The Woodruff School

SUMMARY

Hemodialysis is a renal replacement therapy that removes waste solutes from the blood stream using concentration gradients across a membrane. In order to overcome several shortcomings and increase the waste removal rate, a new dialyzer (filter) design is proposed in this study. In the new dialyzer design, the blood concurrently flows with a sheath fluid in a micro-fluidic channel. Because the blood stream directly contacts the sheath stream, it is important to prevent blood cell migration from the blood stream to the sheath stream.

This research is intended to understand 1. the migration behavior of red blood cells and platelets in a micro-fluidic channel and 2. the effect of design variables on the change of the migration behavior, and to apply the understanding to identify the feasible design space of the proposed dialyzer. The research questions identified to be answered by this research are as following.
1.What are the conditions that retain blood cells in the blood stream when it flows with sheath fluid in a micro-fluidic channel?
2.What drives the migration of blood cells?

In order to answer those research questions, a meta-model that predicts blood cell migrations in a non-uniform suspension flow for different flow conditions and channel geometry will be created by a parametric study using Lattice Boltzmann Method (LBM) based direct numerical simulation. Then, feasible conditions that will retain blood cells in the blood stream will be identified using the meta-model. This research will also study the effect of different design parameters on the hydrodynamic part of the particle phase stress and particle phase contact stress to understand particle migration behavior.

The intellectual merit of this research lies in understanding the migration behavior in a non-uniform suspension. Also, the effect of particle phase stress and particle-particle interaction on particle migration in a suspension flow will be highlighted. This knowledge will help decide the feasibility of the proposed design and can be applied in a variety of applications for the manipulation of cells in a micro-fluidic channel.

SUBJECT:	Ph.D. Proposal Presentation

BY:	Jane Kang

TIME:	Friday, November 15, 2013, 10:00 a.m.

PLACE:	MRDC Building, 4211

TITLE:	Migration of Blood Cells in Non-uniform Suspension for a Dialyzer Design

COMMITTEE:	Dr. David Rosen, Co-Chair (ME) Dr. Cyrus Aidun, Co-Chair (ME) Dr. David Ku (ME) Dr. Richard Vuduc (CSE) Dr. Victor Breedveld (CHBE)

SUMMARY Hemodialysis is a renal replacement therapy that removes waste solutes from the blood stream using concentration gradients across a membrane. In order to overcome several shortcomings and increase the waste removal rate, a new dialyzer (filter) design is proposed in this study. In the new dialyzer design, the blood concurrently flows with a sheath fluid in a micro-fluidic channel. Because the blood stream directly contacts the sheath stream, it is important to prevent blood cell migration from the blood stream to the sheath stream. This research is intended to understand 1. the migration behavior of red blood cells and platelets in a micro-fluidic channel and 2. the effect of design variables on the change of the migration behavior, and to apply the understanding to identify the feasible design space of the proposed dialyzer. The research questions identified to be answered by this research are as following. 1.What are the conditions that retain blood cells in the blood stream when it flows with sheath fluid in a micro-fluidic channel? 2.What drives the migration of blood cells? In order to answer those research questions, a meta-model that predicts blood cell migrations in a non-uniform suspension flow for different flow conditions and channel geometry will be created by a parametric study using Lattice Boltzmann Method (LBM) based direct numerical simulation. Then, feasible conditions that will retain blood cells in the blood stream will be identified using the meta-model. This research will also study the effect of different design parameters on the hydrodynamic part of the particle phase stress and particle phase contact stress to understand particle migration behavior. The intellectual merit of this research lies in understanding the migration behavior in a non-uniform suspension. Also, the effect of particle phase stress and particle-particle interaction on particle migration in a suspension flow will be highlighted. This knowledge will help decide the feasibility of the proposed design and can be applied in a variety of applications for the manipulation of cells in a micro-fluidic channel.