July 26, 2010 -- Israeli scientists have developed a device that allows severely disabled people to sniff to precisely control objects such as wheelchairs and personal digital assistants, a new study says.
The nasal-mask device works so well that disabled people who can’t move at all can learn to write text messages and drive electric wheelchairs by sniffing, researchers report in the July issue of Proceedings of the National Academy of Sciences.
Noam Sobel, PhD, of the department of neurobiology at the Weizmann Institute in Israel, and colleagues set out to find a way to allow people with disabilities ranging from quadriplegia to “locked-in syndrome” to learn how to control devices with their noses just as they would using a joystick or computer mouse.
The Weizmann Institute has filed for a patent on sniff-controlled technology, which the researchers report as a possible conflict of interest.
The researchers built a “sniff controller” that measures changes in nasal pressure, which occur when the soft palate (the soft area at the back of the roof of the mouth) is repositioned. The device was tested on healthy and disabled people. The researchers report that sniffing can be done with precision, and that it requires precise movements of the soft palate, which receives signals from cranial nerves that often are not affected by paralytic injury and other disorders.
The study involved 96 healthy and 15 severely disabled people who were taught to sniff in different ways to send various electrical signals to a controller. For example, two in-sniffs meant forward, and two out-sniffs backward. Various sniffing sequences allowed participants to turn and steer a wheelchair.
In the end, a quadriplegic person could use the sniff controller to drive an electric wheelchair with precision after only 15 minutes of practice, the study says.
The researchers report that healthy people played computer games with the device as adeptly as they might with a mouse, joystick, or other controller.
Quadriplegic patients managed to use computers to write text messages and learned to control electric wheelchairs as well as the healthy people taking part in the research, the study says.
People who are “locked in” -- completely paralyzed but cognitively intact -- also were able to use the device to produce text messages.
One woman communicated for the first time in seven months, and another wrote for the first time in a decade, the researchers say.
Researchers say the device now awaits testing in disorders of consciousness, including the vegetative state.