title: Characterizing and predicting submovements during human three-dimensional arm reaches.
abstract: We have demonstrated that 3D target-oriented human arm reaches can be represented as linear combinations of discrete submovements, where the submovements are a set of minimum-jerk basis functions for the reaches. We have also demonstrated the ability of deterministic feed-forward Artificial Neural Networks (ANNs) to predict the parameters of the submovements. ANNs were trained using kinematic data obtained experimentally from five human participants making target-directed movements that were decomposed offline into minimum-jerk submovements using an optimization algorithm. Under cross-validation, the ANNs were able to accurately predict the parameters (initiation-time, amplitude, and duration) of the individual submovements. We also demonstrated that the ANNs can together form a closed-loop model of human reaching capable of predicting 3D trajectories with VAF >95.9% and RMSE ≤4.32 cm relative to the actual recorded trajectories. This closed-loop model is a step towards a practical arm trajectory generator based on submovements, and should be useful for the development of future arm prosthetic devices that are controlled by brain computer interfaces or other user interfaces.
authors: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America; Cleveland Functional Electrical Stimulation Center, Cleveland, Ohio, United States of America.
authors: James Y
authors: JY
authors: Liao
authors: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States of America; Cleveland Functional Electrical Stimulation Center, Cleveland, Ohio, United States of America.
authors: Robert F
authors: RF
authors: Kirsch
mesh_terms: D000465:Algorithms; D001132:Arm / Q000033:anatomy & histology / Q000502:physiology*; D003198:Computer Simulation; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D009068:Movement; D016571:Neural Networks, Computer; D011237:Predictive Value of Tests