System and method for safety syringe
A system for serially injecting liquids includes a syringe body defining a syringe proximal opening and a distal needle interface, proximal and distal stopper members, forming proximal and distal chambers. The system also includes a first liquid in the distal chamber and a second liquid in the proximal chamber, and a plunger configured to be manually manipulated to insert the proximal stopper member distally. Moreover, the system includes a needle hub assembly coupled to the syringe body, the needle assembly including a needle. The needle defines a needle interior, and distal, middle and proximal openings. The distal, middle and proximal openings are fluidly coupled through the needle interior. Manipulating the plunger member to insert the proximal stopper member initially expels the first liquid from the distal chamber, then serially expels the second liquid from the proximal chamber.
1 . 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.
2 . The system of claim 1 , wherein the solid and monolithic proximal end feature is coupled to the tubular member with a weld.
3 . The system of claim 2 , wherein the weld is a fillet weld configured to reduce cutting of the proximal stopper member when the needle penetrates the proximal stopper member compared to a needle without a fillet weld.
4 . The system of claim 2 , wherein the weld tapers in a proximal direction.
5 . The system of claim 2 , wherein the middle opening is adjacent to the weld.
6 . The system of claim 1 , wherein the solid and monolithic proximal end feature is cold formed.
7 . The system of claim 1 , wherein a distal end of the solid and monolithic proximal end feature is disposed in a proximal end of the tubular member.
8 . The system of claim 1 , wherein the middle opening has a rounded edge configured to reduce cutting of the proximal stopper member when the needle penetrates the proximal stopper member compared to a needle without a rounded edge.
9 . The system of claim 1 , wherein the middle opening is an elongated slot.
10 . The system of claim 9 , wherein a length of the elongated slot provides a tolerance for a variability relating to the proximal and distal stopper members.
11 . The system of claim 10 , wherein the variability relating to the proximal and distal stopper members is selected from a group consisting of distortion of a proximal surface of the distal stopper member, a position of the proximal stopper member relative to the elongated slot, and a position of the distal stopper member relative to the elongated slot.
12 . The system of claim 10 , wherein the length of the elongated slot is between about 1/32 inch to about 1/16 inch.
13 . The system of claim 9 , wherein a distance between the elongated slot and the solid and monolithic proximal end feature minimizes retrograde leaking of the first and second liquids into the plunger.
14 . The system of claim 9 , wherein the elongated slot is formed using a grinding wheel.
15 . The system of claim 1 , wherein first and second sizes of the respective distal and proximal chambers can be modified by movement of the proximal and distal stopper members relative to the syringe body.
16 . The system of claim 1 , wherein the plunger member comprises:
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,
wherein the needle hub assembly comprises:
a hub; and
a needle holding member configured to couple the needle to the hub
wherein the needle is at least partially retractable into plunger interior upon manipulation of the plunger member relative to the syringe body to transform the energy-storage member latching member from a latched state to an unlatched state.
17 . The system of claim 16 , wherein the needle is configured to pierce entirely through at least the distal stopper member to be retracted at least partially into the plunger interior.
18 . The system of claim 16 , wherein the energy-storage member latching member is configured to transform from the latched state to the unlatched state at least partially retracting the needle into plunger interior after the second liquid has been expelled from the proximal chamber through the needle.
19 . The system of claim 16 , wherein the needle retention feature is configured to actuate transformation of the energy-storage member latching member from the latched state to the unlatched state upon manipulation of the plunger member to insert the proximal stopper member to the distal end of the syringe body.
20 . The system of claim 1 , the proximal and distal stopper members comprising respective first and second polymer coatings on respective distal and proximal surfaces thereof, such that the proximal chamber is defined by the syringe body and the first and second polymer coatings.
21 . The system of claim 1 , the distal stopper member having
a funnel that tapers in a proximal direction, and
a space disposed at a tapered proximal end of the funnel.
22 . The system of claim 1 , wherein the middle opening is adjacent the distal end of the syringe body.