Skip to main content
. 2020 May 22;8(10):e14439. doi: 10.14814/phy2.14439

Figure 2.

Figure 2

A schematic of the experimental protocol for producing upper airflow obstruction in the passive state. The polysomnographic recording in one subject is shown: surface genioglossus electromyogram (EMGG), oxyhemoglobin saturation (SpO2), nasal mask pressure (P N), and pneumotach airflow (Flow). P N is abruptly reduced from an elevated holding pressure to a level that induced airflow limitation (plateau in airflow) within two or three steps, without causing an increase in EMGGG activity and any reduction of SpO2 under sustained airflow limitation. This maneuver was repeated at least three times to generate passive pressure‐flow relationships. Note that, the drop in P N from the holding pressure to lower pressure levels decreases the flow. The arrows indicate the occurrence of flow limitation as PN decreases. Ttot (the duration of inspiration) and TI (the duration of the inspiration and expiration) indicate each segment to calculate IDC in each breath