A Clean Hand Device for Manual Wheelchairs

March 4, 2004

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Team Members

• Fannie Black

• Peter Pipchenko

• Jeff Dahlgren

• Mitsunori Kaibara

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Presentation Scope• To review the history of the project and

our four step process work.

• To summarize what we have done and plan to do in the areas of:– Design– Analysis– Verification

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Original Proposal Change

• Sponsor requested us design of a complete “clean hand” wheelchair.

• After consideration of the market niche, we successfully pitched designing an add-on alternative propulsion clean hand device.

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Mission Statement• We will design an alternative propulsion

“clean hand” device for manual wheelchairs that will be inexpensive and fit the most popular wheelchairs in use today.

(Rev. 1)

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PDS Criteria Selection• Biomechanical Efficiency

• Fits Popular Chairs

• Adjustability & Comfort

• Controllability – Braking, Turning

• Environmental Survivability

• Impact Strength

• Size & Weight

• Device Attachment Point

• Customer Installation

• Safety

• Company Cost

• Appearance

(Rev. 2)

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External Search - 1

Gloves Wijit

Handcycle

Motorized

Competing SolutionsComparison

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External Search - 2Analysis Methods

Wheelchair User Statistics Alternative Propulsion Test

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Internal Search - 1

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Internal Search - 2

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1st Critical Step

• We realized designing this device required personal experience with a wheelchair.

• We rented a wheelchair and rode it around.

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Wheelchair Use Learnings

• Your hand really does get filthy!

• Controllability is the highest priority.

• Side space is incredibly limited.

• Adaptability will be key.

• We don’t really have a clue what it’s like, so we must get wheelchair user input.

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Final Concept Selection

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Hybrid Concept

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2nd Critical Step

• We had two meetings with actual wheelchair users.

• We wanted to get their input on our design criteria.

• We wanted to see if they would buy and use our final concepts.

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Wheelchair User Learnings

• They substantially shot down all ideas, because of four main factors:– The motion was too complicated and required too much

relearning.

– The devices stood out too much. Disabled people want to minimize their disabilities.

– No propulsion method gives better control to actual manual wheelchair users than the traditional hand to rim method.

– All they and the sponsor really want is a clean hand guard, without the alternative propulsion aspect.

• Back to the drawing board.

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Human Element• There’s a strong human element in this project.

We’re designing a device that will literally become a part of a person’s body.

• There’s nothing more personal than that, and thus the most important factor in designing this device has to be how the user feels. We had completely ignored this before.

• The user must be consulted as early as possible in the design of any product with a strong human element.

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Revised Mission Statement

• We will design an alternative propulsion “clean hand” device for manual wheelchairs that will be inexpensive and fit the most popular wheelchairs in use today.

(Rev. 2)

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Revised PDS Criteria• Biomechanical Efficiency

• Fits Popular Chairs

• Adjustability & Comfort

• Controllability – Braking, Turning

• Environmental Survivability

• Impact Strength

• Size & Weight

• Device Attachment Point

• Customer Installation

• Safety

• Company Cost

• Appearance

(Rev. 3)

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Revised ConceptCounterbalanced Squeezable Hand Rim Extender & Guard

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Without the lever arm

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Revised Concept

• Wheel Spider Attachment Point

• Adjustable Default Counterbalance Position

• Palm Guard

• Rim Extender

• Squeezable Grip

(Cont’d)

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What We’ve Done• Design

– Concept Brainstorming– 9 Different Concept Models

– A Complete Wheelchair Model from Actual Dimensions

• Analysis– Zero

• Verification– Rode a Wheelchair to Consider Our Concepts– Got Input from Wheelchair Users about Our Designs

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What We Plan To Do• Design

– Material Selection & Part Sourcing– Nuts & Bolts Model (Add Fasteners, Bearings)– Dimension Drawing (Piece Part, Assy)– Plastic Part Mold Model & Drawings (Parting Line, Draft Angles)– Final Concept Refinement

• Analysis– Strengths Analysis of All Components– Machine Design Fatigue Analysis of Bearings, etc.

• Verification– Simple Cardboard Prototypes– Tougher Metal or Wood Prototypes for Actual Use– Testing of Prototypes by Wheelchair Users

Please ask questions.Thank you.