Abstract: A system and a method are provided for using a mobile computing system comprising that has a communication connection configured to communicate with an electrocardiographic (ECG) apparatus to acquire ECG signals from the subject through a plurality of ECG leads. The system includes a processor configured to receive the ECG signals through the communications connection and process the ECG signals to estimate at least one of a respiratory rate of the subject, a tidal volume of the subject, or an ischemic index or repolarization alternans of the subject, from the ECG signals. The processor is further configured to generate an alert upon determining at least one of the ischemic index or repolarization alternans is above a threshold value or a change in respiratory rate or tidal volume indicative of an abnormal respiratory event. The system also includes a display configured to display the alert.

Abstract: A system and a method are provided for using a mobile computing system comprising that has a communication connection configured to communicate with an electrocardiographic (ECG) apparatus to acquire ECG signals from the subject through a plurality of ECG leads. The system includes a processor configured to receive the ECG signals through the communications connection and process the ECG signals to estimate at least one of a respiratory rate of the subject, a tidal volume of the subject, or an ischemic index or repolarization alternans of the subject, from the ECG signals. The processor is further configured to generate an alert upon determining at least one of the ischemic index or repolarization alternans is above a threshold value or a change in respiratory rate or tidal volume indicative of an abnormal respiratory event. The system also includes a display configured to display the alert.

Abstract: A system and method for determining and controlling a cardiac condition of a subject are provided. In some aspects, the method includes acquiring ECG signals using one or more electrodes configured to sense a cardiac activity of a subject, and analyzing the ECG signals to delineate cardiac waveforms on a beat-to-beat basis. The method also includes identifying, in the delineated cardiac waveforms, characteristic points associated with different phases of cardiac activity, and for each delineated cardiac waveform, computing an ischemic index using the ECG signals corresponding to a ventricular depolarization period and a ventricular repolarization period, wherein the ventricular depolarization period and the ventricular repolarization period are defined by the identified characteristic points. The method further includes determining a cardiac condition of the subject using each computed ischemic index.

Abstract: A method and apparatus are disclosed for preventing heart rhythm disturbances by optimally recording cardiac electrical activity, optimally measuring beat-to-beat variability in the morphology of electrocardiographic waveforms, and using the measured beat-to-beat variability to control the delivery of therapy to the heart.

Abstract: A system and a method are provided for deriving elctrocardiographic (ECG] signals from a subject. The system includes an ECG apparatus configured to acquire ECG signals from the subject through a plurality of ECG leads, wherein the plurality of ECG leads includes lead groups that are traditionally presumed to be orthogonal. A processor or method are provided to analyze combinations of ECG leads from the plurality of ECG leads to determine a spectral signal-to-noise ratio (SNR] for each combination of ECG leads and select a combination of ECG leads that provides a desirable spectral SNR. The ECG signals derived from the combination of ECG leads selected as providing the desirable spectral SNR may be provided or may be used to derive and report respiratory rate information about the subject.

Abstract: A system and method for determining and controlling a cardiac condition of a subject are provided. In some aspects, the method includes acquiring ECG signals using one or more electrodes configured to sense a cardiac activity of a subject, and analyzing the ECG signals to delineate cardiac waveforms on a beat-to-beat basis. The method also includes identifying, in the delineated cardiac waveforms, characteristic points associated with different phases of cardiac activity, and for each delineated cardiac waveform, computing an ischemic index using the ECG signals corresponding to a ventricular depolarization period and a ventricular repolarization period, wherein the ventricular depolarization period and the ventricular repolarization period are defined by the identified characteristic points. The method further includes determining a cardiac condition of the subject using each computed ischemic index.

Abstract: Method and apparatus for preventing heart rhythm disturbances by recording cardiac electrical activity, measuring beat-to-beat variability in the morphology of electrocardiographic waveforms, and using the measured beat-to-beat variability to control the delivery of electrical impulses to the heart during the absolute refractory period.

Abstract: Method and apparatus for preventing heart rhythm disturbances by recording cardiac electrical activity, measuring beat-to-beat variability in the morphology of electrocardiographic waveforms, and using the measured beat-to-beat variability to control the delivery of electrical impulses to the heart during the absolute refractory period.

