Overview of the Overview of the Prosthetic Arm ChallengeProsthetic Arm Challenge

2012-2013MESA USA National Engineering Design Competition

Prosthetic Arm Challenge Prosthetic Arm Challenge IntroductionIntroductionA classmate has recently lost part of

her arm below the elbow. She now needs a prosthesis that is low-cost and easily maintained that will allow her to complete daily tasks in school and at play.

What is a Prosthesis?What is a Prosthesis?A prosthesis is an artificial limb (an

artificial substitute) that replaces a missing leg or arm due to disease, accidents, or congenital defects.

Main types of artificial limbs:◦Transtibial prosthesis ◦Transfemoral prosthesis◦Transradial prosthesis (MESA Prosthetic Arm

Challenge)◦Transhumeral prosthesis

A U.S. soldier demonstrates table football with two transradial prosthetic limbs

i-limb ultra, by Touch Bionics, has five individually powered digits and went on sale in 2007 for $17,454

The Jaipur foot, a transtibial prosthesis, is readily available to impoverished nations and costs $35. In contrast, prosthetics in the U.S. cost from $5,000 to over $100,000.

Prostheses in the United States are made from materials such as plastic, metal (aluminum, steel, titanium), silicon, latex, and carbon fiber. These devices can also have robotics components.

Man builds himself bionic Man builds himself bionic handshandsSun Jifa lost both his hands when

a homemade blast fishing bomb exploded prematurely. Unable to afford the prosthetic limbs offered by a hospital, he created his own.◦ Source:

http://news.yahoo.com/photos/man-builds-himself-bionic-hands-slideshow/#crsl=%252Fphotos%252Fman-builds-himself-bionic-hands-slideshow%252Fbionic-hands-photo-1345045308.html

“I survived, but I had no hands,” he explained.

After the accident, Sun Jifa, 51, of Guanmashan, Jilin province in northern China desperately needed to work on his family farm, according to the Daily Mail.

Jifa spent eight years handcrafting prototypes before finally creating metal hands that could grip and hold.

“I couldn’t afford to buy the false hand the hospital wanted me to have, so I decided to make my own,” Jifa says.

The devices depend on a series of wires and pulleys inside, and are controlled by movements in his elbows.

“I made this from scrap metal for virtually nothing,” Jifa says.

Jifa says he will further develop the design for other disable people.

“There is no need to pay hospitals a fortune,” Jifa says.

MESA Advisors and MESA Advisors and ChallengeChallenge

MESA Advisor Shows Off Her Group’s Device

MESA Advisors from the USC Center utilize re-purposed materials to build a prosthetic arm device to pick up a ball and other objects.

Prosthetic Arm Challenge Prosthetic Arm Challenge OverviewOverviewThe MESA USA Prosthetic Arm Challenge involves the development of a low-cost prosthetic device to complete pre-defined tasks. The challenge has four components: Performance, Technical Paper, Academic Display and Oral Presentation.

Objective: Teams will build a low-cost prosthetic arm for use by a classmate who recently lost part of her arm below the elbow. The device should be designed to be low-cost and easily maintained and allow her to complete daily tasks in school and at play. The device must meet the criteria outlined in the rules and be designed to perform the pre-defined tasks.

Device Performance – 150 points◦Distance Accuracy Relay◦Object Relocation◦Dexterity (high school only)

Device Efficiency – 50 pointsTechnical Paper – 100 pointsAcademic Display – 100 pointsOral Presentation – 100 points

Challenge Performance Challenge Performance TasksTasks1. Distance Accuracy Relay: greatest

distance and accuracy achieved by tossing balls of different sizes into target containers at different distances

2. Object Relocation Task: greatest mass-to-time ratio achieved by placing objects of varying weights into a container

3. Dexterity Task: greatest number of bolts and nuts correctly placed and secured onto testing device

*Middle school devices will be judged on the first two tasks only.

General RulesGeneral RulesDevice must attach halfway between elbow and

wrist, and extend beyond real hand.Device must include hand mechanism (at least 2

fingers) and must open and close w/o assistance from opposite elbow, forearm or hand.◦ Hand mechanism must open at least 10 cm. ◦ Objects in each task MUST be grasped, taken hold of, or

grabbed on part of device that extends beyond hand (i.e. the “fingers” of device). Can NOT use any other part of device or parts of own hand, wrist, or arm to grasp, take hold of, or grab objects.

Device, including all parts of all configurations, cannot weigh more than 3 kg.

