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