Doctors since ancient times have been able to detect ailments from the smell of a patient's breath, and the practice is now getting a boost from 21st-century technology, the Wall Street Journal finds. Researchers are identifying thousands of compounds that leave traces in exhaled breath and developing tools that can diagnose and monitor a large number of illnesses by requiring patients to do nothing more than blow into a machine. In some cases, fast, painless, and cheap breath tests can provide more information than blood tests.
"The Holy Grail is the Star Trek Tricorder concept, where you would breathe into a device and a sign would pop up saying what health problems you have," says a professor of mechanical and aerospace engineering who is developing an asthma monitor for children. That goal may still be quite a few years away, but large numbers of breath tests are now in the research stage and experts say the field is advancing so rapidly that exciting developments could make their way into doctors' offices within the next few years.