WO2025212544A9

WO2025212544A9 - Cam driven index drive mechanism

Info

Publication number: WO2025212544A9
Application number: PCT/US2025/022390
Authority: WO
Inventors: Andrew Beaupre; Scott Stewart
Original assignee: Becton Dickinson and Co
Current assignee: Becton Dickinson and Co
Priority date: 2024-04-01
Filing date: 2025-03-31
Publication date: 2025-11-06
Anticipated expiration: 2026-10-01
Also published as: WO2025212544A1

Abstract

System includes a syringe-style drug container, reservoir, or chamber containing a medium or fluid which can be dispensed by advancing a plunger disposed inside the container and a ratchet mechanism disposed outside the container driven by a motor to advance the plunger to dispense the medium or fluid out of the container. A drive mechanism can include a double ratchet mechanism actuated using a motor paired with a leadscrew driven syringe pump or a linkage driven syringe pump for advancing a plunger to dispense the medium or fluid in a drug delivery device.

Description

CAM DRIVEN INDEX DRIVE MECHANISM

Background

[0001] Generally, exemplary embodiments of the present disclosure relate to the fields of medication delivery devices. More specifically, exemplary embodiments of the present disclosure relate to medication delivery devices where a stopper or plunger is advanced through a reservoir to dispense medication from the reservoir.

[0002] In the example of medical applications, a patch pump is an integrated device that facilitates infusion therapy for diabetic patients. A patch pump combines most or all of the fluidic components, including the fluid reservoir, pumping mechanism and mechanism for automatically inserting the cannula, in a single housing which is adhesively attached to an infusion site on the patient’s skin, and does not require the use of a separate infusion or tubing set. A patch pump containing insulin adheres to the skin and delivers the insulin over a period of time via an integrated subcutaneous cannula. Some patch pumps may be configured to include wireless communication with a separate controller device, while others are completely self-contained. Such devices are replaced on a frequent basis, such as every three days, particularly when the insulin reservoir is exhausted.

[0003] As patch pumps are designed to be a self-contained unit that is worn by the diabetic patient, it is preferable to be as small as possible so that it does not interfere with the activities of the user. Thus, in order to minimize discomfort to the user, it would be preferable to minimize the overall size of the patch pump. Conventional patch pumps or a syringe-type devices typically include a driving mechanism with a single advancing lead screw inside

1 medium or fluid reservoir or chamber to push, advance, or otherwise apply force on the plunger in order to dispense the medium or fluid out of the chamber.

[0004] An example of a patch pump having single advancing lead screw features is disclosed in

WO2022/261100, published December 15, 2022, the entire disclosure of which is incorporated herein by reference. As illustrated in Figures 1A - 1C, a wearable disposable patch pump 100 can be configured to include a base 102, outer housing 104, and an insertion mechanism 106.

FIG. 1C illustrates a top view, of pump 100 without the outer housing or cover 104, and diagrammatically shows at least some of the various components that can be configured on base

102 of a pump 100 including a pumping mechanism 200 having a motor 202 operatively connected to lead screw 204 by gears including reduction gears 206 and lead screw gear 208 configured to rotate lead screw 204. A plunger assembly 210 is disposed inside barrel 212 such that plunger 210 translates or moves axially with respect to barrel 212 due to rotation of lead screw 204 whereby fluid can be dispensed by rotating the motor 202 forward driving the plunger 210 to move axially with respect to barrel 212 away from proximal end 213 and toward distal end 215 of barrel 212 forcing fluid out of the barrel outlet 107.

[0005] Other mechanisms for advancing a plunger in a barrel described in WO2022/261100 include a linkage mechanism, illustrated in FIG. ID, and a collapsible drive mechanism, illustrated in FIG. IE. As shown in FIG. ID, a pumping device 900, which can be deployed for example hi a pump 100, can comprise a plunger 910 disposed in barrel 912, such that plunger

910 can be advanced axially toward and away from distal end 915 of bar rel 912 by a two linkage mechanism 904 driven through appropriate gearing 920 by a motor (not shown) for example operatively connected at 921. As shown in FIG. IE, a collapsible drive mechanism

2 1200, which can be deployed for example in a pump 100, can include a linkage mechanism

1304 connected to a plunger 1210 disposed in barrel 1212 and driven by a motor (not shown) for example operatively connected at 1207. Tire linkage mechanism can comprise a single linkage or a set of two full linkages 1305 and 1306 and two half linkages 1307 and 1208, where distal ends of half linkages 1307 and 1308 can be joined at, or pivotally coupled to, plunger

1210, for example at proximal end 1415 of plunger 1210, for example via a loose pin 1420.

