Compact Fluid Delivery System

Abstract

The fluid delivery system includes a propulsion unit disposed opposite the plunger within the barrel of the cartridge and configured to expel fluid from the cartridge. The propulsion unit has a motor shaft disposed coaxially with the cartridge. A motor shaft gear is attached to the motor shaft, and multiple wheel extensions are disposed around the motor shaft, each wheel extension having a secondary gear, one or more wheels, and a wheel gear attached to the one or more wheels. Rotation of the motor shaft in a first direction deploys the multiple wheel extensions until the wheels of the multiple wheel extensions contact an inner wall of the cartridge, and then rotation of the motor shaft causes the wheels to rotate along the inner wall, propelling the propulsion unit and advancing the plunger.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates generally to the field of devices for fluid delivery, and in particular to devices for drug delivery via wearable systems. [Background technology]

[0002] Wearable fluid delivery devices are becoming increasingly popular because they offer convenience to patients who require regular injections of medications and / or supplements. Such devices can be worn on the patient's body to release fluids (or injectables) over a period of time. Delivery can be intravenous (IV), intramuscular (IM), or subcutaneous (SQ). Similar configured fluid delivery devices also have additional uses, such as wet lab research, industrial applications, and other applications requiring precise, small-scale fluid delivery.

[0003] The fluid delivery device is described in International Patent Publication WO 2021 / 099992 A2 to Ben David, the inventor of the present invention. The fluid delivery device includes a mechanism having a central longitudinal axis and arranged for axial advancement. The mechanism includes a housing and one or more swing members pivotally coupled to the housing and arranged to swing relative to the housing between an initial position and an end position.

[0004] A more compact fluid delivery device has the potential to improve convenience and ease of use in a variety of applications. Summary of the Invention [Problem to be solved by the invention]

[0005]

[0006] Embodiments of the present invention provide systems and methods for fluid delivery, particularly for delivery of medications such as insulin or nutritional supplements to a patient, such as by injection from a wearable device. The system may include a propulsion unit for driving a plunger within a barrel of a cartridge to expel fluid from the cartridge. The propulsion unit may include a bidirectional motor having a motor shaft rotatable in first and second directions, and the propulsion unit may be configured to be disposed within the cartridge barrel with the motor shaft coaxially aligned with the cartridge. The propulsion unit may also include a motor shaft gear attached to the motor shaft and multiple wheel extensions disposed around the motor shaft, such that rotation of the motor shaft in the first direction deploys the wheel extensions until wheels of the multiple wheel extensions contact an inner wall of the cartridge, and when the wheels contact the inner wall of the cartridge, rotation of the motor shaft in the first direction rotates the wheels to propel the propulsion unit and advance the plunger. Each wheel extension may consist of a secondary gear, one or more wheels, and wheel gears attached to the axles of one or more wheels. The secondary gear of each wheel extension may be in mesh with the motor shaft gear and the wheel gear. [Brief explanation of the drawings]

[0006] For a better understanding of various embodiments of the present invention and to show how the same may be put into practice, reference will now be made, by way of example, to the accompanying drawings, in which structural details of the invention are shown to provide a basic understanding of the invention, and the description, taken in conjunction with the drawings, will make apparent to those skilled in the art how several forms of the invention may be embodied in practice.

[0007] In the attached drawing

[0008] [Figure 1] 1 is a schematic diagram of a system for fluid delivery, according to some embodiments of the present invention. [Figure 2A-2B]1 is a schematic diagram of a system for fluid delivery, according to some embodiments of the present invention.

[0009] [Figure 3] FIG. 1 is a schematic diagram of a drive section of a system according to some embodiments of the present invention.

[0010] [Figure 4] 1 is a schematic diagram of a fluid cartridge of a system according to some embodiments of the present invention.

[0011] [Figure 5] 1 is a schematic diagram of a delivery portion of a system, according to some embodiments of the present invention.

[0012] [Figures 6A-6B] 1 illustrates peripheral devices of a system according to some embodiments of the present invention. [Figure 7] 1 illustrates peripheral devices of a system according to some embodiments of the present invention.

[0013] [Figure 8] FIG. 1 is a schematic diagram of a propulsion unit of a system including a helical shaft assembly, according to some embodiments of the present invention. [Figure 9] FIG. 1 is a schematic diagram of a propulsion unit of a system including a helical shaft assembly, according to some embodiments of the present invention. [Figure 10] FIG. 1 is a schematic diagram of a propulsion unit of a system including a helical shaft assembly, according to some embodiments of the present invention. [Figures 11A-11B] FIG. 1 is a schematic diagram of a propulsion unit of a system including a helical shaft assembly, according to some embodiments of the present invention. [Figure 12] FIG. 1 is a schematic diagram of a propulsion unit of a system including a helical shaft assembly, according to some embodiments of the present invention.

[0014] [Figure 13]1 is a schematic diagram of a propulsion unit with an alternative shaft assembly, according to some embodiments of the present invention. [Figure 14] 1 is a schematic diagram of a propulsion unit with an alternative shaft assembly, according to some embodiments of the present invention. [Figure 15] 1 is a schematic diagram of a propulsion unit with an alternative shaft assembly, according to some embodiments of the present invention. [Figure 16] 1 is a schematic diagram of a propulsion unit with an alternative shaft assembly, according to some embodiments of the present invention. [Figure 17] 1 is a schematic diagram of a propulsion unit with an alternative shaft assembly, according to some embodiments of the present invention. [Figure 18] 1 is a schematic diagram of a propulsion unit with an alternative shaft assembly, according to some embodiments of the present invention. [Figure 19] 1 is a schematic diagram of a propulsion unit with an alternative shaft assembly, according to some embodiments of the present invention.

[0015] [Figure 20] 1 is a schematic diagram of a base element of a system including a retraction band, according to some embodiments of the present invention. [Figure 21] 1 is a schematic diagram of a base element of a system including a retraction band, according to some embodiments of the present invention. [Figure 22] 1 is a schematic diagram of a base element of a system including a retraction band, according to some embodiments of the present invention.

[0016] [Figure 23] 1 is a schematic diagram of a coupling mechanism of a system according to some embodiments of the present invention. [Figure 24] 1 is a schematic diagram of a coupling mechanism of a system according to some embodiments of the present invention. [Figure 25] 1 is a schematic diagram of a coupling mechanism of a system according to some embodiments of the present invention. [Figures 26A-26B]1 is a schematic diagram of a coupling mechanism of a system according to some embodiments of the present invention.

[0017] [Figures 27A-27B] 1 is a schematic diagram of an adhesive mechanism of a system according to some embodiments of the present invention. [Figures 28A-28B] 1 is a schematic diagram of an adhesive mechanism of a system according to some embodiments of the present invention. [Figures 29A-29B] 1 is a schematic diagram of an adhesive mechanism of a system according to some embodiments of the present invention.

[0018] [Figure 30] 10A-10C are schematic diagrams of mechanisms illustrating priming of hypodermic needles of the system, according to some embodiments of the present invention.

