Electrical Measurement of Temperature Change Distribution in Living Bodies

活体体温变化分布的电测量体温是监测患者最重要的信息之一。有时临床上需要测量病人横切面的温度分布。了解肿瘤附近的温度分布对做好热疗非常重要。本文讨论了温度分布的两种电方法。a)高外加电频率下活体组织热特性的基础研究。b)研制用于测量活体温度分布的阻抗CT。用开放式同轴线测量组织介电常数温度系数。生物组织的电学特性受其自身温度的影响很大。本文测量了组织允许活动的温度系数，并讨论了该特性是否可以应用于活体温度分布的无创测量。电导率与其温度成正比。在低频时，盐溶液的介电常数随温度的升高而增大。在高频时反之亦然。在中频只有很小的变化。对一些生物材料也得到了类似的结果。因此，如果能得到更精确的结果，用这种方法对活体组织的温度变化进行无创测量似乎是可能的。如何无创地测量人体温度变化是热疗治疗中最重要的问题之一。组织电阻率温度系数很大，约为-2%/ C。我们通过二维阻抗CT测量组织电阻率的变化来估计温度的变化。本文给出了二维阻抗CT的实验和理论结果。实验结果表明，我们可以在+- 1个温度误差范围内估计温度变化，空间分辨率为1 cm^2。本文还从理论上讨论了估计误差。少

El electrical Measurement of Temperature Change Distribution in Living BodiesBody temperature Is one of the most important information for the monitoring of patients. And sometimes it is clinically desired to measure the temperature distribution in a cross section of a patient. For good hyperthermi treatment, to know the temperature distribution near tumor is very important. In this paper, two electrical methods for the temperature distribution are discussed.a)Basic research on the thermal characteristics of living tissues at high applied electrical frequencies.b)Development of a impedance CT for the measurement of temperature distribution in living bodies.1. Measurement of the Temperature Coefficients of Tissue Permittivities by Means of Open-Ended Coaxial Line.Electrical properties of biological tissues are greatly affected by it's own temperature. In this paper, we measure the temperature coefficient of tissue permit activities and discuss if this properties can be applied to the no … More n-invasive measurement of the temperature distribution in living bodies.The conductivity is proportional to its temperature. The dielectric constant of saline solution increases with the increase of temperature at low frequency. And is vise versa at high frequency. There are only a little change at middle frequency. The similar results are obtained for some biological materials. Therefore it seems to be possible to non-invasively measure the temperature change of living tissues by this method If more accurate results can be obtained.2. Measurement of Temperature Change by Impedance CTOne of the most important problems in hyperthermia treatment is how to noninvensively measure the temperature change in human body. The temperature coefficient of tissue resistivity is very large and about -2%/ﾟC. We have controled to estimate the temperature change by measuring the change of tissue resistivity by 2-D impedance CT. In this paper, we present the experimental and theoretical results by 2-D impedance CT.From experimental results, It Is concluded that we can estimate the temperature change within temperature error of +- 1ﾟC and space resolutlion of I cm^2. The estimation error was also theoretically discussed In this paper. Less