Low-cost daily pacemaker monitoring system.

To reduce the cost of pacemaker monitoring, we developed an inexpensive cardiac pacemaker interval monitor that detects electromagnetic radiation of the electrical pulse generated by an implanted pacemaker. The pulse interval is timed by logic systems and a piezoelectric crystal. Pulse interval is computed to the nearest 0.1 msec. The device is battery powered and can be used at home by the patient to monitor pulse interval daily with little cost after the initial expenditure. The unit may also be used by the physician to detect the stability or constancy of random variation of the pulse interval. From a daily record of measurements of the pulse interval, limits are set by the physician to predict impending battery exhaustion. Eight patients have been monitored for up to 24 months.