SomnoStay

A Novel Oral Appliance for Obstructive Sleep Apnea

University of California, San Diego

Mechanical and Aerospace Engineering

MAE 156B: Senior Design Project

Project Background:

Obstructive Sleep Apnea (OSA) is a common sleep disorder where the upper airway becomes blocked during sleep. This is often caused by the tongue falling back and obstructing airflow. Under the instruction of Dr. Jeremy Orr, Board Certified pulmonary and critical care physician, our team developed a medical device to prevent tongue obstruction for patients with obstructive sleep apnea.

Tongue Obstruction

For some, the tongue falls into the back of the throat during sleep. This obstructs the airway, leading to oxygen deprivation to the brain.

Proposed Solution

The proposed solution, where a retainer-like piece suctions the tongue to the roof of the mouth.

Design Solution

The medical device, SomnoStay, applies light negative pressure directly onto the surface of the tongue to keep the tongue located at the roof of the mouth, preventing tongue obstruction in the airway. The retainer has holes on the bottom, which results in suction being applied to the tongue. This holds the tongue up against the retainer and out of the patient’s throat.

The device uses a pressure sensor to monitor suction pressure levels and controls a small air pump through an Arduino UNO and MOSFET. The suction is applied by a motor pump through a retainer which is fixed to the roof of the patient’s mouth. A feedback loop between the pressure sensor and motor ensures safe pressure limits are maintained while also applying enough suction to hold the human tongue. The system is adjustable, compact, and designed for minimal noise during operation to reduce sleep disruption. Initial testing confirms motor functionality and pressure sensor integration. Future work will focus on suction profiles and clinical safety.

For an in depth analysis of each component, please see our Final Design Page.

Prototype Performance

The motor controller was switched on for one minute of continual operation. The target pressure was set at 7355 Pa. This target pressure corresponds to a cumulative force of 1.34 N. This threshold was used because it is greater than the weight of the tongue, at 1.0 N, but limits pressure applied to be less than 11964 Pa, which was the highest negative pressure that a competing product (iNAP) was cleared to operated by the FDA without risking damage to the mouth (Somnics Health). Further details are discussed in the Final Report.