Injectors and drive systems for auto-injectors with springless activation

Abstract

Injectors and drive modules for injectors are provided, for delivering an agent from an injector module including an agent chamber and a piston. The drive module includes a drive housing including a first chamber adjacent a first end communicating with a second chamber adjacent a second end thereof, an opening mechanism within the first chamber including an opener pin; a canister containing pressurized gas including an outlet adjacent the opener pin; an actuator configured to move the opening mechanism to cause the opener pin to open the outlet and release the gas to flow from the first chamber into the second chamber; and a plunger within the second chamber such that the gas causes the plunger to advance the piston to deliver the agent; wherein the actuator comprises a springless mechanism that moves one of the opening mechanism and the canister to cause the opener pin to open the outlet.

Description

INJECTORS AND DRIVE SYSTEMS FOR AUTO-INJECTORS WITH SPRINGLESS ACTIVATION RELATED APPLICATION DATA

[0001] The present application claims benefit of co-pending U.S. provisional application Serial No. 63 / 569,117, filed March 23, 2024, the entire disclosure of which is expressly incorporated by reference herein. The present application is related to U.S. Patent Nos. 10,716,892, 10,912,883, and 11,071,824, and U.S. Publication No. 2024 / 0033434, the entire disclosures of which are expressly incorporated by reference herein. TECHNICAL FIELD

[0002] The present application relates generally to devices and methods for delivering agents into a subject’s body and, more particularly, to injectors and / or gas- powered drive systems for injection devices, and to methods for making and using such devices. BACKGROUND

[0003] There are many applications involving delivery of a medicament or other agent subcutaneously, intramuscularly, or otherwise into a patient’s body. For example, auto-injectors are available that include a predetermined dose of the agent that may be delivered automatically into the patient’s body, e.g., after placement against the patient’s skin and activation. Generally, such auto-injectors are spring-loaded syringes that are activated to release the spring, which generates sufficient force to penetrate the skin with a needle and deliver the dose within the syringe. For viscous fluids, the forces required to develop fluid flow can be higher than those that spring-powered systems can provide. When springs can be used, they must generate a relatively high force that requires springs of high mass. Consequently, such auto-injectors may make substantial noise, create pressure spikes in the syringe leading to glass breakage, vibrate, and / or may drive the needle forcefully into the patient’s skin, which may cause pain and / or may startle the user, particularly when the patient is administering the injection themselves.

[0004] Therefore, improved devices and methods for delivering agents into a patient’s body would be useful.SUMMARY

[0005] The present application relates generally to devices and methods for delivering agents into a subject’s body and, more particularly, to injectors and / or gas- powered drive systems for injection devices, e.g., to actuators that may be included in such devices, and to methods for making and using such devices.

[0006] In accordance with one example, a drive module is provided for delivering one or more agents into a patient’s body from an injector module comprising an agent chamber containing one or more agents and a piston. The drive module includes a drive housing including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; an opening mechanism within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; an actuator configured to move one of the opening mechanism and the canister to cause the opener pin to open the outlet and cause the gas within the canister to flow from the first chamber into the second chamber; and a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, a distal end of the plunger configured to be coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber, wherein the actuator comprises a springless mechanism configured to move one of the opening mechanism and the canister to cause the opener pin to open the outlet.

[0007] In one example, the actuator comprises an actuator sleeve that is movable axially relative to the drive housing, and a linkage mechanism coupled to one of the opening mechanism and the canister, the actuator sleeve configured to cause the linkage to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet. For example, the actuator sleeve may be configured to slide axially over an exterior of the drive housing, and the linkage mechanism may include one or more arms that extend from the drive housing such that the actuator sleeve contacts the one or more arms to cause the linkage mechanism to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet.

[0008] In accordance with another example, an injector device is provided that includes an injector module comprising an agent chamber containing one or more agents and a piston. The device also includes a drive module including a drive housing including afirst end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; an opening mechanism within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; an actuator configured to move one of the opening mechanism and the canister to cause the opener pin to open the outlet and cause the gas within the canister to flow from the first chamber into the second chamber; and a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, a distal end of the plunger coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber, wherein the actuator comprises a springless mechanism configured to move one of the opening mechanism and the canister to cause the opener pin to open the outlet.

[0009] The devices herein may include any of the actuators disclosed in the patents incorporated by reference herein. For example, an actuator sleeve may be provided that is retracted when a needle of the device is inserted into a patient’s skin, thereby actuating a linkage mechanism to move the opening mechanism to release the gas.

[0010] In accordance with still another example, a drive module is provided for delivering one or more agents into a patient’s body from an injector module comprising an agent chamber containing one or more agents and a piston, the drive module including a drive housing including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; a pin mount within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, the plunger configured to be coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber; an actuator sleeve adjacent the drive housing configured to be operatively coupled to an actuator to direct the actuator sleeve axially in a first direction relative to the drive housing; and a linkage mechanism coupled to one of the pin mount and the canister, the actuator sleeve configured to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

[0011] In accordance with yet another example, an injector device is provided that includes an injector module including an agent chamber containing one or more agents and a piston, and an activation cap. The injector device also includes a drive module including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; a pin mount within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, the plunger configured to be coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber; an actuator sleeve adjacent the drive housing operatively coupled to the actuator to direct the actuator sleeve axially in a first direction relative to the drive housing; and a linkage mechanism coupled to one of the pin mount and the canister, the actuator sleeve configured to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

[0012] In accordance with still another example, an injector device is provided that includes an injector module including an agent chamber containing one or more agents and a piston, and an activation cap. The injector device also includes a drive module including a drive housing including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; a pin mount within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, the plunger configured to be coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber; an actuator sleeve adjacent the drive housing operatively coupled to the actuator to direct the actuator sleeve axially in a first direction relative to the drive housing; and a linkage mechanism coupled to one of the pin mount and the canister, the actuator sleeve configured to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

[0013] Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] It is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:

[0015] FIG. 1 is a perspective view of an exemplary auto-injector device including a front and rear housing, and a safety cap.

[0016] FIGS. 2A and 2B are longitudinal cross-sections of an exemplary auto- injector device showing internal components of the device including a syringe carrying one or more agents.

[0017] FIGS. 3A and 3B are details of the distal end of the device of FIGS. 2A and 2B before use, showing a safety cap covering an activation cap and needle of the device.

[0018] FIGS. 4A-4C are cross-sections of the device of FIGS. 2A and 2B, showing activation of the device when the activation cap is displaced proximally when the device is pressed against a subject’s skin to puncture the skin with the needle, the activation cap causing a spacer and release cap to also displace proximally to release a carriage carrying an opener pin, causing the opener pin to advance distally to open a gas canister to release pressurized gas into a flow path within the device.

[0019] FIGS. 5A-5C are details of the proximal end of the device as shown in FIGS. 4A-4C, respectively.

[0020] FIGS. 6A and 6B are cross-sections of the device of FIGS. 2A and 2B after the pressurized gas is released, showing the pressurized gas advancing a plunger within the device to deliver one or more agents within the syringe through the needle, and advancing the activation cap when the needle is withdrawn from the subject’s skin.

