Apnea-hypopnea duration may be a better choice rather than apnea-hypopnea index for forecasting complications in OSAS.

Objective: Mean apnea-hypopnea duration (AHD) is the mean duration of apnea-hypopneas experienced during sleep and was found as an indicator of blood oxygenation. The aim of this study was to compare and define the differences in clinical, demographic and polysomnographic characteristics of obstructive sleep apnea (OSA) patients in long and short AHD groups and investigate the relationship between apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and sleepiness.

Methods: The cross-sectional analysis included 511 OSA patients who were >18 years and followed up between June 2019 and December 2019 in the Sleep Center of university hospital.

Tactile Perception of Virtual Edges and Gratings Displayed by Friction Modulation via Ultrasonic Actuation.

Tactile discrimination and roughness perception of real textures are extensively studied and underlying perceptual mechanisms are relatively well-established. However, tactile perception of virtual textures rendered by friction modulation techniques on touch surfaces has not been investigated in detail yet. In this article, we investigated our ability to discriminate two consecutive step changes in friction (called edges), followed by discrimination and roughness perception of multiple edges (called periodic gratings).

Psychophysical Evaluation of Change in Friction on an Ultrasonically-Actuated Touchscreen.

To render tactile cues on a touchscreen by friction modulation, it is important to understand how humans perceive a change in friction. In this study, we investigate the relations between perceived change in friction on an ultrasonically actuated touchscreen and parameters involved in contact between finger and its surface. We first estimate the perceptual thresholds to detect rising and falling friction while a finger is sliding on the touch surface.