Abstract: In one embodiment, an electrical activity measurement system includes a catheter to be inserted into a body part and including at least one electrode, signal processing circuitry coupled to receive an intracardiac electrogram (IEGM) signal from the at least one electrode and process the IEGM signal for output to a recording apparatus via a cable, which picks up surrounding electrical noise, and feedback circuitry configured to receive at least some of the electrical noise picked up by the cable, and provide a feedback signal indicative of the received electrical noise to the signal processing circuitry, which is configured to compensate at least partially for the electrical noise, which is not yet in the IEGM signal but will be added to the IEGM signal in the cable, responsively to the feedback signal to produce a noise-compensated IEGM signal for output to the recording apparatus via the cable.

Abstract: Fast recovery electrocardiogram (ECG) signal method and apparatus are provided. In one embodiment, an ECG apparatus includes an input for receiving a biometric cardiogram signal, such as a Wilson Central Terminal (WCT) signal, and a combiner, such as an adder, for producing a compensated signal. An analog to digital converter provides a digitized version of the compensated signal to a processor. The processor produces an ECG reflective of the compensated signal and also outputs a digital signal corresponding to high frequency response of the digitized compensated signal to a digital to analog converter. The digital to analog converter provides an analog version of the digital signal corresponding to high frequency response of the digitized compensated signal to compensate for low response of the biometric cardiogram signal to high frequency spikes. A resultant ECG is produced by the processor having pacing signal contribution within the biometric cardiogram signal cancelled.

Abstract: A method includes receiving an anatomical mapping that includes multiple measurements acquired at multiple respective locations within an organ of a patient. An estimated surface of the organ is computed based on the measurements. A three-dimensional (3D) shell of the organ, which extends inwards from the estimated surface of the organ and has a predefined thickness, is defined. A quality of the anatomical mapping is estimated based on the measurements whose locations fall within the 3D shell.

Abstract: A method for acquiring electrical signals from a living subject, including injecting, via an injection electrode attached to the subject, a known calibration signal to the subject and measuring respective levels of output signals generated at input electrodes attached to the subject in response to the calibration signal. The method further includes deriving respective weighting factors for the input electrodes in response to the respective levels, and applying the respective weighting factors to physiological signals acquired by the input electrodes, so as to generate respective corrected physiological signals.