Robotic lower limb prosthesis design through simultaneous computer optimizations of human and prosthesis costs.
This webpage supports the following article about a computational formalism for designing robotic prosthesis through an optimization-based prediction of human movement during a simultaneously optimized prosthesis actuation.
Article
Citation: Matthew Handford and Manoj Srinivasan.Robotic lower limb prosthesis design through simultaneous computer optimizations of human and prosthesis costs.
Nature Scientific Reports, 6, 19983, 2016.
Authors: Matthew Handford and Manoj
Srinivasan
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Abstract
Robotic lower limb prostheses can improve the quality of life for amputees. Development of such devices, currently dominated by long prototyping periods, could be sped up by predictive simulations. In contrast to some amputee simulations which track experimentally determined non-amputee walking kinematics, here, we explicitly model the human-prosthesis interaction to produce a prediction of the user’s walking kinematics. We obtain simulations of an amputee using an ankle-foot prosthesis by simultaneously optimizing human movements and prosthesis actuation, minimizing a weighted sum of human metabolic and prosthesis costs. The resulting Pareto optimal solutions predict that increasing prosthesis energy cost, decreasing prosthesis mass, and allowing asymmetric gaits all decrease human metabolic rate for a given speed and alter human kinematics. The metabolic rates increase monotonically with speed. Remarkably, by performing an analogous optimization for a non-amputee human, we predict that an amputee walking with an appropriately optimized robotic prosthesis can have a lower metabolic cost – even lower than assuming that the non-amputee’s ankle torques are cost-free.Funding
Matthew Handford and Manoj Srinivasan were supported by NSF CMMI grant 1300655.
