System Design Review P15007: Anti-Rollback Wheelchair Jessica Jeffrey – Industrial Engineer / Project Manager Jacob McCarthy – Mechanical Engineer Warren Roser – Mechanical Engineer John Sweet – Mechanical Engineer

Agenda Background (~2 min) Action Items and Resolutions (~3 min) System Architecture (~1 min) Functional Decomposition (~6 min) Morphological Analysis (~2 min) Pugh Chart (~10 min) Concept Selection (~2 min) Benchmarking (~10 min) Scope (~3 min) Risk Assessment (~5 min) Feasibility (~6 min) Test Plan (~1 min) Project Plan (~2 min) P15007 Anti-Rollback Wheelchair 9/30/2014

Background Users of manual wheelchairs encounter issues when  traversing up an incline or down a decline P15007 Anti-Rollback Wheelchair 9/30/2014

Action Items and Resolutions Updated Engineering Requirements Updated Use Scenario Repair Alpha Prototype Monroe Wheelchair Visit Benchmarking Alpha Prototype P15007 Anti-Rollback Wheelchair 9/30/2014

Updated Engineering Requirements * Functions Key 9 High 3 Moderate 1 Low P15007 Anti-Rollback Wheelchair 9/30/2014

Updated Use Scenario Aid and Client Interaction Aid Assists Client into Chair Client Propels Themselves on Flat Terrain Aid Available for Steep Inclines/Declines Aid Instructs Client to Engage/Disengage Hill Holding System Client Continues Self Propulsion on Flat Terrain P15007 Anti-Rollback Wheelchair 9/30/2014

Ratchet and Pawl System System Architecture Client / Aid Input Ratchet and Pawl System Disc Braking System Manual Wheelchair Engagement P15007 Anti-Rollback Wheelchair 9/30/2014

Functional Decomposition (1 of 3) Main Function: Control Motion P15007 Anti-Rollback Wheelchair 9/30/2014

Functional Decomposition (2 of 3) Stop Backwards Motion Ratchet and Pawl System P15007 Anti-Rollback Wheelchair 9/30/2014

Functional Decomposition (3 of 3) Impede Forward Motion Braking System P15007 Anti-Rollback Wheelchair 9/30/2014

Morphological Analysis P15007 Anti-Rollback Wheelchair 9/30/2014

Selection Criteria Material Cost Ease to Transport Labor Cost Ability to Complete in 2 Semesters Additional System Weight Reliability Additional Width Safety COTS Components Ability to steer down decline Ability to prevent rollback Ergonomic Adjustability Ability to slow on decline Maintenance Ability to stop on decline System Adaptability Ease of Collapsibility Ease of Installation P15007 Anti-Rollback Wheelchair 9/30/2014

Pugh Chart (1 of 2) DATUM: Manual Wheelchair Key + Improved Equal - Diminished Pugh Chart (1 of 2) DATUM: Manual Wheelchair P15007 Anti-Rollback Wheelchair 9/30/2014

Pugh Chart (2 of 2) DATUM: Alpha Prototype Key + Improved Equal - Diminished Pugh Chart (2 of 2) DATUM: Alpha Prototype P15007 Anti-Rollback Wheelchair 9/30/2014

Concept Selection Beta Concepts 1 & 2 Multiple Pawls Mechanical Disc Brakes User Controls P15007 Anti-Rollback Wheelchair 9/30/2014

Benchmarking: Alpha Prototype Team Member Ergonomics System Safety Jessica 1 3 Jacob Warren John Key 9 Excellent 3 Good 1 Poor P15007 Anti-Rollback Wheelchair 9/30/2014

Benchmarking: Monroe Wheelchair Visit Jonathan Walters, Vice President Custom VS Standard Options Rigid Frame VS Collapsible Frame Spoked Wheel VS Spokeless Wheel P15007 Anti-Rollback Wheelchair 9/30/2014

