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US5555889A
Expired / Lapsed
US
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Methods for detecting propensity fibrillation
Assignee: Cedars-Sinai Medical Center
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Filing: 1994-02-04
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Granted: 1996-09-17
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Expires: 2014-02-04
Abstract
Abstract A method for detecting a heart disorder comprises examination of a phase-plane plot (PPP) of a patient electrocardiogram (EKG). The PPP's degree of deterministic chaos may be measured by a processor. Analysis of the PPP may indicate a propensity for fibrillation, that is, indicate both the risk of fibrillation and its actual onset (cases where risk is 100 percent). A second method for detecting a heart disorder comprises examination of a frequency-domain transform (such as an FFT) of a patient EKG. An automatic defibrillating device may comprise means for delivering a variable shock, the size of which is determined at least in part by the FFT's peak energy. A method for detecting drug toxicity comprises examination of a parameter time constant for an action-potential duration (APD) restitution curve which is constructed for the patient.
Inventors
- 👤 Hrayr S. Karagueuzian
- 👤 George A. Diamond
- 👤 Steven S. Khan
- 👤 Timothy A. Denton
- 👤 Steven Evans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:56
CPC Classifications
A; A61; A61N; A61N1/00; A61N1/18; A61N1/32; A61N1/38; A61N1/385; A61N1/39; A61N1/3925; A61B; A61B5/00; A61B5/72; A61B5/7235; A61B5/7239
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
115 words
A method for detecting a propensity for ventricular fibrillation comprising the steps of sensing an EKG signal; constructing a phase plane plot of said EKG signal; computing the fractal dimension of said phase plane plot by a) superimposing a rectilinear grid on said phase plane plot; b) counting the number of boxes which are cut by the PPP's trace; c) counting the number of boxes in the grid; d) calculating the fractal dimension, K, according to the equation ln (# of boxes cut)=K* ln (# of boxes in grid); e) determining whether K falls within the range of 3 to about 7; registering the propensity for ventricular fibrillation if the value is within this range.
Claim 2
Independent Claim
115 words
A method for detecting a propensity for ventricular fibrillation comprising the steps of sensing an EKG signal; constructing a phase plane plot of said EKG signal; computing the fractal dimension of said phase plane plot by a) superimposing a rectilinear grid on said phase plane plot; b) counting the number of boxes which are cut by the PPP's trace; c) counting the number of boxes in the grid; d) calculating the fractal dimension, K, according to the equation ln (# of boxes cut)=K* ln (# of boxes in grid); e) determining whether K falls within the range of 3 to about 7; registering the propensity for ventricular fibrillation if the value is within this range.
Claim 3
Independent Claim
53 words
A method for detecting a propensity for ventricular fibrillation comprising the steps of sensing an EKG signal; constructing a phase plane of said EKG signal; computing the correlation dimension using a modified Grassberger-Procaccia algorithm; determining whether the correlation dimension of the system converges; registering the propensity for ventricular fibrillation if convergence is present.
Claim 4
Independent Claim
53 words
A method for detecting a propensity for ventricular fibrillation comprising the steps of sensing an EKG signal; constructing a phase plane of said EKG signal; computing the correlation dimension using a modified Grassberger-Procaccia algorithm; determining whether the correlation dimension of the system converges; registering the propensity for ventricular fibrillation if convergence is present.
Claim 5
Independent Claim
42 words
A method for detecting a propensity for ventricular fibrillation comprising the steps of sensing an EKG signal; constructing a phase plane plot of said EKG signal; computing the fractal dimension of the phase plane plot; and registering the propensity for ventricular fibrillation.
Claim 6
Independent Claim
42 words
A method for detecting a propensity for ventricular fibrillation comprising the steps of sensing an EKG signal; constructing a phase plane plot of said EKG signal; computing the fractal dimension of the phase plane plot; and registering the propensity for ventricular fibrillation.
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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) | 1999-09-17 | 2000-03-18 | 2000-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-17 | 2004-03-18 | 2004-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-17 | 2008-03-18 | 2008-09-17 | $7700.00 | Window Closed / Lapsed |