Systems and methods for positioning multiple electrode structures in electrical contact with the myocardium

• US 5,935,079 A
• Filed: 09/08/1997
• Issued: 08/10/1999
• Est. Priority Date: 03/31/1994
• Status: Expired due to Term

• Current Assignee: EP Technologies Incorporated (Boston Scientific Corporation)
• Original Assignee: EP Technologies Incorporated (Boston Scientific Corporation)
• Inventors: Panescu, Dorin, Swanson, David K.
• Primary Examiner(s): COHEN, LEE S
• Application Number:
  US08/925,196
• Time in Patent Office: 701 Days
• Field of Search: 600/374, 600/381, 600/509, 600/547, 607/122
• US Class Current: 600/509
• 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 2018/1465 Deformable electrodes
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 5/276 Protection against electrode failure
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/304 Switching circuits
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/6858 with a distal basket, e.g. expandable basket
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure

Abstract

Systems and methods evaluate electrical contact between the myocardium and one or more electrodes inside the heart. The systems and methods electrically sense electrical contact between the myocardium and electrodes and generate unitary contact-indicating outputs indicating the presence or absence of electrical contact between the myocardium and each particular electrode. The systems and methods also correlate the electrode-specific unitary outputs to generate a compound contact-indicating output. The compound output represents the aggregate of the electrical contact between the myocardium and multiple electrodes on a multiple electrode array.

Claims

1. A system for evaluating electrical contact between the myocardium and an electrode disposed inside the heart, comprising:

an electrode;

an energy generating element coupled to the electrode and configured to produce an electrical signal at a level below that necessary to activate the myocardium, the electrode emitting the electrical signal;

an indifferent electrode adapted to be situated outside the heart and serving as a return path for the electrical signal; and

means employing the electrical signal for sensing unitary electrical contact between the electrode and the myocardium and for generating a unitary contact-indicating output indicating the presence or absence of electrical contact.

2. The system of claim 1, wherein the system senses electrical contact by measuring myocardial tissue impedance.

3. The system of claim 1, wherein the indifferent electrode is an externally applied skin patch.

4. A system for evaluating electrical contact between the myocardium and an electrode disposed inside the heart, comprising:

an electrode;

an energy generating element coupled to the electrode and configured to produce an electrical signal at a level below that necessary to activate the myocardium, the electrode emitting the electrical signal;

an indifferent electrode adapted for internal positioning in the blood pool and serving as a return path for the electrical signal; and

means employing the electrical signal for sensing unitary electrical contact between the electrode and the myocardium and for generating a unitary contact-indicating output indicating the presence or absence of electrical contact.

5. A system for evaluating electrical contact between the myocardium and an electrode array disposed inside the heart, the electrode array comprising first and second electrodes, the system comprising:

a first circuit configured for sensing unitary electrical contact between the first electrode and the myocardium via an indifferent electrode situated outside the heart, the first circuit further configured for generating a first unitary contact-indicating output indicating the presence or absence of electrical contact, and

a second circuit configured for sensing unitary electrical contact between the second electrode and the myocardium via the indifferent electrode, the second circuit further configured for generating a second unitary contact-indicating output indicating the presence or absence of electrical contact

wherein at least one of the first and second circuits senses unitary electrical contact between the respective electrode and myocardium by emitting from the respective electrode an electrical signal at a level below that necessary to activate the myocardium.

6. The system of claim 5, wherein the first and second unitary contact-indicating outputs are correlated to generate a compound contact-indicating output representing the aggregate electrical contact between the myocardium and the first and second electrodes.

7. The system of claim 5, wherein at least one of the first and second circuits senses electrical contact by measuring myocardial tissue impedance.

8. A system for evaluating electrical contact between the myocardium and an internal electrode disposed inside the heart, comprising:

an energy generating element for supplying the internal electrode with an electrical signal at a level below that necessary to activate the myocardium, the internal electrode emitting the electrical signal;

an indifferent electrode adapted to be situated outside the heart and serving as a return path for the electrical signal;

a signal acquisition element electrically coupled to the indifferent electrode for detecting at least one acquired signal resulting from the emission of electrical energy by the internal electrode, the acquired signal varying with the presence or absence of electrical contact between the internal electrode and the myocardium to thereby differentiate between electrical contact and the absence of electrical contact;

a processing element electrically coupled to the signal acquisition element to compare the acquired signal with an expected signal; and

an output element for generating a contact-indicating output indicating the presence or absence of electrical contact between the internal electrode and the myocardium based upon the comparison between the acquired signal and the expected signal.

9. A method for evaluating electrical contact between the myocardium and an internal electrode disposed inside the heart, comprising:

emitting from the internal electrode an electrical signal at a level below that necessary to activate the myocardium;

providing a return path for the electrical signal via an indifferent electrode adapted to be located outside the heart; and

detecting at least one acquired signal resulting form the emission of electrical energy by the internal electrode, the acquired signal varying with the presence or absence of electrical contact between the internal electrode and the myocardium to thereby differentiate between electrical contact and the absence of electrical contact.

10. The method of claim 9, further comprising

comparing the acquired signal with an expected signal;

and

generating a contact-indicating output signal indicating the presence or absence of electrical contact between the internal electrode and the myocardium based upon the comparison between the acquired signal and the expected signal.