[MUSIC] Hello, my name is Bruno and I'm doing a PhD at the INRIA Saclay in the research M3DISIM We work on the numeric modeling of the human heart. My thesis combines the numeric modeling aspects, with the physics of living systems. My team has spent the last ten years developing a heart model that takes into account all of the phenomena that are involved in the cardiac cycle, from biology and mechanics to electrophysiology. The ultimate purpose of this is to provide modeling-based predictive tools in medical applications, for instance to help cardiologists select the best possible treatment for a patient. In this simulation we use an elastic lobe within the ventricle in the colored area. My task is to develop a more accurate mechanical model for the cardiac tissue. The cardiac tissue is a mix of blood and muscle cells. A mix of fluid and solid. We want to describe the interaction between these two constituents, in particular to be able to represent the perfusion phenomenon, by which oxygen is carried by blood to the cells. So we have here a situation that is not far from what you studied in this class, but with one major difference. Fluid and solid are now both in the same domain. In classical FSI, fluid and solid are in two different domains separated by an interphase. Now, we have only one domain that holds both fluid and solid. We don't want local description of the fluid solid repartition. Instead, we consider local average. We introduce a new variable phi, that describes the volume ratio of fluid within the mix. And the solid is in proportion one minus phi. This type of coupled formulation is called poroelasticity. For example here is a calculation of the local density. Fluid and solid equations are solved in the whole domain and give us, for instance, velocity, vs and vf define at any point of omega. So here is a simulation of what could be a blood pressure wave propagation within a vessel. Fluid and solid are in two separate domains. This is a classical FSI problem. My approach has been to extend the method used here to my new configuration. So, I begin with a simple problem. We have a sponge fixed on its left and bottom sides, while the other sides are free to move. In the first stage, the water inflow comes through the left and fills the sponge, then the inflow stops and the sponge self-drains. Arrows represent the fluid velocity and color is indicative of pressure. The next step will be to integrate this into a more sophisticated heart model, like this one in which the elastic law is still used, incorporating active behavior that produces contractions. [MUSIC] Let's notice that living science is not the only field concerned by poroelasticity. The oil and gas sector has been working on this for many years to better understand what happens when oil and gas are mixed with earth and how to extract them. They developed new theories under the assumption that small deformation, which I couldn't make, as the heart deforms a lot more than rocks. This presentation terminates here, I hope you enjoyed it. For any further information here are the articles related to this job and the web page of our team and my email address. Bye. [MUSIC]