Positive displacement pump mechanism with dual reservoir

Abstract

Disclosed herein is a dual reservoir configuration for a space-efficient pump mechanism comprising an outer reservoir and an inner reservoir, where linear translation of the inner reservoir causes the inner reservoir to move into the outer reservoir and act as a plunger for the outer reservoir to force fluid contained therein through a first fluid port. A static plunger disposed within the inner reservoir forces fluid disposed within the inner reservoir through a second fluid port. Also disclosed are various drive mechanisms for causing linear movement of the first reservoir into the second reservoir.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 304,270, filed on January 28, 2022, the content of which is hereby incorporated by reference in its entirety.

Background Art

[0002] Many conventional automated drug delivery systems that include a wearable drug delivery device of the type shown, for example, in FIG. 2 are well known. The drug delivery device 102 can be designed to deliver any type of liquid drug to a user. In certain embodiments, the drug delivery device 102 can be, for example, an OmniPod® drug delivery device manufactured by Insulet Corporation of Acton, Massachusetts. The drug delivery device 102 can be a drug delivery device described in Patent Document 1 (U.S. Patent No. 7,303,549), Patent Document 2 (U.S. Patent No. 7,137,964), or Patent Document 3 (U.S. Patent No. 6,740,059), each of which is hereby incorporated by reference in its entirety.

[0003] The drug delivery device 102 typically includes a positive displacement pump mechanism. Typically, the pump mechanism includes a reservoir for storing a liquid drug. The liquid drug stored in the reservoir can be delivered to the user by pushing the drug out of the reservoir using a drive plunger that moves longitudinally through the reservoir and discharging the liquid drug through a defined fluid port in the reservoir. The plunger may be moved longitudinally through the reservoir by, for example, a rigid lead screw that pushes the plunger forward during pumping. When the reservoir is filled, the lead screw moves backward with the plunger. The lead screw extends beyond the back of the plunger by a distance equal to the plunger's stroke plus an additional amount to allow engagement with the drive mechanism. This creates space efficiency constraints when scaling the design. As the plunger stroke increases, the length of the lead screw must also increase by the same amount.

[0004] In devices worn on the body, it is desirable to keep the pump mechanism and the entire drug delivery device 102 as small as possible to minimize impact on the wearer. In addition, since such drug delivery devices are typically powered by an onboard battery, it is desirable to minimize the power required to operate the device.

[0005] Therefore, it is desirable to replace conventional pump mechanisms with positive displacement pumps that have a more space-efficient pump mechanism, enabling smaller devices to reduce the burden on users.

[0006] definition As used herein, the term “liquid drug” should be interpreted to include any drug in liquid form that can be administered by a drug delivery device via a subcutaneous cannula, such as insulin, GLP-1, pramulintide, morphine, antihypertensive drugs, chemotherapy drugs, reproductive drugs, or two or more co-formulations of GLP-1, pramulintide, and insulin. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] U.S. Patent No. 7,303,549 [Patent Document 2] U.S. Patent No. 7,137,964 [Patent Document 3] U.S. Patent No. 6,740,059 [Overview of the Initiative]

[0008] The summary of the present invention is provided in a simplified form to introduce a selection of concepts that will be further described in the following detailed description. The summary of the present invention is not intended to identify the main or essential features of the claimed subject matter, nor is it intended to be an aid in determining the technical scope of the claimed subject matter.

[0009] A primary embodiment of the present invention disclosed herein is a double reservoir configuration having a relatively large outer reservoir and a relatively small inner reservoir, wherein the inner reservoir has a slightly smaller cross-sectional shape than the outer reservoir so that the inner reservoir, which acts as a plunger for the outer reservoir, can move linearly through the outer reservoir. The two reservoirs are fluidly connected to each other via a rigid hollow rod, which is positioned between the inner and outer reservoirs and supports a static plunger for the inner reservoir, and as the inner reservoir moves linearly into the outer reservoir, the inner reservoir forces fluid from the outer reservoir into the inner reservoir via the hollow rod. The static plunger in the inner reservoir acts to force fluid out of the inner reservoir through a fluid discharge port as the inner reservoir is moved linearly into the outer reservoir.

[0010] The dual reservoir configuration utilizes a second reservoir and a static plunger to use the space occupied by the lead screw in the prior art example of a drug delivery device. This results in a more space-efficient configuration of the dual reservoir configuration compared to the prior art example. Modifications of the primary embodiment involve various methods for driving the inner reservoir into the outer reservoir, which are described in detail below.

[0011] In the drawings, similar reference numerals generally refer to the same parts throughout different drawings. In the following description, various embodiments of the present invention will be described with reference to the following drawings. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 shows a functional block diagram of an exemplary system suitable for carrying out the systems and methods disclosed herein. [Figure 2] Figure 2 is a diagram of a conventional wearable drug delivery device of the type in which the present invention disclosed herein is used. [Figure 3A-3D] Figures 3A to 3D are schematic cross-sectional views of a primary embodiment of the present invention, showing the outer reservoir, inner reservoir, hollow connecting rod, and static plunger when the device is filled with fluid and when fluid is being supplied. [Figure 4A-4B] Figures 4A and 4B are opaque perspective views of a first modification of the primary embodiment, in which a lead screw connected to the inner reservoir is rotated by a tube nut, driving the inner reservoir into the outer reservoir. [Figures 5A-5C] Figures 5A to 5C are opaque perspective views of a second modification of the primary embodiment, in which the lead screw is screwed into a push member, which pushes onto the rear surface of the inner reservoir to drive the inner reservoir into the outer reservoir as the lead screw rotates. [Figure 6A-6B]Figures 6A and 6B are opaque perspective views of a third modified example of the primary embodiment, in which the lead screw is screwed into the inner reservoir so as to drive the inner reservoir into the outer reservoir by the rotation of the lead screw. [Figures 7A-7B] Figures 7A and 7B are opaque perspective views of a fourth modified example of the primary embodiment, in which the rack and pinion configuration is used to move the outer reservoir toward the inner reservoir so as to drive the inner reservoir toward the outer reservoir. [Figures 8A-8B] Figures 8A and 8B are opaque perspective views of a fifth modified example of the primary embodiment, in which the two lead screws are screwed into the inner reservoir so that the synchronous rotation of the lead screws drives the inner reservoir into the outer reservoir. [Figure 9] Figure 9 is a schematic cross-sectional view of a secondary embodiment in which the inner reservoir is driven into the outer reservoir using a central lead screw and requires two fluid ports. [Figure 10A-10B] Figures 10A and 10B are opaque cross-sections of a secondary embodiment of the present invention, in which a central lead screw within the inner reservoir is used to drive the inner reservoir into the outer reservoir. [Figure 11A-11C] Figures 11A to 11C show different exemplary embodiments of reservoirs having different cross-sectional shapes. [Figures 12A-12B] Figures 12A and 12B show two possible embodiment plunger configurations suitable for use in all embodiments of the present invention. [Modes for carrying out the invention]

[0013] The present invention provides various systems, components, and methods for transferring liquid drugs from a liquid reservoir in a drug delivery device to a patient interface such as a needle or cannula. The embodiments described herein offer one or more advantages over conventional systems, components, and methods, namely, a smaller overall implementation range for drug delivery devices.

