Week 9

Week 9

In week 9 the group faced a huge problem when they realized the 3D prints did not turn out the way they were supposed to based off the design. This is because they were designed too small. All week we tried to figure out ways to fix the problem but it wasn't until last minute that we found someone to 3D print our parts for us. 

Also in week 9, we worked on our presentation and updated our final report for the last lab.

The fluid dynamic software was also used to finish testing the valve. The results from these tests were good. We found out that the blood flow is central which is helpful to prevent coagulation. Other then last minute changes week 9 was just prep for the presentation.

Week 8

Week 8

In week 8, two weeks ahead from the Final Report, we were so busy to prepare for everything for the Presentation.

-         We submitted the 3D-printer with the scale that fits the Prototype.

-         We were discussing for the Presentation in week 10. Coming up with problems 

like: who is responsible for each parts, who will compose the PowerPoint and its design, how suite we should wear, and which questions will come up in the Q&A part at the end of the presentation.

-         Also, this week is the 2^nd Evaluation Assessment for group members. Undoubtedly, we have worked so well together, so we feel no problem with this part.

-         One more thing that very important for the Presentation, we have been doing the Analysis of the Stress and Strength of our Artificial Heart Valve design, as well as figure out the Blood Flow Rate go through the Man-made heart valves.  

Week 7

The groups final report draft was due this week so a lot of time and effort was put into making the final report optimal. The group afterwards realized they were confused on how to correctly cite the references used. To fix this issue time was spent to learn the proper IEEE citation format.

The group also waited for the 3-D printing parts to be printed out so they could be assembled. While they waited the group tried starting the presentation while downloading and learning how to use the CFX ANSYS effectively.

Week 7 was definitely a week here the group while waiting decided to outline how exactly we would finish up the final details of the project.

Week 6

During week 6, group 12 started to prepare for the end of the term. 

This week we finished the hinges on both the ring and the leaflets. Thankfully, our hinge design was successful and we were finally able to assemble the artificial valve. The model was sent to the 3D printer.

We also learned more about the Ansys CFX program that we will use to analyse the movement of blood through the valve.

Source:
http://www.ansys.com/staticassets/ANSYS/staticassets/resourcelibrary/brochure/fluid-dynamics-brochure.pdf

Finally, we started to work on our final presentation and report.

Week 5

During this week, we decided to redesign the hinges of our artificial heart valve. Hopefully, the tests that we will be performing on our valve design prove to us that we made the right decision. Currently we have worked on our 3D model using Creo Parametrics and are almost done with our 3D design.

New idea for design of hinge

Designing with CreoParametrics

"Ring" of the Artificial Heart Valve 

"Leaflet" of the Artificial Heart Valve 

Once we are finished, we will test the design using ANYS CFX (Computational Fluid Analysis) and then we will 3D print it. After having the prototype ready (which will be scaled 3 times the original size), we are planning to test it using PVC tubes and a fluid with a density similar to water.

Wish us good luck during this week!

Week 4

Working with Creo Parametric

This week, we spent time working with the project based on our timeline.

1       We researched and discussed to come up with the design for our tri-leaflet heart valve.

     We also met with each other outside the class to group-study for how to combine the mechanical tri-leaflet heart valves with the non-invasive surgery model. Here is what we figured out after research and discussion:

      

      

      It took a lot of time for us to figure out the best design. Finally, we decided to sketch it with Creo, then correct and improve it gradually. Before designing directly on Creo, we sketched our design on the following paper, such as: top, front and side-view of the overall project, as well as the detailed parts like hinges, like the following picture.

     

   

     Finally, based on the design we determined, as well as the dimensions that we researched and fitted to all our expected categories, we started applying Creo to sketch our project.

     We started with the most basic parts. First, we started drawing the ring, and then we drew the semi-circle of the tri-leaflet that will appear later.

 

Week 3

While still researching our group accomplished certain things this week.

