Polymeric catheter needle tip shielding device

1. A catheter instrument comprising:

a needle comprising a hollow needle shaft and a needle tip;

a needle carrying unit configured to hold the needle therein;

a catheter unit having a proximal end and a distal end defining an axis therebetween, the catheter unit comprising: a catheter hub, the catheter hub having an interface surface, and a catheter, the needle carrying unit adapted to be removably mounted within a proximal end of the catheter hub, with the needle slidable along the axis, to be projected in a distal direction and retracted in a proximal direction;

a needle tip shielding device having a round body adapted to be removably mounted within the catheter hub, the needle tip shielding device including:

a front surface,

a rear surface,

an elevation on at least one of the front and rear surfaces and including a hole positionable along the axis and configured to allow passage of the needle therethrough,

at least one interface surface configured to be removably attached to the interface surface on the catheter hub, and

a self-biased resilient needle tip shielding arm, the needle tip shielding arm including a first arm portion projecting from the front surface of the round body in a direction along the axis,

the first arm having a proximal end attached to the front surface and a distal end, and a second arm portion extending from the distal end of the first arm portion in a direction transverse to the first arm portion, at least a portion of the needle tip shielding arm being made of a first polymeric material; and

a stop member on the needle shaft and configured to prevent the needle tip shielding device from distal movement relative to the needle when the needle is retracted in the proximal direction;

wherein when the needle is projected into the catheter in the distal direction, the self-biased resilient needle tip shielding arm is pushed in a first direction away from the axis by the needle; and

wherein when the needle is retracted in the proximal direction, the self-biased resilient needle tip shielding arm, under the force of its own self-bias and resiliency, moves in the proximal direction, the at least a portion of the needle tip shielding arm made of the first polymeric material shielding the needle tip from subsequent projection in the distal direction,

wherein the interface surface of the needle tip shielding device is made at least partly of the first polymeric material and the interface surface of the catheter hub is made at least partly of a second polymeric material, the second polymeric material being different from the first polymeric material; and

wherein when the needle is fully retracted in the proximal direction to a fully retracted position, the first polymeric material of the interface surface of the needle tip shielding device, and the second polymeric material of the interface surface of the catheter hub, are configured to facilitate removal of at least the needle tip shielding device from the catheter hub.

2. A catheter instrument according to claim 1 , wherein the needle tip shielding device is positioned in a catheter hub annular space in a ready position.

3. A catheter instrument according to claim 1 , wherein at least one of the needle tip shielding device and the catheter hub comprises a protuberance for detachably engaging and forming an imprint in the other of the at least one of the needle tip shielding device and the catheter hub.

4. A catheter instrument according to claim 1 , wherein the stop member comprises an expansion region on the needle near the needle tip for engagement with the needle tip shielding device or the needle carrying unit, thereby preventing distal movement of the needle tip shielding device relative to the needle.

5. A catheter instrument according to claim 1 , wherein the stop member comprises at least one of a friction element, a foldable string, and a stripe having a length less than a length of the needle.

6. A catheter instrument according to claim 1 , wherein the self-biased resilient needle tip shielding arm defines a general L-shaped configuration.

7. A catheter instrument according to claim 1 , wherein the needle tip shielding device further comprises: at least one protuberance.

8. A catheter instrument according to claim 1 , wherein the needle tip shielding device further comprises: at least one slit.

9. A catheter instrument according to claim 1 , wherein an outer surface of the needle tip shielding device is provided with a friction element comprising a rough surface.

10. A catheter instrument according to claim 1 , wherein the second arm portion of the self-biased resilient needle tip shielding arm joins the first arm portion of the self-biased resilient needle tip shielding arm to define a corner, the corner being configured to receive at least a tip of the needle when the needle is in the fully retracted position.

11. A catheter instrument according to claim 1 , wherein the facilitation of removal results from the different first and second polymeric materials.

12. A catheter instrument comprising:

a hollow needle comprising a needle shaft and a needle tip;

a needle carrying unit configured to support the needle;

a catheter unit having a proximal end and a distal end defining an axis therebetween, the catheter unit comprising a catheter hub, and a catheter, the needle carrying unit and the needle being removably mounted in the catheter hub and movable along the axis in a proximal direction and a distal direction;

a needle tip shielding device having a round body adapted to be removably mounted within the catheter hub, the needle tip shielding device including at least:

a front surface,

a rear surface,

an elevation on at least one of the front and rear surfaces and including an aperture positionable along the axis and configured to allow passage of the needle therethrough, and

a biased needle tip shielding arm including:

a first arm portion having a proximal end and a distal end, the proximal end attached to and projecting from the front surface of the round body in a direction along the axis, and

a second arm portion extending from the distal end of the first arm portion in a direction transverse to the first arm portion, at least a portion of the needle tip shielding arm being made of a first polymeric material; and

a stop member on the needle shaft,

wherein when the needle is in a ready position, with the needle projecting into the catheter, the needle is at least partly disposed in, and slidable within, the needle tip shielding device;

wherein when the needle is in a fully retracted position, in which said needle tip is prepared to be completely withdrawn from said catheter, said needle tip shielding arm made of the first polymeric material shields the needle tip from movement in the distal direction by moving across the axis;

wherein the stop member prevents the needle tip shielding device from distal movement relative to the needle in the fully retracted position;

wherein the needle tip shielding device contacts the catheter hub via at least one interface surface between the needle tip shielding device and the catheter hub, the at least one interface surface being defined by a first interface surface on the needle tip shielding device, and a second interface surface on the catheter hub;

wherein the first interface surface on the needle tip shielding device is made at least partly of the first polymeric material, and the second interface surface on the catheter hub is made at least partly of a second polymeric material, the first polymeric material being different from the second polymeric material; and

wherein when the needle is in the fully retracted position, the first polymeric material of the interface surface of the needle tip shielding device, and the second polymeric material of the interface surface of the catheter hub, are configured to facilitate removal of at least the needle tip shielding device from the catheter hub, the facilitation of removal resulting from the different first and second polymeric materials.