A new communication device controlled by sniffing is allowing victims of strokes and other severely debilitating trauma to write letters to family and express everyday thoughts.
The nasal-controlled technology developed by scientists at the Weizmann Institute in Rehovot, Israel, uses a pressure sensor attached to the end of a nasal tube for detecting the opening and closing of a person’s soft palette.
By connecting the sensor to a computer, a person wearing the device can use sniffs to select letters on a screen to build up words and sentences.
Research leader Noam Sobel, of the neurobiology department at the Weizmann Institute, said the technology could also be used to drive electric wheelchairs.
Sobel added that the advantage of this technology is that it can be used by those with disabilities ranging from quadriplegia to locked-in syndrome. In the case of the latter, patients are completely paralysed but retain enough cognitive ability to sniff with precision.
Sniffing requires precise movements of the soft palate, which receives signals from cranial nerves that are often unaffected by paralytic injury and disorders.
Sobel explained the device works even if a patient has been given artificial respiration because it functions regardless of air pressure source.
‘With patients who are artificially respirated, our system has an addition of a small little pump that pressurises the nose at three litres per minute,’ he said. ‘If you open your soft palate, pressure drops. If you close your soft palate, pressure increases, and we measure that and generate the signal. It’s actually even faster.’
When testing the device with healthy and quadriplegic participants, the team found that subjects were able to manipulate the sniff controller as quickly as a computer. More severely disabled patients took a minimum of 20 seconds to select a letter.
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.
Sobel said that building up words and sentences can be achieved quickly with word completion software, which had to be built bespoke for the Weizmann Institute tests because there was no readily available Hebrew version on the market.
The technology would likely be inexpensive to manufacture, Sobel added, pointing out the systems built for the lab cost approximately $300 (£194).
‘I assume that if and when somebody picks this up and goes into mass production it will cost a fraction of that,’ he said.
The Weizmann Institute is currently looking for an appropriate partner to license the technology and manufacture it for the mass market.