Sleep studies go wireless

[techno-snoreus]

Test for sleep apnea ‘unwired'
Houston researchers’ new method doesn’t stack up sensors on patients
By TODD ACKERMAN
HOUSTON CHRONICLE
Nov. 29, 2009, 8:21PM

LESS INVASIVE SLEEP STUDY
See how it works Using computer algorithms and infrared imaging, Houston researchers have created a test for sleep apnea that detects the common but potentially serious disorder without a tangle of sensors attached to the patient's body during sleep.

The creation of a University of Houston computer scientist and a University of Texas Health Science Center at Houston doctor of sleep medicine was recently studied in patients at Memorial Hermann Hospital and found to be just as accurate at diagnosing sleep apnea as the traditional sensor-laden method, known as polysomnography.

“This could mark a major change in the way we diagnose sleep apnea,” says Dr. Jayasimha Murthy of UT-Houston's division of pulmonary critical care sleep medicine, one of the investigators. “All the sensors used in traditional diagnosis can disturb sleep and contribute to patient anxiety. With this, we hope to ‘unwire' subjects during sleep studies.”

The new test, which the researchers describe in the November issue of the journal Sleep, is the first of its kind to diagnose sleep apnea using “non-contact technology.” A thermal infrared camera about 8 feet away collects information based on airflow throughout the sleeping patient's nostrils.

Sleep apnea, which is characterized by temporary breath interruptions during sleep, affects 24 percent of men and 9 percent of women. It is associated with a number of health problems, including hypertension, heart disease and stroke.

It occurs when the muscles in the throat, soft palate and tongue relax during sleep, sagging and narrowing the airway, which blocks the windpipe and cuts off oxygen to the lungs. In a cycle typically repeated hundreds of time a night, the sleeper rouses from slumber to gasp for air, then falls back asleep. The awakening is usually so brief the sleeper doesn't remember it.

The only way to diagnose the condition is with a sleep study, during which the patient must sleep wearing more than 20 sensors, usually hooked up to the head, nose, legs, arms and chest. Ioannis Pavlidis, a UH computer science professor and co-developer of the test, says it's not exactly “like paying a short visit to the doctor in the morning and walking away with a prescription.”

The new test retains some of the sensors, but doesn't require any in the most obtrusive area, the nose. In the test, the infrared imaging captures patients' unique thermal signature, a product of the cooler atmospheric air taken into the nostrils and the warmer air exhaled. Computational algorithms process the readings.

The test also provides a wealth of information not previously accessible, says Pavlidis.

“In contrast to the traditional one-dimensional methods, this new method is multi-dimensional,” says Pavlidis. “We can see how airflow is distributed locally throughout the extent of the nostril. We get multiple values, rather than a single one, for each nostril at every point in time, which makes a lot of difference when it comes to appreciating subtle pathology.”

Pavlidis and Murthy studied 27 subjects, 13 with a history of sleep apnea and 14 without, during two hours of sleep at Memorial Hermann's sleep disorders center. The study showed a high degree of agreement in data returned from traditional polysomno- graphy and the new test.

Pavlidis and Murthy said their next study will look at subjects during a full night of sleep.

Dr. Shyamsunder Subramanian, a Baylor College of Medicine professor of medicine and sleep specialist, called the test “a good breakthrough, preliminary but very exciting.” But he said it's unclear whether it will eventually replace polysomnography except in severe cases “because it doesn't provide some of the information polysomnography does about sleep airflow's subtle effect on brain activity.”

todd.ackerman@chron.com

http://www.chron.com/disp/story.mpl/met ... 44538.html

[Slinky]

AND ... I don't see any mention of it being able to detect any of the some 80 other sleep disorders that a PSG can.

[secret agent girl]

.

[Slinky]

I haven't got the slightest idea. I've just seen a couple of different RPSGTs mention that number. I "think" that Dr Steven Y Park might have mentioned that number as well. You could try checking his website. A google search on his name should bring his web site up.

