Abstract:

Measurement of electrical conductivity of biotissues is used in medicine to determine their electrophysical properties. Research and analysis of such properties allows to improve surgical technologies of treatment of patients. An important property of living biotissue is the ability to polarize its constituent elements (tissue layers, cells). Undamaged cells have a high polarizing capacity. The electrical impedance of biotissues depends on the frequency of the measuring current by capacitive type. Currently, single-frequency, dual-frequency and multi-frequency impedancemetry are widely used in various fields of clinical medicine: preoperative diagnostics - to detect open and intratissue structural pathologies of small volume (including otorhinolaryngology, gynecology, frostbite, burns and others); intraoperative diagnosis - to detect tumors and determine their boundaries, reduce blood loss during surgery. To determine the impedance of biotissue, the measurement system involves the registration of current and voltage in the circuit of the electrodes. The development of impedance surgical systems is one of the areas in the development of medical systems that allow to some extent automate electrosurgical technologies. The basis of such systems is the ability to measure and analyze the impedance of biotissues. The known method of connecting soft biological tissues, which determines the parameters of heating tissues with high frequency current, namely impedance, in real time is improved by introducing an initial stage of the process, during which the bipolar electrodes are fed a series of programmable high frequency voltage pulses. The initial stage is required in order to "prepare" the welded tissue for exposure to bipolar high-frequency current. This consists in bringing the resistance of the welded tissue to values at which reliable operation of the automatic control system of the welding process is observed.

Keywords: Impedancemetry, Welding of biological tissues, electrosurgery