Method of radiofrequency ablation

• US 5,246,438 A
• Filed: 01/09/1992
• Issued: 09/21/1993
• Est. Priority Date: 11/25/1988
• Status: Expired due to Fees

• Current Assignee: Innovative Cardiac Solutions, Inc.
• Original Assignee: Sensor Electronics Corp.
• Inventors: Langberg, Edwin
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US07/819,597
• Time in Patent Office: 621 Days
• Field of Search: 128/784, 128/786, 128/401, 128/642, 600/12, 606/33, 606/41
• US Class Current: 606/33
• CPC Class Codes: A61B 18/08 by means of electrically-heated probes
• CPC Class Codes: A61B 18/1233 with circuits for assuring patient safety
• 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 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 2018/00107 Coatings on the energy applicator
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/1846 Helical antennas
• CPC Class Codes: A61M 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61N 1/06 for high-frequency therapy
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals
• CPC Class Codes: A61N 1/403 for thermotherapy, e.g. hyperthermia

Abstract

A cardiac ablation apparatus including a solenoidal antenna, monitoring electrodes, and a coupling network at a distal end of a catheter transmission line, and another coupling network at the proximal end of the catheter transmission line to connect the catheter to the source of radiofrequency (RF) power and to an intracardiac electrogram monitor. Solenoidal antenna design includes single and multiple windings with varying geometrical features. Plated plastic tri-axial design of a transmission line offers unitary fabrication. A catheter with variable impedance electrode and gap coatings has features useful for both ablation and for hyperthermia applications.

Claims

1. A method of thermally destroying myocardial tissue in a chamber of the heart to treat arrythmia comprising the steps of

introducing into the heart chamber a catheter body that carries an antenna having an axis,

conducting eletromagnetic power to the antenna while the catheter body is immersed in blood in the chamber, and

conditioning the antenna to emit a helically generated electromagnetic field about the antenna axis that penetrates, heats, and thermally destroys myocardial tissue beyond the catheter body.

3. A method according to claim 1 or 2 and further including the step of monitoring an endocardial signal.

4. A method according to claim 1 or 2

wherein in the step of emitting the electromagnetic field, the antenna is conditioned to emit the electromagnetic field symmetrically about the axis of the antenna.

5. A method according to claim 1 or 2

wherein in the step of emitting the electromagnetic field, the antenna is conditioned to emit the electromagnetic field asymmetrically about the axis of the antenna.

2. A method of thermally destroying myocardial tissue in a chamber of the heart to treat arrythmia comprising the steps of

introducing into the heart chamber a catheter body that carries a solenoidal antenna having an axis,

conducting electromagnetic power to the solenoidal antenna while the catheter body is immersed in blood in the heart chamber, and

conditioning the solenoidal antenna to emit an electromagnetic field about the antenna axis to penetrate, heat, and thermally destroy myocardial tissue beyond the catheter body.