Double-acting telescopic screw drive pump mechanism externally disposed in a storage section of a fluid delivery device

Abstract

The fluid delivery device has a syringe-barrel-shaped reservoir with a plunger and a plunger drive assembly including a double-acting, telescoping lead screw located on the rear and exterior side of the barrel. The sleeve screw and axial screw, which rotate simultaneously and in opposite directions, extend from the nested configuration of the plunger drive assembly and into the reservoir at a rate double their respective equal pitch and lead parameters when the sleeve screw is rotated. A threaded nut and gear fastener located on the end of the barrel receives the sleeve screw, and the threaded nut translates and rotates the sleeve screw in response to motor operation. The distal end of the axial screw can be secured to the plunger pusher to prevent rotation when the motor is imparting rotation to the threaded nut and sleeve screw.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 066,832, filed Aug. 18, 2020, the contents of which are hereby incorporated by reference in their entirety.

[0002] Exemplary embodiments generally relate to a pump mechanism for use in a fluid delivery device, such as a wearable drug infusion patch. Exemplary embodiments generally relate to a screw for controllably extending or retracting a plunger drive mechanism within a syringe barrel-shaped reservoir that does not affect the reservoir volume to ensure biocompatibility, is fully storable outside the reservoir, and is fixed within the reservoir for anti-rotation control.

Background Art

[0003] The design of a typical drug delivery patch-type pump has the challenge of achieving small size, low power consumption, accurate delivery, high reliability, and low manufacturing cost. Further, the design of the drug delivery patch-type pump should not affect the quality of the drug. For example, the materials used for the components of the pump mechanism that come into contact with the delivered fluid should not cause biocompatibility problems.

Summary of the Invention

[0004] The above-described problems and other problems are overcome by exemplary embodiments, and further advantages are realized.

[0005] Exemplary embodiments of the present disclosure realize several advantages, such as minimizing the envelope or form factor indicating the device size while retaining the beneficial features of a highly reliable and proven system, such as a more expensive non-portable pump system using a drug pen and pen needle, syringe, or lead screw drive mechanism.

[0006] Aspects of the exemplary embodiments provide a novel and improved structure of a double-acting telescopic screw drive pump mechanism that enables the use of a syringe barrel drug container or similar container that has been demonstrated to be drug-friendly or biocompatible for drugs and other fluids delivered via a fluid delivery device.

[0007] According to an exemplary embodiment, there is a reservoir comprising a distal end outlet port and a plunger movable along the longitudinal axis of the reservoir, wherein the plunger is configured to seal against the inner wall of the reservoir to prevent fluid introduced into a fluid chamber defined on a first side of the plunger and including the outlet port from leaking into a portion of the reservoir defined by a second side of the plunger; and a plunger drive assembly attached to the proximal end of the reservoir and including telescopic and simultaneously counter-rotating screws having similar pitch and lead parameters, the plunger drive assembly moving from a nested configuration in which it does not extend into the reservoir to an extended configuration in which it extends into the reservoir at a rate that is a multiple of the respective parameters of the pitch and lead of each screw when the threaded nut rotates. A fluid delivery device is provided that includes the above. According to aspects of the exemplary embodiments, an encoder(s) can be provided for the plunger drive assembly to generate feedback data related to the movement of the plunger drive assembly.

[0008] According to aspects of the exemplary embodiments, the screws include a sleeve screw and an axial screw, each having external threads that are helical in opposite directions. When the external threads of the sleeve screw are left-handed threads, the external threads of the axial screw are right-handed threads, and when the external threads of the sleeve screw are right-handed threads, the external threads of the axial screw are left-handed threads.

[0009] According to aspects of the exemplary embodiments, the internal and external threads of the sleeve screw have threads that are helical in opposite directions to each other.

[0010] According to an aspect of the exemplary embodiment, the threaded nut has an opening with an internal thread that cooperates with the external thread on the sleeve screw to advance the sleeve screw into the reservoir when the threaded nut is rotated.

[0011] According to an aspect of the exemplary embodiment, the reservoir further includes a gear retainer attached to its proximal end, the gear retainer receiving the distal end of the sleeve screw and having an opening sized to allow the sleeve screw and the axial screw to extend into the reservoir when the threaded nut rotates. Further, the gear retainer can have a through hole for ventilation.

[0012] According to an aspect of the exemplary embodiment, the plunger drive assembly further includes a plunger push member coupled to the distal end of the axial screw.

[0013] According to an aspect of the exemplary embodiment, when the plunger drive assembly is controlled to discharge a predetermined amount of fluid from the fluid chamber in the reservoir by displacing the plunger using a reverse screw, the plunger push portion removably abuts against the plunger and is configured to axially push the plunger towards the distal end of the reservoir.

