Design of an Ankle Foot Orthotic

1. Design of an Ankle Foot Orthotic Christopher Sullivan

2. Outline • What is Foot Drop? • Overview of gait cycle • Different kinds of existing AFOs • Actuator Selection • Timeline • Budget

3. Why do People Need Ankle Foot Orthotics? • Foot Drop • inability to Dorsiflex the foot during the Gait Cycle • Foot Drop is a Symptom associated with: • List conditions from next slide here Figure 1 http://sports.jrank.org/article_images/sports.jrank.org/dorsiflexion.1.jpg

4. Who does Drop Foot Effect? • Foot Drop is a lasting symptom to a variety of neurological conditions. • Stroke • Cerebral Palsy • Multiple Sclerosis • Polio • Direct injury to the Peroneal Nerve Figure 2 http://upload.wikimedia.org/wikipedia/commons/9/9d/Gray832.png

5. The Gait Cycle Stance Swing • Over the years the Gait Cycle has been meticulously measured. Initial Double-Limb Support Terminal Swing Second Double-Limb Support Mid-Swing Single-Limb Stance Initial Swing Periods Foot Strike Opposite Toe-Off Opposite Foot Strike Tibia Vertical Foot Clearance Foot Strike Toe-Off % of Cycle 62% 0% 100%

6. 2-D kinematics of leg during walking • Svensson W, Holmberg U. Ankle-Foot-Orthosis Control in Inclinations and Stairs. 2008 21-24 Sept. 2008. p 301-306.

7. 2-D kinematics of leg during walking θP= Angle of the Pelvis relative to the ground θH=Angle of the Upper Leg relative to the Pelvis θN=Angle of the Lower Leg relative to the Upper Leg θA= Angle of the Ankle relative to the Lower Leg B

8. 2-D kinematics of leg during walking • Free Body Diagram Created • Simple Quasistatic Analysis Done • Dynamic Analysis Still needs to be Done B

9. What is an Ankle Foot Orthotic? Commercially Available • Hard Plastic AFO • Electrical Stimulation Recently investigated • i-AFO • Variable Dampening AFO for Inclined Surfaces • AFO with Air Muscles • Pneumatic Power Harvesting AFO • An orthopedic brace meant to repaired lost function in the foot and ankle.

10. Hard Plastic AFO • Passive support of the Foot • Molded to fit patient’s leg • Rigidity can cause problems • Prefabricated Ankle-Foot Orthosis. (n.d.). Retrieved from ANKLE-FOOT ORTHOSIS: http://www.orthomerica.com/products/anklefoot/ankle_foot.htm

11. Electrical Stimulation • Bioness • Stimulates the Peroneal Nerve • Expensive • Unable to use if you have • Pacemaker • Heart Conditions • Recent fracture or dislocation • peroneal nerve location • Silberstein, N. (2008, November 2). Foot Drop. Retrieved from Pt Products Online: http://www.ptproductsonline.com/issues/articles/2008-11_02.asp

12. Variable Dampening AFO for Inclined Surfaces • Created in 2008 at Halmstad University in Sweden • Uses Magneto Rheological Damper • Very Unique • Too bulky to fit in shoe • The power supply is never specified • Svensson W, Holmberg U. Ankle-Foot-Orthosis Control in Inclinations and Stairs. 2008 21-24 Sept. 2008. p 301-306.

13. i-AFO • Constructed in 2010 at Yamagata University in Japan • Uses Rotary braking system • Untethered • Too bulky to fit in shoe • Kikuchi T, Tanida S, Otsuki K, Yasuda T, Furusho JYM. Development of third-generation intelligently Controllable ankle-foot orthosis with compact MR fluid brake T2 - Robotics and Automation (ICRA), 2010 IEEE International Conference on. Robotics and Automation (ICRA), 2010 IEEE International Conference on 2010.

14. AFO with Air Muscles • Created in 2005 at the University of Michigan • Uses Air Muscles to produce Plantarflexion • Too bulky to fit in shoe Tethered to an external air supply • Gordon KE, Sawicki GS, Ferris DP. Mechanical performance of artificial pneumatic muscles to power an ankle-foot orthosis. Journal of Biomechanics 2006;39(10):1832-1841.

15. Pneumatic Power Harvesting AFO • Created in 2009 at University of Illinois at Urbana-Champaign • Used a simple Pneumatic Linear Actuator • Generated its own power • Too bulky to fit in shoe • Chin R, Hsiao-Wecksler E, Loth E, Kogler G, Manwaring S, Tyson S, Shorter K, Gilmer J. A pneumatic power harvesting ankle-foot orthosis to prevent foot-drop. Journal of NeuroEngineering and Rehabilitation 2009;6(1):1-11.

16. Actuator Selection • Gomis-Bellmunt O, Campanile LF. Actuator Design Analysis. Design Rules for Actuators in Active Mechanical Systems: Springer London; 2010. p 29-78.

17. Actuator Selection • Gomis-Bellmunt O, Campanile LF. Actuator Design Analysis. Design Rules for Actuators in Active Mechanical Systems: Springer London; 2010. p 29-78.

18. Actuator Selection • Gomis-Bellmunt O, Campanile LF. Actuator Design Analysis. Design Rules for Actuators in Active Mechanical Systems: Springer London; 2010. p 29-78.

