Numerical Model to Predict Hemolysis and Transport in a Membrane-Based Microfluidic Device

Abstract

AbstractMicrofluidic devices may overcome the limitations of conventional hemodialysis and oxygenation technology to improve patient outcomes. Namely, the small form of this technology and parallel development of highly permeable membranes may facilitate the development of portable, low-volume, and efficient alternatives to conventional membrane-based equipment. However, the characteristically small dimensions of these devices may also inhibit transport and may also induce flow-mediated nonphysiologic shear stresses that may damage red blood cells (RBCs). In vitro testing is commonly used to quantify these phenomenon, but is costly and only characterizes bulk device performance. Here we developed a computational model that predicts the blood damage and solute transport for an abitrary microfluidic geometry. We challenged the predictiveness of the model with three geometric variants of a prototype design and validated hemolysis predictions with in vitro blood damge of prototype devices in a recirculating loop. We found that six of the nine tested damage models statistically agree with the experimental data for at least one geometric variant. Additionally, we found that one geometrical variant, the herringbone design, improved toxin (urea) transport to the dialysate by 38% in silico at the expense of a 50% increase in hemolysis. Our work demonstrates that computational modeling may supplement in vitro testing of prototype microdialyzer/micro-oxygenators to expedite the design optimization of these devices. Furthermore, the low device-induced blood damage measured in our study at physiologically relevant flow rates is promising for the future development of microfluidic dialyzers and oxygenators.