US4947857A
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US
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Method and apparatus for analyzing and interpreting electrocardiograms using spectro-temporal mapping
Assignee: ARRHYTHMIA RESEARCH TECHNOLOGY Inc
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Filing: 1989-02-01
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Granted: 1990-08-14
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Expires: 2009-02-01
Abstract
Abstract Method and apparatus for analyzing ECG signal data for diagnostic purposes by performing an incrementally moving, short window FFT analysis to produce a set of spectral templates representative of the spectral frequency content of the ECG at each window position. The spectral templates may be displayed as a representation of a three dimensional surface or mathematically analyzed. The changes in the shape of the templates or surface with time represent a change in the spectrum, which are shown to be an indication of abnormalities in the heart.
Inventors
- 👤 David E. Albert
- 👤 Paul Lander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:46
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/72; A61B5/7235; A61B5/7253; A61B5/24; A61B5/316; A61B5/318; A61B5/346; A61B5/349; A61B5/35; A61B5/7257
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
103 words
The system for evaluating a electrocardiogram (ECG) of a patient which comprises: means for calculating from the ECG and storing digital data defining a three dimensional graphic surface representative of the spectral frequency of the ECG in which the first axis is the time domain of the ECG, the second axis is the frequency domain, and the third axis is representative of the amplitude or power domain; means for displaying the surface in a three dimensional visually discernible presentation; and means for producing visually discernible indicia on the surface selected to reveal predetermined characteristics of the HRECG useful in medically evaluating the patient.
Claim 2
Independent Claim
103 words
The system for evaluating a electrocardiogram (ECG) of a patient which comprises: means for calculating from the ECG and storing digital data defining a three dimensional graphic surface representative of the spectral frequency of the ECG in which the first axis is the time domain of the ECG, the second axis is the frequency domain, and the third axis is representative of the amplitude or power domain; means for displaying the surface in a three dimensional visually discernible presentation; and means for producing visually discernible indicia on the surface selected to reveal predetermined characteristics of the HRECG useful in medically evaluating the patient.
Claim 3
Dependent Claim
21 words
The system of claim 1 wherein the means for displaying the surface displays a set of templates defined by the surface.
Claim 4
Dependent Claim
16 words
The system of claim 2 wherein the set of templates is a set of spectral templates.
Claim 5
Independent Claim
39 words
The system of claims 2 or 3 further comprising means for producing a measure of degree of correlation of relative shapes of at least two templates of the set spacially related one to the other in a selected manner.
Claim 6
Dependent Claim
36 words
The system of claim 4 wherein the degree of correlation is determined for adjacent templates of a selected set of templates and presented as a visual image related to the time domain axis of the surface.
Claim 7
Dependent Claim
23 words
The system of claim 5 wherein the degree of correlation is a correlation factor comprising a discrete value plotted with respect to time.
Claim 8
Dependent Claim
34 words
The system of claim 6 wherein the degree of correlation is a residual area template for each template pair and the residual area templates are displayed as a set in a three dimensional image.
Claim 9
Dependent Claim
46 words
The system of claim 1 or 2 further comprising means for producing a value with respect to the time domain representative of a selected attribute of the frequency spectrum at the corresponding point in time and displaying a set of such values with respect to time.
Claim 10
Dependent Claim
14 words
The system of claim 8 wherein the selected attribute is the spectral edge frequency.
Claim 11
Dependent Claim
15 words
The system of claim 8 wherein the selected attribute is the mean or median frequency.
Claim 12
Independent Claim
31 words
The system of claims 1, 2 or 3 further comprising means for computing a value representative of the total area under the surface for a selected point on the time axis.
Claim 13
Dependent Claim
26 words
The system of claim 11 further comprising means for computing a value representative of the total volume defined by the surface and selected limits of time.
Claim 14
Independent Claim
35 words
The system of claims 11 or 12 further including means for computing a series of values and selecting the first occurring value above a predetermined value as a reference point in time of the ECG.
Claim 15
Independent Claim
26 words
The system as in one of claims 1-13 further comprising means for selectively, under operator control, rotating the axes of the visual presentation of the surface.
Claim 16
Dependent Claim
17 words
The system of claim 14 further comprising means for, under operator control, selecting different visually discernible indicia.
Claim 17
Dependent Claim
30 words
The system of claim 15 wherein the means under operator control include means for selectively displaying data points of a surface lying in a plane passing through said graphic surface.
Claim 18
Dependent Claim
28 words
The system of claim 15 or 16 wherein the means under operator control includes means for selecting lines indicating data points on, or equidistance from, a selected plane.
Claim 19
Dependent Claim
36 words
The system of claim 17 further comprising means for performing computational manipulation of the data defining the surface lying in a plane passing through said graphic surface to determine preselected values of interest of the data.
Claim 20
Dependent Claim
33 words
The system of claim 17 or 18 further comprising indicia means under control of the operator for selecting points on the display for inputting data to be used in computational manipulation of data.
Claim 21
Dependent Claim
36 words
The system of claim 18 wherein the preselected values include values indicative of onset and offset of the QRS segment of the HRECG and provide a measure of the overall time duration of the QRS segment.
Claim 22
Dependent Claim
29 words
The system of claim 20 wherein the preselected values include, for each time increment, a value equal to a predetermined percent of total spectrum power within predetermined frequency limits.
Claim 23
Dependent Claim
61 words
The system of claim 18 wherein the preselected values include at least one set of contour templates, each contour template being all values of a surface having the same constant predetermined value for one of the axes, and each successive template of the set having a predetermined value which is incrementally greater than the said predetermined value of the preceding template.
Claim 24
Dependent Claim
14 words
The system of claim 22 wherein each contour template has a constant time value.
Claim 25
Dependent Claim
14 words
The system of claim 22 wherein each contour template has a constant frequency value.
Claim 26
Dependent Claim
14 words
The system of claim 22 wherein each contour template has a constant power value.
Claim 27
Independent Claim
55 words
The system as in one of claims 22-25 further comprising means for progressively comparing each template of at least a portion of the set of templates to the next adjacent template of the set to produce a correlation function and displaying the correlation function with respect to the respective constant values of the template set.
Claim 28
Dependent Claim
36 words
The system of claim 26 further comprising means for normalizing each successive template with respect to the adjacent template with which it is correlated such that the correlation value is primarily related to the templates shape.
Claim 29
Dependent Claim
27 words
The system of claim 26 or 27 further comprising means for automatically selecting predetermined events based on the first occurrence of a correlation value of predetermined magnitude.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-13 | 1994-02-12 | 1994-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-13 | 1998-02-12 | 1998-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-13 | 2002-02-12 | 2002-08-14 | $7700.00 | Window Closed / Lapsed |