embodiments, each pump is operatively coupled to a separate reservoir of the plurality of serially connected reservoirs.

[0024] In any of the above embodiments, the infusion pump includes a fill port fluidly connected to a first reservoir / first upstream reservoir of the plurality of serially connected reservoirs.

[0025] In any of the foregoing embodiments, flowing the liquid from the second reservoir comprises flowing the liquid from the second reservoir to the third reservoir through the second channel, and flowing the liquid from the third reservoir to the outlet of the infusion pump.

[0026] In any of the foregoing embodiments, flowing the liquid from the third reservoir to the outlet comprises flowing the liquid through a third channel having a third flow resistance greater than the second flow resistance.

[0027] In any of the above embodiments, the method includes filling the first reservoir and the second reservoir through a fill port fluidly connected to the first reservoir.

[0028] In any of the foregoing embodiments, each channel in the plurality of channels has an average maximum transverse dimension that is less than an average maximum transverse dimension of an upstream channel in the plurality of channels.

[0029] In any of the above embodiments, the flow resistance between the last downstream reservoir and the outlet is greater than the flow resistance between the last downstream reservoir and an adjacent upstream reservoir in the plurality of reservoirs.

[0030] In any of the above embodiments, a maximum transverse dimension of each channel of the plurality of channels is between or equal to 0.1 mm and 1 mm.

[0031] In any of the above embodiments, the infusion pump includes a first pump operatively coupled to the first reservoir and a second pump operatively coupled to the second reservoir.

[0032] In any of the above embodiments, the infusion pump includes a processor operatively coupled to the first pump and the second pump. In some embodiments, the processor is configured to operate the first pump to provide a first flow rate, and the processor is configured to operate the second pump to provide a second flow rate different from the first flow rate.

[0033] In any of the foregoing embodiments, the infusion pump comprises a first therapeutic compound disposed in a first reservoir and a second therapeutic compound disposed in a second reservoir.

[0034] In any of the above embodiments, the infusion pump includes a first set of one or more pumps operatively coupled to a first plurality of serially connected reservoirs and a second set of one or more pumps operatively coupled to a second plurality of serially connected reservoirs.

[0035] In any of the above embodiments, the pumps are configured to be independently controlled.

[0036] In any of the above embodiments, the infusion pump comprises a first therapeutic compound disposed in a first plurality of serially connected reservoirs and a second therapeutic compound disposed in a second plurality of serially connected reservoirs.

[0037] In any of the above embodiments, the flow of the first liquid has a first flow rate, and the flow of the second liquid has a second flow rate different from the first flow rate.

[0038] In any of the above embodiments, the first liquid comprises a first therapeutic compound and the second liquid comprises a second therapeutic compound.

[0039] In any of the foregoing embodiments, the infusion pump comprises an outlet of the infusion pump.In some embodiments, the second reservoir is fluidly coupled to the outlet of the infusion pump.

[0040] In any of the above embodiments, the liquid has surface tension and the bypass channel has a maximum transverse dimension at the opening into the first reservoir. In some embodiments, the surface tension and the maximum transverse dimension are configured to prevent the liquid from flowing through the bypass channel below a pressure threshold.

[0041] In any of the above embodiments, the bypass channel is completely separate from the main channel.

[0042] In any of the above embodiments, the bypass channel extends between a first upstream portion of the main channel and a second downstream portion of the main channel.

[0043] In any of the foregoing embodiments, the bypass channels have an average transverse dimension that is smaller than an average transverse dimension of the main channels.

[0044] In any of the above embodiments, the bypass channels have an average transverse dimension of between 0.05 mm and 0.5 mm.

[0045] In any of the above embodiments, the average transverse dimension of the main channels is between 0.1 mm and 2 mm.

[0046] In any of the above embodiments, the infusion pump comprises at least one therapeutic compound disposed in a first reservoir and a second reservoir.

[0047] In any of the above embodiments, the infusion pump comprises at least one pump operatively coupled to the first reservoir and the second reservoir.

[0048] In any of the above embodiments, the at least one pump includes a first pump operatively coupled to the first reservoir and a second pump operatively coupled to the second reservoir.

