Development of a diagnostic system for sleep apnea-hypopnea syndrome using microwave radars; and dynamic analysis of heart rate variability for sleep-disordered breathing

2016 Fiscal Year Final Research Report

• Project/Area Number: 26350507
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biomedical engineering/Biomaterial science and engineering
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Kagawa Masayuki 首都大学東京, システムデザイン学部, 客員准教授 (70646702)
• Research Collaborator: TOJIMA Hirokazu ; KURITA Akira ; HASHIZUME Ayako ; YOSIDA Yuki ; SASAKI Noriyuki ; TEI Kan ; SUZUMURA Kazuki
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 睡眠時無呼吸 / マイクロ波レーダー / 非接触測定 / 心拍数変動指標 / バイタルサイン / 睡眠段階

Outline of Final Research Achievements

We developed a non-contact diagnostic system for sleep apnea-hypopnea syndrome (SAHS) that can detect apneic events without inducing stress in monitored individuals. Two radars were installed beneath the mattress to measure the vibrations of the chest and abdomen, respectively. Additionally, we proposed a technique that detects paradoxical movements by focusing on phase differences between thoracic and abdominal movements, and were able to identify three types of sleep apnea: obstructive, central, and mixed. We conducted comparative tests of radar and polysomnography on outpatients at a sleep disorder center. The radar system achieved a sensitivity of 96%, and a specificity of 100%.
We evaluated the dynamics of the heart rate variability with apneic events, LF/HF ratios began to increase 14±10 seconds after the start of obstructed sleep apnea (OSA) events.The peaks of LF/HF ratios were observed 22±12 seconds after the ends of OSA events. The average of rises in peaks was about 0.9.

Free Research Field

生体医工学