Japanese Team Develops Brain-controlled Wheelchair

Japanese car giant Toyota and Riken, a think tank under Japan’s Education and Science Ministry, announced yesterday their joint development of an electronic wheelchair steered by brain signals.

The humanoid wheelchair moves by analyzing brainwaves of its driver. The thought of grasping the right hand makes the wheelchair go right, for example, and it moves forward if the rider thinks of foot movement. If there is no thought of movement, the wheelchair stops.

A driver`s brainwaves are transferred to a built-in computer through five electrodes in the helmet the driver wears. The computer translates the brainwaves into instructions to steer the motorized wheelchair. A mechanism moves the wheelchair when the driver thinks of movement of the left hand, brainwaves on the right side of the brain decline, and vice versa. When the driver imagines him or herself walking, the width of brainwaves in the central motor cortex declines. In an emergency, the wheelchair immediately stops when a driver moves a cheek muscle.

The system is said to be 95 percent accurate.

The whole process from thinking to brainwave analysis takes only 125 milliseconds. The researchers significantly reduced the previous analysis time of several seconds by developing a signal process technology that can analyze weak brain signals.

The breakthrough was led by professor Choi Kyu-wan, a graduate of Korea University in Seoul who earned his doctorate from Tokyo Engineering University, and Andrzej Cichocki of Poland.

The new technology is expected to be used in health care and welfare for the elderly and applied to robots and electronic appliances.

jkmas@donga.com