CUSTOMIZED PATIENT SOLUTION SD17-005 Faculty Advisor: Dr. Gabbard Company Contact: Jacky Hostetter
Abby Armstrong
Somer Hand
Niki Khandelwal
Sam Meaux
COMPANY DESCRIPTION
Personal Care + Homemaker Agency
Lexington, VA
Devin Robinson
Jacky Hostetter
ME + ISE Teams with Devin, Jacky, + Sherri
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PROBLEM STATEMENT
• Design + build a desk, footrest, + keyboard for a patient with Muscular Dystrophy (MD) • These assistive technologies will help mobilize Devin
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SCOPE
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01: Industrial Engineers • Ergonomic analysis • Human interface design • System interface design
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02: Mechanical Engineers • Structural analysis
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• CAD models • Power transduction
03: Joint Effort • Keyboard • Desk • Foot rest
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OBJECTIVES
Increase Productivity
Reduce Healthcare Costs
Improve Quality of Life
TARGET SPECIFICATIONS
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Desk
Footrest
Keyboard
• 3 axes of adjustability • 15 sec disassembly time
• Noticeable reduction of pain and swelling in feet/ankles • Increase in range of motion
• 150% increase in characters/minute
DESIGN METHODOLOGY
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Engineering Design Process
Recognition of Challenge
Information Gathering
Idea Evaluation
Problem Definition
Build
Idea Generation
Validation
SOLUTION
DESK Customer Needs: • Desk needs to fit through doorway + fit laptop + keyboard • Sturdy • Adjustable desk position
Target Specifications: • Size of desk surface top: 24” x 22” x 1” • Weight: 9 kg (20 lbs) • Maximum stress: 30 ksi
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SOLUTION
DESK - 3D MODEL
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SOLUTION
DESK ATTACHMENT TO WHEELCHAIR
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SOLUTION
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FOOTREST Customer Needs: • Size • Angular adjustability • Sturdiness
Target Specifications: • Height, length, width • Angle of adjustment • Maximum stress Image from Seating Dynamics
SOLUTION
FOOTREST PADDING • Inspired by prototyping session • Comfort Company • Padding thickness 1.75” • Wooden board screwed onto footplate
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SOLUTION
TIGHTENING OF FOOTREST PADDING Side Release Buckle Straps: • Polyester • Prevent foot from sliding forward and tightens width of footbox padding Image from Amazon
Fleece Noseband Cover: • Cover strap to prevent irritation/rubbing on ankles
Image from Dover Saddlery
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SOLUTION
FOOTREST ATTACHMENT
T-slot on Wheelchair
Footrest Insert and Attachment
Before: No Footrest
After: Footrest Attached
SOLUTION
KEYBOARD
Customer Needs: • Increased typing efficiency • Less arm movement to reach keys
Target Specifications: • Shorter distance from keys to hand • Cursor navigation integrated into keyboard
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SOLUTION
LEFT HAND COMPONENT
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SOLUTION
RIGHT HAND COMPONENT
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SOLUTION
CUSTOM KEY LAYOUT
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IMPACT Desk • 3 axes of adjustability • Assembly: 13.5 seconds, Disassembly: 10.5 seconds
Footrest • Reduction in swelling: LS - Ankle: 11 → 10 in, Arch: 11.75 → 11 in, Ball: 10.25 → 10 in RS - Ankle: 11.25 → 10.5 in, Arch: 10.75 → 10.5 in, Ball: 10.25 → 10 in • Increase in ROM, Reduced pain
Keyboard ● Old keyboard: 27.9 seconds, New keyboard: 21.8 seconds
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IMPACT CONTINUED
Client’s Final Remarks: “The swelling in my feet is going down. They’re at least half the size. I might even be wearing shoes again by graduation time.” (April 10th) “I’ve spent my whole life adapting to things in the world, so it’s been really great having things adapted to me for a change.”
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SPECIAL THANKS
• Professor Ott • Jacky Hostetter • Greg Peek • Sean Rahall • ME Team Members
CUSTOMIZED PATIENT SOLUTION SD17-005 Faculty Advisor: Dr. Gabbard Company Contact: Jacky Hostetter
Abby Armstrong
Somer Hand
Niki Khandelwal
Sam Meaux
IMPLEMENTATION PLAN
Manufacture + Build
Testing
Prototyping
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Design Refinement
Design Verification
STRESS ANALYSIS
● U-bolt clamp was replaced with a vibration damping u-bolt ○ Previous U-bolt clamp: Max stress = 11.59 ksi ○ New U-bolt: Max stress = 11.38 ksi
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SAFETY FACTOR
● Previous U-bolt clamp: min SF = 3.44 ● New U-bolt: min SF = 2.89
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WHEELCHAIR ATTACHMENT
● Coupling Nuts ○ ¼” diameter ○ Distance from centers = ⅜” ○ Replacing old block ● Socket Caps ○ ¼”-20 x 1½" Socket-Cap Anchor Bolt ○ Tighten/Loosen with Allen Wrench ○ Replacing old socket caps ● Circular Tube ○ Diameter = ¾” ○ Length = 3”
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ANGULAR ADJUSTMENT
Footplate Angular Adjustment - Allen Wrench Size: - Top Screw - 3/16” - Side Screw - 5/32”
Knee Angular Adjustment - Allen Wrench Size - Side Screw - 5/32
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48 Tooth Spline Feature - 7.5° Increments - 360° Range of Motion
HEIGHT ADJUSTMENT
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Conical Wedge
Divet to allow expansion How it Works - 6” of Height Adjustability - Allen Wrench Size - 7/32” - Tighten bottom bolt to pull down conical wedge - Conical Wedge puts pressure on inner tube to hold height in place
FOOT BOX
● Inspired by prototyping session ● Style: Standard ● Dimensions: 7” W x 10” L x 8” H ● Padding Thickness 1.75”
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RESISTANCE BAND & PADDING
Resistance Band by RAGE ● Dimensions: 18” L x 13/16’ W (2 Bands per Foot Box) ● Material: Rubber ● Purpose: Prevent foot from sliding forward due to angle of footplate and tighten the width of padding
Fleece Hackamore Noseband Cover ● Dimensions: 9” L ● Material: Fleece ● Purpose: Cover rubber padding in the front of the footbox to prevent discomfort
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CURSOR NAVIGATION
5 Pin PS2 style Joystick ● moves cursor around screen
Logitech Trackman Marble Trackball ● no software or alteration electronically ● retained L and R click functions
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JOYSTICK OPERATION
Flow Chart for joystick as cursor navigation
Arduino Leonardo: microcontroller
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JOYSTICK CODE
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ELECTRICAL SCHEMATIC
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ELECTRICAL SCHEMATIC
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SOFTWARE
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Keyboard
Joystick
gh60: Edited in Visual and Compiled
Arduino IDE
in Ubuntu Bash