A novel wearable sensor device for continuous monitoring of cardiac activity during sleep

The miniaturization and energy optimization of sensors opens up new possibilities in the field of sleep research. Wearable sensors are capable of recording vital parameters during sleep in a simple and unobtrusive manner. In order to analyze sleep architecture and sleep disorders, continuous monitoring of movements and cardiorespiratory parameters in high resolution is of central importance. In this paper a novel wearable sensor device based on impedance plethysmography (IPG) is presented, which is able to continuously monitor movements and cardiac parameters at the wrist. The sensor is designed to realize high resolution measurements up to 48 hours constantly. Measurements during sleep show that up to 98% of the pulse intervals are correctly detected. Furthermore, the comparison of the heart rate variability (HRV) parameters between IPG and the gold standard ECG demonstrate the potential of the sensor as a valid tool for ambulant sleep analysis.