Flow optimization of ventricular catheters for shear stress-induced death of astrocytes

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, September, 2019

Bibliographic Details
Main Author: Lee, Sungkwon(Mechanical engineer)Massachusetts Institute of Technology.
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2021
Subjects:
Online Access:https://hdl.handle.net/1721.1/132739
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author Lee, Sungkwon(Mechanical engineer)Massachusetts Institute of Technology.
author2 Massachusetts Institute of Technology. Department of Mechanical Engineering.
author_facet Massachusetts Institute of Technology. Department of Mechanical Engineering.
Lee, Sungkwon(Mechanical engineer)Massachusetts Institute of Technology.
author_sort Lee, Sungkwon(Mechanical engineer)Massachusetts Institute of Technology.
collection MIT
description Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, September, 2019
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spelling mit-1721.1/1327392023-08-30T17:06:26Z Flow optimization of ventricular catheters for shear stress-induced death of astrocytes Lee, Sungkwon(Mechanical engineer)Massachusetts Institute of Technology. Massachusetts Institute of Technology. Department of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering Mechanical Engineering. Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, September, 2019 Cataloged from the PDF version of thesis. Includes bibliographical references (pages 75-81). The ventricular catheter for treatment of hydrocephalus has a low lifespan due to obstruction by brain tissue. Multiple catheter designs have been proposed, but breakthroughs have not been made yet particularly due to the lack of understanding of the obstruction mechanisms that appear to be coupled with the fluid dynamics of ventricular catheters and cerebrospinal fluid (CSF). Recent studies have shown that glial tissue, which is mainly comprised of astrocytes, is the major contributor to obstruction. Impeding glial tissue formation should then be the foremost goal of the next-generation catheter, which leaves a crucial question that has not been answered yet: How does the fluid dynamics of ventricular catheters affect glial tissue formation? Answering this question, this thesis suggests a new design objective based on in vitro microfluidic experiments on astrocytes and proposes a novel design scheme developed on a lumped-element model describing the fluid dynamics of ventricular catheters. The thesis conducted long-term in vitro microfluidic culture of astrocytes and showed that fluid shear stress inhibits astrocytes from increasing confluency and reduces their viability. In light of the result, using Computational Fluid Dynamics (CFD) simulations, we showed that the conventional geometry of ventricular catheters is vulnerable to astrocytes ingrowth. To find improved catheter geometries, we performed a numerical optimization based on a lumped-element model. We validated the lumped-element model against CFD simulations also in good agreement with the direct flow visualization we performed in the actual catheters. Apart from flow analysis, CSF was investigated, determining its range of surface tension and showing it to be shear thinning at low shear rates. Finally, we propose a new design paradigm for more robust catheters for hydrocephalus patients. by Sungkwon Lee. S.M. S.M. Massachusetts Institute of Technology, Department of Mechanical Engineering 2021-10-06T19:56:56Z 2021-10-06T19:56:56Z 2019 2019 Thesis https://hdl.handle.net/1721.1/132739 1263579857 eng MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided. http://dspace.mit.edu/handle/1721.1/7582 88 pages application/pdf Massachusetts Institute of Technology
spellingShingle Mechanical Engineering.
Lee, Sungkwon(Mechanical engineer)Massachusetts Institute of Technology.
Flow optimization of ventricular catheters for shear stress-induced death of astrocytes
title Flow optimization of ventricular catheters for shear stress-induced death of astrocytes
title_full Flow optimization of ventricular catheters for shear stress-induced death of astrocytes
title_fullStr Flow optimization of ventricular catheters for shear stress-induced death of astrocytes
title_full_unstemmed Flow optimization of ventricular catheters for shear stress-induced death of astrocytes
title_short Flow optimization of ventricular catheters for shear stress-induced death of astrocytes
title_sort flow optimization of ventricular catheters for shear stress induced death of astrocytes
topic Mechanical Engineering.
url https://hdl.handle.net/1721.1/132739
work_keys_str_mv AT leesungkwonmechanicalengineermassachusettsinstituteoftechnology flowoptimizationofventricularcathetersforshearstressinduceddeathofastrocytes