By Victor Zendejas Lopez and Richard Didham

How Does Cardiovascular Simulation Help Doctors?
Cardiovascular simulation gives doctors critical information related to the functionality of a patient’s cardiovascular system, and what treatment strategy will work best for that patient. When a doctor looks at a MRI or CT scan of a patient, they don’t receive very much functional information regarding the complex fluid flow through that person’s heart or vessels. As a result, there is a lot of “guesswork” involved in treating patients with cardiovascular problems. Doctors will asses the situation with limited information and make a prediction about how the human body will react to various treatment strategies. The problem with this approach is that it does not accurately capture the complexity of the human body and the diversity of the human population. Cardiovascular simulation addresses this issue by giving doctors significantly more patient specific information on what is happening in a patient’s body and in turn, allows doctors to create more effective treatment protocols.How Does Shadden Simulate the Cardiovascular System?
Finite Element analysis is a tool used by scientists and engineers to model and simulate complex systems such as modeling drag over an airplane or predict how a building will behave during an earthquake. With advances in modern computing, tools such as finite element analysis have become more powerful and are now able to analyze more complicated systems-such as the human cardiovascular system. Imagine the plumbing in your home. You have water flowing through a pipe at a steady rate, we can readily find direct relationships in this system such as the velocity of the fluid and pressure. The reason we can readily do this is because we have straight and constant geometry. Now imagine the cardiovascular system where the vessel walls are now longer rigid and there are drastic changes in vessel diameter from one section to the next. This renders the process of finding relationships between the fluid flow and pressures more difficult. The simulations conducted by the Shadden Lab begin with a snapshot of a patient’s cardiovascular system via an MRI or CT scan. From this scan, researchers create a 3D image and a finite element model is built. From this model, conditions are specified throughout the region such as wall deformability how much blood is pumped into the system. From specifying these conditions we can determine relationships between blood pressure and blood flow at different regions within the cardiovascular system.
How Accurate is Cardiovascular Simulation?
While Shadden’s simulation research shows a lot of promise, there are a few hurdles that must be overcome before this research is ready to be applied in a clinical setting. Ultimately, these hurdles are due to a lack of data available to researchers simulating the human body. Since Shadden’s Lab can’t easily measure pressure or fluid velocity within the cardiovascular system, it is difficult to validate the pressure and fluid velocity that their simulations predict. This problem with accuracy also creates another issue when it comes to tuning simulations for specific patients. There is an incredible amount of diversity within the human population when it comes to the human cardiovascular system. Depending on factors such as age, genetics and lifestyle, different people may have stiffer vessel walls, or may have higher blood flow rates than others even though their arteries could look exactly the same in a MRI scan. As a result, Shadden must make educated guesses about how to tune his simulation techniques to account for diverse body types.
Shadden Lab: Diagnosing cardiovascular disease via simulation was originally published in Berkeley Master of Engineering on Medium, where people are continuing the conversation by highlighting and responding to this story.