1. Four-Bar Mechanism to Drive a Wheelchair Gordon Farmer Submitted to the 2007 ASME Student Mechanism Design Competition Undergraduate Category University of Notre Dame du Lac Dr. M.M. Stanišić September 5, 2007

2. Erdman, Arthur G., and Sandor N. George. Mechanism Design: Analysis and Synthesis. Vol. 1. Englewood Cliffs, New Jersey 07632: Prentice-Hall, Inc., 1991. Introduction Design Problem Shortcomings of Traditional Driving Method Design Objectives Four-Bar Overview Kinematic Solution Curvature Theory Design Optimization Final Design

3. Introduction Design Problem Shortcomings of Traditional Driving Method Design Objectives Four-Bar Overview Kinematic Solution Curvature Theory Design Optimization Final Design Direct contact with wheels Poor braking Health issues “More than 50% of […] respondents with spinal cord injury in a study […] reported shoulder pain that was related to wheelchair use and transfers.” 1 “Shoulder related injuries have been shown to be present in up to 51% of manual wheelchair users.” 2 “The prevalence of elbow, wrist, and hand pain has been reported to be 16%, 13%, and 11%, respectively.” 2 “The incidence of carpal tunnel syndrome and rotator cuff tendonitis […] is greater than 50% for people who regularly use manual wheelchairs as compared to 3% for the general population.” 2 1 Koontz, PhD, ATP, Alicia M., and Michael L. Boninger, MD. "Proper Propulsion." Rehab Management July 2003. 29 June 2007. 2 Manual Wheelchair Propulsion. Rehabilitation Engineering Research Center on Technology Transfer. Mid-Atlantic Region: Federal Laboratory Consortium.

4. Introduction Design Problem Shortcomings of Traditional Driving Method Design Objectives Four-Bar Overview Kinematic Solution Curvature Theory Design Optimization Final Design 1)Desired path of handlebar: 4 y = x 2 2)High mechanical advantage M a = T Load /F Driver 3) Remain within wheelchair profile

5. Introduction Design Problem Shortcomings of Traditional Driving Method Design Objectives Four-Bar Overview Kinematic Solution Curvature Theory Design Optimization Final Design

6. Introduction Design Problem Shortcomings of Traditional Driving Method Design Objectives Four-Bar Overview Kinematic Solution Curvature Theory Design Optimization Final Design

7. Introduction Design Problem Shortcomings of Traditional Driving Method Design Objectives Four-Bar Overview Kinematic Solution Curvature Theory Design Optimization Final Design

8. Introduction Design Problem Shortcomings of Traditional Driving Method Design Objectives Four-Bar Overview Kinematic Solution Curvature Theory Design Optimization Final Design 1)High, positive mechanical advantage 2)High mechanical advantage when handle is pulled back 3)Mechanical advantage decreases in a relatively linear fashion as the handle moves forward 4)Span of four-bar mechanism is reasonable, given an individual’s normal reach. Between 0” and 20” on y-axis.

9. Introduction Design Problem Shortcomings of Traditional Driving Method Design Objectives Four-Bar Overview Kinematic Solution Curvature Theory Design Optimization Final Design