[0014] According to an aspect of the exemplary embodiment, the axial screw is coupled to the plunger push portion and its rotation is restricted by a rotation prevention mechanism.

[0015] According to an aspect of the exemplary embodiment, the rotation prevention mechanism includes the reservoir and the plunger push portion having a non-circular cross-section that prevents the rotation of the plunger push portion in the reservoir when the sleeve screw rotates.

[0016] According to an aspect of the exemplary embodiment, the plunger drive assembly further includes an anti-rotation mechanism with a detent on the proximal side of the plunger pusher, dimensioned to cooperate with the distal end of the axial screw to prevent the plunger pusher from rotating relative to the inner wall of the reservoir when the sleeve screw rotates. For example, the distal end of the axial or innermost screw is dimensioned and / or shaped to be press-fitted into a detent of a corresponding dimension and / or shape. Further, the detent can include a through-hole extending to the distal side of the plunger pusher, and the distal end of the axial screw can extend through the through-hole, for example. The distal end of the axial screw can be thermally caulked to the distal side of the plunger pusher at the through-hole. The through-hole can include an anti-rotation slot to facilitate thermal caulking. Alternatively, the plunger pusher can include a protrusion on its distal side, and the through-hole can extend through the protrusion. According to another aspect, the plunger pusher can include at least one through-hole for ventilation and / or a depression along at least a part of its periphery for ventilation.

[0017] According to an aspect of the exemplary embodiment, the reservoir includes an inlet port connected to a filling device via an inlet fluid path to an inlet port provided in the fluid delivery device, and the plunger is configured to shift towards the proximal end of the reservoir when fluid is introduced from the inlet port into the fluid chamber, and the plunger drive assembly is configured to be nested during filling.

[0018] According to an aspect of the exemplary embodiment, the reservoir is a syringe barrel-shaped reservoir.

[0019] According to an aspect of the exemplary embodiment, the reservoir and the plunger have a cross-sectional shape selected from a non-circular shape and an elliptical cross-section.

[0020] According to an aspect of the exemplary embodiment, each screw has an equal pitch.

[0021] Additional aspects and / or other aspects and advantages of the exemplary embodiments will be set forth in the following description, will become apparent from the description, or may be learned by practice of the exemplary embodiments. Exemplary embodiments may include an apparatus having one or more of the above aspects and / or one or more of their features or combinations, and a method for operating such apparatus. Exemplary embodiments may include, for example, one or more features and / or combinations of the above aspects as recited in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or other aspects and advantages of the exemplary embodiments will be more readily understood from the following detailed description when taken in conjunction with the accompanying drawings.

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[0023] Throughout the drawings, like reference numerals are understood to refer to like elements, features, and structures.

DETAILED DESCRIPTION OF THE INVENTION

[0024] As will be understood by those skilled in the art, there are numerous ways to implement examples, improvements, and arrangements of the pump mechanism for a fluid delivery device according to the embodiments disclosed herein. While reference is made to the exemplary embodiments shown in the drawings and the following description, the embodiments disclosed herein are not intended to cover all alternative configurations and embodiments encompassed by the disclosed technical solutions, and those skilled in the art can readily understand that various modifications can be made and various combinations can be made without departing from the scope of the disclosed technical solutions.

[0025] Exemplary embodiments of the present disclosure achieve several advantages, such as minimizing the envelope or form factor indicating the device size while maintaining beneficial features of reliable and proven systems such as more expensive non-portable pump systems using drug pens and pen needles, syringes, or lead screw drive mechanisms. According to the exemplary embodiments described herein, a novel pump mechanism for a fluid delivery device is provided. The pump mechanism enables the use of a syringe barrel-type drug container or a similar container that has been proven to be suitable for or biocompatible with the drug and other fluids delivered via the fluid delivery device, and an nested telescopic screw configuration is adopted. The double-acting telescopic lead screw mechanism is located behind and outside the syringe barrel-type container. The exemplary embodiments described herein achieve a high-precision, controllable, compact, and efficient pump structure that minimally or does not affect the quality of the drug. According to the exemplary embodiments, telescopic, simultaneously counter-rotating sleeve screws and an axial screw that expand and contract from the nested configuration at a rate that is a multiple of the equal respective pitch / lead parameters are adopted. To achieve the counter-rotating function, the outer threads of the innermost screw and the sleeve screw (and the reservoir cap threads) must have opposite hand characteristics. When the outer threads of the sleeve screw (and the inner threads of the reservoir cap) are each right-handed or left-handed, the innermost or axial screw can be either left-handed or right-handed. Further, the inner threads of the sleeve screw always have opposite hand characteristics to the outer threads of the same screw. The power source rotates a gear train that rotates the sleeve screw via a nut. The axial screw, which is fixed to the plunger pusher and cannot rotate, advances as the threads of the sleeve screw rotate around the axial screw. Due to the telescopic action, for example, in contrast to a single forward lead screw used in existing patch-type pumps, the overall mounting area of the plunger drive mechanism is reduced. It should be noted that the overall screw drive torque is equal to the combined torque of the rotation of the innermost screw and the sleeve screw (added as in the overall effective lead).Also, unless the force from the drive mechanism, motor, and / or indicator has a selective rotational direction, whether the innermost screw rotates counterclockwise or clockwise is somewhat arbitrary.

