Fibromyalgia, a chronic condition also involves fatigue and multiple tender points that cause pain after slight pressure.

In collaboration with the University of Michigan's sleep laboratory, a team led by Joseph W. Burns of the Michigan Tech Research Institute, used remote sensors, signal processing and computer software to correlate measures of sleep fragmentation with levels of pain reported by fibromyalgia patients.

"In this case, our analyses of sleep stage dynamics suggest potential clinical relevance," Burns said in a statement.

The researchers have developed an automated technique for assessing the severity of sleep-disordered breathing, using just two signals -- brain waves and respiration -- instead of the dozen or more signals typically needed for standard visual scoring of a sleep study.

Burns, Ronald Chervin of the University of Michigan's Michael S. Aldrich Sleep Disorders Laboratory and Leslie Crofford of the Center for the Advancement of Women's Health at the University of Kentucky reported the findings in the journal Sleep Medicine.