Endocardial measurement method

• US 5,553,611 A
• Filed: 01/20/1995
• Issued: 09/10/1996
• Est. Priority Date: 01/06/1994
• Status: Expired due to Term

• Current Assignee: St. Jude Medical, Atrial Fibrillation Division, Inc. (Abbott Laboratories)
• Original Assignee: Endocardial Solutions Incorporated (Abbott Laboratories)
• Inventors: Budd, Jeffrey R., Beatty, Graydon E., Hauck, John A.
• Primary Examiner(s): Sykes, Angela D.
• Application Number:
  US08/376,067
• Time in Patent Office: 599 Days
• Field of Search: 128/639, 128/641-2, 128/691-734, 607/122-3, 607/125-8
• US Class Current: 600/374
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6853 with a balloon

Abstract

A collection of measurements are taken from a set of measurement electrodes to determine the position of a catheter in a heart chamber. The preferred measurement catheter includes a relatively large dielectric volume.

Claims

1. A method of measuring distance within the heart using a programmable data processing system, comprising data input means, display means, and data storage means, the method comprising the steps of:

(a) defining a blood exclusion volume within said heart;

(b) positioning a first excitation electrode and a second excitation electrode within said heart, proximate said blood exclusion volume such that said blood exclusion volume is between said first excitation electrode and said second excitation electrode;

(c) placing a first measurement set of electrodes within said heart proximate said blood exclusion volume, said first measurement set having at least a first electrode and a second electrode forming an index set of electrodes;

(d) placing a second measurement set of electrodes within said heart proximate said blood exclusion volume, said second measurement set having at least a third electrode and a fourth electrode, said first measurement set being opposed from said second measurement set;

(d) using the data input means to provide the programmable data processing system with data signals gathered from the first, second, third, and fourth electrodes;

(e) storing the data signals gathered from the first, second, third, and fourth electrodes in the data storage means; and

(f) using the programmable data processing system to perform the steps of;

(1) measuring the impedance between said first and second electrodes forming a first resistance measurement (R1);

(2) measuring the impedance between said third and fourth electrodes forming a second resistance measurement (R2);

(3) applying a first empirically derived coefficient to said first resistance measurement, forming a first measure term;

(4) applying a second empirically derived coefficient to said second resistance measurement, forming a second measure term;

(5) combining said first measure term and said second measure term to determine the distance (D) to said wall from said index electrode set;

(6) displaying on the display means a value representing the distance (D) to said wall from said index electrode set.

2. The method of claim 1 wherein said first measurement set of electrodes lies on a meridian of said blood exclusion volume.

3. The method of claim 2 wherein said first measurement set of electrodes includes a first and second electrode and a third center electrode wherein the center electrode is used as a reference electrode for each of the other electrodes of said first measurement set of electrodes.

4. The method of claim 1 wherein said first measurement set of electrodes lies on a meridian of said blood exclusion volume proximate the equator of said blood exclusion body.

5. The method of claim 1 further comprising the following steps:

incrementing the location of said index set of electrodes and repeating said steps until all measurement sets of electrodes have been indexed.

6. The method of claim 5 further comprising the following steps:

displaying on the display means a value representing the volume of said heart from said distance measures.

7. The method of claim 5 further comprising the following steps:

displaying on the display means a value representing the motion of the heart wall from said distance measures.