МАТЕМАТИЧЕСКАЯ МОДЕЛЬ ДРОБЛЕНИЯ МОЧЕВЫХ КОНКРЕМЕНТОВ В МОЧЕТОЧНИКЕ ГОЛЬМИЕВЫМ ЛИТОТРИПТЕРОМ

Abstract

Purpose: development of a mathematical model for prediction of the duration of transurethral contact holmium lithotripsy in the ureter area, which enables to estimate the duration of lithotripsy on the basis of the patient ‘s preoperative examination results. It has been found that the number of postoperative complications associated with contact laser lithotripsy depends on the duration of the concrements crushing process. Therefore, knowledge of the expected time of lithotripsy before the beginning of the operation will allow correct splicing of the operation tactics and preventive therapy in accordance with the expected duration of lithotripsy. In order to build the model, experimental measurements of the duration of the transurethral contact laser lithotripsy in vivo were carried out by the holmium lithotripter in the fragmentation of urinary concrements in the various sections of the ureter. Lithotripsy time is represented as sum of concrements crushing time (net fragmentation) and additional costs for auxiliary manipulations inevitable during lithotripsy. When estimating the expected time of «pure» crushing, the weight of the concrements, the specific value of mass loss under the influence of laser radiation and the parameters of the holmium lithotripter, in particular the energy and frequency of laser pulses, are taken into account. According to the results of experimental data, a multi-factor regulatory model was built, which allows to estimate the time of holmium lithotripsy.