[0049] In any of the above embodiments, the infusion pump includes a fill port fluidly connected to the first reservoir.

[0050] In any of the foregoing embodiments, a method includes exceeding the surface tension of a liquid to cause the liquid to flow through a bypass channel to bypass a main channel.

[0051] In any of the foregoing embodiments, a method includes filling a first reservoir and a second reservoir through a fill port fluidly connected to the first reservoir.

[0052] In any of the above embodiments, the axis through the inlet is substantially parallel to the longitudinal axis of the reservoir.

[0053] In any of the above embodiments, the axis through the outlet is substantially parallel to the longitudinal axis of the reservoir.

[0054] In any of the above embodiments, the inlet is formed in an upstream portion of the reservoir.In some embodiments, the outlet is formed in a downstream portion of the reservoir on a second side of the longitudinal axis opposite the first side.

[0055] In any of the foregoing embodiments, the reservoir includes a first inner surface disposed on a first side of the longitudinal axis and a second inner surface disposed on a second side of the longitudinal axis opposite the first side. In some embodiments, the curvature of the first inner surface near the outlet is greater than the curvature of the second inner surface near the outlet.

[0056] In any of the above embodiments, the width of the reservoir tapers towards the outlet to direct the portion of the meniscus to the reservoir outlet.

[0057] In any of the above embodiments, the length of the reservoir parallel to the longitudinal axis of the reservoir is between or equal to 10 mm and 40 mm.

[0058] In any of the above embodiments, the maximum transverse dimension of the reservoir, perpendicular to the longitudinal axis of the reservoir, is between or equal to 5 mm and 15 mm.

[0059] In any of the above embodiments, a ratio of a radius of curvature of the first inner surface near the outlet to a radius of curvature of the second inner surface near the outlet is between or equal to 1 mm and 8 mm.

[0060] In any of the above embodiments, the reservoir is asymmetric.

[0061] In any of the foregoing embodiments, the infusion pump comprises at least one pump, the at least one pump comprising at least two pumps respectively associated with the at least two reservoirs. In some embodiments, the processor is configured to independently operate the at least two pumps based at least in part on the sensed pressure in the chamber.

[0062] In any of the above embodiments, the sensing area of ​​the pressure sensor is larger than the largest lateral dimension of the at least one channel and the outlet channel.

[0063] In any of the above embodiments, the at least one reservoir comprises at least two reservoirs connected in parallel to the chamber.

[0064] In any of the above embodiments, at least two reservoirs contain different therapeutic compounds.

[0065] In any of the foregoing embodiments, the infusion pump comprises: at least one pump operatively coupled to the at least one reservoir and configured to pump liquid from the at least one reservoir into the chamber and through an outlet of the infusion pump; and a processor operatively coupled to the sensor and the at least one pump. In some embodiments, the processor is configured to control operation of the at least one pump based at least in part on the sensed pressure in the chamber.

[0066] In any of the above embodiments, the processor is configured to stop operation of the at least one pump when the detected pressure is greater than a threshold pressure.

[0067] In any of the above embodiments, the processor is configured to output an alarm when the sensed pressure rise is less than a predetermined pressure rise.

[0068] In any of the above embodiments, at least one pump comprises an electrochemical cell configured to generate gas to expel liquid from at least one reservoir. In some embodiments, the processor is configured to control the operation of the electrochemical cell based at least in part on the sensed pressure in the chamber.

[0069] In any of the above embodiments, a method includes stopping the flow of liquid when the detected pressure is greater than a threshold pressure.

[0070] In any of the above embodiments, a method includes determining that a sensed pressure rise is less than a predetermined pressure rise; and outputting an alarm when the sensed pressure rise is less than the predetermined pressure rise.

[0071] In any of the foregoing embodiments, controlling the flow of liquid from the at least one reservoir comprises controlling operation of the electrochemical cell to generate gas to displace liquid from the at least one reservoir based at least in part on the sensed pressure in the chamber.

[0072] In any of the foregoing embodiments, flowing liquid from at least one reservoir comprises flowing parallel streams of liquid from at least two reservoirs to the chamber.

