Title |
Accuracy Evaluation of Tidal Volume Measured on the Abdomen |
Authors |
이인광(Lee, In-Kwang) ; 김성식(Kim, Seong-Sik) ; 장종찬(Jang, Jong-Chan) ; 김군진(Kim, Koon-Jin) ; 김경아(Kim, Kyung-Ah) ; 이태수(Lee, Tae-Soo) ; 차은종(Cha, Eun-Jong) |
Keywords |
Conductive rubber cord ; Abdominal dimension measurement ; Tidal volume estimation ; Customized calibration |
Abstract |
Respiration is induced by muscular contraction of the chest and abdomen, resulting in the abdominal volume change. Thus, continuous measurement of the abdominal dimension enables to monitor breathing activity. Conductive rubber cord has been previously introduced and tested to develop wearable application for respiratory measurements. This study implemented respiratory monitoring system with the conductive rubber cord in the patient's pants in purpose of quantitative estimation of tidal volume. Air mixed with 0~5% CO_2 was inhaled and the respiratory air flow rate, abdominal dimension change, and end tidal CO_2 concentration were simultaneously measured in steady state. CO_2 inhalation significantly increased the tidal volume in normal physiological state with the subject unawared. The tidal volume estimated from the abdominal dimension change linearly correlated with the tidal volume measured by a pneumotachometer with a correlation coefficient of 0.88. Customized calibration for each subject resulted in relative errors less than 10%. Therefore, the tidal volume was accurately estimated by measuring the abdominal dimension change. |