1. We started a rough draft drawing of what we want our valve to look like.
2. We taught each other the research we individually found.
3. We also are trying to see if it is possible for us to edit our design to make it able to be inserted through a  non-invasive surgery.

The rough draft

-The design for our valve is a mechanical design. We also decided to use a 3 leaflet valve design because of it's advantages mentioned in the Week 2 - Research.

Source: http://roscardioinvest.ru/eng/index.php?id_subpart=5

-The group met outside of lab to discuss the next steps for the design process of the valve. A new sketch was drawn up to help visualize the valve before drawing it in Creo. Here is the two new pictures of the design.

-The first picture shows a more in depth idea of what we plan to draw up in Creo Parametric, while the second picture shows different designs for the possibility of inserting the valve without opening up the patients chest.

Update Week: #2

Anatomy of the Heart:

The center of the circulatory system is the heart, which is the main pumping mechanism. The heart is made of muscle and is divided into halves by a muscular wall called septum. Each halve is also divided into two: a top and bottom part which are separated by another muscular wall. Therefore, there are actually four chambers (spaces) inside the heart. Each top chamber is called an atrium and each bottom chamber is called ventricle.

Source 1

Blood can flow from the atria down into the ventricles because there are openings in the walls that separate them. These openings are called valves because they open in one direction, but won't  open in the opposite direction. Valves are also found between the ventricles and the large arteries that carry blood away from the heart. There are four valves in total:

Source 1

Pumping Mechanism of the Heart:

The heart has two muscle states: diastole and systole. Diastole is the state of relaxation and systole is the state of contraction. Below is a video that carefull explains how the pumping mechanism of the heart works:

Source 2

Bibliography:

1) "Pumping Mechanism of the Heart." WizzNotes. Web. 13 Apr. 2015. 

          <http://wizznotes.com/biology/transport/pumping-mechanism-of-the-heart>.

2) "The Heart and Circulation of Blood." The Heart and Circulation of Blood. Web. 14 Apr. 

           2015. <http://lsa.colorado.edu/essence/texts/heart.html>.

Week 2 - Research

Group Research Topics

Two Leaflet vs. Three Leaflet Designs 

Megan Chatham

Source 1

These are just a few of the many designs for artificial mechanical heart valves available on the market for patients with valvular disease. They are all durable and capable of lasting throughout a patient's lifetime, however they require the use of anticoagulants and often produce a loud clicking sound.

Our group has decided to use either a two or three leaflet valve design for this project. Information was gathered both for and against two and three leaflet valves:

Tri-Leaflet design
Source 2

Bi-Leaflet Valve
Source 3

                                                

                             

                             

                

	Advantages	Disadvantages
Two Leaflet Valve	Highly reliable, Last the patient’s lifetime, Studied extensively, Opens to 90˚ angle, Reduces occurrences of hemolysis	Noisy, Require anticoagulants, Hemorrhaging due to anticoagulants, Scar tissue growth, Trapped leaflets,
Three Leaflet Valve	Highly reliable, Fuse tissue and mechanical design, Natural blood flow due to decreased disturbance of blood, Reduces occurrences of hemolysis, Reduces necessity of anticoagulants due to improved flow characteristics, Reduces noise	New on the market, Still being studied, Opens to 75˚ angle, Scar tissue growth,

1) http://www.medicinenet.com/heart_valve_disease_treatment/page2.htm

2) http://roscardioinvest.ru/eng/index.php?id_subpart=5

3) http://www.onxlti.com/patient-guide/problems-prosthetic-heart-valves/

_________________________________________________________________________________

Blood Flow Through the Heart Valve 

Mark Kundrotas

https://www.youtube.com/watch?v=H04d3rJCLCE

This video gives a lot of insight on how blood flows through the heart valves. The heart valves have 2 different important jobs to circulate blood throughout your body. These jobs are for the valves to open correctly so that blood can empty from the chamber and to close properly so that blood cannot flow the wrong way. If the heart valves are having issues completing these jobs an artificial heart valve replacement is needed.

