The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 1993
Filed:
Sep. 22, 1992
Richard L Verrier, Bethesda, MD (US);
Bruce D Nearing, Rockville, MD (US);
Georgetown University, Washington, DC (US);
Abstract
A method and apparatus for the non-invasive, dynamic tracking and diagnosing of cardiac vulnerability to ventricular fibrillation are disclosed. T-wave alternans and heart rate variability are simultaneously evaluated. T-wave alternation is an absolute predictor of cardiac electrical instability. Heart rate variability is a measure of autonomic influence, a major factor in triggering cardiac arrythmias. By simultaneously analyzing both phenomena, the extent and cause of cardiac vulnerability can be assessed. The method includes the following steps. An ECG signal is sensed from a heart. The T-wave portions of the ECG signal are analyzed to estimate an amplitude of beat-to-beat alternation. The amplitude of beat-to-beat alternation represents cardiac electrical instability. The R-R intervals are analyzed to estimate a magnitude of a high frequency component of heart rate variability and to estimate a magnitude of a low frequency component of heart rate variability. The high frequency component indicates parasympathetic activity. The low frequency component indicates combined sympathetic activity and parasympathetic activity. The amplitude of beat-to-beat alternation, the high frequency component of heart rate variability, and the low frequency component of heart rate variability are simultaneously analyzed to diagnose cardiac electrical instability.