Unlike most researchers, the engineers at ImThera Medical just might consider it a compliment if someone called their product a “snooze.” The experimental device is designed to treat sleep apnea, a breathing disorder that can disrupt sleep and trigger serious complications, including an increased risk for heart disease and stroke, as well as daytime sleepiness so severe that sufferers often fall asleep at the wheel. The implant, which wraps around a nerve connected to the tongue, is now being tested in a small clinical trial in Europe.
Sleep apnea is one of the most common kinks to the breathing process. It affects as much as 4 percent of the U.S. population, and occurs when something–usually a blockage, such as the tongue–stops a person’s breathing multiple times throughout the night. The resulting oxygen deprivation and sleep loss leads to fatigue in the short-term, but it can also cause serious long-term health problems.
The gold standard for sleep apnea treatment is a CPAP (Continuous Positive Airway Pressure) machine, which keeps the airway open by forcing air through a mask and down a person’s throat. But the device is loud and uncomfortable, and roughly half of CPAP users can’t tolerate it. Alternative therapies include everything from a device that changes the relative positions of the upper and lower jaw, to actually breaking the jaw and repositioning it, to something as invasive as cutting out a portion of the patient’s soft palate to increase the airway opening.
ImThera’s device takes a different tack, one that hasn’t yet been broadly explored. The neurostimulator wraps around the tongue’s large hypoglossal nerve, and delivers electric pulses to the nerve in up to six different spots. “The goal is to open the airway by not allowing the tongue to collapse,” says Marcelo Lima, the company’s president. It does that by creating muscle tone in the muscles on the side of and beneath the tongue–muscles that flatten, stiffen, and pull the tongue forward, preventing it from relaxing and falling back to block the airway. Power comes from a rechargeable pulse generator, about the size of a Zippo lighter, which is implanted beneath the skin above the pectoral muscle in the chest, and is connected to the stimulator with a small power wire that snakes up to the throat.
Lima first tested the device using external power on two hospitalized patients in Brazil. The results were so promising that the refined device is already the center of a small clinical trial of 12 patients in Europe; a larger trial is scheduled to begin in the U.S. in mid-2010.