Estimating abdominal aortic aneurysm wall stress in the clinic, Invited Talk from Karol Miller
Director of Intelligent Systems for Medicine Laboratory, The University of Western Australia,
Visiting Professor, University of Luxembourg,
Honorary Distinguished Professor, School of Engineering, Cardiff University
This talk took place on 11 June at 13:30 in MZH 5300 at the University of Bremen
Mathematical modelling and computer simulation have proved tremendously successful in engineering. One of the greatest challenges for mechanists is to extend the success of computational mechanics to fields outside traditional engineering, in particular to biology, biomedical sciences, and medicine. In this lecture, Dr. Miller will demonstrate how computational mechanics can be used to improve abdominal aortic aneurysm (AAA) rupture risk prediction. Abdominal aortic aneurysm (AAA) is a permanent and irreversible dilation of the lower region of the aorta. It is a symptomless condition that if left untreated can expand to the point of rupture. Mechanically-speaking, rupture of an artery occurs when the local wall stress exceeds the local wall strength. It is therefore desirable to be able to non-invasively estimate the AAA wall stress for a given patient, quickly and reliably.
Dr. Miller will present an entirely new approach to computing the wall tension (i.e. the stress resultant equal to the integral of the stresses tangent to the wall over the wall thickness) within an AAA that relies on trivial linear elastic finite element computations, which can be performed instantaneously in the clinical environment on the simplest computing hardware. As an input to our calculations we only use information readily available in the clinic: the shape of the aneurysm in-vivo, as seen on a computed tomography (CT) scan, and blood pressure.
Using magnetic resonance (MR) images of the same patient, we can approximately measure the local wall thickness and calculate the local wall stress. What is truly exciting about this simple approach is that one does not need any information on material parameters, which represents a tremendous advancement in patient-specific modelling (PSM) where uncertainty in material data is recognized as a key limitation.
The methods demonstrated in this lecture are applicable to many other areas of biomechanics where the loads and loaded geometry of the system are known.
Karol Miller studied Applied Mechanics and received a PhD in Robotics from Warsaw University of Technology in 1994, and Doctorate of Science (Habilitation) in Biomechanics from the Polish Academy of Sciences in 2003. In 2002 he established the Intelligent Systems for Medicine Laboratory at the University of Western Australia. ISML’s mission is to work towards improving clinical outcomes through appropriate use of technology. It runs exciting research projects funded by the Australian Research Council, the National Health and Medical Research Council (Australia), the National Institute of Health (USA) and other national and international agencies. The overall objective of his research is to help creating methods and tools which will enable a new exciting era of personalised medicine. He is best known for his work on biomechanics of soft tissues. His current research interests include computational biomechanics for medicine and numerical methods, with applications to surgical simulation, image-guided surgery and, surprise, geomechanics. His research and teaching have been recognised by multiple awards, including the NVIDIA GPU Computing Champion Award, the Simulation Industry Association Australia Award, the Sir Charles Julius Award, the Polish Prime Minister Award, the UWA Faculty of Engineering Computing and Mathematics Teaching Award and the UWA Student Guild Choice Award.