European research center IMEC has developed a sleep staging system that can record EEG signals in the comfort of one’s home. The prototype device has already been successfully tested at the University Hospital Center (CHU) in Charleroi, André Vésale Hospital (Belgium).
The system consists of a head band with three sensor nodes measuring 2 EEG-channels (electroencephalogram) to monitor the brain activity, 2 EOG-channels (electro-oculogram) to monitor the eye activity and 1 EMG-channel (electromyogram) to monitor the chin muscle activity. These 5 signals provide the required information for sleep staging according to the Rechtschaffen and Kales standard. The sensor nodes integrate IMEC’s proprietary ultra-low power biopotential read-out ASIC (application-specific integrated circuit) to amplify and filter the 5 different ExG signals. The measured ExG signals are wirelessly transmitted to the recording computer. No additional wires from the head to the body or from the head to the recording device are needed, making the system comfortable to wear. The system is optimized for low power resulting in 12 hours autonomy.
The system has been validated in a controlled clinical environment and benchmarked with state-of-the-art ambulatory monitoring equipment. 12 healthy volunteers were enrolled in the study, and were monitored for a complete night using the wireless and the reference systems set-up in parallel. At the end of the study, the signals were given to a sleep expert for blind scoring, leading to two hypnograms for each subject. From the hypnograms, sleep statistics such as percentage of sleep time in each stage were deducted, and compared for the two systems. Hypnograms were also compared directly for similarity. The analysis proved the potential of wireless sleep staging systems to replace the current monitoring systems.
Press release: Wireless sensor systems enable a better sleep…