Benchmarking: Major Brands P15007 Anti-Rollback Wheelchair 9/30/2014

Benchmarking: Major Brands P15007 Anti-Rollback Wheelchair 9/30/2014

Benchmarking: Competitive Solutions Parameters/ Products Grade Aid Magic Wheels The Pivot e-motion D's Locks ADI Disc Brake Cost $180 ~$5000 ~$4770 $7,675.00 + $500+ $750+ (some over $1,150) Weight ~3 lbs ~10 lbs (additional) ~ 12 lbs (additional) 10 lbs (additional) + 2 lbs Not Available Function Anti-rollback for incline Hill holding and gear reduction Dual levers, Parking brake, anti-rollback hill holder Slows Rollback and assists motion Locks wheels to prevent chair from moving when transferring in / out of chair. Manual Braking System Interfacing Replaces factory wheel locks Replaces stock wheels Replacing quick-release rear wheels Attaches to wheel and stock axle Attaches to quick detach wheels on custom chairs Limitations Works best with inflatable tires Price Mostly Replaces current wheels entirely Maximum Range of 16 miles, increases width by 1-1.5" Only used when stationary Needs to be a quick detach wheel Maintenance Sealed gearbox, factory serviced only Battery Recharge & Replacement none Occasional to replace pads or rotor Universality Fits most Quickie wheelchairs Fits most manual wheelchairs with supplied adapter(s), customers are asked to call for verification Tube diameters 22.2mm, 25.4mm, 28.6mm, 30mm, and 31.8mm (7/8", 1", 1 1/8", 1.2", and 1 1/4"). Only Compatible with manufacturer specified wheelchairs. Compatible With specified chairs, approx 50 models. Compatible with a various custom chairs

Benchmarking: Grade Aid P15007 Anti-Rollback Wheelchair 9/30/2014

Benchmarking: D’s Locks P15007 Anti-Rollback Wheelchair 9/30/2014

Benchmarking: ADI Disc Brake P15007 Anti-Rollback Wheelchair 9/30/2014

Scope: Retrofittable Possible Target Wheelchairs Standard (Not Custom) Collapsible Frame (Not Rigid) Standard Wheels (Not Quick-Release) P15007 Anti-Rollback Wheelchair 9/30/2014

Scope: Users Target Users: Men and Women Age 65+ Any Wheelchair   Any Wheelchair Manual wheelchair Electric wheelchair Number (1000s) % of population Total 1,599 0.61 1,503 0.58 155 0.06 Age Under 18 88 0.12 79 0.11 18 0.02 18-64 614 0.39 560 0.35 90 65+ 897 2.87 864 2.76 47 0.15 Gender Male 658 0.52 606 0.48 84 0.07 Female 941 0.7 0.67 71 0.05 http://www.cdc.gov/nchs/nhis/nhis_disability.htm P15007 Anti-Rollback Wheelchair 9/30/2014

Risk Assessment (1 of 2) P15007 Anti-Rollback Wheelchair 9/30/2014

Risk Assessment (2 of 2) P15007 Anti-Rollback Wheelchair 9/30/2014

How long does our device have to last? Feasibility (1 of 3) How long does our device have to last? Average wheelchair lifespan, 5-15 years Insurance company funds replacement every 5 years Average wheelchair uses travels 1.6km per day Assume 24” wheel 1524678 revs in 5 years 4574034 revs in 15 years P15007 Anti-Rollback Wheelchair 9/30/2014

What loads does our device have to support? Feasibility (2 of 3) What loads does our device have to support? Assumed 300 lb load limit Load applied directly at wheelchair center P15007 Anti-Rollback Wheelchair 9/30/2014

Feasibility (3 of 3) What is the resolution of the ratchet and pawl and how can we improve it? 24 Inch Wheel Teethê\Pawls è 1 2 3 40 1.88 0.94 0.63 60 1.26 0.42 80 0.47 0.31 22 Inch Wheel Teethê\Pawls è 1 2 3 40 1.73 0.86 0.58 60 1.15 0.38 80 0.43 0.29 26 Inch Wheel Teethê\Pawls è 1 2 3 40 2.04 1.02 0.68 60 1.36 0.45 80 0.51 0.34 P15007 Anti-Rollback Wheelchair 9/30/2014

Engineering Requirement Test Plan Test Engineering Requirement Test ergonomics of controls Component life tests through theoretical analysis Designed test life Test force input to brake down an incline using force gauge. Use wheelchair ramp on campus that is standard 1:12 slope to conduct test. Grip force exerted by user to brake on decline Measure wheelchair width with and without system installed, and compare. Do this for the wheelchair in the folded state and in use state. Increase of wheelchair width when in use; Component interference when wheelchair is folded Test hold on incline with maximum rated load for standard wheelchair. Force exerted by user to hold position on incline Measure total additional weight from installation of the system Total system weight Measure time it takes to detach the system and revert to original wheelchair configuration Time to revert to original configuration P15007 Anti-Rollback Wheelchair 9/30/2014

Project Goals: Phase III Further Evaluate Feasibility of Concept 1 & 2 Cost Analysis Maintainability Functionality Choose Final Ratchet and Pawl Design Develop Prototype P15007 Anti-Rollback Wheelchair 9/30/2014

Phase III Benchmark Opportunities Dr. Day: CP Rochester Southside Medical Supply Westside Medical Supply Access Lifts & Ramps P15007 Anti-Rollback Wheelchair 9/30/2014

Thank You! P15007 Anti-Rollback Wheelchair 9/30/2014