The Studies of Respiratory Regulation and Sleep Apnea on Autonomic Nervous System for Improving Sleep Quality

• Main Authors: Yung-Ming Chung, 鐘永銘
• Other Authors: Ming-Chen Wang
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/a8nue2

博士 === 中原大學 === 生物醫學工程研究所 === 107 === Sleep apnea causes sleeping disturbance and also influences the quality of sleep obviously. I hypothesized that sleep apnea affects the balance of autonomic nervous system (ANS), which activates sympathetic nervous system (SNS) and suppress parasympathetic nervous system (PNS) during sleep. This causes body cannot get appropriate rest and repair the tissue through sleep. Since the PNS restores and conserves body and in response to stimulations. hence, voluntary control of respiratory rhythm, known as respiratory regulation, is considered a type of external stimulation to the body. Therefore, I also hypothesized that PNS can be activated by respiratory regulation for improving sleep quality. Upon the hypotheses, this study used heart rate variability (HRV) to analyze the data of sleep apnea patients, the results indicated that the severe group (AHI ≥ 30) has higher sympathetic nervous system (SNS) activity and lower parasympathetic nervous system (PNS) activity in nonrapid eye movement (NREM). Furthermore, apnea events occurring in NREM activated SNS and suppressed PNS activity. Owing to sleep apnea is associated with an imbalance of ANS activity. Therefore, twenty-five subjects were examined simultaneously using polysomnography (PSG) and an HRV-based sleep staging method during sleep. The method had an accuracy of 81.52% in identifying NREM when compared with the accuracy of PSG results. Furthermore, the accuracy of identifying NREM sleep in healthy (AHI < 5) and severe sleep apnea (AHI ≥ 30) groups was 92.49% and 86.82%, respectively, which was significantly greater than in the other groups. The findings proved that sleep apnea affects the balance of ANS, which activates SNS and suppress PNS during sleep. Hence, if sleep apnea severity can be early detected, then the sleep quality will be significantly improved. We further developed a software using Back-Propagation Network as the classifier to identify sleep apnea. The results show that its accuracy is 70.7%. In addition to identifying sleep quality, how to improve sleep quality is also important, therefore, we studied the efficacy of respiratory regulation on PNS using HRV. The results highlighted that sympathetic nervous system and PNS are easily activated and inhibited, respectively, during Mode 2 (inhalation 3 s, exhalation 6 s) breathing mode. This allowing PNS to quickly become predominant, causing the body to relax during the following resting session (HFnu, 0.32, p < 0.05). These results suggest that Mode 2 can be used as a breathing model for long-term improvements in PNS function. In the future, those works can be further integrated as a sleep bio-feedback system with the respiratory regulation method for improving sleep quality.