Proximal ends of half linkages 1307 and 1308 can be joined at, or pivotally coupled to, distal ends of respective full linkages 1305 and 1306, for example via respecti ve loose pins 1421 and

1422. Full linkages 1305 and 1306 crisscross and can be joined, or pivotally coupled, essentially at the centers thereof, for example by means of a loose pin 1423. Proximal ends of fiill linkages 1305 and 1306 are joined at, or pivotally coupled to, the driveshaft 1207 at opposing left 1302 and right 1301 hand female screw threads, respectively, for example by means of respective loose pins 1425 and 1424.

[0006] In order to further minimize the size of the patch pump, its constituent parts, such as driving mechanisms, should be reduced as much as possible without compromising the accuracy and reliability’ of device or its feature set.

Summary of Disclosure

[0007] The matters exemplified in this description are provided to assist in a comprehensive understanding of exemplary embodiments of the disclosure. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the disclosure.

Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0008] As would be readily appreciated by skilled artisans in the relevant art, while descriptive terms such as “medium,” “medicament,” “stopper,” “plunger,” “arm,” “syringe,” “motor,” “pawl,” “ratchet,” “gear,” “teeth,”, “flange,” “cam,” “dwell,” “wall,” “top,” “side,” “bottom,” “upper,” “lower,” “proximal,” “distal,” “container” “reservoir,” “chamber,” and others are used throughout this specification to facilitate understanding, it is not intended to limit any components that can be used in combinations or individually to implement various aspects of the embodiments of the present disclosure.

[0009] Exemplary embodiments of the present disclosure provide system components for a drug delivery device, such as a patch pump, can provide a pumping mechanism that, for example and without limitation, can be functional in a wider range of temperature settings, for example at higher temperatures, and can allow for a more compact design of various syringe driven pumps.

[0010] Exemplary implementations of embodiments of the present disclosure provide combinations of various feature of a drive mechanism including a ratcheting mechanism actuated using, for example a bi-directional, motor paired, for example, with a leadscrew driven syringe pump or a linkage dri ven syringe pump, for advancing a plunger to dispense the medium or fluid in a drag delivery device. [0011] According to exemplary embodiments of the present disclosure, a system includes a syringe-style drug container, reservoir, or chamber containing a medium or fluid which can be dispensed by advancing a plunger disposed inside the container facing, or in contact with, or proximal to, the medium inside the container, and a double ratchet mechanism, for example a dual layer cam ratchet mechanism, disposed outside the container driven by a motor to advance the plunger to dispense the medium or fluid out of the container.

[0012] According to exemplary embodiments of the present disclosure, certain space savings and/or a more compact design of various syringe driven pumps can, but is not required to, be achieved by utilizing exemplary implementations of a mechanical drive mechanism that has, for example and without limitation, a parallel axial alignment between a ratcheVlead screw and a motor driver. For example, in such an implementation, a motor may be arrange to take up the length of space adjacent to the syringe pump reservoir.

[0013] In exemplary⁷ implementations of embodiments of the present disclosure, in example proposed design embodiment only a ratchet gear can be configure to contribute directly to functional increment tolerancing.

[0014] Further, in exemplary implementations of the embodiments of present disclosure, a cam driven index drive mechanism can be paired with a leadscrew driven syringe pump, where the cam driven index drive mechanism can offer, for example and without limitation, a safety feature when used in conjunction with a leadscrew driven syringe pump in that the mechanism can mitigate the possibility of a runaway fluid infusion in the event of an error state in which the driving motor is left running. [0015] In yet further exemplary' implementations of embodiments of the present disclosure, a ratchet advancement can be facilitated using a metal spring clip.

[0016] In yet further exemplary implementations of embodiments of the present disclosure, a cam follower and an element that puts tension on the cam follower can be implemented as a single component.

[0017] In exemplary implementations of embodiments of the present disclosure, conversion of rotational to linear motion can be achieved using a cam surface driven with a bi-directional motor.

[0018] In exemplary implementations of embodiments of the present disclosure, double acting spring arms can be used to replace a ratchet locking pawl.

[0019] Exemplary' implementations of embodiments of the present disclosure can utilize a used double-ratchet with offset gear teeth.

[0020] Exemplary' implementations of embodiments of the present disclosure can utilize variable thickness metal spring clip.

[0021] In exemplary implementations of embodiments of the present disclosure, a leadscrew can be configures as either fused to a ratchet or interfaced as two separate components.

