Expandable atherectomy cutter with flexibly bowed blades

• US 4,966,604 A
• Filed: 01/23/1989
• Issued: 10/30/1990
• Est. Priority Date: 01/23/1989
• Status: Expired due to Term

• Current Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Original Assignee: Interventional Technologies Incorporated (Boston Scientific Corporation)
• Inventors: Reiss, Robert E.
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US07/299,148
• Time in Patent Office: 645 Days
• Field of Search: 606/159, 606/170, 606/167, 606/180, 606/160, 606/127, 606/113, 606/198, 604/22, 128/751, 128/752
• US Class Current: 606/159
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 2017/22038 with a guide wire

Abstract

An expandable atherectomy cutting device comprises a flexible blade having one end connected to a torque tube and the other end connected to a tip. The tip and torque tube are rotatably positioned about a guide wire, and the torque tube is coupled to a drive element for rotating the flexible blade about the guide wire. A mechanism is associated with the tip and torque tube for pulling the tip toward the torque tube to cause the flexible blade to bow outwardly away from the guide wire to expand its radius of cutting action. The mechanism for causing the flexible blade to bow outwardly includes a base rotatably mounted in slidable relation in the torque tube, and a series of desmodromic filaments connecting the base to the tip for pulling the tip toward the torque tube. The flexible blade includes a bend so that it bows outwardly rather than inwardly. The amount of expansion is controlled by a control element coupled to the drive element so that it can be controllably expanded through an infinite variety of positions within a continuous range, and further, can be expanded while the blade is rotating.

Claims

1. An expandable atherectomy cutting device comprising:

a guide wire;

a desmodromic wire;

a torque tube rotatably positioned about said guide wire, said torque tube having a sidewall including a channel for slidably receiving said desmodromic wire;

a tip rotatably positioned on said guide wire, said tip being slidable along said guide wire between a first position and a second position;

four flexible blades spaced 90°

apart, each said blade having one end connected to said torque tube and another end connected to said tip, each said flexible blade urging said tip to said first position wherein each said blade defines a first radius of cutting action; and

means associated with said tip and said casing for urging said tip to said second position wherein each said blade defines a second radius of cutting action greater than said first radius of cutting action, said means for urging said tip to said second position comprising a base controllably movable along said torque tube, said base being connected to said tip by said desmodromic wire for drawing said tip into said second position.

2. An expandable atherectomy cutting device as recited in claim 1 wherein there is a plurality of desmodromic filaments attached equally apart.