Noninvasive system and method for identifying coronary disfunction utilizing electrocardiography derived data

• US 5,954,664 A
• Filed: 08/07/1997
• Issued: 09/21/1999
• 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:
  US08/908,543
• Time in Patent Office: 775 Days
• Field of Search: 600/515-518
• 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 system and method for analyzing experimentally obtained electrocardiograph ECG data, which allows accurate catagorization of subjects into various abnormal and normal classifications, and which allows acurate tracking of subject cardiac status change, is disclosed. The method applies an algorithm which compares representative parameter, (eg. root-mean-square RMS mean), values derived from analysis of a representative composite of selected portions of a number of ECG PQRST waveforms obtained from ECG investigation of a subject, to similarly derived representative parameter, (eg. RMS mean and RMS standard deviation), values present in a compiled data bank derived from ECG investigation of numerous normals, (or initial subject data), 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 power spectral density plots supplement the method. In addition, comparison of the calculated "Score" to subject cardiac ejection fraction provides indication of risk for sudden death. The present invention is directly adapted to tracking subject cardiac status change by substituting a baseline subject data set for the normal population data set.

Claims

1. An ECG system for practicing 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 at least one lead(s) of said 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 at least one monitored ECG system lead(s) by, for a monitored ECG system lead, 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, for a monitored ECG system lead;

c. obtaining data from ECG cycle(s) from a subject, by monitoring at least one lead(s) of said ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) utilized in step a. to obtain data utilized in step b.;

d. selecting some ECG cycle portion, which is essentially that selected in step b., and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s) by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s) obtained from said subject, each said calculated average selected ECG cycle portion data set being a composite data set of said selected ECG cycle portion for said subject, for a monitored ECG system lead;

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

g. providing an output means for presenting said score;

said ECG system comprising ECG lead(s) which monitor electrodes affixed to a subject or member of a normal subject population, and which provide monitored signal(s) to an ECG monitor, said ECG monitor being functionally interconnected to a computational means which is programmed to accept ECG data from said ECG monitor and practice the method of steps a.-f., said computational means being functionally interconnected to an output means to enable practice of step g.

2. A system for practicing 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 1, 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;

said ECG system computational means being programmed to perform said additional steps.

3. An ECG system for practicing 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, which method further comprises performance of the additional steps of:

a. providing at least one coordinate system selected from the group consisting of magnitude vs. time, and magnitude vs. frequency;

b. for an ECG cycle portion, performing calculations necessary to plot and display and plotting and displaying normal subject population and subject ECG data as a function of at least one parameter selected from the group consisting of time and 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

c. observing and interpreting the displayed plot(s);

said ECG system computational means being programmed to perform said additional step and cause display thereof via output display means.

4. An ECG system for practicing 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 at least one lead(s) of said 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 at least one monitored ECG system lead(s) by, for a monitored ECG system lead, 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, for a monitored ECG system lead;

c. obtaining data from ECG cycle(s) from a subject, by monitoring at least one lead(s) of ECG said system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) utilized in step a. to obtain data utilized in step b.;

d. selecting some ECG cycle portion, which is essentially that selected in step b., and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s) by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected cycle portion for ECG cycle(s) obtained from said subject, each said calculated average selected ECG cycle portion data set being a composite data set of said selected ECG cycle portion for said subject, for a 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., for monitored ECG system lead(s), for, respectively, said normal subject population and said subject;

f. comparing specific ratio(s) of subject to corresponding specific ratio(s) of normal subject population representative parameters, and combining results thereof to arrive at a "score", the magnitude of which "score" results from difference(s) between magnitude(s) of specific corresponding ratio(s) of normal subject population, and ratio(s) of subject representative parameters, which "score" magnitude increases when said difference(s) in magnitude(s) between specific ratio(s) of corresponding normal subject population, and specific 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 the 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 the magnitude(s) of ratio(s) of subject representative parameters are generally progressively less closely matched to the magnitude(s) of ratio(s) of corresponding normal subject population representative parameters;

g. providing an output means for presenting said score;

said ECG system comprising ECG lead(s) which monitor electrodes affixed to a subject or member of a normal subject population, and which provide monitored signal(s) to an ECG monitor, said ECG monitor being functionally interconnected to a computational means which is programmed to accent ECG data from said ECG monitor and practice the method of steps a.-f. said computational means being functionally interconnected to an output means to enable practice of step g.

