O2/CO2 분석기를 사용하여 폐의 기능적 잔기용량을 계측하는 질소세척법 개발

Abstract

Functional residual capacity(FRC) is an important diagnostic parameter measured using N2 analyzer. Since N2 analyzer is expensive as well as cumbersome for use of noisy vacuum pump, the FRC measurement becomes possible only in large well-equipped hospitals. The present study introduced a new N2 wash-out technique to measure FRC by O2/CO2 analysis, which is relatively cheaper and much simpler to apply. Slower O2 response was compensated for high frequency to be coincided with CO2 response, thereby enabled indirect, but accurate N2 concentration measurement. FRC was estimated by continuous integration of expired N2 volume obtained with air flow signal. Experiment with 3L syringe, a standard calibration device recommended by the American Thoracic Society, demonstrated less than 1% error at 0, 1, and 2L. Correlation coefficient was almost ideal, guaranteeing linear estimation of FRC. The present technique is inexpensive and simple to apply, thus should be of great convenience.