My final presentation for Biomedical Engineering Junior Design, Spring Quarter of 2009. Rose-Hulman\'s Junior Design program includes everything up to the point of manufacture, serving as an entry point for the four quarter sequence in which students undertake and complete their capstone project. I was lead development engineer of the foot subsystem, Tyler Kreipke lead the shaft subsystem, and Justin Druba lead the socket subsystem.

1. Adjustable, Low Cost, Trans-Tibial Prosthesis Paradigm Designs Kyle Harbison, Justin Druba, and Tyler Kreipke

2. Problem: Children in disadvantaged areas often lose their lower leg due to landmines Problem Statement: Develop a trans-tibial prosthesis that maintains an adaptable and abiding integrity while being able to be produced and maintained with limited resources. Background

3. Support normal forces associated with gait Adjust to account for user growth Be low cost Be maintainable in disadvantaged areas Feasibility Criteria

4. Modular approach resulted in designing three alternatives per subsystem Three Subsystems Socket – Connection to residual limb Shaft – Major length adjustability Foot – Accommodation towards varying terrain Preliminary Designs

5. Socket Preliminary Ideas Cinch Basket Brace Removable Padding Basket

6. Shaft Preliminary Ideas Slide ‘n’ Tight Threaded Leg Crutch Leg

7. Foot Preliminary Ideas Spring Foot Split Hoof Slider

8. Merit Criteria

9. Adjustability in terms of upper leg accommodation is achieved in this system User comfort is the key determining design aspect for this subsystem Neoprene coated nylon basket, steel brace components Socket Subsystem

10. Adjustability in terms of prosthetic height is achieved in this subsystem Achieves a range of 11 through 15.4 inches of adjustability Aluminum 2024 ShaftSubsystem

11. Polyoxymethylene – same material used in existing products Multi-axial stability over varying degrees of terrain Conservation of energy specifically targeted within heel dimensions Foot Subsystem

12. Final Assembly

13. Loading Calculation Length Calculation Engineering Calculations Shortest Length = 11.0” Longest Length = 15.4”

14. Stress Calculations Engineering Calculations Socket Support Beam Thickness (h) h>0.34”

15. Engineering Calculations Stress Calculations Foot Width (b) B>1.37”

16. Budget

17. Socket Subsystem: Create a more adjustable basket Shaft Subsystem: Use a different material for the inner shaft Foot Subsystem: Perform material tests on Delrin Further Considerations/Recommendations

18. Questions?