[0021] FIG. 6C is a detail of the device as shown in FIG. 6B, showing a tab locking the activation cap after being advanced.

[0022] FIG. 7 is a schematic showing an example of an actuator that may be included in an injector device for opening an outlet of a gas canister.

[0023] FIGS. 8A and 8B show the actuator of FIG. 7 before and after activation, respectively.

[0024] FIGS. 9A and 9B show another example of an actuator that may be included in an injector device for opening an outlet of a gas canister, shown before and after activation, respectively.

[0025] The drawings are not intended to be limiting in any way, and it is contemplated that various examples of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown. DETAILED DESCRIPTION

[0026] Before the examples are described, it is to be understood that the invention is not limited to particular examples described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular examples only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

[0027] Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

[0028] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, some potential and exemplary methods and materials are now described.

[0029] It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a compound” includes a plurality of suchcompounds and reference to “the polymer” includes reference to one or more polymers and equivalents thereof known to those skilled in the art, and so forth.

[0030] Certain ranges are presented herein with numerical values being preceded by the term “about.” The term “about” is used herein to provide literal support for the exact number that it precedes, as well as a number that is near to or approximately the number that the term precedes. In determining whether a number is near to or approximately a specifically recited number, the near or approximating unrecited number may be a number which, in the context in which it is presented, provides the substantial equivalent of the specifically recited number.

[0031] Turning to the drawings, FIG. 1 shows an example of an auto-injector device 6 that includes an outer housing 8 including a front housing 10 carrying a syringe 70 containing one or more agents within an agent chamber, and a rear housing 12 including a drive assembly for automatically delivering the agent(s) from the syringe 70 when the device 6 is activated. As shown, a safety cap 86 is provided on the front housing 10 to prevent premature activation of the device 6, which may be removed immediately before an injection, as described further elsewhere herein. One or more internal components of the device 6 may move axially, i.e., proximally and / or distally relative to the longitudinal axis 18 when the device 6 is activated, as described further elsewhere herein.

[0032] In one example, the syringe 70 may be a pre-filled syringe, e.g., formed from glass, plastic, and the like, filled with a predetermined volume of agent, e.g., corresponding to a single dose for a patient. Alternatively, the agent chamber and needle may be integrated into the front housing 10 if desired (not shown). In a further alternative, the syringe 70 (or integral agent chamber) may include a distal port (not shown) without a needle, such that a separate needle (also not shown) may be coupled to the port, e.g., using a Luer fitting, mating threads, and / or other cooperating connectors, immediately before an injection or otherwise as desired. As used herein, “agent” may include one or more flowable therapeutic and / or diagnostic compounds, medicaments, or materials, e.g., in liquid or gaseous form, in solution or suspension, and the like, such as viscous fluids.

[0033] Turning to FIGS 2A and 2B, an exemplary auto-injector device 6 is shown that includes an outer housing 8 including a front housing 10 carrying a syringe 70 containing one or more agents within an agent chamber 73, and a rear housing 12 including a drive assembly for automatically delivering the agent(s) from the syringe 70 when the device 6 is activated. As shown, a safety cap 86 is provided on the front housing 10 toprevent premature activation of the device 6, which may be removed immediately before an injection, as described further elsewhere herein. One or more internal components of the device 6 may move axially, i.e., proximally and / or distally relative to the longitudinal axis 18 when the device 6 is activated, as described further elsewhere herein.

[0034] In one example, the syringe 70 may be a pre-filled syringe, e.g., formed from glass, plastic, and the like, filled with a predetermined volume of agent, e.g., corresponding to a single dose for a patient. Alternatively, the agent chamber and needle may be integrated into the front housing 10 if desired (not shown). In a further alternative, the syringe 70 (or integral agent chamber) may include a distal port (not shown) without a needle, such that a separate needle (also not shown) may be coupled to the port, e.g., using a Luer fitting, mating threads, and / or other cooperating connectors, immediately before an injection or otherwise as desired. As used herein, “agent” may include one or more flowable therapeutic and / or diagnostic compounds, medicaments, or materials, e.g., in liquid or gaseous form, in solution or suspension, and the like, such as viscous fluids.

[0035] With continued reference to FIGS. 2A and 2B, the syringe 70 includes a barrel 72 containing the agent(s) within agent chamber 73, a needle 78 extending from a distal end 72a of the barrel 72, and a piston or stopper 74 slidable within a proximal end 72b of the barrel 72 for directing the agent(s) through the needle 78 into the subject’s body (not shown). The device 6 also includes a gas canister or other source of pressurized gas 40 to power the device 6, e.g., to advance a plunger 50 coupled to the piston 74 to deliver the agent(s). The device 6 also includes an activation cap 80 and an opening mechanism 60 for opening the canister 40 to release pressurized gas within the canister 40 into a set of chambers of the device 6. For example, an inner housing 20 may be mounted within the outer housing 8 that includes a first or proximal chamber 22, e.g., within which the gas canister 40 is mounted, and a second or distal chamber 24, e.g., in which the plunger 50 is slidably received.

[0036] Generally, the device 6 is configured such that, when a contact surface 84 of the activation cap 80 is pressed against a subject’s skin to insert the needle 78, the activation cap 80 retracts proximally into the outer housing 8 and automatically activates the opening mechanism 60 to release the pressurized gas from the canister 40 into the first and second chambers 22, 24, which generates a distal force to advance the plunger 50 to deliver the agent(s) from the syringe 70 into the subject. After the injection is completed and thedevice 6 is withdrawn away from the skin, the activation cap 80 may automatically advance to cover the needle 78.

[0037] For example, a spacer 30 may be provided that extends between the activation cap 80 and a release cap 34 of the opening mechanism 60, e.g., such that proximal movement of the activation cap 80 is translated by the spacer 30 to the direct the release cap 34 proximally within the rear housing 12, which releases a spring perch assembly or carriage 64 of the opening mechanism 60, as described further elsewhere herein. The spacer 30 may be biased distally, e.g., by spring 32, which may, in turn, bias the activation cap 80 distally after completing the injection, also as described further elsewhere herein.

[0038] Generally, the outer housing 8 includes a proximal end 8a, e.g., provided on the rear housing 12, an open distal end 8b, e.g., provided on the front housing 10, and an inner wall extending therebetween to enclose the interior of the device 6. The outer surface between the proximal and distal ends 8a, 8b may be sized and / or shaped to facilitate manipulation of the device 6, e.g., to facilitate placing and pressing the activation cap 80 against a subject’s skin to activate the device 6 and inject the agent(s). For example, the outer surface may have a generally cylindrical shape optionally including one or more textures or grip features to facilitate an operator (the subject themselves or a third party) holding the device 6 in one hand and pressing the activation cap 80 against the subject’s skin, as described further elsewhere herein. As shown, the proximal end 8a of the housing 8 may include a wall 8c enclosing the proximal end 8a and, optionally, one or more pockets or other features 8d for locking the release cap 34, as described further elsewhere herein.