[0019] [Figures 31A-31C] FIG. 1 is a schematic diagram of a mechanism for priming the system and sensing skin contact, according to some embodiments of the present invention.

[0020] [Figures 32A-32E] 1A-1C are schematic diagrams illustrating drive plate configurations according to some embodiments of the present invention.

[0021] [Figure 33A-33B] 10A-10C are schematic diagrams of mechanisms for sealing the drive and delivery units, according to some embodiments of the present invention. [Figure 34A-34B] 10A-10C are schematic diagrams of mechanisms for sealing the drive and delivery units, according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] It is to be understood that the invention and its applications are not limited to the systems and methods described below or to the arrangements of components described or illustrated in the drawings, but are applicable to embodiments that can be practiced or carried out in various ways.

[0023] 1 is a schematic diagram of a system 100 for fluid delivery, according to some embodiments of the present invention. System 100 includes three main parts or components: a drive unit 110, a cartridge 120, and a delivery unit 130. In typical use, cartridge 120 is mated with drive unit 110 (also referred to herein as the "reusable part") and then attached to delivery unit 130 (also referred to herein as the "disposable part"). Fluid within fluid cartridge 120 is expelled through delivery unit 130, after which the cartridge is refilled or replaced by separating the drive unit and delivery unit.

[0024] 2A and 2B are schematic diagrams of the top 210 and bottom 220 of system 100, respectively, when the system is assembled, i.e., with the drive and delivery sections joined. A typical application for system 100 is as a wearable device for automatic drug injection, such as an insulin pump. Top 210 can include a needle trigger port 212 to which a hypodermic needle (and / or cannula) 230 (referred to herein as needle / cannula 230) can be added, which is shown passing through an injection opening 232 on bottom 220 of the system. For insulin pump applications, system 100 can be attached to a patient's skin, and the patient can wear the system to administer multiple injections over time. For such applications, delivery section 130, as well as cartridge 120, are typically discarded after each use to ensure sterility. Bottom section 220 includes an adhesive for adhering to the patient's skin, as described further below. Typically, both the adhesive side and the needle trigger port 212 are elements of the delivery portion 130 of the system.

[0025] It should be understood that in some alternative applications, such as applications providing fluid delivery without injection, delivery portion 130 may be reusable, i.e., not necessarily intended to be disposed of after a single use. For such alternative applications, the cartridge may alternatively be refillable. Examples of such applications include electronic cigarettes and adhesive applicators. In the following, delivery portion 130 will also be referred to as the disposable portion, and drive portion 110 will also be referred to as the reusable portion, in consideration of non-limiting medical applications that require disposal of the delivery portion (i.e., "single-use" applications).

[0026] FIG. 3 is a schematic diagram of the drive unit 110 having a cover 300. The cover 300 is shown semi-transparently to allow visibility of the internal components. These components may include a propulsion unit 302 having a motor 304 and wheels 306. Hereinafter, the propulsion unit is also referred to as a "propulsion device." Furthermore, the drive unit typically has a base 308 on which components are attached, including a flex cable 310, i.e., a strip such as a flat flex cable (FFC) or flexible printed circuit (FPC). The flex cable 310 is also referred to herein as a retraction band, since one of its functions may be to retract the propulsion unit. The base 308 may also include a printed circuit board (PCB) 312 and an encoder 314. The PCB 312 typically includes a controller (not shown) or similar processor, including a memory for storing instructions, as described further herein. The PCB 312 may also include a communication device or driver for external communication, for example with an external controller such as a mobile device, configured to send instructions to the controller and provide status notifications to a user related to the operation of the system.

[0027] The drive cover 300 includes a cartridge port 320 into which the plunger end of the cartridge 120 is placed (described further herein). Additional drive components include a power source, i.e., a battery 322, battery charger contacts 324, and a buzzer and / or display 340, which may be used to communicate messages to the user, such as an error or an empty cartridge notification (if the battery is intended to be disposable after a single use, it may also be located in the disposable delivery portion of the system, or in any portion for non-single use applications).

[0028] 4 is a schematic diagram of the fluid cartridge 120 of the fluid delivery system 100. The cartridge includes a cartridge plunger 400, which is a flexible plug disposed within the cartridge barrel 410 and fits against the interior wall 412 of the cartridge.

[0029] As the plunger 400 is pushed forward, it travels forward within the barrel 410 along the central axis of the cartridge, causing the fluid 420 to be expelled from the cartridge through the cartridge delivery end 430. As shown, the cartridge fluid delivery end 430 is at the end of the cartridge opposite the plunger end 440. A syringe in the delivery portion of the system may be configured to pierce a seal 432 at the delivery end 430 to access the fluid.

[0030] FIG. 5 is a schematic diagram of the delivery portion 130 of the fluid delivery system 100. As described above, the two elements of the delivery portion may be the needle trigger port 212 and the adhesive bottom surface 220. An additional component that may be provided with the delivery portion is a cartridge delivery end port 510 that receives the cartridge delivery end 430. Upon insertion of the cartridge into the port 510, the seal at the delivery end of the cartridge is typically pierced by a syringe 520 connected to tubing 522 of the delivery portion. The cartridge needle and connected tubing may be connected to the needle and / or cannula 230 by a needle injector, as described below with respect to FIGS. 6-7. The delivery portion 130 may also include an interlocking connector 540, which is described in more detail herein.

[0031] 6A and 6B show peripheral devices of the system 100 for fluid delivery. Fig. 6A shows a charger 610 for recharging the system's battery. The system 100 is inserted into the charger 610 so that the cartridge charger contacts 324 described above contact the charger contacts. Alternatively, or additionally, the system 100 can include an inductive charging coil so that it can be charged by inductive charging.

[0032] As described above, the system may communicate with an external device, such as a mobile device with a suitably configured app that transmits instructions, such as dosage, to the system. The mobile device app can also provide error messages to the user, notifying them of, for example, a low battery condition or an event that requires the system to be recharged (or the battery replaced). The mobile device app can also interact with the system to send instructions to advance the propulsion unit to prime the needle before application to the user's skin. For example, before the user applies the system to their skin, the mobile device app can request the user's approval to expel an additional drop from the needle. Upon receiving user approval (e.g., by the user clicking "OK" on the app screen), the mobile device can send instructions to the system to advance the propulsion unit a small amount (e.g., 0.5 mm) to expel an additional drop from the needle. The user can then be asked to confirm the successful expulsion of the drop, i.e., the successful priming of the needle. After confirming priming, the user receives a notification that the system has been applied to the skin.

[0033] FIG. 6B shows a needle injector 620 including a needle injector cover 622 that can be provided to fit over a delivery portion for injecting a needle for intramuscular or subcutaneous fluid delivery.

[0034] FIG. 7 is a schematic diagram of needle injector 620, showing a spring mechanism 700 by which needle / cannula 230 may be injected, as described above.

