title: [Studies on the deviation of short-term FRC measurements with He closed-circuit method and on diurnal variation of FRC].
abstract: It was revealed by chance that the second FRC value measured by Chest Chestac 65V was significantly smaller than the first FRC value measured by Fukuda FRC Computer COMF-100 if the second repeated measurement in the same subjects was done shortly after the first FRC measurement with He closed-circuit method was performed. In order to clarify this phenomenon, the volumes of two different machines were accurately checked by a cylinder. No significant differences were found in the FRC values of two machines. In adult healthy subjects a small but significant difference between the first and the second ten minutes behind measurement was found even if the same machine was used. If FRC measurement was reexamined within a few minutes after the first one was done, much differences were found. Furthermore, diurnal variation of FRC values in the same subjects was also observed. FRC value in the morning was the highest.
authors.affiliation: Department of Clinical Laboratory, Hyogo College of Medicine, Nishinomiya.
authors.forename: H
authors.initials: H
authors.lastname: Shibata
authors.forename: O
authors.initials: O
authors.lastname: Horie
authors.forename: M
authors.initials: M
authors.lastname: Sugita
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D005260:Female; D005652:Functional Residual Capacity; D006371:Helium; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008722:Methods; D008875:Middle Aged; D013997:Time Factors
chemical_list: D006371:Helium