Optimization and mathematical simulation of transpedicular fixator

Abstract

This article describes a method of optimum design of transpedicular fixator on the basis of system analysis, probabilistic approach of reliability theory, and mathematical simulation. Stress–strain model of fixator is presented by statistically indeterminate rod system. Statistic and dynamic impacts of loads are considered caused by movements during rehabilitation. Force method is used for evaluation of static indeterminability of fixator system. Dynamic impact of load is taken into account by coefficients of dynamicity based on condition of energy equality of initial and reduced systems. Fixator design is optimized for each anthropometric group of patients. Target function for rod system is arranged with consideration for efficiency criteria. External diameter of tubular rod is taken as controllable variable on the basis of preset ratio of internal to external diameters. Fixator reliability is estimated by probability of ultimate state of each three structural elements of the fixator.