WO2001017592A1

WO2001017592A1 - Needleless injector system

Info

Publication number: WO2001017592A1
Application number: PCT/US2000/023897
Authority: WO
Inventors: R. Samson Callender; William D. Brown; Jerald C. Umbaugh
Original assignee: GENESIS MEDICAL TECHNOLOGIES Inc
Current assignee: GENESIS MEDICAL TECHNOLOGIES Inc
Priority date: 1999-09-03
Filing date: 2000-08-31
Publication date: 2001-03-15
Anticipated expiration: 2002-03-03
Also published as: AU7094500A

Abstract

A needleless injection system (10) that includes an actuator (14) having a housing (16), a compressible energy storage member (32) within the housing (16), a piston (46) connected to the energy storage member (32), the piston (46) being retained within the housing (16), and a trigger mechanism (24) for retaining the energy storage member (32) in its energized or loaded position and selectively releasing the energy storage member so that it drives the piston. A removable medicament vial (12), the removable medicament vial (12) being attachable to the housing (16) of the actuator, removal of the vial (12) from the housing (16) further providing access to the piston (46) in order to allow loading of the energy storage member (32). A separate re-energizing station (122) is also provided for reloading of the compressible energy storage member to prepare the device for a succeeding injection.

Description

DESCRIPTION

NEEDLELESS INJECTOR SYSTEM

Technical Field

This invention generally relates to a medicament injection system, and more particularly, but not by way of limitation, to a needleless injection device which can be energized by way of an external mechanical cocking unit.

Background Art

The advantages of the providing medicinal injections with a needleless injection device have long been recognized. The development of an inexpensive needleless device that allows the injection of medicament through the skin has proven to be a difficult and elusive search for the combination of components that can deliver a very fine stream of medicament at a sufficiently high pressure to pierce the skin and deliver the medicament to the desired location below the skin's surface.

Some of the problems associated with needleless injectors include the need to deliver a smooth, steady stream of medicament in a short time. It has been recognized that the ideal device would use a strong spring which would display an insignificant amount in the reduction of force as the spring is used to propel the medicament from the needleless injector. The use of a spring has been disfavored by many due to the large force needed to compress a spring with the required mechanical properties for propelling the medicament subcutaneously.

Other approaches at providing a suitable energy source for delivering the medicament through a needleless injector have focused on the use of a compressed gas as the energy source for driving a piston that pushes the medicament through a very small aperture in the injection device. This approach has resulted in devices that require a large number of moving parts, including valves, measuring or limiting systems, and compressors or compressed gas containers. These compressed gas systems have been successful in delivering the needed energy, but have acquire limited acceptance due to the expense associated with producing these complicated, precision mechanisms.

Still further, another problem faced by needleless injection devices is that even though the devices do not have mechanical components that invade or enter the body, they suffer from cross contamination associated with the intimate contact of the nozzle of the injection device and the area of the skin which was penetrated by the stream of medicament. This problem can be particularly troublesome for pneumatic devices that use a medicament reservoir and that measures and delivers medicament from this reservoir through a single nozzle.

Thus a review of known devices reveals that there remains a need for a needleless injector device or system that is simple, inexpensive, easy to use, effective, and obviates the problems associated with cross contamination. We have invented such a system.

Disclosure of Invention

It has been discovered that the problems left unanswered by known art can be solved by providing a needleless injection system that includes: an actuator having: a housing: a compressible energy storage member within the housing; a piston connected to the energy storage member, the piston being retained within the housing; and a trigger mechanism for retaining the energy storage member in its energized or loaded position, and selectively releasing the energy storage member so that it drives the piston; and a removable medicament vial, the removable medicament vial being attachable to the housing of the actuator, removal of the vial from the housing further providing access to the piston in order to allow loading of the energy storage member.