All parts and materials of the device cannot exceed $40 pre-tax price limit

Must complete and submit provided itemized budget sheet and attach receipts and/or online retail price print-outs to support prices listed.

Device cannot utilize team member’s wrist, hand, or fingers in any way.

Team will determine their method of immobilization and must demonstrate this for judges.

In addition, a latex glove will be placed over member’s CLOSED FIST before attaching device.

Parts may NOT be added, removed, replaced, or readjusted during trial; between trials is allowed.

Distance Accuracy Relay Distance Accuracy Relay HighlightsHighlightsTarget containers at three different distances

◦ Containers are Home Depot’s “Homer’s All-Purpose Buckets 2 meters from launch line 3.5 meters from launch line 5 meters from launch line

Relay objects are three different size balls 5 standard size tennis balls (≈ 2.5 inches) 5 vinyl kick balls (2 inches) 5 standard size ping pong balls (≈ 1.5 inches)

Diagram 2

Relay objects randomly placed in cardboard box

Top lid of an Office Depot Copy Paper 10 reams box

1 minute to prepare and demonstrate device, and to place device and box with Relay Objects anywhere on table.

When given start order, first designated team member enters Working Area, attaches device, and tosses as many of the SAME TYPE of balls.

Teams MUST toss all types of same balls before tossing subsequent types of same balls.

At least two team members MUST participate in the relay. One member must not toss more than two types of balls.

Only ONE of the balls may be grabbed at a time.

Only balls inside designated box may be used for tossing.

Trial will conclude:◦ At end of 90 seconds◦ When a member grabs more than one ball◦ When a member tosses wrong type of ball◦ When any part of member’s body including arm

and device crosses launch line when tossing ball◦ When target container is knocked overScore

Matrix2m

Target3.5m Target

5m Target

Tennis Ball 10 15 25Kick Ball 15 20 30Ping Pong Ball

25 30 40

Object Relocation Task Object Relocation Task HighlightsHighlightsObjects

1. Two – 20 ounce Dasani bottles of water2. Two – 1 liter Dasani bottles of water3. Two – 1 lb boxes of Crayola Modeling Clay4. Two – Master Lock 1500D 1 ⅞” Combination Locks5. Two – Quart size Ziploc bags with 200 Pennies6. Two – Spindle of 30 CD’s7. Two – 2 inch by 20 yard Rolls of Duct Tape8. Two – 4 oz. bottles of Elmer’s Glue All (white school glue)9. Two – Packages of 12 AA Energizer Batteries10. Two – Composition Notebooks, 100 pages, page size 7.5” L x 9.5” W11. Two – 1 lb Box of Grip-Rite Nails any size, box dimensions approximately 2” H x 4.75” W x

3.5” L12. Two – Packs of 100 3” x 5” Index Cards13. Two – Spiral Bound 3 Subject Notebooks, 120 pages, size 10.5” L x 8” W14. Two – Rolls of  1” x 60 yards masking tape15. Two – 1 pound bags of pony beads (approximately 2000 beads)

10 of the 15 item groups will be selected on day of competition

1 minute to prepare, attach, and demonstrate device, and to place container in one “Container Area”.

76 cm

50 cm50 cm

Diagram 3

83 cm

At end of 1 minute or when device is prepared, attached and ready, designated team member will stand outside of Working Area.

1 ½ minutes (90 seconds) to complete task.At least 5 different item types MUST be

place in container or trial will be declared a mistrial.

Team may call end of trial before 1 ½ minutes have passed by calling out “done”.

Any item held by device when time is called will not be counted towards total mass of container.

Dexterity Task HighlightsDexterity Task HighlightsFor high school teams ONLYTesting device made from

two 1 foot x 6 inch x 1 inch boards attached perpendicular to each other.

1’ Length

6” HeightA B C

3”

FRONT VIEW

Diagram 6

Vertical board with three pre-drilled holes 3 inches from edge and 3 inches from top

Hole “A” = 6.9mm Metric Drill (US-17/64) Hole “B” = 10.0mm Metric Drill (US-27/64) Hole “C” = 14.2mm Metric Drill (US-35/64)

Dexterity Materials include: Hole “A” = 8mm x 1.25mm hex bolt and nut, and 13

mm wrench Hole “B” = 12mm x 1.5mm hex bolt and nut, and

19mm wrench Hole “C” = 16mm x 2.0mm hex bolt and nut, and

24mm wrench

1 minute to prepare, attach, and demonstrate device, and to prepare “Testing Area” and dexterity materials.◦ Testing Device can be placed in either Testing Area (50 cm

square).◦ Dexterity materials placed outside of Testing Area.