[0073] In any of the foregoing embodiments, a method includes independently controlling parallel flows from at least two reservoirs based at least in part on sensed pressures in the chambers.

[0074] In any of the above embodiments, at least two reservoirs contain different therapeutic compounds.

[0075] It should be understood that the aforementioned concepts and the additional concepts discussed below may be arranged in any suitable combination, as the present disclosure is not limited in this respect. In addition, other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component illustrated in various figures may be represented by a like reference numeral. For clarity, not every component is labeled in every figure. In the drawings:

[0077] Figure 1 is a schematic cross-sectional view of one embodiment of an electrochemical actuator;

[0078] Figure 2 is a schematic cross-sectional view of one embodiment of an electrochemical actuator;

[0079] Figure 3 is a perspective view of one embodiment of an infusion pump;

[0080] Figure 4 is an exploded perspective view of one embodiment of an electrochemical actuator included in an infusion pump;

[0081] Figure 5 is a schematic perspective view of one embodiment of a laminated reservoir structure including a flow path formed therein;

[0082] Figure 6 is formed Figure 5 a schematic perspective view of a flexible membrane as part of a laminated reservoir structure;

[0083] Figure 7 is formed Figure 5 a schematic perspective view of a portion of a laminate reservoir structure including a rigid membrane having a flow path formed therein;

[0084] Figure 8 is one embodiment of a laminate structure forming a reservoir and flow path of an infusion pump;

[0085] Figure 9 is one embodiment of a laminate structure forming a reservoir and flow path of an infusion pump;

[0086] Figure 9A yes Figure 9 A cross-sectional view of a laminate structure;

[0087] Figure 10 is a cross-sectional view of one embodiment of an inlet;

[0088] Figure 11 It is a three-dimensional diagram of the assembly process of the entrance;

[0089] Figure 12 is a side view of an outlet of an infusion pump formed in a laminate structure;

[0090] 13A to 13B One embodiment of a reservoir is depicted;

[0091] Figure 14 depicts one embodiment of a flow path comprising reservoirs connected in series, wherein a bypass channel extends between adjacent reservoirs;

[0092] Figure 15 One embodiment of a filling process of adjacent reservoirs including a bypass channel at low pressure filling and high pressure filling is depicted;

[0093] Figure 16 Depicts one embodiment of parallel flow paths comprising serially connected reservoirs fluidly connected to associated inlets and outlets of a device;

[0094] Figure 17 is a perspective view of one embodiment of an infusion pump including a pressure sensor;

[0095] Figure 18 is a perspective view of the interface area between the flexible membrane and the pressure sensor; and

[0096] Figure 19 is a cross-sectional view of the interface area between a pressure chamber formed between a flexible membrane and a rigid membrane, or other structure where the pressure chamber contacts an associated pressure sensor. DETAILED DESCRIPTION

[0097] In order to provide a desired rate of substance delivery via an infusion pump, the infusion pump typically includes an expensive and / or bulky pump. These pumps can both increase size and limit the amount of therapeutic compound that can be delivered to a subject within a desired form factor. Accordingly, the inventors have recognized a need for a pump that has a smaller form factor, is easier to manufacture, provides modular volumetric capabilities, and / or offers improved accuracy relative to current infusion pumps.

[0098] In view of this, the inventors have recognized the benefits associated with the following infusion pump, which includes multiple reservoirs associated with one or more pumps, such as electrochemical actuators. Depending on the specific embodiment, the multiple reservoirs can be arranged in series and / or in parallel with each other. For example, in one embodiment, the infusion pump may include multiple reservoirs connected in series, which may or may not be positioned in parallel with one or more other groups of series-connected reservoirs. Alternatively, in some embodiments, the multiple reservoirs of the infusion pump may be positioned in parallel with each other. In some cases, it may be desirable to increase the flow resistance between adjacent reservoirs so that the flow resistance along a given flow path increases in the downstream direction. In particular, when used with multiple flow paths positioned in parallel with each other, such an arrangement can help to balance the filling rates of the flow paths during the filling process.

