“…One of the growing modalities for portable sleep apnea screening is based on respiratory sounds/movements recorded non‐invasively over the trachea (Hafezi et al, 2020; Kalkbrenner et al, 2018; Kulkas et al, 2009; Nakano et al, 2004, 2019; Penzel & Sabil, 2017, 2018; Yadollahi et al, 2010). Previous studies estimated AHI using tracheal sounds combined with pulse oximetry (Cummiskey et al, 1982; Saha et al, 2019; Yadollahi et al, 2010), nasal pressure (Glos et al, 2019), or actigraphy (Kalkbrenner et al, 2017). Integrating another sensor such as pulse oximetry with the device attached over the trachea can increase screening accuracy; however, the integrated sensor requires synchronization with the tracheal device.…”