[0014] Various embodiments of the present disclosure include systems and methods for delivering a drug to a user using a drug delivery device (which may also be referred to herein as a “pod”) either autonomously or in accordance with a wireless signal received from an electronic device. In various aspects, the electronic device can be a smartphone, a smartwatch, a smart necklace, a user device comprising a module attached to the drug delivery device, or any other type or kind of electronic device that can execute an algorithm for calculating the number of times and dosage of drug delivery that can be carried by the user or worn on the user's body.

[0015] For example, the user device can execute an “artificial pancreas” (AP) algorithm for calculating the number of times and dosage of insulin delivery. The user device can also communicate with sensors such as a glucose sensor or a continuous glucose monitor (CGM) that collect data regarding the user's physical characteristics or conditions such as glucose concentration. The sensor can be placed inside or on the user's body, can be part of the drug delivery device, or can be a separate device.

[0016] Alternatively, the drug delivery device can communicate with the sensor instead of or in addition to the communication between the sensor and the user device. This communication can be direct (e.g., if the sensor is integrated with or is part of the drug delivery device) or remote / wireless (e.g., if the sensor is placed in a separate housing from the drug delivery device). In these embodiments, the drug delivery device comprises computer hardware (e.g., a processor, memory, firmware, etc.) that executes some or all of an algorithm for calculating the time and dosage of drug delivery.

[0017] FIG. 1 shows a functional block diagram of an exemplary drug delivery system 100 suitable for implementing the systems and methods described herein. The drug delivery system 100 can implement (and / or provide functionality for) a drug delivery algorithm, such as for an artificial pancreas (AP) application, to manage or control the automatic delivery of drugs or medications, such as insulin, to a user (e.g., to maintain a normal blood glucose - a normal blood glucose value in the blood). The drug delivery system 100 can be an automatic drug delivery system having a drug delivery device 102 (which can be wearable), a sample sensor 108 (which can be wearable), and a user device 105.

[0018] In any example, the drug delivery system 100 can also have an accessory device 106, such as a smartwatch, a personal assistant device, etc., that can communicate with other components of the system 100 via any of the wired or wireless communication links 191 - 193.

[0019] User device The user device 105 can be a computer device such as a smartphone, a smartwatch, a tablet, a personal diabetes management (PDM) device, a dedicated diabetes treatment management device, etc. For example, the user device 105 can have a processor 151, a device memory 153, a user interface 158, and a communication interface 154. The user device 105 can also execute processing based on program code stored in the device memory 153, such as a user application 160, to manage the user's blood glucose level and control the delivery of drugs, medications, or therapeutic agents to the user, and can also provide other functions, such as calculations of carbohydrate compensation amounts, correction bolus amounts, etc., to be executed as the processor 151 and can include analog and / or digital circuitry. The user device 105 can be used for the operation, non - operation, triggering, needle / cannula insertion, programming, adjustment of settings, and / or control actions of the drug delivery device 102 and / or the sample sensor 103 and any optional smart accessory device 106.

[0020] Furthermore, the processor 151 may be configured to execute programming code stored in the device memory 153, such as a user application 160. The user application 160 may be a computer application capable of operating to deliver medication based on information received from the sample sensor 103, the cloud-based service 111, and / or the user device 105 or an optional accessory device 106. The memory 153 may also store programming code for operating a user interface 158 (e.g., a touchscreen device, a camera, etc.), a communication interface 154, etc. When the user application 160 is executed, the processor 151 may be configured to provide indicators and notifications regarding food intake, blood glucose measurement, etc. The user interface 158 is under the control of the processor 151 and may be configured to present a graphical user interface, such as enabling input of meal announcements and adjusting setting selections, as described herein.

[0021] In a specific example, if the user application 160 is for an artificial pancreas (AP) application, the processor 151 is also configured to execute a diabetes treatment plan managed by the user application 160 (which may be stored in memory). In addition to the functions described above, when the user application 160 is for an artificial pancreas (AP) application, it may further provide functionality to determine carbohydrate compensation doses, corrected bolus doses, and real-time basal doses according to the diabetes treatment plan. Furthermore, as an artificial pancreas (AP) application, the user application 160 provides the function of outputting signals to the drug delivery device 102 via the communication interface 154 to deliver the determined bolus and basal doses.

[0022] The communication interface 154 has one or more transceivers operating according to one or more radio frequency protocols. In one embodiment, the transceivers may include cellular transceivers and Bluetooth® transceivers. The communication interface 154 may be configured to receive and transmit signals containing information usable by the user application 160.

[0023] The user device 105 may further include one or more output devices 155, which can be, for example, speakers or vibration transducers, to provide the user with various signals.

[0024] Drug delivery device In various exemplary embodiments, the drug delivery device 102 may have a reservoir 124 and a drive mechanism 125 controllable by a control unit 121, which can execute a drug delivery algorithm (MDA) 129 stored in memory 123 and perform some or all of the functions of the AP application described above, thereby making it unnecessary for the user device 105 to have the drug delivery device 102 perform drug delivery and control. Alternatively, the control unit 121 may act to control the reservoir 124 and the drive mechanism 125 based on signals received from a user application 160 running on the user device 105 and communicated to the drug delivery device 102 via a communication line 194. The drive mechanism 125 operates to move a plunger longitudinally through the reservoir to force liquid drug through a fluid discharge port into the needle / cannula 186.

[0025] In alternative embodiments, the drug delivery device 102 may also have an optional second reservoir 124-2 and a second drive mechanism 125-2, enabling independent delivery of two different liquid drugs. For example, reservoir 124 may be filled with insulin and reservoir 124-2 may be filled with Plumlintide or GLP-1. In some embodiments, each of reservoirs 124, 124-2 may be configured with a separate drive mechanism 125, 125-2, which can be independently controlled by the control unit 121 under the direction of the MDA 129. Both reservoirs 124, 124-2 may be connected to a common needle / cannula 186.

[0026] The drug delivery device 102 may optionally be configured to include a user interface 127 that provides means for receiving input from the user and means for outputting information to the user. The user interface 127 may have, for example, a light-emitting diode, a button on the housing of the drug delivery device 102, an acoustic transducer, a microdisplay, a microphone, an accelerometer for detecting the movement of the device or the user's gestures (e.g., tapping the housing of the device), or any other type of interface device configured to allow the user to input information and / or to allow the drug delivery device 102 to output information to present to the user (e.g., an alarm signal).

[0027] The drug delivery device 102 has a patient interface 186 for adapting to a user to deliver a liquid drug. The patient interface may be, for example, a needle or cannula for delivering the drug to the user's body (this delivery may be subcutaneous, intraperitoneal, or intravenous). The drug delivery device 102 further has a mechanism for inserting the needle / cannula 186 into the user's body, which may be integrated with or attachable to the drug delivery device 102. In one embodiment, the insertion mechanism may include an actuator that inserts the needle / cannula 186 under the user's skin, then retracts the needle, leaving the cannula in place. The actuator may be triggered by a user device 105, or it may be a manual firing mechanism with a spring or other energy storage mechanism for penetrating the user's skin with the needle / cannula 186.

[0028] In one embodiment, the drug delivery device 102 has a communication interface 126, which may be a transceiver operating according to one or more radio frequency protocols such as Bluetooth®, Wi-Fi®, near-field communication, or cellular. The control unit 121 can communicate with the user device 105 and the sample sensor 108, for example, via the communication interface 126.