[0035] FIG. 8 is a schematic diagram of the propulsion unit 302 of the fluid delivery system 100. The propulsion unit's bidirectional motor 304 drives the propulsion unit's wheels 306, propelling the propulsion unit through the barrel 440 of the cartridge 120. The motor 304 has a shaft 800 to which a shaft assembly 802 is attached. The motor is configured to fit within the cartridge, with the motor shaft coaxially aligned with the cartridge (as described above with respect to FIGS. 3-4). The wheels 306 are attached to the shaft assembly 802, which further includes several gears mounted around the motor. The shaft assembly 802 shown in FIG. 8 is configured for helical propulsion of the propulsion unit and is therefore also referred to herein as a helical configuration of the shaft assembly, or more simply, a "helical" shaft assembly 802. Helical shaft assemblies are depicted in FIGS. 8-12. In a helical configuration, the wheels 306 are mounted on an axis inclined at an angle greater than 0 and less than 90 degrees relative to the motor shaft, as shown in Figure 9. An alternative configuration of the shaft assembly, referred to herein as a direct shaft assembly 1300, is described below with reference to Figures 13-19.

[0036] Both the helical and direct configurations of the shaft assembly include a drive plate 810. When the propulsion unit is initially placed into the cartridge barrel, i.e., when the driver and delivery sections are coupled, the drive plate 810 can be configured to contact the cartridge plunger and push the cartridge plunger slightly forward. The initial push of the plunger overcomes any static friction previously built up between the plunger and the cartridge wall (i.e., after the manufacture of the filled cartridge). Thereafter, static friction is lower, thereby reducing the force the propulsion unit must apply to drive the plunger by self-propulsion. The initial push applied to the plunger by coupling the driver and delivery section can be configured to expel a small amount of fluid from the cartridge and prime the ejection needle (described further herein). In Figures 9-11, the drive plate of the shaft assembly has been removed, revealing additional components of the shaft assembly.

[0037] FIG. 10 is a perspective view of a propulsion unit 302 with a helical shaft assembly 802. As described above, the propulsion unit includes a motor 304 having a motor shaft 800. A shaft assembly 802 (such as the alternative shaft assembly 1300 described below) is disposed about the motor shaft 800. A motor gear 1002 of the shaft assembly 802 is fixed to and rotates with the motor shaft 800. The motor gear 1002 meshes with a secondary gear 1006 of each wheel extension 1004. As shown, the shaft assembly includes multiple wheel extensions 1004, which are generally disposed about the motor shaft in a symmetrical manner, i.e., with similar spacing (e.g., within a ±10% range) between each wheel extension.

[0038] Each secondary gear 1006 rotates about a secondary gear axis 1008. The secondary gear axis 1008 is tilted from an axis parallel to the motor shaft (i.e., tilted from an axis in the plane of the motor shaft, as shown in FIG. 9). Typically, the gripper gear 10 is also mounted on the secondary gear axis 1008 or otherwise configured to rotate with the secondary gear and is meshed with a stationary gear 1012. The stationary gear 1012 is located at the proximal end of the motor shaft and is attached to the motor such that the motor shaft passes through the stationary gear.

[0039] The traction of the gripper gear 1010 on the fixed gear constrains the rotation of the gear motor 304 relative to the direction of rotation of the wheel extension, i.e. the motor does not rotate relative to the cartridge.

[0040] Each wheel extension 1004 includes at least one, typically two, wheels 306 (more wheels may provide greater traction). Each wheel or wheel pair has a common wheel gear 1020. As shown, each wheel gear 1020 meshes with its common wheel extension's respective secondary gear 1006, which in turn meshes with the motor gear 1002. The gears 1002, 1006, 1012, and 1020 (i.e., motor gear, secondary gear, fixed gear, and wheel gear) may be different sizes so that different rotation ratios can be achieved, meaning that the wheels do not necessarily rotate at the same speed as the motor shaft. Typically, the motor gear is smallest, and the wheels rotate more slowly than the motor gear. While all gears in the helical shaft assembly are shown as spur gears, they may have helically tapered grooves to facilitate the wheel tilting described above. It should be understood that the illustrated gear configuration is exemplary and that the gear arrangement may include additional or alternative types of gears (e.g., helical gears) for transmitting torque from the motor shaft to the wheel gears.

[0041] Also shown in Figure 10 is a wheel extension plate 1040. Such a plate may include elements that may be included in a spiral wheel extension 802 in the same manner as those included in a direct wheel extension 1300, as shown in Figure 16, described below. These elements may include a connecting plate 1630 that connects the wheel axle to the secondary gear axle. Additional elements of the extension plate 1040 may include a ratchet gear 1640 and pawl spring 1642, as well as a torsion spring (1520), or similar device, which are described further herein.

[0042] 11A and 11B are top views of the propulsion unit 302, showing the gear of the helical shaft assembly 802 above the motor 304. The wheel extensions are shown in their deployed state (contacting the cartridge wall) in FIG. 11A and their folded state (in and out of the cartridge position) in FIG. 11B. Also shown is the wheel axle 1100 of the helical shaft assembly. As mentioned above, the wheel axle is tilted from an axial direction parallel to the motor shaft, so that as the wheels rotate, the shaft assembly advances into the cartridge barrel in a helical pattern, as shown below with respect to FIG. 12. When the wheels are deployed to contact the inner cartridge wall, as shown in FIG. 11A, they are typically still slightly bent at an angle θ1 relative to a line extending directly from the motor shaft to the secondary gear. In this position, the maximum radius of the shaft assembly, including the wheel extensions, is shown as R1. In FIG. 11B, the wheel extensions are folded, releasing their grip from the inner cartridge wall. The wheel extensions are folded at an angle θ 2, The sphere is shown folded only by a radius R2, which is smaller than R1.

[0043] FIG. 12 is a perspective view of cartridge 120 illustrating the spiral motion of helical shaft assembly 802 as propulsion unit 302 advances within the cartridge.

[0044] 13 is a perspective view of the alternative shaft assembly described above, referred to herein as a direct shaft assembly 1300. The wheels 306 and their wheel gears 1200 of the direct shaft assembly are mounted on an axis perpendicular to the motor shaft, in contrast to the tilted wheel axes of the helical shaft assembly 802. The gears of the direct shaft assembly 1300 are held in place by a direct shaft assembly frame 1310, which also holds the drive plate 810 in place (as was the case with the helical shaft assembly 802).

[0045] FIG. 14 is a diagram of a direct shaft assembly 1300 with the shaft assembly frame 1310 shown transparent to show the gear structure of the direct shaft assembly, including the direct motor shaft gear 1400. In contrast to the motor gear 1002 of the helical shaft assembly 802, the direct motor shaft gear 1400 is configured to mesh with the secondary gear at a 90-degree angle. The direct motor shaft gear 1400 is typically a worm gear, as shown, or another type of gear that transmits 90-degree rotation, such as a bevel gear. As a result, the wheel axles 1410 of the direct shaft assembly 1300 are perpendicular to the motor shaft. (Each wheel axle 1410 is also parallel to a plane tangent to the wheel-cartridge contact point.)

