People who suffer from chronic obstructive pulmonary disease have bronchial cilia in their lungs that produce too much mucous. Acoustics engineer Sandy Hawkins has developed a flute that produces a sound that dislodges excess mucous in the lungs. In Popular Science, Corey Binns writes:
http://www.popsci.com/bown/2009/innovator/pied-piper-mucus | Video of the flute in use | Image: Popular Science
Hawkins began building an electronic sound machine that would produce waves of 16 hertz—the same frequency at which the cilia move—to help break up the mucus. Generating a hum of such a low frequency normally requires van-size subwoofers, and so he spent 15 years honing and shrinking the speakers. Then one day as he was testing a mouthpiece filter for his machine, he noticed that blowing through it sent a slight vibration into his chest. Within five seconds, he sketched out the Lung Flute to amplify the effect. Blowing into the tube flaps a reed-thin sheet of plastic, which vibrates the chest and shakes the mucus until it’s thin and mobile enough for the cilia to usher it up your throat. “I felt so stupid because the answer was so simple,” Hawkins says.
Today, doctors in Japan use the $40 Lung Flute as a tool to collect sputum from patients suspected of carrying tuberculosis, and in Europe and Canada it’s used to help test phlegm for lung cancer. Clinical trials in the U.S. have shown that it is at least as effective as current COPD treatments. At press time, Hawkins expected the device to receive FDA approval any day, and says the reusable device could also provide home relief for patients with cystic fibrosis, influenza and asthma.
http://www.popsci.com/bown/2009/innovator/pied-piper-mucus | Video of the flute in use | Image: Popular Science
And the mucus/mucous correction is irrelevant as the contents may be blood, serous or something else - not just mucus. Once it's passes the throat it's sputum. Yum.