Lafortuna C L, Passerini L
Istituto di Tecnologie Biomediche Avanzate del C.N.R., Reparto di Fisiologia del Lavoro Muscolare, Milan, Italy.
Eur J Appl Physiol Occup Physiol. 1995;71(2-3):259-65. doi: 10.1007/BF00854988.
A simple and inexpensive new extensometer for measuring changes in chest wall circumference during human respiratory movements is presented. The instrument detects the delay between ultrasound emission and reception at opposite ends of two rubber tubes encircling the rib cage and abdomen. Assuming a two degree of freedom model of the chest wall and employing an isovolume procedure for determination of volume-motion coefficients, extensometer estimation of tidal volume (VT) from changes of rib cage and abdomen circumference was compared with spirometer measurements at rest and during exercise on a cycle ergometer (55-155 W) in six subjects and, in four of them, on a treadmill (4-12 km.h-1). In three subjects hypercapnic hyperpnoea at rest was also studied. The slopes of the linear relationship between extensometer and spirometer VT (litres) averaged 0.9967 (SD 0.0117) (r2 = 0.995-0.998; n = 90-143) for cycle ergometer exercise, 1.0072 (SD 0.0078) (r2 = 0.991-0.998; n = 75-93) for treadmill exercise and 0.9942 (SD 0.0188) (r2 = 0.997-0.998; n = 18-25) for hypercapnic hyperpnoea. In all instances the slope of the regression line was consistent with the model of the identity line (slope = 1). The changes in end-expiratory lung volume between respiration at rest and during exercise were determined by the extensometers, and were nearly identical (98.4% on average) to those measured with the spirometer (r2 = 0.945; n = 24). It is concluded that determination of chest wall circumference with this new instrument is suitable for quantitative measurement of ventilation and lung volume variations in humans under most physiological conditions.
本文介绍了一种简单且廉价的新型伸长计，用于测量人体呼吸运动期间胸壁周长的变化。该仪器检测环绕胸腔和腹部的两根橡胶管两端超声波发射与接收之间的延迟。假设胸壁为两自由度模型，并采用等容程序确定体积 - 运动系数，在六名受试者中，将根据胸廓和腹部周长变化通过伸长计估算的潮气量（VT）与在休息时以及在功率自行车（55 - 155瓦）上运动期间的肺活量计测量值进行比较，其中四名受试者还在跑步机（4 - 12千米·小时⁻¹）上进行了测量。对三名受试者在静息时的高碳酸血症性通气过度也进行了研究。对于功率自行车运动，伸长计与肺活量计测量的VT（升）之间线性关系的斜率平均为0.9967（标准差0.0117）（r² = 0.995 - 0.998；n = 90 - 143）；对于跑步机运动，斜率为1.0072（标准差0.0078）（r² = 0.991 - 0.998；n = 75 - 93）；对于高碳酸血症性通气过度，斜率为0.9942（标准差0.0188）（r² = 0.997 - 0.998；n = 18 - 25）。在所有情况下，回归线的斜率与恒等线模型（斜率 = 1）一致。通过伸长计确定了静息呼吸和运动期间呼气末肺容积的变化，这些变化与用肺活量计测量的结果几乎相同（平均98.4%）（r² = 0.945；n = 24）。结论是，使用这种新仪器测量胸壁周长适用于在大多数生理条件下对人体通气和肺容积变化进行定量测量。