[0046] FIG. 15 is a further perspective view of the direct shaft assembly 1300, showing additional elements. Like the helical shaft assembly 802, the direct shaft assembly 1300 is disposed around the propulsion unit's motor shaft 800. Like the helical shaft assembly 802, the direct shaft assembly 1300 also has multiple wheel extensions, shown as wheel extensions 1510. Typically, each wheel extension has a torsion spring 1520 that applies pressure to "open" the wheel extension into a configuration in which the wheels are away from the motor shaft. The torsion springs are secured to the shaft assembly frame 1310 by a torsion spring brace 1522. Also shown are a shaft assembly lower bearing 1530 and a shaft assembly upper bearing 1532. It should be noted that, like the direct shaft assembly 1300, the helical shaft assembly 802 described above similarly has its own torsion spring 1520 that applies pressure to "open" each wheel extension into a configuration in which the wheels contact the inner wall of the cartridge. In the open ("deployed") position, the torsion spring maintains pressure on the wheel extension to ensure the level of friction necessary for the wheel to grip the cartridge wall, thereby propelling the propulsion unit forward as the wheel rotates.

[0047] FIG. 16 is a further perspective view of the direct shaft assembly 1300, showing additional elements of the wheel extension 1510. These elements include a secondary gear 1006 that meshes with both the direct motor shaft gear 1400 and the wheel gear 1020, such that rotation of the motor shaft gear 1400 rotates the secondary gear 1620, which in turn rotates the wheel gear 1020. The secondary gear 1620 may be identical to the secondary gear 1006 of the helical shaft assembly described above (also, multiple secondary gears may be included on the secondary axle 1630, for example, if different gear ratios are desired). Furthermore, it should be understood that the wheel extension 1004 of the helical shaft assembly, like the wheel extension 1510, typically includes a ratchet gear 1640 secured to the axle of the wheel and wheel gear, and a pawl spring 1642 secured to the axle of the secondary gear. A connecting plate 1644 also typically connects the two axles. In typical operation, regardless of the type of shaft assembly, the propulsion unit is inserted into the cartridge by its plunger end when the wheel extension is "closed" so that the wheels do not contact the inner wall of the cartridge. The motor then rotates the motor gear, which rotates the secondary gear. Due to the torsion spring, the rotation of the secondary gear first lifts the wheel extension, widening it until the wheels contact the inner wall of the cartridge. Because the wheels do not begin to rotate until they contact the inner wall of the cartridge, the torsion spring cannot open the wheel extension any further (although it continues to apply pressure as described above).

[0048] When the propulsion unit retracts from the cartridge, the reverse rotation of the motor gear causes a similar reverse rotation of the secondary gear. However, as the secondary gear rotates, the ratchet gear engages the pawl spring, preventing the wheel gear from rotating. Instead, the wheel extension folds, separating the wheel from the cartridge wall.

[0049] Figure 17 shows that an initial rotation R1 of the motor shaft causes a rotation S1 of the secondary gear. Due to the torsion spring, the secondary gear first lifts the wheel indicated by the arrow E1. The wheel starts to rotate (in the direction W1) after it reaches the open position where the wheel extension contacts the inner wall of the cartridge. The rotation of the wheel (W1) propels the propulsion unit into the cartridge in the direction X1.

[0050] When the motor shaft rotates in the reverse direction (shown as R2 in FIG. 18), the secondary gear rotates in the reverse direction S2. This initially causes the wheel (W2) to rotate slightly until the ratchet and pawl lock. Further rotation of the wheel is then impossible, and further rotation of the secondary gear closes the wheel extension, separating the wheel from the inner wall of the cartridge. The elements of the wheel extension are more clearly detailed in the side view of FIG. 19, showing the ratchet and pawl contact 1900, preventing reverse wheel rotation. While FIGS. 17-19 show an example of a direct shaft assembly, a helical shaft assembly can include the same elements and result in the same operational steps: first opening the wheel extension (via the torsion spring), followed by rotation of the wheel, followed by reverse rotation of the motor gear, which causes the wheel extension to close (via the ratchet and pawl spring lock).

[0051] 20-22 are schematic diagrams of the retraction mechanism of system 100. Shown is drive base 308 on which the elements described above are positioned, including propulsion unit 302, propulsion unit motor 304, flex cable 310, PCB 312, and battery charging contacts 324. Also shown is propulsion unit receptacle 2000, which holds the propulsion unit before it enters the cartridge. Propulsion unit receptacle 2000 is positioned so that the wheel extensions of the propulsion unit are positioned within the cartridge barrel, behind the plunger, when the cartridge is inserted into the drive.

[0052] The flex cable 310 is also referred to herein as the "retraction band 310" because one of its functions is to retract the propulsion unit into the receptacle 2000. The flex cable 310 is typically secured to the propulsion unit at a flex cable-to-motor connection point 2010 on the back of the propulsion unit. When the propulsion unit enters the cartridge, the flex cable retracts into the cartridge along with the propulsion unit.

[0053] In some embodiments, the retraction wheel 2020 is rotated in a first direction by the flex cable as the flex cable is retracted into the cartridge. The retraction wheel 2020 may be spring-activated or motor-activated to then rotate in the opposite direction, thereby retracting the flex cable and providing a retraction mechanism for retracting the propulsion unit from the cartridge. The operation of the retraction wheel, as well as the propulsion unit motor, is typically controlled by the controller 2030. When the propulsion unit is retracted, the controller first activates the propulsion unit motor 304 to close the wheel extensions and separate the wheels from the inner wall of the cartridge. The retraction wheel 2020 then pulls the flex cable, pulling the propulsion unit back into the receptacle 2000. Alternatively, the retraction wheel may have its own motor that receives a rewind signal from the controller to retract the propulsion unit.

[0054] As mentioned above, the controller may also be programmed to receive instructions from an external device, such as a smartphone, via a communications device 2040, which may be incorporated into the controller. The external device may be configured to transmit such instructions, which may include, for example, instructions regarding the amount of fluid to eject at a given time and / or instructions to retreat the propulsion unit. Upon receiving an input indicating the amount of fluid to be expelled, the controller may trigger a signal to the motor to advance the propulsion unit a distance calibrated to expel the commanded amount of fluid (i.e., convert units of volume to units of distance).

[0055] The retracting wheels 2020 may also include coding for an encoder 314 to measure the distance traveled by the propulsion unit, for example, by measuring the degree of rotation of the retracting wheels. The measured distance may be measured both as the propulsion unit moves forward and as the propulsion unit is retracted.

[0056] The flex cable 310 may also include control wires that connect to a power source and / or controller to provide power to the motor (e.g., two wires with a DC voltage difference, such as +5V and 0V) and thereby control the forward or reverse motion of the motor. The connection of the control wires from the flex cable to the motor is indicated by a flex connection 2050 with multiple pins that allows bidirectional control of the motor.

