Comparison of activity sensors and algorithms for rate-responsive pacemakers using ambulatory monitoring

Various methods have been used to control rate-responsive pacemaker rates using activity as controlling signal. The purpose of this study was to compare the performance of two activity sensors (case-mounted piezoelectric and accelerometer), two bandpass filters (1-4 Hz and 15 Hz), and two signal processing algorithms (threshold counting and integration). Data were collected in 26 normal human subjects during protocols using treadmill, bicycle, and daily activity including driving a car. Performance was judged using the normal sinus rate as a standard. The accelerometer performed better than the case-mounted piezoelectric sensor (p<0.01). The threshold algorithm performed better than the signal integration algorithm using the accelerometer (p<0.05)