Dr. Baltzer works in collaboration with a rehabilitation medicine specialist, Dr. Amanda Mayo, to give people something better: the myoelectric prosthetic, an artificial hand that takes signals from a person’s muscles and transmits them into multiple movements at once. With this hand, people can lift a beverage to their lips or even carry a suitcase.
Specialized surgery
Not everyone has access to the myoelectric prosthetic. For someone to get one, they must undergo a special procedure Dr. Baltzer performs. This surgery prepares a patient’s body to work with the device, because after any amputation, severed nerve endings continue to grow “like a salamander’s tail,” she explains. The nerve endings form painful little balls called neuromas, which make it difficult to wear any kind of prosthetic.
227,000
Canadians living with a limb or extremity amputation
(SOURCE: ACTIVE LIVING ALLIANCE)
Dr. Baltzer surgically removes these neuromas and redirects the nerve endings to a muscle in the remaining upper arm, which boosts the muscle’s electrical signal. (Muscles and nerves work together to generate electricity that allows bodies to move.) That electrical signal can be detected on the skin and is then picked up by a sensor inside the prosthetic. “So, when your brain tells your hand to flex, even if it’s not the muscle that was supposed to make your fingers flex, it gives that signal,” says. Dr. Baltzer.
More sensory feedback
While myoelectric hands are a step up from the older models, they’re still not perfect – they can’t give sensory feedback to the brain, which makes it harder to grasp something delicate, like an egg, without crushing it.
So, Dr. Baltzer is bringing together several Toronto-based experts to design inexpensive prosthetics that meet this need. “Sensory feedback will make patients feel that this is really their hand,” she says. “You need to look toward the future. You need to offer hope.”