Brief Description of Drawings [0022] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, embodiments of the present disclosure are described as follows.

[0023] Figures 1 A and IB are examples of perspective views of an exterior of a device according to exemplary embodiment of the present disclosure.

[0024] Figures 1C, ID and IE are examples of perspective views of components of device configurations that can be optionally implemented with various configurations of exemplary embodiment of the present disclosure.

[0025] Figure 2A illustrates a top view of a combination of system components of a device according to exemplary embodiments of the disclosure.

[0026] Figures 2B, 3 and 4A diagrammatically illustrate views of combinations of system components according to exemplary embodiment of the present disclosure.

[0027] Figure 4B illustrates another top view of a combination of system components of a device according to exemplary embodiments of the disclosure

[0028] Figure 5 illustrates a detail of certain components of a device according to exemplary embodiments of the disclosure.

[0029] Figure 6 illustrates examples of various configurations of a components of a device according to exemplary embodiments of the disclosure.

[0030] Figure 7 A diagrammatically shows a perspective partial view of components according to exemplary implementations of embodiments of the disclosure. [0031] Figure 7B diagrammatically shows a side partial view of components according to exemplary implementations of embodiments of the disclosure.

[0032] Figures 7C and 7D diagrammatically shows side views of components according to exemplary implementations of embodiments of the disclosure.

[0033] Figures 8A and 8B diagrammatically show perspective views of components according to exemplary implementations of embodiments of the disclosure.

[0034] Figures 8C and 8D diagrammatically show side views of components according to exemplary implementations of embodiments of the disclosure.

[0035] Figure 9 diagrammatically shows perspective views of components according to exemplary implementations of embodiments of the disclosure.

[0036] Figures 10A and 10B diagrammatically show perspective views of components according to exemplary implementations of embodiments of the disclosure.

[0037] Figure 11 illustrates in a block diagram an example of a configuration of design elements according to exemplary implementations of example disclosed embodiments.

[0038] Figure 12 illustrates in a block diagram an example of another configuration of design elements according to exemplary implementations of example disclosed embodiments.

[0039] Figure 13 diagrammatically shows a perspective view of components according to exemplary implementations of embodiments of the disclosure.

[0040] Figure 14 diagrammatically shows a side partial view of components according to exemplary implementations of embodiments of the disclosure. [0041] Figures 15A and 15B diagrammatically show perspective views of components according to exemplary’ implementations of embodiments of the disclosure.

Detailed Description of Disclosure

[0042] Exemplary embodiments of the present disclosure provide systems, devices, components, and methodologies comprising, without limitation, various design of a ratcheting mechanism, for example driven by a back-and-forth rotation of a motor such as a bi-directional motor.

[0043] Figure 2A, illustrates in a conceptual block diagram a top view of internal component configuration according to an exemplary embodiments of the present disclosure that can be implements for example and without limitation in a wearable disposable patch pump, such as a pump 100. As diagrammatically shown in Figure 2A, in exemplary implementations at least some of the various components that can be configured on a base, or a structure, 2000 include a motor 2002 operatively connected to lead screw 2004 by a cam driven ratchet mechanism 2010 configured to rotate lead screw 2004. In exemplary implementations, a portion of lead screw 2004, such as a portion comprising lead screw gear 2008, can be configured outside of barrel 2012 in order to operationally connect lead screw 2004 to motor 2002. A reservoir/pump assembly 2012, such as for example and without limitation shown hi Fig. 1C and 3B, can include a plunger 3005 disposed inside a barrel 2012 such that the plunger translates or moves axially with respect to the barrel due to rotation of lead screw 2004 whereby fluid can be dispensed by rotating the motor 4006 driving the plunger to move axially with respect to the barrel, away from its proximal end and toward its distal end forcing fluid out of the barrel outlet.

[0044] As illustrated in the example of Figure 2A, and in more diagrammatic detail in Figure 2B, in an exemplary implementation of the disclosed example embodiments, mechan ism 2010 can be configured to comprise: a cam, for example double tap cam, 2006 driven by a motor 2002 connected to a power source (for example, a battery) 2014; and a ratchet, for example a double tap ratchet, 2008, configured to rotate a lead screw 2004. In exemplary implementations, lead screw 2004 may be unitarily formed from non-metallic and metallic materials, such as polymeric materials, including, but not limited to, thermoplastics, stainless steels or other metallic alloys. According to exemplary implementations of example embodiments, the ratchet gear 2008 can be a single part composed of two identical sets of gear teeth aligned axially but rotationally biased, for example 14 tooth, from each other.

