Physiological effects of low-level inhalation exposure to carbon dioxide in workplace environments

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H04282
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 63040:Environmental impact assessment-related
• Research Institution: Osaka University
• Principal Investigator: Kiyono Ken 大阪大学, 基礎工学研究科, 教授 (40434071)
• Co-Investigator(Kenkyū-buntansha): 金子 美樹 大阪大学, 基礎工学研究科, 助教 (10795735)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 環境影響評価 / 生体信号解析 / 生体機能評価

Outline of Final Research Achievements

We evaluated effects of inhalation of carbon dioxide with 2500 ppm or less on cognitive and physiological functions. In our study, an experimental chamber automatically controlling the upper limit of the carbon dioxide concentration was developed, and cognitive function evaluation tests and biosignal measurement such as heart rate, heart rate variability, and respiratory rate were carried out using the experimental chamber. To analyze the biosignal time series, we developed methods such as long-term cross-correlation analysis of cardiopulmonary interactions and direction-dependent fractal analysis of two-dimensional time series. In our experiments in which the carbon dioxide concentration level was set to 1500 ppm and 2500 ppm, changes in heart rate variability characteristics were observed depending on the concentration level. In our study, there were large individual differences in the physiological effects of carbon dioxide concentration.

Free Research Field

生体情報学

Academic Significance and Societal Importance of the Research Achievements

室内の二酸化炭素濃度が上昇すると，次第に眠気，倦怠感，頭痛などの症状が現れることしられており，本研究成果は，二酸化炭素濃度の上昇が生体に与える影響を理解する上で有用な知見となる．また，長時間相互相関解析，方向依存フラクタル解析など，生体信号時系列の新たな解析法を開発し，その数学的基盤を確立した．本研究で開発した時系列の解析法は，生体信号時系列への適用に限らず，一般的な時系列解析に適用可能であり，広い応用が期待できる．