Infrared cameras show promise as sleep apnea tool

An experimental infrared camera may be able to detect breathing problems in people with sleep apnea, taking at least some of the discomfort out of diagnosis of this chronic sleeping disorder, U.S. researchers said.

Diagnosis of sleep apnea -- a breathing interruption that disturbs sleep -- currently involves attaching a network of electrodes to the head, face, chest, abdomen and even some inside the nose, and then asking people to fall asleep in a sleep lab.

"You wind up with in excess of 20 electrodes," said Dr. Jayasimha Murthy of the University of Texas Health Science Center in Houston. "That can affect the way you sleep."

He said some people who take these tests lie flat on their backs for fear of disturbing the electrodes, but this could actually make apnea worse. "You could be overestimating disease just by your test," Murthy said in a telephone interview.

Instead, he and colleagues devised an imaging system using a remote, infrared camera that can track a patient's breathing during sleep. The camera monitors changes in heat signals released when people inhale and exhale -- data that is used to detect breathing disturbances.

"Our thinking right now is a complete shift in paradigm -- trying to think about non-contact sensors so we can take away at least some of the electrodes to make it more comfortable," said Murthy, who presented his results at a scientific meeting of the American College of Chest Physicians in Chicago.

Obstructive sleep apnea -- the most common type -- occurs when breathing stops during sleep, a process that can be repeated hundreds of times a night.

In adults, it typically results when tissues in the throat and mouth block the airway. In addition to never getting a restful night's sleep, patients with the condition can develop a host of problems such as high blood pressure, heart disease, heart attack and stroke.

The National Heart, Lung and Blood Institute estimates that 18 million Americans have sleep apnea.