Design Of Rehabilitation Robot Research Articles

Design and development of knee rehabilitation robot

This research presents a comprehensive design and analysis of a knee rehabilitation platform aimed at aiding individuals with knee dysfunction. Dysfunction in the knee joint can lead to an imbalance in gait and posture during activities of daily living (ADLs) such as standing, walking, and running. This study focuses on developing a 2-degree-of-freedom (2-DoF) knee rehabilitation device capable of mimicking linear and angular movements. A slider mechanism-based knee rehabilitation device is developed and simulated alongside various other mechanisms. The proposed mechanism achieves 32.5° of flexion for a linear movement of 0.45 m within 6 seconds, outperforming other mechanisms. To validate simulation results, a 3D-printed model is fabricated, and experimental studies are conducted under no-load conditions, showing close alignment with simulation outcomes with a deviation of ±5%. The device’s key features include portability, compliance, compactness, and enhanced stiffness. Future research will involve conducting pilot studies to further evaluate the practical efficacy and potential enhancements of the proposed knee rehabilitation platform.

Position–Force Control of a Lower-Limb Rehabilitation Robot Using a Force Feed-Forward and Compensative Gravity Proportional Derivative Method

The design and control of lower-limb rehabilitation robots for patients after a stroke has gained significant attention. This paper presents the dynamic analysis and control of a 3-degrees-of-freedom lower-limb rehabilitation robot using combined position–force control based on the force feed-forward and compensative gravity proportional derivative methods. In the lower-limb rehabilitation robot, the interaction force between the patient with the joints and links of the robot is uncertain and nonlinear due to the disturbance effect of Coriolis force, centrifugal force, gravitational force, and friction force. During recovery stages, the forces exerted by the patient’s lower limbs are also considered disturbances. Therefore, to meet the quality requirements in using the rehabilitation robot with different recovery stages of patient training, combining position control and force control is essential. In this paper, we proposed a combination of proportional–derivative gravity compensation motion control and force feed-forward control to form an advanced combined controller (position–force feed-forward control—PFFC) for a 3 DOF lower-limb functional rehabilitation robot. The forces can be sensed using a 3-axis force sensor. In addition, the robot’s position parameters are also measured by encoders. The control algorithm is implemented on the STM32F4 Discovery board. A verified test of the proposed control method is shown in the experiments, showing the good performance of the system.

Research on the prevention of joint and muscle injuries in competitive sports by scientific sports—Table tennis as an example

Table tennis is the most popular sport among all people, which damages every joints of the body to a certain extent, and is an example of scientific sports analysis and popularization. Analyzing the causes of joint and muscle injuries in table tennis and seeking effective preventive measures can not only reduce the incidence of sports injuries, but also ensure that athletes keep a high level of competitive state in high-intensity and long-term training and competition to a certain extent, and prolong their sports life. From two aspects of traditional sports injury prevention measures and the design of a multi-data fusion management rehabilitation robot, the prevention of muscle injury in competitive sports has been studied in depth.

Modeling, Simulation, and Kinematic Validation of Transfemoral Prosthetic Mechanism With Ankle Varus–Valgus Characteristic

Abstract Inspired by the kinesiology of human bionic joints, a transfemoral prosthetic mechanism based on a functional structure of parallel mechanism is developed for the transfemoral amputees. The walking interactive simulation is implemented based on human-prosthesis modeling to verify the kinematics of the designed prosthetic mechanism, as well as to explore compatibility between the amputees and prosthesis. Then, simulation-based prosthetic optimization is performed to pursue an optimized human-prosthesis model with economic metabolic consumption while eliminating compatibility errors including the joints' misalignment error between the affected limb and healthy limb, and the assembly error between human and prosthesis, so that the potential physical health problems can be avoided efficiently. This method is valuable for the optimal design of interactive rehabilitation robots. Finally, a developed proportional-integral-derivative-based (PID-based) finite-state machine (FSM) strategy is used, and the kinematic validation is carried out. The results show that the designed prosthesis possesses ankle varus–valgus characteristic, and it has a high human-like motion accuracy due to the FSM control can track prosthetic motion in each gait event. What's more, the prosthetic optimization can be an efficient method to enhance the biomechanical performance of human-prosthetic model so that the amputees have a more natural and symmetry gait.

