Blood Vessel Activity Lesson Plan - EDGE

TEAK – Bioengineering Clogged Blood Vessel Lesson Plan Page 1

TEAK Traveling Engineering Activity Kits

Biomedical Engineering Kit: The Circulatory and Respiratory Systems Clogged Blood Vessel Activity


Instructor Preparation Guide: 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,

the heart, blood, and blood vessels 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


Figure 1.1 – Clogged Blood Vessel

Blood vessels are the part of the circulatory system that transports blood

throughout the body. Blood vessels become clogged when a material known as plaque

builds up on the interior walls of the blood vessels. Composed of fats, cholesterol,

calcium, and other blood cell waste, the build up of plaque causes the heart to work

harder due to the increase in resistance to flow through the blood vessel. Typical results

of clogged blood vessels are heart attack, stroke, and arrhythmia (irregular heart beat). In

order to reduce the risk of heart attack and stroke due to clogged blood vessels,

biomedical engineers and doctors have designed devices such as stents, balloon catheters,

and catheters to open clogged blood vessels and allow for normal flow conditions to

resume.

Figure 1.2 Balloon Catheter Applications


Blood Vessel Flow Characterization Overview

The flow of fluid particles can be described as either turbulent or laminar.

Laminar flow is flow in which the fluid particles move in smooth layers, or laminas.

Turbulent flow is flow in which the particles rapidly mix as they move along due to

random three dimensional velocity fluctuations. Flow within a blood vessel is

characterized as turbulent flow. Though turbulent flow is not ideal for most practical

applications, it is desirable for blood flow because the random mixing allows for all of

the blood cells to contact the walls of the blood vessels to exchange oxygen and other

nutrients. Flow can be characterized as either laminar or turbulent through the evaluation

of the Reynolds Number for the given flow conditions. Reynolds Number is calculated

by the equation:

µ

ρVD=Re

Where:

ρ = fluid density

V = fluid velocity

D = Tube Diameter

µ = kinematic viscosity

For most applications, if the Reynolds Number is greater than 2300, flow is

characterized as turbulent. If the Reynolds Number is less than 2300, flow is

characterized as laminar. For example, blood flow in the aorta has a Reynolds Number

of around 3400. This is an example of turbulent flow.

Figure 2.0 – Turbulent vs. Laminar Flow


Resources

• Introduction to Fluid Mechanics. 6

th Edition. Fox, McDonald, Pritchard.

• www.wikipedia.com

Image Resources

• Figure 1.0: http://gonatural.com.ph/herbalblog/wp-

content/uploads/2007/07/Circulatory%20system.jpg

Date: January 29, 2009

Time: 9:48 pm

• Figure 1.1: http://images.google.com/imgres?imgurl=http://www.biotech-

weblog.com/50226711/images/atherosclerosis.jpg&imgrefurl=http://www.agorav

ox.com/article.php3%3Fid_article%3D4888&usg=__fHScGPEoARdANkr2qIXN

PyLb5Wk=&h=200&w=250&sz=10&hl=en&start=1&tbnid=dStyit3sgN5bkM:&

tbnh=89&tbnw=111&prev=/images%3Fq%3Dclogged%2Bblood%2Bvessel%26

gbv%3D2%26hl%3Den%26sa%3DG


Time: 9:48 pm

• Figure 1.2: http://www.heart-stint.com/images/angio1a.gif


Time: 2:38 pm

• Figure 2.0:

http://www.cheng.cam.ac.uk/research/groups/electrochem/JAVA/electrochemistr

y/ELEC/l2fig/laminar.gif


Time: 9:48 pm


Activity Preparation Guide – Clogged Blood Vessel Activity

Overview

This kit contains activities for students to gain a better understanding of how the

heart functions and operates for a typical individual and how engineers study heart

behavior in order to design and fabricate medical instrumentation and prosthetics to

improve the quality of human life. It further explains how the heart pumps and circulates

blood to and from the body as the centerpiece of the circulatory system. The main focus

of this kit is the circulatory system, conditions that lead to heart attacks and strokes, and

biomedical engineering solutions.

Learning Objectives

By the end of this lesson, students should be able to…

• Explain what laminar and turbulent flow is.

• Explain what it means for a blood vessel to become blocked.

