Small gauge, pre-split cannula and process for manufacture
First Claim
1. A cannula needle for insertion of a catheter therethrough, comprising:
- A. A cannula including;
a barrel portion having a longitudinal axis, distal and proximal ends, and internal and external walls;
i. one or more weakening grooves formed along the internal wall and parallel to the longitudinal axis;
ii. the barrel portion being produced by the sequential steps of grooving flatstock having parallel edges, and a thickness of about 2-8 mils, rolling the flatstock to form the barrel, and reducing the barrel in diameter to form a 14-36 gauge barrel diameter of continuous shape, closed, registered edges, and closed grooves in the internal wall, a cannula length of about 3/4"-6", and a uniform groove depth of about 30%-60% of the flatstock thickness using a 304-316 stainless steel, the barrel being work hardened, and the grooves and enclosed edges being embrittled by rolling and cold drawing;
iii. pre-split proximal ends and a needle portion being formed on the barrel; and
,B. separable wing holders, including a reinforcing barrel surrounding the proximal end of the cannula, a pre-split end being mounted within a separate wing;
whereby,i. during use, the cannula is adapted for minimal leakage of blood through the closed edges and grooves and for aspiration of blood through the cannula; and
, ii. following use, the cannula is adapted to be split open, commencing from the proximal ends and continuing along the grooves, thereby enabling the cannula to be separated from the catheter, the wing holders being adapted to secure each pre-split end of the cannula when being split open.
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Accused Products
Abstract
A small size cannula having internal grooves is produced by pre-splitting the proximal end of the cannula along the grooves, and mounting the split ends into plastic, breakaway wings. By means of the split ends, mounting of the cannula into the wings is greatly facilitated. The process also permits the grooves to be formed along the barrel of the cannula in a random fashion, which entails less manufacturing expense.
Following insertion of the cannula into a patient, the catheter is fed through the cannula into the patient, and the cannula is withdrawn. The pre-split cannula is then broken or split away from the catheter using the wings. Since less force is required to initiate splitting of the cannula, shallower grooves can be used, and this results in a greater structural integrity for cannula of smaller sizes.
105 Citations
11 Claims
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1. A cannula needle for insertion of a catheter therethrough, comprising:
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A. A cannula including;
a barrel portion having a longitudinal axis, distal and proximal ends, and internal and external walls;i. one or more weakening grooves formed along the internal wall and parallel to the longitudinal axis; ii. the barrel portion being produced by the sequential steps of grooving flatstock having parallel edges, and a thickness of about 2-8 mils, rolling the flatstock to form the barrel, and reducing the barrel in diameter to form a 14-36 gauge barrel diameter of continuous shape, closed, registered edges, and closed grooves in the internal wall, a cannula length of about 3/4"-6", and a uniform groove depth of about 30%-60% of the flatstock thickness using a 304-316 stainless steel, the barrel being work hardened, and the grooves and enclosed edges being embrittled by rolling and cold drawing; iii. pre-split proximal ends and a needle portion being formed on the barrel; and
,B. separable wing holders, including a reinforcing barrel surrounding the proximal end of the cannula, a pre-split end being mounted within a separate wing;
whereby,i. during use, the cannula is adapted for minimal leakage of blood through the closed edges and grooves and for aspiration of blood through the cannula; and
, ii. following use, the cannula is adapted to be split open, commencing from the proximal ends and continuing along the grooves, thereby enabling the cannula to be separated from the catheter, the wing holders being adapted to secure each pre-split end of the cannula when being split open. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification