Gloeckner, Dorothy Claire
(2003)
Tissue Biomechanics of the Urinary Bladder Wall.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
The urinary bladder stores urine and permits proper micturition, both functions that are inherently mechanical. Bladder research to date has been limited to whole-organ testing and simple uniaxial study, both of which are inadequate for comprehensive modeling and rigorous analysis of the mechanical properties of the bladder wall. In this work, we studied the quasi-static and time-dependent properties of the bladder wall to further understand bladder function. To obtain the requisite multiaxial data we utilized biaxial testing techniques, which allow for a more realistic physiological loading state. The goal of the study was to develop a comprehensive understanding of bladder wall biomechanics to provide insight into tissue-level bladder function. This information can be compared against other ongoing and future studies of pathologies to aid in the design of clinical treatments. The results indicated that bladder tissue 10 days after spinal cord injury was more compliant than normal bladder when referenced to the preconditioned state. However, the preconditioned state itself was different between normal and spinal-cord-injured groups, indicating large rapid changes in structure. There was a fundamental change in material behavior after spinal cord injury that indicates structural rearrangement on a microstructural fiber level. Unlike other soft tissues, there was no difference in mechanical response over three orders of magnitude of loading strain rate, most likely due to the large range of bladder function, including fast emptying and very slow filling. The time-dependent stress relaxation tests indicated that bladder behavior was dependent on stress level, with less relaxation occurring at higher stress levels. This may be because the massive structural rearrangements during normal function cause more collagen to bear load at higher stress levels as protection from over distention. This study provided the first mechanically rigorous information regarding the tissue properties of the normal bladder wall, including comparisons to a diseased state. This information can be used to understand how differences in structure caused by disease alter the tissue behavior, and hence the biological function, of the urinary bladder.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
| Creators | Email | Pitt Username | ORCID  |
|---|
| Gloeckner, Dorothy Claire | dcgst11@pitt.edu | DCGST11 | |
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| ETD Committee: |
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| Date: |
8 May 2003 |
| Date Type: |
Completion |
| Defense Date: |
22 January 2003 |
| Approval Date: |
8 May 2003 |
| Submission Date: |
14 April 2003 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Bioengineering |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
constitutive modeling; quasi-linear viscoelasticity; spinal cord injury; anisotropy; biaxial testing |
| Other ID: |
http://etd.library.pitt.edu:80/ETD/available/etd-04142003-092041/, etd-04142003-092041 |
| Date Deposited: |
10 Nov 2011 19:37 |
| Last Modified: |
15 Nov 2016 13:40 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/7134 |
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