[0057] Details of the flex cable 310 and retractable wheel 2020 can be seen in the perspective view of FIG. 21. The flex cable 310 can have a hole 2110 that fits over the pin 2112 of the retractable wheel. As the flex cable advances into the cartridge, it pulls on the pin of the retractable wheel, thereby rotating the retractable wheel in a forward direction. The retractable wheel is then triggered to rotate in the opposite direction as described above, causing the pin to pull on the flex cable, which in turn pulls and retracts the propulsion unit. Arrow T1 in the figure indicates tension in the flex cable between the pin of the retractable wheel 2020 and the flex cable connection point 2010.

[0058] The retraction wheel may also include an encoding gear 2120 having encoding for measuring degrees of rotation that may be read by encoder 314. The retraction wheel may also include a spring mechanism 2122 for providing force for subsequent retraction of the propulsion unit. The flex cable 310 is typically secured to the drive base at a base connector 2130 that provides signals to the flex cable's control wires as described above. The flex cable is initially folded at a fold 2132 (to allow fluid to be expelled) so that the entire length of the flex cable is long enough to be retracted into the cartridge to the full extent of the cartridge barrel.

[0059] Figure 22 is a perspective schematic view of the base 308 of the drive portion of the system, with the base rotated from the view of Figure 21 to better show the motor connection 2050. As shown, the connection can have four contacts for actuating the motor (typically a stepper motor) in both directions.

[0060] 23 is a perspective schematic view of the base 308 of the drive portion of the system aligned for connection with the delivery portion 130 of the system. As mentioned above, the delivery portion can also have an adhesive bottom that allows the system to be attached to a patient. A releasable adhesive cover 2310 couples the drive portion and delivery portion together and may cover a top adhesive patch that is also located on the delivery portion (the top adhesive patch is hidden from view by the adhesive cover). The delivery portion can also include an interlocking connector 540 (described above with respect to FIG. 5) that interfaces with the drive portion.

[0061] As shown in FIG. 24, the interlocking connector 540 of the delivery portion 130 typically includes two elements: a interlocking plate 2410 and one or more sets of axial snaps 2420 (or similar interlocking connectors).

[0062] As shown in FIG. 25, the base 308 has one or more coupling sensors 2510 (eg, spring pins) and snap stops 2520 configured to interconnect with respective axial snaps 2420 .

[0063] 26A is a schematic diagram showing a top view of the mating connector 540 coupled to a complementary element on the base 308 of the drive unit. As shown, the coupling plate 2410 is in contact with the coupling sensor 2510. The coupling sensor 2510 is typically connected to a controller, which determines whether or not there is continuity between the coupling sensors. Continuity indicates to the controller that the coupling plate is in place and therefore the drive and delivery unit are engaged.

[0064] The driver and delivery unit may be configured to be detachable from one another to allow insertion of a new prefilled cartridge. A user first inserts the new cartridge into the delivery unit, piercing the seal (i.e., "septum") of the cartridge to allow fluid to flow through the tubing of the delivery unit and to the hypodermic needle. The user then attaches the driver to the cartridge and presses the driver and delivery unit together (e.g., so that the mating connector and axial snap interconnect). The process of connecting the driver and delivery unit may also press a propelling unit against the plunger of the cartridge to prime the fluid tubing and hypodermic needle.

[0065] The controller is typically programmed to identify the connection by sensing electrical continuity indicated by the coupling sensor and, in response, trigger the motor to deploy the wheel extensions and advance the propulsion unit into contact with the plunger.

[0066] The controller is also typically further programmed to identify disconnection of the drive unit from the delivery unit by sensing a lack of electrical continuity indicated by one or more coupling sensors 2510, and in response, trigger a motor to fold the wheel extensions, thereby triggering the retraction wheels to retract the propulsion unit (typically by releasing the spring-loaded torque of the retraction wheels). The coupling sensor may include one or more electrical contacts in one part (either the delivery unit or the drive unit) and one or more conductive elements in the other part configured to measure contact between the drive unit and the delivery unit. Alternatively, or additionally, the coupling sensor may include a Hall sensor in one part aligned with a magnet in the other part, or a near-field communication (NFC) sensor in one part aligned with an N-tag in the other part. These or other known coupling sensors can be used to detect disengagement between the drive unit and the delivery unit and trigger retraction of the propulsion unit.

[0067] Figure 26A also shows the complete locking mechanism 2610, which provides a lock through the interconnection of snap 2420 and stopper 2520, helping to maintain the connection between the driver and delivery section. Figure 26B shows the same interconnection from a perspective view. This interconnection is typically designed so that the two parts release when the driver is lifted from the delivery section or when the second section is bent under the driver.

[0068] 27A and 27B are schematic diagrams of the adhesive mechanism of system 100. As mentioned above, delivery unit 130 typically has an adhesive bottom surface 220 for attaching the system to the user's body after the drive unit and delivery unit are connected. Additionally, the delivery unit can have an upper adhesive patch 2700 to ensure a secure connection between the drive unit and delivery unit.

[0069] As shown, the peel-off cover 2310 initially covers the upper adhesive patch 2700. FIG. 27B is a side view of the delivery section, showing that the peel-off cover can be folded over, covering the upper adhesive patch 2700 and extending to cover the underside of the adhesive patch on the delivery section. When the peel-off cover is in position to cover the upper adhesive patch, the driver can be secured to the delivery section by the interlocking connector described above. (The peel-off cover should not be removed before connecting the driver, as this would expose the upper adhesive patch and prevent the user from sliding the two components together.) After the components are connected, the user can pull the peel-off cover in the direction of arrow A1, thereby exposing the upper adhesive patch 2700 and allowing the two components to attach. FIGS. 28A and 28B show an exposed view of the upper adhesive patch. When the upper adhesive patch 2700 is exposed, the two components are typically already joined and the upper adhesive patch is hidden from view.

[0070] As shown in Figures 28A and 28B, after the driver and delivery sections are attached to one another and the peel-off cover is removed from between the two sections, a user can peel the peel-off cover off the underlying adhesive patch by pulling the peel-off cover in the direction of the arrow shown as A2. The adhesive bottom surface 220 is then exposed, and the system can be applied to a patient's body, as shown in Figures 29A and 29B. Typically, as the system is pulled from the patient's skin, the delivery section is bent under the driver section, causing the adhesive patch connecting the two sections to separate from one another.

[0071] FIG. 30 is a schematic diagram of a mechanism illustrating priming of the needle / cannula 230 of the system 100. The underside 220 of the delivery portion 130 includes an opening 232 for injection of the needle / cannula 230. Prior to injection, the system is configured to advance a propelling unit relative to the plunger to squirt a small amount of fluid 420, e.g., a single drop of fluid, to “prime” the system and ensure no air remains in the tubing or needle / cannula prior to injection. To provide a user indication of priming, the underside 220 of the delivery portion can include a litmus patch 3002, such as a small patch of litmus paper. The litmus patch can also be provided attached to a peel-off adhesive cover 2310. The litmus patch absorbs the droplets expelled by priming and “responds” by indicating the absorption of the fluid, e.g., by changing color, thereby indicating proper priming. The controller can be configured to receive user input confirming priming in order to proceed with the operation (e.g., injection and fluid expulsion).

