New devices coming to assist the disabled

When someone suffers a devastating injury, everyday tasks can become difficult, if not impossible. A person who loses an arm or hand can’t grip and turn a doorknob. For someone in a wheelchair, even a small step can block their way. But on February 15, researchers at a major science meeting described a host of new devices being developed to overcome such physical limitations. Many are now undergoing early testing. They won’t be for sale soon. But one day in the not-too-distant future, advanced versions of these devices could make life easier for many people.

Take, for example, someone who has lost the use of their hand. That’s a problem more common than most people realize, says Kyu Jin Cho. He’s a mechanical engineer at Seoul National University in Korea. About 500,000 people end up in a wheelchair each year. Of those, around half also suffer injuries to their hand, Cho notes. And that number doesn’t include the people who sustain injuries just to their hands.

To deal with this, Cho and his team have designed a glove made from a flexible, rubberlike material. It has three fingers that fit over the wearer’s thumb, index finger and middle finger. Wires attached to those fingers can be moved by a small motor. The motor, controlled by a simple switch, pulls on the wires to open and close the hand. The result is a glove that can help people grip objects.

Cho’s group call’s its invention the Exo-Glove Poly. Exo is from the Greek for “outside.” It refers to the fact that this glove is worn outside the user’s body. Poly, Greek for “many,” refers to the fact that the glove’s rubberlike material is a polymer.

Other researchers have designed gloves that pick up nerve impulses from a user’s arm muscles to help control a glove’s motions. But those earlier devices were relatively complicated. If produced, they would be costly, notes Cho. People who have tested the Exo-Glove Poly like its simplicity, he says. Another benefit: It’s waterproof. That means users can wash their hands or clean dishes while wearing it. The glove also can be removed and washed when it gets dirty.

This Korean team was among research centers describing new technologies, last week, for people with serious physical handicaps. They showcased their devices, here, at the annual meeting of the American Association for the Advancement of Science (AAAS).

Helping paralyzed legs pedal a bike

Some people suffer spinal injuries that cause their arms or legs to become paralyzed. In many cases, the injury severs connections between nerves in the arms or legs and the spinal cord or brain. Now when the brain tells the limbs to move or the nerves’ pick up a sensation of pain, that message can’t get through to its target, notes Ronald Triolo. He works at Case Western Reserve University in Cleveland, Ohio, as a biomedical engineer. These researchers use science and math to create things like medical devices.

Triolo’s team is looking to assist the nerves and muscles that remain healthy but are no longer connected to each other. To do that, they have designed an electronic device to stimulate the nerves. It’s similar to the way a pacemaker zaps a heart to trigger its contractions. Their device instead triggers leg movements.

The first step involves surgery to implant electrodes next to nerves in the paralyzed leg. Doctors can then send small electrical impulses to make one or more muscles contract. With just one electrode, doctors can make a muscle trigger a simple motion.

Actions such as walking, or opening and closing a hand, however, are very complex. They require the coordinated motions of many muscles. Not only would many switches be needed, but they also would need to be stimulated in a precise sequence, or pattern. That means a simple on/off switch like the one used in Cho’s Exo-Glove Poly wouldn’t be suitable to help someone walk. Instead, a person would need a small computer.

To read the rest of this article, published in Student Science, please click here.