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US5365426A
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Advanced signal processing methodology for the detection, localization and quantification of acute myocardial ischemia
Assignee: University of Maryland, College Park
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Filing: 1990-09-21
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Granted: 1994-11-15
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Expires: 2010-09-21
Abstract
Abstract Monopolar ECG signals are converted into the multichannel spectrum and autocorrelation domains, and different decision variables are identified from the autospectra. Statistically validated threshold levels are used for comparison with the decision variables to determine the probability of normal and ischemic conditions.
Inventors
- 👤 John H. Siegel
- 👤 Chrysostomos L. Nikias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:36
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/316; A61B5/318; A61B5/346; A61B5/349; A61B5/25; A61B5/279; A61B5/28; A61B5/283; A61B5/287; A61B5/72; A61B5/7235; A61B5/7246; Y; Y10; Y10S; Y10S128/00; Y10S128/92
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
89 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from said ECG sensor; generating a decision variable from said ECG signal; comparing said decision variable to a histogram of previously obtained sensor signal data to obtain a myocardial ischemia quantification index corresponding to a probability of ischemia; and comparing said quantification index to a selected value to determine the presence of myocardial ischemia.
Claim 2
Independent Claim
89 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from said ECG sensor; generating a decision variable from said ECG signal; comparing said decision variable to a histogram of previously obtained sensor signal data to obtain a myocardial ischemia quantification index corresponding to a probability of ischemia; and comparing said quantification index to a selected value to determine the presence of myocardial ischemia.
Claim 3
Dependent Claim
32 words
A method as defined in claim 1, wherein said generating step comprises converting said ECG signal to the spectrum domain and determining the peak frequency of the converted signal as said variable.
Claim 4
Independent Claim
101 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from said ECG sensor; generating a plurality of decision variables from said ECG signal; comparing said decision variables to at least one histogram of previously obtained sensor signal data to obtain at least one myocardial ischemia quantification index corresponding to a quantification probability of ischemia based on said comparison results; and comparing said quantification index to a selected value to determine the presence of myocardial ischemia.
Claim 5
Independent Claim
101 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from said ECG sensor; generating a plurality of decision variables from said ECG signal; comparing said decision variables to at least one histogram of previously obtained sensor signal data to obtain at least one myocardial ischemia quantification index corresponding to a quantification probability of ischemia based on said comparison results; and comparing said quantification index to a selected value to determine the presence of myocardial ischemia.
Claim 6
Independent Claim
103 words
A method of detecting the existence of muscle dysfunction from a unipolar signal X(n); n=0,1 . . ., N, representing activation of said muscle, where N is an integer, said method comprising the steps of: providing an ECG sensor; detecting said unipolar signal from said muscle activation signal sensor; generating a decision variable from said unipolar signal; comparing said decision variable to a threshold value of said decision variable to obtain a muscular dysfunction quantification index corresponding to a quantification probability of the existence of muscle dysfunction; and comparing said quantification index to a selected value to determine the presence of muscle dysfunction.
Claim 7
Independent Claim
103 words
A method of detecting the existence of muscle dysfunction from a unipolar signal X(n); n=0,1 . . ., N, representing activation of said muscle, where N is an integer, said method comprising the steps of: providing an ECG sensor; detecting said unipolar signal from said muscle activation signal sensor; generating a decision variable from said unipolar signal; comparing said decision variable to a threshold value of said decision variable to obtain a muscular dysfunction quantification index corresponding to a quantification probability of the existence of muscle dysfunction; and comparing said quantification index to a selected value to determine the presence of muscle dysfunction.
Claim 8
Dependent Claim
26 words
A method as defined in claim 4, further comprising determining a degree of said dysfunction based on the comparison of said quantification index to said value.
Claim 9
Dependent Claim
14 words
A method as defined in claim 5, wherein said muscle dysfunction is myocardial ischemia.
Claim 10
Dependent Claim
14 words
A method as defined in claim 4, wherein said muscle dysfunction is myocardial ischemia.
Claim 11
Dependent Claim
14 words
A method as defined in claim 7, wherein said histogram has a non-Gaussian distribution.
Claim 12
Independent Claim
101 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from an ECG sensor; generating a decision variable from said ECG signal; generating a histogram from a plurality of preliminary ECG signals corresponding to both normal and ischemic conditions; comparing said decision variable to said histogram to obtain a myocardial ischemia quantification index corresponding to a quantification probability of ischemia; and comparing said quantification index to a selected value to determine the presence of myocardial ischemia.
Claim 13
Independent Claim
101 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from an ECG sensor; generating a decision variable from said ECG signal; generating a histogram from a plurality of preliminary ECG signals corresponding to both normal and ischemic conditions; comparing said decision variable to said histogram to obtain a myocardial ischemia quantification index corresponding to a quantification probability of ischemia; and comparing said quantification index to a selected value to determine the presence of myocardial ischemia.