19. Next Steps • Before Design work can truly commence • Interviews must be held • A dynamic model must be created • Proof of concepts prototypes

20. Time Line Winter Spring (2010-2011) Goals • Initial Literature Search Begun • Finish Literature Search • Finish and present Thesis Proposal • Modeling of the Foot Course Load Winter • ACT • System Dynamics • Rapid Prototyping Spring • Thermal Fluids Lab 2 • Intro To Biomaterials • Dynamics Of Machinery • System Modeling • Comp Imp FEM

21. Time Line Summer (2011) Goals • Co-Op working on project • Interviews • Finish Modeling the Foot • Proof of Concept prototypes created • Systems level design • Detailed Design • Building AFO Started • Writing Thesis Co-op • 40 hr/wk

22. Time Line Fall (2011) Goals • Finish Building AFO • Bench Testing • Writing Thesis Course Load • Control Systems • Senior Design 1 • Math 1

23. Time Line Winter (2011-2012) Goals • Finish Bench Testing • Clinical Testing • Compile Work • Writing Thesis • Submit paper to IMECE or SBC Course Load • Inter. Control Systems • Senior Design 2 • Math 2

24. Time Line Spring (2012) Goals • Finish Clinical Testing • Finish Writing Thesis • Thesis Defense Course Load • Advanced Control Systems

25. Budget Part Time Work • 10 hr/wk for 3 qtrs Full Time Summer Co-Op • 40 hr/wk Prototype • $1000 for parts and testing supplies

26. Important Mile Stones • Getting Approval to talk to patients • Interviews • Design Reviews • Presentation • Bench Testing • Clinical Testing Approval

27. Summary • The goal of this project will be to create an Ankle Foot Orthotic • The difference between our project and any of the mentioned projects, is the way that the problem will be attacked

28. Questions?

29. References • Silberstein, N. (2008, November 2). Foot Drop. Retrieved from Pt Products Online: http://www.ptproductsonline.com/issues/articles/2008-11_02.asp • New Device Helps Stroke Patients suffering from 'foot drop'. (2010, September 17). Retrieved from Healthlink: . http://www.nwcn.com/news/health/New-device-helps-stroke-patients-suffering-from-foot-drop-103150749.html • Roşca, I. C., & Radu, C. (2008, April 24-26 ). On the Design of the Analitycal Ankle – Foot Model . 6th International DAAAM Baltic Conference . • Sutherland DH, Olshen R, Cooper L, Woo SL. The development of mature gait. J Bone Joint Surg Am 1980;62(3):336-53. • Whittle MW. Clinical gait analysis: A review. Human Movement Science 1996;15(3):369-387. • Pandy MG. Models for understanding the dynamics of human walking 1987. • Pandy MG, Berme N. Synthesis of human walking: A planar model for single support. Journal of Biomechanics 1988;21(12):1053-1060. • Vaughan CL, Davis BL, O'Connor JC. Dynamics of human gait. Champaign, Ill.: Human Kinetics Publishers; 1992. • Prefabricated Ankle-Foot Orthoses. (n.d.). Retrieved from ANKLE-FOOT ORTHOSIS: http://www.orthomerica.com/products/anklefoot/ankle_foot.htm • Sohn RH, Park SW, Hwang SH, Ko AR, Lee YH, Lee SH, Ryu KH, Kim YH. A Potable System for Foot-Drop Correction using Electrical Stimulation.259-260. • Contraindications for Use of the NESS L300 Foot Drop System. (2010). Retrieved from Bioness: http://www.bioness.com/Canada_-_English/Contraindications.php • Kikuchi T, Tanida S, Otsuki K, Yasuda T, Furusho JYM. Development of third-generation intelligently Controllable ankle-foot orthosis with compact MR fluid brake T2 - Robotics and Automation (ICRA), 2010 IEEE International Conference on. Robotics and Automation (ICRA), 2010 IEEE International Conference on 2010. • Svensson W, Holmberg U. Ankle-Foot-Orthosis Control in Inclinations and Stairs. 2008 21-24 Sept. 2008. p 301-306. • Gordon KE, Sawicki GS, Ferris DP. Mechanical performance of artificial pneumatic muscles to power an ankle-foot orthosis. Journal of Biomechanics 2006;39(10):1832-1841. • Chin R, Hsiao-Wecksler E, Loth E, Kogler G, Manwaring S, Tyson S, Shorter K, Gilmer J. A pneumatic power harvesting ankle-foot orthosis to prevent foot-drop. Journal of NeuroEngineering and Rehabilitation 2009;6(1):1-11. • Gomis-Bellmunt O, Campanile LF. Actuator Design Analysis. Design Rules for Actuators in Active Mechanical Systems: Springer London; 2010. p 29-78. • Huber, E. J, Fleck, A. N, Ashby, F. M. The Selection of Mechanical Actuators Based on Performance Indices. London, Royaume-uni: Royal Society of London; 1997. 21 p. • Tavakoli M, Marques L, de Almeida AT. A comparison study on Pneumatic Muscles and electrical motors. 2009 22-25 Feb. 2009. p 1590-1594. • Tsagarakis N, Caldwell DGY. Improved modeling and assessment of pneumatic muscle actuators T2 - Robotics and Automation, 2000. Proceedings. ICRA '00. IEEE International Conference on. Robotics and Automation, 2000. Proceedings. ICRA '00. IEEE International Conference on 2004. • Sauer P, Kozłowski K, Morita Y, Ukai H. Ankle Robot for People with Drop Foot – Case Study.443-452. • Blaya JA, Herr H. Adaptive control of a variable-impedance ankle-foot orthosis to assist drop-foot gait. IEEE Trans Neural SystRehabilEng 2004;12(1):24-31. • Chu TT. Biomechanics of ankle-foot orthoses: past, present, and future. Top Stroke Rehabil 2001;7(4):19-28. • Ohata K, Yasui T, Tsuboyama T, Ichihashi N. Effects of an ankle-foot orthosis with oil damper on muscle activity in adults after stroke. Gait Posture. Volume 33. England: 2010 Elsevier B.V; 2011. p 102-7.