Apnex Hypoglossal Nerve Stimulation for OSA

We recently reported on an implantable nerve stimulator from Inspire Medical Systems that aims to help people with obstructive sleep apnea (OSA). During sleep the system monitors one’s breathing and stimulates the hypoglossal nerve to help open muscles in the upper airway, to keep it open. We now learn that Apnex Medical out of St. Paul, Minnesota is conducting a clinical trial of a competing product, the Apnex Hypoglossal Nerve Stimulation (HGNS™) System.
Here’s how the Apnex system works:

Implanted Components
The Neurostimulator is implanted in a subcutaneous pocket inferior to the clavicle over the pectoralis fascia. A nerve cuff electrode on the distal end of the Stimulation Lead is implanted on a branch of the hypoglossal nerve (HGN) in the submandibular region. The proximal end of the Stimulation Lead is tunneled under the skin to the Neurostimulator. The Respiration Sensing Leads are tunneled under the skin from the Neurostimulator to the costal margins.
External Components
The Programmer System and Therapy Controller are wirelessly linked to the Neurostimulator. The Programmer System includes the following components: computer; programmer interface; and programmer head. The programmer system is used by the physician to control and program the Neurostimulator during surgery and therapy titration. The Therapy Controller is used by the patient to control limited aspects of therapy delivery, to meet their unique sleep needs.
The Apnex HGNS System is intended to work by restoring neuromuscular activity to the genioglossus muscle by stimulating the hypoglossal nerve synchronous with inspiration to mitigate upper airway collapse during sleep. This is similar to how the body’s natural neuromuscular physiology functions in people without OSA. Stimulation is generated by the Neurostimulator, synchronized with inspiration as measured by the Respiration Sensing Leads using bio-impedance, and delivered to the hypoglossal nerve by the Stimulation Lead.

Technology page: Apnex HGNS Therapy
Flashback: Inspire II Implantable Nerve Stimulator for Obstructive Sleep Apnea
(hat tip: Star Tribune)