[0026] FIG. 1 is a perspective view of a wearable fluid delivery device 10 configured according to an exemplary embodiment. The fluid (e.g., drug) delivery device 10 includes a base plate 12, a cover 14, and an insertion mechanism 16 in a non-deployed position. The reservoir fluid delivery device 10 can be filled with fluid (e.g., drug) by inserting the needle of a filled syringe 36 into a filling port (not shown) provided in the base plate 12 having an inlet fluid path from the filling port to the reservoir. It should be noted that the fluid delivery device 10 can be filled with fluid (e.g., drug) using different mechanisms and methods.

[0027] FIGS. 2A, 2B, 2C, and 2D are, respectively, a partial top view, a perspective view, a side view, and a top view showing the cover of the fluid delivery device of FIG. 1 removed, configured according to an exemplary embodiment. The base plate 12 supports an insertion mechanism 16, a motor 18, a power source such as a battery 20, a control board 50, and a reservoir 22 or container for storing the fluid delivered to the user via an outlet fluid path 24 from the outlet port of the reservoir to the insertion mechanism 16. The reservoir 22 can also have an inlet port connected to a filling port (e.g., provided in the base plate 12) via an inlet fluid path 26. Inside the reservoir 22, there is a plunger 28 having a stopper assembly. The proximal end of the reservoir 22 is also provided with a nut 70 that is rotated via a plunger drive assembly 30 having a telescopic and simultaneously counter-rotating sleeve screw 72 and shaft screw 74, a gear retainer 34, a motor 18, and a gear train 32 connected to a gearbox 44.

[0028] FIG. 3 is a block diagram of exemplary components of a fluid delivery device configured in accordance with an exemplary embodiment. The cover / housing, i.e., the housing of device 10, is denoted by 14. Device 10 has a skin holding subsystem 40, such as an adhesive pad, for connecting device 10 to the user's skin. The fluid delivery device 10 further includes a fluid movement module 42 that can include a reservoir 22, an insertion mechanism 16, and a motor 18, motor housing and gearbox 44, gear train 32, a pump mechanism (e.g., a plunger drive assembly 30), and an exit path 24. The fluid delivery device further includes an electrical module 50 including a power module (e.g., a battery 20) and a controller 52, a motor driver 54, an optional sensing module 56 for sensing a fluid flow state (e.g., an occlusion or a pump mechanism runaway), an optional audio driver 58 (e.g., during administration, indicating a decrease in reservoir volume, an occlusion, a successful combination with an external device, or other states by an audible alarm such as a buzzer), and an optional visual driver 60 providing visual feedback by a light emitting diode and / or an optional tactile driver providing tactile feedback by a vibration element, and an optional wireless driver 62 for wireless communication between the fluid delivery device and an optional remote pump control device (e.g., a smartphone or dedicated controller 63), and other electrical components. With respect to the sensing module 56, the fluid delivery device can include one or more encoders for providing feedback of a drive mechanism (e.g., a plunger drive assembly 30), for example, for purposes of determination and runaway prevention of the pump mechanism.

[0029] FIG. 4A, FIG. 4B, FIG. 4C, and FIG. 4D are top perspective views showing different stages of filling the reservoir of a fluid delivery device with the cover removed, constructed in accordance with an exemplary embodiment. The fluid filling chamber 64 within the reservoir 22 is defined distally or anteriorly of the plunger 28, which is configured to block fluid from entering a portion of the reservoir defined proximally or posteriorly of the plunger, such that when fluid is delivered from the reservoir, there is no contact between the fluid and the plunger drive assembly 30 or the gearing 34.

