Wednesday, November 4, 2009

Thermal Infrared Imaging to Detect Sleep Apnea

The Nov. 1 issue of the journal Sleep contains the first reported study of “thermal infrared imaging” to monitor airflow during an overnight sleep study. Can this technology be used to detect obstructive sleep apnea?

Typically, contact sensors are placed around your nose and mouth to measure airflow during a sleep study. The authors report that these sensors and wires may cause discomfort during sleep.

The advantage of thermal infrared imaging is that it uses “non-contact” sensing to detect airflow abnormalities. It is unobtrusive and doesn’t touch your body while you sleep.

The automatic thermal moni­toring system (ATHEMOS) uses an infrared camera to record your sleep from a distance. It acquires ther­mal information as heat radiates from your nostrils.

The thermal signature of the nostrils varies. It is cooler as you inhale, and warmer as you exhale air from the lungs. This thermal signal provides information about your breathing.

But is it effective? The small pilot study found a high degree of agreement between thermal infrared imaging and conventional airflow sensors.

But the system wasn’t tested during a full night of sleep. The average recording time was less than two hours per person.

This is because the method produces massive data sets. Recording a full night of sleep would require an investment in upgraded computer systems for data management and storage.

Thermal infrared imaging also involves another major expense: the camera. The authors note that an entry-level, thermal camera can cost about $60,000 at this time.

The benefit of this system is that it doesn’t require the sterilization or replacement of sensors; this minimizes the operating costs over time.

The automatic thermal monitoring system is a unique prototype that is still in development. The authors are optimistic that it could be useful in the detection of obstructive sleep apnea. But much more testing is needed to validate its effectiveness.

1 comment:

Mark D. A. Rosen said...

I am glad that what I proposed 10 years ago is finally becoming a reality!

The presentation that was attached to the e-mail below can be found on my website.

----- Original Message -----
From: Mark Rosen
To: Ioannis Pavlidis
Sent: Monday, August 15, 2005 8:45 AM
Subject: IR Imaging and Sleep Studies

Dear Prof. Pavlidis,

For almost 6 years, I have been trying to prod the people in the sleep research community to investigate the potential of IR imaging as a “perfect” non-contact monitoring technology for sleep studies. I have attached the presentation I put together which I presented to the Children’s Sleep Lab at Yale in 1999 and distributed to the sleep research community in 2002.* You and your colleagues have done some outstanding work, actually solving what I consider the toughest challenge in being able to monitor heart rate and breathing. I would greatly appreciate it if you could keep me informed of your progress (preprints or Acrobat pdf files).

Wishing you the very best in your research efforts.

With my very best regards,

Mark Rosen, Ph.D.

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