Single-use needle-less hypodermic jet injection apparatus and method

• US 6,264,629 B1
• Filed: 02/18/1999
• Issued: 07/24/2001
• Est. Priority Date: 11/18/1998
• Status: Expired

• Current Assignee: Bioject Incorporated
• Original Assignee: Bioject Incorporated
• Inventors: Landau, Sergio
• Primary Examiner(s): Seidel, Richard K.
• Assistant Examiner(s): HAYES, MICHAEL J
• Application Number:
  US09/252,131
• Time in Patent Office: 887 Days
• Field of Search: 604/68-72, 604/140, 604/141, 604/143, 604/148, 604/232, 604/131
• US Class Current: 604/68
• CPC Class Codes: A61M 2005/2073 preventing premature release, e.g. by making use of a safety lock
• CPC Class Codes: A61M 2005/2462 by displacing occluding plugs
• CPC Class Codes: A61M 2005/3132 having flow passages for injection agents at the distal end of the barrel to bypass a sealing stopper after its displacement to this end due to internal pressure increase
• CPC Class Codes: A61M 5/2053 Media being expelled from injector by pressurised fluid or vacuum for infusion A61M5/145, A61M5/155
• CPC Class Codes: A61M 5/2459 upon internal pressure increase, e.g. pierced or burst A61M5/2429 takes precedence
• CPC Class Codes: A61M 5/30 Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence

Abstract

A gas-powered, single-use, needle-less hypodermic jet injection device includes a hand-held injector, and a drug injection cartridge which provides a cylinder of liquid medication to be injected, an injection orifice, and an injection piston. Forceful movement of the injection piston in the cylinder causes an injection jet of medication to be expelled from the injection orifice. The injection device also includes a hermetically sealed gas pressure capsule which remains sealed until the moment of injection and powers the jet injection after opening of this cartridge.

Claims

1. A needle-less hypodermic jet injection device comprising:

a pre-filled drug injection cartridge including;

a medication cylinder having an outlet orifice,

an injection nozzle,

a flow path communicating the outlet orifice to said injection nozzle,

a drug-injection piston in a first position cooperating with said medication cylinder to define a variable-volume chamber of first selected size,

a dose of substantially incompressible liquid medication substantially filling said variable-volume chamber at said first size with substantially no ullage volume,

said drug-injection piston having a second position cooperating with said medication cylinder to define a variable-volume chamber of second selected size smaller than said first selected size;

a hand piece assembly having a body holding said drug injection cartridge, said hand piece assembly including a source of pressurized gas, and means for selectively applying force from said pressurized gas to said drug injection piston to move said drug injection piston from said second position to a third position substantially ejecting said dose of liquid medication via said injection nozzle;

said hand piece assembly including a first body portion holding said drug injection cartridge, and a second body portion manually movable relative to said first body portion, said second body portion including an abutment member selectively movable into engagement with said drug injection piston in response to manual relative movement of said first and second body portions to move said drug injection piston from said first position to said second position.

2. The device of claim 1, wherein said hand piece assembly further includes a first bore within said first body portion, a gas power piston movably received in said bore and having a ram portion extending into said drug injection cartridge to abut with said drug-injection piston, said body and gas-power piston cooperating to define a first variable-volume gas-power chamber in said first bore;

said hand piece assembly further including a second body portion adjustably engaging with said first body portion, said second body portion defining an elongate second bore in gas flow communication with said first bore gas-power chamber and separated therefrom by a wall portion carried by said second body portion.

3. The device of claim 2 wherein said first body portion and said second body portion are threadably and adjustably engaged with one another, said second body portion carrying said abutment member.

4. The device of claim 3 wherein said wall portion includes said abutment member.

5. The device of claim 2 wherein said second body portion in said second bore further carries a cylindrical gas capsule, said cylindrical gas capsule providing said source of pressurized gas.

6. The device of claim 5 wherein said hand piece assembly second body portion is cylindrical, and a tubular trigger sleeve is movably carried by said second body portion to effect opening of said gas capsule.