6. An ECG system for practicing 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 at least one lead(s) 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 at least one monitored ECG system lead(s), by, for a monitored ECG system lead, 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 each said at least one ECG system lead(s) monitored, 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 ECG cycle(s) from a subject, by monitoring at least one lead(s) of said ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) 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, and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s), by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for subject ECG cycle(s), and 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 each said at least one monitored ECG system lead(s), each said data set being a composite data set of said selected ECG cycle portion for said subject in a monitored lead and selected frequency band range;

p1 e. calculating corresponding representative parameter(s) from resulting composite data sets calculated in steps b. and d., in said selected frequency band ranges for monitored ECG system lead(s), for respectively, said normal subject population and said subject;

f. comparing specific subject to specific normal subject population corresponding 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);

g. providing an output means for presenting said score;

said ECG system comprising ECG lead(s) which monitor electrodes affixed to a subject or member of a normal subject population, and which provide monitored signal(s) to an ECG monitor, said ECG monitor being functionally interconnected to a computational means which is programmed to accept ECG data from said ECG monitor and practice the method of steps a.-f., said computational means being functionally interconnected to an output means to enable practice of step g.

5. An ECG system for practicing 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 7, which method further comprises performance of the additional steps of:

a. providing at least one coordinate system selected from the group consisting of magnitude vs. time, and magnitude vs. frequency;

b. for an ECG cycle portion, performing calculations necessary to plot and display and plotting and displaying normal subject population and subject ECG data, as a function of at least one parameter selected from the group consisting of time and 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

c. observing and interpreting displayed plot(s);

said ECG system computational means being programmed to perform said additional step and cause display thereof via output display means.

7. An ECG system for practicing 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 6, which method further comprises performance of the steps of:

a. providing at least one coordinate system selected from the group consisting of magnitude vs. time, and magnitude vs. frequency;

b. for an ECG cycle portion, performing calculations necessary to plot and display and plotting and displaying normal subject population and subject ECG data in at least one frequency band range, as a function of at least one parameter selected from the group consisting of time and 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

c. observing and interpreting displayed plot(s);

said ECG system computational means being programmed to perform said additional step and cause display thereof via output display means.

8. An ECG system for practicing 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 at least one lead(s) 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 at least one monitored ECG system lead(s), by, for a monitored ECG system lead, 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 at least one ECG system lead(s) monitored, 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 ECG cycle(s) from a subject, by monitoring at least one lead(s) of said ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) 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, and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s), by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for subject ECG cycle(s), are 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 at least one monitored ECG system lead(s), each said data set being a composite data set of said selected ECG cycle portion for said subject in a monitored lead and selected frequency band range;

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 monitored ECG system lead(s), for respectively, said normal subject population and said subject;

f. comparing specific ratio(s) of subject to corresponding specific ratio(s) of normal subject population 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 specific ratio(s) of normal subject population and specific ratio(s) of subject representative parameters, which "score" magnitude increases when said difference(s) in magnitude(s) between specific ratio(s) of corresponding normal subject population and 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 the 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 the magnitude(s) of ratio(s) of subject representative parameters are generally progressively less closely matched to the magnitude(s) of ratio(s) of corresponding normal subject population representative parameters;

g. providing an output means for presenting said score;

said ECG system comprising ECG lead(s) which monitor electrodes affixed to a subject or member of a normal subject population, and which provide monitored signal(s) to an ECG monitor, said ECG monitor being functionally interconnected to a computational means which is programmed to accept ECG data from said ECG monitor and practice the method of steps a.-f., said computational means being functionally interconnected to an output means to enable practice of step g.

9. An ECG system for practicing 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 8, which method further comprises performance of the steps of:

a. providing at least one coordinate system selected from the group consisting of magnitude vs. time, and magnitude vs. frequency;

b. for an ECG cycle portion, performing calculations necessary to plot and display and plotting and displaying normal subject population and subject ECG data for at least one frequency band range, as a function of at least one parameter selected from the group consisting of time and 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

c. observing and interpreting displayed plot(s);

said ECG system computational means being programmed to perform said additional step and cause display thereof via output display means.

10. An ECG system for practicing 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 at least one lead(s) 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 at least one monitored ECG system lead(s), by, for a monitored ECG system lead, 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 at least one ECG system lead(s) monitored, 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 ECG cycle(s) from a subject, by monitoring at least one lead(s) of said ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) 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, and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s), by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for subject ECG cycle(s), and 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 at least one monitored ECG system lead(s), each said data set being a composite data set of said selected ECG cycle portion for said subject in a monitored lead and selected frequency band range;

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 monitored ECG system lead(s), 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;

g. providing an output means for presenting said score;

said ECG system comprising ECG lead(s) which monitor electrodes affixed to a subject or member of a normal subject population, and which provide monitored signal(s) to an ECG monitor, said ECG monitor being functionally interconnected to a computational means which is programmed to accept ECG data from said ECG monitor and practice the method of steps a.-f., said computational means being functionally interconnected to an output means to enable practice of step g.

