ELECTRICAL IMPEDANCE CHANGE WILTH HYPERTHERMIA DAMAGE

热疗是目前肿瘤治疗技术中的一种 对治疗的具体影响知之甚少， 组织进行准确的预后。目前，没有简单的技术可以 获取所需的数据。具体目标;将进行一项研究， 建立使用组织的体内测量的可行性 电阻抗，用于确定和监测 临床高热假设：当组织受到 治疗性热疗，这些变化代表了实际的细胞损伤， 将反映在这些细胞的膜损伤程度上。以来 组织的低频电阻抗主要是由于 细胞膜的特性、体内测量的阻抗 将提供数据，从这些数据中， 测定 为了验证这一假设，该项目将确定 确定了组织对高温反应的一般特征 可以从电阻抗的体内测量确定 在热疗期间和之后。实验设计和方法： 组织的复电阻抗将在频率 范围从10 Hz到100 MHz，在热疗应用期间和之后， 使用阻抗分析仪、体内小的可植入电极，以及 电极或平行板电容器几何形状。的 实验概要如下：1.电极变量的确定; 2. 温度分布图;以及3.高温实验， 切除的组织和体内。 对于体内测量，成年大鼠的大腿肌肉和生长的肿瘤 将使用裸鼠。统一的治疗温度将是 快速达到，并在测量期间定期测量电阻抗。 以及在热疗之后，在已知温度的区域中。温度 将保持在+/-.5摄氏度。

The cancer treatment technique of therapeutic hyperthermia currently suffers from too little knowledge of the specific effects on the treated tissues for accurate prognosis. Currently, no simple technique exists to obtain the needed data. SPECIFIC AIMS; A study will be conducted to establish the feasibility of using in vivo measurements of tissue electrical impedance for determining and monitoring the effect of clinical hyperthermia. Hypothesis: When a tissue is subjected to therapeutic hyperthermia, the changes representing actual cell damage will be reflected in the extent of membrane damage to those cells. Since the low frequency electrical impedance of tissues is predominently due to the characteristics of the cell membranes, the in vivo measured impedance will provide data from which the clinical effect of hyperthermia can be determined. To test this hypothesis, the project will determine whether the established general characteristics of tissue response to hyperthermia can be ascertained from in vivo measurements of the electrical impedance during and after hyperthermia. EXPERIMENTAL DESIGN AND METHODS: The tissue's complex electrical impedance will be measured in the frequency range from 10Hz to 100MHz, during and following hyperthermia application, using an impedance analyzer, small implantable electrodes in vivo, and electrodes or parallel plate capacitor geometry for excised tissue. The experimental outline follows: 1. determination of electrode variables; 2. mapping of temperature distributions; and 3. hyperthermia experiments in excised tissues and in vivo. For in vivo measurements the thigh muscles of adult rats and tumors grown in nude mice will be used. Uniform therapeutic temperatures will be quickly reached and the electrical impedance periodically measured during and after the hyperthermia, in regions of known temperature. Temperature will be held at +/-.5deg C.