Detecting Dreams Through the Finger Could Reduce Heart Attacks

More heart attacks occur during the early morning hours than at other times. Most Rapid Eye Movement (REM) or dream sleep also occurs in the early morning hours. Researchers have long suspected a connection between the two.

A novel FDA-approved device developed at the Technion-Israel Institute of Technology and at Itamar Medical Ltd., an Israeli technology company, easily and reliably identifies the onset and duration of REM sleep by tracking changes in the blood flow through the finger. This could have strong implications for prevention of heart attacks and other cardiac events by identifying physiological changes unique to this stage of sleep that may signal cardiac stress.

The device, called Watch Pat 100, will be presented at the annual meeting of the Associated Professional Sleep Societies in Chicago, June 5 to 8. The meeting -- attended by more than 6,000 sleep researchers -- will celebrate the 50th anniversary of the discovery of REM sleep.

Rather than relying on traditional methods -- rapid eye movement, EEG and EMG -- of detecting REM sleep, Watch Pat 100 reads the peripheral arterial tone (PAT), which relates to the state of dilation or constriction of the peripheral blood vessels. It shows a decrease in blood flow in the peripheral arteries during REM sleep.

"Increased resistance to blood flow in the periphery during REM sleep suggests that REM sleep can be used as a stress test for the heart," said principal investigator Professor Peretz Lavie of the Technion Faculty of Medicine, head of the Technion Sleep Laboratory, and a member of Itamar Medical's Board of Directors. "This monitor could do for heart disease what the home blood pressure monitor has done for stroke prevention."

Information about the proportion of REM sleep and its timing during the night is also very important for the assessment of sleep quality and diagnosis of sleep disturbances. Also, "people may be able to track their dreams and wake up at the right moment to remember them," Prof. Lavie added.

A significant benefit of Watch PAT 100 -- worn on the wrist and using probes that slip over two fingers -- is that it is non invasive and can be easily used at home. The signals are stored in a removable memory card in the device, which can then be downloaded to a computer for analysis. This eliminates the need to spend an expensive night in a sleep clinic hooked to multi-lead monitoring channels that register eye movements, muscle tone, and brain waves.

While the technology in the Watch PAT100 has been in use in medicine for almost a century, it could not until now be used to accurately measure PAT, nor could the signal be measured non invasively by any other means.

Two novel features of the Watch PAT 100 are the unique multi-cell construction that prevents accumulation of venous blood in the fingertip, and advanced digital signal processing algorithms to interpret the PAT signal.

In the study, conducted in Israel and Sweden, conventional laboratory sleep recordings were obtained simultaneously with PAT signals in156 patients. Then REM sleep was identified both by the conventional scoring based on eye movements, brain waves and muscle tone, and by the automatic algorithm of the Watch Pat100. The correlation between the two methods was excellent, with the automatic algorithm identifying 3.40+/-0.88 REM periods per subject as compared to a manual scoring of 3.64+/-0.98. The proportion of REM sleep was overestimated by only 4% by the automatic analysis.

Watch-PAT 100 is being marketed in the U.S. by Respironics of Murrysville, Penn., the largest sleep-medicine company in the United States, for approximately $5,400.

The Technion-Israel Institute of Technology is Israel's leading science and technology university. It commands a worldwide reputation for its pioneering work in computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. The majority of the founders and managers of Israel's high-tech companies are alumni. Based in New York City, the American Technion Society is the leading American organization supporting higher education in Israel, with more than 20,000 supporters and 17 offices around the country.