[0030] In FIG. 4A, the reservoir 22 is in an empty state without fluid, and the plunger 28 is in its most distal position. The plunger drive assembly 30 is shown to be fully retracted throughout FIGS. 4A - 4D. A user can insert the needle of a filled syringe 36 into a fill port (not shown) provided in the base plate 12 having an inlet fluid path 26 from the fill port to the reservoir 22, as shown in FIG. 2D. As fluid is transferred from the syringe 36 to the reservoir 22 via the inlet fluid path 26, the volume of the fluid chamber defined by the reservoir 22 by the front face of the plunger 28 increases, as shown in FIGS. 4B, 4C, and 4D, respectively. The plunger 28 has a stopper assembly to prevent leakage of fluid held in the fluid chamber portion 64 of the reservoir 22. The stopper assembly can include, for example, an elastic material similar to a syringe stopper.

[0031] Figures 5A and 5B are a rear perspective view and a front perspective view, respectively, of a gear fastener 34 configured according to an exemplary embodiment. The gear fastener 34 has a protrusion 80 for press-fitting or engaging with a pin or other component (not shown) provided on a reservoir attachment portion (e.g., a wall on a base plate, a mounting plate, an upper structure, or other structure in the device housing 14). The protrusion (e.g., tab) 80 can hold the gear fastener 34 in a predetermined position to react to the movement of the plunger and the force from the fluid pressure. However, in other alternative exemplary embodiments, it can be used to support the gear fastener 34 over a relatively large area to avoid local deformation. The gear fastener 34 has an opening 82 for receiving a first portion of the nut 70. The opening 82 has a thread 84 configured to cooperate with the external thread 72a of the sleeve screw 72. The number of threads 84 can be adjusted to balance torque and movement stability. The number of threads 84 can be added without adversely affecting the length (i.e., only a slight change in the drive nut shape is required). The recessed back surface 86 is configured to rotatably receive the distal end of the nut 70. The gear fastener 34 has a front surface 88 that can abut against the plunger push portion 76 when the plunger drive assembly 30 is fully retracted and the reservoir is filled (as shown, for example, in FIG. 4D). However, the gear fastener 34 does not necessarily have to abut against the plunger depending on the dimensions of the reservoir 22 and the plunger drive assembly 30. The gear fastener 34 also has at least one opening or through-hole 85 for ventilation. As described below, the push portion 76 also has an opening and / or gap that allows ventilation when moving axially within the reservoir 22.

[0032] Figures 6A and 6B are respectively a front perspective view and a rear perspective view of a plunger push part 76 configured according to an exemplary embodiment. The plunger push part 76 has a detent 90 on the rear surface to receive the key part 74b of the axial screw 74. Any protrusion 92 on the front surface of the plunger push part 76 can be pushed into the rear surface of the plunger 28. The push part 76, together with or instead of the cap 34 of the reservoir 22, is provided with a mechanism(s) for enabling ventilation. For example, the air discharge configuration can be in the form of a scalloped edge that is provided along at least a part of the perimeter of the push part 76 and includes a recess 76a. When the recesses 76a are provided around the push part 76, these mechanisms can be configured to bias the configuration and tolerances of some of the perimeters of these mechanisms 76a so that the edges of the remaining recesses are more raised, minimizing axial translation friction, and first contacting the surface of the internal reservoir cylinder to prevent rotation. The push part 76 can also be provided with one or more through holes 76b in the plate-like part of the push part for ventilation.

[0033] Figures 7A and 7B are, respectively, a side view of the plunger drive assembly 30 in the retracted position with respect to the gear retainer 34, and an exploded view of the components shown in Figure 7A, according to an exemplary embodiment. The plunger drive assembly 30 includes a nut 70 having teeth 70b on a part thereof that engage the gear train 32 and the motor 18. The distal portion of the nut 70 is rotatably received within the gear retainer 34. The internal threads 70c of the nut 70 engage the external threads 72a of the sleeve screw 72. The internal threads 72b within the cavity of the sleeve screw engage the external threads 74a of the innermost or axial screw 74. As will be described with respect to Figure 9, a key portion 74b is provided at the distal end of the axial screw 74 that engages a detent 90 of the plunger pusher 76. As shown in Figure 6A, the projection 92 can include an anti-rotation groove 92a. When assembled, the post at the distal end of the innermost screw 74 can extend through the pusher 76 and slightly beyond its projection 92 into the detent 90. The post at the distal end of the innermost screw 74 cooperates with the groove 92a during the heat staking of the innermost screw 74 to the pusher 76. The heat-staked end of the projection 92 is shown, for example, in Figure 7A. The nut 70 includes an encoder 70a for indexing and accurate dose delivery, providing feedback to the electrical module 50, and further preventing runaway or undesirable or inaccurate pump motor operation and rotation of the drive nut 70.

