"Science Daily — A new medical device in development by University of Cincinnati researchers may sniff out olfactory disorders that could be an early warning of Alzheimer’s disease, Parkinson’s disease and other problems outside the typical sensory loss associated with aging."
"In humans, Frank says the sense of smell is one of our less robust senses. He says it’s more susceptible to harm because there is less neurological machinery in the brain devoted to processing the sense of smell. “So, that’s the reason it might be acting a little bit like the canary in the mineshaft. Because it’s more fragile, when you have insult to the brain, it may be sensitive to loss earlier in the disease process.”This actually sounds pretty well thought out. It's a matter of detecting the smells, not necessarily recognizing or naming it. For the young, it's a method of detecting olfactory disorders or deficiencies. For the old, the hope is that it will also detect brain damage earlier. To determine whether you have really smelled the odor, it measures the size of your 'sniff'.
“For someone with normal sense of smell, the size of the sniff when detecting an odor is cut in half. For someone who cannot detect odor, the size of the sniff for just air and the size of the sniff for an odor are the same.”http://www.sciencedaily.com/releases/2007/04/070402153233.htm