[0099] In addition to the above, in some embodiments, other hydraulic components and features may be included in the infusion pump. For example, in some embodiments, the infusion pump may include a bypass channel extending between adjacent reservoirs, which allows at least a portion of the liquid flow between the adjacent reservoirs to flow through the bypass channel to reduce the flow of liquid through one or more main channels extending between the reservoirs when the pressure is above a predetermined threshold. The reservoirs may also be configured to control the formation and velocity distribution of the meniscus during the filling process to help guide the meniscus toward the outlet of each reservoir, thereby helping to reduce the formation of bubbles during the filling process.

[0100] Using various combinations of the above methods and components, as well as other methods and components described herein, can help provide a robust infusion pump that is easy to manufacture and operate.

[0101] For clarity, the figures have depicted a single main channel and bypass channel extending between adjacent reservoirs. However, it should be understood that the various embodiments described herein may include a single or multiple main channels and bypass channels extending between adjacent reservoirs, as the present disclosure is not limited in this manner. Furthermore, in embodiments in which multiple bypass channels extend between adjacent reservoirs, the multiple bypass channels may have the same threshold pressure and / or different threshold pressures above which liquid may flow through the bypass channel to a downstream reservoir, as the present disclosure is not limited in this manner.

[0102] Turning to the drawings, certain non-limiting embodiments are described in further detail. It should be understood that the various systems, components, features, and methods described with respect to these embodiments may be used alone and / or in any desired combination, as the present disclosure is not limited to the specific embodiments described herein.

[0103] Figure 1 A schematic diagram of an embodiment of an electrochemical actuator 10 as described herein is presented that can be operated using gas electrolysis. Specifically, electrodes 20 disposed within an electrolysis chamber 30 apply a voltage difference to an electrolyte disposed within the electrolysis chamber to separate the electrolyte into gases. The released gas generates pressure for driving a therapeutic compound or other suitable composition to flow from the actuator. The reservoir containing the therapeutic compound or other composition and the electrolysis chamber are separated by a flexible membrane 60 so that the electrolyte does not mix with the drug. The flexible membrane can exhibit desired mechanical flexibility and barrier properties for the specific application in which it is used. The amount of therapeutic compound removed from the reservoir can be determined by the amount of gas generated in the actuator. The amount of gas generated is determined by the total charge passed through the two electrodes, which can be measured using an appropriate current sensor, a coulomb counting sensor, or other appropriate type of sensor.

[0104] Figure 2 Another embodiment of an electrochemical actuator is depicted. In the depicted embodiment, the electrochemical actuator includes a sealed chamber formed in a rigid structure 50 in the form of an electrolysis chamber 30 and including a bottom portion and one or more side portions extending from the bottom portion. In some embodiments, the rigid structure 50 is a unitary structure formed as a single, integral component. A flexible membrane 60 is sealed around an opening formed by the one or more side portions to form a sealed electrolysis chamber 30 containing an electrolyte. Two or more electrodes 20 can extend through the side portions and / or bottom portion of the rigid structure forming the sealed chamber into the interior of the sealed chamber. The electrodes 20 can be sealed to the rigid structure in any suitable manner to ensure that the chamber is sealed. A second flexible membrane is sealed to a separate rigid structure, such as a rigid membrane or other structure, to form a reservoir 70 between the second flexible membrane and the separate rigid structure to contain a desired therapeutic compound or other substance. The resulting reservoir 70 is then placed into the opening of the rigid structure, wherein the second flexible membrane of the reservoir is disposed on the first flexible membrane of the electrolysis chamber. The reservoir 70 can be held against the electrolysis chamber in any suitable manner, including, for example, gluing, welding, and / or clamping the reservoir against the first flexible membrane of the electrolysis chamber 30 within the opening. Thus, the first membrane of the electrolysis chamber can be deformed against the second membrane of the reservoir by the gas generated within the electrolysis chamber 30, thereby draining liquid from the reservoir 70 through the reservoir outlet.

