Abstract: A device for detecting cardiac ischemia is disclosed. The device includes a processor that is configured to operate in three different modes according to relative frequency of different beat types. If beats of a first beat type, such as ventricularly paced beats, are predominant, the processor ignores other beat types and performs ischemia detection only on ventricularly paced beats. Conversely, if beats of a second beat type, such as sinus or atrially paced beats, are predominant, the processor ignores ventricularly paced beats and performs ischemia detection only on sinus or atrially paced beats. If there is a mixture of beat types such that neither predominates, the processor performs ischemia detection on both beat types.

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 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 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: Alarm tests are disclosed which use alarm test signals to assess alarms provided by medical devices. Especially relevant are implanted devices that monitor cardiac activity and provide notification in response to medically relevant events. Alarm tests can occur periodically, or in response to a patient, doctor, or remote party initiating the alarm test. Alarm tests can also occur during the actual alarms issued to detected medical events. Alarm tests lead to pass or fail results, which in turn may cause operations to contingently occur. Alarm test failure in the auditory, visual, or tactile modality, may cause an alternatively defined alarm signal to be used as back-up. Alarm test logs can store alarm test results, including quantification of the measured alarm signal. Rapid alarm tests are described, as are various methods of accurately measuring characteristics of the test signal in ambulatory patients, which are especially relevant to a vibration alarm.

Abstract: Disclosed is a system for the detection of cardiac events that includes an implanted device called a cardiosaver, a physician's programmer and an external alarm system. The system is designed to provide early detection of cardiac events such as acute myocardial infarction or exercise induced myocardial ischemia caused by an increased heart rate or exertion. The system can also alert the patient with a less urgent alarm if a heart arrhythmia is detected. Using different algorithms, the cardiosaver can detect a change in the patient's electrogram that is indicative of a cardiac event within five minutes after it occurs and then automatically warn the patient that the event is occurring. To provide this warning, the system includes an internal alarm sub-system (internal alarm means) within the cardiosaver and/or an external alarm system (external alarm means) which are activated after the ST segment of the electrogram exceeds a preset threshold.

Abstract: A physician's programmer for an implantable device is disclosed. The programmer includes a receiver for receiving wireless transmission data from the implantable heart monitor. A processor is configured to extract from the wireless transmission data ST-deviation histogram data as a function of heart rate. The histogram data for a particular heart rate range is shown on a display in the form of a bar chart. The histogram data for a plurality of heart rate ranges is shown in the form of a chart with multiple line plots.

Abstract: A system for cardiac event detection over varying time scales includes implanted electrical leads forming a portion of an implanted cardiotracker and external equipment including external alarm mechanisms and a physicians programmer. The cardiac event detection system monitors the degradation of a patient's cardiovascular condition from one or more causes. A processor computes the electrical signals of a heart signal parameter's average value over a time period for a multiplicity of heart rate ranges. The electrical signals are stored and information transmitted to external equipment.

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 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: 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 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: Disclosed is a system having an implanted component and external component which are configured to provide a test of wireless communication in order to assess the success or failure of such communication and to store attributes related to such test in a memory log. To provide the communication test the implantable and external components can attempt wireless communication according to communication test parameters which relate to number of times to retry communication, duration of sending communication test signals, durations of waiting for communication test signals and the schedule of the communication tests. The schedule of tests may be period or may change over time in order to become more or less frequency according to a programmable schedule that may also decrease if the communication tests are successful and indicate patient compliance in keeping the external components close by.

Abstract: Disclosed is a system for the detection of cardiac events (a guardian system) that includes an implanted device called a cardiosaver, a physician's programmer and an external alarm system. The system is designed to provide early detection of cardiac events such as acute myocardial infarction or exercise induced myocardial ischemia caused by an increased heart rate or exertion. The system can also alert the patient with a less urgent alarm if a heart arrhythmia is detected. Using one or more detection algorithms, the cardiosaver can detect a change in the patient's electrogram that is indicative of a cardiac event within five minutes after it occurs and then automatically warn the patient that the event is occurring. To provide this warning, the guardian system includes an internal alarm sub-system (internal alarm means) within the cardiosaver and/or an external alarm system (external alarm means).

Abstract: A medical alarm communications system comprises a pager like device to be kept near a patient. The pager like device communicates medical alerts regarding the patient to a remote central station, which can provide therapeutic and/or diagnostic assistance by communicating to the pager like device. When the pager like device determines that an alert should be sent to the central station, it attempts to establish communication with the central station according to a primary communication protocol. If this attempt is unsuccessful according to some predetermined criteria (e.g. too much time has elapsed before communication is established), then the pager like device generates a message to the patient indicative of the failure, and The attempts to establish communication with the central station according to a secondary communication protocol.

Abstract: Disclosed is a system for the detection of cardiac events (a guardian system) that includes an implanted device called a cardiosaver, a physician's programmer and an external alarm system. The system is designed to provide early detection of cardiac events such as acute myocardial infarction or exercise induced myocardial ischemia caused by an increased heart rate or exertion. The system can also alert the patient with a less urgent alarm if a heart arrhythmia is detected. Using one or more detection algorithms, the cardiosaver can detect a change in the patient's electrogram that is indicative of a cardiac event within five minutes after it occurs and then automatically warn the patient that the event is occurring. To provide this warning, the guardian system includes an internal alarm sub-system (internal alarm means) within the cardiosaver and/or an external alarm system (external alarm means).