TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
Page 1
TEAK
Traveling Engineering Activity Kits
NEW PIC HERE
Biomedical Engineering Kit:
The Circulatory and Respiratory Systems
Clogged Blood Vessel Activity
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
Instructor Preparation Guide:
Page 2
Blood Vessel Activity
Bioengineering Overview
Bioengineering is the application of engineering principles to address challenges
in the fields of biology and medicine. Bioengineering is the application of the principles
of engineering design to the full spectrum of living systems.
Circulatory System Overview
The main components of the human circulatory system are the heart, blood, and
the blood vessels that carry blood through the rest of the body. These three components
form what is known as the cardiovascular system. The circulatory system includes two
loops throughout the body know as the pulmonary circulation loop and the systemic
circulation loop. The pulmonary circulation loop is the loop in which the blood becomes
oxygenated while the systemic circulation loop is the loop that provides the oxygen rich
blood to the rest of the body.
Figure 1.0 - The Human Circulatory System
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Clogged Blood Vessel Lesson Plan
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Figure 1.1 – Thrombus in a Blood Vessel
Blood vessels are the part of the circulatory system that transports blood throughout the
body. When blood vessels become damaged, blood clots natural form out of blood cells
and fibrin and prevent vessels from bleeding. Occasionally, blood clots form on their
own for no reason, and they usually dissolve without causing harm, but sometimes these
clots become lodged in a vessel and disrupt blood flow. A clot that forms in the lumen
(the open space) of a blood vessel is called a thrombus, and a clot that forms and then
travels to another place is called an embolus. The main dangers of a thrombus or
embolus is that it will block blood flow completely, resulting in oxygen starvation to
organs. There are several ways of treating a blood clot, anticoagulants help prevent clot
formation and clot busters help dissolve clots, but when a patient is in immediate danger
the physician may decide surgery is prudent. In this case, the physician will either
implant a stent or use a balloon catheter to remove the clot. Balloon catheters remove
clots by being inserted past the clot, inflating the balloon, and pulling the clot through the
vessel and out of the incision; this procedure is called a thrombectomy.
Figure 1.2 Various Balloon Catheters
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
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Pressure and Flow Rate Overview
Pressure is the quantitative measure of force over a given area. Within blood vessels,
blood pressure is a very important factor doctors consider. High blood pressure could
lead to damaging the interior walls of blood vessels, and is also generally unhealthy to the
organs in the body. Low blood pressure risks organs becoming oxygen starved (such as
the brain) and degenerating. Blood clots can have an effect on blood pressure if the
thrombus is located in key locations throughout the body. The heart has to pump harder
to maintain blood flow rate, which is also a risk to vessel walls and can increase the
likelihood of clots forming. In this way, flow rate is also very important to healthy blood
vessels. Flow rate is the measure of how quickly a given volume of liquid is traveling.
The general equations to calculate flow rate and pressure are given below:
𝑃𝑟𝑒𝑠𝑠𝑢𝑟𝑒 =
𝐹𝑜𝑟𝑐𝑒
𝑆𝑢𝑟𝑓𝑎𝑐𝑒 𝐴𝑟𝑒𝑎
𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒 =
𝐿𝑖𝑞𝑢𝑖𝑑 𝑉𝑜𝑙𝑢𝑚𝑒
𝑇𝑖𝑚𝑒
Figure 2.0 Physical Representation of Pressure
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
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Resources
Introduction to Fluid Mechanics. 6th Edition. Fox, McDonald, Pritchard.
www.wikipedia.com
“Blood Clots”. Heart Health. iVillage Inc 2007. Visited Feb 2010.
<http://yourtotalhealth.ivillage.com/blood-clots.html>
Image Resources

Figure 1.0: http://gonatural.com.ph/herbalblog/wpcontent/uploads/2007/07/Circulatory%20system.jpg
Date: January 29, 2009
Time: 9:48 pm

Figure 1.1:
Durning, Marijke. “Pregnant Women – Managing and Preventing Blood Clots.”
Women’s Health. b5media June 2008. Visited Feb 2010.
<http://www.blisstree.com/articles/pregnant-women-preventing-andmanaging-blood-clots-631/>.