• Identify bioengineering tools and instruments that can open 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 such as heart rates and blood pressure

in order to identify and eliminate possible design parameters when developing such

biomedical prosthetics and instruments as catheters, balloon catheters, and stents. Just as

an engineer must acquire data from a biological system in order to model, design, and

fabricate a new design, the students participating in this activity will analyze and asses

the flow characteristics of blood flow through blocked and unblocked blood vessels, and

then design and develop devices and approaches to unclog a blood vessel.


Activity Descriptions

A.) Introductory Discussion: Bioengineering and the Heart: 15 Minutes

This discussion will be an introductory discussion 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 strokes and heart

attacks. Additional to this, students will be introduced to the concepts of

laminar and turbulent flow and how such flow conditions may impact the

vessels that they are encompassed in. After this part of the discussion,

students will be introduced to biomedical solutions to prevent heart attacks

and improve blood flow such as catheters, balloon catheters, and stents.

B.) Circulatory System Blood Flow Activity: 15 Minutes

This activity will allow students to observe the flow of blood through a

miniature circulatory system for both blocked and unblocked flow conditions.

During this activity, students will pump “blood” through the miniature setup

for unblocked conditions and observe how easy the heart is able to pump

blood through the blood vessels when the vessels are not blocked. After doing

this, the students will repeat the exercise for the blocked flow conditions and

observe how the heart must work much harder in order to pump blood

throughout the circulatory system now that the blood vessels are blocked.

After completing both of these exercises, the students will begin to

hypothesize various ways in which they will be able to unblock the blocked

blood vessels and increase the flow rate through the circulatory system.

C.) Blood Vessel Flow Analysis and Testing: 15 Minutes

This activity will allow the students to test their hypothesized solution to the

blocked blood vessel as developed from part B of this activity. The students

will be given an unblocked blood vessel and a blocked blood vessel. The

students participating in this activity will first analyze the blood flow through

the unblocked blood vessel and determine the flow rate through this blood

vessel. The students will then do the same for the blocked blood vessel and

determine if the flow rate is greater or less than that of the unblocked blood

vessel. In order for the students to calculate the flow rate through the blocked

and unblocked blood vessel, they will need to apply this simple equation:

TimeeFluidVolumFlowRate ÷=


From this equation for flow rate, the students will be able to calculate and

compare the values for both the blocked and unblocked blood vessels.

After completing their calculations, the student will then design and

determine the best engineering solution to increase the flow rate of the

blocked blood vessel. To complete this “design challenge” activity, the

student will be given materials to construct a stent, catheters, etc. Due to

the number of students participating in each group, the members of each

group will be given engineering titles as part of an engineering team.

Such engineering titles will be that of mechanical engineer, fluids analyst,

engineering data analyst, and a test engineer.

D.) Closing Discussion: Biomedical Applications: 5 Minutes

This closing discussion will tie together the concepts presented throughout the

activity by giving examples of how engineers are currently working on such

technological advances in the field of biomedical engineering as stents,

artificial heart valves, and artificial hearts. During this discussion, students

will be presented with numerous visuals to aid in their ability to understand

the topics and devices being presented to them.

E.) 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.


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.


• 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.


Resources

A.) Wikipedia: www.wikipedia.com

B.) Introduction to Fluid Mechanics. Fox, McDonald, and Pritchard. 6th

Edition.

C.) National Heart and Lung Institute:

http://www.nhlbi.nih.gov/health/dci/Diseases/HeartAttack/HeartAttack_WhatIs.h

tml

D.) http://www.emsc.nysed.gov/ciai/mst/techmap/map.html

E.) http://www.albanyinstitute.org/Education/standards.pdf

F.) http://www.nylearns.org/standards/browsestandards.asp


The Circulatory System

DURATION

45-50 Minutes

CONCEPTS

Bioengineering

Circulatory System

Blood Flow Characteristics

Biomedical Applications


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


Circulatory System Discussion: (5.0 Minutes)


Your heart is the centerpiece of the circulatory system that pumps blood

throughout your entire body. In order to move blood throughout the body, the heart must

act as a pump. As with all other pumps, it can become clogged, break down, and need

repair. This is why it is critical that engineers know how the heart works and functions in

conjunction with the rest of the body in order to design solutions to help keep the heart

working properly.

Simplified Definitions:

A.) Atheroma (ath·er·o·ma) Plaque – A build up of fat and cholesterol from cell

debris on the interior walls of blood vessels.

B.) Arrhythmia – An abnormal heart beat.

C.) Heart Attack - A heart attack occurs when blood flow to a section of heart

muscle becomes blocked.

D.) Stroke – A stoke is a loss in brain function due to the rapid disturbance in the

supply of blood to the brain.

