Measurement of terahertz properties of pastes and gels used in medical examinations

Terahertz properties of materials like paste and gel used in medical examinations are measured in order to investigate their applicability to terahertz sensing probes in contact with human skin. Measured samples are cream, paste and gels used for electrocardiogram (ECG), electroencephalography (EEG), ultrasonography and so on, which have quality against skin irritation. Measurements are done with a time-domain spectroscopy system, and dielectric constants, absorption coefficients and electric conductivities are obtained for 1-2 mm thick samples packed between thin polyethylene films.