Diagnosing disease, the old-fashioned way

by Tara Smith     Department: Technology

A medical doctor I worked with during graduate school used to regale us with tales of odd ways to diagnose disease. Cystic fibrosis, for instance, causes afflicted children to taste salty, as they have higher than normal amounts of sodium chloride in their sweat. Diabetes causes increased sugar in the urine, making it taste sweet and smell something like honey. Even specific bacterial infections can each have distinct smells. A new article in Scientific American takes this idea--diagnosis by senses--and describes how it's being developed into a new technology that may even be able to detect cancer:

Enter the electronic nose, an emerging technology that can distinguish these subtle differences. There are a variety of electronic e-nose models, all of which consist of an array of olfactory sensors that are activated in unique patterns when exposed to different aromas; software identifies each odor and its source by analyzing the patterns. (The human brain uses this same pattern-recognition process to identify smells.)

Though the technology was originally designed for other tasks, such as sniffing out chemical leaks or detecting food spoilage, research is increasingly revealing its diagnostic potential. Physicians can effectively identify potential lung cancer patients, for instance, by "smelling" their breath.

"When you have an exhaled breath, there are all sorts of volatile organic compounds that are produced," says Serpil Erzurum, a pulmonologist at Cleveland Clinic and co-author of a 2005 study on the use of electronic noses to help diagnose lung cancer. "Those compounds are a result of metabolism and, when you have cancer, metabolism changes and the volatile organic compounds are altered. The changes are detectable by an electronic nose."

The article notes that this technology may even be able to "sniff out" antibiotic-resistant infections right from the patient--bypassing the need for culture and resistance testing.

Such "technology" has been tried previously using dogs to sniff out cancer; this new twist on scent-as-diagnosis is just a bit more sophisticated and, ideally, takes less training (and housebreaking!).

Tags: diagnosis, disease, technology