Heart Valve Model

Heart Valve Project!

For this project, we were presented with an engineering challenge that asked us to develop a model that can mimic the functioning of the aortic valve inside the heart. We had to find and test materials that act similarly to the real parts of the human heart valves, and then we had to design and build a working prototype. After we tested our products and made modifications as needed, we started working on our final model. My group and I made two different versions, but the second one better fulfilled the challenge of developing a model that can be used to test the properties of heart valves without using real specimens.

This was a three-part project, with multiple steps per part in order for us to gain a strong understanding of how the heart works and how to use the engineering design cycle. Part 1 was all about researching the heart structure, blood flow, heart valve mechanics, and valve tissue anatomy. We used this information to help us with the brainstorming process, which was one of the crucial steps in this project. Part 2 was all about understanding elasticity & Young's Modulus for tissue analysis, which was a crucial step in our designing process because this information helped us finalize the right durable materials for our model. And finally, part 3 had to do with designing and building our prototype, testing it, and then re-designing and re-building it at the end. These were the last few steps of the project, so they really helped our model succeed in the challenge.

Content:

• biomedical engineering: the application of engineering principles and design concepts to medicine and biology for healthcare purposes

• aortic valve: 1 of 4 valves that control blood flow in the heart. it separates the left ventricle from the aorta and helps keep blood flowing in the correct direction through the heart

• valve tissue: their function is to promote coordinated forward blood flow during the cardiac cycle, and they are highly organized connective tissue structures populated with dynamic cell populations

• young's modulus: a measure of the ability of a material to withstand changes in length when under lengthwise tension or compression; a measure of elasticity that is found by dividing stress over strain

• elasticity: defined by a material’s ability to return to original shape after stress is applied then removed

• stress vs. strain: stress is the amount of force applied to an object, while strain is force tending to pull or stretch something to an extreme. every material has a unique response to stress and strain. stress = force divided by cross-sectional area. strain = change in length divided by initial length

• force: strength or energy as an attribute of physical action or movement

• recoil: when the object returns back to its original shape after stress is removed

• aorta: the main artery that carries blood away from your heart to the rest of your body. the blood leaves the heart through the aortic valve and travels through the aorta

• trilaminar structure: 3 layers existing on top of one another; the aortic valve has a trilaminar structure that is made up of the ventricularis, spongiosa and fibrosa layers

• engineering design process: a common series of steps that engineers use in creating functional products and processes. 1. research the problem/topics you need to know 2. brainstorm possible solutions/ideas 3. test materials and do calculations 4. build your prototypes 5. test these models to see how they work and what needs to be changed 6. finally redesign/rebuild your model/project to perfect it

• prototype: an early sample or model of a product built to test a concept or process. we designed and built a few prototypes for this heart valve project

Reflection:

Throughout this project, I learned a ton about the engineering design cycle and how to do certain calculations like Young's Modulus to find the best materials to use for our model. My group and I had some errors in our final model that we had to fix and re-build, so we got used to the re-designing cycle that comes with the process of creating something new. Overall, I really liked this project because we were able to create something from scratch, after researching and learning about the topic of heart valves prior to the designing process. It was a true engineering experience.

That being said, there were a few things I did well at and a few things I didn't do so well at during the past few weeks. One category I excelled in was critical thinking. I did all of the Young's Modulus calculations by myself, which took a lot of critical thinking to understand how to do certain equations and what units to use, etc. I was very proud of myself for working intellectually and challenging myself with every part of that calculation assignment. Another category I was good at was creativity. My group and I had to come up with many designs and build different prototypes, so we were very creative when it came to that process. We came up with new ways to build things and how to incorporate each material into our model in order for it to function properly.

Two categories I could have improved in, however, include conscientious learning and communication. Regarding conscientious learning, we could have been much better at managing our time in class because we ended up having to finish our project at home. We turned it in on time, but we should have been more productive in class so that we wouldn't have had to worry about it outside of school. And for communication, there was one group member that wasn't here during the majority of this project, but we didn't communicate with her to let her know how she could help us at home or what we did in class so that she could be caught up, instead we just told her that information if we saw her at school a different day. We probably would've been able to finish more efficiently if we kept her in the loop when she was absent so that she could pitch in when she was at home.