Heart Valve Project

Our team took on the challenge of creating and building a functioning model to test the qualities of heart valves without utilizing actual specimens. We used the engineering design process to investigate, create, test, and refine a prototype heart valve that resembled the structure and performance of actual heart valves.

We started by looking at the construction of heart valves, specifically the trilaminar architecture of the ventricularis and fibrosa layers. We used this knowledge to evaluate the elasticity and strength of numerous materials, including rubber bands, balloons, and plastic sheets. We examined their stress-strain behavior with a system that allowed us to compute their Young's modulus and compared the results to actual valve tissue. This data influenced our material decision, ensuring that our prototype closely resembled real valve qualities.

Then we created and produced our prototype, which had at least two layers: a rigid layer for stability and an elastic layer for flexibility and recoil. After drawing our plans, we built the model and evaluated its capacity to spring back to an open position after compression and to sustain repeated stress. Additional studies mimicked conditions similar to blood flow pressure, allowing us to evaluate its real-world performance.

Following early testing, we modified our design by varying material combinations and thicknesses to increase functionality. We optimized the prototype multiple times to better mimic the behavior of a real heart valve. Our final design proved elasticity, flexibility, and structural stability while remaining consistent with the trilaminar structure of actual valves.

We documented the entire process in a digital portfolio that included research, design sketches, test results, stress-strain graphs, and a description of our findings. This project allowed us to use engineering principles to solve a biomedical problem while also learning more about material qualities and iterative design techniques.

Images and a video of our heart valve are shown below, highlighting its components and functionality. The model shows how it opens when force is applied from one direction while remaining closed on the opposing side, replicating the function of an aortic heart valve by allowing liquid to flow only in one direction. It has three apertures that return to their original position when the applied force reduces or stops. Regular tape is used to close the openings, while duct tape acts as a sealing layer to keep water from getting past the valve.

Concepts:

Young’s Modulus: Young’s modulus measures material stiffness and is critical in selecting the right material. A high modulus meant the valve was rigid enough to close tightly, while sufficient elasticity prevented cracking. This ensured a balance between flexibility and durability.

Stress and Strain: Stress measures force per unit area, while strain measures material deformation. These concepts helped us analyze how the valve performed under pressure. By staying within the elastic region of stress-strain behavior, the valve avoided permanent damage. This analysis informed material selection and guided design improvements for durability.

Forces: Forces were key to understanding how the valve works. We calculated the pressure from fluids and the reactive forces on the material to ensure the valve could handle real-world stresses without failing. This connects to physics concepts like fluid dynamics and structural mechanics.

Valve Structure: The valve’s design had to balance strength, flexibility, and durability. It needed to open and close efficiently under repeated use without deforming. We drew inspiration from natural designs like heart valves, blending biology and engineering principles to create a reliable structure.

Elasticity: Elasticity describes how a material regains its shape after being stretched or compressed. We tested valve materials to ensure they could handle repetitive cycles without wearing out. This informed our choice of durable yet flexible materials, a concept rooted in material science.

Valve Layers: The fibrosa, spongiosa, and ventricular layers work together to form a strong, flexible, and efficient valve capable of withstanding high pressure and repeated motion. The fibrosa, as the outermost layer, is structurally strong and resists deformation. The spongiosa, located in the center, functions as a cushion, absorbing stress and allowing smooth mobility between layers. The ventricularis, the innermost layer, provides flexibility and promotes proper closure to prevent backflow. These layers work together to ensure that the valve remains durable and effective.

Reflection:

This heart valve model project had its ups and downs, but it taught me how to use critical thinking and collaboration. One of the things I did well was applying critical thinking to design and improve the valve. We spent a lot of time testing different materials and making prototypes to guarantee that the valve worked properly, opening and closing. I used collaboration well because I worked with my team and we all split our work evenly so we could work as effectively as possible. I could have worked on character and communication. Rather than trying to take on too much on my own, I understand the value of cultivating patience, trust, and teamwork within a team. This would have resulted in a more inclusive and balanced approach. As for communication, being clearer and more consistent in presenting my thoughts, as well as ensuring everyone was on the same page, would have made the process run more smoothly and efficiently. These are the areas I want to improve to be a better teammate and leader in the future.