Introduction. aim: Obstructive Sleep Apnea (OSA) is defined as the collapse of the upper respiratory tract. complete or partial. leading to hypopnea to apnea. https://www.jmannino.com/quick-offer-Viqua-F4-50-Plus-Monitored-UV-System-Powered-by-UVMax-15-gpm-230-Volt-on-sale/