Source 2

Someone with a mechanical heart valve has to take blood thinners to prevent coagulation. Coagulation in artificial heart valves is when your blood clots at or around the artificial heart valve. It is important to prevent blood clots because they can lead to strokes, heart attacks, or other health problems. There are two different types of blood thinners, anticoagulants and antiplatelet. The anticoagulants affect chemical reactions making it slower for blood clots to form. Antiplatelets prevent platelets from grouping together forming blood clots.  

Source 4

1) https://www.youtube.com/watch?v=Bgy24BMG79o

2) http://www.heart.org/HEARTORG/Conditions/More/HeartValveProblemsandDisease/Heart-Valves-and-Circulation_UCM_450291_Article.jsp

3) http://www.onxlti.com/patient-guide/pros-cons-option-heart-valve-replacement/

4) http://www.heart.org/HEARTORG/Conditions/More/HeartValveProblemsandDisease/Heart-Valves-and-Circulation_UCM_450291_Article.jsp


                                                                                                                                                                   

What Artificial Heart Valves are Made of

Tram Hoang

First, we should know that to create an artificial heart valve, it requires many different materials. Most artificial valves are made of titanium, graphite, pyrolytic carbon, and polyester. The titanium is used for the housing or outer ring, graphite coated with pyrolytic carbon is used for the bi-leaflets, and 100% pyrolytic carbon is used for the inner ring. The pyrolytic carbon is sometimes impregnated with tungsten so that the valve can easily be seen following implantation). The sewing cuff, used to attach the valve to the heart, is made out of double velour polyester

Titanium is used for its strength and biocompatibility. The outer rings come already fabricated from an outside manufacturer and are made from machined bar stock. Lock rings and wire, used to hold the cuff in place, are also made from titanium. The polyester comes in the form of tubes. All plastic components are deburred by the supplier, which involves removing any bumps from the surface. Occasionally the valve manufacturer may have to debur some parts.

Some reports suggest that the mechanical valve available today are able to last indefinitely (over 50,000 years!!!)

Here is good news. Researchers are looking at making heart valves out of plastic material that are flexible enough to simulate the opening and closing action. This approach may not require anticoagulation drugs. Others are working on developing artificial heart valves made from a patient's own cells.

Sources:

http://www.madehow.com/Volume-6/Artificial-Heart-Valve.html

Update #1:

Research for the Artificial Heart Valve has oficially begun! The link below helped us learn the basic principles of how a heart valve works and how our group can create one

http://www.slideshare.net/tammirajuiragavarapu5/prosthetic-valves-the-past-present-and-future-i-tammi-raju

Week 1: Introduction to Artificial Heart Valve Design

Welcome to our Blog!

Our Freshman Design Project topic is to create an Artifical Heart Valve. This is a very complex project but we are sure to do all the research to be successful in our task. To begin our group is comprised of 4 people:

1.) Mario Borjas
2.) Mark Kundrotas
3.) Megan Chatham
4.) Tram Hoang

When choosing a topic the design of an artificial heart valve really stuck out to us. By the end of the 1st class the group was excited to tackle this difficult project topic we had chosen. Our goal is designing a new heart valve that would result to be efficient and improve problems older designs have. The main problem we face as first year engineering students is that we do not currently have all the information that is required. People working on these artificial heart valves have accumulated several years of knowledge and research. This means a lot of research has to be done in order to design our own artificial heart valve. But we would sure make it to be successful!

Source 1

Source 2

1) http://my.clevelandclinic.org/services/heart/disorders/valve/bicuspid_aortic_valve_disease
2) http://www.heart.org/HEARTORG/Conditions/More/HeartValveProblemsandDisease/Types-of-Replacement-Heart-Valves_UCM_451175_Article.jsp