JST Paris Office

Ryo Torii - You have been conducting research work in the United Kingdom for a long time. What made you decide to carry out research work overseas?

It has been about 10 years since I came to the UK. I was not really conscious of making a decision to conduct research “overseas” right from the start. Rather, immediately after I received my doctoral degree, I worked at Rice University in the United States for about three months for a collaborative research, at the recommendation of Professor Marie Oshima from the University of Tokyo. Thinking back, the experience in the US may have propelled me to pursue my career overseas. Thereafter, I was offered a postdoctoral fellow position at Imperial College London.

Fortunately, my supervisor at the time gave me many opportunities to collaborate with various researchers in the field of medicine, and I was able to gradually build up a network through further recommendations to other collaborative partners. Today, I work with researchers in various countries including Japan and Europe, as well as the United States, Egypt, and Singapore. London serves as a hub in this sense and collaborative research relationships can expand dynamically here – this is one of the points that I find interesting about conducting research overseas.

- Could you tell us about the background that lead to your work in the current field of specialization, and your research interest in biomechanics?

Main focus of my research is mechanobiological response of living systems, known as “remodeling,” a process through which the body changes itself and adapts naturally in response to forces applied over a long period. In particular, I am interested in the remodeling of the cardiovascular system. A typical example is blood flow in the aorta of patients with heart valve diseases. Blood flows in the form of a jet within the aorta of patients with heart valves that cannot open properly due to calcification. This is similar to the jet of water that emerges forcefully when we pinch the end of a hose while watering a garden. We examined a patient’s tissue, based on a hypothesis that the jet applies repetitive and excessive mechanical burden on the blood vessel walls where it impacts, and we found that this portion of the wall had become very thin, and that the tissue had been weakened. This is an example where remodeling is functioning negatively for the body. One of my research themes is to investigate how this problem can be resolved through valve replacement surgery, as well as whether a specific type of valve should be used for particular patients for better outcomes.

Here, it is my job to quantify, through computer simulation, how much mechanical force is applied at the area where remodeling is occurring. I conduct such analysis on the aorta and the coronary artery, but my goal in the future is to provide a system that can predict changes in the blood flow when the anatomy of the patient’s blood vessel is altered by surgical and/or intravascular interventions, and thereby having it help doctors making their decisions. Along a similar thread of research, I am also involved in the development of medical devices. For example, I play a part in development work aimed at optimising the shape of artificial heart valves by predicting, through computer simulation, how blood flow changes after surgery if the shape of the artificial heart valve and stiffness of the valve are changed.

In computational mechanics, any kind of physics, such as solids, fluids, and/or electromagnetics, can be handled as long as we know the equations to be solved. This means that computer simulations on vast variety of subjects are possible but we need to face different issues and challenges specific to the subject. The cardiovascular system is a complex and integrated system of multiphysics and biology. When I first started working on biomechanical research as a student, the number of physics dealt in computer simulations were still limited. I had originally been attracted to this field of research by the challenge of doing something that was still unknown and unexplored, and I think that this has led me to my current work in an area bordering engineering and physiology.

- When carrying out your work in this field of interdisciplinary research how do you cooperate with researchers in other fields?

Close communication with doctors and medical practitioners in the field is essential in my research. I think that this is what makes it interesting for me. University College London is located close to several hospitals, and has strong research partnerships with them. Furthermore, the university has set forth policies for promoting interdisciplinary collaborations. The research environment here is ideal for engaging in dialogues with research collaborators in various disciplines, and I am very grateful for that. Whilst working in such a multidisciplinary environment, I also feel that it is very important to have a strong specialisation, which is in my case fluid mechanics and the development of numerical methods behind computer simulations. For example, when I look at medical images, my specialist experience in computational mechanics often gives me ideas on how to extract new information. While it might not be very easy to establish communication channels with the clinical community, once you have gained their trust, they will conversely introduce more and more people to you. We have established good relationships with a mutual respect for the differences in our respective fields of specialisation in engineering and medicine, and there are many researchers, even among those who are highly renowned, who take an open approach and attitude toward learning from others outside of their own fields of specialisation. This makes it easy for me to carry out my research work.

- What are your thoughts on the future outlook for your research?

There are many excellent technologies and a build-up of experience in the field of computational mechanics, and I think that my strongest desire now is to facilitate further clinical application of these. Fortunately, I am blessed with many opportunities to interact directly with clinicians, and my research outputs have been utlised by clinicians even though at the level of basic science research. Taking this one step further, I would like to develop my research for clinical use. In fact, I had once been told by a former supervisor, “After looking at your data, I am considering changing my surgical technique.” It is rewarding to receive such feedback. Going forward, I aim to contribute even more in the field of clinical medicine, which will eventually contribute to our society in wider context. I also hope to be able to contribute to the further revitalization of interdisciplinary study in biomedicine and computational mechanics.