Final presentation

1. Pediatric Prosthetic Arm
Group 17
Nabeel Chowdhury, Seul Ah Kim, Dah Som Kim

2. • Children need a prosthesis from an early age to develop motor
skills and so that a device will integrate into their social identity
• Currently the market is saturated with upper limb prosthetics
aimed at adults.
• The majority of prosthetics that children have access to have
little functionality
The Need

3. • We aim to make an affirdable lightweight, durable, and
waterproof myoelectric transradial prosthetic actuated by a
mckibben air muscle.
• This project aims to deliver a proof of concept of the air muscle
Scope

4. Design Specifications

5. Overview of design-Air Muscle Diagram

6. • Mckibben, the inventor of the muscle, used this
as an orthotic allowing for a pinch grip
• The shadow arm uses air muscles to
make a highly dexterous hand
• Vanderbilt used pneumatics to make
a fully gas powered trans-humeral prosthetic
Feasibility-use of pneumatics
http://edge.rit.edu/edge/P14253/public/Additional%
20research/Shadow%20hand%
20HQ/shadow_robot_company_hand_c5_claw_back.jpg

7. • Our batteries have a capacity of 180mAh and the average consumption is
150mA.
• Assuming average current consumption is 10% maximum and 90% rest,
• This is much lower than our specifications and means we will either need a
larger battery or a method that uses less power.
Feasibility-Battery Life

8. • Design specification ME03: total weight of the prosthetic arm should not
exceed 2.5 kg.
• Total weight = weights of the casing and internal components.
• The casing, which includes hand, lower arm, and socket, weighs
212.5g in total.
• The internal components, including solenoid valve, wires, microchips,
air muscle, and metal adaptors weighs 489.92g in total.
• Note that human hand weighs about 400g, and our hand weighs less than
212.5g.
Feasibility-Weight

9. • The prosthetic exhibited
ability to contract farther
with greater weights.
• This appears to be a distinct
characteristic of air muscles
which is similar to the way a
real muscle would behave
• The amount of mass the air
muscle could pull is well
above our specification.
Feasibility-Strength

10. Specifics-Casing

11. Specifics-Hand

12. Specifics of design-Circuit Diagram

13. Specifics of design-Program Flowchart

14. Specifics of design-Solenoid
http://www.solenoidsolutionsinc.com/images/threeWay.gif

15. Specifics-Air Muscle

16. • The prosthetic can pull a large amount of mass meaning it has a
large grip force
• The parts of the device are easy to remove and exchange
• The device is water resistant in heavy rain
Conclusion-Successes

17. • The device is heavier than the previous version
• The device is not fully waterproof
• The socket will come off after a drop, but the device doesn’t
break pro and a con
• The adaptor with all of the brass fittings was too long to fit
inside the device, but it would fit if the patient grew.
Conclusion-Failures

18. • Custom machining the brass fittings out of aluminum
• reduces weight and length
• Smaller/Refillable CO2
• Internal Charging for batteries
• Using a servo valve
• reduces weight, size, and power consumption
• Using a pressure regulator
• eliminates the need for a needle valve
• Brushing on epoxy to the surface of the 3D print or sealing the casing with a stronger rubber than hot
glue.
• seals all of the layers of the print
• Using inductive charging
• the qi standard allows for a universal charger and it is waterproof
• Using solar power to keep the battery alive longer
Future Directions

19. Budget

20. Design Specifications

21. Questions?

22. Prototype Demonstrations-Video

23. Prototype Demonstration-Length Change

24. Prototype Demonstration-Casing and Wrist