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US4732157A
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Method and apparatus for quantifying beat-to-beat variability in physiologic waveforms
Assignee: Massachusetts Institute of Technology
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Filing: 1986-08-18
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Granted: 1988-03-22
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Expires: 2006-08-18
Abstract
Abstract Myocardial electrical stability is assessed by sampling an ECG waveform at corresponding fiducial locations for a plurality of beats and creating a scatter plot of the i th sample versus the (i- 1)th sample. A parameter λ is determined which minimizes the sum of the total distances of the points of the scatter plot to an equation x(i)= 4λx(i- 1)[ 1-x(i- 1)]. The value of the parameter λ is related to the electrical stability of the heart.
Inventors
- 👤 Daniel T. Kaplan
- 👤 Richard J. Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:08
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/024; A61B5/02405; A61B5/24; A61B5/316; A61B5/318; A61B5/346; A61B5/349; A61B5/361; A61B5/72; A61B5/7271; A61B5/7275; G; G16; G16H; G16H50/00; G16H50/20; G16H50/30
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
60 words
Method for determining cycle-to-cycle alternation in a physiologic waveform comprising: sampling the waveform at corresponding fiducial locations for a plurality of cycles; creating a scatter plot of the ith sample versus the (i-1)th sample; and determining a parameter λ which optimizes the fit of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of λ quantifying the degree of alternation.
Claim 2
Dependent Claim
60 words
Method for determining cycle-to-cycle alternation in a physiologic waveform comprising: sampling the waveform at corresponding fiducial locations for a plurality of cycles; creating a scatter plot of the ith sample versus the (i-1)th sample; and determining a parameter λ which optimizes the fit of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of λ quantifying the degree of alternation.
Claim 3
Dependent Claim
12 words
The method of claim 1 using an iterative method to determine λ.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the physiologic waveform is the ECG.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein the physiologic waveform is a blood pressure waveform.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein the physiologic waveform is a respiratory waveform.
Claim 7
Dependent Claim
20 words
The method of claim 3 wherein the fiducial location is beyond the peak of the QRS complex of the ECG.
Claim 8
Dependent Claim
69 words
Method for assessing susceptibility to ventricular fibrillation comprising: sampling an ECG waveform at corresponding fiducial locations for a plurality of beats; creating a scatter plot of the ith sample versus the (i-1)th sample; and determining a parameter λ which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of the parameter λ being related to the susceptibility of fibrillation.
Claim 9
Dependent Claim
69 words
Method for assessing susceptibility to ventricular fibrillation comprising: sampling an ECG waveform at corresponding fiducial locations for a plurality of beats; creating a scatter plot of the ith sample versus the (i-1)th sample; and determining a parameter λ which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of the parameter λ being related to the susceptibility of fibrillation.
Claim 10
Dependent Claim
18 words
The method of claim 7 wherein a value of λ greater than 0.75 indicates high susceptibility to fibrillation.
Claim 11
Dependent Claim
74 words
Apparatus for determining cycle-to-cycle alternation in a physiologic waveform comprising: means for sampling the waveform at corresponding fiducial locations for a plurality of cycles; means for creating a scatter plot of the ith sample versus the (i-1)th sample; and computing means for determining a parameter λ which minimizes the sum of the total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of λ quantifying the degree of alternation.
Claim 12
Dependent Claim
74 words
Apparatus for determining cycle-to-cycle alternation in a physiologic waveform comprising: means for sampling the waveform at corresponding fiducial locations for a plurality of cycles; means for creating a scatter plot of the ith sample versus the (i-1)th sample; and computing means for determining a parameter λ which minimizes the sum of the total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of λ quantifying the degree of alternation.
Claim 13
Dependent Claim
16 words
The apparatus of claim 9 wherein the computing means utilizes an iterative method to determine λ.
Claim 14
Dependent Claim
12 words
The apparatus of claim 9 wherein the physiologic waveform is the ECG.
