Mathematics Colloquia and Seminars

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Perhaps the most general principle underlying the control of locomotion is that animals move in a manner that minimizes energetic cost. Our recent research has demonstrated that animals accomplish this by beneficially combining prediction and optimization, relying on prediction to rapidly improve gait economy during changing contexts and optimization to accurately fine-tune the gait mechanics over time. Our research methods use controlled perturbations to the body, or its sensory inputs, to induce transient changes in locomotion mechanics. These changes allow us to identify the dynamics and contributions of the physiological processes underlying the control of energy minimization. We have designed, built, and used a number of devices to apply these perturbations including exoskeletons that reshape the energy landscape and test whether people continuously re-optimize cost. We have used a custom-built virtual reality system to perturb visual flow during treadmill walking to test the role of vision in the predictive control of energy minimization. Most recently, we have been perturbing sensed metabolic cost using a custom-built device to control the levels of oxygen and carbon dioxide within the blood during treadmill walking. My talk will focus on our energy minimization findings as well as a few of their applications including the real-time control of running speed.

mdonelan@sfu.ca; www.sfu.ca/locomotionlab