Fascinating: an alternative to the CPAP mask that is an effective (but bothersome) treatment for apnea. Apnea occurs because the body totally relaxes muscles during deep sleep, which lets the airway collapse under negative pressure of inspiration. So this neurostimulator regularly and selectively activates the muscles surrounding the airway, stiffening them during inspiration so that the airway doesn’t collapse.
For Sleep Apnea Patients, a Possible Alternative to Masks – NYTimes.com.