Heart Valve Experiment Overview

We created a synthetic replica of the human aortic valve for this experiment. In order to build the model, we started by choosing the materials based on the Young's Modulus information gathered from our previous study. We created a prototype that successfully illustrates the composition and operation of a human aortic valve using these materials. Our product consisted of latex gloves, rubber balloons, a funnel and transparent tubes. Through testing, we found that the rubber balloon could retain a higher amount of pressure than the latex meaning it was more stretchy. So we used the latex glove as the heart itself squeezing it to simulate the pumping of blood while the balloon was used as the opening of aortic valves. We took the balloon and pipe out of the original opening design in order to remodel our product. The majority of our early concepts for our foundation, which used clear pipes and a latex glove to simulate a pumping heart, were retained. When force was applied to the latex glove which acted as the heart being "pumped", the pigtail balloon attached to the funnel's bottom had a hole in it that allowed water to flow through. It was also sufficiently tight to simulate the opening and closing of a heart. After several adjustments and redesigns, our team successfully created a model that closely resembles the human aortic valve. Variations in density, blood pressure, and water pressure are examples of potential mistakes. We did not take into account the variations in these compounds' characteristics when we tested our model with water. These differences could be tested by other research.

Initial Research

Materials Testing

Each group was given the task of selecting supplies to be used in the construction of a replica heart valve. This portion of the project required us to examine each material selected and contrast its characteristics with those of actual heart valve tissues. Our group decided to use stretchy materials such as rubber balloons and latex gloves from school. The goal of our materials being tested was being able to calculate the stress and strain of each material and we were able to accomplish this by inserting variables into the equations of stress and strain. This lab write up shows all of the steps and components that went during our material testing phase which includes why we initally chose those materials we chose, how we tested them, and why we tested them. What materials have Young's modulus that is comparable to the native heart valves in humans was our main question. 

Content

Systole - Contraction phase of the heartbeat, during which the heart muscle pumps blood from the chambers into the arteries 

Aortic Semilunar Valve - Connects the heart's ventricles and arteries, with flaps shaped like a crescent moon

Elastin - Highly abundant protein in your body, is stretchy and can extend and recoil

Ventricular Layer - Composed of collagen and elastin fibers and serves as an insertion point for chordae tendineae, anchoring leaflets to papillary muscles in your heart

Laminar Flow - Type of fluid flow pattern where particles move in parallel lines

Fibrosa Layer - Cardiac aortic valve consists mostly of a dense network of type 1 collagen fibers that bear tensile loads

Aortic Valve - Primary outflow valve for the left heart, opening during ventricular contraction and closing between beats to prevent backward blood flow

Aorta - Main artery in the heart, carries oxygenated blood from the left ventricle to the body through a cane-shaped curve

The cross-sectional area - Two dimensional area obtained when a three dimensional object is sliced perpendicular to a specified axis

Ventricles - Large heart chambers that collect and expel blood received from atria, when the atrium priming the pump

Atriums - Thin walled chambers receiving blood from veins, while ventricles are thick walled chambers pumping blood out of the heart

Young's Modulus - Measure of the ability of a material to withstand lengthwise tension or compression. 

• Referred also as modulus of elasticity and is equal to the longitudinal stress divided by the strain.

Stress - Force per unit area within materials resulting from externally applied forces or other factors

Strain - Measurement of how much an object can stretch before deformation

Elasticity - Measurement of an object or variable's sensitivity to change

Leaflet -  Flap in each heart valve that opens and closes during each heartbeat, ensuring proper blood flow

Reflection

The Heart Valve Experiment tested the resilience, critical thinking, and communication skills of our group. By taking on the challenge, we were able to accomplish all of these goals. Even though it was difficult to figure out what materials to use and how to construct a prototype, we never gave up. Finally, after much research and revision, we built a prototype that met the specifications. Our group also needed to exhibit a high level of critical thinking. Applying what we currently know about the human heart to the data we collected from material testing required a great deal of work and careful consideration. Finally, there was great group communication. We decided as a group to assign tasks to each other and communicate what each person was doing. We gathered again after that and discussed our successes. This made it possible for everyone to complete their tasks and gain a greater understanding of the project, which improved its overall performance for our group. 

Throughout this assignment, staying focused and on track was one area where our group found it difficult. In between the Heart Valve Project, we also had to work on our capstone project, which added to the difficulty and stress level for all of us. In addition, our crew put off building and testing the valve from the materials, which allowed us to finish it a few days ahead of schedule. This was an inefficient use of our time management abilities. Overall, our group got along well and we are happy with the way this project turned out and the final result we produced.