Claim 14
Independent Claim
115 words
A method of detecting the existence of muscle dysfunction from a unipolar signal X(n); n=0,1, . . . , N, representing activation of said muscle, where N is an integer, said method comprising the steps of: providing an ECG sensor; detecting said unipolar signal from said muscle activation sensor; generating a histogram from a plurality of preliminary unipolar signals corresponding to both normal and dysfunctional conditions; generating a decision variable from said unipolar signal; comparing said decision variable to said histogram to obtain a muscular dysfunction quantification index corresponding to a quantification probability of the existence of muscular dysfunction; and comparing said quantification index to a selected value to determine the existence of muscle dysfunction.
Claim 15
Independent Claim
115 words
A method of detecting the existence of muscle dysfunction from a unipolar signal X(n); n=0,1, . . . , N, representing activation of said muscle, where N is an integer, said method comprising the steps of: providing an ECG sensor; detecting said unipolar signal from said muscle activation sensor; generating a histogram from a plurality of preliminary unipolar signals corresponding to both normal and dysfunctional conditions; generating a decision variable from said unipolar signal; comparing said decision variable to said histogram to obtain a muscular dysfunction quantification index corresponding to a quantification probability of the existence of muscular dysfunction; and comparing said quantification index to a selected value to determine the existence of muscle dysfunction.
Claim 16
Independent Claim
104 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from an ECG sensor; generating a decision variable from said ECG signal; selecting a threshold value for said decision variable corresponding to a probability of correctly detecting myocardial ischemia when myocardial ischemia is present; comparing said decision variable to said threshold value of said decision variable to obtain comparison results; and determining a myocardial ischemia quantification index corresponding to a quantification probability of ischemia based on said comparison results.
Claim 17
Independent Claim
104 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from an ECG sensor; generating a decision variable from said ECG signal; selecting a threshold value for said decision variable corresponding to a probability of correctly detecting myocardial ischemia when myocardial ischemia is present; comparing said decision variable to said threshold value of said decision variable to obtain comparison results; and determining a myocardial ischemia quantification index corresponding to a quantification probability of ischemia based on said comparison results.
Claim 18
Dependent Claim
32 words
A method as defined in claim 11, wherein said step of selecting a threshold value comprises selecting said threshold value in accordance with a histogram of previous values of said decision variable.
Claim 19
Independent Claim
116 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from said ECG sensor; generating a plurality of decision variables from said ECG signal; combining said decision variables to form a combined decision variable in a multivariate probability space; comparing said combined decision variable to a histogram of a plurality of combined decision variables generated from previously obtained sensor signal data to obtain a myocardial ischemia quantification index corresponding to a quantification probability of ischemia; and comparing said quantification index to a selected value to determine the existence of myocardial ischemia.
Claim 20
Independent Claim
116 words
A method of detecting myocardial ischemia from a time-domain ECG signal X(n); n=0,1, . . . , N, where N is an integer, comprising the steps of: providing an ECG sensor; detecting said ECG signal from said ECG sensor; generating a plurality of decision variables from said ECG signal; combining said decision variables to form a combined decision variable in a multivariate probability space; comparing said combined decision variable to a histogram of a plurality of combined decision variables generated from previously obtained sensor signal data to obtain a myocardial ischemia quantification index corresponding to a quantification probability of ischemia; and comparing said quantification index to a selected value to determine the existence of myocardial ischemia.
Claim 21
Independent Claim
120 words
A method of detecting the existence of muscle dysfunction from a unipolar signal X(n); n=0,1, . . . , N, representing activation of said muscle, where N is an integer, said method comprising the steps of: providing a muscle activation signal sensor; detecting said unipolar signal from said muscle activation sensor; generating a decision variable from said unipolar signal; selecting a threshold value for said decision variable corresponding to a probability of correctly detecting myocardial ischemia when myocardial ischemia is present; comparing said decision variable to said threshold value of said decision variable to obtain comparison results; and determining a muscular dysfunction quantification index corresponding to a quantification probability of the existence of muscle dysfunction based on said comparison results.
Claim 22
Independent Claim
120 words
A method of detecting the existence of muscle dysfunction from a unipolar signal X(n); n=0,1, . . . , N, representing activation of said muscle, where N is an integer, said method comprising the steps of: providing a muscle activation signal sensor; detecting said unipolar signal from said muscle activation sensor; generating a decision variable from said unipolar signal; selecting a threshold value for said decision variable corresponding to a probability of correctly detecting myocardial ischemia when myocardial ischemia is present; comparing said decision variable to said threshold value of said decision variable to obtain comparison results; and determining a muscular dysfunction quantification index corresponding to a quantification probability of the existence of muscle dysfunction based on said comparison results.
References Cited (Backward Citations)
US4930075A
Cited
US4989610A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-11-14 | 1998-05-16 | 1998-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-14 | 2002-05-16 | 2002-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-14 | 2006-05-16 | 2006-11-15 | $7700.00 | Window Closed / Lapsed |