(449cl) The Role of the Non-Newtonian Behavior of Blood in the Hemodialyzer with Cylindrical Geometry

Authors: 
Allred, A. N., Tennessee Technological University
Sanders, J. R., Tennessee Technological University
Liu, Y. W., Tennessee Technological University
Arce, P. E., Tennessee Technological University
According to the U.S. Department of Health & Human Services, every day 13 people die waiting for a kidney. Of the more than 122,000 Americans currently on the waiting list for a lifesaving organ transplant, over 101,000 need a kidney, and fewer than 17,000 people receive one each year. The United States Renal Data System states that approximately 468,000 Americans receive dialysis, and approximately 193,000 live with a functioning kidney transplant. While current dialyzers assist patients presenting with pathological kidney conditions, they fail to provide a good quality of life. An implantable artificial kidney would be ideal to allow patients to live a normal, healthy life. As a path to this artificial kidney, the micro-rheological properties of blood in the hemodialyzer are analyzed at the microscopic scale based on continuum mechanic approaches. Once the proper understanding of the microscopic behavior is attained (with the possible impact on the macroscopic scale), the system will be downscaled to a size ideal for potentially designing an artificial kidney. Due to the fact that the blood behaves as a non-Newtonian fluid as one downscales, an analysis needs to be performed to determine how the bloodâ??s microrheology will affect the mass transfer regime in the smaller-scale hemodialyzer. The analysis also involves comparing bloodâ??s non-Newtonian regime to that of a Newtonian model, along with the presentation of the hydrodynamics including the mass transfer effects. Furthermore, the analysis considers strategies with illustration of the potential impact of these non-Newtonian properties on dialyzer performance. For example, the roles of these properties in influencing the separation performance of the dialyzer under a variety of operating conditions will be considered in the development of an asymptotic (analytical) solution for the separation (cleaning) efficiency to assess the impact of the bloodâ??s Non-Newtonian behavior. Parameter bounds for the validity of this asymptotic solution will also be discussed. The future direction of the research will also be illustrated.