Abstract: A method and apparatus are disclosed for preventing heart rhythm disturbances by optimally recording cardiac electrical activity, optimally measuring beat-to-beat variability in the morphology of electrocardiographic waveforms, and using the measured beat-to-beat variability to control the delivery of therapy to the heart.

Abstract: A method for identifying a susceptibility of a subject to atrial-rhythm disturbances includes a) placing a plurality of sensors on the subject to measure a physiologic signal of the subject, and b) recording the physiologic signal from the sensor. The physiologic signal includes an atrial electrical activity of the subject. The method includes c) determining a beat-to-beat variability in the atrial electrical activity of the subject. The beat-to-beat variability includes alternans of electrocardiographic waveforms of a predetermined number of a sequence of heart beats. The method includes d) determining a susceptibility to atrial-rhythm disturbances of the subject using the beat-to-beat variability in the atrial electrical activity determined in step c), and e) generating a report of the susceptibility to atrial-rhythm disturbances of the subject.

Abstract: Method and apparatus for preventing heart rhythm disturbances by recording cardiac electrical activity, measuring beat-to-beat variability in the morphology of electrocardiographic waveforms, and using the measured beat-to-beat variability to control the delivery of electrical impulses to the heart during the absolute refractory period.

Abstract: A method for identifying a susceptibility of a subject to atrial-rhythm disturbances includes a) placing a plurality of sensors on the subject to measure a physiologic signal of the subject, and b) recording the physiologic signal from the sensor. The physiologic signal includes an atrial electrical activity of the subject. The method includes c) determining a beat-to-beat variability in the atrial electrical activity of the subject. The beat-to-beat variability includes alternans of electrocardiographic waveforms of a predetermined number of a sequence of heart beats. The method includes d) determining a susceptibility to atrial-rhythm disturbances of the subject using the beat-to-beat variability in the atrial electrical activity determined in step c), and e) generating a report of the susceptibility to atrial-rhythm disturbances of the subject.

Abstract: Method and apparatus for preventing autonomic system disturbances by recording physiological parameters, measuring beat-to-beat variability of these parameters, and using the measured beat-to-beat variability to control the delivery of drug therapy and electrical impulses to the heart.

Abstract: Method and apparatus for preventing heart rhythm disturbances by recording cardiac electrical activity, measuring beat-to-beat variability in the morphology of electrocardiographic waveforms, and using the measured beat-to-beat variability to control the delivery of drug therapy and electrical impulses to the heart.

Abstract: Method and apparatus for preventing heart rhythm disturbances by recording cardiac electrical activity, measuring beat-to-beat variability in the morphology of electrocardiographic waveforms, and using the measured beat-to-beat variability to control the delivery of electrical impulses to the heart during the absolute refractory period.

Abstract: Method and apparatus for preventing heart rhythm disturbances by recording cardiac electrical activity, measuring beat-to-beat variability in the morphology of electrocardiographic waveforms, and using the measured beat-to-beat variability to control the delivery of drug therapy and electrical impulses to the heart.

Abstract: This invention involves method and apparatus for guiding ablative therapy of abnormal biological electrical excitation. In particular, it is designed for treatment of cardiac arrhythmias. In the method of this invention electrical signals are acquired from passive electrodes, and an inverse dipole method is used to identify the site of origin of an arrhythmia. The location of the tip of the ablation catheter is similarly localized from signals acquired from the passive electrodes while electrical energy is delivered to the tip of the catheter. The catheter tip is then guided to the site of origin of the arrhythmia, and ablative radio frequency energy is delivered to its tip to ablate the site.

Abstract: This invention involves method and apparatus for guiding ablative therapy of abnormal biological electrical excitation. In particular, it is designed for treatment of cardiac arrhythmias. In the method of this invention electrical signals are acquired from passive electrodes, and an inverse dipole method is used to identify the site of origin of an arrhytmia. The location of the tip of the ablation catheter is similarly localized from signals acquired from the passive electrodes while electrical energy is delivered to the tip of the catheter. The catheter tip is then guided to the site of origin of the arrhythmia, and ablative radio frequency energy is delivered to its tip to ablate the site.