Don't mention it. [he kneels down in front of the healing unit and leans forward on his thigh to apply pressure until his HUD tells him he's out of the danger zone. his rifle and the envelope are set down beside him. he's very grateful it wasn't another injury to his back.]

Yeah, these healing units were developed recently. [though "recently" is a term he uses rather loosely] Give your world time, and they'll probably come up with something similar.