Needleless hypodermic injection methods and device

• US 5,520,639 A
• Filed: 03/21/1995
• Issued: 05/28/1996
• Est. Priority Date: 07/24/1992
• Status: Expired due to Term

• Current Assignee: Bioject Incorporated
• Original Assignee: Bioject Incorporated
• Inventors: McKinnon, Charles N. Jr., Smith, Paul E., Nakagawa, Takaaki, Bartholomew, Victor L., Peterson, Steven F.
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): VANOVER, PERRY
• Application Number:
  US08/407,867
• Time in Patent Office: 434 Days
• Field of Search: 604/68-72, 604/147, 604/140-143, 604/187, 604/228, 604/232, 222/389
• US Class Current: 604/68
• CPC Class Codes: A61M 2005/31516 reducing dead-space in the syringe barrel after delivery
• CPC Class Codes: A61M 2205/583 by visual feedback
• 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 5/30 Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules

Abstract

A needleless injection device includes an initiator valve controlling flow of compressed gas into a reservoir. A poppet valve connecting to the reservoir has a gas pressure regulation end to regulate flow from the initiator valve into the reservoir. A clamp piston is driven forward by gas pressure from the reservoir and causes jaws to clamp onto a plunger extending into an ampule. The poppet valve opens when reservoir pressure reaches the cracking pressure of the poppet valve. Gas from the reservoir rushes through the poppet valve into a drive chamber and forces a drive piston, containing the clamp piston and jaws, forward causing the plunger to slide into the ampule. A jet of injectant is discharged from the nozzle of the ampule and penetrates through the patient'"'"'s skin. An improved method of needleless injection uses a specific pressure profile, ampule nozzle diameter, patient, injection site, and injectant parameters.

Claims

1. A device for driving a plunger into an ampule to provide a jet injection comprising:

a housing;

a driver piston slidably contained within said housing; and

a clamp piston slidably positioned within said driver piston for linking said driver piston to the plunger regardless of plunger location.

2. The injection device of claim 1 further comprising a valve within said housing and means for mechanically linking said clamp piston to the plunger, controlled by the valve.

3. The device of claim 1 further comprising lugs on the ampule and said housing, for attaching the ampule to said housing.

4. The device of claim 1 further comprising clamp jaws adapted to engage a ramp drive on the clamp piston.

5. The injection device of claim 4 further comprising clamp jaw biasing means for biasing the clamp jaws apart.

6. A jet injection device, comprising:

a housing;

a driver piston contained with said housing;

an ampule releasably attached to said housing;

a plunger extending from said ampule at least partially into said housing; and

a clamp piston within said driver piston for engaging onto said plunger, regardless of the position of said plunger within said housing.

7. A jet injection device comprising:

a housing;

a compressed gas source within said housing;

a driver slidably contained within said housing;

means for linking said driver to an ampule plunger, actuated by compressed gas; and

a release valve within said housing for releasing compressed gas to actuate said means for linking.

8. The device of claim 7 further comprising an initiator valve for releasing compressed gas from said compressed gas source into a reservoir within the housing.

9. The device of claim 8 further comprising a regulation valve associated with said release valve, for regulating compressed gas flow into the reservoir.