| 摘要 |
<p>A needleless injector has an injection nozzle (17) surrounded by a sleeve (14) to stabilize the nozzle (17) against tissue to be injected. Vacuum can be applied to the space within the sleeve (14) outside the nozzle (17). Medicament (16) is injected by means of a plunger (12) and a piston rod (25) of a piston and cylinder (20,23) to which a charge of compressed gas can be delivered. An interlock (24) allows delivery of such gas only if the vacuum in the sleeve (14) as sensed by a vacuum sensor (8) attains a predetermined value. The gas pressure may be adjusted to control depth of penetration of the injected medicament and the stroke length of the rod 25 may be adjusted (at 26) to control the volume of medicament injected.</p> |
