Development of a Biological Tissue Relaxation Frequency Analyzer During Electrosurgical Action

One of the methods of reducing thermal damage to biological tissues (BT) is continuous temperature control in the electrosurgical treatment area. Existing temperature measuring devices do not have high measurement speed and give information only about temperature surface distribution. To implement it, an original fast algorithm has been proposed to calculate the relaxation frequency of the BT as an indirect parameter for temperature estimation. This algorithm is based on analyzing of signals of active and reactive power emitting in biological tissues during surgery. A circuit was developed for the hardware implementation of the analyzer of the relaxation frequency of biological tissues for harmonic and polyharmonic influencing signals. The main factors influencing the accuracy and duration of transients are determined. The related parameters of the analyzer elements are investigated using numerical modeling of its operation and their values are proposed for a given level of acceptable error and duration of the transient process.