Status Report 3 Senior Design, BME 273 Professor: Dr. Paul King March 27, 2000 Members: Wan-Yin Chan, Megan Lan, T.J. Payne Advisor: Dr. R. Steven Couch, M.D. Advisor: Dr. R. Steven Couch, M.D. (Assistant Medical Director for Pediatrics at Vanderbilt Stallworth Rehabilitation Hospital)

Project Description: Hand-Operated Riding Lawnmower n Problem: Subject with spinal cord injury is unable to safely operate Riding Lawnmower due to lack of lower body control n Objectives: Modify a riding lawnmower to address the physical limitations of a paraplegic and to further enhance safety

Paraplegic Patient Information n Name: Mark Singer n Age: 27 n Weight: 165 lbs n Height: 5’8” n Shoe Size: 10.5 n Education Level: Associates Degree in Mechanical Engineering n Level T8 Spinal Injury n Wheelchair Model: Action Terminator with 25 in. wheels

Project Modules n Safety Analysis and Brainstorming: ALL n Brake Conversion: T.J. Payne n Mount/Dismount System: Megan Lan n Foot/Body Restraints: Wan-Yin Chan n Additional Modifications

Brake Conversion System n Considerations –Standard foot-powered push pedal attached to pull cable n activates brake and clutch for shifting gears –A 2.5-inch pull of the cable is required to stop the mower n Possible Ideas –Bicycle-style handbrake attached to pre-existing cable –Push-lever system similar to that employed in subject’s car –Single fulcrum pull-lever system

Brake Modifications n Chose pull lever –Longer pull than handbrake –Mechanical advantage n 1/3:2/3 total length ratio or 12”:24” cable-fulcrum: fulcrum-handle distance –Fewer moving parts than push lever n less mechanical failure n Components –One 36” steel pipe –One 1/4” x 2” hex bolt with two 3/16” hex nuts and lock washers

Brake Modifications

Mount/Dismount System n Previous Ideas - Swing-away handle bar, Overhead bar n Final Idea - Ramp n Ramp Dimensions: –Height: 7 inches --> –Slope length: 7 feet –Slope width: 48 inches –Platform: 60 x 60 inches (wheelchair length = 28 inches)

Completed Ramp Completed Ramp

Foot Restraint System n Foot statistics –Shoe length: 13 inches –Shoe width: 4.5 inches (widest) n Velcro Restraint System –1 inch wide velcro –5.5 inch foot gap n Purpose: Stabilization of Legs and Feet

Schematic of Foot Restraint System

Body Restraint System n Seat Belt –Visual Aids –Placement –Purpose

Current Status n Mount/Dismount, Foot Restraint, and Brake Conversion Systems have been completed n Designsafe Analysis has been completed n Project Costs - approximately $115 –Tax-free ramp materials, free delivery –Used seat belt –Free velcro

Needs/Future Work n Finish Body Restraint System n Touch up on New Hand Brake n Test on paraplegic subject n Create Poster Presentation n Write Final Paper

Special Thanks n Mark Singer n Kenton Dickerson n Dr. Steven Couch n Dr. Paul King n Karen Fuller

Contacts and Relevant Information n Advisor - Dr. Couch, M.D. –Vanderbilt Stallworth Rehabilitation Hospital, MS Clinic –(615) n Subject - Mark Singer –Easter Seals Tennessee –(615) , ext. 104 n Our website: