  In the paper a ballistocardiographic sensor for remote monitoring of activity
and vital parameters is presented. The sensor is mainly intended for use in
monitoring systems supporting care of older people. It allows to detect
occupancy of a piece of furniture, to which it is attached and to estimate
basic vital parameters (heart and respiration rates) of the monitored person.
The presented device includes three inertial sensors: two accelerometers of
different parameters and prices and one reference BCG module. The device sends
the measurement results to the external server over WiFi. The vital parameters
are estimated based on the Continuous Wavelet Transform of the registered
acceleration signals. User's presence is detected by tracking changes in
acceleration measured in axes parallel to the ground.
