Abstract: A system and method for obtaining an OIS coordinate frame comprising an electronic control unit configured to determine a local 3D electric field loop, create a zero mean version of E(t) over a depolarization interval, compute an ? value at each of a plurality of time intervals, compute an initial estimate of ? from a cross product of E and the ? value for each of the plurality of time intervals, average the initial estimate of ? from each of the plurality of time for a best estimate of ?, determine a plurality of â(?) values and using the corresponding {circumflex over (n)}(?) values, compute a composite match score, and choose at least one best value for â and a best value for {circumflex over (n)}.

Abstract: A system and method for non-invasively detecting abnormal electrical propagation in the heart are disclosed. The system and method include an interface for receiving a pacing signal applied to a heart of a patient, the pacing signal comprising (i) a sequence of regular pacing stimuli shorter than the sinus-rate intervals, and (ii) one or more extra pacing stimuli at intervals that are shorter than the regular pacing stimuli, a processor to assess the envelope of a body-surface ECG component after the regular pacing stimuli, assess the envelope of a body surface ECG component after the one or more extra pacing stimuli, and compare the assessed component after the extra pacing stimuli to the assessed component after the regular pacing stimuli. The interface outputting the comparison as an indication of regions of arrhythmogenicity and ablation targets in the heart.

Abstract: A system and method for obtaining an OIS coordinate frame comprising an electronic control unit configured to determine a local 3D electric field loop, create a zero mean version of E(t) over a depolarization interval, compute an ? value at each of a plurality of time intervals, compute an initial estimate of ? from a cross product of E and the ? value for each of the plurality of time intervals, average the initial estimate of ? from each of the plurality of time for a best estimate of ?, determine a plurality of â(?) values and using the corresponding {circumflex over (n)}(?) values, compute a composite match score, and choose at least one best value for â and a best value for {circumflex over (n)}.

Abstract: A system and method for obtaining an OIS coordinate frame comprising an electronic control unit configured to determine a local 3D electric field loop, create a zero mean version of E(t) over a depolarization interval, compute an ? value at each of a plurality of time intervals, compute an initial estimate of ? from a cross product of E and the ? value for each of the plurality of time intervals, average the initial estimate of ? from each of the plurality of time for a best estimate of ?, determine a plurality of â(?) values and using the corresponding {circumflex over (n)}(?) values, compute a composite match score, and choose at least one best value for â and a best value for {circumflex over (n)}.

Abstract: A system and method for obtaining an OIS coordinate frame comprising an electronic control unit configured to determine a local 3D electric field loop, create a zero mean version of E(t) over a depolarization interval, compute an ? value at each of a plurality of time intervals, compute an initial estimate of ? from a cross product of E and the ? value for each of the plurality of time intervals, average the initial estimate of ? from each of the plurality of time for a best estimate of ?, determine a plurality of â(?) values and using the corresponding {circumflex over (n)}(?) values, compute a composite match score, and choose at least one best value for â and a best value for {circumflex over (n)}.

Abstract: A system and method for obtaining an OIS coordinate frame comprising an electronic control unit configured to determine a local 3D electric field loop, create a zero mean version of E(t) over a depolarization interval, compute an ? value at each of a plurality of time intervals, compute an initial estimate of ? from a cross product of E and the ? value for each of the plurality of time intervals, average the initial estimate of ? from each of the plurality of time for a best estimate of ?, determine a plurality of â(?) values and using the corresponding {circumflex over (n)}(?) values, compute a composite match score, and choose at least one best value for â and a best value for {circumflex over (n)}.

Abstract: A system and method for obtaining an OIS coordinate frame comprising an electronic control unit configured to determine a local 3D electric field loop, create a zero mean version of E(t) over a depolarization interval, compute an ? value at each of a plurality of time intervals, compute an initial estimate of ? from a cross product of E and the ? value for each of the plurality of time intervals, average the initial estimate of ? from each of the plurality of time for a best estimate of ?, determine a plurality of â(?) values and using the corresponding {circumflex over (n)}(?) values, compute a composite match score, and choose at least one best value for â and a best value for {circumflex over (n)}.

Abstract: A system and method for monitoring cell voltages for a plurality of electrochemical cells connected in series forming a cell stack. The method includes dividing the cells into at least two cell groups, measuring the voltage across each cell group and estimating the minimum cell voltage for each group based on the average cell stack voltage and an estimated number of deficient cells in each group. The lowest minimum cell voltage for the entire cell stack is then determined.

Abstract: A method and apparatus are provided for measuring impedance and voltage characteristics of cells of multi-cell electrochemical devices, for example a battery or a fuel cell stack. Voltages are measured across individual cells, or groups of cells. At the same time, a load is connected in series with the electrochemical device. Both the device for measuring the voltages and the load are controlled together, preferably by means of a controller, which can include some form of microprocessor. This enables the load to be controlled to provide a desired combination of DC and AC current characteristics. By setting appropriate DC and AC current characteristics, desired characteristics of the impedance of individual cells can be measured.