NEEDLELESS HYPODERMIC INJECTION DEVICE

摘要

PATENT 189/230 A needleless injection device has a housing containing pilot valve connectable to a compressed gas source. A two stage power amplifying valve includes a main valve operatively connected 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.