SELF HEATED THERMISTORS TO QUANTIFY TISSUE PERFUSION

这项研究的目的是将数值、分析、 三名调查人员的实验和医学专长，以便 开发一种改进的测量热量的诊断技术 使用微型传导性、热扩散率和灌流 自热式热敏电阻探头。拟议的研究将有四个主要方面 努力。第一项任务将使用有限元数值分析来 优化热敏电阻探头设计和测量方案。第二 任务将是一个详尽的实验误差分析，使用 大鼠肝脏制剂。第三个任务将是收集In 体外热物性数据库。导热系数和扩散系数 人体活体组织和尸检组织将被测量。第四项任务是 将实施现有的基于微型计算机的临床版本 乐器。机构审查委员会批准了这一文书，并 将需要表面热敏电阻探头，以便将来进行 临床研究。 将稳态和正弦热功率的组合输送到 一种球形热敏电阻，可侵入性地放置在组织内或 非侵入性地在组织的表面上。热度被带走了 通过热传导和灌流进入组织的探头。有限的 用单元法数值求解了两相流之间的换热问题 加热的热敏电阻和灌流的组织。电力和电力系统 由此产生的温升由微型计算机仪器测量。 这些测量被用来计算有效导热系数 它代表了生物热的传导和对流成分 调职。由于组织血液流动强烈影响局部热传递， 该仪器对灌流相当敏感。 这项提案的资金将转化为长期的改善。 在病人护理方面。

The objective of this research is to combine the numerical, analytic, experimental, and medical expertise of the three investigators in order to produce an improved diagnostic technique for measuring thermal conductivity, thermal diffusivity, and perfusion using miniature self-heated thermistor probes. The proposed research will have four major efforts. The first task will use finite element numerical analysis to optimize the thermistor probe design, and measurement protocol. The second task will be an exhaustive experimental error analysis using an isolated rat liver preparation. The third task will be the collection of an in vitro thermal property data base. The thermal conductivity and diffusivity of human biopsy, and autopsy tissue will be measured. The fourth task will be to implement a clinical version of the existing microcomputer based instrument. Institutional Review Board approval of this instrument, with surface thermistor probes, will be requested in order to conduct future clinical studies. A combination of steady state and sinusoidal thermal power is delivered to a spherical thermistor positioned invasively within a tissue or noninvasively on the surface of a tissue. The heat is carried away from the probe into the tissue by thermal conduction, and perfusion. The finite element method is used to numerically solve the heat transfer between the heated thermistor and the perfused tissue. The electrical power and the resulting temperature rise are measured by the microcomputer instrument. These measurements are used to calculate the effective thermal conductivity which represents both the conductive and convective components of bioheat transfer. Because tissue blood flow strongly affects local heat transfer, the instrument is quite sensitive to perfusion. The funding of this proposal will translate into a long lasting improvement in patient care.