[0105] In the above-described embodiment, a first flexible membrane is used to contain the electrolyte used for electrolysis within electrolysis chamber 30, and a second flexible membrane is in contact with the liquid therapeutic compound or other substance contained within filled reservoir 70. Advantageously, reservoir 70 can undergo a manufacturing process independent of the manufacturing process of electrolysis chamber 30. This approach offers several advantages in isolating the therapeutic compound or other substance from potential interaction with the electrolyte used for electrolysis. This approach can also facilitate quality control procedures for both items. Given the technical requirements for therapeutic compound packaging and electrolyte containment, this manufacturing method can also increase the number of available options for materials used in the construction of these components.

[0106] Figure 3 A perspective view of the infusion pump 1 is depicted. Figure 4 One embodiment of the internal system of an infusion pump 1 is shown. Specifically, in the depicted embodiment, the infusion pump includes one or more electrochemical actuator arrays, which include multiple reservoirs 70 and corresponding electrolysis chambers 30. In the depicted arrays, the overall approach is the same: a group of reservoirs 70 and a corresponding group of electrolysis chambers 30 can include corresponding rigid structures and flexible structures similar to the above-described embodiments. However, in some embodiments, it may be advantageous to form multiple reservoirs between a single rigid structure 50, such as a rigid film, and a corresponding flexible film 60 bonded to the rigid film. In addition, multiple electrolysis chambers can be formed in a rigid integral structure, wherein a single flexible film is bonded around the openings of the multiple electrolysis chambers to form the desired sealed electrolysis chambers. These structures can be assembled and held close to each other to form an entire electrochemical actuator for pumping substances out of the reservoirs.

[0107] In the depicted embodiment, the entire device can include eight separate reservoirs, or any other suitable number of separate reservoirs, which can be fluidically connected to a common outlet and / or separate outlets from the device, as the present disclosure is not so limited. In either case, the depicted configuration can simplify the manufacture of multiple electrochemical actuators using multiple structures formed in the various described rigid and flexible components. In addition, as further described below, the rigid membrane or other structure forming part of the reservoir can include one or more channels or other hydraulic components that define the overall layout and function of the resulting hydraulic circuit that is in fluid communication with the various reservoirs of the electrochemical actuator.

[0108] Figures 5 to 7 Depicted is the construction of one embodiment of an array of reservoirs 70 formed from two laminated films. The laminate is made from two thermoformed films that are heat sealed to form a fluid path. In some embodiments, one or more fluid paths are formed from, for example, Figure 7The relatively rigid film 50 shown in FIG is formed, and the relatively rigid film 50 is relatively rigid. Figure 6 The flexible membrane 60 shown in the figure is more rigid and is placed against the flexible portion of the corresponding electrolysis chamber to form an interconnected electrochemical actuator array. The laminate is made of an extruded film made of a material having a desired combination of flexibility, chemical stability, and compatibility with the composition contained in one or more reservoirs. Once each membrane has been subjected to the thermoforming process, the membrane can be cut to include alignment features and through-holes for the inlet and outlet structures. A simple lamination process similar to pill packaging lamination, in which a cavity containing offset features of each thermoformed membrane can be used to provide heat and pressure in selected areas of the laminated construction.

[0109] Although the thermoforming process for each film is described above, in some embodiments, the rigid portion of the reservoir can be injection molded to form a desired flow path. During actuation, the flexible actuator layer deforms to discharge the composition from the reservoir 70. However, the flow path does not need to move. Therefore, other parts of the laminate structure can be thicker and can therefore be injection molded and / or otherwise formed in a thicker, more rigid structure. Thermoformed film or other structures including the flow path can be bonded or welded to the flexible film to form both the reservoir 70 and the associated one or more flow paths 12. Figures 8 to 9A Different views of the resulting structure and associated reservoirs and flow paths are shown in .

[0110] Figures 10 and 11 One embodiment of an inlet 15 in fluid communication with one or more reservoirs of an infusion pump is illustrated. The inlet can include a receiver 16, a septum 17, and a base 18. The receiver 16 and base 18 can be rigid components that prevent accidental puncture of the fluid laminate during filling and compression of the septum 17 to achieve a seal after filling the device. Assembly of the inlet can include the steps of: heat bonding the base 18 to the fluid laminate 19; press fitting the septum 17 into the receiver 16; and heat riveting or ultrasonically welding the receiver 16 to the assembly. However, it should be understood that other suitable assembly processes and structures can be used for the inlet in fluid communication with the reservoir, as the present disclosure is not limited thereto.

