Using only brain waves, patients can learn to manipulate a hand orthosis
quickly, according to a recent study. Test patients were able to harness their
brain waves based on the information they received from biofeedback.
This brain-computer-interface (BCI) control is powered by imaginary
movement of the hand, or a mental task, which is specific to each person and
allows the patient to manipulate the orthotic hand as necessary.
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| Ming-Shaung Ju |
Ming-Shaung Ju, PhD, professor in the mechanical engineering department
at the National Cheng Kung University in Tainan, Taiwan, and his colleagues
designed a BCI-based orthotic hand that would process patients’ mu waves
while imagining themselves performing a task, researchers said in the study.
Study authors took the task a step further, however, and developed a
control algorithm to supply the orthotic hand with the proper amount of force
necessary for each given task — grasping and holding an object, and
opening the hand — without additional patient effort. They also used this
algorithm to reduce the generation of wrong command, Ju told O&P
Business News.
Ju and his team used an electroencephalography (EEG) recorder and a
specialized amplifier to collect the patients’ brain waves.
They found that patients using orthoses were able to control them with
their minds, instead of using electromyography of the affected muscles or
action from the sound limbs like other interfaces currently available, he said.
The EEG-controlled orthosis served to both assist patients in grasping and
holding an object, and to retrain patients’ brains to comprehend such
commands.
Stroke patients, in particular, benefitted from this ability. Since they
needed to focus the control signals from the area of the brain that manages
hand movements, patients suffering from the effects of stroke essentially were
able to use the orthosis to “enhance the reorganization of their
brains,” Ju said.
Advances in motor technology, sensors and materials have made it
possible for more powerful and light-weight orthoses and prostheses to be
available now, he said. The next step, however, is to design an interface that
is as close to the human body as possible.
“From our experience, the human brain can adapt to the assistive
devices faster and [more] efficiently than one can imagine,” he said.
Ju said they have begun working with neurological professionals to begin
clinical patient testing, as well as to improve the technology of the hand
orthoses design and its functions.
“The human can be trained to control their brain waves, which
provide a good source for controlling orthoses or prostheses,” he said.
“With the help of biomedical engineering, these devices may have
therapeutic functions and beneficial for neurological patients.” —
by Stephanie Z. Pavlou
To my knowledge, the development of brain-computer interface (BCI) has
been a topic of interest, for many years, particularly in biomedical
engineering — with application in defense industry — but has been
somewhat foreign in health care. A challenge with any imposed interface with
the human body is the compatibility between the wearer and the technology. It
appears the investigators in Taiwan are making advancements in BCI utilizing
external orthoses as the tool for control, via brain electrical potentials,
with possible application in rehabilitation medicine.
Certainly an area of great interest is in promoting adaptation of the
technology, particularly with regard to brain interface where the neurological
control system has been observed to exhibit remarkable adjustment to new
demands, via BCI. To advance the technology will require greater
multidisciplinary collaborations among clinicians, engineers and scientists.
Perhaps in the future, the profession of orthotics and prosthetics can
incorporate BCI as an expansion of scope of practice. Certainly, this would
require collaborations with other professions. It is not incomprehensible to
consider this type of collaboration as a possibility for the O&P profession
in the future.
— Christopher Hovorka, MS, CPO, LPO,
FAAOP
Director of Master of Science in Prosthetics and Orthotics
program, Georgia Institute of Technology
Often in working with the cerebrovascular accident upper limb patient I
see the frustration as the patients tries to communicate with the impaired arm.
As a practitioner who works in spasticity clinics, I often work with orthoses
designed to increase range of motion teaming up with modalities such as Botox
and Baclofen. The end result gives the patient the range to move through, but
often, weakness can prevent the patient from being able to make use of this
improved range. The key is the lack of ability to communicate with this
improved range to move the hand and fingers in the proper coordinated
direction.
What an exciting advance it would be to witness these patients then
having the ability to create a pathway of communication with the orthosis to
make use of the involved arm and hand.
— Keith M. Smith, CO, LO, FAAOP
President,
Orthotic and Prosthetic Lab Inc. and president, American Academy of Orthotists
and Prosthetists
