Ectopic heartbeat detector

Claim 1

A critical ectopic beat detector for providing a warning that an ectopic beat is approaching a critical portion of a heartbeat comprising first circuit means for monitoring a heartbeat including means for detecting a predetermined normal portion of a heartbeat and for detecting an ectopic beat, second circuit means for measuring the time relationship between said normal portion of said heartbeat and said ectopic beat, and third circuit means for providing an indication of when said ectopic beat bears a predetermined timed relationship to said normal portion of said heartbeat, said third circuit means including means for providing an alarm signal when said predetermined timed relationship is experienced, said heartbeat including a R-wave and wherein said first circuit means comprises first means for providing a first impulse each time that it is triggered by a R-wave and a second impulse when triggered by said ectopic beat, second means triggered by said first means to provide a reset pulse every time said first means is triggered by said R-wave, a free-running sawtooth generator coupled to said second means and triggered by said reset pulses to periodically reset said sawtooth generator whereby the magnitude of said sawtooth voltage at any particular time is a measure of elapsed time from each reset pulse and therefore from said R-wave, comparator means coupled to said sawtooth generator, potentiometer means coupled to said comparator to provide a voltage which is a measure of minimum desired elapsed time between said R-wave and a subsequent ectopic beat, said comparator comparing said sawtooth voltage with the output of said potentiometer means at the time of said ectopic beat to provide a first type of output when said potentiometer voltage is in excess of said sawtooth voltage and a second type of output when said potentiometer voltage is less than said sawtooth voltage, fourth circuit means coupling said comparator to said third circuit means for providing said third signal whenever said first type of output is obtained signifying that the elapsed time between said R-wave and said subsequent ectopic beat is less than said predetermined minimum, said first means comprising a first multivibrator for providing a first square wave of relatively long duration and said second means comprising a second multivibrator providing a second square wave of relatively short duration at a first predetermined portion of each of said first square waves, means for preventing said second square waves produced at the time of said ectopic beat from resetting said sawtooth generator, third means comprising a third multivibrator for providing a third square wave of relatively short duration at a second predetermined portion of said first square wave for acting as a sample pulse, a second comparator coupled to said sawtooth generator, second potentiometer means coupled to said second comparator for providing a voltage which is proportional to the time between adjacent R-waves, and said third circUit means including a logic circuit coupled to said third multivibrator and periodically energized by said sample pulses.