At end of 1 minute or when device is prepared, attached and ready, designated team member will stand outside of Working Area.

2 minutes to complete task.Member may sit or stand and may move chair

and/or stand anywhere in Working Area.

Task is as follows:◦ Grab and place hex bolt into corresponding pre-drilled holes.

May hold head of hex bolt with non-prosthetic hand ONLY. May NOT twist or screw in any way or trial will stop and be declared a mistrial.

◦ Grab corresponding hex nut and place onto bolt.◦ Grab corresponding wrench and screw hex nut onto bolt.◦ Repeat for all three hex bolt and nut sets.

May choose in what order each bolt/nut set is secured but must place a nut on a bolt before attempting another. Once all three nuts have been placed on bolts, may re-visit any bolt/nut set to score more points.

Each hex bolt will have a marking every 0.5 cm from base of bolt head.

RemindersRemindersSafety first: Since transradial prosthesis

will be attached to student’s arm, please keep safety in mind at all times.

Stay within all the parameters of the project.

Research, brainstorm, build, test, record, revise, build, test, record, revise, build, test,…◦ Use the Engineering Design Process

READ ALL THE RULES!!!

Activity 1 – Relocating ObjectsActivity 1 – Relocating ObjectsObjective

◦ Design, build and operate a transradial prosthesis from given supplies to grab various size objects one a time and release them into a container

Supplies per group◦ 2 sheets of card stock paper◦ 5 feet of string◦ 9 straws◦ 14 craft sticks◦ 3 beads◦ Activity Sheet

Activity 1 InstructionsActivity 1 Instructions Using the given supplies, design and build a transradial prosthesis. The

prosthetic arm should be attached half way between the elbow and wrist and should extend beyond the real hand.◦ Device MUST have hand mechanism and MUST open and close.◦ Can NOT use opposite elbow, forearm or hand OR real hand to

operate or control the prosthetic arm.Creating One Finger with Two Joints Cut one craft stick into three equal pieces. Cut two pieces of straw slightly shorter than the pieces of sticks. Glue one piece of straw to one piece of stick. Put the glue on the stick

and not the straw or the straw may melt. Do this for a total of TWO straw/stick segments.

Glue the two stick segments onto a full straw. The sticks should be sandwiched between the straws now. Leave a small space in between each segment, so that bending is possible at the joint.

Glue full straw’s excess onto a full length craft stick. Leave a small space between the full length craft stick and the first segment, so that bending is possible at the joint.

Activity 1 Instructions continuedActivity 1 Instructions continued Glue one more straw segment onto the top of the full length craft

stick in line with the other two segments.  Tie a bead onto the end of piece of string. Use the bamboo skewer

to thread the other end of the string through the first short straw segment and through the two other short straw segments.

Wrap each segment with tape to reinforce the glue. Pre-bend the finger at each joint.

Creating Arm and Operation Using the remaining supplies, create two more fingers, the arm and

the operation of the fingers.

Testing Attach the transradial prosthesis and pick up the different objects

from a table one at a time and release them into the container/box.

Activity 2 – Tossing Balls into Activity 2 – Tossing Balls into TargetsTargetsObjective

◦ Design, build and operate a transradial prosthesis from any of given supplies to toss various balls one a time into cups at different distances.

Supplies per groupo 5 – sheets of 9” x 12”

construction papero 3 feet of masking tapeo 5 index cardso 1 pair of scissorso 2 plastic spoonso 3 feet of stringo 5 straws

o 10 craft stickso 5 – 3 ½” rubber bandso 10 small paper clipso 10 large paper clipso 10 fasteners o Activity Sheet

Activity 2 InstructionsActivity 2 Instructions1. Using any of the given supplies, design and build a

transradial prosthesis. The prosthetic arm should be attached half way between the elbow and wrist and should extend beyond the real hand. Device MUST have hand mechanism and MUST open and close. Can NOT use opposite elbow, forearm or hand OR real hand to

operate or control prosthetic arm.2. Place cups 1 foot, 2 feet, and 3 feet from launch

line. No part of team member or device may cross launch line.

3. Arrange different balls from smallest to largest.4. Attach transradial prosthesis and grab and toss

one ball at a time; toss same type of ball before tossing subsequent type of same ball.

Ben LouieUSC MESAblouie@usc.edu

Questions?Questions?