This week, at IEEE EMB Conference in Minneapolis,
Minnesota (USA), IMEC and its research
affiliate Holst Centre presented the clinical validation of a wireless sleep
staging system.
The miniaturized wireless system allows patients to wear the
device in the comfort of their home, thus enabling early screening of abnormal
sleep profiles outside clinics. The sleep staging system has been validated in
the sleep laboratory at the University Hospital Center (CHU) in Charleroi, André Vésale Hospital
(Belgium),
against a commercially available reference system. With this validation, the
technology is ready for product development at industry opening new perspectives
for remote and comfortable sleep monitoring.
Sleep disorder is a major health problem. 10% of the
population of the U.S.
is affected by sleep apneas, and 1 billion people worldwide experience some
kind of chronic nasal congestion during sleep. IMEC’s wireless sleep staging
system which is light weight, wearable and miniaturized can drastically
increase the comfort of sleep disorders tests. 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.
Within the Human++ program, IMEC and Holst Centre aim to
develop solutions for an efficient and better healthcare. Wireless sensor nodes
in intelligent body area networks may provide more comfortable healthcare
systems by enabling home monitoring of patients.
SOURCE: IMEC