[0039] The outer housing 8 may be formed from multiple, separate components, e.g., clamshell halves, e.g., formed from metal, such as stainless steel, aluminum, and the like, plastic, and / or composite material, by one or more of cold drawing, molding, casting, machining, and the like, that are substantially permanently attached together, e.g., by one or more of welding, soldering, fusing, bonding with adhesive, interference fit, and the like. As shown, the outer housing 8 is formed as separate forward and rear housings 10, 12, which may be assembled separately with respective internal components, and then coupled together, e.g., after loading a syringe 70 into the front housing 10.

[0040] For example, during manufacturing, the front housing 10 may be assembled with the activation cap 80 and safety cap 86, and a syringe 70 may be loaded into an interior of the front housing 10, e.g., during manufacturing or during assembly of the device 6 anytime before performing an injection. Optionally, as shown in FIGS. 3A and 3B, the syringe 70 may include a rigid needle shield 79, e.g. formed from conventional materials, that may be removably secured to the distal end 72a of the barrel 72 to protect the needle and prevent accidental sticks. The safety cap 86 may include features 86a that engage the needle shield 79 such that, when the safety cap 86 is removed, the needle shield 79 is also removed. For example, as shown, the proximal end of the safety cap 86 may include one or more fingers 86a that fit into one or more corresponding cutouts, recesses, or other features on the needle shield 79 when the syringe 70 is inserted into the front housing 10, thereby coupling the needle shield 79 to the safety cap 86, as described elsewhere herein.

[0041] The rear housing 12 may be assembled with the inner housing 20, the spacer 30, the release cap 34, the gas canister 40, the plunger 50, and the opening mechanism 60 (and any other incidental components), and the rear housing 12 may be coupled to the front housing 10 at any time. For example, during manufacturing, a syringe 70 may be loaded into the interior of the front housing 10, and the assembled rear housing 12 may be immediately coupled to the front housing 10. When the rear housing 12 is attached to the front housing 10, a distal end 54 of the plunger 50 may be coupled to the piston 74 within the syringe 70, e.g., such that distal movement of the plunger 50 is translated to the piston 74, as described further elsewhere herein.

[0042] As shown in FIGS. 2A and 2B, the outer housing 8 may include a mount 11, e.g., on one of the forward and rear housings 10, 12, for guiding and / or securing the syringe 70 during loading. Optionally, the proximal end 72b of the barrel 72 may include one or more flanges, e.g., a radial flange or a pair of opposing flanges, that may abut and / or be received within the mount 11 to secure the syringe 70 relative to the front housing 10. In addition or alternatively, one or more detents, ridges, or other features (not shown) may be provided on the front housing 10 for securing the syringe 70. Optionally, the front housing 10 may include one or more windows 10c in the sidewall, which may facilitate observing the syringe 70 during an injection, e.g., to allow visual confirmation when the piston 74 is fully advanced.

[0043] Optionally, the device 6 may include a syringe spacer or adapter 75 that may provide an interface between a distal end 54 of the plunger 50 and the piston 74, e.g., to provide connectors therebetween and / or ensure proper spacing such that the piston 74 is advanced in conjunction with the plunger 50. For example, different length spacers 75 may be provided to allow different length syringes to be loaded into the front housing 10 whileproperly positioning the needle 78 adjacent the distal end 8b of the outer housing 8 and allowing the plunger 50 to be properly coupled to the piston 74.

[0044] During manufacturing or assembly, a syringe 70 may be selected that may be inserted into the housing 8, e.g., through the opening in the distal end 8b and coupled to the distal end 16 of the drive assembly 12. A syringe spacer 75 may be selected and its distal end 75a may be coupled to the piston 74, e.g., by one or more cooperating threads, as shown, one or more detents or other connectors, and the like. The distal end 54 of the plunger 50 may be inserted into a recess 75b in the syringe spacer 75 when the rear housing 12 is coupled to the front housing 10. Optionally, the distal end 54 of the plunger 50 and the recess 75b may include cooperating locking features, e.g., one or more threads, detents, and the like (not shown) or the distal end 54 may simply be inserted into the recess 75b to coupled subsequent distal movement of the piston 74 to the plunger 50, as described further elsewhere herein.

[0045] Alternatively, the assembled housings 10, 12 may be packaged, stored, and / or otherwise prepared for subsequent assembly. For example, the housing 10, 12 may be shipped or otherwise provided to a manufacturer of the syringe 70, who may load the syringe 70 and couple the housings 10, 12 together to provide the finished device 6. In a further alternative, the assembled housings 10, 12 may be provided to a hospital, physician, or other medical professional, and final assembly may be completed immediately before performing an injection, which may allow a syringe including a specific agent to be loaded before an injection.

[0046] The proximal end 10a of the front housing 10 and the distal end 12b of the rear housing 12 may include one or more cooperating connectors (not shown) to couple the housings 10, 12 together to provide the fully-assembled device 6. For example, the housings 10, 12 may include one or mating threads, detents, and the like, which may permanently couple the housings 10, 12 together. Alternatively, the connectors may allow the housings 10, 12 to be subsequently separated, e.g., after performing an injection, to remove the syringe 70, e.g., to allow the device 6 to be cleaned and reused with a new syringe.

[0047] In addition or alternatively, the housings 10, 12 may be permanently attached together by one or more of an interference fit between the ends 10a, 12b, bonding with adhesive, fusing, sonic welding, and the like. In another alternative, the outer housing 8 may be formed as a single, integral component into which the components of the device 6may be assembled. In these alternatives or even with a two-part housing, the device 6 may be a single use device, which may be disposed of after a single injection.

[0048] In the example shown in FIGS. 2A and 2B, the inner housing 20 includes a proximal cylinder 20a including the first chamber 22 and a distal cylinder 20b including the second chamber 24. Each of the proximal and distal cylinders 20a, 20b may have an elongate cylindrical wall or other cross-sectional shape along their lengths. The proximal and distal cylinders 20a, 20b may be permanently attached together to provide the inner housing 20, e.g., by one or more of cooperating threads, as shown, detents or other connectors, force fit, bonding with adhesive, sonic welding, fusing, and the like. Alternatively, the inner housing 20 may be formed as a single, unitary structure including the first and second chambers 22, 24. The proximal and distal cylinders 20a, 20b may be formed from materials similar to or different from the outer housing 8.

[0049] The inner housing 20 may be mounted within the outer housing 8 such the inner housing 20 remains substantially stationary within the outer housing 8. Similarly, the gas canister 40 may be mounted within the inner housing 20, e.g., within the first chamber 22, such that the gas canister 40 also remains substantially stationary relative to the outer housing 8. For example, one or more struts, supports, or other structures (not shown) may be provided on the inner and / or outer housings 20, 8 to secure the inner housing 20 and / or the gas canister 40 relative to the outer housing 8.

[0050] In the example shown, the proximal cylinder 20a may include an annular wall surrounding the first chamber 22 that includes a uniform diameter first region 22a within which the gas canister 40 is mounted, and second and third regions 22b, 22c within which the carriage 64 is slidably mounted, as described further elsewhere herein. The distal cylinder 20b may have a length such that a distal end 21b of the distal cylinder 20b may abut the syringe 70 when the device 6 is assembled.

