Intradermal injection device

Abstract

Embodiments herein relate to the field of injections, for instance needle-free injections, and more specifically, to methods and apparatus for spring-driven intramuscular and intradermal injections. Provided in some embodiments are needle-free injectors adapted to deliver intradermal injections, as well as vial adaptors that are adapted to function as spacers when used with a needle-free injection device.

1 .- 19 . (canceled) 
     
     
         20 . A needle-free injection device, comprising:
 a body terminating in a nozzle;   a fluid reservoir housed within the body, the fluid reservoir being adapted to receive a fluid injectate;   a plunger disposed within the fluid reservoir;   a shaft to which the plunger is mounted such that when the shaft is driven forward, the plunger is responsively driven forward;   a spring-driven propulsion system having a first spring adapted to apply force to the shaft and thus to the plunger to cause ejection of the fluid injectate through the nozzle;   a lever adapted to arm the spring-driven propulsion system;   a rod extending between the lever and the shaft to transmit force between the lever and the shaft via the body of the rod to compress the first spring; and   a second spring in operable communication with the lever, the second spring configured to bias the lever towards a home position.