MIT Libraries logoDSpace@MIT

MIT
View Item 
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Graduate Theses
  • View Item
  • DSpace@MIT Home
  • MIT Libraries
  • MIT Theses
  • Graduate Theses
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

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

Author(s)
Lee, Sungkwon(Mechanical engineer)Massachusetts Institute of Technology.
Thumbnail
Download1263579857-MIT.pdf (8.769Mb)
Other Contributors
Massachusetts Institute of Technology. Department of Mechanical Engineering.
Terms of use
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
Metadata
Show full item record
Abstract
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.
Description
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).
 
Date issued
2019
URI
https://hdl.handle.net/1721.1/132739
Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Publisher
Massachusetts Institute of Technology
Keywords
Mechanical Engineering.

Collections
  • Graduate Theses

Browse

All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

Login

Statistics

OA StatisticsStatistics by CountryStatistics by Department
MIT Libraries
PrivacyPermissionsAccessibilityContact us
MIT
Content created by the MIT Libraries, CC BY-NC unless otherwise noted. Notify us about copyright concerns.