Figure 1.2:
“Know-how Thomas Fogarty”. Inventing Modern America: from the Microwave
to the Mouse. The Lemelson MIT Program, 2001. Visited Feb 2010.
<http://www.liu.edu/CWIS/CWP/library/workshop/citmla.htm>.

Figure 2.0:
Benson, Tom. Air Pressure. Visited Feb 2010.
<http://wright.nasa.gov/airplane/pressure.html>.
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
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Activity Preparation Guide – Clogged Blood Vessel Activity
Overview
This kit contains activities for students to gain a better understanding of how
engineers and doctors must work together to form medical solutions to health problems.
It explains the basics and purposes behind clot formation within the body and the tools
doctors have to combat blockage within blood vessels. This kit specifically focuses on
the basic design and function of a balloon catheter, and how doctors can use it to perform
a thrombectomy (surgical removal of a thrombus). Along with these concepts, the
activities are designed to introduce flow rate and pressure and show how they affect the
human body.
Learning Objectives
By the end of this lesson, students should be able to:

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Explain what flow rate is.
Explain what pressure is.
Explain what it means for a clot to form in a blood vessel.
Identify bioengineering tools and instruments that can remove a clot from a
blocked blood vessel and increase blood flow.
Explain how engineering contributes to problem solving in the body.
Engineering Connection
Engineers work with doctors and surgeons to create biomedical instrumentation to
measure and record human biological functions. These functions include heart rate and
blood pressure. This is a necessary step in order to identify and eliminate possible design
parameters when developing biomedical prosthetics and instruments such as catheters,
balloon catheters, and stents. Just as an engineer must acquire data from a biological
system in order to model and fabricate a new design, the students participating in this
lesson will analyze and asses the flow rate of blood through a clotted blood vessels,
design and develop a balloon catheter to remove the clot, and then measure the new flow
rate through the cleared blood vessel.
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Clogged Blood Vessel Lesson Plan
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Activity Descriptions
A.) Introductory Discussion: Bioengineering and the Heart: 10 Minutes
This discussion will be an introduction to the topic of bioengineering and the
broad scope that this discipline of engineering encompasses. This discussion
will further examine the function of blood vessels and the conditions that arise
within them that lead to clotting. Additional to this, students will be
introduced to the concepts of pressure and flow rate and how such engineering
concepts may have an impact on blood vessels. After this part of the
discussion, students will perform an activity that shows how pressure and flow
rate can be related, and the effect a blood clot can have within a blood vessel.
B.) Circulatory System Blood Flow Activity: 10 Minutes
In this activity, students will calculate the pressure applied to a balloon full of
water. They’ll do this by measuring the area of a surface that is pressing
down on a balloon, and knowing the weight on the surface, calculate the
pressure being exerted. The students will force water through an imitation
blood vessel with a mostly closed ball valve, and given the volume of water,
will calculate the flow rate. This activity is mainly a set up for a following
activity where they will return to the imitation blood vessel, but they will then
open the ball valve more and record an increased flow rate.
C.) Thrombectomy discussion and testing: 20 Minutes
In this section, the students will learn about what a thrombectomy is and how
doctors use a balloon catheter to surgically remove a thrombus. The
discussion is designed to get the students thinking about the challenges
engineers face in designing a balloon catheter, and the considerations doctors
have to make when using them in surgery. After the discussion, students will
get an opportunity to apply what they have learned in designing their own
balloon catheter to remove “clots” (eraser bits) from a “blood vessel” (PVC
piping). They will be given a choice between different lengths and diameters
of tubing as well as different size balloons, and before they build the actual
balloon catheter they must consciously decide as a group which pieces to use
and why. This is meant to give an important sense of the design process real
engineers go through. After they test it, if there is time, they will be allowed
to change their design and test again. After this test, they will return to the
previous activity, demonstrating that the clotted blood vessel has been cleared
and now has an increased flow rate.
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Clogged Blood Vessel Lesson Plan
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D.) Blood Flow Activity Part Two: 10 Minutes
After the students have performed the thrombectomy on the blood vessel, they
will return to the imitation blood vessel activity and redo the experiment. This
time, when they go through the activity, they will open the ball valve
completely. This represents how blood flow is improved when a clot is
removed from a blood vessel. If time allows, the students will get an
opportunity to try the experiment out on different levels of “clotting” to see
how blood flow is affected. They will calculate the blood flow for the
