Abstract
Forced oscillation technique (FOT) has been recognized as a method to measure lung function. Recently, a new FOT machine, MostGraph (Chest Co., Ltd., Tokyo, Japan), has been developed. As FOT only requires the subject to breathe normally, it will be particularly useful for children for whom cooperation is difficult. Coherence values reflect the reproducibility of a typically normal breath. A coherence value of 0.7 was regularly used for MostGraph measurement. As no previous report to date has shown a coherence value of 0.7 to be a valid value, we evaluated whether a coherence value of 0.7 is suitable for children. We evaluated 131 school children and measured lung function by using MostGraph. We compared MostGraph parameters (R5, R20, R5-R20, X5, Fres, and ALX) between three different coherence values (0.7, 0.8, 0.9). We evaluated ninety-five healthy children (mean age: 7.6 ± 1.4 years old), and excluded children with complications. MostGraph parameters showed no significant difference between three values in all respiratory phases. A coherence value of 0.7 was appropriate to measure the lung function of children by using MostGraph.
