Patent ID: 8187224

Claim:
A method performed during operation of a medicine injection apparatus, comprising: selecting a medicine injector having: a tube including a barrel and a nose cap attached thereto; a receiving cavity within the tube; a syringe subassembly within the receiving cavity, the syringe subassembly including a reservoir, an injection needle, a hub between the reservoir and the injection needle, and a resilient cushion on the hub; a driver adjacent one end within the tube; and a penetration controller adjacent another end within the tube opposite the one end, the penetration controller including a control sleeve that is removable from the tube and a return spring within the control sleeve radially between the control sleeve and a part of the syringe subassembly; the control sleeve having an abutment surface at one end, another end opposite the one end, and an inside diameter; the return spring having an enlarged portion with an outside diameter greater than the inside diameter of the control sleeve; the enlarged portion of the return spring being retained between the other end of the control sleeve and the nose cap; and the resilient cushion being located axially between the abutment surface and at least a part of the hub; driving the syringe subassembly toward extension of the injection needle from the barrel, the syringe subassembly contacting the abutment surface; absorbing energy of the syringe subassembly and stopping the needle at a desired position using the control sleeve and the return spring; and absorbing energy of the syringe subassembly in the resilient cushion.