Cardiac shock electrode system and corresponding implantable defibrillator system

• US 6,633,780 B1
• Filed: 06/05/2000
• Issued: 10/14/2003
• Est. Priority Date: 06/07/1999
• Status: Expired due to Term

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Berger, Ronald D.
• Primary Examiner(s): EVANISKO, GEORGE ROBERT
• Application Number:
  US09/586,787
• Time in Patent Office: 1,226 Days
• Field of Search: 607/4, 607/5, 607/119, 607/129, 607/130, 607/148
• US Class Current: 607/129
• CPC Class Codes: A61N 1/0563 specially adapted for defibrillation or cardioversion
• CPC Class Codes: A61N 1/3918 characterised by shock pathway, e.g. by electrode configuration

Abstract

An implantable cardioverter defibrillator (ICD) system includes an internal electrode placed in the right ventricle of the heart, and a flexible array (that includes a plurality of electrodes) placed over a significant portion of the heart. Defibrillation shocks are applied between the internal electrode in the ventricle and the electrodes in the flexible array. Because the electrodes in the flexible array surround a significant portion of the heart, the array functions as a quasi-Faraday cage and is thus capable of confining a significant portion of the defibrillation shock field to the heart itself. As a result, defibrillation shocks are less likely to activate extracardiac muscle(s) and/or nerve tissue(s) within the surrounding chest. Application of the shocks is thus less painful to the patient.

Claims

1. An implantable cardioverter defibrillator (ICD) system for applying electric shock to a heart of a patient in a shock applying mode, the ICD system comprising:

an internal electrode adapted to be placed inside of the heart of the patient;

a quasi-Faraday cage including a plurality of different electrodes, so that the electric shock is to be applied between the quasi-Faraday cage which is adapted to be located outside of the heart and the internal electrode adapted to be placed inside of the heart;

wherein said electrodes of the quasi-Faraday cage are adapted to be wrapped around at least about 50% of the heart during application of the electric shock so as to confine a significant portion of a defibrillation shock field to the heart itself so as to prevent the shock from significantly stimulating extracardiac muscle(s) and/or nerve(s) tissue;

switching circuit; and

wherein said electrodes of said quasi-Faraday cage are selectively coupleable to one another via said switching circuitry so that in a mode of operation of the ICD system where no shock is applied to the heart the electrodes of said quasi-Faraday cage are electrically isolated from one another, and in the shock-applying mode of the ICD system where shock is applied to the heart the electrodes of said quasi-Faraday cage are electrically coupled to one another via said switching circuitry so that the electric shock is adapted to be applied to the heart between (a) the internal electrode, and (b) the coupled electrodes of said quasi-Faraday cage so that application of the shock to a patient is less painful.

2. The ICD system of claim 1, further comprising insulating material provided between adjacent ones of said electrodes, and wherein said electrodes of said quasi-Faraday cage are in the form of an array of electrodes.

3. An implantable cardioverter defibrillator (ICD) system for applying electric shock to a heart of a patient, the ICD system comprising:

an internal electrode adapted to be placed inside of the heart of the patient;

switching circuit;

a quasi-Faraday cage including a plurality of different selectively coupleable electrodes which are selectively electrically coupleable to one another via said switching circuitry, wherein the electric shock is adapted to be applied to the heart between (a) the internal electrode, and (b) the electrodes of the quasi-Faraday cage when the electrodes of the cage are electrically coupled via the switching circuitry; and

wherein the electrodes of the quasi-Faraday cage surround at least about 70% of the heart during application of the electric shock so as to confine a significant portion of a shock field to the heart itself so as to prevent the shock from significantly stimulating extracardiac muscle(s) and/or nerve(s) tissue.

4. An implantable cardioverter defibrillator (ICD) system for applying electric shock to a heart of a patient, the ICD system having an internal electrode adapted to be placed inside of the heart of the patient, the ICD system comprising:

a quasi-Faraday cage including electrodes;

wherein electrodes of the quasi-Faraday cage are adapted to be wrapped around at least about 60% of the heart during application of the electric shock so that electric shock is adapted to be applied to the heart between the electrodes of the quasi-Faraday cage and the electrode of the ICD adapted to be located inside of the heart to make the shock less painful as a significant portion of a defibrillation shock field is confined to the heart itself so as to prevent the shock from significantly stimulating extracardiac tissue.