[0029] In some embodiments, the drug delivery device 102 may include one or more sensors 184. The sensors 184 have one or more of the following, such as pressure sensors and power sensors, which are communicatively connected to the control unit 121 and provide various signals. For example, a pressure sensor may be configured to provide an index of fluid pressure detected in the fluid path between the patient interface 186 and the reservoir 124. The pressure sensor may be connected to or integrated with an actuator for inserting the patient interface 186 into the user. In one example, the control unit 121 may be operable to determine the drug infusion rate based on the fluid pressure index. The drug infusion rate may be compared to an infusion rate threshold, and the result of this comparison may be used when determining the amount of insulin loaded (IOB) or total daily insulin (TDI) amount. In one embodiment, a sample sensor 108 may be integrated with the drug delivery device 102.

[0030] The drug delivery device 102 further includes a power source 128, such as a battery, for supplying power to the control unit 121, memory 123, drive mechanism 125, and / or other components of the drug delivery device 102, as well as a piezoelectric device, an energy harvesting device, and the like.

[0031] The drug delivery device 102 may be configured to perform and execute the processing required to deliver multiple doses of drug to the user without input from the user device 105 or an optional accessory device 106. As will be described in more detail, the MDA 129 may be operable to determine, for example, the amount of insulin to be delivered, IOB, remaining insulin, etc., and to actuate the control unit 121 to the drive mechanism 125 to deliver the drug from the reservoir 124. The MDA 129 can be acquired as input data received from the sample sensor 108 or the user application 160.

[0032] Reservoirs 124 and 124-2 may be configured to store drugs, medications, or therapeutic agents suitable for automated delivery, such as insulin, pramulintide, GLP-1, insulin and GLP-1 co-formulations, morphine, blood pressure medications, chemotherapy drugs, and reproductive drugs.

[0033] The drug delivery device 102 can be a wearable device that can be attached to the body of a patient or a user such as a diabetic patient at an attachment point, and can deliver any drug or therapeutic agent, including insulin, to the user at or around the attachment point. The surface of the drug delivery device 102 may have an adhesive to facilitate attachment to the user's skin.

[0034] When the drug delivery device 102 is configured to communicate with an external device such as a user device 105 or a sample sensor 108, the drug delivery device 102 can receive signals from the user device 105 or the sample sensor 108 via a wired or wireless link 194. The control unit 121 of the drug delivery device 102 can receive and process signals from each external device and deliver drugs to the user according to a diabetes treatment plan or other drug delivery plan.

[0035] Accessory devices The optional accessory device 107 may be a wearable smart device, such as a smartwatch (e.g., Apple Watch®), smart glasses, smart jewelry, a wearable fitness device with Global Positioning System (GPS) capabilities, or smart clothing. Similar to the user device 105, the accessory device 107 may also be configured to perform various functions, including controlling the drug delivery device 102. For example, the accessory device 107 may have a communication interface 174, a processor 171, a user interface 178, and memory 173. The user interface 178 may be a graphical user interface presented on the touchscreen display of the smart accessory device 107. The memory 173 can store programming code for operating the various functions of the smart accessory device 107, as well as instances of the user application 160, or a simplified version of the user application 160 with reduced functionality. In some examples, the accessory device 107 may also have various types of sensors.

[0036] Sample sensor The sample sensor 108 may include a control unit 131, a memory 132, a detection / measurement device 133, an optional user interface 137, a power supply / energy harvesting circuit 134, and a communication interface 135. The sample sensor 108 may be communicatively connected to the management device 105 of the drug delivery device 102 or the processor 151 of the control unit 121. The memory 132 may be configured to store information and programming code 136.

[0037] The sample sensor 108 may be configured to detect one or more different samples, such as glucose, lactate, ketones, uric acid, sodium, potassium, or alcohol levels, and to output detection results, such as measured values. In exemplary embodiments, the sample sensor 108 may be configured as a continuous glucose monitor (CGM) for measuring blood glucose levels at predetermined time intervals, such as every 5 minutes or every minute. The communication interface 135 of the sample sensor 108 may have a circuit that operates as a transceiver for communicating measured blood glucose levels to a user device 105 via a wireless link 195, or to a drug delivery device 102 via a wireless communication link 108. Although referred to herein as the sample sensor 108, the detection / measurement device 133 of the sample sensor 108 may have one or more additional detection elements, such as a glucose measuring element, a heart rate monitor, or a pressure sensor. The control unit 131 has a microcontroller or processor that executes separate dedicated logic and / or components, application-specific integrated circuits, and software instructions, firmware, programming instructions stored in memory (such as memory 132), or any combination thereof.

[0038] Similar to the control unit 121 of the drug delivery device 102, the control unit 131 of the sample sensor 108 can be configured to perform many functions. For example, the control unit 131 may be configured by programming code 136 to manage the collection and analysis of data detected by the detection and measurement device 133.

[0039] Although the sample sensor 108 is shown separately from the drug delivery device 102 in Figure 1, in various embodiments, the sample sensor 108 and the drug delivery device 102 may be integrated into the same unit. That is, in various embodiments, the sample sensor 108 may be integrated with the drug delivery device 102 as part of it, and may be contained within the same housing as the drug delivery device 102 or in a housing that can be attached to it. In such exemplary configurations, the control unit 121 can independently perform the functions required for proper drug delivery without any external input from the user device 105, the cloud-based service 111, another sensor (not shown), or an optional accessory device 106.

[0040] Cloud-based services The drug delivery system 100 can communicate with or receive services from a cloud-based service 111. The services provided by the cloud-based service 111 may have a data memory that stores personalized or anonymized data, such as blood glucose measurements, past IOB or TDI, prior carbohydrate compensation doses, and other forms of data. Furthermore, the cloud-based service 111 can process anonymized information from a large number of users to provide generalized information related to TDI, insulin sensitivity, IOB, etc. The communication links 115 connecting the cloud-based service 111 to each device 102, 105, 106, 108 of the system 100 may be a cellular link, a Wi-Fi® link, a Bluetooth® link, or a combination thereof.

[0041] Communication link Wireless communication links 115 and 191-196 can be any type of wireless link operating using known or proprietary wireless communication standards. For example, wireless communication links 191-196 may provide communication links based on Bluetooth®, Zigbee®, Wi-Fi®, short-range communication standards, cellular standards, or any other wireless protocol via their respective communication interfaces 126, 135, 154, and 174.

[0042] Example of operation In the operational example, the user application 160, which is used to program the startup and shutdown of the drug delivery device 102, the base and bolus computer settings for manual mode, and the settings specific to automatic mode (hybrid closed-loop or closed-loop), implements a graphical user interface, which is the primary interface with the user.

[0043] The user application 160 provides a graphical user interface 158 that enables the use of large characters, graphics, and on-screen instructions to prompt the user throughout the setup process and the use of the system 100. It is also used to program the user's customized basal insulin delivery profile, check the status of the drug delivery device 102, initiate insulin bolus administration, modify the patient's insulin delivery profile, handle system alerts and alarms, and allow the user to switch between automatic and manual modes.