[0045] As further illustrated, in Figure 2B, in an exemplary implementation of the disc losed design a vertical plate 2020, such as a formed baseplate (with various alignment features), can be provided in addition to, or integral with, structure 2000 for accommodating a ratchet gear 2008, a cam, for example a single-part dual cam driver, 2006 actuated by a bi-directional motor 2002, a metal spring clip 2022 (for example a single clip with two arms, or two one-arm clips), a clip bias pin 2024, a cam alignment pin (not visible), and one or more stopper pins 2028, 2028A can be used to constrain and/or guide the aforementioned components.

[0046] Referring to a non-limiting illustration of Figure 3, ratchet 2008 can be configured as a ratchet gear 3008 comprising two sets of gear teeth 3032, 3034 that can be split via a central circular flange 3036 which extends past the maximum diameter of the gear teeth and separates and guides the two arms 3022, and 3024 of the metal spring clip, such as a clip 2022. Although not illustrated, according to an exemplary implementation, the ratchet gear 2008 may be combined or fastened to an axially aligned set-screw.

[0047] Referring to non-limiting illustrations of Figures 4A and 4B, according to further exemplary implementations of example embodiments, cam 2006 can be configured as a singlepart dual cam driver 4006 that can be composed of two cam surfaces 4010, 4012 which are axially aligned but symmetrically mirrored. In an exemplary non-limiting implementation, the (3) single-part dual cam driver 4006 can have an effective rotation angle of approximately 315°. For example, the motion profile of the single-part dual cam driver 4006 can be broken down into 3 phases:

• Phase I: A 77.5° Dwell, in which the single-part dual cam driver 4006 is rotating but the metal spring clip 2022 is not advancing or retracting.

• Phase 2: A 160° constant acceleration motion, in which the single-part dual cam driver 4006 is rotating and the metal spring clip 2022 is advancing or retracting, depending on the arm

• Phase 3: A 77.5° Dwell, in which the single-part dual cam driver 4006 is rotating but the metal spring clip 2022 is not advancing or retracting.

[0048] Referring to non-limiting illustrations of Figure 4B, various components of mechanism 2010, can be configured on a base 3002 of a pump 3000 according to exemplary embodiments of the disclosure, were for example and without limitation a distal end of barrel 2012 may include an endcap 3070 to facilitate connection of barrel 2012 to an insertion mechanism, such as a mechanism 106, for example via port or tube 3072, to dispense medium or fluid out of barrel 2012 by displacement of plunger 2005. Endcap 3070 can also be configured to fac ilitate connection of barrel 2012 to fill port or inlet 3200, for example via a tube such as tube 3074, to fill barrel 2012 with medium or fluid. In an exemplary implementation, motor 2002 can be controlled by a microprocessor having a memory, such as a microchip mounted on a PCB 300, or other controlling method.

[0049] Referring to a non-limiting illustration of Figure 5, according to yet further exemplary implementations of example embodiments, a cam 2006, such as a single-part dual cam driver 4006, can be constrained via a mechanical interference between features protruding from the cam 4006, such as a single-part dual cam driver 4006, and for example two stopper pins 2028 adjacent to the cam driver 4006. A “D” shaft motor interface feature 5050 can be axially aligned with each of the cam surfaces 4010, 4012.

[0050] In an exemplary implementation, as the single-part dual cam driver 4006 is driven with a motor, the cam surfaces 4010, 4012 can push against each of the arms 3022, 3024 of the metal spring clip, such as clip 2022. Because the two cam surfaces 4010, 4012 are symmetrically mirrored, rotation of the, for example single-part, dual cam driver 4006 causes one arm, for example 3022 of a metal spring clip 2022 to advance while the other arm, for example 3024, retracts. An advancing arm 3022 of the metal spring clip 2022 pushes on the engaged ratchet gear tooth, for example of gear teeth 3034. Concurrently, the retracting arm, for example 3024, of the metal spring clip 2022 springs back and passes over the succeeding tooth, for example of gear teeth 3032, resetting the mechanism. For example and without limitation, this resetting motion can eliminate the need for a secondary ratchet pawl used to eliminate the possibility of ratchet back-drive and decreases the complexity and cost of the mechanism.

[0051] As illustrated for example and without limitation in Figure 2B, in an example implementation, a clip bias pin 2024 can be positioned to interfere slightly with the arms 3022, 3024 of the spring clip 2022 when advanced fully, and can provide a counter-force to help guide the arms to reset position during retraction. In another example implementation, this pin 2024 may be removed, for example in alternate design embodiments, depending on the stiffness and shape of the metal spring clip 2022.

