Several lower extremity exoskeletal systems have been developed for augmentation purpose. Common actuators, have important drawbacks such as complexity, and poor torque capacities. The main scope of this research is to propose a series elastic actuator for lower extremity exoskeletal system which was designed based on muscle functional analysis. For this purpose, a biomechanical framework consisting of a musculoskeletal model with ten degrees-of-freedom actuated by eighteen Hill-type musculotendon actuators per leg is utilized to perform the muscle functional analysis for common daily human activities. The simulation study illustrated functional differences between flexor and extensor muscles and the results were utilized for efficient design of the series elastic torque actuator employed in lower extremity exoskeletons.

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Background: Upper-extremity movement is limited in individuals with muscular weakness. This paper describes a novel, articulated upper-extremity orthosis, the Wilmington Robotic Exoskeleton (WREX), which helps people overcome this movement deficit.

Methods: This prospective, case-controlled study involved an ambulatory patient with arthrogryposis multiplex congenita and 2 nonambulatory patients with spinal muscular atrophy type II. The WREX uses elastic bands to negate the effects of gravity; it allows a person with neuromuscular weakness to move their arm in 3 dimensions. The WREX can be fixed on a brace for ambulatory patients and on the wheelchair for nonambulatory patients. Assessment was performed through motion analysis (with and without the WREX), clinical examination, and qualitative questionnaire.

Results: Motion analysis showed a marked improvement in upper-extremity function with the WREX. The questionnaire illustrated enhanced functionality with the WREX including self-feeding, fine motor control, and use of a television remote control. Enhanced functionality resulted in improved quality of life by increasing participation in school, raising self-esteem, and increasing social interaction. Two unexpected outcomes were increased security with trunk inclination and amelioration of the effects of contractures.

Conclusions: The WREX provided an increase in functionality and improved the quality of life of the patients. The device has become an integral part of the lives of the 3 patients.

Level of Evidence: Level III in Therapeutic Studies-Investigating the Results of Treatment.

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In this paper, a real-time upper limb’s motion tracking exoskeleton device is proposed and developed, which can be used in active rehabilitation of upper limb for stroke. This device is portable and wearable and is potential to be used in the passive and active training for stroke patients. Passive training has been finished in previous work and in this paper, the preliminary work for active rehabilitation is presented, which is realization of the real-time upper limb’s motion tracking. We use an adaptive weighted average filtering and double close-loop control to realize real-time and stable tracking performance. Experiments have been conducted to prove that it is suitable for active rehabilitation.

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This paper presents a novel 3-DOF optical force sensor for the wearable robotic arm. Precise sensing of human motion is still a challenge. As human motion detection sensors are expected to generate the real time data, with simultaneous measurement of multiple degrees of freedom. The optical sensing is considered to be standard for monitoring the human motion. The optical sensor is consists of high speed camera with integrated DSP (Digital Signal Processor). The DSP use to detect the changes in the sequence of frames to calculate the direction and displacement of its motion in a plane. On the other hand optical sensor eliminates the requirement of being in contact with the subject. Hand is the end-effecter of the arm and can be controlled by a 3-DOF (degree of freedom) shoulder, 2-DOF elbow and 2-DOF wrist joint. In this paper we present a new technique to measure the human’s hand movement in 3 dimensions translation frame. An intelligent computational method for this sensory system to measure the applied force is also developed. The optical force sensor was calibrated and then several experiments were conducted to check the feasibility of sensory system with the wearable robotic arm.

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