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- Gårdhagen, Roland, et al.
(författare)
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Wall Shear Stress in Turbulent Pipe Flow
- 2009
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Ingår i: Proceedings of the ASME Summer Bioengineering Conference 2009. - 9780791848913 ; , s. 963-964
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Konferensbidrag (refereegranskat)abstract
- Low and/or oscillatory Wall Shear Stress (WSS) has been correlated with elevated risk for increased intima media thickness and atherosclerosis in several studies during the last decades [1, 2]. Most of the studies have addressed laminar flows, in which the oscillations mainly are due to the pulsating nature of blood flow. Turbulent flows however show significant spatial and temporal fluctuations although the mean flow is steady.
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| 2. |
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| 3. |
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| 4. |
- Shum, Judy, et al.
(författare)
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Quantitative assessment of abdominal aortic aneurysm geometry and rupture potential
- 2009
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Ingår i: PROCEEDINGS OF THE ASME SUMMER BIOENGINEERING CONFERENCE - 2009, PT A AND B. - 9780791848913 ; , s. 1303-1304
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Konferensbidrag (refereegranskat)abstract
- Recent biomechanics studies have shown that the maximum transverse diameter of an abdominal aortic aneurysm (AAA) and its expansion rate are not reliable indicators of rupture potential. We hypothesize that geometrical shape and size, as well as wall thickness may be related to rupture risk and can therefore be deciding factors in the clinical management of the disease. A non-invasive, image-based evaluation of AAA size and geometry was implemented on a retrospective study of twenty subjects. The contrast enhanced, computed tomography (CT) scans of 10 patients who suffered AAA rupture within 1 month of the scan were compared to those of 10 patients who received elective repair. The images were segmented and three-dimensional models were generated. Twenty-eight geometry-based indices were calculated to characterize the size and shape of each AAA and regional variations in wall thickness were estimated. A multivariate analysis of variance was performed for all indices comparing the ruptured and non-ruptured data sets to determine which indices are statistically significant. Receiving Operating Characteristic (ROC) curves were generated to determine the indices' potential as predictors of rupture risk. In addition to maximum diameter, five other geometry-based indices were found to be statistically significant, with the minimum wall thickness being the best discriminator between ruptures and non-ruptured AAAs.
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| 5. |
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| 6. |
- Watton, P. N., et al.
(författare)
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Coupling the haemodynamic environment to the evolution of cerebral aneurysms
- 2009
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Ingår i: Proceedings of the ASME 2009 Summer Bioengineering Conference, Parts A and B. - : ASME Press. - 9780791848913 ; , s. 161-162
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Konferensbidrag (refereegranskat)abstract
- Cerebral aneurysms are thought to be present in 2–5% of the general population. Most aneurysms remain asymptomatic and of those that are detected, the risk of rupture is relatively low, i.e. 0.1–1% per year. However, very high morbidity and mortality rates are associated with an aneurysm that does rupture (30–50%). Consequently, elective repair of an aneurysm at high risk of rupture may be deemed appropriate. Unfortunately, interventional procedures are themselves not without risk and have morbidity rates of up to 6%. Moreover, it is difficult to quantify the risk of rupture on a patient specific basis: more sophisticated diagnostic criteria are required. Computational models of aneurysm evolution aim to improve the understanding of the aetiology of the disease. The ultimate aim is to predict future evolution and rupture.
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