Cardiovascular diseases (CVDs) are the leading causes of death globally and in Trinidad and Tobago. CVD is a general term for conditions affecting the heart or blood vessels. There are many different types of CVDs, including diseases arising due to blockage or narrowing of blood vessels throughout the body, malfunctioning heart valves, birth defects affecting heart function and irregular heart rhythms. Over the past decade, rapid technological advancements have facilitated the improvement of medical imaging capabilities and tools available for designing and testing medical devices. This, combined with the applications of physics and engineering to solve clinically relevant cardiovascular problems, has resulted in a host of new and innovative solutions for patients with CVDs.
Engineering uses fundamental concepts in physical sciences and mathematics to solve real-world problems. One branch of engineering investigates the motion of fluids — how the properties of the fluid influence the way it flows, its pressures and velocities, and how the fluid interacts with the structures around it. Current and ongoing studies are now using these concepts to provide insights into how blood flows in our body and, in so doing, improve our understanding of the development and progression of various CVDs related to blood flow. Once we understand the development and progression of a CVD, we can develop or design solutions to prevent or treat the disease.
As a Lecturer in Chemical Engineering at The University of the West Indies, my research focuses on improving the lives of patients with CVDs, particularly heart valve disease. The heart has four valves that work together to ensure unidirectional flow. In some patients, one or more of these valves may malfunction, leading to improper opening or closing. If left untreated, this may lead to heart failure. Conventional methods for treating these conditions often require open heart surgery. However, new non-invasive alternatives are now available for patients deemed too high risk for surgery. For instance, the diseased valve may be replaced with a prosthetic valve via a catheter rather than open heart surgery. While these transcatheter procedures are generally successful, some patients suffer from adverse outcomes such as leaking around or the formation of clots on the prosthetic valve.
My research, therefore, involves developing virtual models of a patient’s heart and performing computer simulations that will help alleviate these adverse outcomes. The computational simulations can address the cause of the adverse outcomes, for instance: Is it the way in which the device was inserted? Is it the design of the device? Is it a combination of device selection, device insertion, and patient anatomy? The answers to these questions can then be used to develop alternative designs for device manufacturers or implantation guidelines for clinicians.
Given the broad landscape of novel devices and intervention techniques now available for treating heart valve diseases, clinicians and surgeons are continuously facing new challenges related to the appropriate selection of devices, access routes, delivery mechanisms, etc., on a patient-specific basis. To aid this decision-making and pre-procedural planning process, I have also been developing virtual models that enable the user to simulate and test patient-specific outcomes of various intervention approaches on the computer before selecting the optimal treatment for a given patient.
Aside from heart valve research, virtual models and computational simulations can be used to provide insights into any clinically relevant problem involving blood flow and its interaction with the surrounding structures in the body. Additional work includes studies on aortic aneurysms, particularly in patients with Marfan Syndrome and aortic dissection.
The development of virtual models and computational simulations is certainly non-trivial. Replicating a complex biological system, such as the heart, on a computer requires many simplifications to the geometry and assumptions about the physics of blood flow and surrounding structures. Thus, an integral part of my work is to ensure the developed virtual models and computational simulations are validated — this means that the results obtained on the computer match those observed in the real world. This is typically done through comparisons with experimental studies and clinical data.
It is not surprising, then, that this type of work requires an army of experts and professional collaborations across various disciplines. This includes engineers (chemical, biomedical, mechanical, aerospace: basically, anyone with foundational knowledge and interest in fluid flow), computer scientists, mathematicians, biologists, physicists, radiologists, clinicians, interventionalists, surgeons, and policy-makers, with support from the industry, academia, governmental, and regulatory bodies.
Dr Shelly Singh-Gryzbon
Dr Shelly Singh-Gryzbon is a Lecturer in Chemical Engineering at The University of the West Indies. Her research involves the use of computational and experimental fluid and structural mechanics to solve clinically relevant problems.