Cardiac ambulatory monitor

Claim 1

An ambulatory arrhythmia detection and ECG recorder adapted to be carried by a patient comprising: (A) a plurality of electrodes adapted to be placed on the patient's body for developing electrical signals indicative of the patient's cardiac rhythm; (B) amplifier and filter means connected to said electrodes for amplifying and filtering said electrical signals; (C) recording means for recording the amplified and filtered electrical signals; (D) recorder controller means having a plurality of inputs, said controller means activating said recording means whenever a control signal is applied to one of its inputs; (E) timing means connected to said controller means and said recording means for deactivating said recording means after a preset time period has elapsed; (F) means for converting said amplified and filtered electrical signals into a pulse train wherein each pulse represents a different QRS complex in said electrical signals and is generated in real time with its respective QRS complex; (G) means for determining a tachycardia condition and being connected to one of said inputs to provide a first control signal thereto whenever a tachycardia condition is sensed; (H) said means for determining a tachycardia condition including: (i) a first oscillator controlled counter which counts at a first predetermined rate to a first predetermined number and which generates a first output signal each time it reaches said predetermined number; (ii) said first counter having a reset input and having said pulse train applied thereto so that said counter is reset upon the receipt of each pulse; (iii) a first accumulator having a reset input and a clock input, said reset input receiving said first output signals from said first counter to reset the accumulator each time a first output signal is received, said clock input receiving said pulse train to increment said accumulator each time a pulse is received, said accumulator producing said first conrol signal whenever the same is incremented to a first preset number; (I) means for determining a bradycardia condition and being connected to another of said inputs to provide a second control signal thereto whenever a bradycardia condition is sensed, said means for determining a bradycardia condition including: (i) a second oscillator controlled counter which counts at a second predetermined rate to a second predetermined number and which generates a second output signal each time it reaches said predetermined number; (ii) said second counter having a reset input and having said pulse train applied thereto so that said counter it reset upon receipt of each pulse; (iii) a second accumulator having a clock input receiving said second output signals to increment said second accumulator each time a second output signal is received, said second accumulator producing said second control signal whenever the same is incremented to the second preset number.