different degrees of blockage and see how they compare. The experiment will
show students that blood travelling through a clear blood vessel flows much
faster than blood through a blocked vessel. There will also be a connection to
pressure, where the students would theorize how adding more weight would
affect the flow rate through the tubing.
E.) Closing Discussion: Biomedical Applications: 10 Minutes
This closing discussion will tie together the concepts presented throughout the
activities. The instructor will ask questions designed to get students thinking
critically about their results and what they observed. As a class, the students
will answer many of the questions they answered as a group, discussing the
pros and cons of their designs and what challenges they faced. The purpose of
this is that different groups may decide upon fundamentally different designs
and get varying degrees of success. By discussing the results as a group,
students will see how different perspectives can lead to different outcomes,
and will be exposed to observations they may not have made on their own.
F.) Engineering Team Roles:
Mechanical Engineer – Develops a solution to increase the flow velocity
based the materials given along with the assistance of the other team
members.
Fluids Engineer – Calculates and determines the Reynolds Number for
the unblocked and blocked blood vessel.
Engineering Data Analyst - Collects data throughout the experiment.
Test Engineer - Supervises and assists in the setup of the blood vessel test
configuration.
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
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New York State Learning Standards
MST
1
E
Engineering
Design
Discuss how best to test the solution; perform the test under teacher supervision;
record and portray results through numerical and graphic means; discuss orally
why things worked or did not work; and summarize results in writing, suggesting
ways to
make the solution better
MST
1
E
Engineering
Design
Plan and build, under supervision, a model of the solution using familiar materials,
processes, and hand tools
New York State Health Learning Standards
a.) Standard 3: Resource Management
1. Students: Distinguish between invalid and valid health information,
products, and services.
2. Students: Analyze how the media and technology influence the selection
of health information, products, and services.
New York State Technology Learning Standards
a.) Standard 1: Engineering Design
3. Engineering design is a repetitive process involving modeling,
optimization, and finding the best solution within the given constraints
that is used to develop technological and innovative solutions to technical
problems.
4. Students:
• Activate devices.
• Recognize why an object or choice is not working properly.
• Recognize how a defective simple object or device might be fixed.
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Clogged Blood Vessel Lesson Plan
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• Under supervision, manipulate components of a simple,
malfunctioning device to improve its performance.
• Design a structure or environment.
b.) Standard 5: Management of Technology
- Students: Must work cooperatively with others on a joint task.
New York State Math Learning Standards
a.) 6th Grade Standards
5. Students will apply and adopt a variety of appropriate strategies to solve
problems.
6. Students will organize and consolidate their mathematical thinking
through communication.
7. Students will determine what can be measure and how, using appropriate
methods and formulas.
8. Students will collect, organize, display, and analyze data.
New York State Science Learning Standards
a.) Intermediate Standard 1: Analysis, Inquiry, and Design.
9. T1.1a: Identify a scientific or human need that is subject to a
technological solution which applies scientific principles.
10. T1.3a: Identify alternative solutions base on the constraints of the design.
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
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Resources
“Blood Clots”. Heart Health. iVillage Inc 2007. Visited Feb 2010.
<http://yourtotalhealth.ivillage.com/blood-clots.html>
“Know-how Thomas Fogarty”. Inventing Modern America: from the Microwave to
the Mouse. The Lemelson MIT Program, 2001. Visited Feb 2010.
<http://www.liu.edu/CWIS/CWP/library/workshop/citmla.htm>.
Wikipedia: www.wikipedia.com
Introduction to Fluid Mechanics. Fox, McDonald, and Pritchard. 6th Edition.
National Heart and Lung Institute:
http://www.nhlbi.nih.gov/health/dci/Diseases/HeartAttack/HeartAttack_Wh
atIs.html
http://www.emsc.nysed.gov/ciai/mst/techmap/map.html
http://www.albanyinstitute.org/Education/standards.pdf
http://www.nylearns.org/standards/browsestandards.asp
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
The Circulatory System
DURATION
45-50 Minutes
CONCEPTS
Bioengineering
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TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
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Circulatory System
Blood Flow and Clotting
Biomedical Solutions
Bioengineering Discussion: (5.0 Minutes)
Background Information:
Bioengineering is the application of engineering principles to address challenges
in the fields of biology and medicine. Bioengineering applies the principles of
engineering design to the full spectrum of living systems.
Group Discussion:
Bioengineering Background
(Pose the following questions to the group and let the discussion flow naturally…
try to give positive feedback to each child that contributes to the conversation)
What do you think bio (biology) means?