[0034] Figures 8A, 8B, 8C, 8D, and 8E are top perspective views of a fluid delivery device showing different stages of discharging fluid from a reservoir via a plunger drive assembly 30 configured according to an exemplary embodiment, with the cover removed. In Figure 8A, the plunger drive assembly 30 is in a fully retracted position, and the volume of the fluid filling chamber portion 64 of the reservoir 22 is maximized. The structure of the double-acting telescopic lead screw design of the plunger drive assembly 30 attached behind the reservoir 22 is beneficial for minimizing the overall installation area of the reservoir on the base plate 12 while maximizing the available fluid volume in the reservoir. The rear portion of the sleeve screw 72 extends beyond the nut 70 when the plunger drive assembly 30 is in a fully retracted position, but the overall length of the plunger drive assembly 30 in the non-deployed state, and thus the overall installation area of the reservoir 22 and the plunger drive assembly 30, is minimized by the double-acting telescopic lead screw design according to the exemplary embodiment.

[0035] In Figure 8B, the nut 70 is being rotated by the motor and gearbox 18 and the intermediate power transmission gear train 32 by the engagement of its teeth 70b. The internal thread 70b of the nut and the opening thread 84 of the gear retainer 34 cooperate with the external thread 72a of the sleeve screw 72 to advance the sleeve screw 72 through the nut 70 and the gear retainer 34 and into the reservoir 22. At the same time, the rotation of the sleeve screw 72 causes the non-rotating forward movement of the axial screw 74 fixed to the plunger pusher 76. As a result, the plunger 28 is advanced distally as the plunger pusher 76 advances distally to abut against the plunger 28. Figures 8C, 8D, and 8E show further double-acting extension at an essentially equal length of the sleeve screw 72 and the axial screw 74 as the nut is rotated by the motor and gearbox 18 and the intermediate power transmission gear train 32.

[0036] Referring to FIGS. 6B and 9, when the nut of the plunger drive assembly 30 is rotated by the motor and gearbox 18 and the intermediate power transmission gear train 32, the key portion 74b of the axial screw 74 and the corresponding detent 90 on the rear surface of the plunger push portion 76 serve as a rotation prevention mechanism for the plunger push portion 76 with respect to the reservoir 22. The axial screw 74 uses a key portion to engage with the plunger push portion 76. This key portion can engage with the non-circular plunger push portion shape, thereby preventing rotation by the shape, or the key portion can engage with an intermediate structure that acts to prevent rotation of the syringe barrel-shaped reservoir 22 during operation. This key portion 74b needs to be smaller than the external thread of the same innermost screw (e.g., the axial screw 74) so that it can be assembled from the rear end of the assembly. For example, the distal end of the axial screw 74 is such that the restricted rotation imparted to the axial screw 74 by other components 70 and 72 prevents the rotation of the plunger push portion 76 with respect to the inner wall of the reservoir 22, and the dimensions and / or shape can be determined to engage with the corresponding dimension and / or shape detent or recess 90 in the plunger push portion 76. This structure also relies on the elliptical syringe barrel-shaped reservoir 22, contains the drug, and can provide anti-rotation functionality. The elliptical shape also has the additional advantage of potentially reducing the height of the device.

[0037] The exemplary embodiments described herein employ an elliptical syringe barrel reservoir 22 to contain the agent or fluid to be delivered. The elliptical syringe barrel reservoir 22 provides an anti-rotation function and related advantages. For example, the anti-rotation provided by the essential structure of the elliptical syringe barrel reservoir 22 necessarily prevents the rotation of the barrel when torque acts. The elliptical shape also potentially has the further advantage of reducing the height of the device. However, separate components can also be used to achieve the same anti-rotation. For example, the axial screw 74 can be key-fixed to the stopper of the plunger push part 76 or other part 90. Therefore, even if the reservoir 22 is not elliptical (for example, has a round cross-section), anti-rotation of the plunger drive assembly 30 relative to the inner wall of the reservoir 22 during axial movement is still achieved.

[0038] The reservoir 22 can be configured to be durable, that is, not removable, but rather pre-provided within the housing 14 of the fluid delivery device. The reservoir 22 can be made of the same material as the syringe barrel and related stopper. The reservoir 22 can be pre-filled, and the plunger drive assembly 30 is initially in the retracted position. As an alternative, the housing 14 of the fluid delivery device can include a filling port and a fluid path 26 from the filling port to the reservoir 22. The filling port can be configured to be filled by the user using a syringe or a filling station fluidly coupled to the filling port.

[0039] The exemplary embodiments described herein use many technical principles, such as (a) the wedging force of the screw (e.g., the opposing threads of the sleeve screw 72 and the axial screw 74), (b) the drive unit, and the slide connection between the internally threaded nut 70 and the sleeve screw 72 (e.g., the internally threaded nut 70 and the sleeve screw 72 rotate together, but the screw 72 moves axially parallel to the outside of the nut 70), (c) the rotation prevention function of the axial screw 74 inside the cylindrical reservoir (e.g., either the plunger pressing part 76 or a separate structure), (d) the friction and gear power transmission related to the nut 70 and various screw members, (e) the aspect ratio for changing the syringe barrel-type drug container or reservoir 22 and the dosing accuracy according to the drug type and usage plan, and (f) the flat cell-type battery that reduces any space.

