Hand movement for stroke victims now possible

Dr. Arthur Prochazka and Richard hanes

Imagine going through life with one hand tied behind your back, trying to cook dinner, zip up a jacket, open a tin can or put the cap back on the toothpaste tube. It may not sound like a big deal, but it is for about three million people in North America (300,000 in Canada and 10,000 in Edmonton) who suffer from hemiplegia, or one-sided paralysis, due to strokes and other brain attacks.

Richard Hanes, 47, knows what it's like. He suffered a stroke 12 years ago while driving to Eastern Canada on vacation. While stopped at a gas station in Brandon, Man., Hanes fell to the passenger seat, unconscious. He slipped into a coma and woke 10 days later in a Winnipeg hospital with no memory, no speech, no movement on the right side of his body. About seven years of therapy has helped him to walk and talk again. But he still could not use his right hand. Until now.

Thanks to a device called the impact cuff, a form-fitting garment and muscle stimulator worn on the forearm, Hanes can open and close his usually tightly clenched right hand. "It's amazing," says Hanes. "It means a lot."

The impact cuff, developed by Dr. Arthur Prochazka, a professor in the physiology department of the Faculty of Medicine and Dentistry, has two internal electrodes carrying an electrical current from one to the other and to a built-in controller/stimulator box. The box generates 30 pulses per second, each pulse about 30 volts, which the wearer feels as a vibration. "The microprocessor in the box generates a pulse train to do whatever it's told to do," says Prochazka. In this case, it stimulates the nerves to direct the appropriate muscles to either open or close the hand.

The cuff contains an accelerator, a mechanism to detect jarring, adds Prochazka. It can be activated by tapping the box, or the forearm, with the other functioning hand. The accelerator used in the prototype Hanes wears can detect impact on three axes: x,y,z, says electronics technician, Al Denington. Denington and electrical engineer Debby Gillard are working to optimize the design, make the impact cuff smaller with a longer battery life and contained in a more comfortable garment. Unique in the world, it is the only self-containing device to aid hand movements for victims of stroke, says Prochazka.

More important, the impact cuff has an exercise mode. It can stimulate the muscles every five seconds automatically to open and close the hand. Typically, users of the cuff do the exercise for 20 minutes each day. "Nearly all of them report their hand is much looser," says Prochazka. This helps prevent the hand from contorting and damaging joints, which sometimes means surgery. In fact, one fifteen-year-old user of the impact cuff says surgery is no longer necessary to correct her contracted hand and she can continue to push wheelchairs in the nursing home where she works, says Prochazka.

The impact cuff does not cure the stiffness or paralysis, nor will it give the affected hand greater control after extended use. "This is just a tool," he says. "It needs to be used in physiotherapy clinics as part of whole-arm exercises. If [stroke victims] are taught to reach out and their hand is closed, there isn't much point. But if they are taught to reach out and their hand is open, they have more motivation."

The impact cuff will be marketed through Neuromotion Inc., a University of Alberta spin-off company based in Edmonton and Minneapolis, and should be on the market in about a year.

Neuromotion is also developing the tetron glove, a similar device for quadriplegics. It uses their ability to flick their wrists to stimulate hand muscles and assist movements. One American was eager to test the tetron glove, says Prochazka, only to use a gun against the person who caused his injuries.

He was turned down.

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