Del Mar Avionics, Inc.

George J Kelen

Raphael Henkin

A method and apparatus for dynamically estimating the ST segment of a rate varying electrocardiogram by comparing the result yielded from a mathematical relationship between calculated beat averages and a predetermined standard. Typically a table of known heartbeats is made from which means for estimating are created. An average of beat to beat intervals is compared with the means for estimating and the length of the ST segment for any particular beat is derived making it possible to dynamically alter ST segment length for any given heartrate.

Dynamic ST segment estimation and adjustment

A frequency domain signal processing and analysis method and apparatus displays, plots and makes measurements upon electrocardiographic signals (ECG) recorded from the body surface. Both the graphic plots and the numeric parameters measured reveal abnormalities of electrical conduction within the heart thought to be important in the identification of patients at risk of serious disturbances of heart rhythm including sudden death. The invention employs Fourier analysis of short overlapping segments of ECG signal to create a three dimensional map ('spectrocardiogram') whose axes are time, fequency and power thus disclosing changes in the frequency content of the ECG signal over short intervals of time. In additoin to the Fourier analysis itself, the method and apparatus provides a wide choice of user-selectable signal pre-processing, post-processing, display and plotting options as well as performing custom mathematical computations upon the Fourier spectra to distinguish and quantify visually apparent differences between normal and abnormal spectrocardiograms.

Method and apparatus for spectral analysis of electrocardiographic

Frequency domain ECG signal processing systems and methods plot spectral maps and compute statistical parameters from surface electrocardiographic signals, which plots and parameters reveal abnormalities of electrical conduction within the hearts of patients at risk of ventricular tachycardia. Fourier analysis of short overlapping time segments of QRS ECG signal are used to create three dimensional spectral maps disclosing changes in the frequency spectral content of the ECG signal over the whole QRS region. Correlations and statistical evaluations of the spectral content between QRS time segment pairs quantify the spectral turbulence of the ECG and distinguish those at risk from ventricular tachyarrhythmias.

Surface ECG frequency analysis system and method based upon spectral

A system for detection, measurement, analysis and plotting of electrocardiographic signals with amplitudes ranging down to one microvolt (micropotentials) employing long term ambulatory (Holter) recordings. Multi-channel electrocardiograms are recorded on a Holter recorder that inscribes calibration pulses at the beginning of each tape. The tape is played back at high speed on a scanner which uses the recorded calibration pulses to automatically calibrate the signal gains for each signal channel. The played back signals are digitized at sufficient resolution and sampling rate to permit analysis of micropotentials. The digitized raw data is stored in a permanent computer file available for multiple further analyses. A template heart beat is designated and the raw data file is signal averaged to reduce random noise. The averaged beat thus produced is permanently stored, and analyzed using a variety of operator selected standard signal processing techniques to reveal and evaluate micropotential signals of clinical significance.

Micropotential analyzer--a Holter system with comprehensive analysis

A system for ambulatory monitoring and subsequent analysis and evaluation of pacemaker performance includes a recorder module which detects pacemaker spikes and in response to each spike generates a signal having a waveform compatible with commericially-available ambulatory ECG recorders, to permit ECG signals to be recorded in one channel of the recorder while simultaneously the pacemaker spike signals are recorded in another channel. The magnetic tape on which the signals are recorded is played back at 120 times the recording speed, typically, on a commercially-available playback analyzer which presents the pacemaker and ECG signals as separate outputs. The system further includes an analysis module connected to the playback unit and receiving from it the ECG signals and the pacemaker spike signals. The analysis module has counters which accumulate the number of paced beats and of fusion beats. The analysis module also includes circuits for sensing manifestations of pacemaker malfunction. When malfunction is sensed, the analysis module reduces the playback speed to facilitate study by an operator and activates a visual alarm. The conditions sensed include: failure-to-sense, failure-to-capture, and abnormal bradycardia.

Pacemaker monitoring recorder and malfunction analyzer

A recorder for monitoring the operation of a cardiac pacemaker and the response of the patient to the pacemaker includes a recorder module which receives a composite signal including an ECG signal, a pacemaker spike having a frequency spectrum that lies substantially at frequencies greater than the frequency band required to pass the ECG signal, and further includes artifact noise within the frequency spectrum of the pacemaker spike. The recorder module distinguishes the pacemaker spike from the artifact noise and upon recognizing the pacemaker spike, the recorder module produces a distinctive synthesized signal whose frequency spectrum lies substantially within the frequency band required to pass the ECG signal so that the synthesized signal will pass through the pre-emphasis filter that is used to reject artifact noise and will then be recorded.

Growing community of inventors

Staten Island, NY, United States of America

George J Kelen