[0040] It should be understood that the exemplary embodiments described herein are subject to operational variations and alternative configurations. For example, different lead screw structures can be used to change the dosing accuracy. An encoder can be used to provide feedback of the drive mechanism 30. The plunger 28 can be repeatedly and fail - safe advanced using a stepper drive system. In general, a non - circular syringe barrel cross - section can be used to optimize space utilization and adjust the device size to an optimal size for user comfort. Depending on the type of drug and delivery rate, and the required accuracy, the syringe barrel - type reservoir 22 can be changed in aspect ratio. That is, a smaller ratio (wider cross - sectional area, shorter barrel) can be used to deliver the drug with lower accuracy, while a larger aspect ratio can be used to facilitate more accurate dosing. Also, the structure is based on a basic screw drive mechanism that is a function of the axial load (force or pressure) on which the push - up torque acts, the thread pitch, the friction parameters, and the diameter. In some cases, the equations can be further extended to incorporate details of the thread shape, such as the flank angle, lead angle, and many other specific parameters. ACME threads can generally be used to balance other functional parameters such as push - up torque, required power, efficiency, and smoothness of operation and cost.

[0041] Figures 10A and 10B are block diagrams of fluid delivery devices having a determination and runaway prevention function 96 and / or an encoder 98, respectively, according to an exemplary embodiment. The determination and runaway prevention device 96 is provided on the drive nut 70 to ensure controlled rotation of the nut 70 by the motor, thereby preventing runaway of the pump mechanism. As described above, rotation of the drive nut 70 causes axial parallel movement of the sleeve screw 72, which also causes axial parallel movement of the shaft screw 74 due to the telescoping of the screw and the configuration of simultaneous counter-rotation, as described herein. The shaft screw 74 provides axial movement to the push portion 76 of the plunger 28. The reservoir cap or gear retainer 34 provides longitudinal fixed support for the syringe barrel-shaped container or housing against friction by the sleeve screw. The gear retainer 34 can also provide ventilation, as well as fixed support and longitudinal rotational support for the syringe barrel-shaped container or housing against axial movement and torque of the push portion due to engagement of the innermost screw 74. The encoder (e.g., backup encoder) 98 is also connected to the drive nut 70 to provide feedback to the electrical module 50 and further protect against runaway of the drive nut 70 or unwanted or inaccurate operation and rotation of the pump motor (e.g., the electrical module can cut off the power to the motor if a runaway condition is sensed by the encoder 98).

[0042] The exemplary embodiments described herein and their equivalent variations provide technical solutions to many technical problems in existing fluid delivery devices, particularly patch-type or wearable fluid delivery devices. For example, there is no existing wearable, disposable patch pump with a nested, telescopic, and simultaneously counter-rotating screw technology as described herein. By utilizing the exemplary embodiments, it becomes possible to use a standard syringe barrel-type container as the reservoir 22, thus providing significant space savings for the mechanical drive mechanism located behind the moving plunger 28 on the complete outside of the syringe barrel, while simplifying drug compatibility. A large amount of reservoir can be used that exceeds the functions of existing commercially available devices.

[0043] Furthermore, the compact structure provided by the exemplary embodiments allows for further flexibility in the cross-sectional structure of the reservoir, thus enabling the designer of the fluid delivery device to, for example, slightly decrease the cross-sectional area (and extend the length), thereby providing additional design control that can benefit dosing accuracy by requiring more movement to dispense a minimal fluid dose. This increase in movement corresponds to a greater rotation of the rotary drive gear, which means that the drive motion can be more accurate.

[0044] A further technical solution provided by the exemplary embodiment is to use a syringe barrel-shaped container with an elliptical cross-section for the reservoir 22. A rotary screw (e.g., screw 72) that pushes the barrel, typically via the configuration of the nut 70 and the gear fastener 34, is usually made to rotate relative to the barrel 22. Thus, the shape feature is beneficial for preventing rotation. The elliptical syringe cross-section meets this requirement by not allowing rotation like a circular cross-section. It should be understood that the cross-sectional shapes of the reservoir and the plunger can be any non-circular shape. The ellipse is a cross-sectional shape that is geometrically easy to implement for promoting sealing and balancing forces, although other shapes may allow for better packaging. Depending on how the filling process is implemented, additional methods for preventing rotation can be implemented. For example, if variable filling is desired for the syringe 36 (e.g., operated by a patient), the plunger 28 can be attached to the bottom surface and pushed into the initial position by the amount of filling. By means of an anti-rotation configuration attached to the innermost screw (e.g., the axial screw 74), the screw set can have a pre-aligned engagement configuration to advance the plunger and properly engage it.

