CATHETER PLACEMENT DEVICE AND METHOD

• US 3,633,579 A
• Filed: 03/13/1969
• Issued: 01/11/1972
• Est. Priority Date: 05/24/1967
• Status: Expired due to Term

• Current Assignee: Sherwood Medical Company (Medtronic Plc)
• Original Assignee: David S. Sheridan, Ralph D. Alley
• Inventors: Alley, Ralph D., Sheridan, David S.
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US04/843,866
• Time in Patent Office: 1,034 Days
• Field of Search: 128/2.05,214.4,221,348,DIG.16
• US Class Current: 604/508
• CPC Class Codes: A61M 25/0662 Guide tubes

Abstract

A medical device for use in intravenous or intraarterial injections of fluids, in blood sampling, in diagnostic procedures such as intravascular blood sampling including sampling in the heart, and in intravascular pressure measurements using transducers. The device incorporates a novel catheter means and method for placing a flexible cannula in a vein or artery such that the catheter means can be threaded through the cannula into the vein or artery of a patient an appropriate distance. The catheter can be secured in position relative to the cannula by means of a self-contained locking arrangement carried by the catheter. In preferred forms, the locking force against the catheter can be distributed over an area to assure a good lock without restricting the catheter and without the expense of providing close tolerance in the locking system.

Claims

1. In a catheter placement device comprising a flexible plastic cannula, an elongate catheter threaded into said cannula, said cannula having a tapered distal end portion and a flared proximal end portion and locking means comprising a ferrule slidably carried on said catheter for locking said catheter relative to said cannula when said catheter is in position in said cannula, said ferrule having a tapered outer wall and a continuous inner wall, the distal end of said ferrule engaging with the inner surface of the tapered distal end portion of the cannula for creating the locking action against the outer surface of said catheter.

2. A device as claimed in claim 1 wherein said catheter is made of a plastic material and has an X-ray opaque line extending from the distal end through at least a portion of said catheter.

3. A device as claimed in claim 1 wherein said cAtheter is made of an X-ray opaque material.

4. A device as claimed in claim 1 wherein means are provided on the proximal end of said catheter for attaching said catheter to another instrument.

5. The device of claim 1 wherein at least the distal end portion of said ferrule is flexible.

6. The device of claim 1 wherein said locking action comprises means for distributing the force against the catheter over a portion of the length of said catheter.

7. The device of claim 6 wherein the force spreading means comprises a frustoconical end on said ferrule engaging said catheter.

8. The device of claim 6 wherein the force spreading means comprises slit means in the wall of said ferrule extending axially from the catheter engaging end thereof.

9. In a catheter placement device comprising a flexible plastic cannula, an elongate catheter threaded into said cannula, said cannula having an enlarged proximal end portion with a tapered inner wall surface therein, locking ferrule means slidably carried on said catheter in a position proximally located with respect to said enlarged end of said cannula, said ferrule having an outer wall surface tapered downwardly toward the distal end thereof, said distal end of said ferrule being wedged between the inner tapered wall of said cannula and the outer surface of said catheter for locking said catheter relative to said cannula.

10. A method of placing a catheter in a patient comprising the steps of inserting a cannula shrouded needle into a body cavity of a patient, withdrawing the needle from the cannula and leaving the cannula in position in the patient, sliding a locking ferrule that surrounds an elongate thin flexible catheter toward the proximal end of said catheter so as to expose a length of catheter forward of said ferrule, threading said catheter through said cannula into position in said patient, and locking said catheter relative to said cannula by wedging said ferrule between said cannula and the outer surface of said catheter.

11. In a catheter placement device comprising a flexible plastic cannula, an elongate catheter threaded into said cannula, said cannula having an enlarged proximal end portion with a tapered inner wall surface therein, and locking means comprising a ferrule slidably carried on said catheter for locking said catheter relative to said cannula when said catheter is in position in said cannula, said ferrule having a tapered outer wall and a continuous inner wall, the distal end of said ferrule being wedged between the inner tapered wall of said cannula and the outer surface of said catheter for locking said catheter relative to said cannula.

12. A method of placing and securing a catheter in a patient comprising the steps of inserting a cannula shrouded needle into a vein or artery of a patient, withdrawing the needle from the cannula and leaving the cannula in position in the patient, positioning a locking ferrule over the distal end of the catheter with the locking end of said ferrule pointed toward said distal end, sliding said ferrule toward the proximal end of said catheter, threading the distal end of said catheter through said cannula into position in said patient, and locking said catheter relative to said cannula by wedging said distal end of said ferrule between said cannula and the outer surface of said catheter.