新型各向异性组织介电特性在体测量射频探头仿真研究

The simulative study of a new probe for the in vivo dielectric measurement of anisotropic tissue in radio frequency band

本文提出了一种新型探头设计方案。该探头可通过一次操作,完成射频段各向异性的生物组织其介电特性在正交方向上的在体测量。通过仿真实验,本文在1~1 000 MHz频段内针对探头尺寸参数对极板间能量耦合度和探头测量灵敏度的影响进行了研究。针对该频段内的实际测量需求,给出了探头的具体设计方案,并验证了该探头的测量效果。仿真结果显示,在200~400 MHz内,该探头能够将极板间能量耦合度控制在–12 d B以下,并能保持对各向异性生物组织其介电特性的测量具有较高的灵敏度。仿真结果表明,该探头在射频段内对各向异性的生物组织其介电特性有良好的测量能力,避免了传统测量方法因多次操作而造成的测量误差,为各向异性的生物组织其介电特性在体测量技术研究提供了新思路。

In this paper, a new probe is proposed for the in vivo dielectric measurement of anisotropic tissue in radio frequency band, which could accomplish the dielectric measurement in perpendicular directions by one operation. The simulative studies are performed in the frequency range from 1-1 000 MHz in order to investigate the influence of probe dimension on the energy coupling and sensitivity of measurement. The suitable probe is designed and validated for the actual measurement in this frequency band. According to the simulation results, the energy coupling of the probe could be kept below -12 dB in the frequency range from 200-400 MHz with high sensitivity of measurement for the dielectric properties of anisotropic tissue. That indicates the new type of probe has the potential to achieve the dielectric measurement ofanisotropic tissue in radio frequency band and could avoid the measurement error by multi-operations in the conventional method. This new type of probe could provide a new method for the in vivo dielectric measurement of anisotropic tissue in radio frequency band.