Blown-in-place blood gasket for a safety catheter
AssigneeJohnson & Johnson Medical, Inc.
InventorsDavid L. Bogert, Andrew Brockway, David Goral
Life of this patent
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Abstract
An intravenous catheter insertion devices, and in particular an extruded plastic blood sealing gasket for a blood chamber of the safety catheter. A cannula extends through the blood gasket with the assurance of a seal being present therebetween during relative sliding movement between the cannula and the blood gasket. Moreover, disclosed is a method of forming a blown-in-place extruded plastic gasket for a safety catheter adapted to slidingly receiving a cannula in sealing engagement therewith in a simple and inexpensively produced manner.
Claims18
A method of producing a blood sealing gasket for a safety catheter, wherein said safety catheter includes a nose portion having an elongate cannula axially slidably positioned therein, said cannula having a first end protruding from said nose portion fixedly connected with a chamber structure for receiving blood from a patient and including a second end extending from an opposite end of said nose portion for insertion into a vein of the patient;
- said method comprising:
- (a) positioning an extruded hollow cylindrical plastic member in a central bore axially extending through said nose portion;
- (b) extending said cannula through an axial bore in said hollow cylindrical plastic member, said axial bore of said hollow cylindrical plastic member for receiving said cannula being dimensioned so as to provide an annular space about said cannula;
- (c) imparting heat to said cannula to cause the material of the inner surface of the axial bore of said hollow cylindrical plastic member to foam and expand radially inwardly to sealingly engage the outer surface of said cannula;
- (d) and imparting axial reciprocating movement to said cannula within said foamed bore surface of the cylindrical member to inhibit binding between the cannula and said hollow cylindrical plastic member enabling axial displacement of said cannula relative to said nose portion while maintaining sealing contact with said hollow cylindrical plastic member such that the latter forms said blood sealing gasket.
A safety catheter and blood sealing gasket, wherein said safety catheter includes a nose portion having an elongate cannula axially slidably positioned therein, said cannula having a first end protruding from said nose portion and fixedly connected with a chamber structure for receiving blood from a patient and including a second end extending from an opposite end of said nose portion for insertion into a vein of the patient;
- comprising
- (a) an extruded hollow cylindrical plastic member being positioned in a central bore axially extending through said nose portion;
- (b) said cannula extending through an axial bore in said hollow cylindrical member, said axial bore in said hollow cylindrical plastic member for receiving said cannula being initially dimensioned so as to provide an annular pace about said cannula said cannula further being coated with a release agent means comprising silicone to prevent adherence to said hollow cylindrical plastic member;
- (c) said cannula being subjected to heat such as that the material of the inner surface of the axial bore of said hollow cylindrical plastic member is foamed and expanded radially inwardly to sealingly engage the outer surface of said cannula;
- whereby said cannula is axially reciprocated within said foamed bore surface of said hollow cylindrical plastic member to inhibit binding between the cannula and cylindrical member enabling axial displacement of said cannula relative to said nose portion while maintaining sealing contact with said hollow cylindrical plastic member such that the latter forms said blood sealing gasket.
Dependencies are inferred from the claim text.