The maximum voluntary ventilation (M VV) is one of the most widely used pulmonary function test, but its measuring method was very difficult ´ and unreliable. However, it is need to get more easy and simple measuring method of MVV.
Therefore, this study was, attempted to get more easy and simple measuring method of MVV by means of the forced expiratory volume (FEV_T). The young and healthy 1, 000 Korean students (592 male and 408 female) were choosed foe-this purpose and whose ages were from 8 to 20 years.
A spirometer (9L, Collins Co.) was used, for the MVV and FEV, and they were measured 3: times at standing position, and the highest value was used. In the measurements, the" subjects for MVV were asked for the breath as fast and deeply as possible for 12 seconds, and for FEV were asked for the rapid and forceful exhalation after a maximal inhalation (forced expiratory curve).,
In the FEV measurements toward the end of the expiration, the subjects were exhaused tocontinue the effort until no further gas was expired. During these measurements, the, investigator stood by the subject to give a constant encouragement.
FEV were calculated in the volume exhaled during the one-half (FEV_0.1, ml), the first second. (FEV_0.5 ml) and the percentage of the total vital capacity exhaled during the one-half second (FEV_0.5, ml).
The results are summarized as follows:
1) The values of MVV were increased linearly with ages until 20 in both sexes. The values. of male at the age of 20 was 168.2±2.5L/min, and female at the age of 17 was 11.2.3±3.OL/ min, respectively.
2) The values of FEV (ml) were increased linearly with ages until 20 in both sexes. Thevalues of FEV_0.5 were 2, 797+65.7m1 in the male of 20 years and were 2, 088±54.6ml , in the: female of 17 years, and of FEV_1.0 were 4,119±68.2m1 in, the. male of 20 years and were 2,897 --3°65.9m1 in the female of 17 years, respectively.
3) The correlation coefficients between MVV and FEV_0.5 or FEV_1.0 (ml) were 0. 82 or 0.85 in the male, and 0.77 or 0.79 in the female, respectively.
4) The prediction formulae for MVV to be derived from above results were.
For male: MVV (L/min)=7.19+0.05XFEVo.s(ml)
MVV (L/min)=11.25+0.04XFEV1.o(ml)
For female: MVV (L/min)=16.03+0.05XFEVo.s(ml)
MVV (L/min)=9.47+0.O3XFEVt.o(ml)
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