Noninvasive method for identifying coronary disfunction utilizing electrocardiography derived data

• US 6,223,073 B1
• Filed: 09/20/1999
• Issued: 04/24/2001
• Est. Priority Date: 04/06/1995
• Status: Expired due to Term

• Current Assignee: Ronald D. Seegobin
• Original Assignee: Ronald D. Seegobin
• Inventors: Seegobin, Ronald D.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US09/399,602
• Time in Patent Office: 582 Days
• Field of Search: 600/515, 600/516, 600/517, 600/518
• US Class Current: 600/515
• CPC Class Codes: A61B 5/35 by template matching
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A method of analyzing experimentally derived electrocardiograph (ECG) data, and system for practicing said method, which allow tracking of subject cardiac status change and which allow accurate catagorization of subjects into various abnormal and normal classifications is disclosed. The presently preferred embodiment applies an algorithm which compares representative parameter, (eg. root-mean-square (RMS) mean), values derived from analysis of a selected portion of a single cycle of an ECG PQRST waveform obtained from investigation of a subject, to similarly derived representative parameter, (eg. RMS mean and RMS standard deviation), values for a composite ECG waveform present in a compiled data bank derived from (ECG) investigation of numerous subjects who were documented as normals, typically in each of a plurality of frequency range bands. A highly diagnostic numerical “Score” is calculated by addition of “Score” components found to be acceptable under certain mathematical criteria, and provided by the algorithm. Visually interpretable time domain and power spectral density plots enhance the method. In addition, comparison of the calculated “Score” to subject cardiac ejection fraction provides indication of risk for sudden death as does the presence of “rhomboids” following a QRS complex in frequency domain plots. The present method is directly adapted to tracking subject cardiac status change by substituting a baseline subject data set for the normal population data set.normal population data set.

Claims

1. A noninvasive method of investigating cardiac status of a subject and enabling classification of said subject into normal and abnormal cardiac categories utilizing electrocardiography ECG data obtained therefrom, comprising the steps of:

a. obtaining data from a selection from the group consisting of;

an ECG cycle from a subject, and

a plurality of ECG cycle(s) from said subject, followed by calculating an average selected ECG cycle portion data set by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle(s);

and obtaining data from a selection from the group consisting of;

an ECG cycle from a subject identified as normal, and

a plurality of ECG cycle(s) from said subject(s) identified as normal, followed by calculating an average selected ECG cycle portion by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s);

then selecting frequency band(s), and separately applying necessary filtering techniques to said data obtained from said subject and to said data obtained from subject(s) identified as normal, to separate the data obtained from said subject into at least one frequency band(s), and said data obtained from said subject(s) identified as normal into essentially equivalent frequency band(s);

b. establishing criteria for, and in line therewith selecting some ECG cycle portion and arriving at representative parameter(s) for each selected frequency band for data obtained from each of the subject and the subject(s) identified as normal;

c. comparing said subject representative parameter(S) with corresponding subject(s) identified as normal representative parameter(s); and

d. combining selected differences between corresponding subject and subject(s) identified as normal representative parameter(s) to arrive at a score, said score being the result of differences in magnitudes of corresponding subject and normal representative parameter(s);

e. providing an output means and presenting said score by use thereof; and

f. utilizing said score as desired.

2. A noninvasive method of investigating cardiac status of a subject and enabling classification of said subject into normal and abnormal cardiac categories utilizing electrocardiography ECG data obtained therefrom, as in claim 1, said method further comprising as additional steps a grouping of steps selected from the group consisting of:

g., h. and i;

j., k, and l; and

m. and n.;

said steps g., h., and i., being;

g. determining the subject'"'"'s cardiac ejection fraction, (in percent);

h. dividing said “

score”

by said cardiac ejection fraction, (in percent);

i. providing an output means and presenting the result provided in step h. therewith, and if said result is determined to be greater than one (1.0), considering said subject as at high risk for sudden death;

and said steps j., k., and l. being;

j. providing at least a coordinate system consisting of magnitude vs. time, and optionally a coordinate system consisting of magnitude vs. frequency, and in step b. selecting a portion of the ECG cycle including the region beyond the QRS complex and before the T wave;