According to a highly preferred embodiment of the invention, a connecting rod cooperates with the piston to move a plunger through the vial and drive the medicament from the vial through a small aperture in the vial. The plunger forms a tight seal against the walls of the vial. The connecting rod is attached to the plunger in a manner that allows the connecting rod to push the plunger into the vial, but permits the connecting rod to disconnect from plunger when one tries to pull the connecting rod from the vial. This results in a single use vial and plunger group which cannot be easily reused. This in turn provides for a disposable vial and plunger assembly that allows only one use of the vial and plunger assembly per injection. Still further, according to a highly preferred embodiment of the invention, the energy storage member cooperates with a cocking mechanism which uses a mechanical advantage to energize or reload the energy storage member to allow the energy storage member to drive the piton, connecting rod, and plunger through the vial to deliver a stream of medicament at the desired rate.

An important aspect of the vial design is that it includes a nozzle end and a housing connection end. The nozzle end includes a ring that surrounds the nozzle, and the nozzle is defined from a portion that protrudes from a location within the ring. This ring cooperates with the protruding nozzle to stretch the skin to the point where the skin is drawn taught in front of the nozzle, and thus taking up the stretch in the skin to provide a target that does not absorb as much of the energy from the stream of medicament.

Still further, it is contemplated that the vial, medicament and plunger assembly may be provided as a single use unit, which provides a single, pre-measured dose of medicament in a disposable, single-use vial and plunger assembly.

It should also be understood that while the above and other advantages and results of the present invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings, showing the contemplated novel construction, combinations and elements as herein described, and more particularly defined by the appended claims, it should be clearly understood that changes in the precise embodiments of the herein disclosed invention are meant to be included within the scope of the claims, except insofar as they may be precluded by the prior art. DRAWINGS

The accompanying drawings illustrate preferred embodiments of the present invention according to the best mode presently devised for making and using the instant invention, and in which:

FIG. 1 is a perspective view of a highly preferred embodiment of the invention while held in a person's hand.

FIG. 2 is a section taken in the direction indicated on FIG. 1, and illustrating the major components of a highly preferred embodiment in an exploded manner.

FIG. 3 is a section taken in the same direction as FIG. 2, and illustrating the major components of the invention assembled and in an unloaded position. The vial and connecting rod used with a highly preferred embodiment of the invention is not shown in this figure.

FIG. 4 illustrates the assembly shown on FIG. 3 in a cocked or loaded position.

FIG. 5 illustrates a section similar to FIG. 4, the view illustrating a highly preferred embodiment in a cocked or loaded position with a vial, connecting rod, and plunger attached prior to firing of the device.

FIG. 6 illustrates the assembly of FIG. 5 immediately after the opposable trigger mechanism has been squeezed and the piston has driven the connecting rod together with the plunger into the vial to deliver a stream of medication.

FIG. 7 illustrates the separation of the connecting rod and the plunger after the plunger has reached the bottom of the vial . FIG. 8 illustrates the use of a hand operated cocking mechanism to use a mechanical advantage to compress the spring of a highly preferred embodiment of the invention after the connecting rod and vial have been removed after firing. to o en o

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indicated on FIG. 1. As can be understood from FIG. 2, the actuator 14 will include a compressible energy storage member 30, which in a highly preferred embodiment of the invention is a spring 32. Preferably, the spring 32 will be contained in a cylinder 34 which in a preferred embodiment is made of a strong metal such as steel. One end 36 of the cylinder 34 has a retainment plug 35, which can also serve as an adjustment plug. The opposite end 38 of the cylinder 34 has a retainment wall 40 with an aperture 42 therethrough. The sides 44 of the cylinder 34 include side apertures 46 which provide access to the interior of the cylinder 34, so that the trigger mechanism 24 to cooperate with the systems held within the cylinder 34.