[0072] FIGS. 31A-31C are schematic diagrams of a mechanism for sensing skin contact in the system. As shown in FIG. 31A, the drive unit can include a proximity sensor 3100. This sensor is configured to measure proximity and / or contact between the system and the patient's skin. As shown in FIG. 31B, when the drive unit and delivery unit are mated, the proximity sensor is located above a window 3102 on the underside of the delivery unit. FIG. 31C shows the system without the adhesive release cover 2310. The sensor is typically connected to the controller described above and provides a signal to the controller indicating skin contact (i.e., "proximity"). The controller may be configured to wait for such a signal while confirming system attachment before proceeding with subsequent steps (e.g., needle / cannula injection, fluid evacuation, etc.). A detachment signal is then obtained when the system is detached from the skin. The controller can be configured to respond to such a detachment trigger signal by retracting the propulsion unit to its initial position within the propulsion unit receptacle (e.g., by triggering the retraction of the flex cable described above). As mentioned above, this retraction ensures that the propulsion unit is not in the delivery section when the drive section is disconnected.

[0073] FIGS. 32A-32E are schematic diagrams of the mechanism for the drive plate configuration of the propulsion unit. As shown in FIG. 32A, the plunger of cartridge 120 can have multiple configurations, such as plunger 400A and plunger 400B. In most configurations, the plunger face has a protrusion 3202 that can absorb some of the pressure from propulsion unit plate 810 and potentially reduce the consistency of operation. To overcome this problem of the plunger protrusion, the plate may be provided with a groove-like cutout, shown as a full cutout 3210 in FIG. 32B and as a partial cutout 3214 in FIGS. 32D and 32E. As shown in FIG. 32C, the end of the plate with the full cutout 3210 may be supported by an end support 3212.

[0074] 33A, 33B, 34A, and 34B are schematic diagrams of a mechanism for forming a seal between the driver 110 and delivery portion 130 when they are mated and enclose the cartridge 120. As shown in FIGS. 33A-33B, the driver cartridge port 320 may include a rigid circular sleeve 3302 (e.g., ceramic or metal), and the cartridge delivery end port 510 may include a flexible circular seal 3304. The sleeve and seal enclose the cartridge when the cartridge is inserted into each portion. As shown in FIGS. 34A-34B, the driver and delivery portion interconnection partially inserts the sleeve between the cartridge and seal when the two portions are locked together, preventing fluids and gases from entering the driver.

[0075] Usage example

[0076] Example 1, i.e., the first exemplary embodiment of the invention described herein, is a system including: 1) a propulsion unit (302) for driving a plunger (400) within a barrel (410) of the cartridge (120) to expel a fluid (420) from a delivery end (430) of the cartridge; 2) a driver (110) including a driver cartridge port (320) configured to receive the plunger end (440) of the cartridge and including a propulsion unit receptacle (2000) configured to hold a propulsion unit through which the propulsion unit enters the cartridge barrel; 3) A delivery portion (130) including a cartridge delivery end port (510) configured to receive the delivery end of the cartridge and expel fluid from the cartridge when the propulsion unit drives the plunger forward.

[0077] Example 2 includes the features of example 1, and the propulsion unit further includes: 1) a motor (304) having a motor shaft (800) arranged coaxially with the cartridge; 2) a motor shaft gear (1002, 1400) attached to the motor shaft; and 3) a plurality of wheel extensions (304, 1510) arranged around the motor shaft, each wheel extension including a secondary gear (1006, 1620), one or more wheels (306), and a wheel gear (1020) attached to one or more wheel axles (1100, 1410). Rotation of the motor shaft in a first direction deploys the wheel extensions until a wheel of the plurality of wheel extensions contacts an inner wall (412) of the cartridge. Once the wheel contacts the inner wall of the cartridge, rotation of the motor shaft in the first direction rotates the wheel contacting the inner wall, propelling the propulsion unit forward.

[0078] In Example 3, Example 2 includes the additional feature that the secondary gear of each wheel extension is configured to mesh with the motor shaft gear and a respective wheel gear of a wheel of the wheel extension.

[0079] In example 4, either example 2 or example 3 includes the additional feature that the plurality of wheel extensions are arranged substantially symmetrically about the motor shaft.

[0080] In Example 5, any of Examples 2-4 includes the additional feature that the motor is controllable to rotate in a reverse direction opposite to the first direction, and each wheel extension further includes a ratchet gear (1640) and pawl spring (1642) that lock during backward rotation of the wheel, and after the ratchet gear and pawl spring lock, rotation of the motor shaft in the reverse direction folds the wheel extension.

[0081] In example 6, any of examples 2-5 includes the additional feature of a spring (1520) that applies a torque that deploys the wheel extensions away from the motor shaft when the motor rotates in the first direction. In example 7, the spring is a torsion spring connected to the wheel extensions and applies a torque that deploys the wheel extensions.

[0082] In Example 8, any of Examples 2-7 includes the additional feature that the secondary gear (1620) rotates on an axis (1630) perpendicular to the primary axis such that rotation of the wheels when in contact with the inner wall of the cartridge advances each wheel in a direction parallel to the motor shaft. In Example 9, the motor shaft gear is a worm gear (1400).

[0083] In Example 10, any of Examples 2-7 above includes the additional feature that the propulsion unit includes a stationary gear (1012) attached to the motor and from which the motor shaft extends. Each wheel extension also includes a gripping gear (1010) configured to rotate with the wheel extension's respective secondary gear and meshing with the stationary gear (1012). The wheel gear of the wheel extension is attached to an axle (1100) inclined less than 90 degrees relative to the motor shaft, such that rotation of the wheel when in contact with the inner wall of the cartridge advances the wheel extension spirally within the cartridge barrel.

[0084] In Example 11, any of the above examples includes the additional feature of a controller (2030) configured to receive an input indicative of a fluid volume and, in response, trigger the motor to deliver a signal that advances the propulsion unit a distance calibrated to eject the indicated fluid volume.

[0085] In Example 12, any of the above examples includes the additional feature of a flex cable (310) connecting the propulsion unit to a retraction mechanism (2020) of the drive section. The retraction mechanism is configured to be triggered to pull the flex cable, retracting the propulsion unit into the drive section for reuse.

[0086] In Example 13, the features of Example 12 are further enhanced by a retraction mechanism including a spring-loaded wheel (2020).

[0087] In Example 14, the features of any of Examples 12-13 further include an encoder (314), wherein the retraction mechanism has coding readable by the encoder, and the encoder measures a distance traveled by the propulsion unit and a corresponding volume of ejected fluid based on a displacement of the flex cable.

