Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New way to analyze sleep disorders

17.04.2009
Described in the latest issue of the journal Chaos

Sleep is such an essential part of human existence that we spend about a third of our lives doing it -- some more successfully than others. Sleep disorders afflict some 50-70 million people in the United States and are a major cause of disease and injury.

People who suffer from disturbed sleep have an increased risk of heart attack, stroke, hypertension, obesity, depression, and accidents. Nearly a fifth of all serious car crashes, in fact, are linked to sleeplessness.

Diagnosing sleep disorders is not necessarily easy. In standard "sleep studies," people spend one or more nights at hospitals or other inpatient centers, sleeping while sensors and electrodes attached to the head and torso record breathing, brain waves, heart rate, and other vital signs.

Now, a group of scientists in Israel and Germany has discovered a simple new way to monitor sleep and potentially diagnose sleep disorders just by recording someone's heart rate. Their method relies on using a mathematical technique to analyze these recordings and tease out information related to the synchronization between heartbeat and breathing, which might be a measure of fitness of the cardio-respiratory system.

Their work may one day help clinicians more easily diagnose sleep disorders and determine optimal treatments for people with congestive heart failure. Athletes might also be able analyze their own recordings to optimize workouts.

Conducted by researchers at Technische Universität Ilmenau in Germany, Bar-Ilan University in Ramat Gan, Israel, Martin-Luther-Universität Halle-Wittenberg in Germany, and Schlafmedizinisches Zentrum der Charité Berlin, the work appears in a special focus issue of the journal Chaos, which is published by the American Institute of Physics (AIP). The special issue is focused on nonlinear dynamics in cognitive and neural systems. It asks how chaos affects certain brain areas and presents interdisciplinary approaches to various problems in neuroscience -- including sleep disorders.

Monitoring the heartbeat provides information about breathing because the two physiological processes are weakly coupled. During inhalation, the heart beats faster. During exhalation, the heart slows down. These effects are seen during sleep as well. Moreover, the heart rate and breathing rate also change across certain stages of sleep. They are faster and fluctuate more during rapid eye movement (REM) sleep than they do during deep sleep, for instance.

In their new study, the Israeli and German scientists showed that the synchronization between the heartbeat and breathing pattern is significantly enhanced during certain stages of sleep. By mathematically analyzing someone's heart rate throughout the night, they could gain information on that person's breathing and sleep stage.

They looked at data from the European project SIESTA, which keeps a database of sleep data recorded in seven countries from 295 people -- about half of whom have sleep disorders. Subjects of this study spent two nights in sleep laboratories, slumbering while electrodes connected to their heads and torsos monitored things like brain and muscle activity, heart rate, and eye movement. This collection of physiological data is what normally enables doctors to reconstruct the phases of sleep and diagnose sleep disorders.

The Israeli and German scientists analyzed just the heart data for the 150 people in the SIESTA study who have no known sleep disorders. They then used the heartbeats to reconstruct the breathing patterns, and they showed that these reconstructions accurately reflect the actual recorded breathing data collected in sleep labs. Moreover, looking at the synchronization between heartbeat and breathing, the group could show that there is a significant relationship between sleep stages and cardio-respiratory synchronization patterns, i.e., heartbeat and breathing mostly synchronize during non-REM sleep (light and deep sleep), and cardio-respiratory synchronization is almost absent during REM sleep.

Next they plan to extend their study to people with sleep disorders to determine whether their technique can accurately diagnose these disorders. Analyzing the heartbeat using their technique may also reveal information about cardiorespiratory capacity, which may lead to diagnostic markers of cardiac diseases and ways to determine optimal treatments for people with congestive heart failure. Monitoring cardiorespiratory capacity may also help atheletes optimize workout routines.

Jason Bardi | EurekAlert!
Further information:
http://www.aip.org

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Nonstop Tranport of Cargo in Nanomachines

20.11.2018 | Life Sciences

Researchers find social cultures in chimpanzees

20.11.2018 | Life Sciences

When AI and optoelectronics meet: Researchers take control of light properties

20.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>