[0111] Figure 12An embodiment of an outlet 25 for administering fluids in conjunction with multiple reservoirs of an infusion pump is depicted. In the depicted embodiment, the outlet 25 includes five components, including: a receiver 26; a receiver septum 27; a dispenser 28; a base 29; and a base septum 24. The outlet 25 can be heat-sealed to the microfluidic laminate 19 and can be mechanically sealed to the cannula during use. Initially, the dispenser 28 and the base 29 can compress the base septum 24. This compression becomes permanent by laminating the dispenser 28 and the base 29 to the microfluidic laminate 19. Once the heat lamination process is complete, the receiver septum 24 is placed in the dispenser 28 and the receiver 26 is ultrasonically welded to the base 29, which can fix the compression level of the receiver septum 27 and the alignment of portions of the inserter (including the associated cannula) and portions of the outlet 25. The receiver septum 24 is not intended to be pierced, but can behave more like an O-ring or other seal when pressed against a support post. Therefore, in some cases, in other portions of this application, the receiver diaphragm 24 may be synonymously referred to as a seal.

[0112] While a particular arrangement of outlets for an infusion pump associated with a plurality of electrochemical actuators has been described above, it should be understood that any suitable arrangement of outlets for an infusion pump may be used, as the present disclosure is not limited to any particular configuration.

[0113] In some cases, the infusion pump can be configured to be filled by the user to allow for reuse of the infusion pump and / or delivery of any desired combination of therapeutic compounds or other compositions. Thus, in some embodiments, the infusion pump can include a flow path configured to accommodate user filling at relatively high flow rates (≤30 ml / min). In order to accommodate user filling at these relatively high flow rates, it may be desirable for the reservoir and flow path of the device to be configured to facilitate bubble-free filling of the reservoir and / or filling of the reservoir at an angle relative to the direction of local gravity. Specific embodiments of structures capable of filling under these conditions, such as bypass channels and reservoir geometries, are described in detail below.

[0114] In view of the above, the reservoirs and associated channels, as well as other hydraulic components of the device, can be configured to provide laminar flow of the liquid through the device, which minimizes the likelihood of the fluid transitioning to turbulent flow. Thus, the channel entrance to each reservoir can be gradually widened to slow the fluid momentum and reduce the Reynolds number upon entry (although higher Reynolds numbers can also be used for liquids with viscosities greater than that of water). For example, during filling of the reservoirs, as the meniscus advances along the length of each reservoir, the Reynolds number can be maintained below 2300.

[0115] Once the fluid enters the reservoir under laminar flow, a significant challenge is maintaining the laminar flow and preventing unintended air bubble entrapment during filling. 13A to 13B A ratio of width W1 and height H1 in the reservoir close to 3:2 and having a height limit of 5 mm significantly improves bubble-free filling. In addition, as the meniscus progresses within the reservoir, it has been found that the fluid may converge asymmetrically due to limitations in the manufacture, assembly and / or filling of the reservoir. Therefore, in some embodiments, it may be preferred to use an asymmetric shape of the reservoir to force an asymmetric velocity vector as the fluid approaches the outlet, the asymmetric shape being configured to direct the flow of the fluid and the resulting meniscus toward the outlet of the reservoir to avoid bubble formation. In some embodiments, this can be achieved by offsetting the outlet channel from the centerline of the channel width to the desired convergence side while maintaining a minimum ratio of the relevant radii of curvature of adjacent outlets of the reservoir (ratio of radii of curvature R3:R2, e.g. Figure 13A ) is greater than or equal to 4: 1. However, embodiments using different ratios of various geometries are also contemplated, including ratios greater than and less than the above-described ratios.

