Patent attributes
A system for injecting includes a cartridge body defining a proximal opening and a distal needle interface. The system also includes a plunger member defining a plunger interior and configured to be manually manipulated to insert a stopper member relative to the cartridge body. The plunger member includes a needle retention feature disposed in the plunger interior, an energy-storage member disposed in the plunger interior, and an energy-storage member latching member disposed in the plunger interior. The system further includes a needle hub assembly coupled to the distal needle interface of the cartridge body. The needle assembly includes a needle having a needle proximal end feature, a hub, and a needle latching member configured to couple the needle to the hub. The needle is retractable into plunger interior upon manipulation of the plunger member to actuate the energy-storage member latching member.