Claim 15
Dependent Claim
14 words
The apparatus of claim 9 wherein the physiologic waveform is a blood pressure waveform.
Claim 16
Dependent Claim
13 words
The apparatus of claim 9 wherein the physiologic waveform is a respiratory waveform.
Claim 17
Dependent Claim
20 words
The apparatus of claim 11 wherein the fiducial location is beyond the peak of the QRS complex of the ECG.
Claim 18
Dependent Claim
76 words
Apparatus for assessing susceptibility to ventricular fibrillation comprising: means for sampling an ECG waveform at corresponding fiducial locations for a plurality of beats; means for creating a scatter plot of the ith sample versus the (i-1)th sample; and computing means for determining a parameter λ which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of the parameter λ being related to the susceptability to fibrillation.
Claim 19
Dependent Claim
76 words
Apparatus for assessing susceptibility to ventricular fibrillation comprising: means for sampling an ECG waveform at corresponding fiducial locations for a plurality of beats; means for creating a scatter plot of the ith sample versus the (i-1)th sample; and computing means for determining a parameter λ which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of the parameter λ being related to the susceptability to fibrillation.
Claim 20
Dependent Claim
18 words
The apparatus of claim 15 wherein a value of λ greater than 0.75 indicates high susceptibility to fibrillation.
Claim 21
Dependent Claim
69 words
Method for assessing susceptibility to ventricular fibrillation comprising: sampling a physiologic waveform at corresponding fiducial locations for a plurality of cycles; creating a scatter plot of the ith sample versus the (i-1)th sample; and determining a parameter λ which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of the parameter λ being related to the susceptibility to fibrillation.
Claim 22
Dependent Claim
69 words
Method for assessing susceptibility to ventricular fibrillation comprising: sampling a physiologic waveform at corresponding fiducial locations for a plurality of cycles; creating a scatter plot of the ith sample versus the (i-1)th sample; and determining a parameter λ which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of the parameter λ being related to the susceptibility to fibrillation.
Claim 23
Dependent Claim
76 words
Apparatus for assessing susceptibility to ventricular fibrillation comprising: means for sampling a physiologic waveform at corresponding fiducual locations for a plurality of beats; means for creating a scatter plot of the ith sample versus the (i-1)th sample; and computing means for determining a parameter λ which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of the parameter λ being related to the susceptibility to fibrillation.
Claim 24
Dependent Claim
76 words
Apparatus for assessing susceptibility to ventricular fibrillation comprising: means for sampling a physiologic waveform at corresponding fiducual locations for a plurality of beats; means for creating a scatter plot of the ith sample versus the (i-1)th sample; and computing means for determining a parameter λ which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4λx(i-1)[1-x(i-1)], the value of the parameter λ being related to the susceptibility to fibrillation.
Claim 25
Dependent Claim
65 words
Method for determining cycle-to-cycle alternation in a physiologic waveform comprising: sampling the waveform at corresponding fiducial locations for a plurality of cycles; storing ordered pairs for the ith and (i-1)th samples; and determining a parameter λ which minimizes the sum of the total distances of the points represented by the ordered pairs to an equation x(i)=4λx(-1)[1-x(i-1)], the value of λ quantifying the degree of alternation.
Claim 26
Dependent Claim
65 words
Method for determining cycle-to-cycle alternation in a physiologic waveform comprising: sampling the waveform at corresponding fiducial locations for a plurality of cycles; storing ordered pairs for the ith and (i-1)th samples; and determining a parameter λ which minimizes the sum of the total distances of the points represented by the ordered pairs to an equation x(i)=4λx(-1)[1-x(i-1)], the value of λ quantifying the degree of alternation.
References Cited (Backward Citations)
US4375079A
Cited
US4463425A
Cited
US4453226A
Cited
US4543632A
Cited
US4661913A
Cited
US4633400A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-22 | 1991-09-21 | 1992-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-22 | 1995-09-21 | 1996-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-22 | 1999-09-21 | 2000-03-22 | $7700.00 | Window Closed / Lapsed |