Also shown on FIG. 2 is that a piston 46 is connected to the energy storage member 30 and held within the cylinder 34, biased against the retainment wall 40 by the spring 32. In a preferred embodiment, the piston 46 includes an elongated body 48 having a first end 50, a second end 52 and a mid-portion 54. As illustrated, second end 52 of the piston 46 includes means for accepting thrust from the energy storage member, or spring 32. Additionally, the first end 50 of the piston 46 includes means for engaging a connecting rod 56 which is used to transmit power from the spring 32 towards the vial 12. Additionally, the first end 50 of the piston 46 includes a surface 58 for engaging the trigger mechanism 24.

Also illustrated on FIG. 2 is that a highly preferred embodiment of the trigger mechanism 24 includes a pair of pivoting levers 60 that are biased to a locking position by leaf springs 65. Each of the levers 60 includes a pivot pin 62 that mounts against the housing 16. Additionally, the levers 60 will include a protrusion 64 that serves for engaging the surface 58 on the first end 50 of the piston 46 ) t σ o

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The body 87 of the vial 12 will preferably be hollow, and include an aperture 84 with a surface 86 that extends to the first end 70 of the vial 12, providing fluid communication between the second end 72 of the vial 12 and the aperture 88 through the nozzle 76. To drive medicament from within the body 87 of the vial 12, a plunger 90 is provided for sealingly engaging the surface 86 of the aperture 84 of the vial 12. The plunger 90 includes a leading end 92 and a trailing end 94. The trailing end 94 includes means 96 for accepting the connecting rod 56.

Preferably, the means 96 for accepting the connecting rod 56 will include an aperture 98 of a diameter 100. This aperture 98 will cooperate with a post 102 on the end 104 of the connecting rod 56. The post 102 will be of a diameter 106 that slightly larger than the diameter 100 of the aperture 98 in the plunger 90, so that the post 102 produces a releasable interference fit against the aperture 98 in the plunger 90. It is contemplated that this arrangement will allow the plunger 90 to be retained against the connecting rod 56 and allow transfer of the spring force through the connecting rod 56 against the plunger 90 as the plunger is moved through the aperture 84 in the body 87 of the vial 12 to drive medicament through the nozzle 76, but this connection will release the connecting rod 56 from the plunger 90 if the connecting rod is pulled from the plunger 90, towards the second end 72 of the vial 12. It will be understood that this connection will result in a single use plunger 90 and vial 12 assembly. Additionally, it is contemplated that the vial 12, plunger 90 assembly may be sold or distributed as a pre-measured dose unit, with a removable protective seal over the first end 70 of the vial and another seal over the second end 72 of the vial 12 to ensure hermetic containment of the medicament and plunger 90 within the vial 12. In operation, the user would simply remove the seals from the first end 70 and second end 72 of the vial 12, place the plunger 90 against the connecting rod 56 and install the assembly on the housing 16 of the actuator 14.

Turning now to FIG. 3, which is a section taken in the same direction as FIG. 2, where the trigger mechanism 24 has been shown mounted on the housing 16. In this figure, the piston 46 is shown after firing of the system 10 and after removal of the used vial 12, together with the connecting rod. Thus the protrusions 64 of the trigger mechanism 24 are biased against the sides of the mid-portion 54 of the piston, as the piston 46 is biased against the retaining wall 40 of the cylinder 34 by the spring 32.

To prepare the system 10 for a shot, the piston 46 must be driven back into the spring 32 until the protrusions 64 on the levers 60 of the trigger mechanism 26 engage the surface 58 on the piston 46, as shown on FIG. 4. To further prepare the system for delivery of a shot, the connecting rod 56 is inserted and brought to bear against the piston

46, as shown on FIG. 5. Additionally, a vial 12, filled with medicament 110 and with any protective seals removed from its ends, is attached to the first end 18 of the housing 16. The system 10 is now ready for delivering a shot or injection to the patient.