Design and Validation of an Ambulatory User Support Gait Rehabilitation Robot: NIMBLE

Relearning to walk requires progressive training in real scenarios—overground—along with assistance in basic tasks, such as balancing. In addition, user ability must be maximized through compliant robotic assistance as needed. Despite decades of research, gait rehabilitation robotic devices yield controversial results. This article presents the conceptual design of a novel walking assistance and rehabilitation robot, the NIMBLE robot, aimed at providing ambulatory, bodyweight-supported gait training, assisting the user’s center of mass trajectory to aid weight transfer and dynamic balance during walking. NIMBLE consists of a robotic mobile frame, a partial bodyweight support (PBWS) system, an ambulatory lower-limb exoskeleton (Exo-H3) and a cable-driven pelvis-assisting robot. Designed as a modular structure, it differentiates hierarchical communication levels through a Robot Operating System (ROS) 2 network. We present the mechatronic design and experimental results assessing the impact of the mechatronic coupling between the robotic modules on the walking kinematics and the frame movement control performance. The robotic frame hardly affects the walking kinematics up to 2 degrees in both the sagittal and frontal planes, making it feasible for lateral balance and weight translation training. Moreover, it successfully tracks and follows user trajectories. The NIMBLE robotic frame assessment shows promising results for ambulatory gait rehabilitation.

Finger Multi-Joint Trajectory Measurement and Kinematics Analysis Based on Machine Vision

A method for measuring multi-joint finger trajectories is proposed using MediaPipe. In this method, a high-speed camera is used to record finger movements. Subsequently, the recorded finger movement data are input into MediaPipe, where the system automatically extracts the coordinate data of the key points in the finger movements. From this, we obtain data pertaining to the trajectory of the finger movements. In order to verify the accuracy and effectiveness of this experimental method, we compared it with the DH method and the Artificial keypoint alignment method in terms of metrics such as MAPE (Mean Absolute Percentage Error), maximum distance error, and the time taken to process 500 images. The results demonstrated that our method can detect multiple finger joints in a natural, efficient, and accurate manner. Then, we measured posture for three selected hand movements. We determined the position coordinates of the joints and calculated the angular acceleration of the joint rotation. We observed that the angular acceleration can fluctuate significantly over a very short period of time (less than 100 ms), in some cases increasing to more than ten times the initial acceleration. This finding underscores the complexity of finger joint movements. This study can provide support and reference for the design of finger rehabilitation robots and dexterous hands.

DESIGN, DEVELOPMENT AND HYBRID IMPEDANCE CONTROL OF AN ANKLE REHABILITATION ROBOT

DESIGN, DEVELOPMENT AND HYBRID IMPEDANCE CONTROL OF AN ANKLE REHABILITATION ROBOT

Design and Control of a Novel 6-DOF Desktop Upper Limb Rehabilitation Robot

Abstract This paper presents the design, analysis, and development of a Novel six degrees of freedom (6-DOF) desktop upper limb rehabilitation robot. The upper limb rehabilitation robot is mainly composed of the Omnidirectional mobile platform, armrest, and 3-DOF wrist rehabilitation mechanism. The forward and inverse kinematics and Jacobian matrix of the upper limb rehabilitation robot are derived based on the kinematics of a rigid body, and its working space is analyzed based on arm kinematics as well. The forward and inverse kinematics of the arm are derived based on the D-H method. A new control strategy and control algorithm were developed based on the hardware structure of the robot system and arm model, and the control strategy and control algorithm are used to carry out the simulated rehabilitation experiment on a single joint of the arm and the simulated rehabilitation experiment on multiple joint linkages in the arm. The experimental results show that the maximum error in the simulated rehabilitation experiment on a single joint of the arm is 6.123 deg, and the maximum error in the simulated rehabilitation experiment of multiple joint linkages in the arm is 5.323 deg. Therefore, the control strategy and control algorithm can complete the corresponding rehabilitation training. This 6-DOF desktop upper limb rehabilitation robot can provide passive rehabilitation training for patients in the early stages of paralysis.

