Patent ID: 7637891

Claim:
A self-contained device for painless, intramuscular injection of a liquid medicament, comprising: a) a housing having a base for attachment to the skin of a patient, b) an injection needle disposed substantially perpendicular to the base and within the housing, the needle having an outside diameter less than about 0.38 mm, an inlet end and an opposed injection end, and being configured for axial movement between a first position wherein the injection end is within the housing and a second position wherein the injection end extends outwardly from the base, c) a reservoir containing a liquid medicament, d) a means for liquid communication between the reservoir and the injection needle, e) a means for inserting the injection needle to its second position, f) a means for pumping the medicament from the reservoir to the injection end of the injection needle at a substantially constant volumetric flow rate of from about 0.5 μL/s to about 20 μL/s.