7. A needle-less hypodermic jet injection device comprising:

a pre-filled drug injection cartridge including;

a medication cylinder having an outlet orifice, a plug member in a first position sealingly closing the outlet orifice, an injection nozzle, a flow path communicating the outlet orifice to said injection nozzle and providing a chamber for capturing said plug member in a second position, a drug-injection piston in a first position cooperating with said medication cylinder to define a variable-volume chamber of first selected size, a dose of substantially incompressible liquid medication substantially filling said variable-volume chamber at said first size with substantially no ullage volume, said drug-injection piston having a second position cooperating with said medication cylinder to define a variable-volume chamber of second selected size sufficiently smaller than said first selected size that said plug member is hydraulically forced from said first position at said outlet orifice and to a second position in said chamber;

a hand piece assembly having a two-piece body having a first body portion holding said drug injection cartridge, and a second body portion providing an abutment movable relative to said first body portion to move said drug injection piston between said first and second positions;

a source of pressurized gas including a hermetically sealed metallic gas capsule;

trigger means for selectively penetrating said gas capsule and for applying force from said pressurized gas to said drug injection piston to move said drug injection piston from said second position to a third position substantially ejecting said dose of liquid medication via said injection nozzle.

8. The device of claim 7, wherein said first body portion defines a first bore, a gas-power piston movably received in said first bore, said gas-power piston having a piston head and a ram portion extending into said drug injection cartridge to abut with said drug-injection piston, said first body portion and said gas-power piston cooperating to define a first variable-volume gas-power chamber in said first bore;

said second body portion sealingly and movably engaging with said first body portion to bound said gas-power chamber, said second body portion defining an elongate second bore in gas flow communication with said gas-power chamber, and said gas capsule being received into said second bore.

9. The device of claim 8 wherein said first body portion and said second body portion are threadably and adjustably engaged with one another, said second body portion including said abutment on a wall portion separating said second bore from said gas-power chamber.

10. A jet injection device comprising:

a drug cartridge having a cylinder in which is movable a piston to cooperatively define a variable-volume chamber for holding a dose of liquid medication;

a fine-dimension injection orifice in liquid flow communication with the variable-volume chamber to receive the liquid medication and discharge this medication as a high velocity forceful jet for hypodermic jet injection of the medication upon forceful movement of said piston in said cylinder;

a power source for forcefully moving said piston in said cylinder in response to triggering of said injection device, and

a trigger assembly for initiating forceful movement of said piston, said trigger assembly including a hammer member having a plurality of legs each having an end surface, a sear ring member upon which said end surfaces of said legs rests in a first position of the hammer member, means for urging said hammer member to a second position, and a trigger sleeve surrounding said hammer member and having a respective plurality of contact portions each engaging one of the plurality of legs to move said legs out of engagement with said sear ring upon axial movement of said trigger member.

11. The injection device of claim 10 wherein said hammer member includes a central wall portion from which extends in one axial direction a skirt defining a spring seat, said power source including a spring received into said skirt and into engagement with said central wall portion, said multitude of legs extending axially from said central wall portion in an opposite axial direction.

12. The injection device of claim 11 wherein said hammer member is a unitary molding of plastic polymer.

13. The injection device of claim 10 wherein said hammer member includes a first circular cylindrical portion and a second conically flaring portion axially arranged with one another.

14. The injection device of claim 13 wherein said first circularly cylindrical portion extends in one direction from said central wall portion, and said plurality of legs cooperatively define said second conically flaring portion and extend axially in said opposite axial direction from said central wall portion.

15. The injection device of claim 14 wherein said conically flaring portion has a conical diameter at an end of said hammer member, said plurality of legs are each part-circular segments having circular radii which are substantially equal to the radius of the circular cylindrical portion, whereby, said sear ring has an inner diameter substantially equal to said circular cylindrical portion of said hammer member and said plurality of legs in a second position are nested circumferentially adjacent to one another within said sear ring member.