k. for said ECG cycle portion, performing calculations necessary to plot and display normal subject population and subject ECG data as a function of at least time and optionally frequency, to respectively provide as desired, visually interpretable plots of ECG magnitude and power spectral density data, observation of which provides an indication of the cardiac status of said subject; and

l. providing an output display means and visually plotting and displaying therewith at least a magnitude vs. time plot for said ECG cycle portion beyond the QRS complex and before the T wave, then noting if Rhomboids are therewithin, and if present, considering said subject as at high risk for sudden death; and

said steps m. and n. being;

m. determining realtive magnitude pattern(s) amongst at least one selection from the group consisting of;

subject representative parameter values; and

ratios of subject representative parameter values; and

n. providing an output means, and via said output means obtaining and utilizing said relative magnitude pattern(s) as additional basis for investigating the cardiac status of said subject.

3. A noninvasive method of investigating cardiac status of a subject and enabling classification of said subject into normal and abnormal cardiac categories utilizing electrocardiography ECG data obtained therefrom, said method comprising, in a functional sequence, performance of the steps of:

a. obtaining data from ECG cycle(s) from each of a multiplicity of members of a population of subjects who have been documented as normal subjects, in that they do not show risk factors for, or demonstrate detectable cardiac abnormality, by providing, selecting and monitoring a lead of an ECG system;

b. establishing criteria for, and in line therewith selecting some ECG cycle portion and defining cycle portion data points therewithin, and calculating an average selected ECG cycle portion data set for said monitored ECG system lead by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s) obtained from each of a number of members of said multiplicity of members of a population of subjects who have been documented as normal subjects, each said calculated average selected ECG cycle portion data set being a composite data set of said selected ECG cycle portion for said population of normal subjects;

c. obtaining data from a selection from the group consisting of;

an ECG cycle from a subject, and

a plurality of ECG cycle(s) from said subject, followed by calculating an average selected ECG cycle portion data set for said monitored ECG system lead by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s);

by monitoring of said ECG system lead, said ECG system lead monitored being the same as the monitored ECG system lead utilized in step a. to obtain data utilized in step b.;

d. selecting said ECG cycle portion, which is essentially that selected in step b. for a monitored ECG system lead to provide a data set;

e. calculating corresponding representative parameter(s) from resulting data sets calculated in steps b. and d., for said monitored ECG system lead, for, respectively, said normal subject population and said subject;

f. comparing subject to corresponding normal subject population representative parameter(s), and combining results thereof to arrive at a “

score”

, the magnitude of which “

score”

results from difference(s) between magnitude(s) of corresponding normal subject population, and subject representative parameter(s), which “

score”

magnitude increases when said difference(s) in magnitude(s) between corresponding normal subject population, and subject, representative parameter(s) increase, the magnitude of which “

score”

provides an indication of the cardiac status of said subject, with a “

score”

near zero being indicative of a subject properly categorized as a cardiac normal in that the magnitude(s) of subject representative parameter(s) are generally more closely matched to the magnitude(s) of corresponding normal subject population representative parameter(s), and with a progressively higher “

score”

being indicative of a subject progressively more properly categorized as a cardiac abnormal in that the magnitude(s) of subject representative parameter(s) are generally progressively less closely matched to the magnitude(s) of corresponding normal subject population representative parameter(s);

then providing an output means for presenting said score and outputting said score.

4. A noninvasive method of investigating cardiac status of a subject and enabling classification of said subject into normal and abnormal cardiac categories utilizing the electrocardiography ECG data obtained therefrom as in claim 3, said method further comprising as additional steps a grouping of steps selected from the group consisting of:

g., h. and i;

j., k, and l; and

m. and n.;

said steps g., h., and i., being;

g. determining the subject'"'"'s cardiac ejection fraction, (in percent);

h. dividing said “

score”

by said cardiac ejection fraction, (in percent);

i. providing an output means and presenting the result provided in step h. therewith, and if said result is determined to be greater than one (1.0), considering said subject as at high risk for sudden death;

and said steps j., k., and l. being;

j. providing at least a coordinate system consisting of magnitude vs. time, and optionally a coordinate system consisting of magnitude vs. frequency, and in step b. selecting a portion of the ECG cycle including the region beyond the QRS complex and before the T wave;

