Bell P Y, Padbury E H, Hayes P A
Undersea Biomed Res. 1985 Dec;12(4):465-83.
Regional heat flux (intensity of heat flow rate, W m-2) was measured using heat flux transducers affixed to the skin surface at 14 sites on the left arm and 15 sites on both the left leg and the trunk (total of 44 locations) of human subjects during head-out immersion in water at temperatures between 11 and 28 degrees C. The heat flux data and skin temperature data were collected continuously over a 30-min period taking approximately 2.5 min to scan through all transducers in sequence before repeating the process. There were 3 immersions per individual, monitoring the arm or the leg or the trunk. The local measurements of heat flux from each of the body segments were summated and meaned to obtain a value of overall flux for each area of the body for each 2- to 3-min interval. This mean value was taken as the optimal value (Hopt) for any particular body segment. Every permutation of the positions of any 1, 2, 3, 4, or 5 heat flux transducers from the possible 14 or 15 sites was used to obtain a mean value which could be compared to the Hopt over the total duration of each immersion. Comparisons could be made between the best individual sites (Iopt) and Hopt as well as between the overall best site for the group of 10 people (Gopt) and Hopt. All possible permutations could be ranked in ascending order of preference based on a decreasing sum of the squares of the differences between Hopt and either Iopt or Gopt. Confirmation of the validity of this simple ranking system was based on an analysis of the percentage differences between Iopt or Gopt and Hopt. Such an analysis indicated that the better choice of discs when using a small number of transducers was between 3 and 5 sites, affording both reasonable accuracy and practicality. It is recommended that between 3 and 5 discs be used per body segment at specific locations and the calculated heat loss from each segment be weighted according to its area of representation to give a value for the mean rate of total body heat loss. A reasonable level of accuracy was demonstrated using Gopt permutations for measuring both the rate of heat flow as well as the integral of the data to obtain a value of the quantity of heat (Joules) lost from the body.
在人体受试者头部露出浸泡于11至28摄氏度的水中时，使用贴附于皮肤表面的热通量传感器，在左臂的14个部位以及左腿和躯干的各15个部位（共44个位置）测量局部热通量（热流率强度，单位：W m-2）。热通量数据和皮肤温度数据在30分钟内持续收集，在重复该过程之前，大约需要2.5分钟依次扫描所有传感器。每个受试者进行3次浸泡，分别监测手臂、腿部或躯干。对每个身体部位的局部热通量测量值进行求和并求平均值，以获得每个身体区域在每2至3分钟间隔内的总通量值。该平均值被视为任何特定身体部位的最佳值（Hopt）。从可能的14个或15个部位中选取1、2、3、4或5个热通量传感器位置的每一种排列，用于获得一个平均值，该平均值可在每次浸泡的总持续时间内与Hopt进行比较。可以比较最佳个体部位（Iopt）与Hopt，以及10人组的总体最佳部位（Gopt）与Hopt。所有可能的排列可根据Hopt与Iopt或Gopt之间差异平方和的递减顺序按偏好升序排列。基于对Iopt或Gopt与Hopt之间百分比差异的分析，证实了这个简单排序系统的有效性。这样的分析表明，使用少量传感器时，较好的圆盘选择是3至5个部位，兼具合理的准确性和实用性。建议在特定位置每个身体部位使用3至5个圆盘，并根据每个部位的代表面积对计算出的每个部位的热损失进行加权，以得出全身热损失平均速率的值。使用Gopt排列测量热流率以及数据积分以获得身体散失的热量（焦耳）值时，展示了合理的准确度水平。
