Needleless hypodermic injection device
US5312335A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 1991 |
| Grant date | May 17, 1994 |
| Priority date | — |
| Expiry date | Jun 13, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2205/583
- WIPO fieldMedical technology
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.