"Wearable" robots: It’s about more mobility

Supplier: Maxon Motor - Medical & Surgery By: MMAG
28 May, 2010

How "wearable" robots assist people with restricted mobility with the help of maxon drives.

The first motor-driven exoskeletons originated in Japan ,and should also come to market in the near future in the West. Then the adventures of the comic book and movie hero Ironman will move that much closer to reality.

The Japanese company Cyberdyne created an artificial, powered exoskeleton named HAL-5 that weighs 23 kilos and is equipped with all types of sensors, maxon electric motors, measuring devices and a small computer. HAL stands for Hybrid Assistive Limb and is designed to enable the wearer to compensate for physical handicaps or transport heavy loads.

The robot suit is slipped on the body similar to a knight's armor. maxon DC motors and sensors, hidden under white plastic splints, are fixed to the arms and legs, and a type of harness is pulled over the breast. The battery, which lasts almost three hours, is attached to the belt.

The bio-cybernetic control of the machine depends on the sensors attached to the skin and tap into the existing signals of the nerves. The attached computer assesses the signals and recognizes whether the wearer of the suit wants to move or stand still. If he wants to take a step forward, for example, the calculator gives the hydraulics of the mechanical legs a command to alter the delay angle of the corresponding joint. The brushless maxon DC motors react to this impulse in a fraction of a second, almost as quickly as the body's own nervous and muscular system reacts to signals from the brain.

The ever-aging populations of industrial nations as well as people with limited mobility will have important uses for such developments.

In contrast to futuristic whole-body suits, therapeutic robots that assist people with relearning important movements are already in use in Europe. The Lokomat from Hocoma, for example, is a therapy system powered by maxon motors that supports disabled patients suffering from neurological diseases or injuries in treadmill workouts and helps them regain the use of their legs. Along with the physical actions of the therapist, it permits longer and more intensive training sessions and therefore better therapy results.