Thermophysical properties of swine myocardium
Thermophysical properties of swine myocardium
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DOI：
10.1023/a:1022673524963
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发表时间：
1999-03-01
影响因子：
2.2
通讯作者：
Valvano, JW
中科院分区：
文献类型：
--
作者：
Bhavaraju, NC;Valvano, JW
本文介绍了猪心肌组织热导率、热扩散率和密度的实验方法和结果。测量新鲜切除组织的这些特性。使用自热式热敏电阻探针测量热性能，而使用水置换法测量密度。将热敏电阻探针插入感兴趣的组织中，并用于在组织内供热以及监测组织中的温升。使用经验校准程序来测量组织在不同温度下的特性。首先在每个温度下用琼脂凝胶水和甘油校准测量仪器。在25、37、50、62和76摄氏度的温度下进行测量。测量的不确定度范围从较低温度下的2%到较高温度（T > 50 ℃）下的约5%。组织的性质在很大程度上取决于含水量。在高于50摄氏度的温度下，在手术过程中组织会有显著的水分流失。水的损失被发现随温度相对于环境的增加呈指数变化。因此，随着温度的升高，热导率值降低。然而，这种减少并不像人们从水分流失数据中预期的那样多。提出了一个假设来解释水分损失，细胞损伤和热性能之间的关系。
This paper presents the experimental technique and results for the thermal conductivity, thermal diffusivity, and density of swine myocardial tissue. These properties were measured for freshly excised tissue. Thermal properties were measured using a self-heated thermistor probe, while the density was measured using a water displacement method. Thermistor probes were inserted into the tissue of interest and were used to supply heat within the tissue as well as to monitor the temperature rise in the tissue. An empirical calibration procedure was used to measure the properties of the tissue at different temperatures. The measurement instrument was first calibrated against agar-gelled water and glycerol at each temperature. The measurements were made at temperatures of 25, 37, 50, 62, and 76 degrees C. The uncertainty in the measurement ranges From 2% at lower temperatures to about 5% at higher temperatures (T > 50 degrees C). The properties of the tissue depend significantly on the water content. At temperatures higher than 50 degrees C, there is significant water loss from the tissue during the procedure. The water loss is found to vary exponentially with the increase in temperature relative to ambient. Consequently, there is a decrease in the thermal conductivity values with increasing temperature. This decrease, however, is not as much as one would expect From the water loss data. A hypothesis to explain the relationships among water loss, cell damage, and thermal properties is proposed.