Abstract: A device for detecting cardiac ischemia is disclosed. The device includes a processor that is configured to distinguish between two different heart beats types such as left bundle branch block beats and normal sinus beats. The processor applies different ischemia tests to the two different beat types, and generates alert when it detects ischemia.

Abstract: A system for the detection of cardiac events occurring in a human patient is provided. At least two electrodes are included in the system for obtaining an electrical signal from a patient's heart. An electrical signal processor is electrically coupled to the electrodes for processing the electrical signal and a patient alarm means is further provided and electrically coupled to the electrical signal processor. The electrical signal is acquired in the form of electrogram segments, which are categorized according to heart rate, ST segment shift and type heart rhythm (normal or abnormal). Baseline electrogram segments are tracked over time.

Abstract: A heart rate monitor generates an ST deviation time series by employing a recursive filter that is preferably an exponential average filter whose output is a weighted sum of the then existing ST time series value and current ST deviation values of analyzable beats. Beats are detected in segments of data. ST deviation is measured for analyzable beats. The ST deviation time series is updated only if certain criteria are met. A first criterion for updating the time series is that at least half of the beats within a segment must be normal sinus rhythm beats. A second criterion for updating the time series is that (i) the average RR interval of the segment is between ¾ and 1.5 times the average RR interval of the previous segment; or (ii) both (a) the number of abnormal beats in the current segment is less than 2, and (b) the number of premature ventricular contractions within the current segment is less than 2.

Abstract: A heart monitor is disclosed. The monitor computes ST segment deviations and stores the results in heart rate based histograms. Periodically, the monitor analyzes the histogram data to determine heart rate dependent acute ischemia detection thresholds. If the statistical distribution associated with a heart rate range is insufficient, the threshold for that heart rate range is set as a function of the threshold for a neighboring heart rate range. Thresholds are also increased for heart rate ranges associated with statistical distributions that are sufficient but that have a relatively small number of entries.

Abstract: A heart monitor is disclosed. The monitor computes ST segment deviations and stores the results in heart rate based histograms. Periodically, the monitor analyzes the histogram data to determine a normal range of ST deviation for a particular heart rate range. The monitor computes heart rate dependent ischemia detection thresholds based on the upper and lower boundaries of the normal range.

Abstract: An acute ischemia monitor is disclosed. The monitor, which includes an analog to digital convertor and a processor that performs beat detection, monitors the time course of a heart signal parameter, namely ST segment deviation, computed from an electrocardiogram. The device stores ST deviation statistics for multiple leads. For each lead, upper and lower ST deviation boundaries are computed. For each lead, current ST deviation values are compared with the statistical values to determine a metric indicative of the degree of abnormality of a current ST deviation value. The metric is equal to the difference between the current ST deviation value and the upper or lower boundary, normalized according to the dispersion of the ST deviation. Metrics from different leads are summed and compared to a threshold to determine whether the combined metric is indicative of a cardiac event.

Abstract: A heart monitor is disclosed. The monitor computes ST segment deviations and stores the results in heart rate based histograms. Periodically, the monitor analyzes the histogram data to determine a median value of ST deviation. Subsequently, beats are excluded from the computation of the time series if their ST deviations both varies too far from the long term median value and varies too far from the then current time series value.

Abstract: A device for detecting cardiac ischemia is disclosed. The device includes a processor that is configured to distinguish between two different heart beats types such as ventricularly paced beats and supraventricular beats. The processor applies different ischemia tests to the two different beat types, and generates alert when it detects ischemia.

Abstract: A system for the detection of cardiac events occurring in a human patient is provided. At least two electrodes are included in the system for obtaining an electrical signal from a patient's heart. An electrical signal processor is electrically coupled to the electrodes for processing the electrical signal and a patient alarm means is further provided and electrically coupled to the electrical signal processor. The electrical signal is acquired in the form of electrogram segments, which are categorized according to heart rate, ST segment shift and type heart rhythm (normal or abnormal). Baseline electrogram segments are tracked over time.

Abstract: A heart monitor is disclosed. The monitor computes ST segment deviations and stores the results in heart rate based histograms. Periodically, the monitor analyzes the histogram data to determine heart rate dependent acute ischemia detection thresholds. If the statistical distribution associated with a heart rate range is insufficient, the threshold for that heart rate range is set as a function of the threshold for a neighboring heart rate range. Thresholds are also increased for heart rate ranges associated with statistical distributions that are sufficient but that have a relatively small number of entries.