[0045] The configuration of the plunger drive assembly 30 components with respect to the reservoir 22 and the plunger 28 achieves several other advantages. For example, having a plunger drive assembly 30 attached to the proximal end of the reservoir 22 and having a nested configuration that does not extend into the reservoir chamber until the nut 70 rotates optimizes the use of the reservoir chamber for fluid delivery, as opposed to having to accommodate pre-delivery plunger drive components. Also, the overall length of the reservoir can be made substantially the same as the length of the housing, adding a small amount of upper space for providing the connection of the gear train 34 to the drive gear teeth 70b of the nut 70 and the nominal length of the sleeve screw 72 extending from the nut in the fully retracted position. Thus, the overall footprint of the pump mechanism is minimized, similar to the longitudinal axis dimension of the housing 14 of the fluid delivery device. Using the configuration of the plunger 28 and the plunger drive assembly 30 also minimizes the contact between the pump mechanism and the fluid being delivered and ensures biocompatibility between the fluid and the fluid delivery housing. The exemplary embodiments described herein use telescoping screws of appropriate size and thread configuration to achieve controlled movement of the syringe barrel type reservoir plunger 28. Screw threading technology is well defined and understood and allows for repeatable and powerful movement. When driven with a controlled movement at an appropriate resolution by the motor 18, the telescoping screws (e.g., 72 and 74) can provide accurate movement under virtually all environmental conditions. Further, the drive mechanism (e.g., the plunger drive assembly 30) does not affect the basic volume of the fluid chamber 64 in which the drug is present and thus does not affect any compatibility issues.

[0046] A variety of people, including but not limited to patients or healthcare providers, can operate or use the exemplary embodiments of the present disclosure. For simplicity, hereinafter, the operator or user will be referred to as the "user".

[0047] In the exemplary embodiments of the present disclosure, a variety of fluids can be used. For simplicity, hereinafter, the liquid in the injection device will be referred to as the "fluid".

[0048] It will be understood by those skilled in the art that the present disclosure is not limited in its application to the detailed structures and component configurations described in the above description or illustrated in the drawings. The embodiments described herein are capable of other embodiments and can be carried out or implemented in various ways. It should also be understood that the expressions and terms used herein are for the purpose of description and should not be regarded as limiting. The use of "including", "comprising", or "having" and their variants herein means including the items listed hereinafter, their equivalents, and additional items. Unless otherwise specifically limited, the terms "connected", "coupled", and "mounted" herein and their variants are used broadly and include direct and indirect connections, couplings, and mountings. Further, the terms "connected" and "coupled" and their variants are not limited to physical or mechanical connections or couplings. Further, terms such as up, down, bottom surface, and top surface are relative and are used for the purpose of assisting the description and are not limiting.

[0049] The components of the example apparatus, system, and method employed in accordance with the illustrated embodiments can be implemented, at least in part, in digital electronic circuitry, analog electronic circuitry, or the hardware, firmware, software, or combinations thereof of a computer. These components can be implemented as a computer program product, such as a computer program, program code, or computer instructions embodied tangibly in an information medium or machine-readable storage device for execution by, or to control the operation of, a data processing apparatus, such as a programmable processor, a computer, or multiple computers.

[0050] The above description and figures are intended only by way of example and are not intended to limit the invention in any way except as set forth in the following claims.

Claims

1. A fluid delivery device comprising: a reservoir having a distal end outlet port and a plunger movable along the longitudinal axis of the reservoir, the plunger being configured to seal against the inner wall of the reservoir to prevent fluid introduced into a fluid chamber including the outlet port defined on a first side of the plunger from leaking into a portion of the reservoir defined by a second side of the plunger; a plunger drive assembly attached to the proximal end of the reservoir and including telescoping and simultaneously counter-rotating screws having similar pitch and lead parameters, the plunger drive assembly moving from a nested configuration in which it does not extend into the reservoir to an extended configuration in which it extends into the reservoir at a rate that is a multiple of the respective parameters of the pitch and lead of each screw when the threaded nut rotates; comprising: the screws comprising a sleeve screw and an axial screw, each having external threads that are helical in opposite directions, the external threads of the axial screw being right-handed when the external threads of the sleeve screw are left-handed and the external threads of the axial screw being left-handed when the external threads of the sleeve screw are right-handed; the reservoir further comprising a gear fixture attached to its proximal end, the gear fixture receiving the distal end of the sleeve screw and having an opening dimensioned to allow the sleeve screw and the axial screw to extend into the reservoir when the threaded nut rotates.

