How Does the SleepStrip™ Work?

What Is the SleepStrip™?

The SleepStrip™ is a new screening device for sleep apnea, recently approved for marketing in the United States by the Food and Drug Administration. Influ-ENT, a manufacturer and distributor of medical equipment, will market and distribute the SleepStrip™. TalkAboutSleep discussed the SleepStrip™ with Tom Page, President of Influ-ENT, to learn more about this intriguing device.

Sleep apnea is a common health problem, which can be treated but often goes undiagnosed. The standard test for sleep apnea is the polysomnogram (PSG) or sleep study, usually done in a sleep center as an overnight study. It often takes from one to three months to schedule an appointment for a sleep study.

Searching for an inexpensive, simple, quick way to screen patients for the likelihood of having sleep apnea has been a goal of recent research at the Technion Sleep Research Laboratory in Haifa, Israel. The result is the SleepStrip™.

The SleepStrip™ is a disposable tool for measuring respiration during sleep. It is a self-contained, microprocessor-driven system that contains four major elements:

• Thermosensors for sensing airflow, one for each nostril and one for oral airflow
• A built-in microprocessor to analyze the breathing patterns of the patient
• A three-volt lithium battery to power the unit
• A display to show the recorded results to the physician

These components are connected by electronic circuitry. There are two "wings" with adhesive to hold the SleepStrip™ to the upper lip, and a "bridge" containing the thermosensors.

How Will the SleepStrip™ Be Used?

According to Influ-ENT President Tom Page, any physician can prescribe or dispense the SleepStrip™ to patients whom he wants to screen for sleep apnea. While primary care physicians and sleep specialists will certainly use the device, Page envisions use by a variety of other medical specialists as well. For example, he suggests the SleepStrip™ could be used by cardiologists wanting to rule out sleep apnea in patients with ischemic heart disease, psychiatrists checking for sleep apnea in patients with depression, and sleep dentists wanting to measure the effectiveness of an oral appliance.

A typical SleepStrip™ scenario might follow this order:

• Patient complains to physician about symptoms of excessive sleepiness, fatigue or snoring
• Physician dispenses SleepStrip™, with instructions, to patient
• Patient wears the SleepStrip™ during one night of sleep
• Patient returns the SleepStrip™ to physician's office for review
• Physician reviews results and explains results to the patient

If patients show evidence of sleep apnea, they would then become candidates for a full polysomnogram, and would likely be referred to a sleep center nearby.

Page estimates the cost of the SleepStrip™ test to the patient would be approximately $100, plus office visit charges. The device is available through physicians only, as it is a medical device.

A Night with the SleepStrip™

The SleepStrip™ is easy to use, according to Page. Before going to bed, the patient would wash their face with soap and water, and dry it thoroughly, to insure good adhesion. The SleepStrip™ has two small nose sensor prongs, which should be folded forward, facing away from the patient and positioned just beneath the nostrils. The SleepStrip™ is then positioned over the upper lip, with the center bridge placed below your nose.

The patient then tests the placement of the device by checking that the sensors are measuring airflow. Looking into a mirror, the patient breathes normally, but alternates expirations between nose and mouth. At each breath, a red light on the right side of the SleepStrip™ should blink. If it doesn't, the patient readjusts the device until airflow from both nostrils and the mouth are reaching the sensors. The blinking light will go off in about 20-30 minutes.

The patient then falls asleep and the SleepStrip™ will record five hours of breathing. The sensors record a signal based on the temperature of the airflow. Inhaled air is at room temperature while exhaled air is close to body temperature. The device can measure pauses in, or reduction to, the airflow at the mouth and nose. That pattern of breathing is analyzed by the microprocessor inside. The device is capable of measuring up to 126 total apneas and hypopneas per hour.

In the morning, the red light should be blinking rapidly to indicate a successful study. If not, the test may have to be repeated. The patient returns the SleepStrip™ to the physician's office within a day or two, so that the physician can review the results and discuss them with the patient.

Research Is Ongoing

Early research results from European studies comparing the SleepStrip™ with polysomnography indicate that SleepStrip™ may effectively identify patients who suffer from sleep apnea. An abstract of these results will be presented at the annual scientific meeting of sleep professionals (APSS 2001) in Chicago in June 2001.

Research continues at a number of U.S. Sleep Centers, including Stanford, the Cleveland Clinic, Northwestern Medical Center in Chicago, the National Jewish Hospital in Denver, and St. Lukes/Roosevelt Hospital in New York. Additional studies are also underway in a number of European countries.

For more information about the SleepStrip, visit the distributor's website at www.influ-ENT.com or within the US, call 1-800-564-7077.