[0051] Optionally, the distal end 21b may include one or more features that contact the proximal end 72b of the syringe 70, e.g., an O-ring 20d secured on or around the distal end 21b formed from resilient and / or relatively flexible material. The O-ring 20d may prevent the distal end 21b from damaging the syringe 70, e.g., if the barrel 72 is made from glass.

[0052] With continued reference to FIGS. 2A and 2B, the canister 40 includes a body 42 including a first closed end 42a, a second outlet end 42b, and a cap 44 welded or otherwise attached to the outlet end 42b to provide an enclosed cavity 48 filled with a fluidcontaining pressurized gas, such as carbon dioxide or fluorocarbon gases, compressed to sufficient pressure to least partially liquefy the gas within the cavity 48. Alternatively, fluids containing gases such as argon, nitrogen, helium, or other combinations thereof that remain in gaseous form may be stored within the cavity 48. As described elsewhere herein, the pressurized fluid contained within the cavity 48 may be used to generate the forces to operate the device 6, e.g., to inject one or more agents from the syringe 70 into a subject’s body.

[0053] In one example, the body 42 and cap 44 may be formed from stainless steel or other desired or suitable metal, plastic, or composite material, e.g., formed by one or more of drawing, stamping, machining, casting, molding, and the like. For example, the body 42 may be deep drawn from sheet metal, e.g., a round sheet metal blank of Type 305 stainless steel, using one or more dies and punches (not shown), to form a main barrel region, the enclosed end 42a, an optional tapered shoulder region, and the outlet end 42b defining an opening to which the cap 44 is attached.

[0054] As shown, the canister 40 may be oriented with the outlet end 42b proximal to the enclosed end 42a, and the carriage 64 may be provided proximal to the outlet end 44. In the example shown, the cap 44 may be an enclosed cap including an outlet, weakened region, or other outlet (not shown) that may be opened by the opening mechanism. In this example, the carriage 64 may include an opener pin 62 configured to puncture or preferentially tear the septum, as described elsewhere herein. Additional information regarding canisters that may be used and methods for making them may be found in U.S. Publication No. 2017 / 0258583, the entire disclosure of which is expressly incorporated by reference herein.

[0055] Alternatively, the cap 44 may include other closer mechanisms, such as a ball or other member (not shown) that may be biased or otherwise configured to close an outlet in the cap 44 yet may be directed away from the cap 44, e.g., into the canister 40, by the carriage 64 to open the outlet and release the pressurized gas within the cavity 48. In this alternative, the opener pin 62 may include a tapered tip (not shown) sized to enter the outlet and push the closure away from the outlet.

[0056] The plunger 50 may be an elongate rod or other member including a proximal end 52 that is slidably disposed within the second chamber 24, e.g., initially immediately adjacent the first chamber 22, and a distal end 54 coupled to the piston 74. The plunger 50 is movable from an initial or retracted position (e.g., shown in FIGS. 2A and 2B)to a final or extended position (e.g., shown in FIGS. 6A and 6B), e.g., wherein the distal end 54 extends from the second end 16 of the drive assembly 12 into the agent chamber 73 of the syringe 70.

[0057] A flange or other guide member 53 may be provided on the proximal end 52 of the plunger 50 that slidably engages a wall of the second chamber 24. Consequently, when pressurized gas enters the second chamber 24 (via the first chamber 22), the pressure generates a distal force to direct the plunger 50 distally from the initial position towards the extended position to advance the piston 74 and deliver the one or more agents from the agent chamber 73 through the needle 78 into the subject, as described further elsewhere herein.

[0058] Optionally, a wall, orifice, or intermediate passage (not shown) may be provided between the first and second chambers 22, 24. The intermediate passage may have a relatively small diameter to provide a restrictor to reduce pressure rise time within the second chamber 24. For example, the intermediate passage may i) slow down the transient flow of gas, slowing the rise of pressure imparted to the plunger 50, e.g., providing a soft-start to the injection, reducing / eliminating pressure shock waves in the fluid to be injected in the syringe and possibly reducing patient pain as the drug injection is gently initiated; and / or ii) slow down the steady state flow of gas, reducing the otherwise pressure imparted to the plunger 50, providing a limiting effect to the flow rate of the drug injected into the patient.

[0059] Optionally, as shown, the plunger 50 may also include a plunger chamber 56, e.g., extending from an open proximal end 52 of the plunger 50 to a closed distal end 54. The plunger chamber 56 may taper inwardly from the proximal end 52 to the distal end 54, as shown, or may have a uniform diameter or other cross-sectional shape along its length. Alternatively, the proximal end 52 of the plunger 50 may include a closed wall and / or the plunger 50 may be a solid rod between the proximal and distal ends 52, 54.

[0060] Optionally, the flange 53 on the proximal end 52 of the plunger 50 may include one or more passages (not shown) that extend between proximal and distal surfaces of the flange 53. For example, the flange 53 may include a plurality of circular or other enclosed passages spaced apart from one another around a circumference of the flange 53, each extending between the proximal and distal surfaces.

[0061] In this option, the flange 53 may be sized and / or shaped to slidably engage an inner wall of the second chamber 24, e.g., to allow the plunger 50 to move from theinitial to the extended position, but may not require O-rings or other seals. Instead, one or more O-rings or other seals may be provided within and / or adjacent the inner housing 20 to seal the first and second chambers 22, 24 and / or otherwise a flow path from the gas canister 40 to the plunger 50. For example, a first O-ring 58a may be provided between the inner housing 20 and the carriage 64, a second O-ring 58b may be provided between a distal end 21b of the inner housing 20 and the plunger 50, and / or a third O-ring 58c may be provided between the proximal and distal cylinders 10a, 10b, if provided as separate components secured together.

[0062] In one example, the plunger 50 includes a flange 53 formed as a cylindrical head having a larger outer diameter than the plunger 50, which may be integrally molded or otherwise formed with the plunger 50, or that is manufactured separately and permanently attached to the plunger 50, with one or more passages (not shown) extending between the proximal and distal surfaces of the flange 53. When the canister 40 is opened to release the pressurized gas, the initial volume that the gas must fill the first chamber 22 around the canister 40, the second chamber 24 around the plunger 50 and, optionally, the plunger chamber 56, which may result in an initial pressure drop as the gas fills the available volume. However, as the plunger 50 advances, the change in volume that the gas must fill increases only minimally (e.g., the volume the plunger 50 occupies within the second chamber 24 that is displaced out of the distal end 16 of drive assembly 12). Consequently, because the volume change is minimized, the resulting force applied by the pressure on the plunger 50 may remain substantially constant or reduce only slightly. Thus, the resulting force drop applied to the plunger 50 may be minimized, which may provide a more uniform delivery rate of the agent from the syringe 70. Additional information regarding plungers that may provide reduced pressure drop can be found in co-pending U.S. application, Serial Nos. 17 / 965,707, the entire disclosure of which is expressly incorporated by reference herein.