Abstract: An acute ischemia monitor is disclosed. The monitor, which includes an analog to digital convertor and a processor that performs beat detection, monitors the time course of a heart signal parameter, namely ST segment deviation, computed from an electrocardiogram. The device stores ST deviation statistics for multiple leads. For each lead, upper and lower ST deviation boundaries are computed. For each lead, current ST deviation values are compared with the statistical values to determine a metric indicative of the degree of abnormality of a current ST deviation value. The metric is equal to the difference between the current ST deviation value and the upper or lower boundary, normalized according to the dispersion of the ST deviation. Metrics from different leads are summed and compared to a threshold to determine whether the combined metric is indicative of a cardiac event.

Abstract: A heart monitor is disclosed. The monitor computes ST segment deviations and stores the results in heart rate based histograms. Periodically, the monitor analyzes the histogram data to determine a normal range of ST deviation for a particular heart rate range. The monitor computes heart rate dependent ischemia detection thresholds based on the upper and lower boundaries of the normal range.

Abstract: A heart monitor is disclosed. The monitor computes ST segment deviations and stores the results in heart rate based histograms. Periodically, the monitor analyzes the histogram data to determine a median value of ST deviation. Subsequently, beats are excluded from the computation of the time series if their ST deviations both varies too far from the long term median value and varies too far from the then current time series value.

Abstract: A system for the detection of cardiac events occurring in a human patient is provided. At least two electrodes are included in the system for obtaining an electrical signal from a patient's heart. An electrical signal processor is electrically coupled to the electrodes for processing the electrical signal and applying tests to determine whether a cardiac event has occurred. When the processor detects some types of changes in heart rate, event detection is altered or suspended for a period of time.

Abstract: A device for detecting cardiac ischemia is disclosed. The device includes a processor that is configured to distinguish between two different heart beats types such as left bundle branch block beats and normal sinus beats. The processor applies different ischemia tests to the two different beat types, and generates alert when it detects ischemia.

Abstract: A device for detecting a cardiac event is disclosed. Detection of an event is based on a test applied to a parameter whose value varies according to heart rate. Both the parameter value and heart rate (RR interval) are filtered with an exponential average filter. From these filtered values, the average change in the parameter and the RR interval are also computed with an exponential average filter. Before computing the average change in the parameter, large changes in the parameter over short times, which may be caused by body position shifts, are attenuated are removed, so that the average change represents an average of small/smooth changes in the parameter's value that are characteristic of acute ischemia, one of the cardiac events that may be detected. The test to detect the cardiac event depends on the heart rate, the difference between the parameter's value and its upper and lower normal values, and its average change over time, adjusted for heart rate changes.

Abstract: A heart rate monitor is disclosed. The monitor generates an ST deviation time series by employing a recursive filter that is preferably an exponential average filter whose output is a weighted sum of the then existing ST time series value and current ST deviation values of analyzable beats, seats are detected in segments of data. ST deviation is measured for analyzable beats. The ST deviation time series is updated only if certain criteria are met. A first criterion for updating the time series is that at least half of the beats within a segment must be normal sinus rhythm beats: A second criterion for updating the time series is that (i) the average RR interval of the segment is between ¾ and 1.5 times the average RR interval of the previous segment; or (ii) both (a) the number of abnormal beats in the current segment is less than 2, and (b) the number of premature ventricular contractions within the current segment is less than 2.

Abstract: A system for the detection of cardiac events occurring in a human patient is provided. At least two electrodes are included in the system for obtaining an electrical signal from a patient's heart. An electrical signal processor is electrically coupled to the electrodes for processing the electrical signal and a patient alarm means is further provided and electrically coupled to the electrical signal processor. The electrical signal is acquired in the form of electrogram segments, which are categorized according to heart rate, ST segment shift and type heart rhythm (normal or abnormal). Baseline electrogram segments are tracked over time.

Abstract: Disclosed are systems and methods for detecting the QRS portion of an electrocardiogram and also for detect QRS onset/offset points. QRS complexes are identified by testing selected waveform samples to determine if they are in a high curvature region. If a region passes the high curvature test, a verification test is applied to adjacent samples to confirm that the region is within a QRS complex. The search for a QRS onset point begins at an adaptive distance from this region. The curvature of selected regions ahead in the search direction is examined. The search moves past all such high curvature regions. The onset point is then located by searching for a region that is “flat” in either of two senses. First, a region may be locally flat (i.e. small first derivative) in an absolute sense. Second, a region is flat in a relative that further movement away from the interior of the QRS (e.g. toward “earlier” samples) does not result in a significant change in the value of the first derivative.

Abstract: A system for the detection of cardiac events occurring in a human patient is provided. At least two electrodes are included in the system for obtaining an electrical signal from a patient's heart. An electrical signal processor is electrically coupled to the electrodes for processing the electrical signal and applying tests to determine whether a cardiac event has occurred. When the processor detects some types of changes in heart rate, event detection is altered or suspended for a period of time.