2.  Team Members: ◦ Pattie Schiotis – Team Manager (ME) ◦ Shane Reardon – Lead Engineer (ME) ◦ Dana Kjolner (EE) ◦ Robert Ellsworth (EE) ◦ Sam Hosig (CE) ◦ John Williams (CE) Faculty Guide: Dr. Elizabeth DeBartolo

3.  Introduction  Project Background  Key Customer Needs  System Architecture  Component Breakdown ◦ Mechanical Locking System ◦ Electronics Circuit and PCB ◦ Sensors ◦ Microcontroller  Testing Results  Future Work  Demo

4.  Inability to dorsiflex the foot due to loss of control of peroneal nerve  Lasting side effect of a stroke, affecting approximately 20% of stroke survivors ◦ ~20 million people per year  Condition can also occur as a side effect of ALS (Lou Gherig's Disease), Multiple Sclerosis, or injury to the peroneal nerve, increasing the number of people affected  People with this condition have difficulty maintaining a proper gait cycle ◦ “Foot crash”

5.  Patients have adopted the use of ankle foot orthotics (AFOs) to aid with dorsi flexion  Market consists mostly of “passive” devices ◦ Rigid braces which prevent unwanted plantar flexion. Foot is always pointed in the upwards direction.  These devices do not allow for safe maneuvering down stairs and ramps  The goal of this project is to design and develop an “active” AFO which allows safe movement on flat surfaces as well as up and down stairs and ramps

6.  User will have no ability to either plantar-flex or dorsi-flex their foot  Side to side stability of the foot will be ignored  Worst case will be analyzed: ◦ 95 percentile male having heavy foot. ◦ Fast walker – gait cycle less than 1 second.  Device may not use air muscles as an actuation source  AFO Custom made for each client

7. Primary Needs:Secondary Needs:  Safety  Portable ◦ Lasts all day without charging/refueling ◦ Lightweight ◦ Tolerable to wear all day  Reliable  Accommodates Flat Terrain  Accommodates Special Terrain ◦ Stairs ◦ Ramps ◦ Obstacles  Comfortable ◦ Aesthetically Pleasing  Durable ◦ Water Resistant ◦ Corrosion Resistant  Salt & Environment  Biocompatibility  Convenient ◦ Easy to put on and take off

8. Spec Number Engineering Specification Description Units of Measure Nominal Value s1Torque on Footft-lbf±2 s2 System response time (sensing terrain to actuating device) ms<400 s4predicts step downyes/noyes s5predict flatyes/noyes s7predicts ramp downyes/noyes s10 allowable range of motion between foot and shin degrees70 to 135 s12untethered usage timehrs/steps 10 hrs/ 3000 steps s17force to secure constraintslbf< 18 s18force to remove constraintslbf< 18 s23radius of edges/corners on AFOin<0.02 s24weight of entire devicelbf≤2.2 s28 Operates in environment temperature range °F0-100

9.  CAD model Sensors Piston/Cylinder Mounting Bracket Valve Battery Processor Reservoir

10. Concept:Selectively prevent foot from plantar flexing while off the ground  Piston-cylinder arrangement attached posterior to heal and calf via 2 pin joints  Piston actuates within cylinder as dorsi & plantar flexion occurs

11. “Locked” Mode“Free” Mode  Valve on top of the cylinder is closed  Water inside cylinder is compressed by piston upon plantar-flexion  Motion of piston is therefore restricted, preventing plantar flexion  Valve is open  Water is free to travel between cylinder and reservoir upon actuation of piston  Allows for plantar and dorsi flexion

12. LED SD Card Switch Connector

13.  Utilize sensor system developed by MS student Christopher Sullivan  Vertical sensor determines if the foot is on or off ground  Forward sensors detects upcoming terrain

14.  Processing path of microcontroller

15.  Range of Motion ◦ 70.03º-147.27º  Weight of Device ◦ 2.42 lbs  Terrain prediction ◦ Detects flat, descending stairs and ramps  System Response Time ◦ Average ~300ms

16.  Create smaller electronics box ◦ Reduce weight, improve aesthetics, switch in correct location  Different battery ◦ Reduce size and weight, improve usage time  Recommend using plastic fittings ◦ Weight reduction, corrosion resistance, could not find in store  SD card expansion board ◦ Improve data collection  Human Trials with AFO that fits user ◦ More accurate data collection

17.  Budget breakdown…

18. Demonstration