[0044] The user application 160 may be configured to operate in manual mode, with the option to set a provisional baseline profile, to deliver insulin at a programmed baseline rate and a user-defined bolus volume. The control unit 121 also has the capability to function as a sensor expansion pump in manual mode, using sensor glucose data provided by the sample sensor 108 to feed into the bolus calculator.

[0045] The user application 160 may be configured to operate in an automated mode that assists in the use of multiple target blood glucose levels. For example, in one embodiment, the target blood glucose levels may be in the range of 110 mg / dL to 150 mg / dL, increments of 10 mg / dL, increments of 5 mg / dL, or other increments, preferably increments of 10 mg / dL. The user experience reflects the current setup flow, thereby assisting the healthcare provider in programming the basal rate, glucose target, and bolus calculator setup. These inform the user application 160 about insulin administration parameters. The insulin administration parameters are adapted over time based on the total daily insulin (TDI) delivered during each use of the drug delivery device 102. A pseudo-hypoglycemic protection mode may be implemented by the user during various durations in automated mode. In hypoglycemic protection mode, the algorithm is intended to be used over pseudo-durations when insulin delivery is reduced and higher insulin sensitivity is expected (e.g., during exercise).

[0046] User application 160 (or MDA 129) may provide periodic insulin microboluses over a predicted period (e.g., 60 minutes) based on past glucose measurements and / or predicted glucose levels. Optimal postprandial control may require the user to administer meal boluses in the same manner as current pump therapy, but the normal operation of user application 160 compensates for any meal boluses that are not administered, mitigating prolonged hyperglycemia. User application 160 employs a control-versus-target strategy that attempts to achieve and maintain set target blood glucose levels, thereby reducing the duration of prolonged hyperglycemia and hypoglycemia.

[0047] In some embodiments, the user device 105 and the sample sensor 108 do not need to communicate directly with each other. Instead, data from the sample sensor (e.g., blood glucose level) may be transmitted to the drug delivery device 102 via link 196 and then relayed to the user device 105 via link 194. In some embodiments, the serial number of the sample sensor must be entered into the user application 160 to enable communication between the sample sensor 108 and the user device 105.

[0048] User application 160 can provide the ability to calculate a proposed bolus dose through the use of a bolus calculator. The bolus cube calculator is provided for the user's convenience to help determine a proposed bolus dose based on ingested carbohydrates, the most recent blood glucose measurement (or a fingertip measurement), a programmable correction factor, the insulin-to-carbohydrate ratio, the target blood glucose level, and the onboard insulin (IOB). User application 160 estimates the IOB, taking into account manual boluses and insulin.

[0049] Description of the Embodiment A primary embodiment of the present invention is schematically shown in Figures 3A to 3C. Figure 3A shows a dual reservoir in an empty configuration, in which the inner reservoir 304 is linearly moved throughout into the outer reservoir 302. The outer reservoir 302 is fixed to the housing of the drug delivery device 102, and the inner reservoir 304 can be linearly moved in and out of the outer reservoir 302 using an external or internal drive mechanism. A static plunger 306 is fixed to the outer reservoir 302 via a hollow tube 308.

[0050] Figure 3A shows a hollow tube 308 rigidly attached to the central portion of the back wall of the outer reservoir 302. The hollow tube 308 defines fluid ports 314, 316 at either end, so that fluid in the outer reservoir 302 can be pushed through the hollow tube 308 into the inner reservoir 304. A static plunger 306 is located inside the inner reservoir 304 and acts to push fluid out of the inner reservoir 304 through the fluid port 310 as the inner reservoir 304 moves into the outer reservoir 302.

[0051] Preferably, there is a fluid seal 318 defined around the outer surface of the inner reservoir 304 to form a fluid seal between the outer surface of the inner reservoir 302 and the inner surface of the outer reservoir 304, so as to prevent any fluid contained in the outer reservoir 302 from leaking to the outside. Similarly, the static plunger 306 is configured with a fluid seal around its outer circumference to form a seal between the plunger 306 and the inner wall of the inner reservoir 304, so as to contain fluid in the inner reservoir 304. An additional seal (not shown) may be provided between the static plunger 306 and the hollow tube 308 to prevent leakage between the inner reservoir 304 and the outer reservoir 302, and between the hollow tube 308 and the end wall of the inner reservoir 304, which acts as a plunger when the inner reservoir 304 moves into the outer reservoir 302 in direction "B".

[0052] Figure 3B illustrates the process of filling the dual reservoirs 302, 304. Adding fluid to the system through a fluid port 312 defined within the end wall of the outer reservoir 302 results in an increase in pressure inside the outer reservoir 302. The hollow tube 308 fluidically connects the outer reservoir 302 to the inner reservoir 304, so the fluid moves from the outer reservoir 302 to the inner reservoir 304 through the hollow tube 308, causing an increase in pressure inside the inner reservoir 304. Note that the hollow tube 308 extends through a static plunger 306 to allow the fluid to enter the sealed end of the inner reservoir 304. As the reservoirs continue to fill, the fluid pressure generated inside both reservoirs overcomes system friction, causing the inner reservoir 304 to begin moving in direction "A," and exiting the outer reservoir 302 until the end wall of the inner reservoir 304 contacts the static plunger 306, reaching the fully filled configuration shown in Figure 3C. In an alternative embodiment, reservoirs 302 and 304 may be separated at the positions shown in Figure 3C before filling, and then filled while separated. In this case, filling the reservoirs does not bias the inner reservoir 304 in direction "A." When a user inserts a liquid agent into either or both of reservoirs 302 and 304, air is pushed out.

[0053] From the fully filled configuration shown in Figure 3C, the fluid contained in both reservoirs can then be supplied. Figure 3D illustrates the process of supplying the fluid. The inner reservoir 304 moves linearly into the outer reservoir 302 in a manner controlled by an external driving force, which causes the inner reservoir 304 to move linearly in direction "B" into the outer reservoir 302. Several exemplary drive mechanisms that provide the external driving force are disclosed herein. Pushing the inner reservoir 304 into the outer reservoir 302 reduces the available volume in both reservoirs 302,304 and pressurizes the contained fluid. When the fluid pressure exceeds the applied back pressure, the fluid exits the pump mechanism through the fluid discharge port 310 and is defined on the wall of the inner reservoir 304. The supply of fluid continues until both reservoirs reach the empty configuration shown in Figure 3A when the end wall of the inner reservoir 304 contacts the end wall of the outer reservoir 302.

[0054] The positions of both the fluid filling port 312 and the fluid discharge port 310 are flexible so that they can be located on either the inner reservoir 304 or the outer reservoir 302. The option that best suits the system requirements can be selected for implementation. For example, having the fluid ports on the movable inner reservoir 304 may create challenges regarding the integration of the pump system with other subsystems of the drug delivery device 102. In various embodiments, either the fluid ports 310, 312 may function as the inlet fluid port of the fluid discharge port. In such cases, it may be necessary to seal the fluid port acting as a discharge port during reservoir filling and the fluid port acting as an inlet port during fluid supply. In some embodiments, the pump mechanism may be configured to have only one of the fluid ports 310, 312 that acts as both an inlet fluid port and a fluid discharge port.