[0052] According to exemplary implementations of disclosed embodiments, the stiffness of pushing arms 3022, 3034 of clip 2022 can be varied as required. For example and without limitation, as illustrated in the example of Figure 6, thicknesses may be increased or decreased during manufacturing to vary the stiffness of the pushing arms 3022, 3034 of a metal spring clip 2022. As an example, spring steel stamped metal spring clip arms 3022, 3034 may be of the same thickness throughout (A), or hemmed flat and fused such that the length of arm between the teeth of the ratchet gear and the single-part dual cam driver is roughly twice as thick as the rest of the clip, for example with ham 6002 up to first bend radius (B), or ham 6004 past first bend radius (C).

[0053] According to exemplary implementations, disclosed example design embodiments can comprise a cam alignment pin which is axially aligned with the motor “D” shaft input feature of the cam 2006, such as a single-part dual cam driver 4006. According to other exemplary' implementations, example embodiments of the design may not require an axial alignment pin depending on positional tolerances and motor alignment and fastening methods. For example, as illustrated in the example of Figure 2A, a third stopper pin 2028A can be used to hold the metal spring clip 2002 against the alignment features 2021 of the formed baseplate 2020.

[0054] Referring to non-limiting illustration of Figure 7A - 7D, according to exemplary implementations, disclosed example design embodiments can comprise a cam/motor stop switch 7000 configured with respect to, or as a part of mechanism 2010 where conductive elements, such as conductive spring, 7200 interface with a clip 7022 and cam 7006. In an example implementation, conductive elements 7200 can be disposed on base 7002 of a pump and can interfaces with cam 7006 via a connection element, for example an electrical bush, 7004 connected to one of conductive elements 7200. Clip 7022 can be, or can comprise, a metallic indexing portion, and can be connected to another of conductive elements 7200 not connected to connection element 7004. Cam 7006 can comprise an electrically conductive, for example metallic, portion 7006A and an electrically non-conductive, for example plastic, portion 7006B, contacting connection element 7004. As shown in a non-limiting examples of Figure7C, isolated switch current path components can comprise a current flow 7500 created between one of conductive elements 7200 connected to source 7504 and another of conductive elements 7200 connected to ground 7502 (and, for example also connected to clip 7022), when electrically conductive cam portion 7006A contacts connection element 7004 connected to ground 7502 and conducts. On the other hand, as shown in a non- limiting example of Figure 7D, no current flow path is created when electrically non-conductive cam portion 7006B contacts connection element 7004.

[0055} Referring to non-limiting illustrations of Figure 8A - 8D, as well as for example Figure 7A, according to exemplary implementations, disclosed example design embodiments can comprise a ratchet encoder 8000 where ratchet 8008 and conductive elements 8200 can be configured with respect to, or as a part of mechanism 2010. In an example implementation, ratchet 8008 can comprise conductors 8100, such as one or more pins 8102 that path through ratchet gear 8034, 8032, and conductive elements 8200 can comprise two conductive elements 8200A and 8200B, which may or may not be connected directly to a PCB, such as PCB 300. Conductive elements 8200 can be disposed on base 7002 of a pump and can interfaces with ratchet 8008, as illustrated in non-limiting example of Figures 7A and 8A-8B. As further illustrated in non-limiting examples of Figures 8C and 8D, as ratchet 8008 rotates conductors 8100 connect conductive elements 8200A and 8200B causing an electrical short (“ON”) 8500 (Figure 8B), and as ratchet continues to rotate, conductors 8100 disconnect from conductive elements 8200A and 8200B such that conductive elements 8200A and 8200B connect to a non- conductive, such as plastic, portion 8110 of ratchet 8008 causing an open circuit (“OFF”) 8600 (Figure 8C).

[0056] Referring to a non-limiting example of Figure 9, according to an exemplary implementation, conductive elements 9200 disposed on either side of ratchet 8008 can be, or can comprise, conductive, for example spring-loaded, metal clips 9200A and 9200B, which may or may not be connected directly to a PCB, such as PCB 300. Clips 9200A and 9200B can be disposed on base 7002 instead of conductive springs 8200A and 8200B (see example of Figure 8A), and can be configured with respect to ratchet 8008 such that as ratchet 8008 rotates conductors 8100 connect conductive elements 9200A and 9200B causing an electrical short (“ON”) 8500 (see example of Figure 8B), and as ratchet continues to rotate, conductors 8100 disconnect from conductive elements 9200A and 9200B instead connecting to a non-conductive portion 8200 of ratchet 8008 causing an open circuit (“OFF”) 8600 (see example of Figure 8C).

