Design and testing of a device for human limb multifrequency comparative bioimpedance measurement– preliminary study

Anotace: Bioimpedance is the ability of biological tissues to impede the flow of electrical current. It is often measured as a means of detecting volume and structural changes in various biological tissues. The purpose of this work was to design a two-channel portable device for measuring multifrequency bioimpedance of human limbs. The device was constructed specifically for evaluation of the bioimpedance measurement as a possible tool for aiding in diagnosis of soft-tissue structural changes in the muscles of human limbs by continuously comparing bioimpedance of one limb to the other. The proposed device is based on impedance converter AD5933. It is designed for noninvasive measurements on the human body with low amplitude alternating current at frequencies between 1 kHz and 100 kHz. The device was tested for electromagnetic compatibility, accuracy and used in laboratory measurements for detection of muscle edema on a bioimpedance model. It is capable of measuring impedance up to 100 kΩ with a relative measurement error below 1.84%.