The study of life and a branch of the natural sciences that studies living organisms
and how they interact with each other and their environment.
The study of the environment.
The study of living organisms and living systems.
What do you think engineering is? What do you think it means to be an engineer?

A technical profession that applies skills in:
o Math
o Science
o Technology
o Materials
o Structures
Discuss with the students what bioengineering is and the broad scope of areas that
bioengineering includes. For this discussion, provide students with examples of
bioengineered products and applications.
 Bioengineering is the application of engineering principles in the fields of
medicine, biology, robotics, and any other living system.
 Examples of products that have been bioengineered are:
o Artificial Hearts
o Artificial Heart Valves
o Stents
o Catheters
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
Circulatory System Discussion:
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(5.0 Minutes)
Background Information:
Your heart is the centerpiece of the circulatory system that pumps blood
throughout your entire body. Blood vessels carry the blood to all the different organs and
back to the heart. In case the vessels are damaged (such as through cuts) the body
naturally forms clots to repair itself. Sometimes, these clots don’t dissolve and end up
restricting blood flow through the vessels. Engineers and doctors need to have an indepth understanding of these clots in order to discover ways of removing them and to
keep blood vessels clear. If a blood vessel does become blocked, it reduces the lumen
and restricts blood flow.
Simplified Definitions:
A.) Blood Clot – A group of blood platelets and fibrin that group together to prevent
blood loss
B.) Lumen – The open cavity of a blood vessel
C.) Thrombus – A blood clot
D.) Flow rate – A measure of how quickly a volume of liquid is moving
E.) Pressure – A measure of a force over a given volume
Group Discussion:
Clogged Arteries and Biomedical Solutions
(Pose the following questions to the group and let the discussion flow naturally…
try to give positive feedback to each child that contributes to the conversation)
Why do blood clots form?


In order to repair damaged blood vessels
If they didn’t, people would never stop bleeding
What do you think a clot could be made of?


Blood Platelets
Fibrin (small strands in the blood stream)
Once a clot forms in a blood vessel, do you think it is easier or harder for the blood to
flow?

It becomes harder for the blood to flow
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Clogged Blood Vessel Lesson Plan
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The clot partially (or entirely) fills the lumen, restricting flow
What do you think is an effect a clot may have on a blood vessel?

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Impedes blood flow or stops it all together
Result in a oxygen starvation of organs
Can results in stroke, heart attack, or pulmonary embolism
The following questions are meant to get the students thinking about the next part in
the lesson.
How do you think doctors prevent and remove clots?


