Engineering in Medicine

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Goal: To learn about engineering in medicine through exploring 3D printed prosthetics

Emma O’Shea

Breakout Development Team

Kristine Budill

College: Yale and MIT

Major: Electrical Engineering, BS & MS

Industry Experience: General Electric Aircraft Engines, ITT Fluid Technology, Haemonetics

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Dylan Weber

College: Fairfield University

Major: Mechanical Engineering, BS

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College: Bucknell University

Major: Biomedical Engineering

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Part One: Engineering in Medicine

Engineering in Medicine

• Engineering in medicine is also known as Biomedical engineering
• Biomedical engineering is the application of engineering principles and design concepts to medicine and biology for healthcare purposes

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Part One: Engineering in Medicine

What does a Biomedical Engineer do?

• Biomedical engineers design and analyze:
• Prosthetics and braces
• Surgical devices
• Medical models
• Dental devices
• Medicine and treatments
• Cells and tissue
• And many more!
• One field which has completely revolutionized Biomedical engineering is 3D Printing

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Part One: Engineering in Medicine

Read Me!

3D Printing in Medicine

Part One: Engineering in Medicine

• 3D printing has changed the world of Biomedical Engineering because it is cheap, products are customizable, and the printing process is fast

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• Some applications include dental implants, auditory devices, and bone implants

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Part One: Engineering in Medicine

Answer Me!

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Write down three new things you learned / find interesting!

E-Nable

• Some things to note about the design of most E-Nable prosthetics:
• Different pieces are 3D printed to act as the bones.
• Pins are either bought or 3D printed to serve as joints, allowing the bones to move around.
• Different types of elastic or string wrap around the joints and connect to different parts of the bones, providing tension and serving as muscles, tendons, or ligaments. These are what allow the prosthetics to open and close in a controlled manner.
• In order to attach a prosthetic to a client, there must be some sort of socket where their remaining limb can enter and push on tensioner strings. Additionally, bands may extend past the prosthetic to the client’s remaining joints to provide even more control.

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Part One: Engineering in Medicine

Read Me!

Tension string attached to wrist joint, and socket at base of finger

Open socket for palm, when wrist bent inward tension strings are pulled and fingers close

E-Nable

These sections are different printed pieces, or “bones” of the finger.

Part One: Engineering in Medicine

You may not be able to see them here, but pins or “joints” are running perpendicular through holes in the “bones” and connecting them.

Tension strings will run through the fingers and holes, such as these to give the hand control.

Part Two: 3D Printing in the Product Development Process

Part Two: The Product Development Process

Where does 3D Printing fit into this process?

Define and Refine the Idea

Research and Design

Select and Purchase Materials

Create the product

Test the product and Market it

CAD Drawing

3D print the product

Product Manager

Design Engineer

Materials Engineer

Manufacturing Engineer

Quality Engineer

What does the acronym CAD stand for?

What is the importance of a sketch/drawing in the design process?

Answer Me!

CAD and Drawings

Part Two: The Product Development Process

Computer Aided Design (CAD)

• CAD allows for:
• Efficient design and optimization
• Saving time → Increase in productivity
• Improvements in accuracy
• Drawing and dimensioning
• Creation of complex multi-part assemblies

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TinkerCAD is a type of CAD software!

Part Two: The Product Development Process

Read Me!

Drawings and Dimensioning

With CAD comes another step, and that is DRAWING!

• Drawings are important when it is time to send your design to a manufacturer.
• They specify shape, size, materials, and how you will assemble the design (if there are multiple parts).
• You must include as many views as necessary to showcase each unique side of your design.
• These could include TOP, FRONT, and SIDE views.
• All parts necessary in building the design are dimensioned (labeled with a specific measurement).

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Drawings are cool because they serve as a universal language among engineers, meaning anyone can read and understand them!

Part Two: The Product Development Process

Drawing Activity

Part Two: The Product Development Process

Now it’s your turn to practice with some simple engineering drawings. Using the images on the left, decide what the top, front, and side views are of the design on the right! Drag these boxes to show your answer:

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Side

Front

Top

Spatial Intelligence & Multi-View Drawings: Your turn!

Part Two: The Product Development Process

Which isometric view to the far right match the top, front and side view?

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Part Three: It’s Your Turn to Design a Prosthetic

Pretend you are a design engineer building a prosthetic finger. How would you use the Engineering Design Process so that the finger meets the needs of your customer?

THINK:

What action would you take for each step of the process?

Click HERE for more information on the Engineering Design Process!

Your Prototype Design Constraints:

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• The maximum dimensions of your object are 10 cm x 10 cm.
• The height of your object should not exceed 2 cm.

1. Familiarize yourself with different types of E-NABLE prosthetics.
2. Gain an understanding of how the E-NABLE prosthetic fingers work.
3. Once you have an understanding, choose a finger you would be interested in designing to be a prosthetic, and follow the Engineering Design Process to effectively execute your idea.
4. Start by drawing a 1:1 scale sketch of your chosen prosthetic finger, and be sure to dimension the main parts of the finger (length, width, height).

