12 Seconds As Correct And Sufficient. It Is Necessary

12 seconds as correct and sufficient. It is necessary to remember that 2 greatest in the test Volume for FVC and 2 greatest of volume for FEV1 in one test Should change no more than on 0.15 L (or on 0.1 L, if most Great volume <1 L). Recent research of problems of errors in the beginning Testings PFT (measurement FEV1) has shown that the relative Prevalence ordinary does not exceed 2 % in the same row, and frequency Problems of errors increase to 61-84 % by the end of the period of carrying out of test (measurement FVC). Survey of curves volume-stream in the test report Help to identify excessively early end of an exhalation and to estimate Presence (or absence) a plateau on an exhalation (illustration sm). And absence of a plateau on an exhalation from 12 to 15 Seconds of time of an exhalation are guaranteed by sufficient quality of record FVC. At survey of the beginning of a loop volume-stream it is possible To identify as the unstable beginning of record which is possible To accept as is false low beginning of a line at estimation FEV1.