Current research on exoskeletal lower limb rehabilitation robots

Stroke is characterized by a high incidence rate, and walking is one of the essential human functions. Lower limb rehabilitation robots can offer safe and effective walking training to patients with walking impairments caused by conditions such as neural injuries, aiding in their recovery or assisting in walking. For the needs of patients themselves, restoring their physical state and motor function as much as possible is the primary purpose of rehabilitation, and rehabilitation efficiency is an important factor affecting the quality of life of patients after surgery. Research on exoskeleton robots varies both domestically and internationally, each with its own unique characteristics and features. This paper outlines the design of lower limb rehabilitation robots based on gait analysis and control methods. It also provides an overview of the current state of research on lower limb exoskeleton robots in terms of degrees of freedom, actuation methods, and clinical applications. Furthermore, it offers insights into future directions for research on lower limb exoskeleton robots.

Research on Mechanical Leg Structure Design and Control System of Lower Limb Exoskeleton Rehabilitation Robot Based on Magnetorheological Variable Stiffness and Damping Actuator

During the walking process of lower limb exoskeleton rehabilitation robots, inevitable collision impacts will occur when the swinging leg lands on the ground. The impact reaction force from the ground will induce vibrations in the entire robot’s body from bottom to top. To address this phenomenon, considering the limitations of traditional active compliance and passive compliance methods, a variable stiffness and damping actuator (VSDA) leg structure using a magnetorheological damper (MRD) is proposed. Firstly, experimental methods are used to obtain the ground reaction force (GRF) exerted on a normal person during walking. Then, a mathematical model of the VSDA leg structure is constructed, and its working principle is analyzed. Based on human mass and dimensions, a 3D model is designed and selected. Finally, a simulation model is built in the MATLAB/Simulink environment using the fuzzy switch damping control strategy to simulate the acceleration and displacement of the human body under sinusoidal and random excitations. The results indicate that under sinusoidal excitation, employing fuzzy switch damping control optimizes human displacement by 72.47% compared to the high stiffness and high damping system, and by 16.95% compared to the switch damping system. Human acceleration is optimized by 52.09% compared to the high stiffness and high damping system, and by 25.2% compared to the switch damping system. Under random excitation, adopting fuzzy switch damping control optimizes human displacement by 59.09% compared to the high stiffness and high damping system, and by 21.74% compared to the switch damping system. Human acceleration is optimized by 78.74% compared to the high stiffness and high damping system, and by 31.66% compared to the switch damping system. This validates the VSDA design structure and control method, demonstrating certain advantages in improving the compliance and stability of lower limb exoskeleton rehabilitation robots.

Structural design and research of a novel lower limb rehabilitation robot for human–robot coupling

A bedside rehabilitation robot is developed to address the challenge of motor rehabilitation for patients with lower limb paralysis. Firstly, based on the principles of physical rehabilitation, a two-link planar robot model is used to simulate both the robot and human lower limbs, and the coupling characteristics between the human and robot are thoroughly analyzed. Then, the lower limb rehabilitation robot, fitted with an end-effector and ankle wearable feature, is designed according to the structural parameters. To enhance patient safety during rehabilitation, the device incorporates a freely rotating leg support mechanism that reduces the load on the ankle due to gravitational forces, and a two-stage series elastic mechanism is integrated below the foot support to provide a passive compliant output of robot power, allowing for more natural movement and reducing the risk of injury. Secondly, dynamic modeling is used to determine the dynamic parameters of the robot by conducting simulation calculations based on the inertia parameters of the human body and the robot model design parameters. Finally, an experimental platform is established using the structural and dynamic parameters, and the robot’s reliability is validated through experimentation. Results indicate that the robot can accurately complete passive rehabilitation training tasks, and the dynamic parameters meet the expected requirements.