Things to confirm when finished:

• Make sure there’s a TOP, FRONT, and SIDE view of the prosthetic finger.
• All parts are dimensioned.
5. Design your finger in TinkerCAD!
6. Compare your dimensions to the given Client dimensions and resize finger to meet Client needs.
7. Have fun and be creative!

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Your Task Today: Be a Design Engineer

Part Three: Design a Prosthetic

Different 3D Printed Prosthetics

Part Three: Design a Prosthetic

When 3D printing prosthetics, the possibilities are endless! E-Nable has designs for anything from a singular finger to an entire arm!

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These prosthetics all provide different levels of functionality, depending on what the client needs.

Observing 3D Printed Hands

Think About It!

Based on the observations made after watching the video, answer the following questions about this prosthetic hand:

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How does the prosthetic attach to the body?

How many parts, or “bones” of the finger, are there?

How many pins, or “joints”, are there in the fingers?

How do the joints work to provide function?

Part Three: Design a Prosthetic

Answer Me!

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Brainstorm and Plan

Answer Me!

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Part Three: Design a Prosthetic

The next step is for you to choose which finger you are going to design a prosthetic for.

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Then, based on your answers to the questions about the design of 3D printed hands, answer these same questions about a singular finger:

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• How many bones and joints are you going to include?
• How are you going to attach your finger to the client?

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Make a Drawing of your Prosthetic Finger of Choice

Insert Here!

Using what you learned from the engineering drawings in the introduction, make a sketch of your design. This sketch should be to scale (meaning it is the same size as your real prosthetic would be), and you should include the dimensions of three different parts of your finger, as well as three different views of your finger (top, front, and side).

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Part Three: Design a Prosthetic

Create your Design in TinkerCAD!

When designing, it’s important to take into consideration:

• Dimensions
• Material
• Cost
• Practicality
• Client’s interests

Use this video for a refresher on TinkerCAD!

Write down some of your ideas here:

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Part Three: Design a Prosthetic

Click here for advanced keyboard shortcuts and tips in TinkerCAD

Steps to Creating a TinkerCAD account

1. Go to tinkercad.com
2. Click “Join Now” in the upper right corner of the screen
3. Click on “create a personal account”
4. Sign up with either your personal email or google
5. Enter your credentials and follow any further instructions

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Now you have an account and are ready to start tinkering!

Watch this video for an example finger in TinkerCAD!

Applying Client Details

Part Three: Design a Prosthetic

Now that you have designed your prosthetic in TinkerCAD, it is time to fit it to a client! Choose a client to work on an let us know why you chose them!

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Client 1 has a remaining portion of their finger that is 21 mm long with a circumference of 18 mm. They work in computer science, and need a finger that will have enough dexterity and specificity to type on a computer and not hit the wrong keys.

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Client 2 has a remaining portion of their finger that is 23 mm long with a circumference of 20 mm. They work in construction and need a finger that will be strong enough to work with the rest of their hand when carrying heavy objects.

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Client 3 has a remaining portion of their finger that is 19 mm long with a circumference of 17 mm. They are an artist and need a finger that will be able to hold a pencil or paintbrush when they are working.

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Applying Client Details

Part Three: Design a Prosthetic

Insert Here!

Insert images of your finger designed in TinkerCAD here.

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Answer Here!

Provide the client you chose and the reason why you selected him/her.

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Want a 3D Printed Model of your Design?

Part Three: Design a Prosthetic

1. Select “Export” from the top right menu to reveal the screen shown to the right here.
2. Select “Download”, include “Everything in the design” and select “.STL” for 3D Print.

NOTE: You will not be able to open the .STL file unless you have special software installed on your computer.

• Attach the .STL file to an email and send it to your teacher.
• Teachers, please forward your students’ .STL files to Engineering Tomorrow at 3Dprint@engineeringtomorrow.org and provide us a summary listing of the files to print including: Teacher’s full name, school name & address, and the names of the students whose files you have forwarded to us for printing.
• Engineering Tomorrow will mail you the printed designs.

What do you think went well when completing this activity?

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Reflection

Answer Me!

Complete the mandatory 5-minute

Exit Ticket by clicking here!

What is something you would do differently if you were to do this again?

Continue to Explore

If you liked today’s breakout, you may be interested in these topics:

Types of Engineering Relevant to today’s 3D Printing breakout:

• Rapid Prototyping
• 3D Printing of COVID-19 PPE
• Other Materials: 3D Printing with Wood and Metal here and here
• Career in Biomedical Engineering
• Free CAD Programs for 3D Printing

• Materials Science
• Computer Science
• Mechanical Engineering
• Civil Engineering
• Mechatronics
• Biomedical Engineering