[0116] Figure 14 An embodiment of a plurality of reservoirs 70 connected in series is depicted, wherein a main channel 12 extends between adjacent upstream and downstream reservoirs. In addition, the flow path 12 can include a bypass channel 13 extending between adjacent upstream and downstream reservoirs such that at least a portion of the liquid flowing between the reservoirs can flow through the bypass channel. As described in detail below, due to capillary forces within the bypass channel, the liquid can not flow through the bypass channel when it is below a threshold pressure. Correspondingly, when the pressure within the reservoir is above the threshold pressure, such as may occur during a user filling the reservoir at a fill rate above the threshold, the liquid can flow through the bypass channel to reduce the flow through the main channel, which can help maintain the desired laminar flow and meniscus formation within the reservoir during filling.

[0117] Without being bound by theory, controlling the meniscus within each reservoir relies strongly on controlling the velocity vector in terms of direction and magnitude. Controlling the magnitude of the velocity vector can be done indirectly by providing a bypass channel 13 that is enabled based on a pressure threshold. Figure 15As can be observed in , a low-pressure filling process will only fill the capillary bypass between the two reservoirs 70 in series, but there will not be enough pressure to overcome the surface tension at the end of the bypass channel 13. Therefore, substantially all of the liquid flows through the main channel 12 to fill the next reservoir 70 in series. In contrast, a high-pressure filling process will result in a higher flow rate (Q2>Q1), so that the applied pressure overcomes the surface tension of the liquid at the opening of the bypass channel 13, so that a portion of the liquid will flow through the bypass channel 13, which can significantly reduce the fluid velocity of the fluid flowing through the main channel 12. This can help to keep the velocity vector of the fluid flowing through the main channel 12 less than a desired threshold velocity, and in some cases can result in the velocities in each scenario being approximately equal to each other (V f1 ~V f2 ).

[0118] Figure 16 An embodiment of two or more sets of series-arranged reservoirs 71-74 connected in series to the inlet 15 and / or outlet 25 of an infusion pump is depicted. In embodiments comprising two or more parallel liquid flows, it may be desirable to maintain relatively equal flow along a single flow path through the series-arranged reservoirs and / or between parallel branches during filling and / or pumping of liquid through the device. For example, in practice, when a fluid path begins filling during a filling process in which an inlet is connected to two parallel flow paths, there may be variations and defects in the flow paths that could prevent the branches from completing filling simultaneously. If this problem is exacerbated downstream, a considerable amount of gas may be trapped between the convergence point of the parallel branches and the slower meniscus. One way to achieve simultaneous filling with minimal bubble formation may be to increase the hydraulic resistance of each flow path in the downstream direction. In this figure, it can be observed how the channels connecting the two fluid branches containing the two reservoirs each include a cross-sectional area that decreases in size in the downstream direction, which increases the hydraulic resistance of each parallel flow path in the downstream direction. Corresponding portions of the parallel flow paths can have approximately equal hydraulic resistances to each other to provide substantially similar flow characteristics along each parallel flow path. Because hydraulic resistance increases in the downstream direction, once one reservoir is filled and the meniscus enters the channel with increased hydraulic resistance, the flow rate of liquid entering the other parallel branches that have not yet filled to the same extent can be accelerated, allowing the filling of each branch to be automatically adjusted to keep the filling rate of each branch approximately equal to each other. For example, if point 121 exhibits a 5% higher hydraulic resistance than point 122, reservoir 72 will be filled at a higher flow rate. However, once reservoir 72 is filled, the hydraulic resistance will increase exponentially for branch 12A along reservoirs 72 and 74, and the flow rate at point 121 will increase significantly, thereby quickly minimizing the difference in filled volumes between the two branches.

