Abstract: Method and apparatus for detecting the occurrence of heartbeats in an ECG signal which may also include pacer artifacts, comprising analysis of the ECG signal for providing a heartbeat signal indicating detection of the occurrence of a heartbeat, analysis of the ECG signal for providing a pacer artifact signal indicating detection of the occurrence of a pacer artifact, analysis of the ECG signal in a manner independent from the first-mentioned analysis for determining if a portion of the ECG signal which follows detection of a pacer artifact has changes in its amplitude level which indicate the validity of the heartbeat indicating signal, and use of the result of the last-mentioned analysis to control the providing of the heartbeat indicating signal by the first-mentioned analysis.

Abstract: A method and apparatus for comparing waveshape portions of at least one time-varying signal by first forming initial templates of digital signal samples representative of the amplitude of successive time-spaced samples of portions of the time-varying signal. Next, forming reduced templates having a number of digital signal elements which is less than the number of samples in corresponding ones of the initial templates, each element of the reduced template comprising a combination of at least two samples from its corresponding initial template. And then processing corresponding elements of at least two of the reduced templates for deriving a signal representative of the degree of similarity of the respective portions of the time-varying signal represented by at least two reduced templates.

Abstract: A personal alarm system is disclosed which incorporates a speakerphone so as to permit substantially handsfree operation and remote activation. The system includes a speakerphone which interfaces to a subscriber station. The subscriber station in turn interfaces over a communications link to a central monitoring station which is operative to receive and analyze messages transmitted to the central monitoring station by the subscriber station. Following transmission of a message from the subscriber station to the central monitoring station, the central monitoring station may transmit a control signal to the subscriber station which causes the subscriber station to activate the speakerphone to permit verbal communication with a subscriber who may be immobilized and/or physically unable to initiate a telephone call or answer a telephone.

Abstract: An improved R-wave detector is provided for use in monitoring and/or analyzing electrical heart waveforms. Generally conventional R-wave detection means employ automatically variable scaling means for providing a threshold or reference value to a comparator which is variable not only in magnitude but also as a percentage of the average R-wave peak value from which it is derived. An ECG waveform is compared with this threshold of automatically variable percentage value and an indication of R-wave occurrence is provided when the ECG waveform exceeds the threshold. Upon an indication of R-wave occurrence, the percentage value of the threshold is rapidly increased such that a closely following T-wave of unusually large magnitude is not falsely detected as an R-wave.

Abstract: Apparatus for the recognition of ventricular premature beats by an identifying width of a QRS complex by dividing the area by the height and further noting when the width measurements is at least 40% wider than the average width of the immediately preceding several QRS complexes. Additional apparatus for indicating ventricular premature beats by determination of an early width determination which exceeds the average width by at least 20% and is additionally followed by the compensatory pause as determined by interbeat interval measurement.