Stephen Sprigle, PhD, PT (School of Mechanical Engineering, Georgia Institute of Technology)
Aldo Ferri, PhD (School of Mechanical Engineering, Georgia Institute of Technology)
Frank Hammond III, PhD (School of Mechanical Engineering, Georgia Institute of Technology)
Ramakant Rambhatla, MBA (Vice President and Chief Engineer, Invacare Corp.)
Sharon Sonenblum, PhD (School of Mechanical Engineering, Georgia Institute of Technology)
Evaluation of Systemic Energy Losses in Manual Wheelchairs Using Intermittently-Propulsive Robotic Testbed
Mobility, independence, support, and safety all need to be balanced for a wheelchair to become a functional extension of the user. Ease of control and maneuverability are dictated by the mechanical efficiency; less efficient chairs require greater physical exertion, and repetitive and intense loads on the upper extremities can ultimately lead to injuries from overuse. Essentially, mechanical efficiency is reflective of the energetic propulsion effort to travel over-ground against frictional and inertial resistances. The 'optimal' wheel or frame choice is often unclear, especially because users have limited access to higher-end component options that are locked behind dated coding policies unrelated to performance, quality, or perceived value. The objective of this research is split into three aims: 1) to empirically characterize the cost of wheelchair propulsion, 2) to assess performance of various wheelchair configurations, and 3) to improve the current predictive dynamic model of wheelchair mobility to better emulate real-world use. This proposed work will require the Anatomical Model Propulsion System (AMPS), a robotic wheelchair-propelling apparatus that has been used to assess wheelchair performance in past studies. As human users utilize cyclic torque bursts to propel the chair, one goal of the proposed research is to reproduce this intermittently-propulsive behavior with the electromechanical AMPS to better imitate real-world use. The hypothesis is that intermittent propulsion and coasting deceleration will highlight frictional and inertial resistance differences between the wheelchairs. Ultimately, this research will help clinicians and manufacturers understand how configuration choices influence propulsive efforts to improve their classification techniques, and generally improve their existing design processes.