Aimoto A, Matsumoto T
Department of Biomedical Engineering, School of Medicine, Tokai University, Kanagawa, Japan.
Med Eng Phys. 1996 Dec;18(8):641-6. doi: 10.1016/s1350-4533(96)00026-4.
A new noninvasive method of measuring the structure and the electrical properties of bilayered biological tissues was evaluated as a potentially useful diagnostic means for detecting changes in subcutaneous tissues. First, the input impedance of an open-ended coaxial probe radiating into a bilayered model was calculated using a full-wave method, the results showed that the evanescent higher order modes do not have a significant influence on the reflection coefficient of muscle layer surface. Then, it was clearly proven that the phase shift and the modulus of the reflection coefficient of muscle layer surface depending on the frequency are useful to estimate the thickness of fat layer and the electrical properties of muscle respectively. The experimental results showed an excellent agreement with the theoretical relationship between the phase shift and the thickness. The sensitivity of estimation of the electrical properties of muscle was shown to be not enough for differentiating between normal and diseased deep tissue because of noises from the experimental systems.
一种用于测量双层生物组织结构和电学特性的新型非侵入性方法被评估为一种检测皮下组织变化的潜在有用诊断手段。首先，使用全波方法计算了辐射到双层模型中的开放式同轴探头的输入阻抗，结果表明消逝高阶模对肌肉层表面的反射系数没有显著影响。然后，清楚地证明了肌肉层表面反射系数的相移和模量分别取决于频率，这对于估计脂肪层厚度和肌肉的电学特性是有用的。实验结果与相移和厚度之间的理论关系显示出极好的一致性。由于实验系统产生的噪声，肌肉电学特性估计的灵敏度对于区分正常和患病深部组织来说还不够。