[0055] As described above, precise fluid supply requires precisely controlled movement of the inner reservoir 304 into the outer reservoir 302. In some embodiments, a clutch may be provided between the drive mechanism and the reservoir to which the drive mechanism is connected. This allows the drive mechanism to be disengaged from the reservoir for the user to fill the reservoir (for example, moving in the opposite direction from its movement during the supply process when the reservoir is needed during the filling process). Once filling is complete, the clutch can be engaged to connect the drive mechanism to the reservoir, and then fluid can be supplied through the operation of the drive mechanism. Hereinafter, several modifications of the primary embodiment featuring different drive mechanisms are disclosed.

[0056] Figures 4A and 4B show a first extension of a primary embodiment in which the inner reservoir 304 is linearly moved into the outer reservoir 302 using a lead screw 406. The lead screw 406 is attached to the inner reservoir 304 as shown in Figure 4A. Overmolding, heat sticking, or adhesive can be used to ensure a secure connection between the lead screw 406 and the inner reservoir 304. A tube nut 404, which is an elongated tube with a female thread for the lead screw 406, engages with the end of the lead screw 406 opposite to the end that engages with the inner reservoir 304. The pumping action is produced by rotating the tube nut 404 in direction "D", as shown in Figure 4B, which results in linearly moving the inner reservoir 304 in direction "E" into the outer reservoir 302. Since the axial movement of the tube nut 404 is restricted, the rotation of the tube nut 404 causes axial movement of the lead screw 406 and the inner reservoir 304 through the threading between the lead screw 406 and the tube nut 404.

[0057] Figures 4A to 4B also show a fluid seal 402 that extends around the outer circumference of the moving plunger 307 and forms a fluid seal between the outer surface of the inner reservoir 304 and the inner surface of the outer reservoir 302. The fluid seal 402 prevents the fluid contained in the outer reservoir 302 from escaping through the space between the outer reservoir 302 and the inner reservoir 304. Figures 4A to 4B also show that the plunger 306 is fitted with an O-ring around its outer circumference to form a fluid seal between the plunger 306 and the inner surface of the inner reservoir 304 to prevent the fluid contained in the inner reservoir 304 from escaping. Furthermore, a fluid seal (not shown) may be provided between the hollow tube 308 and the moving plunger 307 to prevent leakage between the inner reservoir 304 and the outer reservoir 302.

[0058] Figures 5A to 5C show a second extension of the primary embodiment in which the lead screw 510 is screwed into the push member 502 through a threaded through-hole 506 defined within the push member 502. When the lead screw 510 rotates, the push member 502 moves axially along the lead screw 510, but the push is centered on the axis of the lead screw 510. component The rotation of 502 is restricted. Figure 5A shows the initial state in which neither reservoir is filled. Reservoir 304 does not contact the push member 502 in the initial unfilled state. When reservoirs 302 and 304 are filled, the inner reservoir 304 moves in direction "F" and eventually engages with the push member 502, as shown in Figure 5B. Note that reservoir 304 moves in direction "F" due to the pressure generated by the filling of reservoirs 302 and 304, and not due to the action of the lead screw 510 or the movement of the push member 508. When reservoirs 302 and 304 are filled as shown in Figure 5B, the action of the lead screw 510 causes the inner reservoir 304 to move in direction "E", as shown in Figure 5C.

[0059] The lead screw 510 can be rotated by any known means. For example, the pipe nut 404 shown in Figures 4A-4B can also be used in this modification, either alternatively or additionally, by a motor. Rotation of the lead screw 510 in direction "D" results in linear movement of the push member 502 in direction "E" along the longitudinal axis of the lead screw 510. In some embodiments, the push member 502 may be configured with a protruding feature 504 that engages with a recess 508 defined on the outside of the end wall of the inner reservoir 304. In some embodiments, the protruding feature 504 may be hemispherical in shape, and the recess 508 may be concave, or vice versa. In yet other embodiments, any other type of engagement between the push member 502 and the outside of the end wall of the inner reservoir 304 may be used. When the push member 502 moves linearly in direction "E" due to the rotation of the lead screw 510 in direction "D", the push member 502 engages with the outer end wall of the inner reservoir 304, moving the inner reservoir 304 into the outer reservoir 302 in direction "E". A significant advantage of this embodiment compared to the embodiments shown in Figures 4A and 4B is that no off-axial load is applied to the inner reservoir 304. Therefore, the inner reservoir 304 always remains coaxially aligned with the outer reservoir 302.

[0060] Figures 6A to 6B show a third extension of the primary embodiment in which the push member 502 of the extension shown in Figures 5A to 5B is integrated with the body of the inner reservoir 304 indicated by reference numeral 602. In the modified example shown in Figure 6A, the push member 602 is also integrated with the fluid port 310, but it should be noted that, as can be understood, the push member 602 may be defined on the inner reservoir 304, separate from the fluid port 310. The push member 602 defines a through hole 604 having a female thread. The push member 602 is screwed to the lead screw 510 such that rotation of the lead screw 510 in direction "D" results in controlled linear movement of the inner reservoir 304 into the outer reservoir 302 in direction "E". Similar to the embodiments described above, the lead screw 510 may be rotated via a pipe nut of the type shown in Figures 4A-4B as reference number 404, or by any other known means.

[0061] Figures 7A and 7B show a fourth extension of the primary embodiment. In this embodiment, the inner reservoir 304 is preferably firmly attached to the housing of the drug delivery device 102, and the outer reservoir 302 moves linearly so as to cover and move over the inner reservoir 304, thereby moving the inner reservoir 304 linearly into the outer reservoir 302. In this modification, the drive mechanism is a rack and pinion configuration. The outer reservoir 302 is configured to have a rack gear 702 on its outer surface. The pinion gear 704 is rotated in direction "F" by any known means, moving the outer reservoir 302 in direction "F", thereby moving the inner reservoir 304 linearly into the outer reservoir 302 by the linear motion of the outer reservoir 302 in direction "F".

[0062] The lead screw / tube nut mechanism shown in the modified versions in Figures 4-6 provides precisely controlled axial displacement of the internal reservoir 304 and introduces mechanical advantages to the system. However, a limitation not present in this modified version is that it can reduce the energy efficiency of the system due to further friction caused by extraaxial loads between the lead screw thread and the tube nut thread.

[0063] Figures 8A and 8B show a fifth extension of the primary embodiment. The lead screws are not a perfect mechanism against off-axis loads, as frictional losses increase sharply as off-axis loads are applied to the system. To minimize the effect of off-axis loads on the lead screws, this modification uses two lead screws 802 and 804. The lead screws 802 and 804 are screwed into a press member 602 of the type shown in Figures 6A and 6B, the press member 602 is integral with the inner reservoir 304 and is positioned on both sides of the inner reservoir 304. Thus, the synchronous rotation of the lead screws 802 and 804 in direction "D" causes the reservoir 304 to move linearly in direction "E", thereby driving the reservoir into the outer reservoir 302. The lead screws 802 and 804 can be rotated using a pipe nut of the type shown in Figures 4A and 4B as reference number 404 or any other known means. A modification (not shown) for using two lead screws involves using a lead screw on one side and a smooth cylindrical rod on the other side, through which one of several push members 602 slides. In this way, only one lead screw needs to be rotated, while still overcoming the challenge of off-axis loading.

