Transcript KAir-FOrce: A Fully Adjustable Knee-Ankle

K-Air FOrce
Doug Follmer
Shubhra Kochar
Lauren Levey
Adam Zurmehly
Outline
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Clinical evaluation
Initial design process
Design procedure
Device evaluation and testing
Device demonstration
Future recommendations
Acknowledgements
Spinal Cord Injuries
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Affect neuromuscular and sensory function below
level of injury
~12,000 new injuries per year
Shorter life expectancy, higher cost of living
Rehabilitation
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4-6 months of outpatient therapy
Maintaining and building muscle strength
Knee-Ankle-Foot Orthotics
 T-6
injuries and below
 Home mobility
 Highly Customized
 Acceptance Rate
 2008
Article: 58-79% abandoned
 40% of remaining users express dissatisfaction
http://www.cascadeusa.com/products/ORTHOTICS/LOWER%20EXTREMITY%20ORTHOTICS/FRACTURE%20BRACES/MARAME
D%20TIBIA%20FRACTURE%20BRACE%20S-SERIES.aspx
Project Definition
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Adjustable KAFO for clinical diagnosis
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Design Requirements
 Leg
size and height adjustments
 Ankle Support
 Ability for knee flexion
 Comfort
 Fatigue Resistance
Image: Picture of KAFO padding
Design Idea Process
Initial Design
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Thigh: three piece design
Shank: two piece design
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Foot plate
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straps
Thermoplastics
thermoplastics
Hard plastic
Initial Design
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Telescoping- steel and Titanium rods
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Knee and Ankle joints- Ultraflex
Design Process
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Re-evaluation of components in terms of strength,
stability, machinability, adjustability and weight.
More research
Limitations in available components
New ideas
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Carbon fibers
Revisited the previous ideas
Improvisation of initial design
Final Design
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Thigh and shank:
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One piece design with air pockets and padding
Final Design
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Knee and Ankle joints
Solid Stirrup
Knee-joint
Orthoamerica
Ankle-joint
OTS Corp
Carbon fiber foot
Final Design
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Telescoping:
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Continuous mechanism
Adjustment between knee and thigh and shank and ankle
Design Procedure
Thermoplastic
Plaster Bandages
Plaster of Paris Mold
EWI Oven (~ 195˚ C)
Positive Mold
of the Thigh
Thermoplastic (~
9 min)
Carbon Fiber
Carbon Fiber
Mold Release
Epoxy Resin
Hardener
Carbon Fiber Feet:
Left - First Attempt
Right - Second
Attempt
Assembly
Metal Rods/Telescoping
Aluminum Rod: Top
View
Machined Bracket for Telescoping
Aluminum Rod:
Side View
Air Pocket Fabrication
Air Cast
EWI: OSU Welding Engineering Division Plastic Welding
Assembly
Padding / Velcro
Final KAFO - Side View
Ankle Joint
Velcro
Final KAFO - Front View
Device Evaluation and Testing
Review of Requirements
What’s Important
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Knee Joint
Ankle Joint
Height/Diameter
Adjustment
Padding
Straps
Key Areas
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Support
Stability
Adjustability
Comfort
Weight
Cost
• Patient #1: Ben
• Height: 6’1”
• Injury: L1
incomplete
Evaluation
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Patient #2: Perry
Height: 5’9”
Injury: T10-T11 Complete
Demonstration
Thermoplastic
Padding
Aircells
Orthomerica
Knee Joint
Carbon Fiber
Foot
OTS Orthotics
Ankle Joint
Future Recommendations
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Non-riveted Velcro strap
Knee Joint alterations
 Lock
in extension
 More strength in bolts
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Shank adjustment
Carbon Fiber Foot
Screws Protruding
Tools
Orthotist
Acknowledgements
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Dr. David Lee- Machine Shop, Mentor
Dr. Mark Ruegsegger- Mentor
Heather Loge- D.Physical Therapist, Clinician Mentor
Melissa Aston- Physical Therapist, Testing advisor
Rowan, Ben, and Perry- Patients, Test Subjects
North Sea Plastics- Thermoplastic Donation
OrthoMerica- Knee Joint Donation
Kirk Cooper, EWI- Thermoplastic forming
Dr. Avraham Benatar, OSU: MSE- Plastic Air Pocket Welding
Ryan- Scott Labs Machine Shop
Rowan, Ben, and Perry- Patients, test subjects
Jerry, Hanger Orthopaedics- Ankle Stirrup bending
Bruce Chase- Carbon Fiber advice
Rob Kapaku- Team Name Punnery
QUESTIONS?
Resources
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Otto, Judith Phillipps. “The Stance Control Orthosis:
Has Its Time Come?” The O&P Edge. Online article