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This article has as the main subject the exoskeleton devices used in rehabilitation applications of the wrist joint for patients who are in the recovery period after suffering a stroke. Exoskeleton devices have some advantages compared to classic therapies, such as the possibility of performing rehabilitation exercises from the comfort of your own home. Therefore, in this article, a short state of the art with the main devices developed at the present time was carried out. By developing a structural analysis, it was shown that the parallel manipulator structures used for the development of the exoskeleton have 2 DoF, and they can contain RRU, RTU, or TRU connection legs. Next, the kinematic analysis of the structure with RRU connection legs is presented, from which the transmission function for the four-bar linkages was extracted. The study continues with the optimization of the synthesis in order to achieve a higher value for the minimum input transmission angle and a lower value for the total size area. Using the optimized results, a 3D prototype and the performance analysis were developed. The main conclusion of this article is that the presented 2-RRU-U parallel manipulator can be a suitable proposal for a rehabilitation exoskeleton-type device due to the optimization of the total size area and the higher value of the minimum input transmission angle. [ABSTRACT FROM AUTHOR]

This article has as the main subject the exoskeleton devices used in rehabilitation applications of the wrist joint for patients who are in the recovery period after suffering a stroke. Exoskeleton devices have some advantages compared to classic therapies, such as the possibility of performing rehabilitation exercises from the comfort of your own home. Therefore, in this article, a short state of the art with the main devices developed at the present time was carried out. By developing a structural analysis, it was shown that the parallel manipulator structures used for the development of the exoskeleton have 2 DoF, and they can contain RRU, RTU, or TRU connection legs. Next, the kinematic analysis of the structure with RRU connection legs is presented, from which the transmission function for the four-bar linkages was extracted. The study continues with the optimization of the synthesis in order to achieve a higher value for the minimum input transmission angle and a lower value for the total size area. Using the optimized results, a 3D prototype and the performance analysis were developed. The main conclusion of this article is that the presented 2-RRU-U parallel manipulator can be a suitable proposal for a rehabilitation exoskeleton-type device due to the optimization of the total size area and the higher value of the minimum input transmission angle.

Wrist exoskeletons are increasingly being used in the rehabilitation of stroke and hand dysfunction because of its ability to assist patients in high intensity, repetitive, targeted and interactive rehabilitation training. However, the existing wrist exoskeletons cannot effectively replace the work of therapist and improve hand function, mainly because the existing exoskeletons cannot assist patients to perform natural hand movement covering the entire physiological motor space (PMS). Here, we present a bioelectronic controlled hybrid serial-parallel wrist exoskeleton HrWr-ExoSkeleton (HrWE) which is based on the PMS design guidance, the gear set can carry out forearm pronation/supination (P/S) and the 2-DoF parallel configuration fixed on the gear set can carry out wrist flexion/extension (F/E) and radial/ulnar deviation (R/U). This special configuration not only provides enough range of motion (RoM) for rehabilitation training (85F/85E, 55R/55U, and 90P/90S), but also makes it easier to provide the interface for finger exoskeletons and be adapted to upper limb exoskeletons. In addition, to further improve the rehabilitation effect, we propose a HrWE-assisted active rehabilitation training platform based on surface electromyography signals.

This work focuses on the design and the validation of a wearable mechatronic device for an at-home assessment of wrist stiffness in patients affected by Parkinson’s Disease (PD). The device includes one actuated joint and four passive revolute joints with a high overall intrinsic backdriveability. In order to allow the user to freely move the wrist during activities of daily living, we implemented a transparent controller on the basis of the interaction force sensed by the embedded load cell. Conversely, in order to provide perturbations for estimating the wrist flexion-extension rigidity, we implemented a torque controller. Firstly, we report a pilot study that aimed at characterizing the device in terms of range of motion (ROM) allowed, transparency perceived and torque-tracking capability. Then, we present a case study in which we tested our device with seven PD patients in both drug-OFF and drug-ON conditions and we compared the measured stiffness with the one measured in fourteen healthy controls and with the outcome of the most used clinical scale (MDS-UPDRS). The device allowed to successfully estimate the stiffness as different depending on the movement direction. Indeed, extension stiffness was higher than the flexion one, accordingly to the literature. Moreover, the device allowed to discriminate both Healthy subjects from PD subjects, and PD subjects in OFF condition from PD subjects in ON condition. In conclusion, we demonstrate the feasibility of the device in measuring wrist rigidity, thus enabling the possibility to implement an at-home assessment of the PD rigidity. [ABSTRACT FROM AUTHOR]

