Leveraging Mechanical Resonance into Mobility and Recovery for Stroke Survivors: a Novel Rehabilitation Technique

The goal of this dissertation was the design, development, and evaluation of two novel rehabilitation devices that leverage the dynamics of resonant systems in order to provide assistance during exercise for individuals with severe motor impairment. The first device, called the Resonating Arm Exerciser (RAE), is a lever that attaches to the push rim of a manual wheelchair and uses elastic bands to create a resonant system. The second device also uses Lever-Actuated Resonance Assistance (LARA) to provide assistance during self-propelled overground ambulation in a lever-drive wheelchair.;I first review the mechanical design of RAE and a pilot study that verified individuals with severe arm impairment due to chronic stroke were able to intuitively find the resonant frequency of RAE (a phenomenon known as "resonance entrainment") and thus increase their range of motion. Exercise with RAE also led to significant reductions in arm impairment for this population after three weeks.;We also studied if resonance entrainment could be used to train healthy individuals to make movements with a desired timing. We found that while resonance entrainment conveys usable information about movement timing, it also distorts the perception of that timing, causing individuals to move too slowly outside of the resonant system.;I then report the results of a home-based test of RAE that compared self-guided exercise with the device to a time-matched dose of conventional, self-guided exercises. Here we found that home-based training with RAE was feasible and significantly reduced impairment without increasing pain or spasticity. Gains with RAE were comparable to those found with conventional training, and also included distal arm improvement.;Finally, I discuss the design of the LARA-based lever-drive wheelchair and a pilot study where eight volunteers with chronic stroke successfully used the device to drive overground and play novel computer games by modulating their movement amplitude during exercise. The resonance improved their performance in the games. This is the first evidence of the ability of individuals with severe impairment to use a lever-drive wheelchair. The use of mechanical resonance to provide assistance during exercise is an effective and practical technique for new rehabilitation devices.