k. for said ECG cycle portion, performing calculations necessary to plot and display normal subject population and subject ECG data as a function of at least time and optionally frequency, to respectively provide as desired, visually interpretable plots of ECG magnitude and power spectral density data, observation of which provides an indication of the cardiac status of said subject; and

l. providing an output display means and visually plotting and displaying therewith at least a magnitude vs. time plot for said ECG cycle portion beyond the QRS complex and before the T wave, then noting if Rhomboids are therewithin, and if present, considering said subject as at high risk for sudden death; and

m. determining realtive magnitude pattern(s) amongst at least one selection from the group consisting of;

subject representative parameter values; and

ratios of subject representative parameter values; and

n. providing an output means, and via said output means obtaining and utilizing said relative magnitude pattern(s) as additional basis for investigating the cardiac status of said subject.

5. A noninvasive method of investigating cardiac status of a subject and enabling classification of said subject into normal and abnormal cardiac categories utilizing electrocardiography ECG data obtained therefrom, as in claim 3, which method further comprises performance of the additional steps of calculating, and comparing ratio(s) of subject, to corresponding ratio(s) of normal subject population, representative parameters, and combining results thereof with those from comparing subject to corresponding normal subject population, representative parameter(s), in arriving at said “

score”

, the magnitude of which “

score”

then further results from difference(s) between magnitude(s) of corresponding normal subject population and subject ratio(s) of representative parameters, which “

score”

magnitude increases when difference(s) in magnitude(s) between corresponding normal subject population, and subject, ratio(s) of representative parameters increase.

6. A noninvasive method of investigating cardiac status of a subject and enabling classification of said subject into normal and abnormal cardiac categories utilizing electrocardiography ECG data obtained therefrom as in claim 5, said method further comprising as additional steps a grouping of steps selected from the group consisting of:

g., h. and i;

j., k, and l; and

m. and n.;

said steps g., h., and i., being;

g. determining the subject'"'"'s cardiac ejection fraction, (in percent);

h. dividing said “

score”

by said cardiac ejection fraction, (in percent);

i. providing an output means and presenting the result provided in step h. therewith, and if said result is determined to be greater than one (1.0), considering said subject as at high risk for sudden death;

and said steps j., k., and l. being;

j. providing at least a coordinate system consisting of magnitude vs. time, and optionally a coordinate system consisting of magnitude vs. frequency, and in step b. selecting a portion of the ECG cycle including the region beyond the QRS complex and before the T wave;

k. for said ECG cycle portion, performing calculations necessary to plot and display normal subject population and subject ECG data as a function of at least time and optionally frequency, to respectively provide as desired, visually interpretable plots of ECG magnitude and power spectral density data, observation of which provides an indication of the cardiac status of said subject; and

l. providing an output display means and visually plotting and displaying therewith at least a magnitude vs. time plot for said ECG cycle portion beyond the QRS complex and before the T wave, then noting if Rhomboids are therewithin, and if present, considering said subject as at high risk for sudden death; and

said steps m. and n. being;

m. determining realtive magnitude pattern(s) amongst at least one selection from the group consisting of;

subject representative parameter values; and

ratios of subject representative parameter values; and

n. providing an output means, and via said output means obtaining and utilizing said relative magnitude pattern(s) as additional basis for investigating the cardiac status of said subject.

7. A noninvasive method of tracking cardiac status of a subject utilizing electrocardiography ECG data obtained therefrom, said method comprising, in a functional sequence, performance of the steps of:

a. obtaining data from a selection from the group consisting of;

an ECG cycle from a subject, and

a plurality of ECG cycle(s) from said subject, followed by calculating an average selected ECG cycle portion data set for said monitored ECG system lead by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s);

by monitoring a lead of an ECG system;

b. establishing criteria for, and in line therewith selecting some ECG cycle portion and defining cycle portion data points therewithin, and calculating an average selected ECG cycle portion data set for said monitored ECG system lead by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s) obtained from said subject, and selecting a plurality of frequency bands and applying filtering techniques, to provide a plurality of data sets for said monitored ECG system lead monitored, each said data set being an initial composite data set of said selected ECG cycle portion for said subjects in a monitored lead and selected frequency band range;

c. obtaining follow-on data from a selection from the group consisting of;

an ECG cycle from said subject, and

a plurality of ECG cycle(s) from said subject, followed by calculating an average selected ECG cycle portion data set for said monitored ECG system lead by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s);

