Medisana activity and sleep trackers medisana 1094512 the vifit activity tracker will precisely monitor all daily and nightly physical activity as well as the duration and quality of sleep the monitor is small enough to be carried in a pocket or can be worn on the wrist using the supplied wristband in activity mode the device will track steps distance covered calories burned activity time and percentage of daily target the highly sensitive 3d motion sensor reacts to steps and not vibran