[0088] In Example 15, the features of any of Examples 12-14 further include a coupling sensor (324) configured to measure contact between the driver and the delivery portion and trigger retraction of the propulsion unit when the driver and delivery portion separate.

[0089] In Example 16, the features of example 15 further include a coupling sensor configured to trigger folding of the wheel extensions of the propulsion unit prior to triggering retraction of the propulsion unit.

[0090] In Example 17, any of the features of Examples 15-16 further include a controller configured to receive a first signal from the coupling sensor indicating disengagement of the drive system and the delivery system, and in response emit a second signal that triggers retraction of the propulsion unit.

[0091] In Example 18, the features of any of Examples 15-17 further include a coupled sensor having one or more electrical contacts on the drive section and one or more complementary conductive elements on the delivery section, or a coupled sensor having a Hall sensor on the drive section and a magnet on the delivery section, or a coupled sensor having an NFC sensor on the drive section and an N-tag on the delivery section, to detect disengagement of the drive section from the delivery section and trigger retraction of the propulsion unit.

[0092] In Example 19, the features of any of Examples 12-18 are further including: the flex cable configured to provide power from the power source (322) to the motor.

[0093] In Example 20, the features of any of Examples 1-19 further include a locking mechanism (2610) configured to lock the driver and delivery portion together and unlock when the delivery portion is bent below the driver portion.

[0094] In Example 21, the features of Example 20 are included, further including a locking mechanism having an axial stopper disposed on the drive portion and interlocking with the axial snap on the delivery portion.

[0095] In Example 22, the features of any of Examples 1-21 further include an adhesive patch (2700) for attaching the driver to the delivery portion. The adhesive patch is covered by a folded adhesive cover (2310) to prevent adhesion between the driver and delivery portion before the driver is aligned over the delivery portion, and the folded adhesive cover is removable by pulling to expose the adhesive patch when the driver is aligned with the delivery portion.

[0096] In Example 23, the features of Example 22 are further included: the adhesive patch is a first adhesive patch; a second adhesive patch (220) is provided for attaching the delivery portion to the patient's skin; and the folded adhesive cover is removable from the second adhesive patch before or after being removed from the first adhesive patch.

[0097] In Example 24, the features of any of Examples 1-23 further include: the cartridge is made of glass; the propulsion unit has wheels for advancing the propulsion unit into the cartridge barrel; and the wheels are made of a material having a coefficient of friction (COF) with glass greater than 0.05.

[0098] In Example 25, the wheel material is one of: machinable glass-ceramic, tetragonal zirconia polycrystalline, ZrO-YO, zirconia (ZrO), aluminum oxide-alumina (AlO), silicon carbide (SiC), stainless steel, nickel (Ni), glass-reinforced plastic, or glass.

[0099] In Example 26, the features of any of Examples 1-25 further include: the fluid is a therapeutic agent; and the delivery portion includes a tube (520) connecting the fluid delivery end to a needle / cannula (230) for injection into a patient.

[0100] In Example 27, the features of any of Examples 1-26 further include an underside of the delivery portion having an opening (232) for the needle / cannula (230), and a litmus patch (3002) covering the opening and configured to respond (e.g., be visible) to the release of fluid during priming of the system.

[0101] In Example 28, the features of any of Examples 1-27 further include a proximity sensor (3100) configured to measure proximity and / or contact between the system and the patient's skin and to issue an alarm and / or trigger retraction of the propulsion unit to an initial position within the receptacle when the system moves away from the patient's skin.

[0102] In Example 29, the features of example 28 are included, further including a controller configured to receive a first signal from the proximity sensor indicating application of the system to the patient's skin, and in response, emit a second signal indicating effective application.

[0103] In Example 30, the features of any of Examples 1 to 29 further include a propulsion unit having a drive plate (810) with one or more notches (3210, 3214) positioned to contact the plunger when the propulsion unit drives the plunger and avoid protrusion of the plunger.

[0104] In Example 31, the features of any of Examples 1-30 further include: the driver cartridge port has a rigid sleeve surrounding the cartridge; and the cartridge delivery end port includes a flexible seal surrounding the cartridge. An interconnection between the driver and delivery portion inserts the sleeve and cartridge into the seal, preventing fluids and gases from entering the driver.

[0105] It is to be understood that the scope of the present invention includes variations and modifications not disclosed in the prior art, which would occur to one skilled in the art upon reading the foregoing description. Although the present invention has been described in detail, variations and modifications will nevertheless be apparent to those skilled in the art that do not depart from the teachings of the present invention. Such variations and modifications are deemed to be within the scope of the present invention and the appended claims.

[0106] It will be readily apparent that the various methods and algorithms described with respect to the controller may be implemented by appropriately programmed general-purpose computers and other types of computing devices. Furthermore, programs implementing such methods and algorithms may be stored and transmitted in numerous ways and using a variety of media. In some embodiments, hardwired circuitry or custom hardware may be used in place of or in combination with software instructions to implement the processes of various embodiments. Thus, embodiments are not limited to any specific combination of hardware and software. Transmission media include coaxial cable, copper wire, and optical fiber, including the wires that comprise a bus coupled to the processor. Transmission media may include or transmit acoustic waves, light waves, and electromagnetic radiation, such as those generated during radio frequency (RF) and infrared (IR) data communications. Instructions may be transmitted from memory to the processor via wireless transmission media and / or may be formatted according to numerous formats, standards, or protocols, such as Bluetooth, TDMA, CDMA, 3G, etc.

[0107] Below is a list of the elements referred to in the above specification of the present invention. [Table 1] JPEG2025534305000003.jpg232166JPEG2025534305000004.jpg227161JPEG2025534305000005.jpg228166JPEG2025534305000006.jpg228162JPEG2025534305000007.jpg234169JPEG2025534305000008.jpg18163

Claims

1. A fluid delivery system (100) comprising: a propulsion unit (302) for driving a plunger (400) in a barrel (410) of the cartridge (120) to expel a fluid (420) from a delivery end (430) of the cartridge; a driver (110) including a driver cartridge port (320) configured to receive a plunger end (440) of the cartridge and including a propulsion unit receptacle (2000) configured to hold a propulsion unit, through which the propulsion unit enters the cartridge barrel; a delivery portion (130) including a cartridge delivery end port (510) configured to receive the delivery end of the cartridge and release fluid from the cartridge when the propulsion unit drives the plunger forward.

2. 10. The system of claim 1, wherein the propulsion unit further comprises: a motor (304) having a motor shaft (800) coaxially disposed with the cartridge; a motor shaft gear (1002, 1400) attached to the motor shaft; a plurality of wheel extensions (304, 1510) arranged around the motor shaft, each wheel extension including a secondary gear (1006, 1620), one or more wheels (306), and a wheel gear (1020) attached to one or more wheel axles (1100, 1410); wherein rotation of the motor shaft in a first direction spreads the wheel extensions until the wheels of the wheel extensions contact the inner wall (412) of the cartridge; The system wherein, when the wheels are in contact with the inner wall of the cartridge, rotation of the motor shaft in a first direction rotates the wheels in contact with the inner wall and moves the propulsion unit forward.

