Background: 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).
Methods: 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.
Results: 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.
Conclusion: 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.