Inhale, exhale and move forward 

New invention enables quadriplegics to maneuver 

Jerusalem Post
July 28, 2010
http://bit.ly/israeli-invention  

Quadriplegics like England’s Prof. Stephen Hawking who have 
difficulty even pressing buttons or moving a joystick will be able 
to navigate their wheelchairs and communicate with others more 
easily by inhaling or exhaling through the nose at a sniffing device 
invented at the Weizmann Institute of Science.

Prof. Noam Sobel, electronics engineers Dr. Anton Plotkin and 
Aharon Weissbrod, and research student Lee Sela developed the 
technology in the Rehovot institute’s neurobiology department, 
which announced the achievement on Tuesday.

The unique device could replace the more tedious technology of 
blinking one’s eyelids to choose letters and piece together words, 
use a computer or steer an electric wheelchair.

Sniffing technology, said the developers, might even be used in 
the future to create a sort of “third hand,” to assist healthy 
surgeons or pilots.

The new system identifies changes in air pressure inside the 
nostrils and translates these into electrical signals. After the 
device was tested on both healthy volunteers and quadriplegics, 
the results showed that the method is easily mastered.

Users were able to navigate a wheelchair around a complex path 
or play a computer game with nearly the speed and accuracy of 
a mouse or joystick.

“The most stirring tests were those we did with locked-in 
syndrome patients,” said Sobel.

“These are people with unimpaired cognitive function who are 
completely paralyzed - ‘locked into’ - their bodies.

With the new system, they were able to communicate with 
family members,and even initiate communication with the 
outside world. Some wrote poignant messages to their loved 
ones, sharing with them - for the first time in a very long time - 
their thoughts and feelings.”

Four of those who participated in the experiments are already 
using the new writing system, and the Weizmann Institute’s 
technology transfer arm, Yeda Research and Development 
Company, Ltd., is investigating the possibilities for developing 
and distributing the technology.

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 
several nerves that connect to it directly through the skull. 
This close link led Sobel and his scientific team to theorize 
that the ability to sniff - that is, to control soft palate movement - 
might be preserved even in the most acute cases of paralysis.

Functional magnetic resonance imaging (fMRI) provided 
evidence behind the idea, showing that a number of brain areas 
contribute to softpalate control. This imaging revealed a 
significant overlap between soft palate control and the 
language areas of the brain, hinting to the scientists that the 
use of sniffing to communicate might be learned intuitively.

To test their theory, the researchers created a device with a 
sensor that fits on the nostril’s opening and measures changes 
in air pressure. For patients on respirators, they developed 
a different version of the device, which diverts airflow to 
the patient’s nostrils.

About three-quarters of the subjects on respirators were able 
to control their soft-palate movement to operate the device.

Initial tests, carried out with healthy volunteers, demonstrated 
that the device compared favorably with a mouse or joystick 
for playing computer games. In the next stage, carried out in 
collaboration with Prof. Nachum Soroker of Loewenstein 
Hospital Rehabilitation Center in Ra’anana, quadriplegics and 
locked-in patients tested the device.

One patient who had been locked in for seven months following 
a stroke learned to use the device over a period of several days, 
writing her first message to her family. Another, who had been 
locked in since a traffic accident 18 years earlier, wrote that 
the new device was much easier to use than one based on blinking. 
Another 10 quadriplegics succeeded in operating a computer 
and writing messages via sniffing.

The device can also function as a sort of steering mechanism 
for wheelchairs: Two successive sniffs in tell it to go forward, 
two out mean reverse, out and then in turn it left, and in and 
out turn it right. After 15 minutes of practice, a subject who 
is paralyzed from the neck down managed to navigate a 
wheelchair through a complex route - sharp turns and all.

Sniffs can be in or out, strong or shallow, long or short; 
and this gives the device’s developers the opportunity to 
create a complex “language” with multiple signals.

The new system is relatively inexpensive to produce, Sobel 
suggests, and simple and quick to learn to operate in 
comparison with other brainmachine interfaces.