System and method for safety syringe

A system for serially injecting liquids, comprising:

• a syringe body defining a syringe proximal opening and a distal needle interface at a distal end thereof;
• proximal and distal stopper members disposed in the syringe body, forming a proximal chamber between the proximal and distal stopper members and a distal chamber between the distal stopper member and the distal end of the syringe body;
• a first liquid in the distal chamber;
• a second liquid in the proximal chamber;
• a plunger configured to be manually manipulated to insert the proximal stopper member distally relative to the syringe body;
• and
• a needle hub assembly coupled to the distal needle interface of the syringe body, the needle assembly including a needle,
• wherein the needle defines a needle interior, a distal end opening, a middle opening, and a proximal channel,
• wherein the distal end opening and the middle opening are fluidly coupled through the needle interior,
• wherein manipulating the plunger member to insert the proximal stopper member distally relative to the syringe body initially expels the first liquid from the distal chamber through the needle, then serially expels the second liquid from the proximal chamber through the needle,
• wherein the needle comprises
• a distal portion having a sharp distal tip defining the distal end opening,
• a tubular middle connecting member having middle connecting member proximal and distal ends and defining a portion of the needle interior, and
• a solid and monolithic proximal end feature having a proximal end feature distal end coupled to the middle connecting member proximal end and defining the middle opening with the middle connecting member proximal end,
• wherein the proximal end feature distal end of the solid and monolithic proximal end feature has a crescent or dumbbell shaped cross-section,
• wherein the tubular middle connecting member has a continuous external surface with no side openings along its entire length, and
• wherein a distal end of the solid and monolithic proximal end feature is disposed in an open proximal end of the tubular middle connecting member.