Interview: Susanne Hoecht, Image: Susanne Hoecht
Janina, you studied Mechanical Engineering at both Bachelor's and Master's level. How did you decide on this course of study?
It came mostly from the medical engineering direction. After graduating high school, I did a voluntary social year at the German Heart Center in Munich. During this year, I thought about what I could do and then came across medical technology and mechanical engineering. I realized that you have many options with a mechanical engineering degree. The nice thing about studying mechanical engineering is getting a sound fundamental understanding of engineering. For example, in the first few semesters, there are courses in math, physics, chemistry and engineering mechanics. That way, you can decide later in your studies which direction and industry to go into.
You have been working as a research associate at the Chair of Computational Mechanics for three years. What is computational mechanics?
Computational mechanics is a subfield of mechanics that focuses on solving complex systems of equations in continuum mechanics numerically rather than analytically. Hence the term "computational". This is mainly because many real-world problems are too complex and extensive to be solved by hand. Computer programming can be used to deal with sophisticated systems, such as biomechanical problems. These are often super complicated because the geometry is unclear, and the underlying processes are highly complex. This is particularly true for biological materials, which often differ significantly from the behavior of synthetic materials, for example. Of course, this also applies to many other areas.
What fascinates you about computational mechanics?
I am fascinated by the wide range of possible applications of computer simulations, which allow me to gain new insights and try out things that would otherwise not be possible. For example, crash tests are carried out in the automotive sector, and flow simulations are used in the wind power industry. Such simulations are particularly valuable in areas such as medicine, where experiments cannot simply be carried out.
At the Chair of Computational Mechanics, under the direction of Professor Wall, much research is carried out on biomechanics. I was already fascinated by this focus during my studies, especially when I learned that simulations of the heart are also carried out there. As a result, I increasingly specialized in this field during my studies and wrote both my Bachelor's and Master's thesis in this area. Especially when the opportunity arose for a joint PhD project with the German Heart Center. I was already familiar with the center, so I couldn't say no to this collaborative project.
What research topic are you working on, and what is the project about?
Our focus is specifically on the numerical simulation of coronary angioplasty. In this treatment method, often used for narrowed coronary arteries, a stent is inserted to restore blood flow and supply the heart with sufficient oxygen. We aim to model and analyze this complex process using computer simulations.
How does the research project contribute to new findings in medicine and cardiology?
The fundamental question of my project deals with the observation that around ten percent of patients who undergo coronary angioplasty have a new narrowing in the treated vessel, which represents a new, non-identical disease. This observation suggests the hypothesis that using a stent stimulates growth processes that can lead to re-narrowing of the vessel. This phenomenon is a mechanical problem in which the stent triggers local changes that lead to a new disease. Current medical approaches tend to treat this disease systemically by taking into account risk factors such as age and smoking status and prescribing appropriate medication. However, the problem is exceptionally localized and varies significantly from patient to patient and from treated vessel to treated vessel. This means that if several stents are inserted in the same patient, often, restenosis occurs with one stent and not with another. Therefore, we aim to better understand this process, which was previously not possible using standard imaging procedures. We use patient-specific simulations using medical image data such as CT images to create individual models and adapt the simulations accordingly.
Why do you particularly like the topic?
I like the topic because it is interdisciplinary and the underlying problem is a great motivation. Coronary heart disease is frequent worldwide and is one of the leading causes of death. Of course, there is already much research in this area, which is also intimidating. But technological progress also opens up many opportunities to shed light on the topic in a different way. With computer simulation studies in particular, it is now possible to make relevant statements. For example, computer tomography images now have such high resolution that a detailed and accurate vascular model can be created in the simulation. This was not possible before. Also advances in image processing, for example in image segmentation, have made the work easier. This used to take a lot of time and effort, but now it's much more manageable.
At the chair, we develop various methods for numerical simulations, from theoretical to applied. My project builds on the work of previous researchers and uses, for example, a beam model for the stents and novel algorithms for contact mechanics. None of this would have been possible a few years ago, but now we can make significant progress and understand what is happening. It's motivating to see how it all comes together and works.
As a final question, what findings have surprised you so far in the project?
Recently, I have been working more intensively with image data from a more significant number of patients. As an engineer, I was surprised by the diversity of the data. The angiography data and X-ray images taken during stent placement were fascinating. They show the course of the procedure and the changes in the vessel before, during, and after stent placement. This data illustrates the complexity of the process, which is different for every patient. Pre-stenting with a balloon is often carried out before the stent is inserted. Sometimes, this dilation is also done afterward. I thought this process would be much more standardized. But the reality is that it works differently for every patient. This has changed my view of my research. It underlines the importance of a patient- and lesion-specific approach. The diversity of vascular structures and the individual reactions to the procedure show no standard solution. Understanding the relationship between vessel characteristics and clinical outcomes is essential. These findings are astonishing and motivate me in my research project.
Thank you very much for your time, Janina.
Profile of Janina Datz: https://www.epc.ed.tum.de/lnm/staff/janina-datz/
Research at the Chair of Computational Mechanics: https://www.epc.ed.tum.de/lnm/research/