Mechanical Design and Analysis of the End-Effector Finger Rehabilitation Robot (EFRR) for Stroke Patients

Preliminary study of a new macro-micro robot system for dental implant surgery: Design, development and control

BACKGROUND

This study aims to develop a new dental implant robotic system (DIRS) to relieve the burden and enhance the quality of dental implant surgery.

METHODS

The implanting actuator and system controller are two parts. The implanting actuator is designed on the basis of the RCM mechanism, with its kinematics modelled. Besides, a multi-DOF admittance control strategy and a hybrid position-admittance control strategy were designed, endowing the actuator with environmental compliance.

RESULTS

In force sensing, about 97% of mixed force/torque are eliminated. Then, 30 groups of implantation are done, of which 15 groups are simple implantation, while another 15 groups are force-based implantation. The results show that the average contact force/torque can be reduced by 73.03% and 62.66%, and the peak contact force/torque can be reduced by 68.26% and 50.46%.

CONCLUSIONS

The results of preliminary experiments validate the effectiveness of DIRS, which has great potential to assist dentists with higher efficiency, better quality, and lower burden.

Design of a Self-Aligning Four-Finger Exoskeleton for Finger Abduction/Adduction and Flexion/Extension Motion

For wearable four-finger exoskeletons, it is still a challenge to design the metacarpophalangeal (MCP)joint abduction/adduction (a/a) kinematic chain and achieve axes self-aligning. This paper proposes a novel exoskeleton for four fingers that features a high degree of dexterity enabling MCP joint flexion/extension (f/e) and a/a motion. Other features of the exoskeleton include a self-aligning mechanism that absorbs misalignment between the exoskeleton and human joints, the ability to accommodate fingers of different sizes, and a compact design that allows simultaneous a/a motion without interference. This paper presents the exoskeleton's kinematic model, optimizes the range of motion (ROM), and length of the exoskeleton linkage using the Genetic Algorithm. We compare the four-finger MCP joint's ROM and fingertip workspace with and without the exoskeleton. Our experiments show that the proposed exoskeleton has no significant impact on the natural ROM of the four-finger MCP joint, enables the fingers to cover an average of 82.96% of the original workspace, and can reach a significant portion of the fingertip workspace.

Interaction with a Hand Rehabilitation Exoskeleton in EMG-Driven Bilateral Therapy: Influence of Visual Biofeedback on the Users' Performance

The effectiveness of EMG biofeedback with neurorehabilitation robotic platforms has not been previously addressed. The present work evaluates the influence of an EMG-based visual biofeedback on the user performance when performing EMG-driven bilateral exercises with a robotic hand exoskeleton. Eighteen healthy subjects were asked to perform 1-min randomly generated sequences of hand gestures (rest, open and close) in four different conditions resulting from the combination of using or not (1) EMG-based visual biofeedback and (2) kinesthetic feedback from the exoskeleton movement. The user performance in each test was measured by computing similarity between the target gestures and the recognized user gestures using the L2 distance. Statistically significant differences in the subject performance were found in the type of provided feedback (p-value 0.0124). Pairwise comparisons showed that the L2 distance was statistically significantly lower when only EMG-based visual feedback was present (2.89 ± 0.71) than with the presence of the kinesthetic feedback alone (3.43 ± 0.75, p-value = 0.0412) or the combination of both (3.39 ± 0.70, p-value = 0.0497). Hence, EMG-based visual feedback enables subjects to increase their control over the movement of the robotic platform by assessing their muscle activation in real time. This type of feedback could benefit patients in learning more quickly how to activate robot functions, increasing their motivation towards rehabilitation.

Design and Control of Advanced Mechatronics Systems

Research and experiments on mechatronics systems, which are a synergistic integration of mechanical engineering, electronic control, and systems concepts, have contributed significantly to the design of systems, devices, processes, and products [...]

Mechanics Model-Based Motion Design for a Piggyback Nursing-Care Robot

To conduct a comfortable lift for the care-receiver, it takes a lot of time and operations to design the motion trajectory for each care-receiver before transfer tasks. To solve this problem, this paper proposed a method to design a lift trajectory for a piggyback transfer robot. The robot, which can lift and move a person from a wheelchair to a bed or a pedestal pan, has been developed. The trajectory obtained by this method could make the robot conduct a comfort lift for the care-receiver, according to the weight and height of the care-receiver. A human-robot mechanics model and the relationship between the comfortable lift trajectory and the care-receiver’s weight and height were also contributed. According to the test results of 20 subjects, the force parameters used for trajectory design were determined, and the trajectory design method was optimized. The results of three subjects demonstrated that this method could conveniently and quickly provide a robot lift trajectory based on the subject’s weight and height, and this trajectory also achieved a similar lift as the trajectory designed by relying on the opinion of the subject. This method can be used for the design of the reference trajectory in the compliant control of the piggyback robot, which realizes the comfortable lifting of the care-receiver.

Autonomous Exercise Generator for Upper Extremity Rehabilitation: A Fuzzy-Logic-Based Approach

In this paper, an autonomous exercise generation system based of fuzzy logic approach is presented. This work attempts to close a gap in the design of a completely autonomous robotic rehabilitation system that can recommend exercises to patients based on their data, such as shoulder range of motion (ROM) and muscle strength, from a pre-set library of exercises. The input parameters are fed into a system that uses Mamdani-style fuzzy logic rules to process them. In medical applications, the rationale behind decision making is a sophisticated process that involves a certain amount of uncertainty and ambiguity. In this instance, a fuzzy-logic-based system emerges as a viable option for dealing with the uncertainty. The system's rules have been reviewed by a therapist to ensure that it adheres to the relevant healthcare standards. Moreover, the system has been tested with a series of test data and the results obtained ensures the proposed idea's feasibility.