Safe injection systems and methods

A system for injection, comprising:

• a syringe body having proximal and distal ends and defining a syringe interior;
• a stopper member disposed in the syringe interior;
• a needle hub assembly coupled to the syringe body at the distal end thereof and comprising
• a needle hub, and
• a needle coupled to the needle hub and having a needle proximal end;
• a plunger member coupled to the stopper member and configured to be manipulated to insert the stopper member distally in the syringe interior relative to the syringe body and the needle hub,
• wherein the plunger member comprises
• a plunger body defining a plunger interior,
• a retraction member disposed in the plunger interior and configured to couple to the needle proximal end, and
• a spring disposed in the plunger interior and configured to withdraw the retraction member proximally in the plunger interior, the spring having a compressed state and a released state, and
• wherein the retraction member comprises
• a catch-latch having
• a plurality of distal arms configured to interfere with the needle proximal end, and
• a plurality of spring latches configured to hold the spring in the compressed state, and
• a trigger movably disposed in the catch-latch along a longitudinal axis thereof and defining
• a proximal radial extension,
• a distal radial extension, and
• an annular trough between the proximal and distal radial extensions.