from said subject at a later time, by monitoring said lead of said ECG system, said ECG system lead monitored being the same as the monitored ECG system lead utilized in step a. to obtain data utilized in step b.;

d. selecting some ECG cycle portion, said ECG cycle portion being essentially that selected in step b. for said initial subject data for a monitored ECG system lead, and applying filtering techniques which are essentially those applied in step b. for said initial subject data, to provide a plurality of data sets for said monitored ECG system lead;

e. calculating corresponding representative parameter(s) from resulting composite data sets calculated in steps b. and d., in said selected frequency band ranges for said monitored ECG system lead, for respectively, said initial subject data and said follow-on subject data;

f. comparing values for at least one member of the group consisting of;

initial subject to corresponding follow-on subject representative parameter(s), and

specific ratio(s) of initial subject to corresponding specific ratio(s) of follow-on subject representative parameters,

and combining results thereof to arrive at a “

score”

;

the magnitude of which “

score”

results from difference(s) between magnitude(s) of corresponding initial subject, and follow-on subject representative parameter(s) and/or ratio(s) of initial subject representative parameters, and follow-on subject representative parameters;

which “

score”

magnitude increases when said difference(s) in magnitude(s) between corresponding initial subject, and follow-on subject, representative parameter(s) and/or ratio(s) of initial subject representative parameters, and follow-on subject representative parameters increase, the magnitude of which “

score”

provides an indication of a change in cardiac status of said subject, with a “

score”

near zero being indicative of a subject properly categorized as having undergone no cardiac change, and with a progressively higher “

score”

being indicative of a subject progressively more properly categorized as a subject who has undergone cardiac changes; and

g. providing an output means and presenting said score therewith;

said method optionally further comprising as additional step(s) groupings of steps selected from the group consisting of;

h., i. and j;

k., l, and j; and

n and o.;

said steps h., i., and j., being;

h. determining the subject'"'"'s cardiac ejection fraction (in percent);

i. dividing said “

score”

determined in step f. by said cardiac ejection fraction, (in percent);

j. providing an output means and presenting the result provided in step i. therewith, and if said result is determined to be greater than one (1.0), considering said subject as at high risk for sudden death;

and said steps k., l. and m. being;

k. providing at least a coordinate system consisting of magnitude vs. time, and optionally a coordinate system consisting of magnitude vs. frequency, and in step b. selecting a portion of the ECG cycle including the region beyond the QRS complex and before the T wave;

l. for said ECG cycle portion, performing calculations necessary to plot and display initial subject and follow-on subject ECG data as a function of at least time and optionally frequency, to respectively provide as desired, visually interpretable plots of ECG magnitude and power spectral density data, observation of which provides an indication of the cardiac status of said subject; and

m. providing an output display means and visually plotting and displaying therewith at least a magnitude vs. time plot for said ECG cycle portion beyond the QRS complex and before the T wave, then noting if Rhomboids are therewithin, and if present, considering said subject as at high risk for sudden death; and

said steps n. and o. being;

n. determining realtive magnitude pattern(s) amongst at least one selection from the group consisting of;

subject representative parameter values; and

ratios of subject representative parameter values; and

o. providing an output means, and via said output means obtaining and utilizing said relative magnitude pattern(s) as additional basis for tracking said subject cardiac status.

8. A noninvasive method of tracking the cardiac status of a subject utilizing electrocardiography ECG data obtained therefrom as in claim 7, which further comprises performance of the step of applying a confidence level acceptance test to results of comparing corresponding specific initial subject to specific follow-on subject representative parameters, and/or corresponding specific ratios of said representative parameters of follow-on subject, to specific ratios of initial normal subject, representative parameters prior to combining results thereof to arrive at a “

score”

, said confidence level test comprising;

a. the step of determining mean and standard deviation acceptance parameters for specific initial subject representative parameter(s) and/or specific ratio(s) of initial subject representative parameter(s) based upon the ECG data from which said composite data set of said selected ECG cycle portion for said initial subject data was calculated;

b. the step of determining an acceptance parameter for each specific corresponding follow-on subject representative parameter and/or each corresponding specific ratio of follow-on subject representative parameters based upon the ECG data from which said composite data set of said selected ECG cycle portion for said follow-on subject data was calculated; and

c. the step of accepting the results of comparing a specific follow-on subject representative parameter to a corresponding specific initial subject representative parameter in arriving at said “

score”

