Researchers describe new cost-effective method to assess sleep

August 29, 2005

BOSTON - Using information hidden in the beat-to-beat changes of the heart's electrical signals, researchers at Beth Israel Deaconess Medical Center (BIDMC) have developed an inexpensive method to assess the stability and quality of sleep, which could be used to help understand the mechanisms of sleep control and diagnose sleep disorders, as well as to test the efficacy of sleep aids and other medications.

Known as a "sleep spectrogram," the novel graph is based on data obtained solely from a simple electrocardiogram (ECG). The spectrogram is described in a study in the Sept. 1 issue of the medical journal Sleep, which currently appears on-line.

"This new ECG-based approach is important because it promises to provide an affordable and readily achievable way to monitor sleep stability in a wide range of conditions, including sleep apnea, depression, fibromyalgia, heart failure and stress," explains cardiologist Ary Goldberger, MD, Director of the Margret & H.A. Rey Institute for Nonlinear Dynamics in Medicine and the study's senior author.

The new study, led by sleep researcher Robert Thomas, MD, of BIDMC's Division of Pulmonary, Critical Care and Sleep Medicine, identified two distinct types of behavior exhibited throughout the course of a person's sleep, the first being stable and restful, the second being unstable and aroused. The results show that conventional approaches to categorize non-REM (non-rapid-eye-movement) sleep into grades of depth do not capture this potentially important dimension.

"Among healthy adults, physiological behaviors will show relatively abrupt shifts - a occurring over minutes - between both stable and unstable sleep, but the stable stage clearly dominates," explains Goldberger, who is also a Professor of Medicine at Harvard Medical School. "But," he adds, "in a variety of disease states, the spectrogram shows that an unstable sleep pattern is predominant, and among patients with severe cases of sleep apnea, virtually all of the patient's non-REM sleep is unstable."

The creation of the spectrogram could serve as an important complement to traditional sleep staging, which shows cycles of rapid eye movement (REM) and non-REM sleep and is obtained through polysomnography, a series of measurements that require the use an electroencephalogram (EEG) to record patients' brain waves.

"Spectrograms can uncover information that is not provided by traditional sleep scoring," notes Thomas. "Polysomnograms are both expensive and time-consuming. The spectrogram, therefore, could provide a new way of looking at sleep and offer doctors an alternative to the REM/non-REM sleep scoring system.

Furthermore, we have more recent data showing that the patterns in humans and rodents are remarkably similar, and suggesting that what we may be observing is a fundamental and conserved sleep mechanism."

In addition to Goldberger and Thomas, study coauthors include BIDMC engineer Joseph Mietus and C.K. Peng, PhD, of BIDMC's Cardiovascular Division.
This study was supported by the National Institutes of Health, the G. Harold and Leila Y. Mathers Foundation and the James S. McDonnell Foundation.

Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School, and ranks third in National Institutes of Health funding among independent hospitals nationwide. BIDMC is clinically affiliated with the Joslin Diabetes Center and is a research partner of Dana-Farber/Harvard Cancer Center.

Please note: Slide depictions of the sleep spectrogram are available upon request.

Beth Israel Deaconess Medical Center

Related Sleep Apnea Articles from Brightsurf:

Sleep apnea may be risk factor for COVID-19
The question of sleep apnea as the risk factor for COVID-19 arose in a study conducted by the Turku University Hospital and the University of Turku on patients of the first wave of the pandemic.

Untreated sleep apnea is associated with flu hospitalization
As we approach flu season, adults with obstructive sleep apnea may want to take extra precautions.

Losing tongue fat improves sleep apnea
Using magnetic resonance imaging (MRI) to measure the effect of weight loss on the upper airway in obese patients, researchers found that reducing tongue fat is a primary factor in lessening the severity of OSA.

More cancer cases among women with sleep apnea
Women with severe sleep apnea appear to be at an elevated risk of getting cancer, a study shows.

New evidence on the association of shortened sleep time and obstructive sleep apnea with sleepiness and cardiometabolic risk factors
A new study in the journal CHEST® may change the way we think about sleep disorders.

Synthetic cannabis-like drug reduces sleep apnea
A synthetic cannabis-like drug in a pill reduced apnea and daytime sleepiness in the first large multi-site study of a drug for apnea.

Inflammation may precede sleep apnea, could be treatment target
Inflammation is traditionally thought of as a symptom of sleep apnea, but it might actually precede the disorder, potentially opening the door for new ways to treat and predict sleep apnea, according to researchers.

Concerns that sleep apnea could impact healthspan
The number of people with obstructive sleep apnea has steadily increased over the past two decades.

Sleep apnea and insomnia combination linked with depression
A new study found that men with sleep apnea and insomnia have a higher prevalence and severity of depressive symptoms than men with sleep apnea or insomnia alone.

Anti-nausea drug could help treat sleep apnea
An old pharmaceutical product may be a new treatment for obstructive sleep apnea, according to new research presented today by University of Illinois at Chicago and Northwestern University scientists at the SLEEP 2017 annual meeting in Boston.

Read More: Sleep Apnea News and Sleep Apnea Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to