Apnex Medical Inc. said on Tuesday it received approval from the Food and Drug Administration to test its device on 132 patients with a common sleep disorder that causes breathing difficulty.

The implantable device, which treats obstructive sleep apnea, is used while the patient is sleeping. The device stimulates a nerve that controls the muscles in the tongue, so the patient's airways are kept open while they sleep.

The trial will take place in 15 sites in the United States and five sites abroad in Europe and Australia.

"We're very excited," said Chas McKhann, president and CEO. "This is a huge milestone for Apnex."

Apnex Medical, based in St. Paul, was founded in 2006. It has 25 employees.