Self-sticking needle assembly and method for insertion into an artery
OwnerSew-Wah Tay, Thomas J. Holmaninventors
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Abstract
The needle assembly of the present invention includes a rigid cannula with a blunt distal end, a needle housed inside the cannula, a hub on the needle for controlling the position of the distal end of the needle with respect to the distal end of the cannula and a stop connected to the cannula for limiting the distance of travel of the distal end of the needle. The preferred embodiment may also include a spring attached to the needle hub. The present invention also encompasses methods of using the needle assembly.
Claims26
A needle assembly comprising:
- a) a rigid cannula with a blunt distal end;
- b) a needle having a sharp distal end housed inside said cannula;
- c) a hub on said needle for controlling the position of the distal end of said needle with respect to the distal end of said cannula;
- and
- d) a stop connected to said cannula, wherein when the distal end of said needle is forced past the distal end of said cannula and into a vessel, said stop limits the distance the distal end of said needle may travel past the distal end of said cannula.
A needle assembly comprising:
- a) a housing with a finger-like projection extending from its mid portion toward its proximal end;
- b) a rigid cannula with a blunt distal end attached to said housing;
- c) an inner hub within said housing with a finger-like projection extending from its mid portion toward its distal end;
- d) a needle molded onto said inner hub, said inner hub assembly placed so that the finger-like projections on the housing and hub engage each other;
- and
- e) a spring encompassing said needle such that the proximal end of said spring rests on the distal end of said inner hub assembly.
A method for inserting a needle through an arterial wall to minimize side sticks and optimize the probability of the needle being inserted at the apex of the artery comprising the steps of:
- a) providing a needle assembly comprising:
- i) a rigid cannula with a blunt distal end;
- and
- ii) a needle housed inside said cannula such that the distal end of said needle does not protrude past the distal end of said cannula when in a retracted position;
- b) advancing said needle assembly into the body in the vicinity of an artery while in said retracted position;
- c) determining the optimal puncture site of the vessel by maneuvering said needle assembly until a maximum pulsatile sensation is detected;
- and
- d) moving said needle within said cannula from said retracted position so that said needle projects past the distal end of said cannula and through the arterial wall.
A method for inserting a needle through a vessel wall to eliminate back sticks comprising the steps of:
- a) providing a needle assembly comprising:
- i) a rigid cannula with a blunt distal end,
- ii) a needle housed inside said cannula such that the distal end of said needle does not protrude past the distal end of said cannula when the needle assembly is in a retracted position, and
- iii) a stop connected to said cannula for limiting the distance of travel of the distal end of said needle;
- b) advancing said needle assembly into the body in the vicinity of the apex of a vessel while in said retracted position;
- and
- c) moving said needle within said cannula from said retracted position so that said needle projects past the distal end of said cannula and through the vessel wall, the stop being positioned such that the needle is prevented from sticking all the way through the vessel.
Dependencies are inferred from the claim text.