[0063] Optionally, the proximal end 52 of the plunger 50 may have a larger diameter or other cross-section than the distal end 54 of the plunger 50. For example, the outer diameter or cross-section may taper between the proximal and distal ends 52, 54 of the plunger 50. Such a tapered shape may increase the cross-sectional area of the plunger 50 as it advances from the initial position towards the extended position, which may minimize the change in the distal force applied to the syringe stopper due to volume change, which may be particularly useful for applications where consistent rates of delivery are desired. It willbe appreciated that any of these optional features related to the plunger 50 may be combined together or omitted, as desired.

[0064] Returning to FIGS. 2A and 2B, the opening mechanism 60 includes a release cap 34 and a spring perch assembly or carriage 64 slidably coupled to the rear housing 12, e.g., within the second and third regions 22b, 22c of the first chamber 24. The carriage 64 carries the opener pin 62, e.g., mounted along the axis 18 and oriented distally towards the cap 44. The carriage 64 and release cap 34 include one or more features that disengage when the release cap 34 is directed proximally (by the activation cap 80 and spacer 30), and the carriage 64 may be biased to move distally, when released, to direct the opener pin distally to open the outlet in the cap 44 of the canister 40.

[0065] For example, the rear housing 12 and the carriage 64 may include cooperating features that prevent the carriage 64 from moving until the device 6 is activated. For example, as best seen in FIGS. 5A-5C, the carriage 64 includes locking tabs or other features 64a on its proximal end that engage the proximal end 13a of the rear housing 12, and a flange 64b on its distal end slidable within the second region 22b of the first chamber 24. A puncture spring 66 is also provided within the second region 22b around the carriage 64, e.g., a coil spring provided in an initially compressed state between the rear housing 12 and the flange 64b. Consequently, the spring 66 biases the carriage 64 to move distally, but for the locking features 64a engaging the proximal end 13a of the rear housing 12.

[0066] The release cap 34 and carriage 64 include cooperating features that release the locking features 64a from the rear housing 12 when the device 6 is activated. For example, as shown in FIGS. 5A-5C, the release cap 34 includes a cylindrical body surrounding a portion of the rear housing 12, e.g., around the second and third regions 22b, 22c of the first chamber 24. The release cap 34 may also include an enclosed proximal end 34a proximal to the proximal end 13a of the rear housing 12, and a distal end 34b that includes one or more features to limit axial movement of the release cap 34. For example, one or more flanges on the distal end 34b may slide proximally along the inner surface of the outer housing 8, e.g., until they abut a ridge on the outer housing 8 to prevent further proximal movement of the release cap 34, as described further elsewhere herein.

[0067] As shown, a central hub 36 is provided on the proximal end 34a of the release cap 34 aligned along the axis 18 distally towards the opener pin 62. The carriage 64 includes a plurality of tabs or release fingers 65, e.g., arranged concentrically around the axis 18 such that the tabs 65 may slide along the hub 36 as the release cap 34 is directedproximally. Once the hub 36 moves proximally beyond the tabs 65, the tabs 65 are biased to move radially inwardly (towards the central axis 18), thereby directing the locking features 64a inwardly. Once the locking features 64a clear the proximal end 13a of the rear housing 12, e.g., as shown in FIG. 5C, the spring 66 may automatically direct the carriage 64 distally, thereby directing the opener pin 62 distally to penetrate the septum in the cap 44 of the canister 40 (or otherwise opening the outlet).

[0068] During use, the device 6 may be provided initially with the safety cap 86 attached to the distal end 8b of the housing 8, e.g., as shown in FIGS. 1-2B. Immediately before performing an injection, the safety cap 86 may be removed, e.g., by simply pulling the safety cap 86 distally away from the outer housing 8, to expose the contact surface 84 of activation cap 80, e.g., as shown in FIG. 4A. For example, as best seen in FIGS. 3A and 3B, the safety cap 86 may include inner and outer cylindrical members with the proximal end 86a of the inner member coupled to the needle shield 79 and a proximal end 86b of the outer member slidably received over the distal end 8b of the outer housing 8. Alternatively, the safety cap 86 and / or outer housing 8 may include one or more connectors, locks, and the like (not shown) that may be disengaged before removing the safety cap 86.

[0069] As described elsewhere herein, the safety cap 86 may prevent the activation cap 80 from being directed proximally, e.g., by preventing the activation cap 80 from being contacted. In addition or alternatively, the safety cap 86 may include features that engage the needle shield 79 such that, when the safety cap 86 is removed, the needle shield 79 is also removed. The safety cap 86 and needle shield 79 may prevent the needle 78 from being exposed from the housing 8 prior to use. Once the safety cap 86 and needle shield 79 are removed, the device 6 is ready to be used to perform an injection.

[0070] Turning to FIGS. 4A-4C, the contact surface 84 may be placed against a subject’s skin (not shown) and then the device 6 may be pressed against the skin to insert the needle 78, thereby causing the activation cap 80 to slide proximally from the initial position shown in FIG. 4A to the retracted position shown in FIG. 4B as the needle 78 enters the subject’s skin. As described further below, this action may activate the opening mechanism 60 to cause the opener pin 62 to open the outlet of the gas canister 40 to release pressurized gas into the first chamber 22, whereupon the pressurized gas may advance the plunger 50 and, consequently, the piston 74 to deliver the agent(s) through the needle 78 into the subject.

[0071] For example, as shown in FIG. 4A, initially, the proximal end 82 of the activation cap 80 may abut or otherwise engage a distal end 30a of the spacer 30, and a proximal end 30b of the spacer 30 may abut or otherwise engage the distal end 34b of the release cap 34. Consequently, when the activation cap 80 is retracted proximally within the outer housing 8, its proximal end 82 pushes the distal end 30a of the spacer 30, thereby directing the spacer 30 proximally, and, in turn, the proximal end 30b of the spacer 30 pushes the distal end 34b of the release cap 34, thereby directing the release cap 34 proximally, e.g., until the proximal end 34a of the release cap 34 contacts the proximal end 8c of the outer housing 8.

[0072] As the activation cap 80, spacer 30, and release cap 34 move proximally, the inner housing 20 (and canister 40 within the first chamber 22) may remain substantially stationary. As can be seen in FIGS.4A and 4B, as the spacer 30 is directed proximally, the spring 32 may be compressed, e.g., between features on the distal end 30a of the spacer 30 and the inner housing 20, thereby biasing the spacer 30 subsequently to move distally. However, with the operator pressing the contact surface 84 of the activation cap 80 against the subject’s skin, the spacer 30 is unable to move distally.