[0057] Referring to Figure 10A and 10B, according to an exemplary implementation, ratchet 10808 can comprise a ratchet body 10008 and conductor 10200, such as for example a tube cut into a shape of a crown. Tire tines or leads 10201 of conductor 10200 can be passed through corresponding opening 10801 of the ratchet body 10008, electrically joining proximal side 10010 and distal side 10020 of ratchet body 10008, where for example tines 10201 and non- conductive portions 10202 between tines 10201 can be on proximal side 10010, and conductive ring 10203 can be on distal side 10020. The proximal and distal sides of ratchet body 1008 can be separated by two sets of gear teeth 10032, 10034 that can be split via a central circular flange 10036 (see, for example, Figure 3), and openings 10801 for passing through tines 10201 can be through the gear teeth 10032,10034 and flange 10036 structures. The tines 10201 may or may not be used as the radial bearing surface of the ratchet 10808. In an exemplary implementation, tines 10201 may be folded inwards at the tips to form a snap feature, for example over end of proximal side 10010, holding the conductor 10200 in place with respect to ratchet body 10008 after sliding through openings 10801 in the ratchet body 10008 during assembly. According to exemplary implementations, number and size of tines 10201 may be increased or decreased to accommodate manufacturing methods and/or design requirements.

[0058] In exemplary implementations, clips 9200A and 9200B, or conductive springs 8200A and 8200B, can be disposed on base 7002 and can be configured with respect to ratchet 108008 such that as ratchet 108008 rotates conductor tines 10201 and ring 10203 connect conductive elements 9200 / 8200 causing an electrical short (“ON”) 8500 (see example of Figure 8B), and as ratchet continues to rotate, tines 10201 disconnect from one of conductive elements 9200 /

8200 instead connecting to a non-conductive portion 10202 of ratchet 108008 causing an open circuit (“OFF”) 8600 (see example of Figure 8C).

[0059] Figure 11 illustrates in a block diagram an example of a configuration of design elements according to exemplary' implementations of example disclosed embodiments, where in an exemplary implementation a drive ratchet encoder 11000 can comprise for example a ratchet wheel rotation coupled switch 11002, including for example an encoder 8000 (see for example Figure 8B) or an encoder 10808 (see for example Figure 9), and a motor encoder 11100 can comprise for example a motor cam rotation coupled switch 11102, including for example a cam/motor stop switch 7000 (see for example Figure 7B). Referring to Figure 11, in an exemplary implementation, a ratchet wheel rotation coupled switch 11002 can comprise a first conductive element 11810 (comprising for example and without limitation a spring and/or clip, etc., see for example Figures 8B and 9) connected to a drive ratchet encoder source pad 11814, and a second conductive element 11820 (comprising for example and without limitation a spring and/or clip, etc., see for example Figures 8B and 9) connected to a drive ratchet encoder ground pad 11822. Referring further to Figure 11, in an exemplary implementation, a motor cam rotation coupled switch 11102 can comprise a first conductive element 11710 (comprising for example and without limitation a spring and/or clip, etc., see for example Figure 7B) connected to a motor encoder source pad 11754, and a second conductive element 11720 (comprising for example and without limitation a spring and/or clip, etc., see for example Figure 7B) connected to a motor encoder ground pad 11752. [0060] Figure 12 illustrates in a block diagram an example of a configuration of design elements according to another exemplary implementations of example disclosed embodiments, where in an example non-limiting configuration, for example to facilitate reduced complexity and/or part count, a common (for example, coupled) ground pad 12502 and common conductive element 12501 may be used to, for example and without limitation, create a simplified, coupled mechanism. Referring to Figure 12, in an exemplary implementation, a ratchet wheel rotation coupled switch 11002 can comprise a first conductive element 11810 (comprising for example and without limitation a spring and/or clip, etc., see for example Figures 8B and 9) connected to a drive ratchet encoder source pad 11814, and a motor cam rotation coupled switch 11102 can comprise a first conductive element 11710 (comprising for example and without limitation a spring and/or clip, etc., see for example Figure 7B) connected to a motor encoder source pad

11754. Both the ratchet wheel rotation coupled switch 11002 and motor cam rotation coupled switch 11102 comprise, and/or are connected to, a common/coupled conductive element 12501

(comprising for example and without limitation a spring and/or a clip, etc.) connected to a common/coupled ground pad 12502.

