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The threshold control theory is applied to build a physiology-based FES controller. The proposed control strategy is tested in simulation study with an integrated musculoskeletal model. The results suggest that the controller based on the threshold control theory alone can realize the task with small feedback delays. However, it is not capable to produce the movement fast enough to match the desired...
A closed-loop virtual arm (VA) model has been developed in SIMULINK environment by adding spinal reflex circuits and propriospinal neural networks to the open-loop VA model developed in early study. An improved virtual muscle model (VM4.0) is used to speed up simulation and to generate more precise recruitment of muscle force at low levels of muscle activation. Time delays in the reflex loops are...
A typical prosthetic limb has sensory shortcomings, one of which is lack of kinesthesia. Conventional methods to evoke kinesthesia, which would be required for a precise control of prosthetic limbs, include tendon vibration and skin stretch, but these produce only the sensation of small movements. In this study, tendon vibration is extended to evoke sensations of a more rapid movement. A stimulation...
In this study, the sliding mode approach is applied to the tracking control problem of a planar arm manipulator system driven by a new type of actuator, which comprises a pneumatic muscle (PM) and a torsion spring. Unlike the traditional agonist/antagonist pneumatic muscle actuator, the PM is arranged in place of bicep and the torsion spring provides opposing torque in the presented actuator. The...
Individuals afflicted with Parkinson's disease (PD) have impaired force or torque control. It has also been reported that force or torque production, either dynamic or isometric, may be debilitated by PD in certain muscles and joints. During isometric contractions, the reported impairments were mostly in the rate of force changes, in latency, and in Maximum Voluntary Contraction (MVC) levels. However,...
We investigated muscle activation levels or patterns determined during two-joint arm movements. Twelve subjects were instructed to move their right (dominant) wrists in a horizontal plane. Surface electromyographic activities were recorded from the brachioradialis, biceps brachii, and triceps brachii. The muscle activation level was demonstrated as a function of both the elbow and shoulder torque...
Strengthening muscle force by training, e.g., an isokinetic exercise is used widely used method in the rehabilitation medicine and sports medicine. However, many conventional isokinetic exercise machines cannot be used safely and easily. In this study, we developed an isokinetic and iso-contractile exercise machine, named ldquoMEM-MRBrdquo, using an ldquoMR brakerdquo. This brake includes MR fluid...
Current commercial upper limb prostheses could be inadequate to satisfactorily rehabilitate those patients with a high level amputation that require a high functional autonomy in the everyday living. The aim of the study presented in this paper is the design of a new powered humeral rotator to be introduced in the current upper limb prosthesis available at our labs, which is also provided with a powered...
Andrews et. al. developed an indoor rowing system for paraplegia using functional electrical stimulation (FES), and presented that the system was safe and healthy for paraplegia. However, the system would be better if the following three terms are improved: Firstly, only quadriceps and hamstrings in both thighs are activated by FES. Secondly, in order to switch FES, it is required to push periodically...
Using FES for reanimation of paralyzed arm has been seriously considered by researchers in recent years. Due to complexities of reaching movement, utilization of a precise model, virtual reality capabilities and advanced control techniques is inevitable. This paper deals with a precise model of paralyzed arm for FES researches. Model elements exactly conform to the elements of the musculoskeletal...
A simple model representing the quasistatic behavior of skeletal muscle is presented in which the force produced by the muscle is a bilinear function of the muscle length and the neural activation of the muscle. Using two such muscles to represent the biceps and triceps, a biomechanical model of the elbow and forearm is developed. For maintenance of static posture of the elbow and forearm, this model...
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