US 5,312,335 A · Needleless hypodermic injection device

Abstract

A needleless injection device has a housing containing a pilot valve connectable to a compressed gas source. A two stage power amplifying valve includes a main valve operatively connected to the pilot valve. The pilot valve and main valve form a two-stage valve with the pilot valve activatable to open the main valve utilizing gas pressure. Compressed gas in a reservoir flows through the open main valve to drive a plunger into an ampule to inject an injectant through a patient's skin. Interlocks are provided to resist inadvertent actuation of the device and a indicator indicates whether there is sufficient gas pressure in the device for another injection. An ampule for needleless injection has a nozzle length to nozzle diameter ratio of from 2.0 to 5.0 and a throat cone flair angle of from 10-14 degrees.

Claims11

Dependent claims

A needleless injection system comprising:

a needleless injection device;
an ampule having:
an ampule body containing an injectant chamber;
a tubular shroud attached to the ampule body;
a nozzle section attached to the ampule body concentric with the shroud, the nozzle section having a nozzle opening leading into the injectant chamber;
a Luer fitting on the nozzle section and substantially within the shroud, the Luer fitting having a minimum diameter of approximately 0.15 inch adjacent to the nozzle opening and tapering linearly outwardly to larger diameters towards the injectant chamber;
a plunger slidably displaceable into the injectant chamber;
and
means for attaching the ampule to the injection device.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application

07/714,892Filed 13 Jun 1991 · continuation in part

Priority

9 Nov 1989

Granted

17 May 1994

Term ends

Not estimatedThe source records don’t support an estimate.

Classification10 codes

A61M 5/24
Syringes: ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or cartridges, e.g. automatic
A61M 5/30
Syringes: syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
A61M 5/2053
Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically: media being expelled from…
A61M 5/3007
Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules: with specially designed jet passages at…

Needleless hypodermic injection device

Life of this patent

Needleless hypodermic injection device

Life of this patent

Abstract

Claims11