1. Multi Surface Sensing Ankle foot Orthotic

2. Put a slide here describing your overall project goals, and what you’re focusing on for this talk

3. Add a slide here with an overview of foot drop, and pictures of a couple of typical AFOs Might not be a bad idea to show a typical ankle flexion plot through the gait cycle, along with Walking Stick Man

4. Interviews at NAZ 10 patients have been interviewed All of them were stroke victims, with the exception of one with MS. All of the patients were elderly, and lived with the assistance of a spouse or nurse. All Patients had AFOs for more than 6 months

5. Interviews at NAZ Major Takeaways Foot Drop has many other compound symptoms. Rolling of the ankle Clenching of the toes Most AFOs are designed with level surface conditions in mind. Patients complained about walking down stairs, and ramps Patients complained about the weight of the AFO. Patients also complained about the bulkiness of their braces. These AFOs are the only things that lets these patients walk

6. Interviews with Rochester Orthopedics Lab Why the braces where bulky? Rolling ankle, distribution of force The supplier of numerous commercially available AFOs Ossur Becker Dynamic Walk Otto Bock Allard Tamarack Most Commercially available AFOs are meant for patients with just Drop Foot Figure 1. Dynamic Walk Single

7. Interview with Dr. Barbano Patients at Rochester General are under 6 months Still dealing with many other problems caused by the stroke Most Patients are given a solid AFO before they are released At the hospital it is not common to see these other kinds of braces The patents are referred to other clinics in the area, to help them with physical therapy

8. Defining the target patient and general needs Should be based off of the patents observed at NAZ They seem to be the patents that we will end up have to test it on Should be well into the recovery after their stroke They should be able to supply feedback Would not be a candidate for a commercially available AFO Must use a kind of jointed brace There gait could also be impaired by rolling of the ankle or toe curling Source: http://www.tamarackhti.com/joints/dorsiflexion.asp Figure 2. Tamarack joint

9. Customer needs Functionality Lifts foot up at appropriate time Sit to stand Stairs Inclined surface level surface Constraints Fits into a shoe Ease of access Adjustability Light Weight Portable Inexpensive Able to be used on both sides of the body Safety Durability/fatigue life Biocompatible surface Able to be cleaned/sterilized

10. Metrics MetricUnitsTest Importanc e (1-4) Ref Sit to Stand 70 to 85 deg Detects and Allows for adequate motion of the ankle while attempting to stand from a seated position 4 A Motion Control of a Robotic Walker for Continuous Assistance during Standing, Walking and Seating Operation Stairs Accent 82 to 58 deg Detects and Allows for freedom of the ankle so the patient could walk with successive foot motion up and down a flight of stairs 3 Ankle-Foot-Orthosis Control in Inclinations and Stairs Stairs Decent 82 to 45 deg Detects and Allows for freedom of the ankle so the patient could walk with successive foot motion up and down a flight of stairs 3 Ankle-Foot-Orthosis Control in Inclinations and Stairs Inclined surface accent 82 to 46 deg Detects and Allows for motion of the foot during decent or assent of a ramp 2 Ankle-Foot-Orthosis Control in Inclinations and Stairs Inclined surface decent 60 to 80 deg Detects and Allows for motion of the foot during decent or assent of a ramp 2 Ankle-Foot-Orthosis Control in Inclinations and Stairs Level Surface 75 to 45 deg Patient does not drag there foot on the ground. 1

11. Constraints MetricUnitsTest Importanc e (1-7) Fits into a shoeBinary Attempt to fit into a shoe possibly using a floppy (find a better word) foot 2 Ease of access10 Min Attempt to put on with one hand, time results document relative range of motion necessary to complete task 3 Adjustabilitycm What rand of body types can this AFO fit? 5 Light weight <1 kg Use hard plastic AFO as benchmark for weight 4 Portable 10hr Operation length 1 Inexpensive <1000$ BOM 6 Able to be used on both sides of the body Binary Can it be used on both sides of the body? 7

12. Safety MetricUnitsTest Importanc e (1-3) Durability/ Fatigue Life Cycles Fatigue test the AFO (or at least identify weakest component and test that) 3 Biocompatible surface Binary Documentation of material must support claim 2 Able to be Cleaned/Sterilized Binary Documentation of material must support claim 1

13. Functional block diagram

14. Initial Design Components StrapsCommentsPowerCommentsPassive ElementsComments Velcro Cheap, has a short lifespan, trouble getting proper contact Li-ion High Energy Density, 1200 cycles PEEK rods Flexible polymer Rods Plastic ratchet Relatively more expensive longer life time, solid connection NiH2 lower energy density, 20000 cycles Carbon Fiber Can be used for a leaf Spring Special Sock Similar to amputee patients Passive Run until material Failure Rotary Dampers Geometry based on geometry the brace holds itself onto the patient Pressurized air Pressurizing air on demand would require a battery Metal Springs Knee brace uses the knee as an anchor hold the brace on the leg Mechanical wound To run like a clock (not a very likely choice) Bushing tilt Joint Half of a skate board Truck Active ElementsCommentsSensorsCommentsMicrocontrollersComments Linear Actuator Bulky ADXL345 Accelerometer Accelerometers are hard to use, drift Arduino Some are rather Large, but it has a good development community Electric Motor Requires gear box Sharp IR Range Finder No drift, but could hit pants Teensy Small same kind of Dev. Community as Arduino Piezoelectric Linear Actuator Hold position at zero power Seeeduino Smaller Arduino bigger than the Teensy Stepper motor Easy location Variable Rotary Dampers Hard to find

