Patent ID: 6932789

Claim:
A method of injecting a liquid into tissue comprising the steps of: (a) providing a hand-held, needle-less injector, the needle-less injector including, a housing including at least two portions rotatable relative to each other, a cylinder disposed within said housing, a locking stressing mechanism disposed within said housing, said locking stressing mechanism including, a sprung portion, and a hollow plunger having a first end and a second end, said hollow plunger being fixed to said sprung portion, wherein said hollow plunger slidably extends within said cylinder, and wherein said hollow plunger includes a valve body disposed at said first end of said hollow plunger, a nozzle having at least one opening, said nozzle being fixed to said cylinder such that said nozzle, said cylinder and said valve body form a pump chamber therebetween, and a removable supply container disposed within said housing, said supply container being connected around said second end of said hollow plunger, wherein an amount of a liquid conveyed from said supply container, through said hollow plunger into said pump chamber is determined by a stroke travel distance and a cross-section of said hollow plunger; (b) pressing the needle-less injector against the tissue at an injection location; and (c) activating the needle-less injector such that the liquid is injected at a force sufficient to penetrate the tissue.