Wells J C, Douros I, Fuller N J, Elia M, Dekker L
Childhood Nutrition Research Centre, Institute of Child Health, London, England.
Ann N Y Acad Sci. 2000 May;904:247-54. doi: 10.1111/j.1749-6632.2000.tb06460.x.
Measurement of body volume (BV) can be used to estimate body composition using two- or multicomponent models. The traditional approach, underwater weighing (UWW), is awkward and unsuitable for many subjects. A newer alternative, whole body air displacement plethysmography (ADP), is less demanding but still unsuitable for young children, who may not remain still during the measurement. We have, therefore, considered whether a novel approach, three-dimensional photonic scanning, is a viable alternative. Duplicate measurements of body volume were obtained in 22 adults (11 of each sex; mean [SD] BMI, 21.8 [2.5] kg/m2) by UWW, ADP, and a Hamamatsu Bodyline Scanner (HBS) (Hamamatsu, Japan). Subjects wore a tight-fitting swimming costume for all three measurements, which were performed within one day of each other. Scans lasted 10 seconds, with the subject standing in a predefined position. The body surface skin was reconstructed using a B-spline-fitting model. In UWW, lung volume (LV) was measured simultaneously with underwater weight. In ADP and HBS, LV was predicted from weight and height. Results were compared using correlation and Bland and Altman analysis. Correlation analysis indicated that the scanner successfully ranked subjects in terms of BV. However, Bland and Altman analysis demonstrated that, relative to both UWW and ADP, HBS measured BV without bias but with limits of agreement between individuals of > 2 liters, equivalent to approximately 20% fat. Scan precision was 0.57 liter, or 4.1% fat. Although HBS cannot yet measure BV with sufficient accuracy to predict fatness, much of the error is probably due to difficulties in standardizing LV during the scan. Simultaneous measurement of LV with volume by HBS is expected to improve limits of agreement substantially. Occlusion is also an important source of error. The method offers many advantages over alternative techniques, because the measurement is brief, noninvasive, and suitable for repeat measurements.
身体体积（BV）的测量可用于通过双组分或多组分模型估计身体成分。传统方法——水下称重（UWW）操作不便，不适用于许多受试者。一种较新的替代方法——全身空气置换体积描记法（ADP）要求较低，但仍不适用于幼儿，因为他们在测量过程中可能无法保持静止。因此，我们考虑了一种新方法——三维光子扫描是否是一种可行的替代方法。通过UWW、ADP和一台滨松人体轮廓扫描仪（HBS）（日本滨松），对22名成年人（男女各11名；平均[标准差]BMI为21.8[2.5]kg/m²）的身体体积进行了重复测量。在所有三次测量中，受试者均穿着紧身泳衣，且三次测量在一天内完成。扫描持续10秒，受试者站在预定义位置。使用B样条拟合模型重建身体表面皮肤。在UWW中，同时测量水下重量和肺体积（LV）。在ADP和HBS中，根据体重和身高预测LV。使用相关性分析以及布兰德和奥特曼分析对结果进行比较。相关性分析表明，扫描仪能够根据BV成功地对受试者进行排序。然而，布兰德和奥特曼分析表明，相对于UWW和ADP，HBS测量的BV无偏差，但个体间的一致性界限大于2升，相当于约20%的脂肪。扫描精度为0.57升，或4.1%的脂肪。尽管HBS目前还无法以足够的精度测量BV来预测肥胖程度，但大部分误差可能是由于扫描过程中标准化LV存在困难。预计通过HBS同时测量LV和体积将大幅提高一致性界限。遮挡也是一个重要的误差来源。该方法相对于其他技术具有许多优势，因为测量过程简短、无创且适合重复测量。
