Senate hearing features new prosthetic hand
From: VA Research Currents - May 2006 - page 1

The highlight of an April 27 Senate hearing on VA research was the
demonstration of an innovative prosthetic hand being developed by Richard
Weir, PhD, an engineer at the Chicago VA Medical Center and Northwestern
University.

Weir demonstrated a partial hand prosthesis, designed for those who have a
wrist but have lost their fingers and thumb. The myoelectric unit has a
built-in controller that interprets electrical signals from residual muscles.
After Weir attached two electrodes to flexor and extensor muscles in the
forearm of Committee chairman Senator Larry Craig (R-Idaho), the lawmaker was
able to use the hand to hold a glass of water. Weir explained how users know
how much force to exert when grasping an object: "The hand has no pressure
feedback, and if it were ‘pushed’ it could crush a glass. But it must be
pushed to do so. Usually, the user controls a myoelectric hand by using
vision to see how the fingers are ‘deforming’ around an object. In addition,
the motors change pitch as they work harder, and users get used to that."

Weir's lab has teamed with a commercial manufacturer to produce several
pre-commercial prototypes for clinical testing.

"We give users instructions to take it home and let us know when it breaks -
we expect it to break once users do things with it we never predicted, so we
want to find that out and iteratively make the mechanism tougher and able to
withstand the rigors of everyday use."

While the partial hand prosthesis only opens and closes, Weir's team and
collaborators at other institutions are developing a more sophisticated
prosthesis they hope will move and function almost like a natural hand. The
idea is to use implantable sensors to receive input from all 18 forearm
muscles involved in controlling the human hand, and develop fuzzy logic to
translate those signals into mechanical movements that match the user’s
intent. Biomechanics expert Wendy Murray, PhD, at the Palo Alto VA is helping
to map out those functions.

Read the entire article at:
http://www1.va.gov/resdev/resources/pubs/docs/va_research_currents_may_06.pdf

Full text of the hearing is available at:
http://veterans.senate.gov/index.cfm?FuseAction=Hearings.CurrentHearings&rID=591

View the hearing at:
http://veterans.senate.gov/archived_va_research.ram

Photo Gallery
http://veterans.senate.gov/index.cfm?FuseAction=Newsroom.Gallery&album=54

Richard Weir
http://www.bme.northwestern.edu/faculty/fac_affiliated_weir.shtml

Wendy Murray
http://guide.stanford.edu/People/murray/murray.html

Is a bionic arm within reach?
http://chicagobusiness.com/cgi-bin/news.pl?id=19734