US 5,609,158 A · Apparatus and method for predicting cardiac arrhythmia by detection of micropotentials and analysis of all ECG segments and intervals

Abstract

An apparatus and method for the acquisition and analysis of electrocardiogram signals, to non-invasively detect and quantify presence of abnormal cardiac conduction patterns in patients at risk of heart disease, e.g. ventricular tachycardia; atrial fibrillation and flutter. Signals from the orthogonal X, Y and Z surface leads are amplified, digitized and either stored for later processing, or processed immediately. The incoming beats can either be R wave-triggered, aligned and ensemble-averaged for studies of patients at risk for ventricular pathologies such as ventricular tachycardia, or P wave-triggered, aligned and ensemble-averaged for studies of patients at risk for atrial pathologies, e.g. atrial fibrillation and flutter. QRS onset and offset, and P wave onset and offset, are calculated for ventricular and atrial post-analysis applications, respectively. The windowed Fourier transform of the second derivative (acceleration) of the signal-averaged ECG is calculated for particular regions of interest for each lead, including the intra-QRS, ST-segment, T and P wave regions. A novel Spectral Change Index, calculated from the resulting "acceleration spectrum" for each lead as well as the composite (X+Y+Z) lead, serves to quantify the degree of spectral "fragmentation" within a prespecified bandwidth. It thereby provides a quantitative index to help stratify patients at risk for potentially lethal cardiac (atrial and ventricular) pathologies.

Claims27

Dependent claims

A method for detecting micropotentials to identify cardiac arrhythmia comprising the steps of:

selecting a segment of interest of an electrocardiographic signal of one cardiac cycle;
generating a profile waveform representative of a temporal attribute of said segment of interest;
deriving a frequency domain spectral representation of said profile waveform, said frequency domain representation being representative of said segment of interest with high frequency micropotentials being amplified therein;
defining a bandwidth of interest of frequencies in said spectral representation;
determining a gradient from said spectral representation for each of a plurality of the frequencies within said bandwidth of interest;
obtaining a representative maximum amplitude of said spectral representation for the frequencies within said bandwidth of interest;
comparing said representative maximum amplitude and said gradients from said spectral representation for each of the plurality of the frequencies to detect the micropotentials in the segment of interest of the electrocardiographic signal;
and
quantifying a degree of spectral fragmentation within said bandwidth of interest from said comparing of said representative maximum amplitude and said gradients to identify cardiac arrhythmia.

6 more elements

An apparatus for detecting micropotentials to identify cardiac arrhythmia comprising:

a computer;
a signal storage device addressable by said computer;
a signal acquisition module operable with said computer to select a segment of interest of an electrocardiographic signal of one cardiac cycle, to save said segment of interest in said signal storage device and to generate a profile waveform representative of a temporal attribute of said segment of interest;
a frequency domain transformation program utilized by said computer to derive a spectral representation of said profile waveform representative of said segment of interest with high frequency micropotentials being amplified within a bandwidth of interest for characterizing a degree of variation within said spectral representation to detect the micropotentials in said segment of interest of the electrocardiographic signal;
and
said frequency domain transformation program quantifying a degree of spectral fragmentation within said bandwidth of interest to identify cardiac arrhythmia.

3 more elements

Dependencies are inferred from the claim text.

Apparatus and method for predicting cardiac arrhythmia by detection of micropotentials and analysis of all ECG segments and intervals

Life of this patent

Apparatus and method for predicting cardiac arrhythmia by detection of micropotentials and analysis of all ECG segments and intervals

Life of this patent

Abstract

Claims27