Design and feasibility analysis of magnetorheological flexible joint for upper limb rehabilitation

Traditional upper limb rehabilitation robots have several disadvantageous. For example, they can only conduct rehabilitation training along predetermined trajectories, their safety systems are unreliable, and they lack the ability to adjust or train the affected limb based on the expected torque of the human body. To overcome these limitations, this study proposes a flexible safety system for joint rehabilitation utilising magnetorheological (MR) fluid. MR damper inverters offer significant advantages, including high torque, rapid response, controllable flexibility, and safety assurance. The range of motion trajectories can be adjusted using a four-lever hinge mechanism. The necessary driving force is provided by the motor actuator, and the MR damper imparts flexibility and variable damping characteristics to the output torque. The system uses a force/position impedance safety-control method, and using an internal position closed-loop controller, the MR upper limb rehabilitation flexible joint guides the affected limb to a safe position. A simulation is performed to verify the accuracy of the system’s motion torque and position. Extensive research has been conducted on the safe rehabilitation outcomes of the upper limb rehabilitation system under three working conditions (step, incremental, and equation) involving the interaction moment of the affected limb. Simulation and experimental results demonstrate that the MR damper effectively controls the upper limb rehabilitation system to achieve the desired results, even when subjected to incremental and abrupt interaction forces from the patient. The tracking accuracy error remains within the range of 3%–7% for a certain period, confirming the safety and feasibility of the MR-based upper limb rehabilitation robot design.

Design and Human-Robot Coupling Performance Analysis of Flexible Ankle Rehabilitation Robot

Design and Human-Robot Coupling Performance Analysis of Flexible Ankle Rehabilitation Robot

Purpose-centered design of rehabilitation robots: a case study of a hand exoskeleton for assessing spasticity

Hand exoskeletons offer promising solutions for hand function rehabilitation. Despite considerable research on novel exoskeleton technologies and the commercial availability of many hand exoskeletons, most hand exoskeletons can only perform motor training and assistance, rather than treatment or diagnosis of hand diseases. This limitation is also observed in other rehabilitation robots. Designing a rehabilitation robot for medical purposes necessitates the integration of existing technologies, tailored to the symptoms, clinical conditions, and management methods of the target disease. To facilitate such design, this study presents a design strategy for rehabilitation robots that assist in the therapy and assessment of specific diseases. The strategy first systematically gathers prior medical and engineering knowledge on the management of the target disease and clarifies comprehensive design requirements, including medical goals and user needs. Next, modified Quality Function Deployment (QFD) and Theory of Inventive Problem Solving (TRIZ) methods are used to identify the core requirements and the optimal design scheme based on existing technical solutions. Lastly, the optimal design scheme is prototyped, tested, and refined iteratively until the product satisfies the design purpose. As an illustrative case study of this design strategy, the design of a hand exoskeleton for assessing hand spasticity is discussed. This strategy is adaptable for designing hand exoskeletons for other diseases or developing other types of rehabilitation robots, thereby extending the potential of rehabilitation robots in diagnostic and therapeutic applications.

Configuration Design and Kinematic Performance Analysis of a Novel 4-DOF Parallel Ankle Rehabilitation Mechanism with Two Virtual Motion Centers

Aiming at the problem that the existing ankle rehabilitation robot is difficult to fully fit the complex motion of human ankle joint and has poor human-machine motion compatibility, an equivalent series mechanism model that is highly matched with the actual bone structure of the human ankle joint is proposed and mapped into a parallel rehabilitation mechanism. The parallel rehabilitation mechanism has two virtual motion centers (VMCs), which can simulate the complex motion of the ankle joint, adapt to the individual differences of various patients, and can meet the rehabilitation needs of both left and right feet of patients. Firstly, based on the motion properties and physiological structure of the human ankle joint, the mapping relationship between the rehabilitation mechanism and ankle joint is determined, and the series equivalent model of the ankle joint is established. According to the kinematic and constraint properties of the ankle equivalent model, the configuration design of the parallel ankle rehabilitation robot is carried out. Secondly, according to the intersecting motion planes theory, the full-cycle mobility of the mechanism is proved, and the continuous axis of the mechanism is judged based on the constraint power and its derivative. Then, the kinematics of the parallel ankle rehabilitation robot is analyzed. Finally, based on the OpenSim biomechanical software, a human-machine coupling rehabilitation simulation model is established to evaluate the rehabilitation effect, which lays the foundation for the formulation of a rehabilitation strategy for the later prototype.

User Experience Evaluation of Upper Limb Rehabilitation Robots: Implications for Design Optimization: A Pilot Study.

