Návrh a realizace laboratorní úlohy pro měření bioimpedance

Abstract

The goal of this bachelor’s work was to explained the principle of bioimpedance measurement of the human body and elaborated a laboratory task including with the design and production works of the equipment for measuring of the bioimpedance. Verifying or compering of functions with a commercially available device. The Bioimpedance is measured using by a tetrapolar system electrodes, when one couple of electrodes is used to inject a constant electric current and the other couple of electrodes is for measuring electric voltage on one of chosen module (the human tissue or RC-component). The method of measuring consist in the fact that after placing or setting the human body in to an electric field, there is a polarization charge on the cells and the passage of electric current. Each of the cellular structure in the human tissue produce a specific electrical properties. Frequency-dependent structures are cytoplasmic membranes. The breakthrough frequency is 50 kHz. Electric current of lower frequency goes through of the extracellular fluid only, whereas frequency over then 50 kHz of electric current is enable to pierce into the intracellular fluid. Other characteristics of human tissue are differing values of resistivity. The resistivity of human bodies is from 65 to 16 600 [Ω∙cm].