16. A unitary elongate molded plastic polymer hammer member, said hammer member comprising:

a central wall portion extending radially;

a circular cylindrical portion extending axially in one direction from said central wall portion, said circular cylindrical portion including a tubular skirt and cooperating with said central wall portion to define a spring seat into which a spring may be received to engage upon said central wall portion;

a conically flaring portion extending in an opposite axial direction from said central wall portion, said conical portion including a plurality of circumferentially spaced apart resilient legs each extending axially to terminate in a respective axial end surface engageable with a sear ring in a first position of the legs to support said hammer member in opposition to force from the spring exerted on said central wall portion, said legs in said first position cooperatively defining a conical diameter at said end surfaces, and said legs at said end surfaces each also defining a circular radius which are substantially equal to the radius of said circular cylindrical portion;

whereby, said plurality of legs are movable to a second position in opposition to said resilience of said legs, in said second position said plurality of legs being circumferentially nested adjacent to one another and cooperatively defining a diameter substantially equal to that of said cylindrical portion.

17. A method of operating a needle-less hypodermic jet injection device using an injection cartridge having a cylinder receiving liquid medication, an orifice for forming the liquid into a high-velocity hypodermic injection jet, a plug member in a first position sealingly separating said medication from said orifice, and said plug member in a captive second position allowing communication of medication to said orifice, and an injection piston movable sealingly in said cylinder to displace said liquid medication via said orifice;

said method including steps of;

providing said device with a two-piece body having a first body portion defining a first bore into which is received a gas-power piston, and a second body portion defining a second bore into which is sealingly and movably received a hermetically sealed pressurized gas capsule;

utilizing said first and second body portions and said gas-power piston to cooperatively define a variable-volume chamber; and

first relatively moving said first and second body portions to forcefully move said plug member from said first position to said captive second position to unseal said injection cartridge, and then

utilizing communication of pressurized gas from said pressurized gas capsule into said variable-volume chamber to forcefully move said gas-power piston to displace said liquid medication from said cartridge via said orifice to effect a hypodermic jet injection.

18. The method of operating a needle-less injection device of claim 17 further including the step of utilizing a unitary molded plastic polymer hammer member to drive said gas capsule upon an impaling spike communicating pressurized gas to said variable-volume chamber.

19. A method of operating a needle-less hypodermic jet injection device using an injection cartridge having a cylinder receiving liquid medication, an orifice for forming the liquid into a high-velocity hypodermic injection jet, a plug member sealingly separating said medication from said orifice, and an injection piston movable sealingly in said cylinder to displace said liquid medication via said orifice;

said method including steps of;

providing said device with a two-piece body having a first body portion defining a first bore into which is received a gas-power piston, and a second body portion defining a second bore into which is sealingly and movably received a hermetically sealed pressurized gas capsule;

utilizing said first and second body portions and said gas-power piston to cooperatively define a variable-volume chamber; and

first relatively moving said first and second body portions to forcefully move said plug member to unseal said injection cartridge, and then

utilizing communication of pressurized gas from said pressurized gas capsule into said variable-volume chamber to forcefully move said gas-power piston to displace said liquid medication from said cartridge via said orifice to effect a hypodermic jet injection;

further including the step of providing said molded unitary plastic polymer hammer member with a plurality of axially extending legs each having an end surface engaging upon a sear ring surface to support said hammer member, and simultaneously slipping said plurality of legs off of said sear ring surface radially inwardly to be received in circumferentially adjacent nested position within said sear ring surface to allow axial movement of said hammer member.

20. A needle-free hypodermic jet injection device comprising:

a body substantially formed of plastic polymer;

a jet injection cartridge carried by said body and including a cylinder and piston cooperatively defining a variable-volume chamber receiving a dose of liquid medication, and a fine-dimension jet injection orifice in liquid flow communication with said variable volume chamber;

a metallic pre-filled hermetically-sealed single-use gas pressure cartridge axially movably disposed in said body, said gas pressure cartridge having a penetrable wall portion and said body including a penetrator axially spaced from and confronting said penetrable wall portion for penetrating said penetrable wall portion of said gas cartridge and releasing pressurized gas from said cartridge;

said device further including means responsive to pressurized gas released from said gas pressure cartridge for applying force to said liquid medication to eject said medication via said jet injection orifice;

said device further including means for selectively moving said gas pressure cartridge axially and impaling said gas pressure cartridge at said penetrable wall portion upon said penetrator in response to a singular user input so as to release pressurized gas from said gas pressure cartridge and to eject said medication via said jet injection orifice to effect a hypodermic jet injection.