Using the power of thought to
control a robot that helps to move a paralysed hand: a project from the ETH
Rehabilitation Engineering Laboratory could fundamentally change the therapy
and daily lives of stroke patients. One in six people will suffer a stroke in
their lifetime. In Switzerland alone, stroke affects 16,000 people every year.
Two thirds of those affected suffer from paralysis of the arm. Intensive
training can – depending on the extent of damage to the brain – help patients
regain a certain degree of control over their arms and hands. This may take the
form of classic physio- and occupational therapy, or it may also involve
robots. Researchers developed a number of robotic devices that train hand
functions and sees this as a good way to support patient therapy. However, both
physio- and robot-assisted therapy are usually limited to one or two training
sessions a day; and for patients, traveling to and from therapy can also be
time consuming.
Another question that is still
not fully understood is how the brain controls limbs that interact with the
environment. For example, the robotics experts have developed an exoskeleton
that makes it possible to block the knee for 200 milliseconds while walking and
extend it by 5 degrees. With the help of sensors, the scientists measure the
forces that are involved and use this data to infer how the brain modulates the
stiffness of the knee. These findings then flow into applications such as the
control of new, active prostheses. If the researchers succeed in establishing
an interaction between the brain and the exoskeleton, the result will be a
device that is ideally suited for therapy. If, on the other hand, the deficits
are permanent, a robotic device could offer long-term support – as an
alternative to invasive methods, which are also being researched. These for
instance envisage implanting electrodes in the brain and triggering stimulators
in the muscles.
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