PR09(04)
2nd January 2004
Physicists use fractals to help Parkinson's
sufferers
A new
portable system for analyzing the walking patterns of people
with Parkinson's disease has been developed by researchers in
the US and Japan. The system, described in the Institute of
Physics publication Journal
of Neural Engineering, will help doctors monitor the
progress of the disease in patients and so tailor their
therapy and drug regime more accurately than previously
possible.
Parkinson's disease is a progressive disorder of the
central nervous system. Its symptoms include: uncontrollable
trembling, difficulty walking, and postural problems that
often lead to falls. These symptoms are usually controlled
with dopamine agonist drugs. However, these can have a number
of side-effects, such as jerking movements. It is also known
that the body builds up a tolerance to the drug.
Understanding the nature and severity of symptoms for
individual patients, which is reflected in their walking
pattern, could help doctors improve a patient's quality of
life, by guiding their treatment more effectively, and so
reduce side-effects.
Researchers have previously tried to quantify the
problems suffered by Parkinson's patients by studying their
gait. Now, Masaki Sekine, Metin Akay, and Toshiyo Tamura, of
the Department of Gerontechnology, National Institute for
Longevity Sciences, in Aichi, Japan and Thayer School of
Engineering, New Hampshire USA, working with their colleagues
at the Fujimoto Hayasuzu Hospital, in Miy azaki, Japan, have
devised a portable system based on a sensor placed on the
patient's body that measures movements in three dimensions.
The readings from this sensor, known as a tri-axial
accelerometer, are fed to a computer, together with
measurements of the patients walking speed, and analysed using
a fractal system.
Fractals
are usually associated with irregular geometric objects that
look the same no matter what scale they are viewed at: clouds,
branching trees, rugged coastlines, rocky mountains, are all
examples of fractals. The idea of a fractal can also be
applied to irregular motion. For instance, a healthy heartbeat
is now known not be so regular as we might think and follows a
fractal pattern of movement instead. Scientists have suggested
that fractals might also be used to model the irregular
walking pattern of people with Parkinson's disease.
The
researchers used the fractal analysis to break down the body
motion of healthy elderly subjects and patients with
Parkinson's disease into simpler component parts. The aim
being to reveal the differences in irregularity and complexity
of the way individuals in each group walk. The computer
analysis of the data revealed the complexity, as determined by
a fractal measure, of the walking patterns of each group. The
fractal measure falls between 1 and 2, and the higher the
fractal measure (close to 2) the more complex the body motion,
or the lower the fractal measure (close to 1) the less complex
the body motion.
The
authors say that the fractal measure for Parkinson's disease
patients is about 1.48, or higher than that of healthy elderly
subjects, whereas the healthy elderly subjects have a fractal
measure nearer 1.3.
This
confirms the fractal nature of the gait in Parkinson's
patients, says the team, and provides them with a quantitative
means to measure the severity of walking symptoms.
The
Journal of Neural Engineering was launched by the
Institute of Physics this week and can be viewed online at: http://jne.iop.org/.
Ends
Notes for editors
1. For
further information contact:
David Reid,
Press
Officer,
Insitute of Physics,
Tel: 020 7470 4815,
Mobile: 07734 256729,
E-mail: david.reid@iop.org.
2.
Alternatively, contact
Professor Metin Akay,
Thayer
School of Engineering,
Dartmouth College,
Hanover
NH 03755,
USA,
Tel: +1 603 646 0204,
Fax: +1
603 646 0770,
E-mail: metin.akay@dartmouth.edu.
3. The
paper, 'Fractal dynamics of body motion in patients with
Parkinson's disease' by Masaki Sekine, Metin Akay,
Toshiyo Tamura, Yuji Higashi, and Toshiro Fujimoto was
published in the Journal of Neural Engineering: Volume 1,
Number 1, March 2004.
4. The
Journal of Neural Engineering was launched this week and can
be viewed online at http://jne.iop.org/. The
solution to many neuroscience problems will involve highly
coordinated and highly interdisciplinary research efforts
between neurobiologists and engineers. This understanding is
crucial not only in allowing us to discover how large numbers
of cells can store and process information but also to
understand the mechanisms underlying neurological disorders
such as stroke, Parkinson's disease, Alzheimer's disease or
epilepsy. The launch of Journal of Neural Engineering reflects
the need for an accessible dialogue between these disciplines.
JNE aims to fulfil this need by providing a forum in which
neuroscientists, neurobiologists and engineers can publish
their work in one periodical. The journal will encompass all
aspects of this emerging field.
5. The
Institute of Physics is a leading international professional
body and learned society with over 37,000 members, which
promotes the advancement and dissemination of a knowledge of
and education in the science of physics, pure and applied. It
has a world-wide membership and is a major international
player in: ·
- scientific publishing and electronic dissemination of
physics;
- setting
professional standards for physicists and awarding
professional qualifications;
- promoting physics through scientific conferences,
education and science policy advice.
The
Institute is a member of the Science Council, and a nominated
body of the Engineering Council. The Institute works in
collaboration with national physical societies and plays an
important role in transnational societies such as the European
Physical Society and represents British and Irish physicists
in international organisations. In Great Britain and Ireland
the Institute is active in providing support for physicists in
all professions and careers, encouraging physics research and
its applications, providing support for physics in schools,
colleges and universities, influencing government and
informing public debate.
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