The University of New Brunswick (UNB) Institute of Biomedical
Engineering hosted the myoelectric control (MEC) symposium from Aug. 17 to 19,
gathering international researchers, practitioners, engineers and leaders in
upper extremity rehabilitation from 14 countries. Adam
Clawson, lead mechanical project engineer for the UNB, discussed how these
experts are attempting to push the boundaries of modern technologies to enhance
the life experience of end users through multi-functional and raised clinical
standards.
Essential Functions
Clawson, along with all of the engineers and designers at the symposium,
acknowledges that not every movement from the human hand is necessary for human
living. The challenge for engineers is to determine and then replicate the
essential functions of the human hand. Clawson is currently working on a
project at UNB and funded by Atlantic Innovation Fund, that offers users the
additional flexibility and a different style of a prosthetic hand, but at an
affordable price.
 |
|
| Adam Clawson |
“There is a certain amount of flexibility in the human hand that is
redundant,” Clawson told O&P Business News. “Current
commercial multifunctional hands have independent motion of each finger. The
costs of a motor to drive that flexibility of the finger increase the price of
the hand. Using novel gear systems and thinking of the hand in a different way,
we can incorporate mechanisms that create systems such as a single motor to
drive not one finger but three fingers — the middle, ring and
little.”
If the middle finger were to stop, the user would likely want the ring
and little finger to continue and equalize the force for all three fingers.
Incorporated within the design of Clawson’s UNB Hand is a compensatory
mechanism that allows the hand to provide the same conformal gripping that the
user would find with existing commercial hands, but with a smaller price tag.
One motor controlling three fingers is lighter, cheaper and does the same
amount of work as three motors. Using this technique, Clawson has added
additional essential motions in the thumb that are not commercially available
as of press time. The UNB Hand is currently in its third version and will be
moving to clinical testing within the year.
Raised standards
“The main goal of the symposium is to discuss new technologies and
clinical techniques that can ultimately raise the standard of clinical service
that we can provide to the upper limb amputee,” Greg Bush, research
prosthetist for the UNB, told O&P Business News. “We
strive to offer our patients the best prosthetic solutions possible. This
includes mixing and matching components from various manufacturers. When we
have this freedom, it opens up opportunities for better utilization by the
user. This is all about offering solutions and options.”
The slogan for this year’s symposium was “Raising the
Standard.” The final panel discussion of the symposium highlighted the
ways in which upper extremity researchers, engineers and practitioners can work
toward that goal.
“As we develop more complex hands, we find it will be necessary to
get the many different components to work seamlessly.” Bush said.
“Raising the standard also means that we must create open standards for
all aspects of limb design and rehabilitation.”
According to Bush, an open standard would allow a prosthetist to order
different devices from different companies and have the confidence to know the
technology will work seamlessly and communicate together. This is a standard
practice in the automotive industry.
 |
|
| Adam Clawson said that the challenge for engineers is to determine and then replicate the essential functions of the human hand. |
|
| Image: Adam Clawson |
“For example, a prosthetist can order electrodes from company A, a
controller from company B, a hand from company C and a wrist from company D and
they will have the best possible prosthetic solution for that individual
patient,” Clawson said. “There is no standard amputee. We want to
create devices that are both mechanically and clinically suitable for the
patient.”
Advanced technology
According to Clawson, motor designs, as well as the miniaturization of
components are pushing forward the development of upper extremity artificial
limbs. The current version of the UNB hand utilizes bearings from remote
control helicopters. Small components from other industries are reliable and do
not put a major dent in the overall budget of the hand. The upper extremity
industry is small and if researchers and engineers can leverage technology from
another source, it will likely drive down the cost of the device for the user.
“We are always trying to find the best possible components for the
most cost effective price,” Clawson said.
Just a few years ago, engineers would not be able to fit advanced
components and technologies into a prosthetic forearm, but now are utilizing
techniques and methods of fabrication that are miniaturizing the components and
controllers. engineers are finding that the components and controllers are
shrinking. The miniaturization of technology, specifically controllers are
pushing the upper extremity industry forward. — by Anthony Calabro
The MEC is a more multidisciplinary conference particularly suited for
engineers and researchers who are involved in what will ultimately become the
next generation of upper limb prostheses.
 |
|
| Jack E. Uellendahl |
I have been to every symposium since 1989. The attendance has grown a
lot and it attracts an international audience. It used to be annual event, but
the travel can be draining for those international practitioners, so they
decided to hold it every 3 years.
I think attendance will continue to grow somewhat. It is difficult to
say how much it will grow because of the small size of upper limb prosthetics
in general. It will attract folks who are primarily interested in the upper
extremity and who are trying to expand their knowledge in that area.
— Jack E. Uellendahl, CPO
Upper limb
specialist, Hanger Orthopedics Inc.
This is a meeting I look forward to every time it comes around because
it is incredibly focused. It used to be specific to upper limb myoelectric
control, but within the past few meetings, the scope has opened up a little
bit. The organizers have broadened the scope to focus on related areas
including lower limb myoelectric control and different socket designs. In
addition, there has been a big push in the area of occupational therapy, which
makes the meeting relevant to not only prosthetists but the therapist community
as well.
The MEC Symposium is a great meeting in that it is usually attended by a
smaller group. The intimacy there is valuable and there is ample time for face
to face discussion with your colleagues. People come from all over the world,
so it is a great opportunity. It is certainly something readers should know
about.
— Todd Farrell, PhD
Senior research
engineer, Liberating Technologies
