The bouncing laser beam interacted with the billions of exhaled molecules, identifying the entire composition of the breath. The findings were very precise, Ye said. One of the participants was a smoker, and his test revealed five times the normal level of carbon monoxide.
The beauty of the system, Ye said, is the fact that it sees the entire spectrum, not just a few specific molecules. And that's important because a single molecule would mean little.
"If you have asthma, your breath will have nitrous oxide, but nitrous oxide does not necessarily mean you have asthma," he said. "But if you see several different molecules all at once, and they are associated with asthma, then you have found a real fingerprint of a certain disease."
The technology is still in its infancy, and for now it appears to be limited to diseases that somehow involve the lungs. But Ye thinks that could change, and the applications could broaden, as the technology develops further.
The device can also differentiate between different isotopes, like carbon 12 and carbon 13, and oxygen 16 and oxygen 17, and changes in those ratios could also indicate the presence of a disease. The idea, Ye said, is to build a system that will allow the earliest possible detection in the least invasive manner at a price that everyone can afford.
The technology can now identify a single molecule among billions. The next goal will be to find a single molecule among trillions. That would broaden its application even further.
The researchers built their machine at their institute, located on the University of Colorado campus, at an estimated cost of $50,000. That, of course, does not include the millions spent on earlier research, or the cost of their time.
"Once it's mass produced, the cost could be quite low," Ye said. "It could be put into every doctor's clinic so people could walk in and do painless breath tests and then walk away. They would get results in a day or so."
Of course, all of this is based on lab research, and an experiment with a few college students. The technology has not been tested yet in the medical field. But Ye's office phones were ringing constantly during the interview, and some of the calls were from companies interested in moving the technology from the laboratory to the marketplace.
Lee Dye is a former science writer for the Los Angeles Times. He now lives in Juneau, Alaska.