Analysis of the Weinbaum-Jiji model of blood flow in the canine kidney cortex for self-heated thermistors.
Analysis of the Weinbaum-Jiji model of blood flow in the canine kidney cortex for self-heated thermistors.
复制标题
自加热热敏电阻的犬肾皮质血流 Weinbaum-Jiji 模型分析。
DOI：
10.1115/1.2895720
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Anderson,GT
中科院分区：
文献类型：
--
作者：
Valvano,JW;Nho,S;Anderson,GT
Weinbaum-Jiji方程可应用于以下情况：1）血管解剖结构已知; 2）血液速度已知; 3）有效建模体积包括许多血管;以及4）与血管的实际长度相比，血管平衡长度较小。在稳态加热的热敏电阻放置在肾皮质中的情况下，这些标准得到满足。本文利用温鲍姆-吉吉生物热方程分析了四种不同尺寸的自热式热敏电阻在犬肾内的稳态响应。该传热模型是根据犬肾皮质血管的实际物理测量结果开发的。在该模型中，直径为60 μm的平行结构的小叶间小动脉和小静脉在血液流动引起的热传递中起主导作用。向热敏电阻施加连续电源，仪器测量由此产生的稳态温升。如果一个准确的热模型是可用的，灌注可以从这些稳态测量计算。有限元模拟在形状和振幅方面与犬肾的实验结果有很好的相关性。此外，本文表明，Weinbaum-Jiji方程不能用来模拟热敏电阻的瞬态响应，因为建模体积不包括足够的血管和血管平衡长度不小相比，实际长度的血管。
The Weinbaum-Jiji equation can be applied to situations where: 1) the vascular anatomy is known; 2) the blood velocities are known; 3) the effective modeling volume includes many vessels; and 4) the vessel equilibration length is small compared to the actual length of the vessel. These criteria are satisfied in the situation where steady-state heated thermistors are placed in the kidney cortex. In this paper, the Weinbaum-Jiji bioheat equation is used to analyze the steady state response of four different sized self-heated thermistors in the canine kidney. This heat transfer model is developed based on actual physical measurements of the vasculature of the canine kidney cortex. In this model, parallel-structured interlobular arterioles and venules with a 60 μm diameter play the dominant role in the heat transfer due to blood flow. Continuous power is applied to the thermistor, and the instrument measures the resulting steady state temperature rise. If an accurate thermal model is available, perfusion can be calculated from these steady-state measurements. The finite element simulations correlate well in shape and amplitude with experimental results in the canine kidney. In addition, this paper shows that the Weinbaum-Jiji equation can not be used to model the transient response of the thermistor because the modeling volume does not include enough vessels and the vessel equilibration length is not small compared to the actual length of the vessel.