[0073] Since the carriage 64 is secured relative to the inner housing 20 by the locking features 64a, the carriage 64 also remains substantially stationary, such that the release cap 34 moves proximally relative to the carriage 64 and the tabs 65 on the carriage 64 slide along the hub 36 on the release cap 34, as best seen in FIGS. 5A-5C. When the release cap 34 reaches its proximal-most position, e.g., shown in FIGS. 4C and 5C, the hub 36 has moved proximally beyond the ends of the tabs 65 and, given the inward bias of the tabs 65, the tabs 65 are released and automatically move inwardly. Given that the tabs 65 are coupled to the locking features 64a on the carriage 64, the inward movement of the tabs 65 causes the locking features 64a to move inwardly, thereby disengaging the locking features 64a from the proximal end 21a of the inner housing 20.

[0074] Due to the spring 66, the carriage 64 is then released and biased to move distally, thereby advancing the opener pin 62 distally to open the outlet of the canister 40, as shown in FIGS. 4C and 5C. The release cap 34 may include one or more tabs or other features 34c, e.g., corresponding to the pockets 8d in the outer housing 8, such that, when the release cap 34 reaches its proximal-most position, the tabs 34c are received in respective pockets 8d, as shown. Thus, the tabs 34c may prevent the release cap 34 from moving distally as the carriage 64 advances distally due to the spring 66.

[0075] When the carriage 64 moves distally, it causes the opener pin 62 to advance and penetrate the septum in the cap 44 (or otherwise open the outlet), thereby releasing the pressurized gas within the canister 40. The released pressurized gas then enters the first chamber 22, e.g., around the canister 40, and passes to the second chamber 24, thereby pressurizing the second chamber 24 to generate a distal force to direct the plunger 50 distally from the initial position towards its extended position to deliver the one or more agents from the syringe 70 through the needle 78 into the subject, e.g., as shown in FIG. 6A.

[0076] The operator may monitor the syringe 70 during the injection, e.g., via the window(s) 8c to confirm that the piston 74 has fully advanced distally within the barrel 72 to deliver the entire dose into the subject. Once the injection is completed, the device 6 may be directed away from the subject, thereby withdrawing the needle 78 from the subject’s skin. As the device 6 is directed away from the subject’s skin, the activation cap 80 is free to move distally and, due to the distal bias of the spring 32, the spacer 30 automatically advances distally, thereby directing the activation cap 80 distally to cover the needle 78 as it is withdrawn.

[0077] As best seen in FIG. 6C, as the spacer 30 advances distally, the proximal end 30b of the spacer may pass distally beyond features 34d on the distal end 34b of the release cap 34. For example, the features 34b may include one or more fingers or tabs that slide along the interior of the spacer 30 until the proximal end 30b passes distally, whereupon the tabs may resiliently move radially outwardly, e.g., such that the tabs 34d are located proximal to the proximal end 30b of the spacer 30, thereby preventing the spacer 30 from subsequently moving proximally. With the spacer 30 prevented from moving proximally, the activation cap 80 is unable to retract again, thereby locking the activation cap 80 extended over the needle 78 and preventing accidental exposure of the needle 78.

[0078] If the device 6 is a single-use device, the device 6 may then be disposed of. If the device is reusable, e.g., if the forward and rear housings 10, 12 are separable, the rear housing 12 may subsequently be separated from the front housing 10, and the syringe 70 may be removed. For a reusable device, one or more features may be provided within the device to release any residual pressure within the first and second chambers 22, 24. For example, as shown in FIGS. 6A and 6B, a gas valve and / or shaft member may be provided within the plunger 50, which may be manipulated to release the pressurized gas before removing decoupling the plunger 50 from the piston 74. The separate housings 10, 12 maythen be cleaned and / or sterilized and a new gas canister 40 may be loaded into the inner housing 20 before reassembling the device.

[0079] Turning to FIG. 7, an example of an actuator 112 is shown that may be included in an injector device, e.g., in place of internal components of the drive module of the device 6 shown in FIGS. 1-6. For example, the actuator 112 may replace the opening mechanism 60 (e.g., including at least the release cap 34 and carriage 64) to provide an actuator that does not rely on springs to open an outlet of a gas canister that is used to power the injector device, but rather uses a mechanical linkage that opens the outlet.

[0080] As with the device 6, the actuator 112 includes a gas canister 40 mounted within an inner housing 120, which may be similar to the drive housing 20 of the device 6, e.g., including a first chamber 122 within which the canister 40 is mounted such that the canister 40 is axially fixed within the inner housing 120. The inner housing 120 may include a second chamber within which a plunger (not shown) is slidably disposed such that, when pressurized gas is released from the canister 40, the gas may pass from the first chamber 122 into the second chamber, thereby advancing the plunger, e.g., to advance a piston of an injector module (also not shown), e.g., similar to the syringe 70 of the device 6.

[0081] The actuator 112 also includes a linkage mechanism 160 that carries a pin mount or block168 carrying an opener pin 162, which may be initially spaced apart from an outlet 44a (e.g., within a cap 44 of the canister), e.g., as shown in FIG. 8A. The pin mount 168 may be movable axially, e.g., to direct the opener pin 162 to open the outlet 44a, e.g., as shown in FIG. 8B. The linkage mechanism 160 includes a pair of arms 166 that extend from the pin mount 168 diagonally outwardly through the inner housing 120, e.g., through corresponding slots or openings (not shown) that accommodate movement of the arms 166. For example, each arm 166 may include a first or inner end 166a pivotally coupled to the pin mount 168 (e.g., by a hinge) and a second or outer end 166b that is disposed outside and adjacent the housing 120.

[0082] The linkage mechanism 160 also includes linkage arms or elements 169 coupled between the arms 166 and a stationary mount 121, which is axially fixed relative to the housing 120. For example, each arm 166 may include a linkage element 169 pivotally coupled at a location between the first and second ends 166a, 166b and pivotally coupled to the stationary mount 121. Consequently, if the second end 166b of each arm 166 is moved in a first axial direction (e.g., pivoted to the left in FIGS. 7-8B) relative to longitudinal axis118, the pin mount 168 may move in a second, opposite axial direction (e.g., to the right in FIGS. 7-8B).

[0083] In one example, the canister 40 may mounted within an injector device with the outlet 44a oriented proximally, i.e., away from an injector module of the injector device, e.g., similar to the device 6 (i.e., with the injector module located to the right in FIG. 7). Thus, movement of the second ends 166b of the arms proximally causes the pin mount 168 to move distally to open the outlet 44a. Alternatively, the canister 40 may be mounted within an injector device with the outlet 44a oriented distally, i.e., towards the injector module, in which case, distal movement of the second ends 166b moves the pin mount 168 proximally to direct the opener pin 162 to open the outlet 44a.

[0084] In addition, the actuator 112 includes an actuator sleeve 134, which may be slidable relative to the housing 120. For example, the sleeve 134 may be a tubular member mounted concentrically around the housing 120 (e.g., within an outer housing, not shown) such that the sleeve 134 may move axially relative to the housing 120. In one example, the sleeve 134 may be part of a cylinder sleeve that extends concentrically around the drive housing 120, e.g., to a distal or second end of the drive housing 120, e.g., similar to the spacer 30 of the device 6. For example, an activation cap of an injector module (not shown) may be operatively coupled to the sleeve 134 such that, when the activation cap moves, e.g., when a contact surface of the activation cap is pressed against a patient’s skin to insert a needle of the injector module (e.g., similar to the device 6), the axial movement of the activation cap may cause similar axial movement of the sleeve 134. Alternatively, the sleeve 134 may be operatively coupled to a spacer, e.g., similar to the spacer 30 of the device 6) slidably mounted between the sleeve 134 and an activation cap of an injector module.

