Patent ID: 6428528
Filing Date: 2002-08-06
Classification: A61M

Abstract:
A jet injection device comprising a housing, a retractable injection-assisting needle at a distal end of the injector, a nozzle assembly defining a fluid chamber, having an opening for slidingly receiving at least a portion of the needle and being removably associated with the housing, a plunger movable in the fluid chamber, a trigger assembly, and an energy generating source operatively associated with the trigger assembly so that movement of the trigger assembly activates the energy source to move the plunger in a first direction to expel a fluid from the fluid chamber, said retractable injection-assisting needle comprising:a needle tip located at a distal end of the needle with at least a portion configured and dimensioned to slide through the nozzle assembly opening; a discharge channel within the needle tip and terminating in an orifice through which the fluid is expelled; a body portion to direct fluid towards the discharge channel; a plunger receptor configured and dimensioned to receive at least a portion of the plunger; and a retraction element operatively associated with the needle and disposed substantially within the nozzle assembly; wherein the needle is located within the nozzle assembly in a retracted position prior to activation of the energy source; movement of the plunger in the first direction upon activation of the energy source results in (1) at least a portion of the needle tip extending beyond the nozzle assembly opening to a needle insertion point, and (2) the fluid is expelled through the needle tip and past the needle insertion point to an injection site, the retraction element returns the needle tip to the retracted position after activation of the energy source, the needle insertion point is located at the needle tip and less than about 5 mm from the nozzle assembly opening, and the injection site is substantially remote from the needle tip.