Valvano J W, Allen J T, Bowman H F
J Biomech Eng. 1984 Aug;106(3):192-7. doi: 10.1115/1.3138482.
An improved technique is presented for the "in-vivo" determination of thermal conductivity, thermal diffusivity, and perfusion using a self-heated spherical thermistor probe. In the presence of flow, solution of the time-dependent, probe-tissue coupled thermal model allows the measurement of "effective" thermal conductivity and "effective" thermal diffusivity, which represent the thermal properties of the perfused tissue. Perfusion can be quantified from both "effective" thermal properties. In the presence of flow, it has been shown that the transient power responses does not follow t-1/2 as has been previously assumed. An isolated rat liver preparation has been developed validate the measurement technique. Radioactive microspheres are used to determine the true perfusion from the total collected hepatic vein flow. Experimental data demonstrates the ability to quantify perfusion in small volumes of tissue.
本文介绍了一种改进技术，用于使用自热球形热敏电阻探头“体内”测定热导率、热扩散率和灌注率。在有血流的情况下，求解随时间变化的探头-组织耦合热模型，可测量“有效”热导率和“有效”热扩散率，它们代表了灌注组织的热特性。灌注率可从这两种“有效”热特性中量化得出。在有血流的情况下，已表明瞬态功率响应并不像先前假设的那样遵循t-1/2规律。已开发出一种离体大鼠肝脏标本以验证该测量技术。放射性微球用于从总收集的肝静脉血流中确定真实灌注率。实验数据证明了对小体积组织中的灌注率进行量化的能力。
