D ESIGN OF AN A NKLE F OOT O RTHOTIC Christopher Sullivan.

DESIGN OF AN ANKLE FOOT ORTHOTICChristopher Sullivan

OUTLINE

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

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

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

THE GAIT CYCLE

Over the years the Gait Cycle has been meticulously measured.

     Periods Initial

Double-Limb Support

Single-Limb

Stance

Second Double-Limb

Support

Initial Swing 

Mid-Swing 

Terminal Swing

Foot Strike

Opposite Toe-Off

Opposite Foot Strike

Toe-Off Foot Clearanc

e

Tibia Vertical

Foot Strike

Stance Swing

% of Cycle 0% 62% 100%

2-D KINEMATICS OF LEG DURING WALKING

0 20 40 60 80 100

-30

-10

10

30

Plantar Dorsi Flexion θF

Angle DataOpposite Toe-OffOpposite Foot StrikeToe-Off

% of Cycle

Angle

(D

igre

e)

0 20 40 60 80 1000

20

40

60

Hip Flexion Extension θHAngle DataOpposite Toe-OffOpposite Foot Strike

% of Cycle

Angle

(Dig

rees)

0 20 40 60 80 1000

10

20

30

Pelvic Tilt θP

Angle DataOpposite Toe-OffOpposite Foot StrikeToe-Off

% of Cycle

Angle

(D

igre

e)

0 20 40 60 80 1000

20

40

60

Knee Flexion-Extension θK

Angle Data

Opposite Toe-Off

% of Cycle

Angle

(D

igre

e)

Svensson W, Holmberg U. Ankle-Foot-Orthosis Control in Inclinations and Stairs. 2008 21-24 Sept. 2008. p 301-306.

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

2-D KINEMATICS OF LEG DURING WALKING

Free Body Diagram Created

Simple Quasistatic Analysis Done

Dynamic Analysis Still needs to be Done

0 20 40 60 80 100

-75

-55

-35

-15

5

Angle of Foot to Ground θBC

Angle Data

Opposite Toe-Off

Opposite Foot Strike

Toe-Off

% of Cycle

Angle

(D

egre

e)

0 20 40 60 80 1000.00

0.20

0.40

0.60

0.80

1.00Torque at the Ankle TR

Torque Data

Opposite Toe-Off

Opposite Foot Strike

Toe-Off

% of Cycle

Torq

ue (

Nm

)

B

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.

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

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

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.

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.

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.

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.

ACTUATOR SELECTION

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

ACTUATOR SELECTION

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

ACTUATOR SELECTION

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

NEXT STEPS

Before Design work can truly commence Interviews must be held A dynamic model must be created Proof of concepts prototypes

TIME LINE WINTER SPRING (2010-2011)

Goals Initial Literature

Search Begun Finish Literature

Search Finish and present

Thesis Proposal Modeling of the Foot

Course LoadWinter ACT System Dynamics Rapid PrototypingSpring Thermal Fluids Lab 2 Intro To Biomaterials Dynamics Of

Machinery System Modeling Comp Imp FEM

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

TIME LINE FALL (2011)

Goals Finish Building AFO Bench Testing Writing Thesis

Course Load Control Systems Senior Design 1 Math 1

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

TIME LINE SPRING (2012)

Goals Finish Clinical

Testing Finish Writing Thesis Thesis Defense

Course Load Advanced Control

Systems

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

IMPORTANT MILE STONES

Getting Approval to talk to patients Interviews

Design Reviews Presentation

Bench Testing Clinical Testing Approval

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

QUESTIONS?

REFERENCES1. Silberstein, N. (2008, November 2). Foot Drop. Retrieved from Pt Products Online: http://www.ptproductsonline.com/issues/articles/2008-

11_02.asp

2. 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

3. Roşca, I. C., & Radu, C. (2008, April 24-26 ). On the Design of the Analitycal Ankle – Foot Model . 6th International DAAAM Baltic Conference .

4. Sutherland DH, Olshen R, Cooper L, Woo SL. The development of mature gait. J Bone Joint Surg Am 1980;62(3):336-53.

5. Whittle MW. Clinical gait analysis: A review. Human Movement Science 1996;15(3):369-387.

6. Pandy MG. Models for understanding the dynamics of human walking 1987.

7. Pandy MG, Berme N. Synthesis of human walking: A planar model for single support. Journal of Biomechanics 1988;21(12):1053-1060.

8. Vaughan CL, Davis BL, O'Connor JC. Dynamics of human gait. Champaign, Ill.: Human Kinetics Publishers; 1992.

9. Prefabricated Ankle-Foot Orthoses. (n.d.). Retrieved from ANKLE-FOOT ORTHOSIS: http://www.orthomerica.com/products/anklefoot/ankle_foot.htm

10. 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.

11. Contraindications for Use of the NESS L300 Foot Drop System. (2010). Retrieved from Bioness: http://www.bioness.com/Canada_-_English/Contraindications.php

12. 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.

13. Svensson W, Holmberg U. Ankle-Foot-Orthosis Control in Inclinations and Stairs. 2008 21-24 Sept. 2008. p 301-306.

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

17. 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.

18. Tavakoli M, Marques L, de Almeida AT. A comparison study on Pneumatic Muscles and electrical motors. 2009 22-25 Feb. 2009. p 1590-1594.

19. 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.

20. Sauer P, Kozłowski K, Morita Y, Ukai H. Ankle Robot for People with Drop Foot – Case Study.443-452.

21. Blaya JA, Herr H. Adaptive control of a variable-impedance ankle-foot orthosis to assist drop-foot gait. IEEE Trans Neural Syst Rehabil Eng 2004;12(1):24-31.

22. Chu TT. Biomechanics of ankle-foot orthoses: past, present, and future. Top Stroke Rehabil 2001;7(4):19-28.

23. 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.