The Phone of the Future Will Monitor Your Health By Smell

Building an electronic nose packed with enough sensors to mimic the versatility of a biological snout isn't cheap at the moment. The human olfactory system, for example, contains millions of olfactory receptor neurons (ORNs).

According to new research, however, combining small numbers of finely tuned receptors could one day make an e-nose affordable enough to pack into a smartphone.

Biologically-inspired e-nose prototypes like the Cybernose—which takes the nematode as its animal analogue—are extremely costly, due to their large numbers of ORN-like sensors. To overcome this limitation, a team of scientists led by Thomas Nowotny at the University of Sussex tested the ability of fruit flies to detect wine and "industrial" scents (i.e. drugs and bombs), and isolated the ORNs responsible for specific kinds of scent detection.

Their approach, described in a paper published yesterday in the journal Bioinspiration & Biomimetics, involved running thousands of identified ORN combinations through a machine learning process that trained the receptors to recognize different smells. This process revealed which receptor combinations were best suited for identifying different things—really good weed, a skunky cabernet, or a deadly explosive, for example.

"For the wine, there would be ten receptors that were really good together to recognize the wine, and for the explosives, there would be ten others that would be good together to recognize explosives," Nowotny told me. "We could then make sense of it using machine learning methods to say, ah, but these five together would make a really good nose to detect these explosives. And these ten together would be really good for wine."

According to Nowotny, this finding could represent a significant step forward for e-nose technology, since it opens the door for developing smaller, more specialized devices that could eventually be affordable enough to become mainstream consumer technology.

"You could make the instruments more lightweight that way," Nowotny said. "The computation, as well. With less components, less can go wrong, and you need less computation power. I'm confident that with a modern phone, you could do everything you need. An e-nose could easily be a set of sensors plugged into a modern cell phone and there you go, with just a little bit of software."

Current generation e-noses have been used to detect the presence of illnesses like mesothelioma and lung cancer on a patient's breath. If e-noses ever become cheap enough to put on a smartphone, as Nowotny believes, we could be living in a world where our phones can monitor or health—and serious stuff, not just how many steps you took today—just by odor.

"There's a lot of work ahead on that front, but with the sensors coming along, you could certainly imagine that—a personal health monitor," Nowotny said. "That would be amazing, right? If people could breathe into a phone every day, and they could have a very early warning for lung cancer."

Huge amounts of research and development have to be undertaken before this vision becomes a reality. The idea and basic mechanics are there, but adequate hardware and software have to be developed before you can blow into your phone every morning to get a bead on your health.

The team behind Cybernose, which uses an approach similar to Nowotny's, is still working out the kinks in their own prototype. Even so, Nowotny is optimistic about the possibility of this technology to taking off, which he estimates as being likely within the next decade. The phone of the future could very well smell.