Physical activity assessment objective
Combined heart rate and motion sensor
16th November 2021
Soren Brage, University of Cambridge
Actiheart is a single-piece combined heart rate and uniaxial acceleration monitor that is worn on the chest using two standard ECG electrodes. It has three recording modes; 1) raw waveform mode, 2) inter-beat-interval logging mode, and 3) long-term recording mode of average heart rate and movement in epochs. Raw sampling rates are 128Hz for the ECG signal and 32 Hz for the acceleration signal. There are two official versions of the uniaxial monitor, the original Actiheart and Actiheart 4; these are largely identical in terms of weight (<10g) and physical dimensions. Actiheart 4 has four times higher memory capacity and can collect 15-sec epoch data for 11 days in long-term mode; its capacity is about 4 days when using inter-beat-interval logging (with 15-sec accelerometry data).