Today, at IEEE EMB Conference in Minneapolis, Minnesota (USA), IMEC,
a world-leading independent research center in nanoelectronics and nanotechnology,
and its research affiliate Holst Centre present 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.
Caption: Wireless sleep monitoring for enhanced patient comfort.
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. Home monitoring does not only increase the comfort
of the patient, it is also a cost-efficient solution for expensive and time-consuming
monitoring in hospitals. Moreover, wireless monitoring systems provide more
natural daily life monitoring results. Industry can get access to the technology
by joining the Human++ program as research partner or by licensing agreements
for further product development.
Posted September 2ndt, 2009