Ablation catheter with selectively deployable electrodes

• US 4,976,711 A
• Filed: 04/13/1989
• Issued: 12/11/1990
• Est. Priority Date: 04/13/1989
• Status: Expired due to Fees

• Current Assignee: Everest Medical Corp. (Olympus Corporation)
• Original Assignee: Everest Medical Corp. (Olympus Corporation)
• Inventors: Rydell, Mark A., Stasz, Peter, Parins, David J.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US07/337,426
• Time in Patent Office: 607 Days
• Field of Search: 606/33, 606/41, 606/45, 606/46, 606/48, 606/50, 606/7, 128/786
• US Class Current: 606/48
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2018/00196 reciprocating lengthwise
• CPC Class Codes: A61B 2018/00232 having an irregular shape
• CPC Class Codes: A61B 2018/1435 Spiral
• CPC Class Codes: A61B 2018/1861 with an instrument inserted into a body lumen or cavity, e.g. a catheter
• CPC Class Codes: A61M 2025/1086 having a special balloon surface topography, e.g. pores, protuberances, spikes or grooves
• CPC Class Codes: A61M 3/0279 Cannula; Nozzles; Tips; their connection means

Abstract

A RF ablation catheter for removing athero-stenotic lesions or modifying the tissue characteristics of the interior walls of selected blood vessels is described. The catheter is characterized in having a tip member which during the initial placement of the catheter within the vascular system so that the distal tip member is disposed in a working relation with the lesion to be removed, means are provided for increasing the cross-sectional profile of the tip members to thereby cause it to move into engagement with the lesion to be excised. The application of an RF voltage across a pair of bipolar electrodes is used to create an electric arc for effecting the cutting action, or alternatively, just sufficient RF energy to sear or otherwise alter the tissue surfaces engaged by the distal tip member.

Claims

1. An RF tissue ablating catheter comprising, in combination:

(a) an elongated, flexible, plastic tubular member having a proximal end and a distal end and a lumen extending from said proximal end to said distal end;

(b) a tip member affixed to the distal end of said tubular member, said tip member comprising

(i) a hollow, generally cylindrical body having a window opening formed through a sidewall of said body,

(ii) an inflatable expander bonded to said cylindrical body for producing lateral displacement of said tip member upon inflation thereof,

(iii) a pair of bipolar electrodes mounted in closely spaced relation in said body and at least a portion of said pair of electrodes being exposed through said window,

(iv) an inflation port passing through said body in fluid communication with said lumen and the interior of said expander, and

(c) conductor means extending from said proximal end of said tubular member to said pair of electrodes for applying an RF voltage across said pair of bipolar electrodes sufficient to cut tissue, the spacing between said pair of bipolar electrodes being sufficiently close to each other to permit electrical breakdown therebetween when bridged by said tissue.

2. The catheter as in claim 1 and further including a fixed guidewire extending distally from said tip member.

3. The catheter as in claim 1 wherein said tip member is formed from a ceramic selected from the group comprising aluminum nitride and silicon nitride.