[0085] The sleeve 134 may include an actuator end 136, e.g., a proximal end where the sleeve 134 extends to the distal end of the drive housing 120 and is operatively coupled to an activation cap of an injector module (not shown). As shown, the proximal end 136 of the sleeve 134 may include a beveled or ramped inner surface 136a, which may be positioned adjacent the second outer ends 166b of the arms 166. As represented by arrows A1, when the sleeve 134 moves proximally (to the left), the ramped surface 136b may contact and push the second ends 166b of the arms proximally, thereby causing the arms 166 to pivot inwardly relative to the pin mount 168, as represented by arrows A2. Alternatively, a slot or other opening (not shown) may be provided adjacent (e.g., distal to)the proximal end 136 of the sleeve 134, which may be aligned to receive the outer end 166b of the arm 166 such that axial movement of the sleeve 134 may direct the outer end 166b axially within the slot.

[0086] With the linkage elements 169 coupled to the arms 166, this inward rotation of the arms 166 causes the pin mount 168 to move distally, as represented by arrow A3. Thus, proximal movement of the sleeve 134 results in distal movement of the pin mount 168 and opener pin 162, thereby directing the opener pin 162 to tear, puncture, or otherwise open the outlet 44a of the canister 40, as shown in FIG. 8B. The pressurized gas therein may then be released, pass through the first chamber 122 into the second chamber, thereby advancing the plunger and piston to deliver the agent(s) within the agent chamber, similar to the other injector devices herein.

[0087] Although the actuator 112 shown in FIGS. 7-8B includes a stationary canister 40 and a movable pin mount 168, it will be appreciated that the components may be reversed, if desired, e.g., such that the pin mount 168 and opener pin 162 are stationary and the linkage moves the canister 40 to open the outlet. Further, although the sleeve 134 may be operatively coupled to an activation cap of the injector module such that proximal movement of the sleeve 134 may open the outlet 44a, alternatively, the sleeve 134 may be configured to move distally to cause the pin mount 168 and opener pin 162 to move proximally to open the outlet. For example, instead of using an activation cap, a manual actuator (not shown) may be provided on the drive housing 120, e.g., proximal to the sleeve 134, that may be pressed, rotated, or otherwise actuated to direct the sleeve 134 distally, thereby directing the pin mount 168 and opener pin 162 proximally to open the outlet.

[0088] In the example shown in FIGS. 7-8B, the arms 166 may be coupled to the pin mount 168 and / or linkage elements 169 by hinges, e.g., including a pin or other element received in a hole or recess, e.g., to allow the arms 169 to rotate freely.

[0089] Alternatively, FIGS. 9A and 9B show an actuator 212, which may include similar components to the actuator 112, e.g., a movable pin mount 268 carrying an opener pin 162 that is coupled to arms 266. In this alternative, first ends 266a of the arms 266 may be pivotally coupled to the pin mount 268 by integral, compliant links, e.g., relatively thin and / or weakened regions that allow the arms 266 to pivot relative to the pin mount 268. Similarly, linkage elements 269 may be integrally attached to the arms 266, e.g., by relatively thin and / or weakened regions. Thus, in this alternative, the arms 266 and linkage elements 269 may be integrally formed together, e.g., by one or more of molding, casting,machining, laser cutting, and the like. Similarly, optionally, the arms 266 may be integrally formed with the pin mount 268 and / or the linkage elements 269 may be integrally formed with stationary mount 221. Thus, in this alternatively, the construction of the actuator 212 may be simplified, e.g., omitting multiple connections that may otherwise require multiple pins or hinges between components that move relative to one another.

[0090] The components may be formed from material that may accommodate relative movement, e.g., material that may deform plastically or elastically to allow the arms 266 and linkage elements 269 to pivot relative to the mounts 221, 268 during operation of the actuator 212. Optionally, the arms 266 may be biased to move away from the outlet 44a, e.g., if desired to have the opener pin 262 automatically retract after opening the outlet 44a.

[0091] Otherwise, the actuator 212 may operate similar to the actuator 112. For example, an actuator sleeve 234 may be provided around the drive housing 220 that may be directed in a first axial direction (e.g., by an activation cap or manual actuator), thereby causing the pin mount 268 and opener pin 262 to move in a second axial direction (opposite the first direction) to cause the opener pin 262 to open the outlet 44a of the canister 44 and activate the injector device, similar to other examples herein.

[0092] It will be appreciated that the configuration of the actuator 112, 212 may be modified, if desired, to provide a mechanical advantage, e.g., that may enhance movement of the opener pin 162, 262 and / or modify the force acting on the outlet 44a of the canister 40. Conversely, the actuator 112, 212 may reduce the activation force acting on the opener pin 162, 262 and outlet 44a, if desired.

[0093] One advantage of the actuators 112, 212 is that they remove a preload provided in an opening mechanism or other spring-loaded actuator. The device 6 includes a puncture spring 66 that biases the carriage 64 once released, which requires storage of substantial potential energy within the (e.g., compressed) spring 66. The linkage mechanism of the actuator 112, 212 removes the need for storing such potential energy, which may extend the shelf life of an injector including the linkage mechanism in place of a spring-loaded actuator.

[0094] While the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to theparticular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the scope of the appended claims.

Claims

I CLAIM:

1. A drive module for delivering one or more agents into a patient’s body from an injector module comprising an agent chamber containing one or more agents and a piston, the drive module comprising: a drive housing including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; an opening mechanism within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; an actuator configured to move one of the opening mechanism and the canister to cause the opener pin to open the outlet and cause the gas within the canister to flow from the first chamber into the second chamber; and a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, the plunger configured to be coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber, wherein the actuator comprises a springless mechanism configured to move one of the opening mechanism and the canister to cause the opener pin to open the outlet.

2. The drive module of claim 1, wherein the actuator comprises an actuator sleeve that is movable axially relative to the drive housing, and a linkage mechanism coupled to one of the opening mechanism and the canister, the actuator sleeve configured to cause the linkage mechanism to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet.

3. The drive module of claim 2, wherein the actuator sleeve is configured to slide axially over an exterior of the drive housing, and wherein the linkage mechanism comprises one or more arms that extend from the drive housing such that the actuator sleeve contacts the one or more arms to cause the linkage mechanism to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet.

4. The drive module of claim 2 or 3, wherein the linkage mechanism comprises a plurality of links configured to provide a mechanical advantage to reduce the activation force required to open the outlet.

5. The drive module of claim 2, wherein the actuator further comprises a manual actuator on the drive module that may be manually activated by a user to move the actuator sleeve.