Turning now to FIG. 6, where the firing of the system 10 has been illustrated. To fire or release the piston 46, the user simply squeezes the opposing levers 60 of the trigger mechanism 24 in the direction of arrows 112, causing the spring 32 to drive the piston 46, connecting rod 56, and plunger 90 in the direction of arrow 114, producing the fine stream 116 of medicament 110 that penetrates the skin and body of the patient. Turning now to FIG. 7, it will be understood that after the injection, the vial 12 is removed from the housing 16, and removal of the connecting rod is carried by simply pulling the connecting rod 56 in the direction of the arrow 118, leaving the plunger 90 in the vial 12.

FIG. 8 illustrates the use of an important component of the system 10. After the actuator 14 has been fired, and the internal mechanism returns to the position shown on FIG. 3, the reloading or compressing of the spring needs to be carried out to prepare for the nest shot. To compress the spring 32 a means for restraining the actuator 14 and compressing the spring 56 is used to hold the actuator while a pressing ram 120 is used to push the spring 32 back to the position shown in FIG. 4.

Thus FIG. 8 shows a reloading device 122 includes means for restraining the actuator 14 and pressing ram 120. The pressing ram 120 in the illustrated embodiment is driven back into the actuator 14 with the use of a lever 124 once the vial 12 and the connecting rod 56 have been removed. The hand operated lever 124 simply uses a mechanical advantage to push a linkage 126 that drives the ram 120 into the actuator 14 in the direction shown by arrow 128, pressing the piston 46 against the spring 32 until the trigger mechanism 24 locks the piston in the position shown on FIG. 4.

It is important to note that it is contemplated that the lever 124 could be actuated by hand or foot or remotely by cable. Additionally, it is contemplated that the connecting rod 56 may be permanently attached to the piston 46, wherein the ram 120 will push against the connecting rod 56 in reloading the system. Thus it can be appreciated that the above described embodiments are illustrative of just a few of the numerous variations of arrangements of the disclosed elements used to carry out the disclosed invention. Moreover, while the invention has been particularly shown, described and illustrated in detail with reference to preferred embodiments and modifications thereof, it should be understood that the foregoing and other modifications are exemplary only, and that equivalent changes in form and detail may be made without departing from the true spirit and scope of the invention as claimed, except as precluded by the prior art.

Claims

1. A needless injector system comprising: an actuator comprising: a housing; a compressible energy storage member within the housing; a piston connected to the energy storage member, the piston being retained within the housing; a trigger mechanism for selectively retaining and releasing the energy storage member from a compressed or energized position, so that on release of the energy storage member the energy storage member expands moving the piston; and the housing further having means for receiving and holding a removable medicament vial, removal of the vial from the housing further providing access to the piston in order to allow loading of the energy storage member; and means for restraining said actuator and compressing the compressible energy storage member through the means for receiving and holding a removable medicament vial while restraining said actuator, so that the actuator is energized by exerting a co pressive force against the piston through the means for receiving and holding a removable medicament vial .

2. A system according to claim 1 wherein said trigger mechanism comprises a pair of pivoting levers, each lever having a protrusion for engaging the piston, so that the piston is released by releasing contact of the protrusion of both levers simultaneously.

3. A system according to claim 1 and further comprising a vial having a first end and a second end, the first end of the vial having a ring, a nozzle centered within the ring, and an -14-

annular recessed area between the nozzle and the ring, the nozzle extending further from the second end than the ring.

4. A system according to claim 1 and further comprising a vial having a first end and a second end and an aperture having a surface, the aperture extending from the second end towards the first end, the first end terminating in a nozzle, the second end of the vial having means for engaging the means for receiving and holding a removable medicament vial of said housing.

5. A system according to claim 4 wherein the means for means for engaging the receiving and holding a removable medicament vial of said housing comprises a pair of tabs extending away from each other in a generally radial manner from said vial.

6. A system according to claim 4 and further comprising a plunger adapted for sealingly engaging the surface of the aperture of the vial, the plunger having a leading end and a trailing end, the trailing end having means for accepting a connecting rod, the connecting rod being adapted for rigidly extending from the piston to the trailing end of the plunger.

