Rehabilitation outcome in patients with obstructive sleep apnea syndrome using wearable inertial sensor for gait analysis

Obstructive Sleep Apnea (OSA) is a common sleep-related breathing disorder characterized by discontinuous reduction or cessation of airflow. The OSA syndrome reduces the maximal aerobic capacity, increasing cardiovascular risk and functional limitation. The 6-Minutes Walking Test (6MWT) is used in clinical environment to assess the maximal exercise capacity in OSA patients, and also to monitor other physiological parameters during physical effort. In this study thirteen patients suffering with OSA syndrome performed an instrumented 6MWT using an automatic system for movement analysis (BTS G-Walk) and underwent a comprehensive clinical assessment by means of a set of selected clinical scales, at baseline (T0) and after a period of rehabilitation (T1). The paired t-test was used to assess whether statistically significant variation occurs in the analyzed parameters due to the treatment received. The 6MWT distance, all the clinical scales (Short Physical Performance Battery, Modified Medical Research Council Dyspnea Scale, Barthel Index for Dyspnea and EuroQol Visual Analogue Scale) and the Borg index for Dyspnea and Fatigue assessed during 6MWT show significant changes, proving to be good indices to assess rehabilitation outcome. The oxygen desaturation and the variation of heart rate registered during the walking test do not change significantly at T1. Results confirm the importance of respiratory rehabilitation which improves physical endurance and patient's self-assessment of his/her own health and quality of life.