A multicentric validation study of a novel home sleep apnea test based on peripheral arterial tonometry

Abstract

Study objectives This paper reports on the multi-centric validation of a novel FDA cleared home sleep apnea test based on peripheral arterial tonometry (PAT HSAT). Methods 167 participants suspected of having obstructive sleep apnea (OSA) were included in a multi-centric cohort. All patients underwent simultaneous polysomnography (PSG) and PAT HSAT, and all PSG data were independently double scored using both the recommended 1A rule for hypopnea, requiring a 3% desaturation or arousal (3% Rule), and the acceptable 1B rule for hypopnea, requiring a 4% desaturation (4% Rule). The double-scoring of PSG enabled a comparison of the agreement between PAT HSAT and PSG to the inter-rater agreement of PSG. Clinical endpoint parameters were selected to evaluate the device’s ability to determine the OSA severity category. Finally, a correction for near-boundary AHI values was proposed to adequately handle the inter-rater variability of the PSG benchmark. Results For both the 3% and the 4% Rule, most endpoint parameters showed a close agreement with PSG. The 4-way OSA severity categorization accuracy of PAT HSAT was strong, but nevertheless lower than the inter-rater agreement of PSG (70% vs 77% for the 3% Rule and 78% vs 81% for the 4% Rule). Conclusions This paper reported on a multitude of robust endpoint parameters, in particular OSA severity categorization accuracies, while also benchmarking clinical performances against double-scored PSG. This study demonstrated strong agreement of PAT HSAT with PSG. The results of this study also suggest that different brands of PAT HSAT may have distinct clinical performance characteristics.

Central Sleep Apnea Detection by Means of Finger Photoplethysmography

“…PAT HSAT makes use of a fingertip mounted PPG probe [19] , [20] . PPG operates on simple optical technology to detect blood volume changes in the tissue’s microvascular bed [23] , [24] .…”

“…PPG operates on simple optical technology to detect blood volume changes in the tissue’s microvascular bed [23] , [24] . PPG measurements are used to derive the arterial blood oxygen saturation (SpO 2 ), pulse rate (PR), and changes in peripheral arterial tone, which are then used to detect respiratory events [19] , [20] . Peripheral arterial tone refers to the tone of the peripheral arterial smooth muscle tissue.…”

“…Near the end of a respiratory event, the sympathetic nervous system activity spikes to arouse the patient, resulting in resumption of ventilation, a surge in pulse rate and a release of norepinephrine in the blood stream. Consequently, norepinephrine binds to alpha-adrenergic receptors innervating the arterial smooth muscle tissue in the finger, causing sudden vasoconstrictions, and corresponding increases in PAT, picked up by the PPG sensor [19] , [20] .…”

“…Respiratory event extraction from raw PPG The PAT HSAT uses PPG and PPG derived signals such as PR and SpO2 to detect respiratory events. This method has been previously validated by Massie et al and Van Pee et al [19], [20]. At this point, no distinction has been made between obstructive and central events.…”

“…PAT HSAT allows for minimally invasive multi-night testing and is available in a fully disposable format [17] , [18] . This study makes use of the FDA cleared NightOwl PAT HSAT (Study Device), first described by Massie et al [19] , [20] . It comprises a finger probe of the size of a fingertip and a cloud-based analysis software ( Fig.…”