Abstract: A method of reducing noise in a biological signal, such as an ECG signal, includes acquiring a biological signal, comparing the biological signal to a representative signal, and generating a predicted signal corresponding to the representative signal when the biological signal sufficiently matches the representative signal. The predicted signal is subtracted from the biological signal to produce a second signal, and a filter is applied to the second signal to produce a filtered signal. The predicted signal and the filtered signal then are combined to produce a noise-reduced signal.

Abstract: The alternans pattern of cycle-to-cycle variability in physiologic waveforms is assessed by applying transducers to a subject, recording physiologic signals, and analyzing the alternans pattern of variation in waveform morphology.

Abstract: Method and apparatus for improved electronic display and interpretation of physiologic waveforms. The apparatus generates a two-dimensional grid on the video screen simulating the appearance of electrocardiographic recording paper or other physiologic signal recording paper. At least one physiologic signal is superimposed upon the grid for a display of the combined signal and grid. In a preferred embodiment of the invention the grid includes lines some of which are separated by no more than 2.6 millimeters. In another embodiment of the invention the grid includes horizontal or vertical lines of at least two types.

Abstract: The temporal pattern of cycle-to-cycle variability in physiologic waveforms, such as alternans, is assessed by applying transducers to a subject, recording physiologic signals, and analyzing the cycle-to-cycle variation in waveform morphology. Preferred embodiments include the application of physiologic stress to the subject in order to adjust heart rate to the desired range, real-time analysis of waveform variability, reduction in the effect of intercycle variability on waveform variability, improved techniques for determining the statistical significance of the amplitude of a temporal pattern of variability, handling of abnormal beats such as atrial and ventricular premature beats, and assessment of the statistical significance of a measured level of a temporal pattern of variability.

Abstract: A method and apparatus for determining mean blood pressure involves the use of a pre-programmed microprocessor which interprets pressure oscillation values from a pressure cuff affixed to a subject's limb. The pressure cuff is inflated to a value above apparent systolic pressure and then deflated in steps. The steps are all substantially equal mmHg declinations in cuff pressure. At each step cuff ocsillation values are taken and stored. The greatest cuff oscillation and its associated cuff pressure are noted, along with the next greatest cuff oscillations and associated cuff pressures on either side of the greatest oscillation. The actual mean blood pressure is then determined by forming a window adjacent to the greatest oscillation and calculating, on which side of the greatest oscilation, within the window, the mean pressure is disposed.

Abstract: A method and apparatus for determining mean blood pressure involves the use of a pre-programmed microprocessor which interprets pressure oscillation values from a pressure cuff affixed to a subject's limb. The pressure cuff is inflated to a value above apparent systolic pressure and then deflated in steps. The steps are all substantially equal mmHg declinations in cuff pressure. At each step cuff oscillation values are taken and stored. The greatest cuff oscillation and its associated cuff pressure are noted, along with the next greatest cuff oscillations and associated cuff pressures on either side of the greatest oscillation. The actual means blood pressure is then determined by forming a window adjacent to the greatest oscillation and calculating, on which side of the greatest oscillation, within the window, the means pressure is disposed.