, only if the acceptance parameter for said specific follow-on subject representative parameter is set off by at least one associated initial subject acceptance standard deviation from the acceptance mean of the corresponding specific initial subject representative parameter; and

/or accepting the results of comparing a specific ratio of follow-on subject representative parameters to a corresponding specific ratio of representative parameters for said initial subject population, in arriving at said “

score”

, only if the acceptance parameter of said specific ratio of said follow-on subject representative parameters is set off by at least one associated initial subject acceptance standard deviation from the acceptance mean of said corresponding specific ratio of initial subject representative parameters.

9. A noninvasive method of tracking cardiac status change in a subject utilizing electrocardiography ECG data obtained therefrom as in claim 7, in which said follow-on data is obtained at a time after acquisition of said initial data selected from the group consisting of:

immediately thereafter as in a continuous monitoring scenario; and

after application of a suitable stress test; and

after intervention; and

after medical therapy;

the benefit being identification of a subject who has undergone cardiac change.

10. A noninvasive method of tracking cardiac status of a subject utilizing electrocardiography ECG data obtained therefrom as in claim 7, which further comprises determining if said subject is at high risk for sudden death by the additional steps of:

a. determining the subject'"'"'s cardiac ejection fraction, (in percent);

b. dividing said “

score”

by said cardiac ejection fraction, (in percent); and

c. utilizing said output means, providing the result determined in step b. by use thereof, and if said result is greater observed than one (1.0), considering said subject as at high risk for sudden death.

11. A noninvasive method of investigating cardiac status of a subject utilizing electrocardiography ECG data obtained therefrom, said method enabling classification of said subject into normal and abnormal cardiac categories and determining if said subject is at high risk for sudden death, said method comprising, in a functional sequence, performance of the steps of:

a. obtaining data from ECG cycle(s) from each of a multiplicity of members of a population of subjects who have been documented as normal subjects, in that they do not show risk factors for, or demonstrate detectable cardiac abnormality, by providing, selecting and monitoring of an ECG system;

b. establishing criteria for, and in line therewith selecting some ECG cycle portion and defining cycle portion data points therewithin, and calculating an average selected ECG cycle portion data set for said a monitored ECG system lead, by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s) obtained from each of a number of said multiplicity of members of a population of subjects who have been documented as normal subjects, and selecting a plurality of frequency bands and applying filtering techniques, to provide a plurality of data sets for said a monitored lead, each said data set being a composite data set of said selected ECG cycle portion for said population of normal subjects in a monitored lead and selected frequency band range;

c. obtaining data from an ECG cycle from a selection from the group consisting of;

an ECG cycle from a subject, and

a plurality of ECG cycle(s) from said subject, followed by calculating an average selected ECG cycle portion data set for said monitored ECG system lead by a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s);

by monitoring an ECG system lead, said monitored ECG system lead being the same as the monitored ECG system lead utilized in step a. to obtain data utilized in step b.;

d. selecting some ECG cycle portion, said ECG cycle portion being essentially that selected in step b. for said normal subject population, selecting a plurality of frequency bands, said selected frequency bands being essentially those selected in step b. for said normal subject population, and applying filtering techniques which are essentially those applied in step b. for said normal subject population, to provide a plurality of data sets for said monitored ECG system lead;

e. calculating corresponding representative parameter(s) and corresponding ratio(s) involving representative parameters from resulting composite data sets calculated in steps b. and d., in said selected frequency band ranges for said monitored ECG system lead, for respectively, said normal subject population and said subject;

f. comparing specific subject and corresponding specific normal subject population representative parameter(s), and combining results thereof with the results of comparing specific ratio(s) of subject to corresponding specific ratio(s) of normal subject population representative parameters, to arrive at a “

score”

