Application of Reproducible Measurements of Complex Permittivities to Crystalline Lens From 500 MHz to 50 GHz

Most of fundamental biological tissues and organs, such as skin, muscle, and brain, are wet and solid. Water evaporation on the sample surfaces generally deteriorates the measurement of complex permittivities, especially in quasi-millimeter wave and millimeter wave bands. This letter, therefore, introduces a new sample preparation procedure for avoiding the water-evaporation effect. This method is first validated with liquid biological tissue, i.e., whole blood, and then applied to a wet and solid biological tissue, i.e., crystalline lenses. The results show that the new method enables reproducible measurements of the complex permittivities of wet and solid biological samples.