|The i-Limb, made by Touch Bionics, is one of the more advanced prosthetic hands.
Its makers claim its the world's most advanced bionic hand. Whilst this claim
does not hold water, it is certainly, at time of release in mid 2007, one of
the most advanced hands, although not the most advanced - that honour goes
to a DARPA military development.
The I-Limb is the first commercially available tactile gripping hand however. It works on the usual myoelectric system, which uses electrodes to detect electrical signals from muscles and translate them into movement, but also uses tactile feedback to tell when it has a good grip. A bionic hand keeps going, and can crush delicate objects. The i-Limb hand has stall-detection, which tells the
hand when it has exerted enough pressure.
i-LIMB acts like a real human hand, even if, as the image above shows, it is
not all the way there in the visual department yet. A few visual problems:
- All the knuckles on the fingers hold at exactly the same angle, like a mannequin's
- Skin is very close to realistic, but not quite.
- Lack of tendon tension does not aid realism.
- Fingernails do not look right.
That said, the I-Limb is a 10-fold improvement, quite literally, on devices
available just one year ago.
"We are delighted to be the company that moves bionic hand technology
from the research and development phase into the real world, and to lead a
generational advance in bionics and patient care," said Touch Bionics
CEO Stuart Mead. "We have always existed to change the lives of patients
with severe injuries and disabilities, and it is thrilling to feel that we
are now able to accomplish that goal."
The manufacturers are still working on perfecting the skin's appearance, and
have acknowledged the potential defects above.
"Cosmesis is a hugely important area in prosthetics, both for appearance
and for durability reasons. It is a vital component of our solution and brings
an added dimension of personal comfort and satisfaction to our patients,"
said Mead. "Some patients, especially soldiers, love the more robotic
look of the i-LIMB Skin, but others like their device to blend anatomically
with the rest of their body, and prefer to have a life-like covering for the
i-LIMB Hand and ProDigits."