Even severely paralyzed people on respirators can do it: They can sniff. That is, they can at least partially control the movement of air through their nostrils. And if they can sniff, they can use this action to write on a computer screen or steer a wheelchair. That’s the principle behind a new device developed by Prof. Noam Sobel, students and electronics engineers in the Weizmann Institute’s Neurobiology Department.
After teaching healthy volunteers to play computer games using a “sniff control” in lieu of a mouse or joystick, the Weizmann team entered into collaboration with Dr Nachum Soroker at the Loewenstein Hospital Rehabilitation Center, taking their device to the hardest cases: quadriplegics and “locked-in” patients who have lost even the ability to speak. One locked-in patient used the device to communicate with her family for the first time since suffering a stroke seven months earlier. In another trial, after only 15 minutes of practice, a quadriplegic was able to steer his wheelchair around a challenging route. According to Sobel, learning to communicate by sniffing might be somewhat intuitive: Areas of the brain that control the movement of the soft palate, which directs airflow through the nostrils and mouth, overlap with areas for language.
Sniff control might come in handy for the non-disabled, as well: Sobel and his team envision “third hands” for pilots and surgeons that will be operated by sniffing.
Incidentally, in a second paper published in the same online issue of PNAS, another Weizmann neurobiologist, Dr. Elad Schneidman, teamed up with physicists at the University of Pennsylvania to investigate how the brain’s neural networks should organize to encode information optimally by achieving a balance between capacity and noise.