2. A fluid delivery device comprising: a reservoir having a distal end outlet port and a plunger movable along the longitudinal axis of the reservoir, the plunger being configured to seal against the inner wall of the reservoir to prevent fluid introduced into a fluid chamber including the outlet port defined on a first side of the plunger from leaking into a portion of the reservoir defined by a second side of the plunger; A plunger drive assembly attached to the proximal end of the storage portion, including telescopic and simultaneously mutually reverse rotating screws having similar pitch and lead parameters, such that when the threaded nut rotates, it moves from a nested configuration that does not extend into the storage portion to an extended configuration that extends into the storage portion at a rate that is a multiple of the respective parameters of the pitch and lead of each screw. Comprising: The screws each comprise a sleeve screw and an axial screw, each having external threads that rotate in opposite directions. When the external threads of the sleeve screw are left-handed threads, the external threads of the axial screw are right-handed threads, and when the external threads of the sleeve screw are right-handed threads, the external threads of the axial screw are left-handed threads. The plunger drive assembly further comprises a plunger pressing portion coupled to the distal end of the axial screw. When the plunger drive assembly is controlled to discharge a predetermined amount of fluid from the fluid chamber in the storage portion by displacing the plunger using the mutually reverse rotating screws, the plunger pressing portion is removably abutted against the plunger and is configured to axially push the plunger toward the distal end of the storage portion. The axial screw is a fluid delivery device coupled to the plunger pressing portion and rotationally restricted by a rotation prevention mechanism. **Claim 3** The fluid delivery device according to claim 1 or claim 2, wherein the internal threads of the sleeve screw and the external threads of the sleeve screw have threads that rotate in opposite directions to each other. **Claim 4** The fluid delivery device according to claim 1 or claim 2, wherein the threaded nut has an opening with internal threads that cooperate with the external threads of the sleeve screw to advance the sleeve screw into the storage portion when the threaded nut rotates. **Claim 5** The fluid delivery device according to claim 1, wherein the gear fastener comprises a through hole for ventilation. **Claim 6** The fluid delivery device according to claim 2, wherein the rotation prevention mechanism comprises the storage portion and the plunger pressing portion having a non-circular cross-section that prevents rotation of the plunger pressing portion in the storage portion when the sleeve screw rotates. **Claim 7** The plunger drive assembly further comprises an anti-rotation mechanism with a backstop on the proximal side of the plunger pushing portion, dimensioned to cooperate with the distal end of the axial screw to prevent the plunger pushing portion from rotating relative to the inner wall of the reservoir when the sleeve screw rotates, for the fluid delivery device according to claim 2.

8. The distal end of the axial screw is dimensioned and / or shaped to be press-fitted into a backstop of a corresponding dimension and / or shape, for the fluid delivery device according to claim 7.

9. The backstop includes a through-hole extending to the distal side of the plunger pushing portion, and the distal end of the axial screw extends through the through-hole, for the fluid delivery device according to claim 7.

10. The distal end of the axial screw is thermally caulked on the distal side of the plunger pushing portion in the through-hole, for the fluid delivery device according to claim 9.

11. The through-hole includes an anti-rotation slot for facilitating thermal caulking, for the fluid delivery device according to claim 10.

12. The plunger pushing portion includes a protrusion on its distal side, and the through-hole extends through the protrusion, for the fluid delivery device according to claim 9.

13. The plunger pushing portion includes at least one through-hole for ventilation, for the fluid delivery device according to claim 2.

14. The plunger pushing portion includes a depression along at least a part of its periphery for ventilation, for the fluid delivery device according to claim 2.

15. The reservoir includes an inlet port connected via an inlet fluid path to a filling port provided in the fluid delivery device and coupled to a filling device, the plunger is configured to shift towards the proximal end of the reservoir when fluid is introduced from the inlet port into the fluid chamber, and the plunger drive assembly is configured to be nested during filling, for the fluid delivery device according to claim 1 or claim 2.

16. The reservoir is a syringe barrel-shaped reservoir, for the fluid delivery device according to claim 1 or claim 2.

17. The reservoir and the plunger have a cross-sectional shape selected from a non-circular shape and an elliptical cross-section, for the fluid delivery device according to claim 1 or claim 2.

18. Each of the screws has an equal pitch, for the fluid delivery device according to claim 1 or claim 2.

19. The fluid delivery device according to claim 1 or claim 2, further comprising an encoder for the plunger drive assembly, and generating feedback data related to the movement of the plunger drive assembly.

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