[0061] Referring to a non-limiting illustration to Figure 13, according to an exemplary implementation of disclosed example embodiments, a cam/motor end stop switch can comprise a cam 13000 comprising a non-conductive body 13002 and a conductive portion 13004. In an exemplary implementation, body 13002 can be, or comprise, a plastic injection molded form.

In an exemplary implementation, conductive portion 13004 can be configured on, or formed as a part of, body 13002. For example, conductive portion 13004 comprise a conductive metal stamped part that can be pressed onto body 13002 during assembly of cam 13000. [0062] Referring to a non-limiting illustration to Figure 14, according to an exemplary implementation of disclosed example embodiments, a unitary conductive structure or a motor encoder conductive element 14002, such for example and without limitation a sheet metal comprising and or forming clips, springs, or a combination of both, can be used to transfer current from a source 7504 on a PCB 7002 to a cam/motor stop switch 14700 comprising for example a cam 7006. For example, compared to an example implementation illustrated in

Figures 7B-7D, source current 7500 will no longer travel through a clip 7022 / cam 7006 configuration, instead as illustrated in the example of Fi gure 14, source current 7500 travels from source 7504 via conductive element 14002, for example contact feature 14001, to cam

7006.

[0063] Figures 15A and 15B in non-limiting illustrations show an isometric three-dimensional views of various exemplary configuration of example components of a coupled motor/ratchet encoder switch 15000 according to exemplary implementations of disclosed example embodiments (see for example Figure 12). For example, combination 15000 comprises a ratchet 15800 including one or more conductors 15811 (see for example, configuration 8000 of

Figures 8A-8C), a cam 15700 including a conductive portion 15711 (see for example, configuration 7000 of Figures 7B-7D, 13, and 14), a driver ratchet encoder conductive element

15810 connected to a current source (for example on PCB 7002) and selectively connectable to conductors 15811 based on rotation of ratchet 15800, a common conductive element 15801 connected to ground and selectively connectable to conductors 15811 (based on rotation of ratchet 15800) and/or conductive portion 15711 (based on rotation of cam 15700), and a motor encoder conductive element 15710 connected to a current source (for example on PCB 7002) and selectively connectable to conductive portion 15711 based on rotation of cam 15700.

[0064] While the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the embodiments of the present disclosure. For example, operative variations and alternative different lead designs may be employed to change dosing resolution, encoders may be used to have feedback of drive mechanism, indexing drives can be employed to repeatably and fail-safe advance the plunger. Generally, for example, non-circular syringe barrel cross-sections may be employed to optimize space utilization and tailor device size to best suit user comfort.

Furthermore, any of the features or elements of any exemplary implementations of the embodiments of the present disclosure as describes above and illustrated in the drawing figures can be implemented individually or in any combination! s) as would be readily appreciated by skilled artisans without departing from the spirit and scope of the embodiments of the present disclosure.

[0065] In addition, the included drawing figures further describe non-limiting examples of implementations of certain exemplary embodiments of the present disclosure and aid in the description of technology associated therewith. Any specific or relative dimensions or measurements provided in the drawings other as noted above are exemplary and not intended to limit the scope or content of the inventive design or methodology as understood by artisans skilled in the relevant field of disclosure. The following non-limiting examples of operative variations or alternatives to the disclosed design embodiments are applicable and may further facilitate understanding of exemplary implementations of embodiments of the present disclosure.

[0066] For example and without limitation, each of the motion phases of the single-part dual cam driver may be reduced or extended to produce the desired ratchet mechanism motion. In alternate embodiments the dwell phases may be removed altogether if required. The cam surface minimum and maximum outer diameters may be adjusted to increase or decrease stroke length, and other motion curve types (such as sinusoidal, harmonic, or other variations) may be considered during the effective motion phase to change acceleration and actuation forces.

[0067] For example and without limitation, a similar central flange as described for the ratchet gear may be adapted to the single-part dual cam driver to better separate and guide the arms of the metal spring clip during mechanism actuation.

[0068] For example and without limitation, some or all of the stopper pins may be eliminated by adding protruding features to the formed baseplate. Elimination of pins m ay reduce part count and decrease costs to manufacture.

[0069] For example and without limitation, in place of the stopper pins, various electrical hardware components (such as an optical sensor, encoder, toggle lever, or push button) may be used to ensure the single-part dual cam driver rotates far enough to reset the mechanism before switching directions.

[0070] For example and without limitation, a wide range of materials may be used for some or all of the components used in the designed mechanism. [0071] For example and without limitation, the shape, size, and number of teeth on the ratchet gear may be changed to satisfy a wide variety of increment sizes.