11. An ECG system for practicing 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 10, which method further comprises performance of the steps of:

a. providing at least one coordinate system selected from the group consisting of magnitude vs. time, and magnitude vs. frequency;

b. for an ECG cycle portion, performing calculations necessary to plot and display and plotting and displaying normal subject population and subject ECG data for at least one frequency band range, as a function of at least one parameter selected from the group consisting of time and 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

c. observing and interpreting displayed plot(s);

said ECG system computational means being programmed to perform said additional step and cause display thereof via output display means.

12. 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 initial data from ECG cycles from a subject, by providing, selecting and monitoring at least one lead(s) 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 at least one monitored ECG system lead(s), by, for a monitored ECG system lead, 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 at least one ECG system lead(s) 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 ECG cycle(s) from a subject at a later time, by monitoring said at least one lead(s) of an ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) 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, and calculating an average selected ECG cycle portion data set for at least one monitored ECG system lead(s), by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for subject ECG cycle(s), and selecting a plurality of frequency bands, said selected frequency bands being essentially those selected in step b. for said initial subject data, 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 at least one monitored ECG system lead(s), each said data set being a follow-on composite data set of said selected ECG cycle portion for said subject in a monitored lead and selected frequency band range;

e. calculating corresponding representative parameter(s) from resulting composite data sets calculated in steps b. and d., in said selected frequency band ranges for monitored ECG system lead(s), 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 change; 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 m; 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 represenatative 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.

13. A noninvasive method of tracking the cardiac status of a subject utilizing electrocardiography ECG data obtained therefrom as in claim 12, 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.

14. A noninvasive method of tracking cardiac status change in a subject utilizing electrocardiography ECG data obtained therefrom as in claim 12, 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.

15. A noninvasive method of tracking cardiac status of a subject utilizing electrocardiography ECG data obtained therefrom as in claim 12, 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.

16. A method of analyzing stored electrocardiography ECG data of a specific subject, comprising the steps of:

a. obtaining data from ECG cycle(s) of said subject, and from subject(s) identified as normal, then selecting frequency band(s), and separately applying necessary filtering techniques to said data obtained from said subject and from said 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 essentally 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); and

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

17. A method of analyzing stored electrocardiography ECG data of a specific subject as in claim 16, 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); and

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.

18. 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 at least one lead(s) of said 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 at least one monitored ECG system lead(s) by, for a monitored ECG system lead, 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, for a monitored ECG system lead;

c. obtaining data from ECG cycle(s) from a subject, by monitoring at least one lead(s) of said ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) utilized in step a. to obtain data utilized in step b.;

d. selecting some ECG cycle portion, which is essentially that selected in step b., and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s) by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s) obtained from said subject, each said calculated average selected ECG cycle portion data set being a composite data set of said selected ECG cycle portion for said subject, for a monitored ECG system lead;

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

said method further 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 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 two subject representative parameter values, and utilizing said pattern(s) as additional basis for insight to cardiac abnormality; 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.

19. A system for practicing 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 18, which method further comprises performance of the step of applying a confidence level acceptance test to results of comparing specific subject, to corresponding specific normal subject population, representative parameter(s) 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) 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 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 said corresponding specific normal subject population representative parameter.

20. 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 at least one lead(s) of said 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 at least one monitored ECG system lead(s) by, for a monitored ECG system lead, 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, for a monitored ECG system lead;

c. obtaining data from ECG cycle(s) from a subject, by monitoring at least one lead(s) of ECG said system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) utilized in step a. to obtain data utilized in step b.;

d. selecting some ECG cycle portion, which is essentially that selected in step b., and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s) by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for ECG cycle(s) obtained from said subject, each said calculated average selected ECG cycle portion data set being a composite data set of said selected ECG cycle portion for said subject, for a 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., for monitored ECG system lead(s), for, respectively, said normal subject population and said subject;

f. comparing specific ratio(s) of subject to corresponding specific ratio(s) of normal subject population representative parameters, and combining results thereof to arrive at a "score", the magnitude of which "score" results from difference(s) between magnitude(s) of specific corresponding ratio(s) of normal subject population, and ratio(s) of subject representative parameters, which "score" magnitude increases when said difference(s) in magnitude(s) between specific ratio(s) of corresponding normal subject population, and specific 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 the 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 the magnitude(s) of ratio(s) of subject representative parameters are generally progressively less closely matched to the magnitude(s) of ratio(s) of corresponding normal subject population representative parameters;

said method further 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 two ratios of subject representative parameter values, and utilizing said pattern(s) as additional basis for insight to cardiac abnormality; 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.