Group Discussion: Clogged Arteries and Biomedical Solutions


What does it mean when a blood vessel is clogged?

• Atheroma Plaque builds up on the interior walls of the artery.

• Prevention of normal blood flow due to a buildup of waste.

What is atheroma plaque made of?

• Calcium

• Fat

• Cholesterol

• Blood Cell Waste


Once a blood vessel becomes blocked, is it easier or harder for the blood to flow?

• It becomes harder for the blood to flow once the blood vessel becomes blocked.

What do you think is an effect of a blocked blood vessel?

• Impedes blood flow or stops it all together.

• Result in a heart attack.

• Results in stroke or heart arrhythmia.


Blood Flow Activity – 15 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 very

hard to pump blood throughout the body.

2. Describe that, if the circulatory system is clogged, the heart has to work harder,

generating a greater force to pump the blood throughout the body. A clogged system

may lead to stroke, heart attacks, or abnormal heart beats.

Materials

1. 1 clogged system per group.

2. 1 unclogged system per group.

3. 1 activity worksheet per student.

Procedure

1. Get the students into 5 groups.

2. Have the students pump water through the miniature circulatory system for the unclogged

configuration.

3. Once each student has had an opportunity to pump water through the system, have the

students record their observations on the given worksheet.

4. Next, have the students pump water through the miniature circulatory system for the

clogged configuration.

5. Once each student has had an opportunity to pump water through the system, have the

students record their observations on the given worksheet.

6. Now that the students have evaluated both the clogged and unclogged circulatory

systems, discuss with the class their findings and observations in terms of the force

required to pump the fluid for the clogged and unclogged setup and how the pumping

force the had to apply compares to the force required by the heart to pump blood.

Expected Results

1. The force required to pump the fluid through the unclogged system should be less than

the force required to pump the fluid through the clogged system.

2. The amount of force required to pump the fluid through these configurations is

representative of the force output required by the heart to pump blood through the

circulatory system.

End Blood Flow Activity


Miniature Circulatory System Worksheet

The Unclogged Circulatory System:

How hard was it to pump the fluid through the system?

Did the fluid flow freely through the “blood vessels”?

Are there any other observations?

The Clogged Circulatory System:

How hard was it to pump the fluid through the clogged system?

Did the fluid flow freely through the “blood vessels”?

Are there any other observations?

The Engineering Evaluation:

Was it harder to pump the fluid through the clogged or unclogged circulatory system?

What do you think will be a result of the clogged circulatory system?


Flow Characterization Discussion: (5.0 Minutes)


The flow of fluid particles can be described as either turbulent or laminar flow.

Laminar flow is flow in which the fluid particles move in smooth layers, or laminas.

Turbulent flow is flow in which the particles rapidly mix as they move along due to

random three dimensional velocity fluctuations. Flow within a blood vessel is

characterized as turbulent flow. Though turbulent flow is not ideal for most practical

applications, it is desirable for blood flow because the random mixing allows all the

blood cells to contact the walls of the blood vessels to exchange oxygen and other

nutrients.

Simplified Definitions:

A.) Laminar Flow – The smooth flow of fluid particles along a straight line.

B.) Turbulent Flow – The rapid and chaotic flow of fluid particles along a straight

line.

Group Discussion: Laminar and Turbulent Flow


How would you describe the flow of water out of a drinking fountain?

• Smooth

• Gentle

• Slow

How would you describe the flow of water out of a fire hose?

• Very Fast

• Chaotic

• Rough

• Hard

- Explain to the students that the drinking fountain is an example of

laminar flow. Laminar flow is when the flow of a fluid is very smooth.

- Explain to the students that the fire hose is an example of turbulent flow.

Turbulent flow is when the flow of a fluid is very chaotic, fast, and wants

to go in many directions.


What do you think the flow of blood through a blood vessel is? Is it Laminar or

Turbulent?

• Flow within a blood vessel is characterized as turbulent flow.

• Explain to the students that blood travels at about 23 mph through their

blood vessels and that the heart pumps 5L of blood every minute

throughout the body.

Do you think this is good or bad for your blood vessels? And why?

• This good for your blood vessels.

• It is desirable for blood flow because the random mixing allows all the blood

cells to contact the walls of the blood vessels to exchange oxygen and other

nutrients.

Why do you think an Engineer might need to know about how blood flows within a

blood vessel?

• To determine if the flow is laminar or turbulent.

• To model blood flow accurately.

