Abstract: First cardiac signal data generated from measured heart beats of a subject is received. Characteristics of alternans occurring in the received first cardiac signal data are determined. Second cardiac signal data generated from measured heart beats of the subject after a change relating to an administration of a pharmacological agent is received. Characteristics of alternans occurring in the received second cardiac signal data are determined. The characteristics of alternans occurring in the received first cardiac signal data are compared with the characteristics of alternans occurring in the received second cardiac signal data.

Abstract: Cardiac signal data of heart beats measured with an ambulatory electrocardiography device is accessed. The cardiac signal data is segmented into cardiac signal data segments such that each cardiac signal data segment includes cardiac signal data of sequential heart beats. Whether alternans is present in the cardiac signal data segment is determined for each of multiple cardiac signal data segments. Characteristics of the alternans is determined by analyzing cardiac signal data segments for which alternans is determined to be present or by analyzing characteristics of cardiac signal data segments for which alternans is determined to be present.

Abstract: One or more electrocardiographic signals are detected from a subject. The occurrence of alternans in the electrocardiographic signals are detected using one or more processors. One or more characteristics of detected alternans are determined. The determined characteristics of the detected alternans are analyzed to determine whether cardiac ischemia is present.

Abstract: Method for determining physiological stress. One or more physiologic signals in a subject is detected. The one or more physiologic signals are processed to obtain one or more processed signals. The subject's stress level is estimated from the one or more processed signals. The one or more physiological signals may include the electrocardiogram, instantaneous lung volume or other signal reflecting respiratory activity, or the arterial blood pressure or other signal reflecting cardiovascular activity.

Abstract: Method and apparatus are introduced for determining proportional cardiac output (CO), absolute left atrial pressure (LAP), and/or other important hemodynamic variables from a contour of a circulatory pressure waveform or related signal. Certain embodiments of the invention provided herein include the mathematical analysis of a pulmonary artery pressure (PAP) waveform or a right ventricular pressure (RVP) waveform in order to determine beat-to-beat or time-averaged proportional CO, proportional pulmonary vascular resistance (PVR), and/or LAP. The invention permits continuous and automatic monitoring of critical hemodynamic variables with a level of invasiveness suitable for routine clinical application. The invention may be utilized, for example, to continuously monitor critically ill patients with pulmonary artery catheters installed and chronically monitor heart failure patients instrumented with implanted devices for measuring RVP.

Abstract: Method and apparatus are introduced for determining proportional cardiac output (CO), absolute left atrial pressure (LAP), and/or other important hemodynamic variables from a contour of a circulatory pressure waveform or related signal. Certain embodiments of the invention provided herein include the mathematical analysis of a pulmonary artery pressure (PAP) waveform or a right ventricular pressure (RVP) waveform in order to determine beat-to-beat or time-averaged proportional CO, proportional pulmonary vascular resistance (PVR), and/or LAP. The invention permits continuous and automatic monitoring of critical hemodynamic variables with a level of invasiveness suitable for routine clinical application. The invention may be utilized, for example, to continuously monitor critically ill patients with pulmonary artery catheters installed and chronically monitor heart failure patients instrumented with implanted devices for measuring RVP.

Abstract: A system and methodology are provided for using hierarchical groupings to organize governance, risk, and compliance (GRC) policies and rules. The groupings are based on categorizations that can be arbitrarily represented by both predetermined and user-defined hierarchical policy naming schemes. Once GRC regulatory and compliance policies and rules are grouped to accommodate company policies, testing can be designed around groups of policies and/or rules and scheduled to align with schedule and timing requirements. By allowing a policy or rule to be associated with multiple hierarchies, a single execution of a policy or rule can be associated with, managed from, and satisfy multiple regulatory and compliance needs with one effort.

Abstract: A method for identifying infants at risk for SIDS includes applying electrodes to an infant, receiving electrical signals from the electrodes, analyzing the received electrical signals to measure alternans of a heart of the infant, and identifying whether the infant is at risk for SIDS. A system for identifying infants at risk for SIDS includes an input unit configured to receive electrical signals from electrodes applied to an infant, a processor connected to the input unit and configured to process the received electrical signals to measure alternans of a heart of the infant, and a comparator configured to compare the measured alternans with alternans in a population of infants.

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 are introduced for determining proportional cardiac output (CO), absolute left atrial pressure (LAP), and/or other important hemodynamic variables from a contour of a circulatory pressure waveform or related signal. Certain embodiments of the invention provided herein include the mathematical analysis of a pulmonary artery pressure (PAP) waveform or a right ventricular pressure (RVP) waveform in order to determine beat-to-beat or time-averaged proportional CO, proportional pulmonary vascular resistance (PVR), and/or LAP. The invention permits continuous and automatic monitoring of critical hemodynamic variables with a level of invasiveness suitable for routine clinical application. The invention may be utilized, for example, to continuously monitor critically ill patients with pulmonary artery catheters installed and chronically monitor heart failure patients instrumented with implanted devices for measuring RVP.

Abstract: Identifying infants at risk for SIDS includes applying electrodes to an infant, receiving electrical signals from the electrodes, analyzing the received electrical signals to measure alternans of a heart of the infant, and identifying whether the infant is at risk for SIDS. A system for identifying infants at risk for SIDS includes an input unit configured to receive electrical signals from electrodes applied to an infant, a processor connected to the input unit and configured to process the received electrical signals to measure alternans of a heart of the infant, and a comparator configured to compare the measured alternans with alternans in a population of infants.

Abstract: The present invention provides methods and apparatus for determining a dynamical property of the systemic or pulmonary arterial tree using long time scale information, i.e., information obtained from measurements over time scales greater than a single cardiac cycle. In one aspect, the invention provides a method and apparatus for monitoring cardiac output (CO) from a single blood pressure signal measurement obtained at any site in the systemic or pulmonary arterial tree or from any related measurement including, for example, fingertip photoplethysmography.

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: A method for identifying infants at risk for SIDS includes applying electrodes to an infant, receiving electrical signals from the electrodes, analyzing the received electrical signals to measure alternans of a heart of the infant, and identifying whether the infant is at risk for SIDS.

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.

Abstract: Perfusion measurement method. The method includes detecting a signal emanating from the tissue and processing the signal to detect fluctuations substantially spatially correlated on a length scale less than 1 centimeter. The fluctuations are then analyzed to obtain a measure of perfusion. In one embodiment, the detected fluctuations are substantially correlated with fluctuations of a biological parameter such as the cardiac cycle or the respiratory cycle.

Abstract: A subject suspected of experiencing a myocardial infarction is monitored by applying sensors to the subject, where the sensors are configured to produce electrical signals representative of cardiac activity of the subject. Electrical signals are received from at least two of the sensors. The received signals then are processed to obtain a localized cardiac measure that is analyzed to determine whether the subject is experiencing a myocardial infarction.

Abstract: Cardiac electrical stability is assessed by generating a measure of cardiac electrical stability (e.g., an alternans measure) using a physiologic signal representative of activity of a patient's heart, generating a reference signal that provides information regarding whether the measure is representative of cardiac electrical stability, and visually presenting the measure and the reference signal in a way that permits visual evaluation of whether the measure is representative of cardiac electrical stability in view of characteristics of the reference signal.

Abstract: A localized cardiac measure, such as a localized measure of myocardial ischemia, is obtained by applying sensors to a subject, where the sensors are configured to produce electrical signals representative of cardiac activity of the subject. The subject's heart is then physiologically stressed by, for example, exercise stress testing, and electrical signals are received from at least two of the sensors. The received signals then are processed to obtain a localized cardiac measure.