RESEARCH ON HIGH-FREQUENCY VOLTAGE IMPULSES PARAMETERS IMPACT FOR BIOLOGICAL TISSUES DIELECTRIC CHARACTERISTICS IN THE ELECTRICALLY WELDED INTESTINAL ANASTOMOSIS MODEL

Abstract

Introduction. The electrical welding method for the intestinal anastomosis creating is new and promising for clinical implementation. The optimal radiofrequency parameters to tissues influence for providing their connection essentially differ between research groups' publications.

Aim: is to investigate the high frequency voltage influence, depending on its amplitude during impulsed mode, to change intestinal walls' dielectric properties in the model of welded intestinal anastomosis.

Material and methods. 120 probes of constant or growing radio-frequency voltage application to tissues from pig organs complex by 0.2 seconds impulses after pressure from 2.0 N/mm2 to 3.0 N/mm2 have applied. Organ walls doubled simulating an intestinal anastomosis in the instrument prototype.

Results. At 80 V stable, in 82.5% probes tissues impedance dropped sharply by 70% during the first impulse, while the second — smoothly by 50% additionally, and in next was stable at a low level after fluctuation at the impulse beginning. Subsequently, the voltage was raised to 120 V, and in 92.5% probes impedance level declined sharply during the first impulse by 80%, while during the second it was already generally stable. With a linear increasing voltage during the impulse from 80 V to 120 V, the electrical conductivity improved on the second pulse in 87.5% probes, where the impedance initial failure at the impulse beginning changed with exponential growth.

Conclusions. The high-frequency voltage impulses, having amplitude is exceeded tissue critical level, leads to a stable improvement in electrical conductivity of intestinal walls between the electrodes, becoming already from the second impulse. The obtained data is the basis for establishment of algorithm parameters, aimed at electrical characteristics homogenizing in the site of intestinal weld anastomosis formation.

Discussion. The impedance reducing effect during impulsed voltage supply to intestinal walls, pressed between the electrodes, and further improving the electrical conductivity is a way to ensure the uniform and deep tissue structural transformations. The impedance growth with increasing voltage can be evidenced either by the inertia of ionic systems, or by in-depth tissue transformations. Using the impulse voltage supply will limit tissues overheating as a result of embedded power lowering.