, the magnitude of which “

score”

results from difference(s) in magnitude(s) between corresponding subject and normal subject population representative parameter(s) and difference(s) between magnitude(s) of corresponding ratio(s) of normal subject population, and ratio(s) of subject representative parameters, which “

score”

magnitude increases when difference(s) in magnitude(s) between corresponding subject and normal subject population representative parameter(s) increase and difference(s) in magnitude(s) between ratio(s) of corresponding normal subject population, and ratio(s) of subject representative parameters increase, the magnitude of which “

score”

provides an indication of the cardiac status of said subject, with a “

score”

near zero being indicative of a subject properly categorized as a cardiac normal in that magnitude(s) of subject representative parameter(s) are generally more closely matched to the magnitude(s) of corresponding normal subject population representative parameter(s) and magnitude(s) of ratio(s) of subject representative parameters are generally more closely matched to the magnitude(s) of corresponding ratio(s) of normal subject population representative parameters, and with a progressively higher “

score”

being indicative of a subject progressively more properly categorized as a cardiac abnormal in that magnitude(s) of subject representative parameter(s) are generally progressively less closely matched to the magnitude(s) of corresponding normal subject population representative parameter(s) and magnitude(S) of ratio(s) of subject representative parameter(s) are generally progressively less closely matched to the magnitude(s) of ratio(s) of corresponding normal subject population representative parameters;

said method further optionally comprising as additional steps at least one grouping of steps selected from the group consisting of;

g., h. and i;

j., k, and l; and

m. and n.;

said steps g., h., and i., being;

g. determining the subject'"'"'s cardiac ejection fraction, (in percent);

h. dividing said “

score”

by said cardiac ejection fraction, (in percent);

i. providing an output means and presenting the result provided in step h. therewith, and if said result is determined to be greater than one (1.0), considering said subject as at high risk for sudden death;

and said steps j., k., and l. being;

j. providing at least a coordinate system consisting of magnitude vs. time, and optionally a coordinate system consisting of magnitude vs. frequency, and in step b. selecting a portion of the ECG cycle including the region beyond the QRS complex and before the T wave;

k. for said ECG cycle portion, performing calculations necessary to plot and display normal subject population and subject ECG data as a function of at least time and optionally frequency, to respectively provide as desired, visually interpretable plots of ECG magnitude and power spectral density data, observation of which provides an indication of the cardiac status of said subject; and

l. providing an output display means and visually plotting and displaying therewith at least a magnitude vs. time plot for said ECG cycle portion beyond the QRS complex and before the T wave, then noting if Rhomboids are therewithin, and if present, considering said subject as at high risk for sudden death; and

said steps m. and n. being;

m. determining realtive magnitude pattern(s) amongst at least one selection from the group consisting of;

subject representative parameter values; and

ratios of subject representative parameter values; and

n. providing an output means, and via said output means obtaining and utilizing said relative magnitude pattern(s) as additional basis for investigating the cardiac status of said subject.

12. A noninvasive method of investigating cardiac status of a subject and enabling classification of a subject into normal and abnormal cardiac categories utilizing electrocardiography (ECG) data obtained therefrom as in claim 11, which method further comprises performance of the step of applying a confidence level acceptance test to results of comparing subject, to corresponding normal subject population representative parameter(s), and the results of comparing ratios of subject representative parameters to corresponding ratios of normal subject population representative parameters, prior to combining results thereof to arrive at a “

score”

, said confidence level test comprising;

a. the step of determining mean and standard deviation acceptance parameters for specific normal subject population representative parameter(s) and specific ratio(s) of normal subject population representative parameters based upon the (ECG) data from which said composite data set of said selected (ECG) cycle portion for said population of normal subjects was calculated;

b. the step of determining an acceptance parameter for each corresponding specific subject representative parameter and each corresponding specific ratio of subject representative parameters based upon the (ECG) data from which said composite data set of said selected (ECG) cycle portion for said subject was calculated; and

c. the step of accepting the results of comparing a specific subject representative parameter to a corresponding specific normal subject population representative parameter in arriving at said “

score”

, only if the acceptance parameter for said specific subject representative parameter is set off by at least one associated normal subject population acceptance standard deviation from the acceptance mean of the corresponding specific normal subject population representative parameter; and

accepting the results of comparing a specific ratio of subject representative parameters to a corresponding specific ratio of representative parameters for said normal subject population, in arriving at said “

score”

, only if the acceptance parameter of said specific ratio of said subject representative parameters is set off by at least one associated normal subject population acceptance standard deviation from the acceptance mean of said corresponding specific ratio of normal subject population representative parameters.