Research Projects:

Gait Enhancing Mobile Shoe: Gait Enhancing Mobile Shoe Certain types of central nervous system damage, such as stroke, can cause an asymmetric walking gait. One rehabilitation method uses a split-belt treadmill to help rehabilitate impaired individuals. The split-belt treadmill causes each leg to move at a different speed while in contact with the ground. The split-belt treadmill has been shown to help rehabilitate walking impaired individuals on the treadmill, but there is one distinct drawback; the corrected gait does not transfer well to walking over ground. To increase the gait transference to walking over ground, I designed and built a passive shoe that admits a motion similar to that felt when walking on a split-belt treadmill. The gait enhancing mobile shoe (GEMS) alters the wearer's gait by causing one foot to move backward during the stance phase while walking over ground. No external power is required since the shoe mechanically converts the wearer's downward and horizontal forces into a backward motion. This shoe allows a patient to walk over ground while experiencing the same gait altering effects as felt on a split-belt treadmill, which should aid in transferring the corrected gait to walking in natural environments. This work is funded by the Eunice Kennedy Shriver National Institute of Child Health & Human Development, NIH NICHD, award number R21HD066200 and is in collaboration with Amy Bastian at the Kennedy Krieger Institute and Erin Vasudevan at the Moss Rehabilitation Research Institute.

Asymmetric Passive Dynamic Walkers: Asymmetric Gait Passive dynamic walkers (PDW) are devices that are able to walk down a slope without any active feedback using gravity as the only energy source. In this research, we are examining asymmetric walking in a similar, but different approach, as the above Gait Enhancing Mobile Shoe Project. By changing one physical parameter on one of the two legs in the PDW, we can show a number of stable asymmetric gait patterns where one leg has a consistenty different step length than the other, as shown on the right. The figure on the right has the right knee moved up the leg. This asymmetric model of walking will enable us to test the effect of different physical changes on how individuals will alter their gait.

Bimanual Symmetric Motions: Types of symmetries Many daily tasks require that a person simultaneously use both hands, such as opening the lid on a jar or moving a large book. Such bimanual tasks are difficult for people who have a stroke, but the tight neural coupling across the body can potentially allow individuals to self-rehabilitate by physically coupling their hands. To examine potential methods for robot-assisted bimanual rehabilitation, we are performing haptic tracking experiments where individuals experience a trajectory on one hand and attempt to recreate it with their other hand. Despite the physical symmetries, the results show that joint space motions are more difficult to achieve than motions in the visually centered space.

Human-Robot-Human Interaction: HRH In many everyday tasks two people interact with each other. People move a large object, an instructor helps a student learn to swing a tennis racquet, and physical therapists help a patient learn to move correctly after an accident. Many of these tasks could potentially be replaced with a robot teaching an individual that task. A necessary first step is to understand human-human physical cooperation, so this research measures the haptic interaction of dyads jointly working on a task. This work has discovered that dyads are faster than individuals, dyad members temporally specialize, and similar key differences between human-human and human-robot interaction that should enable improved human-robot interaction.

Haptics (EML 4593/6930): Part of the Haptics class project is to build a haptic device and/or conduct psychophysical experiments. Here are a few photos of the demonstrations from Spring 2010, from Spring 2011, and from Spring 2012.