[0072] For example and without limitation, proposed design of the single-part dual cam driver may be adapted to include three or more cam surfaces, all interfacing with their own clip arms or the arms of multiple clips.

[0073] Other objects, advantages and salient features of the disclosure will become apparent to those skilled in the art from the details provided, which, taken in conjunction with the annexed drawing figures, disclose exemplary embodiments of the disclosure.

Claims

Exemplary Non-Limiting Claims:

1. A ratchet cam combination comprising: a cam driver comprising a first cam surface and a second cam surface; a first arm configured to selectively contact the first cam surface; a second arm configured to selectively contact the second cam surface; and a ratchet comprising first gear teeth configured to contact the first arm and second gear teeth configured to contact the second arm, wherein, a rotation of the cam driver alternatingly causes: the first cam surface to push against the first arm to advance and push on a first engaged gear tooth of the first gear teeth, the second cam surfac e to retract from the second arm and pass over a second succeeding tooth of the second gear teeth; and the second cam surface to push against the second arm to advance and push on a second engaged gear tooth of the second gear teeth, the first cam surface to retract from the first arm and pass over a first succeeding tooth of the first gear teeth.

2. The combination of claim 1 , wherein the first cam surface and the second cam surface are symmetrically mirrored.

3. The combination of claim 1 or 2, further comprising a metal spring clip having the first arm and the second arm.

4. The combination of claim 1, 2, or 3 wherein the cam is a double tap cam

5. The combination of claim 1, 2, 3, or 4, wherein the ratchet is a double tap ratchet.

6. The combination of claim 1, 2, 3, 4, or 5, wherein the gear comprises the first gear teeth and the second gear teeth are axially aligned with each other and rotationally biased from each other.

7. The combination of claims 1, 2, 3, 4, 5, or 6, further comprising a cam switch configured with respect to the cam driver, the cam switch comprising: a conductive element selectively interfacing with an electrically conductive cam portion of the cam driver during the rotation of the cam driver.

8. The combination of claim 7, wherein the cam driver selectively interfaces with the conductive element connected to a current source or a ground via connection element, and the cam driver selectively interfaces with the other of the current source or the ground to selectively achieve a closed circuit.

9. The combination of claim 8, wherein the first arm and/or the second arm comprises an electrically conductive indexing portion connected to the current source or the ground, the conductive element is connected to the other of the current source or the ground, and the cam driver comprises the electrically conductive cam portion and an electrically non- conductive cam portion.

10. The combination of claim 9, wherein a current flow is selectively created between the electrically conductive indexing portion and the conductive element, when the electrically conductive cam portion contacts the connection element, and no current flow path is created when the electrically non-conductive cam portion contacts the connection element.

11. The combination of claim 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, further comprising a ratchet encoder comprising a first conductor connected to a ratchet encoder current source or a ratchet encoder ground and a second conductor connected to the other of the ratchet encoder current source and the ratchet encoder ground wherein the ratchet comprises one or more ratchet conductors selectively interfacing with the first conductor and the second conductor during the rotation of the ratchet.

12. The combination of claim 11, wherein the ratchet conductors comprise one or more pins or leads that path through the first gear teeth and the second gear teeth.

13. The combination of claim 11 or 12, wherein the first conductor conduction and/or the second conductor comprises a metal spring and/or a metal clip configured to selectively contact the ratchet.

14. The combination of claim 11, 12, or 13, wherein the ratchet comprises non-conductive ratchet portions, and as the ratchet rotates a short circuit is created when one of the ratchet conductors connects the first conductor to the second conductor an electrical short is created, and an open circuit is created when the first conductor and the second conductor connect to one of the non-conductive ratchet portions.

15. A system comprising the ratchet cam combination as claimed in claim 1, 2, 3, 4, 5, 6, 7, 8 9, 10, 11, 12, 13, or 14, the system further comprising: a motor operatively connected to a lead screw by the cam and the ratchet to rotate the lead screw; and a plunger disposed inside a barrel such that the plunger moves axially with respect to the barrel due to rotation of the lead screw, whereby fluid can be dispensed from the barrel by rotating the motor to drive the plunger to move axially with respect to the barrel, away from a proximal end and toward a distal end forcing the fluid out of the barrel.

16. The system of claim 15, wherein a portion of the lead screw operatively coupled to the ratchet cam combination is configured outside of the barrel to operatively connect the lead screw to the motor.

17. The system of claim 15 or 16, wherein the motor is a bi-directional motor.