To develop a wrist robotic exoskeleton-type interface (REI) for force interaction, it should have a suitable range of motion similar to human wrist activities of daily living, large torque output performance, and low moving parts inertia for dynamic motion response to cover the human behavior frequency. In this paper, a wrist REI based on a fully actuated coaxial spherical parallel mechanism (CSPM) is proposed to satisfy the aforementioned features. The fully actuated CSPM-based wrist REI (FC-WREI) has the characteristics of pure rotation similar to the human wrist, high torque output by parallel torque synthesis, and low moving parts inertia due to the base arrangement of the actuators. Due to the mechanical advantages and design optimization, the FC-WREI maximally provides torque as much as 56.49–130.43% of the maximum isometric torque of the human wrist, while providing a consistent range of motion to the human wrist without interference problem. Moreover, it is confirmed that the inertia of the FC-WREI is up to 5.35 times lower than similar devices. These advantages of the FC-WREI mean that the device is applicable to various fields of REIs for force interaction.

Objective: Prior to implementing any robotic device or new rehabilitation technique into clinical practice, it is essential to examine metrics that reflect the instrument's utility and range of action. For this purpose, this study assesses, based on biomechanical data, the ergonomics and action range of a wrist exoskeleton that may be implemented into clinical practice for the rehabilitation of this joint in patients with Parkinson' disease (PD). Materials and Methods: Eleven individuals with rigidity caused by PD participated in the study. Two distinct tasks were proposed: maximum voluntary contraction and sequential wrist flexion and extension; while electromyography and kinematic data were collected in two stages, with and without the exoskeleton. For statistical analysis, Bootstrap resampling, Kolmogorov-Smirnov, and paired Wilcoxon Mann tests were used. Results and Conclusion: Using the exoskeleton resulted in a 22% increase in muscle activation of the carpal extensors and a 9% decrease in wrist extension. According to the biomechanical parameters evaluated, the exoskeleton guaranteed the amplitude considered functional for the wrist joint, indicating good mechanical adequacy for use in clinical practice. • The use of exoskeletons has been used successfully for rehabilitation of neurological patients. • The functional joint movement was preserved during the use of the exoskeleton. • The use of the device causes a greater activation of motor units. • Patient care once the device can enable efficient wrist rehabilitation. • The robotic device standardizes the amplitude of wrist flexion/extension movements. [ABSTRACT FROM AUTHOR]

This paper proposes a multi-lateral shared control concept for robot assisted rehabilitation. In particular, a dual-user force-feedback teleoperation control architecture is implemented on a forearm-wrist rehabilitation system consisting of two kinematically dissimilar robotic devices. The multi-lateral rehabilitation system allows for patients to train with on-line virtual dynamic tasks in collaboration with a therapist. Different control authority can be assigned to each agent so that therapists can guide or evaluate movements of patients, or share the control with them. The collaboration is implemented using a dual-user force-feedback teleoperation control architecture, in which a dominance factor determines the authority of each agent in commanding the virtual task. The effectiveness of the controller and regulation of the dominance for each agent is experimentally verified. [ABSTRACT FROM AUTHOR]

To develop a wrist robotic exoskeleton-type interface (REI) for force interaction, it should have a suitable range of motion similar to human wrist activities of daily living, large torque output performance, and low moving parts inertia for dynamic motion response to cover the human behavior frequency. In this paper, a wrist REI based on a fully actuated coaxial spherical parallel mechanism (CSPM) is proposed to satisfy the aforementioned features. The fully actuated CSPM-based wrist REI (FC-WREI) has the characteristics of pure rotation similar to the human wrist, high torque output by parallel torque synthesis, and low moving parts inertia due to the base arrangement of the actuators. Due to the mechanical advantages and design optimization, the FC-WREI maximally provides torque as much as 56.49–130.43% of the maximum isometric torque of the human wrist, while providing a consistent range of motion to the human wrist without interference problem. Moreover, it is confirmed that the inertia of the FC-WREI is up to 5.35 times lower than similar devices. These advantages of the FC-WREI mean that the device is applicable to various fields of REIs for force interaction. [ABSTRACT FROM AUTHOR]