Systems and method for volitional control of jointed mechanical device based on surface electromyography

Abstract

Systems and methods for controlling a weight bearing member having at least one powered joint are provided. A system includes a velocity reference module for receiving myoelectric control signals from a user during a non-weight bearing mode for the powered joint and generating a velocity reference for the powered joint based on the myoelectric control signals. The system further includes a volitional impedance module for generating a torque control signal for actuating the powered joint based at least on the velocity reference.

1 - 10 . (canceled) 
     
     
         11 . A myoelectric controller for a weight bearing member having a plurality of powered joints, comprising:
 a non-transitory computer-readable medium;   a velocity reference module stored in the computer-readable medium and configured for receiving myoelectric control signals from a user during a non-weight bearing mode for the plurality of powered joints and generating a velocity reference for an active one of the plurality of powered joints based on the myoelectric control signals;   a volitional impedance module stored in the computer-readable medium and configured for generating a torque control signal for actuating the active one of the plurality of powered joints based at least on the velocity reference; and   a selector module stored in the computer-readable medium and configured for alternating the active one of the plurality of powered joints when the myoelectric signals indicate a co-contraction.   
     
     
         12 . The myoelectric controller of  claim 11 , wherein the selector module alternates the active one of the plurality of powered joints when the myoelectric control signals indicating a co-contraction exceed a pre-determined threshold. 
     
     
         13 . The myoelectric controller of  claim 11 , wherein the selector module is further configured for generating, after the alternating, a signal for notifying the user as to which of the plurality of powered joints is active. 
     
     
         14 . A method for controlling at least one powered joint in a weight bearing member, comprising:
 receiving myoelectric control signals from a user during a non-weight bearing mode for the at least one powered joint;   generating a velocity reference for the at least one powered joint based on the myoelectric control signals; and   generating a torque control signal for actuating the at least one powered joint based at least on the velocity reference.   
     
     
         15 . The method of  claim 14 , wherein the torque control signal is generated using a model based on the behavior of a spring and dashpot element. 
     
     
         16 . The method of  claim 14 , wherein the velocity reference is further based on an intent of the user determined based on the myoelectric control signals. 
     
     
         17 . The method of  claim 16 , wherein the intent is determined based on one of quadratic discriminant analysis of the myoelectric control signals and linear discriminant analysis of the myoelectric control signals. 
     
     
         18 . The method of  claim 14 , wherein the velocity reference is generated based on a principal component analysis of the myoelectric control signals. 
     
     
         19 - 20 . (canceled) 
     
     
         21 . The method of  claim 14 , wherein the torque control signal is generated based on an equilibrium point derived from the velocity reference. 
     
     
         22 . The method of  claim 21 , further comprising determining the equilibrium point based at least one of the velocity reference or an initial angle of the at least one powered joint. 
     
     
         23 . The method of  claim 14 , wherein the at least one at least one powered joint comprises a plurality of powered joints, and further comprising alternating an active one of the plurality of powered joints when the myoelectric control signals indicate a co-contraction. 
     
     
         24 - 25 . (canceled) 
     
     
         26 . A jointed mechanical device, comprising:
 a weight bearing member comprising at least one powered joint; and   a controller for actuating the at least one powered joint,   wherein the controller is configured for actuating the at least one powered joint in at least one of a semi-autonomous weight bearing ‘mode or a non-weight bearing mode, the actuating of the at least one powered joint responsive to a myoelectric control signals.   
     
     
         27 . The jointed mechanical device of  claim 26 , wherein the controller generates a torque control signal for actuating the at least one powered joint during the non-weight bearing mode using a model based on a behavior of a spring and dashpot element and a velocity reference. 
     
     
         28 . The jointed mechanical device of  claim 26 , wherein the controller receives raw myoelectric signals from a user and processes the raw myoelectric signals to yield the myoelectric control signals. 
     
     
         29 . The jointed mechanical device of  claim 26 , wherein the weight bearing member comprises one of a limb prosthesis and a limb orthosis, 
     
     
         30 . The jointed mechanical device of  claim 26 , wherein the weight bearing member comprises a lower limb prosthesis, and wherein the at least one joint comprises at least one of a knee joint or an ankle joint. 
     
     
         31 . The jointed mechanical device of  claim 26 , wherein the non-weight bearing mode comprises sitting or non-weight bearing standing. 
     
     
         32 . The jointed mechanical device of  claim 26 , wherein the weight bearing member comprises a plurality of powered joints, wherein the controller further comprises a selector configured for alternating between the plurality of powered joints if the myoelectric control signals exceed a pre-determined threshold. 
     
     
         33 . The jointed mechanical device of  claim 32 , further comprising at least one feedback device for notifying a user as to which of the plurality of powered joints is currently selected. 
     
     
         34 - 36 . (canceled)