title: A configuration dependent muscle model for the myoelectric control of a transfemoral prosthesis.
abstract: This paper presents the development of a torque-based myoelectric impedance controller for an active-knee transfemoral prosthesis. An anthropomorphically inspired agonist-antagonist impedance controller studied in a myoelectric elbow prosthesis is adapted for the knee joint. To parameterize the controller, regression analysis was applied to a recently updated lower-extremity neuromuscular simulation model that provides estimates of knee torque as a function of knee angle and neural activation. Initial results using a constant moment arm suggest physically unreasonable parameters and poor model performance, but the inclusion of an angle-dependent moment arm in the reduced-order muscle model enables good correlation with the high-order neuromuscular model. The resulting limb controller is tested using a 1-DOF active knee prosthesis donned by a non-amputee subject with an able-bodied adapter. Initial treadmill walking tests demonstrate the potential of this controller to enable effective myoelectric control of the prosthetic limb.
authors.affiliation: Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York, USA. hoovercd@clarkson.edu
authors.forename: Carl D
authors.initials: CD
authors.lastname: Hoover
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Fite
mesh_terms: D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D006801:Humans; D007720:Knee Prosthesis; D008962:Models, Theoretical; D016138:Walking / Q000502:physiology