[0119] In some embodiments, it may be desirable to include one or more feedback mechanisms to provide dose confirmation and / or pump status. However, for infusion pumps that include a laminated structure forming a reservoir and a corresponding flow path, it may be difficult to interface circuits and / or sensors with the fluid path in an inexpensive and reliable manner. Therefore, in some embodiments, an interface between a flexible membrane of the fluid path and other electromechanical components such as switches, pressure sensors, strain gauges, light-based distance sensors, etc., may be used as a feedback mechanism for dose control. For example, Figures 17 to 19 As shown in , the infusion pump may include an interface between a flexible layer 60 forming a reservoir of the device and a pressure sensor 82, such as a force sensor, strain gauge, force switch or other suitable sensor. In one such embodiment, a 0.5N tactile switch may be used. A corresponding chamber may be formed between the flexible membrane 60 and a corresponding rigid membrane 50 or other structure so that a desired threshold force is used to activate a switch or other sensor for a predetermined operating pressure of the device. During operation, the flexible membrane may be pressed against the sensor. Therefore, when an occlusion at the cannula causes pressure to build up in the fluid path, the force applied to the button or other sensor is directly related to the internal pressure and the interface area between the button and the flexible membrane. By modifying the interface area 820 (such as Figure 18 ), the threshold pressure for actuating the button or a threshold pressure that can be sensed by another suitable sensor can be easily adjusted. For a 0.5N device to be triggered at a target occlusion pressure of 30 kPa, the diameter of the interface area can be approximately 4.6 mm. However, it should be understood that other threshold pressures, interface areas, and / or sensor and chamber configurations can be used, as the present disclosure is not limited in this manner.

[0120] Although the present invention has been described in conjunction with various embodiments and examples, it is not intended that the present invention be limited to such embodiments or examples. On the contrary, as will be appreciated by those skilled in the art, the present invention encompasses various alternatives, modifications, and equivalents. Therefore, the foregoing description and accompanying drawings are intended only as examples.

Claims

1. An infusion pump comprising: a plurality of reservoirs connected in series; as well as an outlet of the infusion pump, wherein a last downstream reservoir of the plurality of serially connected reservoirs is fluidly connected to the outlet; a plurality of channels, wherein each reservoir upstream of the last downstream reservoir is connected to an adjacent downstream reservoir of the series-connected reservoirs by at least one channel of the plurality of channels; wherein the plurality of reservoirs connected in series form at least two branches, wherein the infusion pump comprises an inlet fluidly connected to a first upstream reservoir of the plurality of serially connected reservoirs, wherein the plurality of channels are configured to provide increased flow resistance between adjacent reservoirs in the downstream direction with decreasing dimensions, enabling automatic adjustment of the filling rate of each of the at least two branches to achieve automatic regulation of the filling of each branch to maintain the filling rate of each branch approximately equal to one another, thereby achieving simultaneous filling with minimal bubble formation.

2. The infusion pump of claim 1 , wherein the plurality of serially connected reservoirs comprises: a first reservoir; a second reservoir; a third reservoir; The plurality of channels include: a first channel extending between the first reservoir and the second reservoir; a second passage extending between the second reservoir and the third reservoir; and a third channel extending between the third reservoir and the outlet of the infusion pump, wherein a flow resistance of the third channel is greater than a flow resistance of the second channel, and wherein the flow resistance of the second channel is greater than a flow resistance of the first channel.

3. The infusion pump of claim 1 or 2, further comprising an outlet channel fluidly connected to the last downstream reservoir and the outlet of the infusion pump.

4. The infusion pump of claim 1 or 2, further comprising at least one therapeutic compound disposed in the reservoir.

5. The infusion pump of claim 1 or 2, further comprising at least one pump operatively coupled to at least one of the reservoirs.

6. The infusion pump according to claim 5, wherein: The at least one pump comprises a plurality of pumps, and wherein each pump is operatively coupled to a separate reservoir of the plurality of serially connected reservoirs.

7. The infusion pump according to claim 1 or 2, wherein: A flow resistance between the last downstream reservoir and the outlet is greater than a flow resistance between the last downstream reservoir and an adjacent upstream reservoir in the plurality of reservoirs.

8. The infusion pump according to claim 1 or 2, wherein: A maximum transverse dimension of each channel of the plurality of channels ranges from 0.1 mm to 1 mm.

9. The infusion pump according to claim 1 or 2, wherein: Each channel of the plurality of channels has an average maximum transverse dimension that is less than an average maximum transverse dimension of an upstream channel of the plurality of channels.

10. The infusion pump according to claim 1, wherein The decreasing size of the plurality of channels refers to a decrease in cross-sectional area size in a downstream direction.

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