Motion of bacteria and CaOx particles via urine flow modulated by the electro-osmosis

Abstract

Kidney stones and Escherichia coli bacterial particles are mineral aggregates found inside the kidney and bladder that cause urinary tract infections and complications during urination. Therefore, it is essential to understand that how such stones create the obstruction in the urine flow and what are the possible solutions to remove them from the urinary system? In view of the complications in the urinary system due to bacteria and CaOx, the major objectives of this study are to investigate (a) how electro-osmosis modulates the urine flow and helps in the removal of CaOx particles and bacteria via urine flow and (b) how diameter and density of the particles will affect the motion of the particles via urine flow? An electrolyte solution with Newtonian model for the urine and a moving wavy channel with time and axial displacement for urinary track are considered. Basset–Boussinesq–Oseen equation is employed to analyze the motion of CaOx and bacteria. Poisson–Boltzmann equation is considered to examine the distribution of the electric potential in urine. Analytical solutions are derived under the suitable assumptions and suitable boundary conditions for the present biophysical model. The results showed that (a) backward motion of bacterial particles was observed via urine flow and (b) the large size of CaOx particle covers fewer trajectories with slower velocity through urine flow, which may be the reasons of obstructions/infections in the urine flow. It is further concluded that the axial electric field increases the trajectory and velocity of the CaOx particle and bacterial particles, which will help in proper functioning of the urine flow and in the removal of such particles.