Interventional needle having an automatically capping stylet
First Claim
1. An interventional needle apparatus for accessing an internal anatomical region and having a cannula with a tubular shaft and a hub having an opening leading to the shaft thereof and also having a stylet having a shaft and a penetrating tip which, when in working relationship, is disposed inside the tubular shaft and the opening of the hub of the cannula with the point of the tip extending from the tubular shaft and which said stylet is withdrawn from said cannula in the course of a procedure for accessing of said internal anatomical region, the improvement for capping said tip when said stylet is withdrawn which comprises a guard body having a hole, said guard body being slidably disposed on said stylet shaft with said stylet shaft extending through said hole, said guard body having a first surface within said hole engageable with a shoulder surface of said stylet shaft and spaced inwardly in said guard body by a distance sufficient to locate said tip within said guard body when said first and said shoulder surfaces are engaged with each other, said guard body being receivable at least in part in said hub opening, said hub having hub surface and said guard body having a second surface which are engageable with each other and limit the extent to which said guard body is disposed in said hub opening when received therein, a slot in said guard body crossing said hole in said guard body in which said stylet shaft is slidably disposed, an arm in said slot connected to said guard body and having a first portion moveable from a first position in interfering relationship with the movement of said stylet with respect to said cannula and a second position out of said interfering relationship, said hub of said cannula having a cam surface engageable with a cam follower surface on said arm when said guard body enters said hub opening to be received at least in part therein and when said guard body leaves said hub opening for moving said arm between said second and first positions, respectively, thereby automatically capping said stylet tip when said stylet is withdrawn from said cannula.
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Accused Products
Abstract
The tip of a stylet which is received in a needle cannula is automatically capped in a guard body when the stylet is withdrawn from the cannula. The stylet may be reassembled in the cannula and put into working position, with the point of the tip extending from the cannula shaft, by reinserting the stylet and guard into the cannula hub. The guard contains an arm which moves into blocking position with respect to the tip of the stylet when it is withdrawn from the cannula by following a cam surface on the cannula hub (either inside or outside the hub for different styles of needle cannulas). The arm may be spring biased, across a hole in the guard in which the stylet is slidably disposed into interfering relationship with the arm. The cam surface urges the arm to bring a portion thereof which protects the point of the tip of the stylet and captures it inside the guard. The arm and cam prevent removal of the stylet from the cannula until the tip is covered and protected by the guard, thereby automatically capping the tip of the stylet to prevent potentially dangerous, inadvertent, or accidental sticking of medical personnel. The interventional needle apparatus may be used as an angiographic needle and for other purposes, wherever access to vessels, kidneys or other body parts as for the insertion of catheters, infusions or drainage of body fluids including spinal fluid is required or where tissue is obtained by needle biopsy.
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Citations
18 Claims
- 1. An interventional needle apparatus for accessing an internal anatomical region and having a cannula with a tubular shaft and a hub having an opening leading to the shaft thereof and also having a stylet having a shaft and a penetrating tip which, when in working relationship, is disposed inside the tubular shaft and the opening of the hub of the cannula with the point of the tip extending from the tubular shaft and which said stylet is withdrawn from said cannula in the course of a procedure for accessing of said internal anatomical region, the improvement for capping said tip when said stylet is withdrawn which comprises a guard body having a hole, said guard body being slidably disposed on said stylet shaft with said stylet shaft extending through said hole, said guard body having a first surface within said hole engageable with a shoulder surface of said stylet shaft and spaced inwardly in said guard body by a distance sufficient to locate said tip within said guard body when said first and said shoulder surfaces are engaged with each other, said guard body being receivable at least in part in said hub opening, said hub having hub surface and said guard body having a second surface which are engageable with each other and limit the extent to which said guard body is disposed in said hub opening when received therein, a slot in said guard body crossing said hole in said guard body in which said stylet shaft is slidably disposed, an arm in said slot connected to said guard body and having a first portion moveable from a first position in interfering relationship with the movement of said stylet with respect to said cannula and a second position out of said interfering relationship, said hub of said cannula having a cam surface engageable with a cam follower surface on said arm when said guard body enters said hub opening to be received at least in part therein and when said guard body leaves said hub opening for moving said arm between said second and first positions, respectively, thereby automatically capping said stylet tip when said stylet is withdrawn from said cannula.
Specification