• To design and develop medical instruments to improve blocked flow.

Explain to the students these three biomedical applications utilized to increase the flow

of blood through clogged and blocked blood vessels:

A.) Catheter – A tube inserted into a blood vessel so as to increase the flow of

blood.

B.) Balloon Catheter – A type of soft catheter with an inflatable balloon at its tip that

is used to enlarge a narrow opening within the body.

C.) Stent – A tube inserted into the body to prevent or counteract a localized flow

constriction.


Blood Vessel Flow Analysis Activity

Learning Objectives

By the end of this exercise, students should be able to …

1. Describe what laminar and turbulent flow is.

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 Water collection bin.

2. 1 Plastic measuring cup.

3. 1 Tripod stand.

4. 1 Clogged blood vessel.

5. 1 Unclogged blood vessel.

6. 1 Stopwatch.

7. 1 Activity worksheet per engineering team.

8. 1 Can of playdoh.

9. 1 Package of catheter supplies.

Procedure

1. Have the students get into 5 groups, with each student assuming one of the

engineering roles.

2. Set up the unclogged blood vessel on top of the tripod stand. Next, place the

water collection bin in front of the unclogged blood vessel.

3. Take the measuring cup, and fill it with 2 cups of water. Next, in a steady

manner, have a student poor the water through the blood vessel and into the water

collection bin. While one student pours the water, another student should be

timing the amount of time it takes for the water to flow through the vessel and

into the bin. This value should be recorded on the activity worksheet. During this

step, another student should take the can of playdoh and clog the other blood

vessel in preparation for the next exercise.


4. Set up the clogged blood vessel on top of the tripod stand. Next, place the water

collection bin in front of the clogged blood vessel.

5. Take the measuring cup, and fill it with 2 cups of water. Next, in a slow and

steady manner have a student poor the water through the clogged blood vessel and

into the water collection bin. While one student pours the water, another student

should be timing the amount of time it takes for the water to flow through the

vessel and into the bin. This value should be recorded on the activity worksheet.

6. After conducting the blood vessel flow analysis for both the clogged and

unclogged blood vessel, the students should calculate the flow rate for the clogged

and unclogged blood vessel from the equation given on the activity worksheet.

7. Next, the students should take the materials out of the package of catheter

supplies. From the materials given, the students should construct a balloon

catheter. Once constructed, have the students insert the catheter into the clogged

blood vessel. Once setup, have the students repeat step 5 of this procedure and

record the amount of time it takes for the water to flow through the vessel now

that the catheter has been inserted.

8. After conducting the blood vessel flow analysis for the application of the balloon

catheter, have the students recalculate the flow rate from the given equation on the

activity worksheet.

9. The students have now completed all the exercises and should finish filling out

the activity worksheet. Once completed, discuss with the class the findings of

their experiments.

Expected Results: These results are based on average values taken from three trails of

testing.

Unclogged Blood Vessel Results

Volume Time Flow Rate

500 mL 12.27 s 40.75 mL/s

Clogged Blood Vessel Results


500 mL 16.43 s 30.43 mL/s

Clogged Blood Vessel with Balloon Catheter


500 mL 14.26 s 35.06 mL/s

End Blood Vessel Flow Analysis Activity


Blood Vessel Flow Analysis Worksheet

Governing Equation: Flow Rate = Volume ÷ Time

Analysis:

Unclogged Blood Vessel Analysis:


Clogged Blood Vessel Analysis:


Clogged Blood Vessel with Balloon Catheter:


Post Analysis Questions:

Is the flow rate greater for the clogged or unclogged blood vessel?

Which blood vessel do you think is turbulent flow and which do you think is laminar?

What part of your design to unclog the blood vessel did you like? What part of the

design would you change or improve if you were to do this experiment again?


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.

Which is an example of turbulent flow? The clogged or unclogged blood vessel?

• The clogged blood vessel is a better representation of turbulent flow conditions.

However, in reality, flow through an actual blood vessel is always turbulent.

Was the balloon catheter a good method for increasing the flow rate through the blood

vessel?

• In actual practice, yes, catheters will significantly increase blood flow and

decrease the risk for stroke and heart attack. For this exercise, the difference in

values will be minimal.

• Balloon catheters are a good application when unclogging blood vessels around

the heart, or within larger branches of the body such as the arms and legs.

What do you think are some other possible solutions to blocked flow in blood vessels?

• Stents

• Medication

Documents

Blood Vessel Activity Lesson Plan - EDGE