[0064] By using a double lead screw, the system's energy efficiency is increased not only by minimizing or eliminating the off-axis moment applied to the lead screw / tube nut interface, but also by improving the alignment between the inner reservoir 304 and the outer reservoir 302. Variations using two lead screws (or one lead screw and a smooth cylindrical rod) can be applied to any of the modifications of the present invention shown in Figures 4 to 6 above. With respect to the embodiments shown in Figures 7A to 7B, the double rack and pinion mechanism can be used in the same manner as the double lead screw modifications and can achieve the same results.

[0065] Figure 9 schematically shows a secondary embodiment of the present invention using a dual reservoir configuration with central actuation. As discussed with respect to the earlier embodiments and modifications, lateral actuation has drawbacks such as misalignment between the inner reservoir 304 and the outer reservoir 302, and further friction loss at the lead screw / tube nut interface. The embodiment shown in Figure 9 overcomes these drawbacks by using a central actuation mechanism in which the lead screw 902 is located inside the inner reservoir 304 and in contact with the end wall of the inner reservoir 304. In this way, the lead screw 902 is positioned coaxially with the reservoirs 302, 304. In this case, the load is aligned with the desired direction of motion of the inner reservoir 304, preventing misalignment between the reservoirs 302, 304 and reducing friction loss in the lead screw 902.

[0066] Figure 9 is a schematic diagram of an embodiment of a dual reservoir with central action, in which a lead screw 902 having a male thread is screwed into a tube nut 904 having a female thread. A plunger tube 908 is firmly attached to the housing of the drug delivery device 102 and supports a static plunger 906. In this embodiment, the outer reservoir 302 is also firmly attached to the housing of the drug delivery device 102, and the tube nut 904 rotates freely in direction "C" about its longitudinal axis, but is restricted from moving axially. The lead screw 902 is moved axially by its screwing with the tube nut 904 in order to push the inner reservoir 304 into the outer reservoir 302 by the engagement of the lead screw 902 with the end wall of the inner reservoir 304. In this embodiment, the interfaces between the inner reservoir 304 and the outer reservoir 302, the interface between the static plunger 906 and the inner reservoir 304, and the interface between the inner reservoir 304 and the plunger tube 908 are fluidically sealed by means described above for other modifications. Note that in this embodiment, since fluid movement between the inner reservoir 304 and the outer reservoir 302 is prevented, each of the inner reservoir 304 and the outer reservoir 302 must have its own fluid port. The connection of the respective fluid ports from the inner reservoir 304 and the outer reservoir 302 is made outside the pump mechanism at any convenient location between the pump mechanism and the patient interface.

[0067] Figures 10A and 10B show cross-sections of this embodiment of the present invention. Due to the screwing between the lead screw 902 and the pipe nut 904, the rotation of the pipe nut 904 moves the lead screw 902 in direction "E", pushing it against the end wall of the inner reservoir 304, thereby moving the inner reservoir 304 into the outer reservoir 302.

[0068] Exemplary embodiments of the present invention disclosed herein present a reservoir having a circular cross-sectional shape. However, the present invention is not limited thereto. Alternative embodiments may use reservoirs having different cross-sectional shapes, examples of which are shown in Figures 11A to 11C. In the primary embodiment, the reservoir may have a circular cross-sectional shape, but other cross-sectional shapes such as a rectangle with rounded edges (Figure 11A), a flattened circle (Figure 11B), or an ellipse (Figure 11C) can be implemented without departing from the intended technical scope of the present invention. While a rectangular cross-sectional shape may offer increased volumetric efficiency over a circular cross-sectional shape, a rectangular cross-sectional shape also increases the risk of seal failure due to sharper corners. Ideally, a combination of rectangular and elliptical shapes, as shown in Figures 11A to 11C, may be a preferred choice for achieving both reasonable sealing quality and volumetric efficiency.

[0069] As described with respect to the embodiments and modifications disclosed herein, several interfaces, such as the interface between the inner reservoir 304 and the outer reservoir 302, need to be sealed in order to achieve the expected performance of the pump mechanism. In these cases, O-rings can be used, as shown in Figure 12A, which can be placed in a groove defined on the circumferential surface of the plunger 306 to maintain a dynamic seal between the plunger 306 and the inner surface of the inner reservoir 304. Alternatively, as shown in Figure 12B, two-shot molding techniques can be used to bond a silicone rubber sealing element to the plunger 306. Two-shot molding simplifies the assembly process.

[0070] The following embodiments relate to various embodiments of the systems and methods disclosed herein for the implementation of an automated drug delivery system having a dual reservoir pump mechanism.

[0071] Embodiment 1 is a first embodiment of a pump mechanism comprising an outer reservoir and an inner reservoir configured to move linearly in and out of the outer reservoir, the first embodiment of the pump mechanism comprising a static plunger disposed inside the inner reservoir, a hollow tube supporting the static plunger that fluidly connects the inner reservoir and the outer reservoir, one or more fluid ports, and a drive mechanism for moving the inner reservoir linearly into the outer reservoir.

[0072] Example 2 is an extension of Example 1, or any other example disclosed herein, wherein the pump mechanism further comprises a fluid seal between the inner reservoir and the outer reservoir.

[0073] Example 3 is an extension of Example 1, or any other example disclosed herein, in which the external reservoir is firmly attached to the external structure of the pump mechanism.

[0074] Embodiment 4 is an extension of Embodiment 3, or any other embodiment disclosed herein, wherein the inner reservoir defines a through hole, and the drive mechanism comprises a lead screw that engages with the through hole such that the linear translation of the lead screw causes the inner reservoir to move linearly into the outer reservoir.

[0075] Embodiment 5 is an extension of Embodiment 4, or any other embodiment disclosed herein, wherein the drive mechanism further comprises a pipe nut that screws onto a lead screw, such that the rotation of the pipe nut causes the lead screw to move linearly.

[0076] Embodiment 6 is an extension of Embodiment 1, or any other embodiment disclosed herein, wherein the outer surface of the inner reservoir defines a recess, and the drive mechanism comprises a push member defining a female screw portion and a protrusion having a through hole, and a lead screw that screws into the through hole of the push member, and the rotation of the lead screw causes linear parallel movement of the push member, engaging the recess and protrusion on the inner reservoir and pushing the inner reservoir into the outer reservoir.

[0077] Example 7 is an extension of Example 6, or any other example disclosed herein, in which the projection is hemispherical in shape and the recess is concave.

[0078] Example 8 shows a drive mechanism that is integrated with an inner reservoir and defines a through hole having a female threaded portion. component Then, the rotation of the lead screw is pushed in component An extension of Embodiment 1, or any other embodiment disclosed herein, comprising a lead screw that engages with a through hole to cause linear movement of the inner reservoir into the outer reservoir.

[0079] Embodiment 9 is an extension of Embodiment 1, or any other embodiment disclosed herein, wherein the drive mechanism comprises a rack gear positioned on the outer surface of the outer reservoir and a pinion gear engaged with the rack gear such that the rotation of the pinion gear causes linear movement of the outer reservoir toward the end of the outer reservoir.

[0080] Example 10 is an extension of Example 7, or any other example disclosed herein, wherein the inner reservoir defines a second through-hole located on the outer surface of the inner reservoir opposite to the through-hole, and the drive mechanism further comprises a second lead screw that engages with the second through-hole such that the linear movement of the inner reservoir into the outer reservoir occurs by the synchronous linear movement of the lead screw and the second lead screw.

