Ankle Linear Force Comparison A (reference)BCD Current Passive-Dorsi-flex AFO Dorsi-flex assist AFOPlantar-flex assist AFOPlantar/Dorsi assist AFO Segment Selection CriteriaWeight Required Force (N) Wtd Required Force (N) Wtd Required Force (N) Wtd Required Force (N) Wtd Required Plantar Flexion Force 50% Required Dorsi Flexion Force 50% Total Force

Risk Assessment IDRisk ItemEffectCause Likelihood Severity Importance Action to Minimize RiskOwner Describe the risk briefly What is the effect on any or all of the project deliverables if the cause actually happens? What are the possible cause(s) of this risk? L*S What action(s) will you take (and by when) to prevent, reduce the impact of, or transfer the risk of this occurring? Who is responsible for following through on mitigation? 1 Failure of the device while the air muscles are activated The patient will not be able to release from plantar-flexion Solenoid failure; air source failure 224 Developed a backup system within the solenoid bank. Many risks cannot be accounted for in the design of the system Bob Day 2 Stretching of the tendon wire The air muscles will not control the joint movement as well Poor material selection/inability to re-tension tendon cables326 Implement a cable tensioning device (ie: bicycle cable tensioner) to allow for adjustable tensionPat Renahan 3 Generating tone-lock spasms Inability to move your foot out of the position in which the nerve fiber locks the muscle Rapid movement of the foot212 Keep the air muscle activation at a slow enough rate to reduce this risk. Full control over this risk is impossible as it is a patient-specific, neurological malfunctionBob Day 4 Pressure source attachment points Air muscle detachment from commercial AFO Poor material selection/stress- strain analysis236 Over-engineer the air muscle attachment point design Patrick Streeter 5 All attachment points on the AFO that could result in an irritation or pressure sore Pressure sores or irritations found on patients using device Rough attachment points to AFO212 Smooth padding located on the inside of the commercial AFO, small muscle to AFO attachment points Patrick Streeter 6 Popping the pressure-fed air muscles when too much or too little counteracting force is applied Loss of air muscle power, and would result in the need to replace air muscles Inadequate dynamic analysis or pressure- failure system development236 Develop a program that coordinates the firing of the pneumatic system with the gait cycle of the patientBob Day

7 Inadequate material durability Failure of selected materials in differing environments Poor material selection/analysis224 Over-engineer the materials used in the AFO device and attachmentsNate Couper 8 Completion of work within scheduled times Ladder-effect of other work getting pushed behind, or work- overload at the end of the quarter Poor project planning and management212 Continually update project schedule, and meet bi-weekly at minimumPat Renahan 9 Unbalanced distribution of work load Different team members carrying the majority of the workload at different points during the design process Poor distribution of workload and poor project management212 Discuss workload and time commitments from the previous week at bi-weekly meetings 10 Completing the project within the specified budget Inability to continue to fund the project through completion Poor project management and inadequate budget calculations111 Develop an in-depth budget, and continually update it as progress continues to be madePat Renahan 12 Over simplifying the analytical model Inadequate supply of power or inadequate material selection due to assuming certain forces negligible Desire to reduce needed calculations and oversimplifying to make calculations easier122 Work in sub-teams of two or greater to allow for a checks and balances system for calculations 13 Keeping the noise level of the air muscle system below 60 dB Uncomfortable surroundings in the clinical setting Inadequate muffling of the pneumatics system212 Implement a muffler system for the pneumatics that reduces the noise as much as possible maintaining minimal size and mass, and avoiding negative effects on the pneumatics systemBob Day Likelihood scaleSeverity scale 1 - This cause is unlikely to happen 1 - The impact on the project is very minor. We will still meet deliverables on time and within budget, but it will cause extra work 2 - This cause could conceivably happen 2 - The impact on the project is noticeable. We will deliver reduced functionality, go over budget, or fail to meet some of our Engineering Specifications. 3 - This cause is very likely to happen3 - The impact on the project is severe. We will not be able to deliver, or what we deliver will not meet the customer's needs.

Plan B Actions (for those with importance rating of 4 or higher) Failure of the device while air muscles are activated – Allow for the air system to be easily disconnected (quick connects) – Allow for the air system to be easily shut-off in case of an unexpected design failure Pressure source attachment point failure – Allow for the air muscles to be quickly connected to the AFO by a commonly used material (zip ties) – Supply the clinic/setting with spare muscle assemblies Popping the pressure-fed air muscles when too little or too much force is applied – Supply the clinic/setting using this device with spare air muscle assemblies Inadequate material durability – Supply the clinic/setting using this device with spare air muscle assemblies NOTE: Due to the clinical setting of our patients, these actions are not of much concern as the patient is in a safe environment where the device can be easily manipulated and fixed

Project Schedule Upcoming priority deadlines: – Fall Quarter Week 9: Detailed Design Review Reference EDGE website for working, detailed project schedule: Planning and Execution – Project Plans and Schedules – “Schedule of Action Items”