The primary endpoints for this study are that the AL validation will 1) achieve a sensitivity of greater than 80% for AHI values greater than or equal to 15, and 2) demonstrate a correlation coefficient of r=0.75 indicating strong correlation between the AHI of diagnostic PSG and AL.

All subjects with suspected Sleep Disordered Breathing (SDB) scheduled for diagnostic polysomnography (PSG) will be invited to participate in the study to be tested to determine if they have Sleep Disordered Breathing (SDB), using the ApneaLink (AL) Sleep Screener. Subjects initially will be tested for SDB in the home environment. Following an AL home test, subjects will undergo a simultaneous, attended diagnostic polysomnography (PSG) sleep study and ApneaLink test for the purpose of confirming and comparing the results between diagnostic PSG and the AL device.

Inclusion Criteria:

• Adult subjects ( greater than 18 years of age) of either gender or any race
• Suspected sleep disordered breathing
• Untreated sleep disordered breathing
• Willingness to use AL at home within 2 days of receipt and instruction on the AL
• Willingness to use AL at home and undergo PSG within 2 to 4 weeks of completing the at home AL test

Exclusion Criteria:

• Any subject requiring home oxygen therapy
• Any subject currently receiving positive airway pressure therapy

Pts. with suspected OSA.

There is no plan to share IPD.