Patent ID: 9629960
Date: 2017-04-25
CPC Classifications: A61M

Claim:
1. A needle-free injector for injecting through skin, comprising: a piston housed within a syringe body; a power source for applying an initial force to a ram to initiate delivery of a liquid and collapse of a bubble in the liquid; wherein during a first stage of delivery, a reduced force is applied by the ram to a piston which applies force to the liquid in the first stage of delivery thereby causing the bubble to collapse in a slow, controlled manner; and further wherein during a second stage of the delivery, the ram and piston are configured in the needle-free injector so as to transfer energy of the ram to the piston wherein the piston applies force to the liquid in the second stage; wherein pressure in the liquid during the second stage is sufficiently high to enable an initial pulse of liquid to penetrate skin.