Bioimpedance Spectroscopy for the Postmastectomy Lymphedema Diagnostics

In this paper, an approach for diagnostics and stage estimation of the postmastectomy lymphedema of the upper limb is presented. Our method is based on segmental bioimpedance spectroscopy of patients’ upper limbs. With this method measurements of the impedance amplitudes and phases are done in the beta-dispersion frequency range of biological tissues, from 1 kHz to 1 MHz. Cole equivalent electrical model for biological bodies is used to determine the electrical resistances of the cellular and extracellular liquid compartment. These values are further combined with Hanai emulsion model of dielectric particles in the conductive liquid was used to derive the ratios of the volumes of the cellular and extracellular liquids. Comparison of the estimated properties between the affected and unaffected limbs or changes of these properties in the affected limb over time is summed up by the lymphedema index. This index reflects the proportions of liquid compartment volumes ratios. We also present results of a preliminary study on volunteers for the viability testing of the method. We compare the lymphedema indexes of the healthy female subject and female subject with diagnosed second stage lymphedema after mastectomy.