摘要
本文在正常老青少年1486例和慢阻肺(COPD)患者168例的最大呼气流量—容积(MFFV)曲线上,用Knudson的弦线法于高中低肺容积处的弦线时间常数,τch75、τch50、τch25和本文采用的容积校正的比时间常数(Sτ) 1/75、1/50、1/25进行了系统探讨。在IBM-PC/XT计算机上建立青少年组和成年组各指标的回归方程。应用COPD患者各指标实测值占预计值的百分数和t检验,以估计疾病改变的程度。结果表明,各τch均随年龄而延长;青少年τch随肺内容积的衰减而缩短,老年人则随其衰减而延长。1/在青少年中随年龄而缩短,成年以后则随年龄而延长,1/在老中青少年中均随肺内容积的衰减而延长。COPD患者τch和1/的改变为:肺心病>300％,肺气为170～280％,慢支为110～180％。较MEFV曲线更为敏感,具有临床应用前景。本文讨论了上述指标的生理及临床意义。
A systematic exploration of the chord time constants, τch_(75), τch_(50), τch_(25) and specific time constants (Sτ) , 1/_(75), 1/_(50), 1/V_(25) were calculated with chord method from the maximal expiratory flow-volume (MEFV) curves of normal 1486 adolescent, middle aged and old persons and of 168 cases of chronic obstructive pulmonary disease (COPD) patients. The multiple regression equations of above indices in adolescent and adult groups were built by multiple stepwise regression analysis with IBM-PC/XT computer. τch_(75) and τch_(50) were compared with the mid-expiratory time constants, τMET, and the first second time constant, τFEV_1, to explore their relationships. The percentage of measured value over predicted value of the patients and test were used to estimate the degree of change in diseases.The dynamic changes of τch and 1/ with age demonstrsted that τch_(75)τch_(50), τch_(25) were lengthened with age in all groups, while 1/_(25) were shortened with age in adolescents, but prolonged in adults. The dynamic changes with lung volumes showed that τch were shortened with the decay of lung volumes in adolescents, but they were prolonged in the old; whereas 1/ were lengthened markedly with the decay of lung volumes in all age groups, especially in 1/_(25) for old persons. The differences between τch and 1/ suggested that the volume corrected Sτ (1/) could reliably reflect the changes of pulmonary mechanics and had a good correspondence of the lung recoil and resistance with the dynamic changes of age and lung volume. On comparison of τMEFT and τFEV_1 with the measured τch_(75) and τch_(50),the t tests showed no significant differences only between τch_(50) and τMET. This suggested that the FVC-t curve could not be determined by a single exponentral relationship, and that it might be an easy and reliable method to estimate _τch_(50) from _τMET. The _τch and S_τ in COPD patients showed the percentages of measured value over predicted value were:corpulmonale, >300%, emphysema, 170—280%, chronic bronchitis) 110—180%. The indices were more sensive than MEFV curves, and showed a good perspective for clinical practice.Their physiological and clinical significances were discussed.
出处
《生物医学工程学杂志》
EI
CAS
CSCD
北大核心
1990年第4期265-272,共8页
Journal of Biomedical Engineering
关键词
慢阻肺
MEFV
呼吸力学
肺阻力
Chronic obstructive pulmonary disease (COPD), maximal expirataory flow-volumo (MEFV), pulmonary mechanics
