Method of manufacturing a differentially heat treated catheter guide wire

• US RE36,628 E
• Filed: 10/16/1997
• Issued: 03/28/2000
• Est. Priority Date: 01/07/1987
• Status: Expired due to Term

• Current Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Original Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Inventors: Sagae, Kyuta, Sugiyama, Yoshiaki
• Primary Examiner(s): WYSZOMIERSKI, GEORGE P
• Application Number:
  US08/950,602
• Time in Patent Office: 894 Days
• Field of Search: 148/402, 148/563, 148/564, 148/676, 148/902, 148/537, 604/95, 604/164, 604/170, 604/280, 604/282, 604/525, 604/530, 128/772, 128/657, 128/902
• US Class Current: 148/537
• CPC Class Codes: A61M 2025/09083 having a coil around a core
• CPC Class Codes: A61M 2025/09141 made of shape memory alloys which take a particular shape at a certain temperature
• CPC Class Codes: A61M 25/09 Guide wires

Abstract

A catheter guide wire is provided for guiding a catheter into a body cavity such as a blood vessel. The base material constituting the wire is made of an elastic alloy wire and subjected to a heat treatment such that its flexibility is sequentially increased from its proximal to distal end portions. A thermoplastic resin or/and a coil spring can be applied to at least the distal end portion of the wire base material. A method of manufacturing the catheter guide wire is also provided. The method is characterized in that the leading end side of the base material is divided into a plurality of areas and subjected to a heat treatment by changing the heat treatment temperature and the time conditions in units of the areas so that the flexibility of the base material is sequentially increased from the proximal to distal end portions of the leading end side.

Claims

1. A method of making a catheter guide wire for guiding a catheter, said method comprising:

forming a wire member comprising a superelastic Ni-Ti alloy wire as a base material, said base material having a proximal end portion and a leading end side;

dividing said leading end side of said base material into a plurality of areas along the length thereof and a distal end portion, said plurality of areas comprising an intermediate portion between said proximal and distal end portions; and

subjecting only said intermediate portion and said distal end portion to a primary heat treatment at a temperature of 400°

to 500°

C. for about two hours, and then subjecting only said distal end portion to a secondary heat treatment at a temperature of about 200°

C. for about 24 hours, whereby said proximal end portion is not heat treated after cold rolling, such that said distal end portion, after said primary and secondary heat treatments, has a yield stress of approximately 5 to 7 kg/mm², and at least one of said areas at said intermediate portion, after said heat treatment, has a yield stress of approximately 11 to 12 kg/mm².

2. A method according to claim 1, comprising forming said wire member so as to have a proximal end portion having an outer diameter ranging from 0.2 to 0.4 mm.

3. A method of making a catheter guide wire for guiding a catheter, said method comprising:

forming a wire member comprising a superelastic Ni-Ti alloy wire as a base material, said base material having a proximal end portion and a leading end side;

dividing said leading end side of said base material into a plurality of areas along the length thereof and a distal end portion, said plurality of areas comprising an intermediate portion between said proximal and distal end portions; and

subjecting only said intermediate portion and said distal end portion to a primary heat treatment at a temperature of 400°

to 500°

C. for about two hours, and thereafter subjecting only said distal end portion to a secondary heat treatment at a temperature of about 200°

C. for about 24 hours, whereby said proximal end portion is not heat treated after cold rolling, such that, after said primary and secondary heat treatments, flexibility of the guide wire is increased from said proximal end portion to said distal end portion thereof.

4. A method according to claim 3, comprising forming said wire member so as to have a proximal end portion having an outer diameter ranging from 0.2 to 0.4 mm. .Iadd.

5. A process for forming a guide wire for a catheter, said guide wire having a proximal end and a distal end, comprising:

forming a Ni-Ti alloy wire;

cold rolling said Ni-Ti alloy wire;

forming said distal end portion and said proximal end portion of said guide wire, said distal end portion having a diameter that is less than a diameter of said proximal end portion; and

subsequently heat treating said distal end portion of said guide wire so as to make said distal end portion more flexible than said proximal end portion. .Iaddend..Iadd.6. A process for forming a guide wire for a catheter, said guide wire having a proximal end and a distal end, comprising;

forming a Ni-Ti alloy wire;

cold rolling said Ni-Ti alloy wire;

forming said distal end portion and said proximal end portion of said guide wire, said distal end portion having a diameter that is less than a diameter of said proximal end portion;

subsequently heat treating said distal end portion of said guide wire so as to make said distal end portion more flexible than said proximal end portion; and

forming a thermoplastic resin layer on said guide wire. .Iaddend..Iadd.7. A process for forming a guide wire for a catheter, said guide wire having a proximal end and a distal end, comprising;

forming a Ni-Ti alloy wire;

cold rolling said Ni-Ti alloy wire;

forming said distal end portion and said proximal end portion of said guide wire, said distal end portion having a diameter that is less than a diameter of said proximal end portion;

subsequently heat treating said distal end portion of said guide wire so as to make said distal end portion more flexible than said proximal end portion; and

mounting a coil spring around at least a portion of said guide wire.

6. Iaddend..Iadd.8. A process for forming a guide wire for a catheter, said guide wire having a proximal end and a distal end, comprising:

forming a Ni-Ti alloy wire;

cold rolling said Ni-Ti alloy wire;

forming said distal end portion and said proximal end portion of said guide wire, said distal end portion having a diameter that is less than a diameter of said proximal end portion;

subsequently heat treating said distal end portion of said guide wire so as to make said distal end portion more flexible than said proximal end portion;

forming a thermoplastic resin layer on said guide wire; and

mounting a coil spring around at least a portion of said guide wire. .Iaddend.