(Courtesy of Carleton University Magazine)
People around the world ask the same question on a daily basis: “Is the milk bad?” A quick sniff gives us a fast and reliable answer. The sense of smell is very powerful and often taken for granted. We simply follow our nose, because it always knows…but so does an electronic nose (e-nose).
E-noses, first developed in Britain in the 1990s for use in the food industry, mimic the olfactory system by using a series of sensors that can be trained to detect specific odors and even bacteria that may be present in the food we eat.
Adrian Chan, associate professor in the department of systems and computer engineering, sniffed out an opportunity to develop such a nose in partnership with the Canadian Food Inspection Agency (CFIA). With outbreaks of food-borne illnesses making headlines across the country—E. coli, Salmonella and Listeria—it is a natural partnership that presents many public health benefits.
“We are working with the CFIA to develop an e-nose that can rapidly detect and identify bacteria,” says Chan.
The current testing system—in which a food sample is sent to a lab where a trained technician cultures bacteria from the sample and then studies what grows—is time consuming and expensive; thus, under the current system screening is typically performed using random samples.
“If we can develop something that is cost effective and tests continually rather than randomly, then we can test everything and detect a problem immediately, well before contaminated food gets consumed,” explains Chan.
“With samples from the CFIA, we now know that the e-nose can detect and identify E. coli and Listeria,” says Chan. “The next step is developing techniques and system robustness that will differentiate bacterial species and their concentrations.”
Chan is quick to point out that applications for the e-nose aren’t limited to detecting food-borne bacteria. “Eventually, we want to look at whether an e-nose can detect diseases or be used for continual monitoring of wounds to detect infection,” he explains.
The e-nose can also be used to monitor behavioral patterns of everyday living. Smart environments, as they are called, have sensors embedded throughout that are connected through a network that provides remote monitoring. One such example is the “smart apartment”—an Ottawa-based research partnership in which Carleton is involved—in the Élisabeth Bruyère Health Centre.
“Smart environments can support older adults or recovering patients in their home,” says Chan. “The electronic nose can detect everyday activities like cooking and cleaning, and can alert caregivers to alterations in routine, or to problems of health and hygiene. This is non-obtrusive compared to methods that use video cameras.”
Certainly, the potential applications are as varied as the number of smells in the world. “There is a report of a dog that could determine whether a person had cancer by smelling,” says Chan. “Imagine the utility of e-noses. They could have many applications.”