[Effects of measurement position on the forced oscillation technique values]

Cheek support and subject's arm position can influence on lung function values measured with forced oscillation technique. We examined resistance and reactance by different methods using a new forced oscillation technique machine called MostGraph (Chest Co. Ltd., Tokyo, Japan).

We evaluated nineteen adults. Four methods are measured. 1: the subjects support their cheeks with their hands. 2: the tester support the subject's cheeks with their hands. 3: the subjects stiffen their cheeks without any cheek support. 4: subject relax their cheeks without any cheek support. R5, R20, R5-R20, X5, Fres and ALX were compared between four methods.

In resistance values, R20 was the lowest in the fourth method, and it was significantly different from the first (p<0.01) and the second (p<0.01) method. R5-R20 was the lowest in the second method, and it was significantly different from the third (p<0.01) and forth (p<0.01) methods. In reactance values, X5 was the highest in the second method. All ractance values in the second method were significantly different from the first and the fourth method.

Measurement values using Mostgraph was influenced by methods of supporting cheeks and subject's arm position. Measurement method should be unify and the first method is ideal and practical.