Comparison of two motion sensors for use in cardiac telerehabilitation.

We compared the activity estimated by a pedometer and an accelerometer in coronary artery disease patients included in a phase III cardiac rehabilitation programme. Nine patients were divided into two groups and wore the pedometer for four weeks, and then subsequently the accelerometer for four weeks, or vice versa. The recorded daily exercise level (total daily steps and calories burned) was measured for each patient and compared with oxygen uptake and ventilatory threshold measured by ergospirometry at the end of the study. There was a significant correlation between the calories measured by the accelerometer and the ventilatory threshold (i.e. the sub-maximal capacity), r = 0.75 (P = 0.05). There was a significant correlation between the measured steps on the accelerometer and the ventilatory threshold, r = 0.72 (P = 0.07). There were no significant correlations for the pedometer. A questionnaire concerning ease of use of the sensors indicated that the cardiac patients favoured the pedometer.