Sleep analysis: demonstrating
the continuum
Oxford UK, February 15th 2002 - A paper appearing
in EMBC(1) reports a major advance in the study of
sleep disorders. Oxford BioSignals, a spin-out company
from Oxford University, has developed and validated
BioSleep, a novel system based on neural network
analysis, which not only elucidates the microstructure
of sleep - fleeting changes which have never before
been consistently demonstrated - but also reliably
detects abnormal sleep patterns.
Electroencephalograms (EEG) have been used to diagnose
sleep disorders since the 1930s. However, conventional
monitoring analyses sleep in 30-second segments,
and so clinicians have been unable to study the events
occurring within each segment.
BioSleep, however, captures sleep on a second-by-second
basis. It is this which enables transient events
- micro-arousals lasting no more than 10 seconds,
and rapid shifts from one stage of sleep to another
- to become apparent. Here, for the first time, is
a tool which demonstrates sleep as comprising not
a succession of discrete stages but a night-long
progression forwards and backwards along the sleep/wake
continuum. 'What we may be seeing for the first time
is abnormal sleep in patients currently presenting
with problems but with no clear diagnosis,' says
Professor Thomas Roth, director of the Clara Ford
Clinic, Detroit, USA.
As many as one in ten people suffer with sleep disorders
- more than 90 are known - with well-recognised effects
on performance. Sleep disturbance is now associated
with an increase in road accidents, cardiovascular
disease and asthma, and is estimated to cost industry
$18bn each year in lost productivity. Diagnosis and
appropriate treatment depend on accurate analysis
of sleep data, but interpretation of a single night's
sleep may take up to five hours. In addition, well-documented
differences in interpretation between experts mean
that diagnosis is highly subjective.
Studies confirm that BioSleep's unique neural network
technology provides the consistency and accuracy
of interpretation which is lacking in conventional
systems. The ability to see sleep in a new way, and
to analyse it reliably and rapidly, represents a
significant advance in the management of sleep disorders.
'It is critically important to distinguish between
arousals in apnoea and arousal in insomniacs. This
exciting new technology may allow us to make this
distinction, and offer patients much-needed and appropriate
treatment,' says Professor Roth.
1. McGrogan N, Braithwaite E, Tarassenko L. BioSleep:
a comprehensive sleep analysis system. Proc 23rd
Annual International Conference of the IEEE Engineering
in Medicine and Biology Society, Istanbul 24-28 Oct
2001, no 1032 |
