FINITE ELEMENT ANALYSIS FOR COMPARING THE PERFORMANCE OF STRAIGHT AND UNDULATED FIBERS IN ALTERING THE FILTERING EFFICIENCY OF HEMODIALYZER MEMBRANES

Abstract

The hemodialyzer, known as “artificial kidney”, serves as an excellent tool in filtering the impurities from blood. The structure of the hemodialyzer plays a major role in separation of solutes through diffusion. The hemodialyzer module consists of thousands of hollow fibers, which actually filter the toxins such as urea and creatinine from the blood. Many of the commercially available hemodialyzer modules consist of fibers available in different configurations, viz. straight and crimped (undulated). It has been reported that fiber crimping enhances solute clearance. In crimped fibers, the waviness is dictated by two parameters, namely the crimp count and crimp amplitude. These two parameters should be optimized when inducing fiber crimps. However, excessive crimping also leads to fiber damage. In this paper, the hemodialyzer membrane is modeled which describes the structure of Fresenius Polysulfone-Hemoflow (F6HPS) in two configurations, viz. straight and crimped and finite element analysis is carried out using finite element software COMSOL multiphysics5.2a. The solute clearance is studied in straight fibers as well as crimped fibers for the same length while varying the crimp count and crimp amplitude. It has been observed that in crimped fibers, increasing the crimp count and crimp amplitude increases the clearance significantly when compared to straight fibers. While increasing the crimp count as [Formula: see text], the clearance is nearly twice that of straight fiber. This clearly shows that when developing hemodialyzers with undulations, the crimp count and crimp amplitude has to be optimized in order to get a better filtering efficiency.