An electrodeless measuring technique for determining conductivity of biological tissues at radio frequencies.

An electrodeless measuring technique for determining the conductivity of biological tissues at radio frequencies is described. The technique is based on measuring magnetic power dissipation in a conducting sample using a tuned circuit when the sample is immersed in a time-varying magnetic field. Theory regarding the measurements is presented. Consideration for coil design is given. Coil construction and measurement techniques are described in detail. The technique has three advantages: errors resulting from electrode lead inductance are completely removed; contacts between tissue surfaces and electrode surfaces are not needed; and maintaining water content and concentration of pH solution inside the tissues during measurements becomes easily facilitated. With the technique, conductivity values of dog kidney at room temperature were obtained in good agreement with previous work.