Patent ID: 6565553
Filing Date: 2003-05-20
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 and having an opening for allowing at least a portion of the needle to pass therethrough, with the nozzle assembly being removably associated with the housing; a plunger movable in the fluid chamber; a trigger assembly; and a force generating source operatively associated with the trigger assembly such that movement of the trigger assembly activates the force generating source to move the plunger in a first direction to expel a fluid from the fluid chamber; with the 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 move 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 force generating source; movement of the plunger in the first direction upon activation of the force generating source results in extension of at least a portion of the needle tip beyond the nozzle assembly opening to a needle insertion point, with the retraction element returning the needle tip to the retracted position after activation of the force generating source; the needle tip, when extended, has a length sufficient to puncture the epidermis of a patient so that the fluid is delivered to an injection site that is substantially remote from the needle tip.