O'Brien Catherine, Berglund Larry G
Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA 01760-5007, USA.
Biophysics and Biomedical Modeling Division, US Army Research Institute of Environmental Medicine, Natick, MA 01760-5007, USA.
J Therm Biol. 2018 Aug;76:45-51. doi: 10.1016/j.jtherbio.2018.07.001. Epub 2018 Jul 5.
A two-compartment (core, skin) rational Canine Thermal Model (CTM) of thermal-physiological responses was developed to predict the core temperature (Tc) of a military working dog (MWD) during recovery from exertional heat stress. Heat storage is represented as the balance among heat loss mechanisms, heat gain from the environment, and heat production from metabolism. Inputs to the CTM include environmental conditions (ambient temperature, relative humidity, solar radiation and wind speed), physical characteristics of the dog (weight, length), and metabolic rate. The CTM was validated against Tc of 16 MWDs measured in a previous study, where training was conducted in October (24 °C, 52% RH), March (14 °C, 74% RH), and August (28 °C, 64% RH). Measured and CTM-simulated Tc were compared at 5, 10, 15, 30 and 60 min post-exercise. The CTM was considered acceptable if it was within 0.5 °C of measured Tc for 80% of cases. This occurred in 92% of 37 cases after 30 min recovery, and 86% of 29 cases after 60 min. The mean difference between CTM-simulated and measured Tc was - 0.01 °C at 30 min recovery, with 2 of 37 cases falling outside the range of two standard deviations (Bland Altman comparison). After 60 min recovery the difference was 0.05 °C, with 4 of 29 cases outside the range of acceptance. The root mean squared deviation between CTM-simulated and measured Tc for all time points was 0.3 °C ± 0.3 °C. For comparison, the mean ± standard deviation of resting Tc was 38.2 °C ± 0.3 °C and at peak Tc was 39.4 °C ± 0.7 °C. For this population, the CTM is a valid method for simulating recovery from exertional heat stress. It can be used to develop work / rest cycles during activity in hot environments, and to compare rates of recovery across different environmental conditions.
开发了一种双室（核心、皮肤）热生理反应的合理犬类热模型（CTM），以预测军犬在运动性热应激恢复过程中的核心温度（Tc）。蓄热表示为热损失机制、环境热增益和代谢产热之间的平衡。CTM的输入包括环境条件（环境温度、相对湿度、太阳辐射和风速）、犬的身体特征（体重、体长）和代谢率。CTM根据先前研究中测量的16只军犬的Tc进行了验证，该研究在10月（24°C，52%相对湿度）、3月（14°C，74%相对湿度）和8月（28°C，64%相对湿度）进行训练。在运动后5、10、15、30和60分钟比较测量的和CTM模拟的Tc。如果在80%的情况下CTM模拟值在测量的Tc的0.5°C范围内，则认为CTM是可接受的。在恢复30分钟后，37例中有92%出现这种情况，在恢复60分钟后，29例中有86%出现这种情况。在恢复30分钟时，CTM模拟的和测量的Tc之间的平均差异为-0.01°C，37例中有2例超出两个标准差范围（Bland Altman比较）。恢复60分钟后，差异为0.05°C，29例中有4例超出可接受范围。所有时间点CTM模拟的和测量的Tc之间的均方根偏差为0.3°C±0.3°C。作为比较，静息Tc的平均值±标准差为38.2°C±0.3°C，峰值Tc为39.4°C±0.7°C。对于该群体，CTM是模拟运动性热应激恢复的有效方法。它可用于制定炎热环境中活动期间的工作/休息周期，并比较不同环境条件下的恢复率。
