Cala S J, Kenyon C M, Ferrigno G, Carnevali P, Aliverti A, Pedotti A, Macklem P T, Rochester D F
Meakins-Christie Laboratories, Montréal, Québec, Canada.
J Appl Physiol (1985). 1996 Dec;81(6):2680-9. doi: 10.1152/jappl.1996.81.6.2680.
Estimation of chest wall motion by surface measurements only allows one-dimensional measurements of the chest wall. We have assessed on optical reflectance system (OR), which tracks reflective markers in three dimensions (3-D) for respiratory use. We used 86 (6-mm-diameter) hemispherical reflective markers arranged circumferentially on the chest wall in seven rows between the sternal notch and the anterior superior iliac crest in two normal standing subjects. We calculated the volume of the entire chest wall and compared inspired and expired volumes with volumes obtained by spirometry. Marker positions were recorded by four TV cameras; two were 4 m in front of and two were 4 m behind the subject. The TV signals were sampled at 100 Hz and combined with grid calibration parameters on a personal computer to obtain the 3-D coordinates of the markers. Chest wall surfaces were reconstructed by triangulation through the point data, and chest wall volume was calculated. During tidal breathing and vital capacity maneuvers and during CO2-stimulated hyperpnea, there was a very close correlation of the lung volumes (VL) estimated by spirometry [VL(SP)] and OR [VL(OR)]. Regression equations of VL(OR) (y) vs. VL(SP) (x, BTPS in liters) for the two subjects were given by y = 1.01x-0.01 (r = 0.996) and y = 0.96x + 0.03 (r = 0.997), and by y = 1.04x + 0.25 (r = 0.97) and y = 0.98x + 0.14 (r = 0.95) for the two maneuvers, respectively. We conclude spirometric volumes can be estimated very accurately and directly from chest wall surface markers, and we speculate that OR may be usefully applied to calculations of chest wall shape, regional volumes, and motion analysis.
仅通过表面测量来估计胸壁运动，只能对胸壁进行一维测量。我们评估了一种光学反射系统（OR），该系统可在三维空间（3-D）中追踪用于呼吸的反射标记物。我们在两名正常站立受试者的胸骨切迹和髂前上棘之间，沿胸壁圆周方向分七排排列了86个（直径6毫米）半球形反射标记物。我们计算了整个胸壁的体积，并将吸气和呼气时的体积与通过肺活量测定法获得的体积进行比较。标记物的位置由四个电视摄像机记录；两个在受试者前方4米处，两个在受试者后方4米处。电视信号以100赫兹进行采样，并在个人计算机上与网格校准参数相结合，以获得标记物的三维坐标。通过对这些点数据进行三角测量来重建胸壁表面，并计算胸壁体积。在潮式呼吸、肺活量动作以及二氧化碳刺激的深呼吸过程中，通过肺活量测定法估计的肺容积[VL(SP)]与OR法[VL(OR)]之间存在非常密切的相关性。两名受试者的VL(OR)（y）与VL(SP)（x，BTPS单位为升）的回归方程分别为y = 1.01x - 0.01（r = 0.996）和y = 0.96x + 0.03（r = 0.997），而两种动作的回归方程分别为y = 1.04x + 0.25（r = 0.97）和y = 0.98x + 0.14（r = 0.95）。我们得出结论，肺活量测定的体积可以非常准确且直接地从胸壁表面标记物中估计出来，并且我们推测OR可能有效地应用于胸壁形状、局部体积和运动分析的计算。
