Enhancement of Solute Removal in a Hollow-Fiber Hemodialyzer by Mechanical Vibration

Better solute clearance, particularly of middle-molecular-weight solutes, has been associated with improved patient outcomes. However, blood-membrane interaction during dialysis results in the development of secondary mass transfer resistances on the dialyzer membrane surface. We discuss the potential effects of mechanical vibration on the diffusion, convection and adsorption of uremic solutes during dialysis. For sinusoidal and triangular vibratory motions, we conceptualized the hemodynamic changes inside the membrane and consequent effects on membrane morphology. Longitudinal vibration generates reverse flow by relative membrane motion, and transverse vibration generates a symmetric swirling flow inside the hollow fiber, which enhances wall shear stress and flow mixing. Moreover, the impulse induced by triangle wave vibration could provide higher absorption capacity to middle-molecular-weight solutes. Mechanical vibration could enhance solute removal by minimizing membrane morphology changes resulting from blood-membrane interaction during hemodialysis. These effects of mechanical vibration can be helpful in extracorporeal blood purification therapies including continuous, portable and wearable systems. Copyright (C) 2011 S. Karger AG, Basel