Apparatus and method for collecting data useful for determining the parameters of an alert window for timing delivery of etc signals to a heart under varying cardiac conditions

Abstract

Apparatus and method for obtaining from a patient's heart data useful for on-line setting of the parameters of a detection time window in an excitable tissue control device. The method includes applying electrodes to a first cardiac site and a second cardiac site of a patient and electrically connecting the electrodes to a data collecting device. The device is then operated under a plurality of different cardiac conditions to obtain a plurality of different histogram data sets. Each histogram data set represents a cumulative time distribution histogram of cardiac depolarization events detected at the second cardiac site in a plurality of cardiac beats. Each histogram data set is defined by a plurality of histogram parameters having values indicative of the cardiac conditions common to the plurality of cardiac beats used to obtain the histogram data set. The histogram parameters include a sensitivity level parameter representing the sensitivity level used for detecting the cardiac depolarization events of the plurality of cardiac beats at the second cardiac site. Another histogram parameter represents the range of values of the beat to beat time interval for the beats who's data is included in the histogram data set. Another histogram parameter has values indicating if the beats who's data is included in the histogram data set were acquired under conditions in which the delivery of non-excitatory ETC signals substantially affected or did not substantially affect the velocity of propagation of depolarization waves in the myocardium. Another histogram parameter, which may be used in devices having pacing capability has values indicating whether the beats who's data is included in the histogram data set are paced beats or non-paced beats. The histogram data sets are processed for computing a set of data usable for on-line setting of the parameters of a detection time window. This set of data may then be used for operating an implanted or external ETC device operatively connected to the electrodes.