Sleep Easy: Researchers Develop Comfy Alternative to Diagnose Sleep Apnea

November 07, 2013 | UNIVERSITY COMMUNICATIONS

Homer Nazeran, Ph.D., left, professor of electrical and computer engineering, and doctoral candidate Jose Ayala-Moyeda are developing a low-cost, patient-friendly device to diagnose sleep apnea.
Photo by Ivan Pierre Aguirre / UTEP News Service

Spending the night at a sleep clinic can be a bit unsettling.

"A major inhibition that people have about going to sleep clinics is due to the large array and the discomfort of the sensors that are used to perform the test during sleep," said Homer Nazeran, Ph.D., professor of electrical and computer engineering at The University of Texas at El Paso.

Overnight polysomnography — or a sleep study — is the standard test sleep specialists use to diagnose sleep apnea, a disorder where one stops breathing in the middle of the night for short periods of time.

At $2,000 to $6,000 a night, the test requires patients to be hooked up to a multitude of sensors taped to the scalp, temples, chest and legs. Once the subject is ready for bed, a pair of cameras closely monitor the patient all night. Usually the test must be done more than once to arrive at an accurate diagnosis.

"They will ask you to go to sleep comfortably, but wearing all those things in an environment that's not your own — wearing something that is very uncomfortable — and being monitored by somebody else [isn't easy]," said Jose Ayala-Moyeda, a doctoral electrical engineering candidate who is doing his dissertation research with Nazeran. "It's costly, it's annoying and it's very difficult."

To reduce discomfort and the number of sensors, the team is developing an alternative to the diagnostic procedure: a patient-friendly biomedical device permitting individuals to skip the overnight sleep study in a clinic, and also avoid all the uncomfortable wires that go along with it.

The device, which includes a headband, will allow patients to sleep within the comfort of their own homes while clinically acceptable sleep data is recorded, processed and transmitted back to a clinic. Sleep specialists can then review and score the data to determine whether or not a patient has sleep apnea.

According to the Mayo Clinic, the multitude of sensors typically attached to the body in a polysomnograph record brain waves, blood oxygen level, heart rate and breathing, as well as eye and leg movements that occur during sleep.

When someone stops breathing during sleep, the brain signal changes, Nazeran said.

"The heart signal is going to vary. Eye movement changes depending on sleep stage. Muscles are going to react differently," he said. "So there are all kinds of physiological manifestations, and doctors need to look at the whole picture to make an accurate diagnosis."

The researchers are in the process of patenting their apnea detector, and say the device and software will work just as well as an overnight polysomnograph by acquiring "clinically acceptable data" solely from the forehead for sleep specialists to use in order to arrive at an accurate diagnosis. The purpose of the device is to minimize the number of sensors and make the procedure as nonintrusive and patient-friendly as possible.

An estimated 5 percent to 10 percent of Americans are affected by sleep apnea, a disorder that causes excessive snoring, disrupts the sleep cycle and leaves individuals feeling tired.

"[If you have sleep apnea] there's a high likelihood that you are going to be drowsy during the day and the implications are that you may get involved in a car accident; a lot of people involved in all kinds of accidents are sleep deprived or have sleep challenges," Nazeran said.

Long-term implications of sleep apnea are increased risk of impaired cognitive functioning and growth, diabetes, high blood pressure, stroke and heart attack — making early diagnosis and treatment critical.

However, because of high cost, sufferers often avoid the diagnostic procedure — a problem Nazeran hopes to combat with the new device.

Nazeran estimates that the sleep monitor will reduce the cost of a sleep study to one-tenth of the current price. Sleep clinics will pay an estimated $500 for the professional device and will then loan the device out to patients for home monitoring.

The researchers are also creating a non-professional version of the device that will allow users to sync the sensors with their smart mobile devices, which will enable interested individuals to monitor and manage their own sleep and gain some understanding of both the quality and quantity of their sleep.

Ayala-Moyeda, who has been testing both devices on himself at night, believes that once released, the professional device will have the larger impact.

"Of course, it can be implemented by regular users or casual users," he said. "But where we believe we can add more value is in the professional market because it will provide viable information [to sleep specialists]."

He hopes someday patients will not have to travel to hospitals or special laboratories for a polysomnograph.

"We want the majority of people to be able to get help without ever really stepping into a sleep lab," he said. "I think that we finally found a way to do it."

More than a decade of research performed by Nazeran in Australia and at The University of Texas at Arlington with Professor of Bioengineering Khosrow Behbehani, Ph.D., has contributed to these developments. Recent UTEP doctoral graduate Edson Estrada, Ph.D., also assisted with the study.

To date the project has been funded by Anita Mochen Innovation Loya Fund and UT Transform.

The team expects that clinical trials on the monitor will begin in 2014.