With the development of science and technology, people are trying to use robots to assist in stroke rehabilitation training. This study aims to analyze the result of the formative test to provide the orientation of upper limb rehabilitation robot design optimization. We invited 21 physical therapists (PTs) and eight occupational therapists (OTs) who had no experience operating any upper limb rehabilitation robots before, and 4 PTs and 1 OT who had experience operating upper limb rehabilitation robots. Data statistics use the Likert scale. The general group scored 3.5 for safety-related topics, while the experience group scored 4.5. In applicability-related questions, the main function score was 2.3 in the general group and 2.4 in the experience group; and the training trajectory score was 3.5 in the general group and 5.0 in the experience group. The overall ease of use score was 3.1 in the general group and 3.6 in the experience group. There was no statistical difference between the two groups. The methods to retouch the trajectory can be designed through the feedback collected in the formative test and gathering further detail in the next test. Further details about the smooth trajectory must be confirmed in the next test. The optimization of the recording process is also important to prevent users from making additional effort to know it well.

Mechanism Design and Control of Shoulder Rehabilitation Robots: A Review

Mechanism Design and Control of Shoulder Rehabilitation Robots: A Review

Design and Analysis of an Upper Limb Rehabilitation Robot Based on Multimodal Control

To address the rehabilitation needs of upper limb hemiplegic patients in various stages of recovery, streamline the workload of rehabilitation professionals, and provide data visualization, our research team designed a six-degree-of-freedom upper limb exoskeleton rehabilitation robot inspired by the human upper limb’s structure. We also developed an eight-channel synchronized signal acquisition system for capturing surface electromyography (sEMG) signals and elbow joint angle data. Utilizing Solidworks, we modeled the robot with a focus on modularity, and conducted structural and kinematic analyses. To predict the elbow joint angles, we employed a back propagation neural network (BPNN). We introduced three training modes: a PID control, bilateral control, and active control, each tailored to different phases of the rehabilitation process. Our experimental results demonstrated a strong linear regression relationship between the predicted reference values and the actual elbow joint angles, with an R-squared value of 94.41% and an average error of four degrees. Furthermore, these results validated the increased stability of our model and addressed issues related to the size and single-mode limitations of upper limb rehabilitation robots. This work lays the theoretical foundation for future model enhancements and further research in the field of rehabilitation.

Bionic Design of a Novel Portable Hand-Elbow Coordinate Exoskeleton for Activities of Daily Living

This paper presents the mechanical design and test of a portable hand-elbow combination linkage upper limb rehabilitation robot, which can realize the joint movement of the hand joint and elbow joint and reproduce the complete grasping action. The joints that need bionic support are determined according to the characteristics of human upper limbs and hands, and the overall bionic mechanism is designed. The Motion module in SolidWorks is used to simulate and analyze the rehabilitation robot. The measurement experiment and grasping experiment of joint mobility are carried out on the experimental prototype. As a result, the angular displacement and linear displacement curves obtained via the simulation results are smooth. The measurement experiment of the joint range of motion confirms that the joint range of motion is also within the range of the normal joint angle of the human body, and the grasping experiment shows that the exoskeleton can grasp and lift a 1.801-kg cylindrical object and other daily necessities of different shapes. This result shows that the design of the portable hand-elbow combination linkage upper limb rehabilitation robot is reasonable, can satisfy the rehabilitation training requirements of the hand and upper limb, and has some ability to assist users in daily life.

Design and Analysis of a Supine Ankle Rehabilitation Robot for Early Stroke Recovery

Existing ankle rehabilitation robots are large, difficult to move, and mostly designed for seated use, which cannot meet the early bedridden rehabilitation goals of stroke patients. To address these issues, a supine ankle rehabilitation robot (S-ARR) specifically designed for early bedridden rehabilitation of stroke patients has been proposed. The S-ARR is designed to be easily movable and adaptable to different heights. It features a variable workspace with mechanical limiters at the rotating joints. A kinematic model has been constructed, and the kinematic simulation of the S-ARR has been analyzed. A control system scheme for the S-ARR has been proposed. Additionally, experiments have been conducted on the prototype to measure joint range of motion and perform rehabilitation exercises. The simulation and experimental results demonstrate that the S-ARR has a feasible workspace and a relatively smooth motion process, enabling it to achieve supine ankle rehabilitation training. This indicates that the design of the supine ankle rehabilitation robot is reasonable, capable of meeting the requirements for ankle joint rehabilitation training, and has practical utility.