[macmermaid]

I was curious so I googled it. From Wikipedia (not scientific, obviously):

The most common sleep disorders include:

* Primary insomnia: Chronic difficulty in falling asleep and/or maintaining sleep when no other cause is found for these symptoms.
* Bruxism: Involuntarily grinding or clenching of the teeth while sleeping
* Delayed sleep phase syndrome (DSPS): inability to awaken and fall asleep at socially acceptable times but no problem with sleep maintenance, a disorder of circadian rhythms. Other such disorders are advanced sleep phase syndrome (ASPS) and Non-24-hour sleep-wake syndrome (Non-24), both much less common than DSPS.
* Hypopnea syndrome: Abnormally shallow breathing or slow respiratory rate while sleeping
* Narcolepsy: Excessive daytime sleepiness (EDS) often culminating in falling asleep spontaneously but unwillingly at inappropriate times.
* Cataplexy, a sudden weakness in the motor muscles that can result in collapse to the floor.
* Night terror, Pavor nocturnus, sleep terror disorder: abrupt awakening from sleep with behavior consistent with terror
* Parasomnias: Disruptive sleep-related events involving inappropriate actions during sleep stages - sleep walking and night-terrors are examples.
* Periodic limb movement disorder (PLMD): Sudden involuntary movement of arms and/or legs during sleep, for example kicking the legs. Also known as nocturnal myoclonus. See also Hypnic jerk, which is not a disorder.
* Rapid eye movement behavior disorder (RBD): Acting out violent or dramatic dreams while in REM sleep
* Restless legs syndrome (RLS): An irresistible urge to move legs. RLS sufferers often also have PLMD.
* Situational circadian rhythm sleep disorders: shift work sleep disorder (SWSD) and jet lag
* Obstructive sleep apnea: Obstruction of the airway during sleep, causing lack of sufficient deep sleep; often accompanied by snoring.

Other forms of sleep apnea are less common.
* Sleep paralysis is characterized by temporary paralysis of the body shortly before or after sleep. Sleep paralysis may be accompanied by visual, auditory or tactile hallucinations. Not a disorder unless severe. Often seen as part of Narcolepsy.
* Sleepwalking or somnambulism: Engaging in activities that are normally associated with wakefulness (such as eating or dressing), which may include walking, without the conscious knowledge of the subject.
* Nocturia: A frequent need to get up and go to the bathroom to urinate at night. It differs from Enuresis, or bed-wetting, in which the person does not arouse from sleep, but the bladder nevertheless empties.[1]
* Somniphobia, a dread of sleep

[edit]

[secret agent girl]

.

[dsm]

I am waiting for the iPhone Apple App Store to list a program to capture the data wirelessly off my future cpap & to display the resuling charts on the iPhone or on an attached web site - can do this with my memos today

DSM

(have become a real fan of this revolutionary personal communicator/computer. Am so impressed by what Apple have done here that I am working on running classes at work (IT shop) on how to develop iPhone applications using the built-in Safari browser as the GUI and a back-end website environment called RubyOnRails (with MySql) to be the application engine. Sooner or later someone will develop cpap related apps for the iPhone or even the new proposed 'Apple Slate' (iBook) device rumored for announce in Jan 2010).

Once again we are in interesting times when it comes to social networking computing.

#2 Slate rumours ...
http://www.gadgetvenue.com/apple-slate-coming-10264913/

#3 Actually, the slate may be 'slated' for publishing but, there are some of us followers who believe Steve Jobs has a much broader market in mind in that the iPhone is finding its way into business & our company is a typical example of a country wide org starting to look at it as an alternate to the PDAs & Tablets we have used in various projects the past (mostly they have failed). Assuming the 'Slate' has the same finger interface that the iPhone has, then we can see the device fitting in to a wide variety of corporate uses where PDAs/Tablets just haven't been up to scratch in the past. In the developer community, iPhone development is a hot topic & appears to be caturing the hearts & minds of the current generation of youngsters emerging from colleges & universities & looking for where the action is. Google Chrome & Android also appear to be following in Apples tracks but Apple are clearly way out in front at the moment.