Approaches to human arm movement control—A review (original) (raw)
Related papers
IEEE Transactions on Medical Robotics and Bionics, 2021
Design and development of robotic-assistance must consider the abilities of individuals with disabilities. In this paper, a 8-DOF kinematic model of the upper limb complex is derived to evaluate the reachable workspace of the arm during interaction with a planar robot and to serve as the basis for rehabilitation strategies and assistive robotics. Through inverse differential kinematics and by taking account the physical limits of each arm joint, the model determines workspaces where the individual is able to perform tasks and those regions where robotic assistance is required. Next, a learning-from-demonstration strategy via a nonparametric potential field function is derived to teach the robot the required assistance based on demonstrations of functional tasks. The paper investigates two applications. First, in the context of rehabilitation, robotic assistance is only provided if the individual is required to move her arm in regions that are not reachable via voluntary motion. Second, in the context of assistive robotics, the demonstrated trajectory is scaled down to match the individual's voluntary range of motion through a nonlinear workspace mapping. Assistance is provided within that workspace only. Experimental results in 5 different experimental scenarios with a person with cerebral palsy confirm the suitability of the proposed framework.
Development of an Arm Rehabilitation System with Different Control Approaches
2017
Stroke rehabilitation plays a vital role for people with limb disability because of stroke attack. Due to gradually increasing medical prices, the cost of rehabilitation devices existed in the hospital and rehab centre are simultaneously increased. These devices also lack the features that help to ease and increase the spirit of patients during the rehabilitation process. Thus, this paper aim to create an arm platform-based for upper limb rehabilitation, where the interactive game features also created by using Unity 2D software for the purpose of motivating patients during the rehabilitation process. The main target is to develop an arm platform, which is focused on proper controller design for the active exercises in early-stage therapy. The performance of the arm platform is examined in term of range of motion. Therefore, it will reduce patient’s pressure during the exercise and gradually improve their agility. In the proper control of the muscle tension, the designed upper limb ...
Modeling of Human Motor Control and Its Application in Human Interaction with Machines
2018
Human civilization started with the invention of tools which enhanced and expanded human motor capability. With the recent development of virtual reality technology and artificial intelligence, the interaction between humans and machines has become more and more intricate. A better understanding of our motor system and the way it interacts with machines will allow us to better design intelligent devices. However, previous works in motor control modeling mostly focused on linear dynamics and had limitations in incorporating the process of learning. A musculoskeletal model based on mechanical principles and a motor control model based on Bayesian probability are proposed in this study. The probability-theoretical formulation of the problem not only facilitates the understanding of motor learning but also transforms nonlinear dynamics into linear problems. Using these models, the interactions in which both human and machine are capable of learning and adapting are formulated and analyz...
Command Trajectory of Fast Forearm Movements Estimated by Optimal Control Theory
Using optimal control theory and dynamic programming, we reconstructed the command trajectory of the fast elbow joint movement with two musculoskeletal models of the elbow joint, one with linear areflexic and the other with nonlinear reflexic muscle representation. The goal of the optimization was to seek a command trajectory that best reproduced the experimentally derived movement trajectory. The estimation results showed that the command trajectory using the model with linear areflexic muscle representation manifested the triphasic response, while the results using the model with nonlinear reflexic muscle representation showed only biphasic response. The calculated command trajectories capture the characteristics of the measured EMG. The results revealed that the optimal control theory could be used to reconstruct, from the joint angle trajectory, a command trajectory compatible with the currently accepted concept of motor control.
Quantitative evaluation of upper-limb motor control in robot-aided rehabilitation
Medical & Biological Engineering & Computing, 2011
This paper is focused on the multimodal analysis of patient performance, carried out by means of robotic technology and wearable sensors, and aims at providing quantitative measure of biomechanical and motion planning features of arm motor control following rehabilitation. Upper-limb robotic therapy was administered to 24 community-dwelling persons with chronic stroke. Performance indices on patient motor performance were computed from data recorded with the InMotion2 robotic machine and a magneto-inertial sensor. Motor planning issues were investigated by means of techniques of motion decomposition into submovements. A linear regression analysis was carried out to study correlation with clinical scales. Robotic outcome measures showed a significant improvement of kinematic motor performance; improvement of dynamic components was more significant in resistive motion and highly correlated with MP. The analysis of motion decomposition into submovements showed an important change with recovery of submovement number, amplitude and order, tending to patterns measured in healthy subjects. Preliminary results showed that arm biomechanical functions can be objectively measured by means of the proposed set of performance indices. Correlation with MP is high, while correlation with FM is moderate. Features related to motion planning strategies can be extracted from submovement analysis.
Stability and motor adaptation in human arm movements
Biological Cybernetics, 2006
In control, stability captures the reproducibility of motions and the robustness to environmental and internal perturbations. This paper examines how stability can be evaluated in human movements, and possible mechanisms by which humans ensure stability. First, a measure of stability is introduced, which is simple to apply to human movements and corresponds to Lyapunov exponents. Its application to real data shows that it is able to distinguish effectively between stable and unstable dynamics. A computational model is then used to investigate stability in human arm movements, which takes into account motor output variability and computes the force to perform a task according to an inverse dynamics model. Simulation results suggest that even a large time delay does not affect movement stability as long as the reflex feedback is small relative to muscle elasticity. Simulations are also used to demonstrate that existing learning schemes, using a monotonic antisymmetric update law, cannot compensate for unstable dynamics. An impedance compensation algorithm is introduced to learn unstable dynamics, which produces similar adaptation responses to those found in experiments.
Goal-directed arm movements. II: A kinematic model and its relation to EMG records
Journal of Electromyography and Kinesiology, 1993
In a previous study the EMG records of shoulder and elbow muscles during goal-directed arm movements were discussed. Here an analysis of the kinematic signals is presented and the relation between EMG and kinematic signals is assessed in a correlation analysis. The displacement as a function of time (movement trace) is analyzed. The movement trace is described by a model with five parameters that are estimated using a least squares criterion. Four parameters describe the timing of a triphasic muscular input and a fifth parameter describes neuromuscular dynamics. The parameters provide a means to compare the shape of movement traces recorded under different experimental conditions. After scaling, the shapes of movement traces with different step sizes and velocities/durations can be compared. The scaled parameters reveal a significant dependence on the movement direction of maximally fast movements. Furthermore, the scaled parameters depend significantly on the maximum velocity obtained by the subjects. This dependence can be interpreted in terms of neural inputs and muscular dynamics, as the parameters have been defined in these terms. The parameters estimated from the kinematics have a high correlation with EMG timing. A further analysis of these correlations indicates that the movement obtained is closely coupled to activity of the four prime movers of the upper arm and of three out of four scapular muscles.
Developing Models for Predicting Physiologically Impaired Arm Reaching Paths
World Academy of Science, Engineering and Technology, International Journal of Medical, Health, Biomedical, Bioengineering and Pharmaceutical Engineering, 2017
This paper describes the development of a model of an impaired human arm performing a reaching motion, which will be used to predict hand path trajectories for people with reduced arm joint mobility. Assuming that the arm was in contact with a surface during the entire movement, the contact conditions at the initial and final task locations were determined and used to generate the entire trajectory. The model was validated by comparing it to experimental data, which simulated an arm joint impairment by physically constraining the joint motion with a brace. Future research will include using the model in the development of physical training protocols that avoid early recruitment of “healthy” Degrees-OfFreedom (DOF) for reaching motions, thus facilitating an Active Range-Of-Motion Recovery (AROM) for a particular impaired joint. Keywords—Higher order kinematic specifications, human motor coordination, impaired movement, kinematic synthesis.