Spring-biased tip assembly

• US 5,114,402 A
• Filed: 03/05/1991
• Issued: 05/19/1992
• Est. Priority Date: 10/31/1983
• Status: Expired due to Term

• Current Assignee: Catheter Research Incorporated
• Original Assignee: Catheter Research Incorporated
• Inventors: McCoy, William C.
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/664,527
• Time in Patent Office: 441 Days
• Field of Search: 604/95, 604/164, 604/170, 604/264, 604/280-282, 128/6, 128/4, 128/657, 128/772
• US Class Current: 604/95.05
• CPC Class Codes: A61B 1/0051 with controlled bending of insertion part
• 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: C08L 2201/12 Shape memory

Abstract

A maneuverable distal apparatus includes a temperature-activated memory element moving in a first direction to assume a predetermined shape when heated to a predetermined temperature and control means for selectively heating the memory element so that the memory element is moved in the first direction. A spring is provided for yieldably urging the memory element in a second direction away from the first direction upon cooling of the memory element to a temperature less than the predetermined temperature so that the memory element is moved to assume a shape other than the predetermined shape.

Claims

1. An apparatus comprising

an elongated tubular member having a proximal end and a flexible distal end for insertion into a body,

resilient means for applying a predetermined biasing force to move the flexible distal end of the tubular member to assume a predetermined curved shape, the resilient means being coupled to the distal end of the tubular member and configured to provide the predetermined biasing force, a shape-control element coupled to the distal end, and a control mechanism configured to vary the shape of the shape-control element within the elongated tubular member so that the flexible distal end of the tubular member is moved against the biasing force provided by the resilient means to assume a shape other than its predetermined curved shape.

2. The apparatus of claim 1, wherein the resilient means is made of a spring material preformed to define the predetermined curved shape.

3. An apparatus comprising

an elongated tubular member having a proximal end and a flexible distal end for insertion into a body,

resilient means for applying a predetermined biasing force to move the flexible distal end of the tubular member to assume a predetermined curved shape, the resilient means being coupled to the distal end of the tubular member and configured to provide the predetermined biasing force so that the flexible distal end of the tubular member is movable against the biasing force provided by the resilient means to assume a shape other than its predetermined curved shape, a core member within the distal end of the tubular member, and sleeve means for slidably coupling the resilient means to the core member so that the resilient means is permitted to slip in relation to the adjacent core member when the distal end of the tubular member is moved away from its predetermined curved shape.

4. The apparatus of claim 3, wherein the core member is made of a resilient material preformed to define another predetermined curved shape.

5. An apparatus comprising

an elongated tubular member having a hollow flexible tip for insertion into a body,

a preformed spring coupled to the flexible tip, the preformed spring bending the hollow flexible tip to assume a predetermined curved shape, a shape-control element coupled to the flexible tip, and a control mechanism configured to vary the shape of the shape-control element within the elongated tubular member.

6. An apparatus comprising an elongated hollow tubular member having a proximal end and a hollow flexible distal end for insertion into a body,

resilient means located within said hollow tubular member for applying a predetermined biasing force to move the flexible distal end of the tubular member to assume a predetermined curved shape, the resilient means being coupled to the distal end of the hollow tubular member and configured to provide the predetermined biasing force so that the flexible distal end of the tubular member is movable against the biasing force provided by the resilient means to assume a shape other than its predetermined curved shape, and a core member within the hollow flexible distal end, the resilient means being disposed in the hollow tubular member in a space provided between the core member and the hollow flexible distal end.

7. The apparatus of claim 6, further comprising means in said space for slidable coupling the resilient means to the core member so that the resilient means is permitted to slip in relation to the adjacent core member when the hollow flexible distal end is moved away from its predetermine curved shape.

8. An apparatus comprising

an elongated tubular member having a proximal end and a flexible distal end for insertion into a body,

resilient means having a high degree of flexibility without exceeding its elastic limit providing a predetermined bias within the distal end of the tubular member for applying a force to move the distal end of the tubular member in a first direction to assume a predetermined curved shape, the resilient means being coupled to the elongated tubular member,

means for applying a steering force to selectively move the distal end of the tubular member in a second direction away from the first direction to overcome the force applied by the resilient means without exceeding the elastic limit of the resilient means so that the distal end of the tubular member is moved to assume a selected shape significantly different than its predetermined curved shape and grater than a slight bending from its predetermined shape and, wherein each resilient means returns the tubular member to the predetermined curved shape upon release of the steering force, the applying means being coupled to the elongated tubular member.

9. An apparatus comprising

an elongated tubular member having a hollow flexible tip for insertion into a body,

a preformed spring having a high degree of flexibility without exceeding its elastic limit and coupled to the hollow flexible tip, the preformed spring bending the hollow flexible tip in a first direction to assume a predetermined curved shape,

means for applying a steering force to selectively move the hollow flexible tip in a second direction away from the first direction to overcome bending force applied by the preformed spring without exceeding the elastic limit of the preformed spring so that the hollow flexible tip is moved to assume a selected shape significantly different than its predetermined curved shape and grater than a slight bending from its predetermined shape, and wherein the hollow flexible tip is returned to its predetermined curved shape upon release of the steering force, the applying means being coupled tot he elongated tubular member.

10. The apparatus of claim 9, wherein the applying means includes a shape control element of variable shape coupled to the hollow flexible tip and a control mechanism configured to vary the shape of the shape control element within the hollow flexible tip to cause the hollow flexible tip to move to assume a selected shape other than its predetermined curved shape.