Validation of a High-resolution Oximeter Using a Cloud-based Algorithm to Diagnose Obstructive Sleep Apnea

Obstructive Sleep Apnea (OSA) is extremely common has prompted the popularization of home sleep test (HST). HST record a limited number of respiratory signals, provide a more comfortable testing option to the patient at a lower cost. HST has a performance as good as PSG among patients with suspected OSA and no significant co-morbidities.

Our study was designed to investigate the performance of a simple solution that consists of a high-resolution wireless oximeter with a built-in accelerometer linked to a smartphone application and automated cloud algorithm for detection of oxygen desaturation, described herein as Overnight Digital Monitoring (ODM) (BilogixTM). We will compare the results of ODM with HST performed by ApneaLink Air by Resmed®.

We have already compared ODM to PSG with excellent results in a prior study and intend to see the results in uncontrolled environment (home) .

Population: Men and women from the São Paulo Department of Health, who are awaiting examination for diagnosis of OSAS.We intend to compare the ODM with the HST. Patients with indication for CPAP titration will be excluded. The participants will wear a wireless oximeter (Oxistar, Biologix Sistemas Ltda., Brazil) with a built-in accelerometer on a finger of the same hand as the HST oximeter and we will compare both methods for diagnosing OSA.

All HST studies will be scored by 2 independent certified technicians blinded to the ODM results. Hypopnea will be defined as a peak signal excursion drop by ≥ 30% of pre-event baseline nasal pressure signal lasting ≥ 10 sec. Hypopneas will be scored according the acceptable AASM criteria for hypopnea (≥ 4% reduction in SpO2). Mild, moderate and severe OSA will be defined according to the current standards (5 ≤ AHI <15; 15 ≤ AHI <30 and AHI ≥30 events/h, respectively).ODI results from ODM will be expressed as the number of desaturations per recording time and will be automatically analyzed at the cloud. In order to compare with TST-AHI4%, ODM will be matched using 4% desaturation criteria (ODM-ODI4%, respectively).