Medical instrument for noninvasive measurement of cardiovascular characteristics
Method and apparatus for assessing myocardial electrical stability
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Apparatus and method for detecting and processing impedance rheogram
Non-invasive dynamic tracking of cardiac vulnerability by analysis of T-wave alternans
Cardiac analyzer with REM sleep detection
Electrocardiographic method and device
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ApplicationNo. 722351 filed on 09/27/1996
US Classes:600/515, Detecting arrhythmia128/901, SUPPRESSION OF NOISE IN ELECTRIC SIGNAL600/513Detecting heartbeat electric signal and diverse cardiovascular characteristic
ExaminersPrimary: Kamm, William E.
Assistant: Schaetzle, Kennedy J.
Attorney, Agent or Firm
International ClassA61B 005/040.2
AbstractAn intramyocardial activity detector for detecting repeating patterns of irregular intramyocardial Wenckebach activity in the heart of a patient is provided. The apparatus includes a mechanism measuring electrocardiogram (ECG) signals from the body, a mechanism for measuring respiratory signals from the body, and a processor electrically associated with the two mechanisms means for measuring to determine the presence of intramyocardial Wenckebach activity of two or more phases. The processor calculates Wenckebach basis function strengths that indicate the presence of voltage in the measured ECG signals caused by repeating patterns of irregular intramyocardial Wenckebach activity via a relationship that describes the measured ECG signals as comprising Wenckebach input being additive to respiratory interference. In this relationship a nonsingular Wenckebach matrix W representing Wenckebach basis functions reflecting Wenckebach phases and a nonsingular interference matrix R act on the ECG signals to extract the Wenckebach input. The nonsingular interference matrix R based on the respiratory signals and the ECG signals of the patient represents how the measured ECG signals are related to the phases of the respiration. The Wenckebach basis function strengths are calculated in terms of the measured ECG signals, the nonsingular Wenckebach matrix W, and the nonsingular interference matrix R.