Medication (anticoagulants, blood thinners)
Surgery (thrombectomy)
When designing medical devices, do you think engineers have to work closely with
doctors?



Engineers need to know as much as they can about the problem to design a
solution
Engineers need to know their design parameters (size/material constraints etc.)
Eventually, doctors will be needed to test the design
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Clogged Blood Vessel Lesson Plan
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Blood Flow Activity 1 – 10 Minutes
Learning Objectives
By the end of this exercise, students should be able to:
1. Describe that if the circulatory system is blocked, blood flow is hindered and slows in the
vessels.
2. Understand the link between pressure and blood flow in this scenario, where floor rate is
directly affected by pressure.
Materials
1. 1 Blood vessel kit per group.
2. 1 Activity worksheet per group.
Procedure
1. Get the students into 6 groups.
2. Pass out one kit and one handout per group.
3. Have the students follow the steps on the handout, a simplified version of the handout
will continue in this procedure.
4. There should be water in the water bottle, open the ball valve and tip the water into the
balloon on the opposite end of the blood vessel. To speed the flow, remove the pin from
the bottle; just be sure that the hole stays right-side up.
5. When all the water is in the balloon, close the ball valve. (At this point, the pin should be
out of the water bottle.)
6. Have the students use the ruler to calculate the surface area of the weight.
7. Position the weight so it is applying pressure to the balloon.
8. With one student keeping an eye on the water level in the bottle, and another student
keeping time, a third student will open the ball valve to its lowest setting.
9. After completing the experiment, open the ball valve fully, drain the water back into the
balloon, and close the ball valve.
10. Calculate the flow rate, using the time and given amount of water.
11. Record any observations and answer the questions on the handout.
Expected Results
End Blood Flow Activity 1
TEAK – Bioengineering
Clogged Blood Vessel Lesson Plan
Thrombectomy Discussion:
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(5.0 Minutes)
Background Information:
There are many different ways to prevent and treat a blood clot, but if the doctor
sees an immediate danger to the patient, they may decide to perform a thrombectomy. A
thrombectomy is the surgical removal of a blood clot and is performed with a balloon
catheter. A balloon catheter is a long tube which travels through an incision in the blood
vessels. It penetrates the clot, and then a small balloon at the end of the tube is inflated,
filling the lumen, and the entire clot is pulled out through the incision. One of the
dangers of a thrombectomy is that the balloon catheter will damage the blood vessel,
encouraging the formation of new clots.
Simplified Definitions:
A.) Thrombectomy – The surgical removal of a thrombus
B.) Balloon Catheter – A device doctors use to surgically remove blood clots
Group Discussion:
Thrombectomy
(Pose the following questions to the group and let the discussion flow naturally…
try to give positive feedback to each child that contributes to the conversation)
When designing a balloon catheter, what do you think are some issues engineers
consider?

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
Length of the tubing (catheter)
Size of the balloon
Material the balloon is made of
How much air is necessary to inflate the balloon
What are some dangers in performing a thrombectomy?
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
Possible damage to vessel walls
Dislodging clots that could cause more damage in other parts of the body
The patient could be allergic to the material of the apparatus
What do you think could happen if the clot is not treated?
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

The clot could grow until it blocks the vessel completely
Reduced blood pressure causes the heart to have to work harder, could lead to
an increase in blood pressure (if the clot is in a vital location)
Clots can damage vessel walls
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Clogged Blood Vessel Lesson Plan
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Clots can become dislodged and fully block a vessel in the heart or lungs.
The following questions are meant to get the students thinking about the procedure
involved in a thrombectomy.
Do you think it’s important for doctors to know how a balloon catheter is constructed?


Doctors, not engineers, will be responsible for using the equipment
If a doctor is to perform surgery with the tool, he must know as much about it
as possible
What do you think could happen if a doctor were to accidently force part of a clot down
a blood vessel?



