Page 3 - Week 3

April 15, 2015

This week we further continued our research for how the heart functions and the different tasks that it performs. There are three different types of heart valves, the first is the mitral valve. The mitral valve closes off the upper right chamber (or atrium) that holds blood coming in from the body, opens to allow blood to flow from the top right chamber to the lower right chamber (or from right atrium to right ventricle), and prevents the back flow of blood from the ventricle to the atrium when blood is pumped out of the ventricle. The pulmonary valve whose functions is to close off the lower right chamber (or right ventricle) opens to allow blood to be pumped from the heart to the lungs (through the pulmonary artery) where it will receive oxygen. The mitral valve and its functions are to close off the upper left chamber (or left atrium) and to collect the oxygen-rich blood coming in from the lungs. The last valve and its functions is the aortic valve and it closes off the lower left chamber that holds the oxygen-rich blood before it is pumped out to the body and opens to allow blood to leave the heart (from the left ventricle to the aorta and on to the body).

We chose to do the aortic valve because it is the largest of all of the valves and would make designing and building the valve easier. This week we started designing the valve in Creo Parametric, to aid in our design we found a website that clearly lists the dimensions for common heart valve replacements. Currently the external diameter of the base will be 24 mm and the inner diameter will be 18mm so the base will be a 6mm thick circle. After settling on that we are currently trying to figure how to set up the flaps of the heart of valve replacement so that it will cut off blood flow. We are looking to have the design done by Week 5 so we can thoroughly test it and improve it for 2 weeks then send it to be 3D printed by Week 7.

In addition we changed our original design that was based off of a washer basket to that of a more simplistic and practical design, which you can see below from the screenshots of Creo Parametric. Right now, we are in the process of deciding between the rectangular and triangular openings.

Front View of Parametric Design I

Side View of Parametric Design I

Side View of Parametric Design II

Front View of Parametric Design II

Sources:

[1] Heart.org, 'Roles of Your Four Heart Valves', 2015. [Online]. Available: http://www.heart.org/HEARTORG/Conditions/More/HeartValveProblemsandDisease/Roles-of-Your-Four-Heart-Valves_UCM_450344_Article.jsp. [Accessed: 22- Apr- 2015].

[2]The Aortic Heart Valve Guide: Measurements that Affect Valve Selection, 1st ed. 2015.