21. A system for practicing 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 20, which method further comprises performance of the step of applying a confidence level acceptance test to results of comparing specific ratio(s) of subject, to corresponding specific ratio(s) 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 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 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 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 said acceptance parameter for 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.

22. 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 at least one lead(s) 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 at least one monitored ECG system lead(s), by, for a monitored ECG system lead, 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 at least one ECG system lead(s) monitored, 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 ECG cycle(s) from a subject, by monitoring at least one lead(s) of said ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) 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, and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s), by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for subject ECG cycle(s), and 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 at least one monitored ECG system lead(s), each said data set being a composite data set of said selected ECG cycle portion for said subject in a monitored lead and selected frequency band range;

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 monitored ECG system lead(s), 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 "scores" 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 comprising as additonal 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 represenatative 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.

23. A system for practicing 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 22, 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.

24. A system for practicing 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, 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 at least one lead(s) of an ECG system;

b. establishing criteria for, and in line therewith selecting some ECG cycle portion and calculating an average selected ECG cycle portion data set for at least one monitored ECG system lead(s), by, for a monitored ECG system lead, 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 at least one ECG system lead(s) monitored, 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 ECG cycle(s) from a subject, by monitoring at least one lead(s) of an ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) 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, and calculating an average selected ECG cycle portion data set for at least one monitored ECG system lead(s), by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for subject ECG cycle(s), and 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 at least one monitored ECG system lead(s), each said data set being a composite data set of said selected ECG cycle portion for said subject in a monitored lead and selected frequency band range;

e. providing an output display means and performing at least one of the following steps f. and g.;

f. calculating mean and standard deviation representative parameters from at least one resulting composite data set calculated in step b., said mean and standard deviation parameters being from a selected frequency band range for a monitored ECG system lead, and providing a coordinate system consisting of magnitude vs. time on ordinate and abscissa respectively and plotting and displaying on said coordinate system loci consisting of;

25. normal subject population standard deviation bounds located above and below said normal subject population mean, anda corresponding subject data set, then observing differences between normal subject population and subject data plots, with a subject data set falling within the normal subject standard deviation bounds being indicative of a subject properly classified as a cardiac normal, and with a subject data set falling progressively further outside said normal subject standard deviation bounds being indicative of a subject progressively more properly classified as a cardiac abnormal;

g. calculating power spectral density data for at least one resulting composite data set calculated in step b. and for a corresponding resulting composite data set calculated in step d. for a selected frequency band range for a monitored ECG system lead, and providing a coordinate system consisting of magnitude vs. frequency on ordinate and abscissa respectively and plotting and displaying on said coordinate system power spectral density data loci, then observing differences between normal subject population and subject data loci, with closely matched corresponding subject and normal subject population data set power spectral density loci being indicative of a subject properly classified as a cardiac normal and with progressively more mismatched subject and normal subject population data set power spectral density loci being indicative of a subject progressively more properly classified as a cardiac abnormal;

said ECG system comprising ECG lead(s) which monitor electrodes affixed to a subject or member of a normal subject population, and which provide monitored signal(s) to an ECG monitor, said ECG monitor being functionally interconnected to a computational means which is programmed to accept ECG data from said ECG monitor and practice the method of steps a.-e., said computational means being functionally interconnected to an output means to enable practice of steps f. or g.

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

a. obtaining initial data from ECG cycles from a subject by providing, selecting and monitoring at least one lead(s) of said ECG system;

b. establishing criteria for, and in line therewith selecting some ECG cycle portion and calculating an average selected ECG cycle portion data set for at least one monitored ECG system lead(s), by, for a monitored ECG system lead, 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 at least one ECG system lead(s) 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 ECG cycle(s) from a subject at a later time, by monitoring at least one lead(s) of an ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) 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, and calculating an average selected ECG cycle portion data set for at least one monitored ECG system lead(s), by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for subject ECG cycle(s), and selecting a plurality of frequency bands, said selected frequency bands being essentially those selected in step b. for said initial subject data, 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 at least one monitored ECG system lead(s), each said data set being a follow-on composite data set of said selected ECG cycle portion for said subject in a monitored lead and selected frequency band range;

e. providing an output display means and performing at least one of the following steps f. and g.;

f. calculating mean and standard deviation representative parameters from at least one resulting composite data set calculated in step b., said mean and standard deviation parameters being from a selected frequency band range for a monitored ECG system lead, and providing a coordinate system consisting of magnitude vs. time on ordinate and abscissa respectively and plotting and displaying on said coordinate system loci consisting of;

