A sniffing-based device developed at the Weizmann Institute of Science in Israel may enable disabled people to navigate wheelchairs or communicate with loved ones. The system identifies changes in air pressure inside the nostrils and translates these into electrical signals. In the future, researchers predict that this technology may even be used to create a "third hand" to assist healthy surgeons or pilots.
Sniffing is a precise motor skill that is controlled, in part, by the soft palate - the flexible divider that moves to direct air in or out through the mouth or nose. The soft palate is controlled by nerves that are connected directly to it through the braincase. The researchers based the design of the device off the premise that the ability to sniff might be preserved even in the most acute cases of paralysis. Functional magnetic resonance imaging supported this idea, and also revealed a significant overlap between soft palate control and the language areas of the brain - indicating that the use of sniffing to communicate might be learned intuitively.
To test this theory, the scientists created a device with a sensor that fits on the nostril's opening and measures changes in air pressure. Quadriplegic patients testing out the device succeeded in operating a computer and writing messages through sniffing. In addition to communication, the device can function as a steering mechanism for wheelchairs. Testing of the device on healthy volunteers and quadriplegics has shown that the method is easily mastered. After 15 minutes of practice, a subject who was paralyzed from the neck down navigated a wheelchair through a complex route as well as a non- disabled volunteer.