6. The drive module of claim 5, wherein the manual actuator comprises one of a screw, a button, and a lever.

7. The drive module of claim 2 or 3, further comprising an activation cap adjacent the second end of the drive housing such that a contact surface is disposed distal to the second end, the activation cap movable axially relative to the drive housing such that, when the contact surface of the activation cap is pressed against a subject’s skin, the activation cap moves proximally to direct the actuator sleeve to cause the linkage mechanism to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet.

8. The drive module of claim 2 or 3, wherein the activation sleeve is configured to move in a first axial direction and wherein the linkage mechanism causes the pin mount to move axially in a second axial direction opposite the first axial direction.

9. The drive module of claim 3, wherein the opener pin is carried on a pin mount and wherein the arms comprise first ends that are pivotally coupled to the pin mount and second ends that are positioned adjacent the actuator sleeve such that movement of the actuator sleeve moves the second ends to cause the pin mount and opener pin to move axially.

10. The drive module of claim 9, wherein each of the first ends of the arms are coupled to the pin mount by a hinge.

11. The drive module of claim 9, wherein each of the first ends of the arms are integrally coupled to the pin mount.

12. The drive module of claim 10 or 11, wherein the linkage mechanism comprises linkage arms pivotally coupled between the arms and a stationary mount axially fixed relative to the drive housing.

13. The drive module of claim 12, wherein opposite ends of the linkage arms are coupled to the arms and the stationary mount by hinges.

14. A drive module for delivering one or more agents into a patient’s body from an injector module comprising an agent chamber containing one or more agents and a piston, the drive module comprising: a drive housing including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; a pin mount within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, the plunger configured to be coupled to the piston of the injector module to advance the piston of the injector module to deliver one or more agents from the agent chamber; an actuator sleeve adjacent the drive housing configured to be operatively coupled to an actuator to direct the actuator sleeve axially in a first direction relative to the drive housing; and a linkage mechanism coupled to one of the pin mount and the canister, the actuator sleeve configured to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

15. The drive module of claim 14, wherein the linkage mechanism comprises one or more arms that extend from the drive housing such that the actuator sleeve contactsthe one or more arms to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

16. The drive module of claim 15, wherein the linkage mechanism is configured to move the pin mount in a second direction opposite the first direction to direct the opener pin to open the outlet.

17. The drive module of any one of claims 14-16, wherein the linkage mechanism comprises a plurality of links configured to provide a mechanical advantage to reduce the activation force required to open the outlet.

18. The drive module of any one of claims 14-16, wherein the actuator further comprises a manual actuator on the drive module that may be manually activated by a user to move the actuator sleeve.

19. The drive module of claim 18, wherein the manual actuator comprises one of a screw, a button, and a lever.

20. The drive module of any one of claims 14-16, wherein the actuator sleeve is configured to be coupled to an activation cap of an injector module coupled to the drive module such that, when a contact surface of the activation cap is pressed against a subject’s skin, the activation cap moves proximally to direct the actuator sleeve to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

21. An injector device, comprising: a) an injector module comprising an agent chamber containing one or more agents and a piston; and b) a drive module comprising: a drive housing including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; an opening mechanism within the first chamber including an opener pin;a canister containing pressurized gas including an outlet disposed adjacent the opener pin; an actuator configured to move one of the opening mechanism and the canister to cause the opener pin to open the outlet and cause the gas within the canister to flow from the first chamber into the second chamber; and a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, a distal end of the plunger coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber, wherein the actuator comprises a springless mechanism configured to move one of the opening mechanism and the canister to cause the opener pin to open the outlet.

22. The injector device of claim 21, wherein the actuator comprises an actuator sleeve that is movable axially relative to the drive housing, and a linkage mechanism coupled to one of the opening mechanism and the canister, the actuator sleeve configured to cause the linkage mechanism to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet.

23. The injector device of claim 22, wherein the actuator sleeve is configured to slide axially over an exterior of the drive housing, and wherein the linkage mechanism comprises one or more arms that extend from the drive housing such that the actuator sleeve contacts the one or more arms to cause the linkage mechanism to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet.

24. The injector device of claim 22 or 23, wherein the linkage mechanism comprises a plurality of links configured to provide a mechanical advantage to reduce the activation force required to open the outlet.

25. The injector device of claim 21, wherein the actuator further comprises a manual actuator on the drive module that may be manually activated by a user to move the actuator sleeve.

26. The injector device of claim 25, wherein the manual actuator comprises one of a screw, a button, and a lever.

27. The injector device of claim 21 or 22, further comprising an activation cap adjacent the injector module such that a contact surface is disposed distal to the injector module, the activation cap movable axially relative to the drive housing such that, when the contact surface of the activation cap is pressed against a subject’s skin, the activation cap moves proximally to direct the actuator sleeve to cause the linkage mechanism to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet.

28. An injector device, comprising: a) an injector module comprising an agent chamber containing one or more agents and a piston, and an activation cap; and b) a drive module comprising: a drive housing including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; a pin mount within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, the plunger configured to be coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber; an actuator sleeve adjacent the drive housing operatively coupled to the actuator to direct the actuator sleeve axially in a first direction relative to the drive housing; and a linkage mechanism coupled to one of the pin mount and the canister, the actuator sleeve configured to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

29. The device of claim 28, wherein the linkage mechanism comprises one or more arms that extend from the drive housing such that the actuator sleeve contacts the oneor more arms to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

30. The device of claim 29, wherein the linkage mechanism is configured to move the pin mount in a second direction opposite the first direction to direct the opener pin to open the outlet.

31. The device of any one of claims 28-30, wherein the linkage mechanism comprises a plurality of links configured to provide a mechanical advantage to reduce the activation force required to open the outlet.

32. The device of any one of claims 28-30, wherein the actuator sleeve is coupled to the such that, when a contact surface of the activation cap is pressed against a subject’s skin, the activation cap moves proximally to direct the actuator sleeve to cause the linkage mechanism to move the one of the pin mount and the canister to cause the opener pin to open the outlet.

33. An injector device, comprising: a) an injector module comprising an agent chamber containing one or more agents and a piston; and b) a drive module comprising: a drive housing including a first end and a second end, a first chamber adjacent the first end communicating with a second chamber adjacent the second end; a pin mount within the first chamber including an opener pin; a canister containing pressurized gas including an outlet disposed adjacent the opener pin; a plunger comprising a proximal end slidably disposed within the second chamber such that the gas entering the second chamber causes the plunger to move from an initial position to an extended position, the plunger configured to be coupled to the piston of the injector module to advance the piston of the injector module to deliver the one or more agents from the agent chamber; an actuator sleeve adjacent the drive housing operatively coupled to the actuator to direct the actuator sleeve axially in a first direction relative to the drive housing; anda linkage mechanism coupled to one of the pin mount and the canister, the actuator sleeve configured to cause the linkage mechanism to move the one of the opening mechanism and the canister to cause the opener pin to open the outlet.

34. The injector device of claim 33, wherein the actuator further comprises a manual actuator on the drive module that may be manually activated by a user to move the actuator sleeve.

35. The injector device of claim 34, wherein the manual actuator comprises one of a screw, a button, and a lever.

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