Locked-in patients may be able to drive wheelchairs and surf internet by breathing

Scientists at the Weizmann Institute of Science in Rehovot, Israel, are testing a “sniff detector” that is able to pick up pressure changes in the wearer’s nasal cavity and convert it into electrical signals. The device can then be hooked up to special software and used to move a curser on a computer screen or control a wheelchair.

The device was tested on three people with locked-in syndrome, a paralysis that “locks” a fully intact mind into a paralysed body. One patient, a 51-year-old woman who was left unable to move, speak or blink after a stroke, was able to communicate for the first time using the new technology. After 19 days learning to produce a sniff on demand with 20 minutes of practice a day, she was able to write her family a message for the first time. To this day, the “sniff detector” remains her only means of expressing herself.

Another man, who had been "locked in” for 18 years following a car accident, wrote his own name within 20 minutes of using the device. Eleven other quadriplegics were also able to drive a wheelchair and surf the internet using the detector.

Noam Sobel, a neurobiologist at the Weizmann Institute, developed the device almost by accident. Dr Sobel, who usually studies the way the brain processes the sense of smell, said they came up with the idea after using a sniff-triggered olfactometer - a device that produces waves of smell.

“We noticed that sniffs are a very good and fast trigger," he told the US science publication Discover Magazine.

“It then simply dawned on us that instead of triggering odour, we could trigger anything: letters in a text writer or turns of a wheelchair. The rest just flowed or rather, rushed from there.”

Niels Birbaumer, at the University of Tubingen in Germany, said he was doubtful the sniff detector would work for completely locked-in patients. He told New Scientist Magazine that fully locked-in patients would not have enough control in their muscular system to work. Dr Sobel responded by saying the system was still in its development stages.


/Telegraph.co.uk/