Measurement of Body Density by Means of He Replacement Method

He置换法测量人体密度

• 批准号: 07557035
• 负责人: YAJIMA Kazuyoshi
• 金额: $ 8.9万
• 依托单位: Nihon University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07557035/
• 关键词: Body Density; He gas Replacement Method; Body Composition; % Fat; 人体体積計; ヘリウムガス置換方式; 体密度; 体脂肪; 肥満判定; 肥満測定

To obtain body density, highly precise measurement of body volume and body weight is essential. Conventionally body volume has been measured by immersing the subject completely in the water. Yet to ensure an extreme precision by this method, complicated calculations are necessary to obtain the gas amount remaining in the lungs. We have relied on the measurement by air replacement for this purpose, but the pressurization during the process has caused substantial discomfort to the subject, and effective method for measuring body volume.Having devised an apparatus to measure body volume by replacing it with diluted helium without pressurization, we examined the parameters affecting the measurement precision and evaluated the device's scientific aptitude in comparison with the water-immersion method.To obtain a more accurate value of body volume the capacity of the apparatus should be minimized as far as equal distribution of He gas is ensured. Another condition is that the measurement sho … More uld be made in the area of a high He concentration. A 1 liter change in body volume results in a change in the He concentration of 0.01% in an apparatus of 1000 liter and 0.005% in that of 2000 liter. As 0.05% is the measurable limit for our trial production, the He concentration at the measurement point should be 20% to yield a precision of 0.01% in an apparatus of 1000 liter capacity.The measurement conditions were : the apparatus capacity is 850.508 liter ; He-gas introduction rate is 25 l/min ; He-gas volume introduced were 100-120 liter (final He concentration were 10-15%). The increase in the atmospheric pressure from the He-gas introduction ranged between 0.12-0.15 mmHg. It was crucial to maintain airtightness.In an experiment with a water bag of known volume, the correlation coefficient for the values measured by this method was estimated at 0.994. When the measurements on 15 subjects were compared between this and the He replacement method, the correlation coefficient stood at 0.89. Less

为了获得身体密度，高度精确地测量身体体积和体重是必不可少的。传统上，人体体积是通过将受试者完全浸入水中来测量的。然而，为了确保这种方法的极端精度，需要进行复杂的计算，以获得肺中剩余的气体量。为此，我们一直依靠空气替代测量，但在此过程中加压对受试者造成了很大的不适，这是测量人体体积的有效方法。我们设计了一种用稀释氦气代替不加压的人体体积测量装置，研究了影响测量精度的参数，并与水浸法进行了比较，评估了该装置的科学性。为了获得更精确的体体积值，在保证He气体均匀分布的情况下，应尽量减少仪器的容量。另一个条件是，在He浓度高的区域会有更多的测量结果。人体体积变化1升，在1000升的仪器中He浓度变化0.01%，在2000升的仪器中He浓度变化0.005%。由于0.05%是我们试验生产的可测量极限，测量点的He浓度应为20%，以便在1000升容量的仪器中产生0.01%的精度。测量条件为：仪器容量为850.508 l；He-gas引入速率为25l /min；引入He气量100-120 l（终He浓度10-15%）。引入氦气导致的大气压力增加在0.12-0.15 mmHg之间。保持密封性是至关重要的。在已知体积的水袋实验中，该方法测量值的相关系数估计为0.994。将15名受试者的测量结果与He替代法进行比较，相关系数为0.89。少

项目成果

伊藤雅夫、谷島一嘉他: "ヘリウムガス置換方式による体比重の測定" 日本衛生学会雑誌. 52・1. 267 (1997)

Masao Ito、Kazuyoshi Tanishima 等：“使用氦气置换法测量身体比重”日本健康科学学会杂志 52, 1. 267 (1997)。

伊藤雅夫: "ヘルウムガス置換方式による体比重の測定" 日本衛生学雑誌. 52・1. (1997)

伊藤正夫：“使用氦气置换法测量身体比重”日本卫生杂志52·1（1997）。