Hands-on Activity: Clearing a Path to the Heart
Educational Standards :
Pre-Req Knowledge (Return to Contents)
A basic knowledge of the human circulatory system, blood flow and artery clearing, as provided by the associated lesson, Body Circulation
Learning Objectives (Return to Contents)
After this activity, students should be able to:
Materials List (Return to Contents)
Each group needs:
For the entire class to share:
Introduction/Motivation (Return to Contents)
In 2003, a 14 year old boy in China experienced severe chest pain during exercise. At the hospital, doctors found that he had a clogged artery, and if they were not able to clear it, he would go into cardiac arrest and experience heart failure. Luckily, the doctors were able to use an engineered stent to open his artery and prevent heart failure.
Do you know anyone who has had a heart attack? (Ask students to raise their hands.) Do you think that heart attacks are common? Why or why not? What causes them?
In a properly working human circulatory system, blood vessels are clean and smooth (like clean pipes). However, during the course of a lifetime, sometimes material coats the interior walls of blood vessels. This plaque, whether it hardens and stays in place, or hardens and gets dislodged, can have significant health consequences. Having material blocking the normal blood flow restricts the movement of blood, thus preventing sufficient nutrients and oxygen from reaching all parts of the body. Having plaque material moving though the blood vessels may also result in that material eventually encountering a smaller blood vessel and blocking any blood from going through, which prevents nutrients and oxygen from reaching everywhere they are needed. The problems this can cause are significant, problems such as heart attacks and strokes.
The best way to avoid these medical conditions is prevention via things like healthy eating and exercise. However, at the point when blockage is found, it must be treated to avoid health problems. Engineers and doctors have designed various ways to unclog or unblock plaque-coated blood vessels. That's what we're going to look at today—heart attack and stroke treatment and prevention. How exactly is blood flow restored to the heart when plaque, or a blood clot, is blocking blood flow? Every day biomedical, mechanical, chemical and electrical engineers (and others types, too) work with medical doctors to devise more effective treatments for heart attacks and strokes. Today, we are going to see if we can do the same.
What ideas do you have about how we might unclog a blocked artery? (Listen to and encourage student brainstorming and ideas.) Currently, three primary treatments for clogged arteries are in common use (optional; show students Three Methods to Treat Blocked Arteries as either an overhead transparency or printouts, depending on whether or not you want to show them these ideas or wait until activity end). The first two are types of angioplasty, or recreating of the canal in the blood vessel. The first method is a balloon catheter in which a small balloon is passed through the artery to the clogged area where it is inflated, compressing the plaque and opening the artery to greater flow. The second method is similar to the balloon catheter with the addition of a stent surrounding the balloon, so when the balloon inflates, the stent remains behind to keep the plaque pinned against the walls. The third method is a bypass surgery in which the blocked section of the artery is removed and the artery is reconnected, free of the blockage.
Vocabulary/Definitions (Return to Contents)
Procedure (Return to Contents)
Before the Activity
With the Students: Design and Prototype
With the Students: Communication and Testing
With the Students: Conclusion and Reflection
Attachments (Return to Contents)
Troubleshooting Tips (Return to Contents)
Make sure students create feasible solutions, for example, make sure their devices fit into the tubes and have a way of removing or flattening the plaque.
Make sure teams incorporate "lessons learned" from their first design/test as they create revised and improved second designs.
Assessment (Return to Contents)
Brainstorming: Have students brainstorm different possible ways a clogged artery might be cleared without harming the patient. Do this before explaining current practices. Remind students that brainstorming is the time to be very creative. During brainstorming, no idea or suggestion is "wrong" or "ridiculous." Respectfully listen to all ideas and build on them.
Activity Embedded Assessment
Design Process: Visit each group and ask the following questions, depending on the team's stage in the design process:
Worksheet: Have students complete the activity worksheet; review their answers to gauge their understanding of the subject.
Communicating the Results: Have student teams present their designs to the class. Have them share why they chose that design, what worked, what did not work, and ways in which the design might be improved.
Activity Extensions (Return to Contents)
So that the model designs are more lifelike, have students create catheter devices that could be used while water is flowing through the system.
Have teams create engineering presentations that they would give to manufacturing companies, hospitals or medical personnel highlighting the benefits of their particular medical devices.
Activity Scaling (Return to Contents)
Additional Multimedia Support (Return to Contents)
See a good drawing of coronary balloon angioplasty at this National Institutes of Health website: http://www.nhlbi.nih.gov/health/dci/Diseases/Angioplasty/Angioplasty_howdone.html
References (Return to Contents)
Coronary Artery Bypass Surgery. Last updated November 26, 2008. Medline Plus, US National Library of Medicine and National Institutes of Health. Accessed December 8, 2008. http://www.nlm.nih.gov/medlineplus/coronaryarterybypasssurgery.html
Dictionary.com. Lexico Publishing Group, LLC. Accessed December 10, 2008. (Source of some vocabulary definitions, with some adaptation) http://www.dictionary.com
Myocardial Infarction. Last modified December 8, 2008. Wikipedia Free Online Encyclopedia. Accessed December 10, 2008. http://en.wikipedia.org/wiki/Heart_attack
What Is Coronary Angioplasty? Last updated July 2007. Diseases and Conditions Index, National Heart Lung and Blood Institute. Accessed December 10, 2008. http://www.nhlbi.nih.gov/health/dci/Diseases/Angioplasty/Angioplasty_WhatIs.html
Your Heart, Kids' Health Topics. Last updated March 7, 2006. Children, Youth and Women's Health Service. Accessed December 10, 2008. http://www.cyh.sa.gov.au/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=1446
ContributorsTodd Curtis, Jay Shah, Malinda Schaefer Zarske, Denise W. Carlson
Copyright© 2008 by Regents of the University of Colorado.
Supporting Program (Return to Contents)Integrated Teaching and Learning Program, College of Engineering and Applied Science, University of Colorado Boulder
Acknowledgements (Return to Contents)
This digital library content was developed by the Integrated Teaching and Learning Program under National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.