Method for analysis of electrocardiographic signal QRS complex

• US 5,025,794 A
• Filed: 08/30/1988
• Issued: 06/25/1991
• Est. Priority Date: 08/30/1988
• Status: Expired due to Term

• Current Assignee: Arrhythmia Research Technology, Inc.
• Original Assignee: Corazonix Corporation (Micron Solutions, Inc.)
• Inventors: Albert, David E., Berbari, Edward J.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US07/238,503
• Time in Patent Office: 1,029 Days
• Field of Search: 128/696, 128/702, 128/705, 128/710, 364/413.06
• US Class Current: 600/509
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61B 5/7257 using Fourier transforms

Abstract

A method and apparatus for examining the QRS complex of ECG signals to detect minute late potentials. The system functions to filter the QRS signals bi-directionally, and further separately processes the two filtered signals through selected window functions before summation. The summed signal is then passed through a smoothing function to produce an output signal of ideal phase that delineates any late potentials within the QRS complex.

Claims

1. A method for determining anomalous late potentials in the QRS complex of an electrocardiographic beat signal, comprising:

deriving the QRS signal of the beat signal as a series of digital sample values at a selected sample rate;

filtering the QRS signal sample values through a digital filter of selected pass band;

filtering the QRS signal sample values in reversed time order through a digital filter of said selected pass band;

processing each of the filtered QRS signal in accordance with a predetermined window function and summing the resulting signal to produce a QRS summation signal; and

smoothing the QRS summation signal to produce a QRS signal replica accentuating the non-random late potential signal components within the QRS low amplitude signal sector.

2. A method as set forth in claim 1 wherein the steps of filtering each include:

selecting a filter that is a low pass type.

3. A method as set forth in claim 1 wherein the steps of filtering each include:

selecting a filter that is a highpass type.

4. A method as set forth in claim 1 wherein the steps of filtering each include:

selecting a filter that is a fourth order Butterworth type.

5. A method as set forth in claim 4 wherein:

said QRS signal is derived from a selected one of the X, Y and Z electrocardiographic responses and averaged over a selected duration.

6. A method as set forth in claim 1 wherein:

said window function is a rectangular type.

7. A method as set forth in claim 1 wherein:

said window function is a Blackman-Harris type.

8. A method as set forth in claim 1 wherein:

said window function is a Hanning type.

9. A method as set forth in claim 1 wherein:

said window function is a Hamming type.

10. A method as set forth in claim 1 wherein:

said QRS signal is derived from a selected one of the X, Y and Z electrocardiographic responses and averaged over a selected duration.