[0081] Example 11 shows a second push mechanism in which the drive mechanism is integrated with an inner reservoir that defines a through hole having a female thread portion. component And, the second push component An extension of Example 8, or any other embodiment disclosed herein, further comprising a second lead screw that engages with a through hole, wherein synchronous rotation of the lead screw causes the inner reservoir to move linearly into the outer reservoir.

[0082] Embodiment 12 is an extension of Embodiment 9, or any other embodiment disclosed herein, wherein the drive mechanism further comprises a second rack gear positioned on the outer surface of the outer reservoir opposite to the rack gear, and a second pinion gear that engages with the second rack gear such that the synchronous rotation of the pinion gear causes the outer reservoir to move linearly toward the inner reservoir.

[0083] Example 13 is an extension of Example 1, or any other example disclosed herein, wherein the inner and outer reservoirs have cross-sectional shapes selected from the group consisting of elliptical, flattened circular, and rectangles with rounded corners.

[0084] Example 14 is an extension of Example 1, or any other example disclosed herein, wherein the pump mechanism further comprises a fluid seal positioned on the circumferential surface of a static plunger so as to create a fluid seal between the plunger and the inner surface of the inner reservoir.

[0085] Example 15 is an extension of Example 1, or any other example disclosed herein, wherein the pump mechanism further comprises a fluid seal between the inner surface of the outer reservoir and the outer surface of the inner reservoir.

[0086] Example 16 is an extension of Example 1, or any other example disclosed herein, wherein the pump mechanism further comprises a fluid seal between the hollow tubes in the static plunger.

[0087] Embodiment 17 is a pump mechanism of a second embodiment, comprising an outer reservoir, an inner reservoir configured to move linearly in and out of the outer reservoir, a static plunger located inside the inner reservoir, and a lead screw located inside the inner reservoir coaxially with the longitudinal axis of the inner reservoir, the lead screw extending through the static plunger so as to contact the end wall of the inner reservoir and the pipe nut engaged with the lead screw, such that rotation of the pipe nut causes linear movement of the lead screw that pushes the inner reservoir into the outer reservoir.

[0088] Example 18 is an extension of Example 17, or any other example disclosed herein, in which the outer reservoir is firmly attached to the external structure of the pump mechanism.

[0089] Example 19 is an extension of Example 18, or any other example disclosed herein, in which the pump mechanism further comprises a hollow tube including a pipe nut, the hollow tube being firmly attached to an external structure of the pump mechanism and supporting a static plunger.

[0090] Example 20 is an extension of Example 19, or any other example disclosed herein, wherein the pump mechanism further comprises a drive mechanism for rotating a pipe nut.

[0091] Example 21 is an extension of Example 20, or any other example disclosed herein, wherein the pump mechanism further comprises a first fluid port defined in the wall of an outer reservoir and a second fluid port defined in the wall of an inner reservoir.

[0092] Example 22 is an extension of Example 21, or any other example disclosed herein, in which the first fluid port and the second fluid port are fluidically connected outside the pump mechanism.

[0093] Example 23 is an extension of Example 17, or any other example disclosed herein, wherein the pump mechanism further comprises a fluid seal positioned on the circumferential surface of a static plunger so as to form a fluid seal between the plunger and the inner surface of an inner reservoir.

[0094] Example 24 is an extension of Example 17, or any other example disclosed herein, wherein the pump mechanism further comprises a fluid seal between the inner reservoir and the outer reservoir.

[0095] Example 25 is an extension of Example 17, or any other example disclosed herein, wherein the inner and outer reservoirs have cross-sectional shapes selected from the group consisting of elliptical, flattened circular, and rectangles with rounded corners.

[0096] Example 26 is a third embodiment of a pump mechanism comprising an outer reservoir, an inner reservoir configured to move linearly within the outer reservoir, and a drive mechanism for moving the inner reservoir linearly, wherein a portion of the inner reservoir acts as a plunger within the outer reservoir to push out a drug contained within the outer reservoir through a first fluid port.

[0097] Software-related implementations of the technologies described herein may include, but are not limited to, firmware, application-specific software, or any other type of computer-readable instruction that can be executed by one or more processors. Computer-readable instructions may be provided via a non-temporary computer-readable medium. Hardware-related implementations of the technologies described herein include, but are not limited to, integrated circuits (ICs), application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), and / or programmable logic devices (PLDs). In some examples, the technologies described herein, and / or any systems or components described herein, may be executed using processors that execute computer-readable instructions stored on one or more memory components.

[0098] Many modifications and adaptations of the present invention will be understood by those skilled in the art in which the present invention relates. The embodiments provided herein, including descriptions of the dimensions, shapes, ratings and specifications of various components or arrangements of components, and specific manufacturing processes, are illustrative and not intended to limit the present invention. As those skilled in the art will understand, many variations of the forms discussed herein that fall within the scope of the present invention are possible. Furthermore, it should be understood that the features of the various embodiments described herein are not mutually exclusive and may exist in various combinations and substitutions, even if such combinations or substitutions are not expressly expressed herein, without departing from the spirit and scope of the present invention. Accordingly, the methods and apparatus disclosed herein should be construed as illustrative examples and not as limiting the present invention. The scope of the present invention is defined by the following claims. Furthermore, this disclosure includes the following inventions. The first aspect is, In a pump mechanism, The aforementioned pump mechanism is Outer reservoir and, An inner reservoir configured to move linearly within the outer reservoir, A static plunger is located inside the aforementioned inner reservoir, A hollow tube supporting the static plunger and extending between the inner reservoir and the outer reservoir, thereby fluidly connecting the inner reservoir to the outer reservoir, One or more fluid ports defined in either or both of the inner reservoir and the outer reservoir, The pump mechanism includes a drive mechanism for linearly moving the inner reservoir into the outer reservoir. The second aspect is, The aforementioned pump mechanism is The pump mechanism in the first embodiment further comprises a fluid seal between the inner surface of the outer reservoir and the outer surface of the inner reservoir. The third aspect is, The external reservoir is a pump mechanism in a first embodiment, which is firmly attached to the external structure of the pump mechanism. The fourth aspect is, The portion attached to the inner reservoir defines a through hole, The drive mechanism is a pump mechanism in a first embodiment, comprising a lead screw that engages with a through hole such that the linear translation of the lead screw causes the inner reservoir to move linearly into the outer reservoir. The fifth aspect is, The pump mechanism in the fourth embodiment further comprises a pipe nut that screws onto the lead screw, such that the rotation of the pipe nut causes the lead screw to move linearly. The sixth aspect is, The pump mechanism in the fifth embodiment is such that the pipe nut is housed within the hollow tube, and the hollow tube is firmly attached to an external structure of the pump mechanism and supports the static plunger. The seventh aspect is, The pump mechanism in the first embodiment comprises one or more fluid ports, a first fluid port defined in the wall of the outer reservoir, and a second fluid port defined in the wall of the inner reservoir. The eighth aspect is, The first fluid port and the second fluid port are a pump mechanism in a seventh embodiment, which is fluidly connected to the outside of the pump mechanism. The ninth aspect is, The aforementioned drive mechanism, A push-in member defining a through hole having a female threaded portion, The push member comprises a lead screw that engages with the through hole, This is a pump mechanism in a first embodiment in which the rotation of the lead screw causes the pushing member to move linearly, such that the pushing member pushes the inner reservoir into the outer reservoir. The tenth aspect is, A pump mechanism in a ninth embodiment, wherein a fitting element is defined on the push-in member, and a corresponding fitting element is defined on the outer surface of the inner reservoir. The eleventh aspect is, The aforementioned drive mechanism is A rack gear positioned on the outer surface of the outer reservoir, The rack gear is engaged with a pinion gear, This is a pump mechanism in a first embodiment in which the rotation of the pinion gear causes the outer reservoir to move linearly toward the inner reservoir, thereby causing the inner reservoir to move linearly into the outer reservoir. The twelfth aspect is, The aforementioned drive mechanism is A second rack gear is positioned on the outer surface of the outer reservoir opposite to the aforementioned rack gear, The present invention further comprises a second pinion gear engaged with the second rack gear, This is a pump mechanism in an eleventh embodiment, in which the synchronous rotation of the pinion gear and the second pinion gear causes the outer reservoir to move linearly toward the inner reservoir, thereby causing the inner reservoir to move linearly into the outer reservoir. The 13th aspect is, The aforementioned drive mechanism, A push member which is integrated with or attached to the inner reservoir, and which defines a through hole having a female threaded portion, The push member comprises a lead screw that engages with the through hole, This is a pump mechanism in a first embodiment in which the rotation of the lead screw causes the linear movement of the pushing member and the linear movement of the inner reservoir into the outer reservoir. The 14th aspect is, The inner reservoir defines a second through-hole located on the outer surface of the inner reservoir on the opposite side of the through-hole, The aforementioned drive mechanism is A pump mechanism in a thirteenth embodiment further comprising a second lead screw that engages with a second through-hole of the inner reservoir, wherein the synchronized linear movement of the lead screw and the second lead screw causes the inner reservoir to move linearly into the outer reservoir. The 15th aspect is, The aforementioned drive mechanism is A second pressing member which is integrated with or attached to the inner reservoir, comprising a second pressing member which defines a through hole, A pump mechanism in a thirteenth embodiment further comprising a cylindrical rod disposed within the through hole of the second pushing member. The 16th aspect is, The pump mechanism in the first embodiment has a cross-sectional shape selected from the group consisting of an ellipse, a flattened circle, and a rectangle with rounded corners. The 17th aspect is, The pump mechanism in the first embodiment further comprises a fluid seal disposed on the circumferential surface of the static plunger so as to create a fluid seal between the static plunger and the inner surface of the inner reservoir. The 18th aspect is, The pump mechanism is a pump mechanism in a first embodiment, further comprising a fluid seal between the inner surface of the outer reservoir and the outer surface of the inner reservoir. The 19th aspect is, The pump mechanism is a pump mechanism in a first embodiment, further comprising a fluid seal between the hollow tube and the static plunger.

