Kinetic memory electrodes, catheters and cannulae

• US 3,890,977 A
• Filed: 03/01/1974
• Issued: 06/24/1975
• Est. Priority Date: 03/01/1974
• Status: Expired due to Term

• Current Assignee: Bruce C. Wilson
• Original Assignee: Bruce C. Wilson
• Inventors: Wilson, Bruce C.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Cohen, Lee S.
• Application Number:
  US05/447,340
• Time in Patent Office: 480 Days
• Field of Search: 128/418,419P,404,2.5R,2.6E,2.1E,348,349R,35R,351,DIG.4 3/1.7 75/170,175.5
• US Class Current: 604/531
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/29 for permanent or long-term implantation
• CPC Class Codes: A61B 5/6855 with a distal curved tip
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2210/0023 operated at different temperatures whilst inside or touching the human body, heated or cooled by external energy source or cold supply
• CPC Class Codes: A61F 2210/0033 electrically, e.g. heated by resistor
• CPC Class Codes: A61F 2210/0047 heated by light
• CPC Class Codes: A61M 2025/0163 Looped catheters
• CPC Class Codes: A61M 25/0158 with magnetic or electrical means, e.g. by using piezo materials, electroactive polymers, magnetic materials or by heating of shape memory materials
• CPC Class Codes: A61M 25/04 in the body, e.g. expansible A61M25/10, A61M16/0488 take precedence
• CPC Class Codes: A61N 1/057 Anchoring means; Means for fixing the head inside the heart

Abstract

A conductive electrode-catheter, biological catheter cannula or the like which is easily inserted into the body and which is effectively anchored into a desired organ or tissue or properly located within a target cavity. The electrode, catheter, or the like incorporates a material, such as a known titanium-nickel alloy, having heat-activated mechanical memory. The device is formed and annealed at high temperature into a shape for effective anchoring or proper location in an organ or other structure of the body. Then at a temperature below its transitional temperature it is reformed into a shape for ease of insertion, and when located in the desired organ or structure is heated above its transitional temperature, thereby returning to its original annealed anchoring or proper locating shape.

Claims

1. A catheter comprising a. an elongated generally cylindrical body member having a proximate and a distal end, said distal end for insertion into a body, b. a distal portion of said body member capable of assuming a shape for ready insertion into a body, and a different shape for proper location in a body, and c. means for shifting said distal portion from said readily insertable shape to said different properly locating shape upon bringing said portion to a specified temperature, said means comprising at least a portion of transitional temperature activated mechanical memory material formed into said distal portion.

2. A catheter as recited in claim 1 wherein said body member is formed of flexible non-conductive material having at least one section of conductive material formed on the exterior of a distal portion thereof and an interior section of conductive material leading from said exterior conductive material section to the proximate end of said body member, whereby the catheter functions as an electrodecatheter.

3. A catheter as recited in claim 2 wherein said interior of conductive material is hollow, and wherein said portion of transitional temperature activated mechanical memory material comprises a rod encompassed by said section of hollow conductive material.

4. A catheter as recited in claim 2 wherein said interior section of conductive material comprises in part said transitional temperature activated mechanical memory material.

5. A catheter as recited in claim 1 wherein said body member is formed of flexible non-conductive material and has an internal cavity extending substantially throughout the length thereof, and at least one passage formed in the distal end of the body member communicating from the exterior thereof to said internal cavity.

6. A catheter as recited in claim 5 wherein said portion of transitional temperature activated mechanical memory material is in the form of a braid in engagement with the distal portion of said body member.

7. A catheter as recited in claim 5 wherein said portion of transitional temperature activated mechanical memory material is in the form of a rod.

8. A catheter as recited in claim 1 wherein said shape for ready insertion is a straight shape, and wherein said shape for proper location is a curved shape.

9. A catheter as recited in claim 1 wherein said transitional temperature activated mechanical memory material is an alloy consisting essentially of from 52-56% nickel by weight and correspondingly from about 48-44% titanium by weight.

10. A catheter as recited in claim 1 wherein said transitional temperature activated mechanical memory material is an alloy having the formula TiNixCo1-x wherein Ti denotes titanium and constitutes approximately 50 atomic percent of the composition and the term NixCo1-x denotes nickel and cobalt respectively and make up the remaining approximately 50 atomic percent of the composition, and x is a factor which varies from greater than 0 to less than 1 whereby the relative percentage of nickel and cobalt varies inversely from less than 100 percent to more than 0 percent with respect to each other on an atom for atom exchange basis.

11. The method of properly locating a catheter in a body structure within a body comprising the steps of a. forming a member of transitional temperature activated mechanical memory material into a first shape, b. incorporating said member into a portion of a catheter, c. forming said catheter portion into a second shape for ease of insertion into the body and advancement of said catheter to the body structure, d. inserting the catheter into the body and advancing said catheter to the body structure, e. heating said catheter portion to a specified temperature whereby said catheter portion will revert to said first shape and will thereby assume a shape for proper location of the catheter within the body structure.

12. The method of claim 11 comprising the further step of immersing said portion of the catheter into a cooling fluid until the catheter has been inserted into the body and advanced to the body structure.

13. The method of claim 11 wherein said heating is accomplished by passing an electrical curreNt through said transitional temperature activated mechanical memory material member of the catheter.

14. The method of claim 11 wherein said heating is accomplished by immersing said portion of the catheter into a heating fluid.

15. The method as recited in claim 11 wherein said specified temperature is body temperature or slightly less than body temperature, and wherein the body accomplishes said heating.