15. Initial Design Combinations Design #Name Add on? Brace MaterialStrapsPower Passive ElementsActive ElementsComments 1Variable PEEK rod AFOno Carbon FiberVelcroLI-ionPeek rods Piezoelectric Linear Actuator Pulls Peek rod into it changing Spring initial Loading 2 Adjustable Plantar Stop add-onYesnoneLi-ionMetal SpringsLinear Actuator Changes the location on the Back Stop 3 Variable PEEK rod AFO With Geo Fitno Carbon FiberGeometryLi-ionPeek rods Piezoelectric Linear Actuator Pulls Peek rod into it changing Spring initial Loading Uses Geometry of Spring to Hold leg in place 4N/Ano Carbon FiberVelcroLI-ionBushing Tilt JointLinear Actuator Has a variable axis Moved by linear actuator 5Rotary Damper AFOyesnoneLi-ionRotary Dampers Rotary damper added on though a variable transmission, dampening used to stop foot 6 Variable Rotary Damper AFOno Polyethyle neVelcroLI-ion Variable Rotary damper change damping to stop foot when needed should be paired with a way to move the foot 7Stripper Motors AFOno Carbon FiberVelcroLI-ionTorsion SpringStepper Motor Holds the foot in position at proper time 8 Vareable Carbon Fiber Leaf Spring AFOno Carbon FiberVelcroLI-ionCarbon FiberLinear Actuator Carbon Fiber used as leaf spring in back of AFO with movable interfering piece, much like prostatic foot design, but variable Figure 3. Variable peek Rod Figure 4. Variable peek Rod Geo Fit

16. Initial Design Matrix Criteria12345678AFO Fits into a shoe +0+----+0 Ease of access 00+000000 Adjustability of overall foot position ++++0+++0 Variable axis ++++---+0 Portable battery life/ battery dead? -0------0 Inexpensive --------0 Feasibility (back stop change is base line) -0------+ Level Surface +++000++0 Can Be adjusted to Stairs ++++++++0 Can Be adjusted to Ramps ++++++++0 Safety features? 000-0--00 Durability --------0 Able to be cleaned --------0 Total +657423461 Total -535778850 Sum122-3-5 -411 Design #NameConcerns 1Variable PEEK rod AFO LEG actuators can take different actuation rods 2Adjustable Plantar Stop add-on Linear actuator to hold plantar stop 3Variable PEEK rod AFO With Geo Fit Is geo fit possible? And can it be used on all kinds of patients 8Vareable Carbon Fiber Leaf Spring AFO Look into complete mechanically driven brace, i.e. no control system

17. Adjustable Plantar Stop Attaches to the back of existing AFO Two individually adjustable back stops attached to rotating joint Linear actuator offset to the side It rotates the back stop in and out of position But structurally isn't what is inevitably holding the foot Figure 5. Y rocker AFO

18. Issues with design It adds weight Make the Brace Lighter Attaching to the back of an existing AFO Adhesive Vacuum Use existing backstop Velcro Actuation Piezoelectric Linear actuator Knowing the Ground Accelerometer IR Range Finder Figure 6. Shell Stopping AFO

19. Carbon Fiber Brace Breaks the project up into 2 areas Bulk reduction in weight and size will help get patients excited about their brace Spring properties of carbon fiber Figure 7. Carbon Fiber

20. Steps to Carbon Fiber Brace Working with Rochester Orthotics Lab Using old molds General facilities Sitting in on Composites Figure out how the carbon fiber will react Build brace for project

21. Piezoelectric Linear actuator Small Light weight Linear actuators 23g 22 x 10 x 19 mm Holding Force 6.5N Stall Force 7N Source: http://www.piezomotor.se/uploaded/LL1011_150010_00.pdf Figure 8. Piezoelectric Actuator

22. Accelerometers Require a lot of data analysis Drift in integration accuracy Measuring many different things Most of which I am uninterested in Most of which is very noise

23. IR Rang Finder Initial Look into expected data Source: http://www.technologicalarts.com/myfiles/data/gp2d120.pdf Figure 9. Sharp IR sensors Figure 10. Sharp IR sensors Technical Drawing

25. Level Ground

26. Descending Stairs

27. Distance Detected Level Ground vs. Descending Stairs

28. Descending Ramp

29. Distance Detected Level Ground vs. Descending Ramps Ramp

30. Next Steps Figure out how it is going to attach to the brace Find Ramp Gait Data Test out IR sensor Define algorithm for determining floor surface Model Design

31. Questions?