3. 3. The system of claim 2, wherein the secondary gear of each wheel extension meshes with the motor shaft gear and the respective wheel gear of the wheel extension.

4. 3. The system of claim 2, wherein said plurality of wheel extensions are disposed substantially symmetrically about said motor shaft.

5. 3. The system of claim 2, wherein the motor is controllable to rotate in a reverse direction opposite to the first direction, and each wheel extension further comprises a ratchet gear (1640) and pawl spring (1642) that locks during backward rotation of the wheel, and after locking of the ratchet gear and pawl spring, rotation of the motor shaft in the reverse direction folds the wheel extension.

6. 3. The system of claim 2, further comprising a spring (1520) that applies a torque that spreads the wheel extensions away from the motor shaft when the motor rotates in a first direction.

7. 7. The system of claim 6, wherein the spring is a torsion spring coupled to the wheel extension and applying a torque to deploy the wheel extension.

8. 3. The system of claim 2, wherein the secondary gear (1620) rotates on an axis (1630) perpendicular to the main axis, such that rotation of the wheels when in contact with the inner wall of the cartridge advances each wheel in a direction parallel to the motor shaft.

9. 9. The system of claim 8, wherein the motor shaft gear is a worm gear (1400).

10. 3. The system of claim 2, wherein the propulsion unit further comprises a fixed gear (1012) attached to the motor and from which the motor shaft extends, and each wheel extension comprises a gripping gear (1010) configured to rotate with the wheel extension's respective secondary gear and meshing with the fixed gear (1012), wherein the wheel gear of the wheel extension is attached to an axle (1100) inclined at less than 90 degrees with respect to the motor shaft, and wherein rotation of the wheel when in contact with the inner wall of the cartridge advances the wheel extension in a spiral motion within the cartridge barrel.

11. 3. The system of claim 2, further comprising a controller (2030) configured to receive an input indicating a fluid volume and, in response thereto, trigger delivery of a signal to the motor to advance the propulsion unit a distance calibrated to eject the indicated fluid volume.

12. 10. The system of claim 1, further comprising a flex cable (310) connecting the propulsion unit to a retraction mechanism (2020) in the drive section, the retraction mechanism configured to be triggered to pull the flex cable to retract the propulsion unit into the drive section for reuse.

13. 13. The system of claim 12, wherein the retraction mechanism comprises a spring-loaded wheel (2020).

14. 13. The system of claim 12, further comprising an encoder (314), wherein the retraction mechanism has coding readable by the encoder, the encoder measuring a displacement of the propulsion unit and a corresponding amount of fluid ejected in response to a displacement of the flex cable.

15. 13. The system of claim 12, further comprising a coupling sensor (324) configured to measure contact between the drive unit and the delivery unit and trigger retraction of the propulsion unit when the drive unit and the delivery unit are separated.

16. 16. The system of claim 15, wherein the coupling sensor is further configured to trigger folding of wheel extensions of the propulsion unit prior to triggering retraction of the propulsion unit.

17. 16. The system of claim 15, further comprising a controller configured to receive a first signal from the coupling sensor indicative of disengagement of the drive system and delivery system, and in response emit a second signal that triggers retraction of the propulsion unit.

18. 16. The system of claim 15, wherein the coupling sensor includes one or more electrical contacts in the drive unit and one or more complementary conductive elements in the delivery unit, or a Hall sensor in the drive unit and a magnet in the delivery unit, or an NFC sensor in the drive unit and an Ntag on the delivery unit to detect separation of the drive unit from the delivery unit and trigger retraction of the propulsion unit.

19. 13. The system of claim 12, wherein the flex cable is further configured to provide power to the motor from a power source (322).

20. 10. The system of claim 1, further comprising a locking mechanism (2610) configured to lock the drive section and delivery section together and unlock when the delivery section is bent below the drive section.

21. 21. The system of claim 20, wherein the locking mechanism comprises an axial stop disposed on the drive portion, the axial stop engaging an axial snap disposed on the delivery portion.

22. 10. The system of claim 1, further comprising an adhesive patch (2700) for attaching the driver to the delivery unit, the adhesive patch being covered by a folded adhesive cover (2310) to prevent the driver and delivery unit from adhering together before the driver is aligned over the delivery unit, and the system being removable when the driver is aligned with the delivery unit by pulling the folded adhesive cover to expose the adhesive patch.

23. 23. The system of claim 22, wherein the adhesive patch is a first adhesive patch and further comprises a second adhesive patch (220) for attaching the delivery portion to the patient's skin, wherein the folded adhesive cover also covers the second adhesive patch, and wherein the folded adhesive cover is removable from the second adhesive patch before or after being removed from the first adhesive patch.

24. 10. The system of claim 1, wherein the cartridge is made of glass, the propulsion unit has wheels for advancing the propulsion unit within the cartridge barrel, and the wheels are made of a material having a coefficient of friction (COF) with glass greater than 0.

05.

25. 25. The system of claim 24, wherein the wheel material is one of the following:

1. Machinable glass ceramics; 2. Tetragonal zirconia polycrystalline, ZrO ２ -Y ２ O ３ ; 3. Zirconia (ZrO ２ ); 4. Aluminum oxide - alumina (Al ２ O ３ ); 5. Silicon carbide (SiC); 6. Stainless steel; 7. Nickel (Ni); 8. Glass-reinforced plastic 9. Glass system.

26. 10. The system of claim 1, wherein the fluid is a therapeutic agent and the delivery portion comprises a tube (520) connecting the fluid delivery end to a needle / cannula (230) for injection into a patient.

27. 10. The system of claim 1, wherein the underside of the delivery portion comprises an opening (232) for the needle / cannula (230), and further comprises a litmus patch (3002) covering the opening and configured to respond to the release of fluid during priming of the system.

28. 10. The system of claim 1, further comprising a proximity sensor (3100) configured to measure proximity and / or contact between the system and the patient's skin and to activate an alarm and / or retract the propulsion unit to an initial position within the propulsion unit receptacle when the system is removed from the patient's skin.

29. 29. The system of claim 28, further comprising a controller configured to receive a first signal from the proximity sensor indicating application of the system to the patient's skin, and in response thereto, emit a second signal indicating effective application.

30. 2. The system of claim 1, wherein the propulsion unit further comprises a drive plate (810) having one or more notches (3210, 3214) positioned to contact the plunger when the propulsion unit drives the plunger and prevent the plunger from protruding.

31. 10. The system of claim 1, wherein the drive cartridge port comprises a rigid sleeve that surrounds the cartridge, the cartridge delivery end port comprises a flexible seal that surrounds the cartridge, and the interconnection of the drive and delivery portion inserts the sleeve and cartridge into the seal to prevent fluids and gases from entering the drive portion.

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