NEEDLELESS HYPODERMIC INJECTION DEVICE

摘要

An improved system for injecting liquid medication into the tissues of a person without using a needle to penetrate the skin includes a power supply mechanism having a source of compressed gas which drives a piston against the plunger of a syringe. The syringe has an aperture which is placed against the skin of a person and through which the liquid medication is ejected with sufficient force to pass through the skin and into the underlying tissues. The syringe is provided with a removable needle assembly so that the syringe can be filled with liquid medication in a conventional manner. The system is constructed so that the needle assembly must be removed in order to insert the needle assembly into the power supply mechanism and is also constructed so that the power supply mechanism cannot be triggered to release the compressed gas unless a syringe is inserted in the power supply mechanism and properly secured.