7. A system according to claim 6 wherein said means for accepting the connecting rod includes an aperture of a diameter, and the connecting rod includes a post of a diameter that slightly larger than the diameter of the aperture in the plunger, so that the post in the connecting rod produces an interference fit against the aperture in the plunger when inserted in the aperture in the plunger.

8. A system according to claim 6 wherein said piston includes an elongated body having a first end, a second end and a mid-portion, the second end having means for accepting thrust from the energy storage member, and the first end having means for engaging the connecting rod and a surface for engaging the trigger mechanism.

9. A system according to claim 8 wherein said trigger mechanism comprises a pair of pivoting levers, each lever having a protrusion for engaging the surface for engaging the trigger mechanism of the piston, so that the piston is released by releasing contact of the protrusion of both levers simultaneously.

10. A system according to claim 9 wherein said levers are pivotable along a single plane.

11. A needless injector system comprising: an actuator comprising: a housing; a helical spring within the housing; a piston connected to the energy storage member, the piston being retained within the housing; a trigger mechanism for selectively retaining and releasing the energy storage member from a compressed or energized position, so that on release of the energy storage member the energy storage member expands moving the piston; the housing further having means for receiving and holding a removable medicament vial, removal of the vial from the housing further providing access to the piston in order to allow loading of the energy storage member ; and means for restraining said actuator and compressing the helical spring through the means for receiving and holding a removable medicament vial while restraining said actuator, so that the actuator is energized by exerting a compressive force against the piston through the means for receiving and holding a removable medicament vial .

12. A system according to claim 11 wherein said trigger mechanism comprises a pair of pivoting levers, each lever having a protrusion for engaging the piston, so that the piston is released by releasing contact of the protrusion of both levers simultaneously.

13. A system according to claim 11 and further comprising a vial having a first end and a second end, the first end of the vial having a ring, a nozzle centered within the ring, and an annular recessed area between the nozzle and the ring, the nozzle extending further from the second end than the ring.

14. A system according to claim 11 and further comprising a vial having a first end and a second end and an aperture having a surface, the aperture extending from the second end towards the first end, the first end terminating in a nozzle, the second end of the vial having means for engaging the means for receiving and holding a removable medicament vial of said housing.

15. A system according to claim 14 wherein the means for means for engaging the receiving and holding a removable medicament vial of said housing comprises a pair of tabs extending away from each other in a generally radial manner from said vial.

16. A system according to claim 14 and further comprising a plunger adapted for sealingly engaging the surface of the aperture of the vial, the plunger having a leading end and a trailing end, the trailing end having means for accepting a connecting rod, the connecting rod being adapted for rigidly extending from the piston to the trailing end of the plunger.

17. A system according to claim 16 wherein said means for accepting the connecting rod includes an aperture of a diameter, and the connecting rod includes a post of a diameter that slightly larger than the diameter of the aperture in the plunger, so that the post in the connecting rod produces an interference fit against the aperture in the plunger when inserted in the aperture in the plunger.

18. A system according to claim 16 wherein said piston includes an elongated body having a first end, a second end and a mid-portion, the second end having means for accepting thrust from the energy storage member, and the first end having means for engaging the connecting rod and a surface for engaging the trigger mechanism.

19. A system according to claim 18 wherein said trigger mechanism comprises a pair of pivoting levers, each lever having a protrusion for engaging the surface for engaging the trigger mechanism of the piston, so that the piston is released by releasing contact of the protrusion of both levers simultaneously.

20. A method for delivering a series of injections of medicament with a spring loaded needleless injector, the method comprising: providing an actuator for providing the mechanical energy for actuating a plunger driven needleless injection device; providing a means for retaining the actuator and reloading the actuator energy, the actuator being separately operable from the means for retaining and reloading; delivering an injection of medicament with the actuator; and recharging the mechanical energy of the actuator for actuating a plunger driven needleless injection device with the means for retaining the actuator and reloading the actuator energy.