1. initial subject standard deviation bounds located above and below said initial subject data set mean, and

2. a corresponding follow-on subject data set,

then observing differences between initial subject and follow-on subject data plots, with a follow-on subject data set falling within the initial subject data set standard deviation bounds being indicative of a subject properly classified as having not undergone cardiac change, and with a follow-on subject data set falling progressively further outside said initial subject data set standard deviation bounds being indicative of a subject progressively more properly classified as having undergone cardiac change;

g. calculating power spectral densilty data for at least one resulting composite data set calculated in step b. and for a corresponding resulting composite data set calculated in step d. for a selected frequency band range for a monitored ECG system lead, and providing a coordinate system consisting of magnitude vs. frequency on ordinate and abscissa respectively and plotting and displaying on said coordinate system power spectral density data loci, then observing differences between initial subject and follow-on subject data loci, with closely matched corresponding initial subject and follow-on subject data set power spectral density loci being indicative of a subject who has not undergone cardiac change and with progressively more mismatched initial subject and follow-on subject data set power spectral density loci being indicative of a subject progressively more properly classified having undergone cardiac change.

27. An ECG system for practicing a noninvasive method of tracking cardiac status change in a subject utilizing electrocardiography ECG data obtained therefrom, 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 initial data from ECG cycles from a subject by providing, selecting and monitoring at least one lead(s) of said ECG system;

b. establishing criteria for, and in line therewith selecting some ECG cycle portion and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s) by, for a monitored ECG system lead, 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 at least one ECG system lead(s) 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 ECG cycle(s) from a subject at a later time, by monitoring said at least one lead(s) of an ECG system, said ECG system lead(s) monitored being the same as the monitored ECG system lead(s) 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, and calculating an average selected ECG cycle portion data set for said at least one monitored ECG system lead(s), by, for a monitored ECG system lead, a procedure comprising combining corresponding ECG cycle portion data points for said selected ECG cycle portion for subject ECG cycle(s), and selecting a plurality of frequency bands, said selected frequency bands being essentially those selected in step b. for said initial subject data, 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 at least one monitored ECG system lead(s), each said data set being a follow-on composite data set of said selected ECG cycle portion for said subject in a monitored lead and selected frequency band range;

e. providing an output display means and performing at least one of the following steps f. and g.;

f. calculating mean and standard deviation representative parameters from at least one resulting composite data set calculated in step b., said mean and standard deviation parameters being from a selected frequency band range for a monitored ECG system lead, and providing a coordinate system consisting of magnitude vs. time on ordinate and abscissa respectively and plotting and displaying on said coordinate system loci consisting of;

28. initial subject standard deviation bounds located above and below said initial subject data set mean, anda corresponding follow-on subject data set,

then observing differences between initial subject and follow-on subject data plots, with a follow-on subject data set falling within the initial subject data set standard deviation bounds being indicative of a subject properly classified as having not undergone cardiac change, and with a follow-on subject data set falling progressively further outside said initial subject data set standard deviation bounds being indicative of a subject progressively more properly classified as having undergone cardiac change;

g. calculating power spectral density data for at least one resulting composite data set calculated in step b. and for a corresponding resulting composite data set calculated in step d. for a selected frequency band range for a monitored ECG system lead, and providing a coordinate system consisting of magnitude vs. frequency on ordinate and abscissa respectively and plotting and displaying on said coordinate system power spectral density data loci, then observing differences between initial subject and follow-on subject data loci, with closely matched corresponding initial subject and follow-on subject data set power spectral density loci being indicative of a subject who has not undergone cardiac change and with progressively more mismatched initial subject and follow-on subject data set power spectral density loci being indicative of a subject progressively more properly classified having undergone cardiac change;

said ECG system comprising ECG lead(s) which monitor electrodes affixed to a subject or member of a normal subject population, and which provide monitored signal(s) to an ECG monitor, said ECG monitor being functionally interconnected to a computational means which is programmed to accept ECG data from said ECG monitor and practice the method of steps a.-e., said computational means being functionally interconnected to an output means to enable practice of steps f. or g.