Development of test fixture for measurement of dielectric properties and its verification using animal tissues

The electromagnetic compatibility of implantable or wearable medical devices has often been evaluated using human phantoms to electrically mimic biological tissues. However, no currently existing test fixture can measure the electrical characteristics of gel-like materials. In this paper, we report the development of a new test fixture that consists of a coaxial tube whose outer conductor is divided along the axial direction into two sections, which facilitates filling and removal of gel-like materials in order to measure their electrical characteristics. Using this test fixture, we measured the electrical characteristics of a cow's muscular tissues up to 1 h post-mortem; these measurements allowed us to obtain the relative permittivity and conductivity of the biological tissue, which should help to enable the design of new human phantoms.