If the thrombectomy were performed incorrectly, and part of the clot became
dislodged, it could travel to the heart or lungs and stop blood flow
If a doctor is to perform surgery with the tool, he must know as much about it
as possible
This will set up part of the activity, where they must understand why it’s
important that pieces don’t escape through the wrong end
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Clogged Blood Vessel Lesson Plan
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Balloon Catheter Activity – ? Minutes
Learning Objectives
By the end of this exercise, students should be able to …
1. Describe the use and purpose of a balloon catheter
2. Identify biomedical solutions and applications to unclog a clogged blood vessel.
3. Explain how engineering contributes to problem solving in the body.
Materials
1. 1 Blood vessel kit per group.
2. 1 Activity worksheet per group.
Procedure
1. Have the students remain in the six groups from the previous activity, with each student
assuming one of the engineering roles.
2. Have the students follow the steps on the handout, a simplified version of the handout
will continue in this procedure.
3. Take out the bag with the parts to the balloon catheter, examine the materials given.
4. Turn the lid upside down onto the box, with the clogged blood vessel facing upright.
5. As a group, discuss the advantages and disadvantages each of the parts will give you,
then decide the best way to construct the balloon catheter.
6. *Note, if a group has trouble, the easiest design is the smallest balloon, attached with the
rubber band to the 3/8” long tubing. This tubing can easily be fitted to the hand pump.
Try to give them hints if they have trouble.
7. Have the students “clot” the blood vessel by putting the eraser pieces into the PVC
piping and shaking the pipe to disperse the pieces.
8. Build the balloon catheter as per the design decided upon.
9. Using the balloon catheter, remove the blood clots as best as possible, making sure not to
let any pieces fall out the wrong end.
10. When the experiment is completed, based on the remaining time, the students will have
the option of redoing the experiment with another design; follow the steps 5-9 to repeat
the procedure.
11. Have the students discuss what they found, and record their observations and answer the
questions on the handout.
Expected Results:
End Balloon Catheter Activity
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Clogged Blood Vessel Lesson Plan
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Blood Flow Activity 2 – ? Minutes
Learning Objectives
By the end of this exercise, students should be able to…
1. Describe that if the circulatory system has no clogs, the heart does not have to work as
hard to pump blood throughout the body.
2. Describe that a clot can directly lead to reduced blood flow, causing the heart to have to
pump harder, and also, the more clots in a person’s body, the less healthy for the heart.
Materials
1. 1 Blood vessel kit per group.
2. 1 Activity worksheet per group.
Procedure
1. Have the students remain in the six groups from the previous activity, with each student
assuming one of the engineering roles.
2. Pass out one handout per group.
3. Have the students follow the steps on the handout, a simplified version of the handout
will continue in this procedure.
4. This is a repeat of the previous blood flow activity. Have the students prepare the kit as
they did before.
5. The amount of “clotting” in this experiment will depend on the results from the balloon
catheter activity.
6. Have them repeat the experiment from the previous blood flow activity.
7. After completing the experiment, in order to clean up, have the students drain the water
back into the water bottle, make sure to re-insert the pin so water doesn’t leak.
Expected Results
End Blood Flow Activity 2
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Clogged Blood Vessel Lesson Plan
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Concluding Discussion
(Pick and choose depending on student questions/responses to the activity worksheet)
Was the flow rate greater for the clogged blood vessel or the unclogged blood vessel?

The flow rate should be greater for the unclogged blood vessel
What factors did the group consider in choosing how to make the balloon catheter?



Length/diameter of tubing
Size of balloon
Can be a variety of answers, try to let the discussion flow naturally
What problems did your group face when performing the thrombectomy?




Hard to see where the clot was
Balloon too big/small
Didn’t get all the clot out
Can be a variety of answers, try to let the discussion flow naturally
How did you overcome these problems?


Changed design
Can be a variety of answers, try to let the discussion flow naturally