Claims

1. In a pump mechanism, The aforementioned pump mechanism is Outer reservoir and, An inner reservoir configured to move linearly within the outer reservoir, A static plunger is located inside the aforementioned inner reservoir, A hollow tube supporting the static plunger and extending between the inner reservoir and the outer reservoir, thereby fluidly connecting the inner reservoir to the outer reservoir, One or more fluid ports defined in either or both of the inner reservoir and the outer reservoir, The system includes a drive mechanism for linearly moving the inner reservoir into the outer reservoir, A pump mechanism in which one or more fluid ports include a first fluid port defined in the wall of the outer reservoir and a second fluid port defined in the wall of the inner reservoir.

2. The aforementioned pump mechanism is The pump mechanism according to claim 1, further comprising a fluid seal between the inner surface of the outer reservoir and the outer surface of the inner reservoir.

3. The pump mechanism according to claim 1, wherein the outer reservoir is firmly attached to an external structure of the pump mechanism.

4. The portion attached to the inner reservoir defines a through hole, The pump mechanism according to claim 1, wherein the drive mechanism comprises a lead screw that engages with the through hole such that the linear parallel movement of the lead screw causes the inner reservoir to move linearly into the outer reservoir.

5. The pump mechanism according to claim 4, wherein the drive mechanism further comprises a pipe nut that screws onto the lead screw such that the rotation of the pipe nut causes the lead screw to move linearly.

6. The pump mechanism according to claim 5, wherein the pipe nut is housed within the hollow tube, and the hollow tube is firmly attached to an external structure of the pump mechanism and supports the static plunger.

7. The pump mechanism according to claim 1, wherein the first fluid port and the second fluid port are fluidly connected to the outside of the pump mechanism.

8. The aforementioned drive mechanism, A push-in member defining a through hole having a female threaded portion, The push member comprises a lead screw that engages with the through hole, The pump mechanism according to claim 1, wherein the rotation of the lead screw causes the pushing member to move linearly, such that the pushing member pushes the inner reservoir into the outer reservoir.

9. The pump mechanism according to claim 8, wherein a fitting element is defined on the pressing member, and a corresponding fitting element is defined on the outer surface of the inner reservoir.

10. The aforementioned drive mechanism is A rack gear positioned on the outer surface of the outer reservoir, The rack gear is engaged with a pinion gear, The pump mechanism according to claim 1, wherein the rotation of the pinion gear causes the outer reservoir to move linearly toward the inner reservoir, thereby causing the inner reservoir to move linearly into the outer reservoir.

11. The aforementioned drive mechanism is A second rack gear is positioned on the outer surface of the outer reservoir opposite to the aforementioned rack gear, The present invention further comprises a second pinion gear engaged with the second rack gear, The pump mechanism according to claim 10, wherein the synchronous rotation of the pinion gear and the second pinion gear causes the outer reservoir to move linearly toward the inner reservoir, thereby causing the inner reservoir to move linearly into the outer reservoir.

12. The aforementioned drive mechanism, A push member which is integrated with or attached to the inner reservoir, and which defines a through hole having a female threaded portion, The push member comprises a lead screw that engages with the through hole, The pump mechanism according to claim 1, wherein the rotation of the lead screw causes linear movement of the pushing member and linear movement of the inner reservoir into the outer reservoir.

13. The inner reservoir defines a second through-hole located on the outer surface of the inner reservoir on the opposite side of the through-hole, The aforementioned drive mechanism is The pump mechanism according to claim 12, further comprising a second lead screw that engages with a second through-hole of the inner reservoir, wherein the synchronized linear movement of the lead screw and the second lead screw causes the inner reservoir to move linearly into the outer reservoir.

14. The aforementioned drive mechanism is A second pressing member which is integrated with or attached to the inner reservoir, comprising a second pressing member which defines a through hole, The pump mechanism according to claim 12, further comprising a cylindrical rod disposed within the through hole of the second pushing member.

15. The pump mechanism according to claim 1, wherein the inner reservoir and the outer reservoir have a cross-sectional shape selected from the group consisting of an ellipse, a flattened circle, and a rectangle with rounded corners.

16. The pump mechanism according to claim 1, further comprising a fluid seal disposed on the circumferential surface of the static plunger to generate a fluid seal between the static plunger and the inner surface of the inner reservoir.

17. The pump mechanism according to claim 1, further comprising a fluid seal between the inner surface of the outer reservoir and the outer surface of the inner reservoir.

18. The pump mechanism according to claim 1, further comprising a fluid seal between the hollow tube and the static plunger.

Images