Type Synthesis of Self-Alignment Parallel Ankle Rehabilitation Robot with Suitable Passive Degrees of Freedom

The current parallel ankle rehabilitation robot(ARR)suffers from the problem of difficult real-time alignment of the human-robot joint center of rotation,which may lead to secondary injuries to the patient.This study investigates type synthesis of a parallel self-alignment ankle rehabilitation robot(PSAARR)based on the kinematic characteristics of ankle joint rotation center drift from the perspective of introducing"suitable passive degrees of freedom(DOF)"with a suitable number and form.First,the self-alignment principle of parallel ARR was proposed by deriving conditions for transforming a human-robot closed chain(HRCC)formed by an ARR and human body into a kinematic suitable constrained system and introducing conditions of"decoupled"and"less limb".Second,the relationship between the self-alignment principle and actuation wrenches(twists)of PSAARR was analyzed with the velocity Jacobian matrix as a"bridge".Subsequently,the type synthesis conditions of PSAARR were proposed.Third,a PSAARR synthesis method was proposed based on the screw theory and type of PSAARR synthesis conducted.Finally,an HRCC kinematic model was established to verify the self-alignment capability of the PSAARR.In this study,93 types of PSAARR limb structures were synthesized and the self-alignment capability of a human-robot joint axis was verified through kinematic analysis,which provides a theoretical basis for the design of such an ARR.

Smooth Trajectory Planning for a Cable Driven Parallel Waist Rehabilitation Robot Based on Rehabilitation Evaluation Factors

Rehabilitation robots can help physiatrists to assist patients in improving their movement ability.Due to the interaction between rehabilitation robots and patients,the robots need to complete rehabilitation training on a safe basis.This paper presents an approach for smooth trajectory planning for a cable-driven parallel waist rehabilitation robot(CDPWRR)based on the rehabilitation evaluation factors.First,motion capture technology is used to collect the motion data of several volunteers in waist twisting.Considering the impact of motion variability,the feature points at the center of the human pelvis are obtained after eliminating unreasonable data through rationality judgments.Then,point-to-point waist training trajectory planning based on quintic polynomial and cycloid functions,and multipoint waist training trajectory planning based on quintic B-spline functions are carried out.The corresponding planned curves and kinematics characteristics using three methods are compared and analyzed.Subsequently,the rehabilitation evaluation factors are introduced to conduct smooth trajectory planning for waist training,and the waist trajectory with better compliance is obtained based on the safety and feasibility of waist motion.Finally,the physical prototype of the CDPWRR is built,and the feasibility and effectiveness of the proposed smooth trajectory planning method are proved by numerical analysis and experiments.

New Hybrid AD Methodology for Minimizing the Total Amount of Information Content:A Case Study of Rehabilitation Robot Design

Converting customer needs into specific forms and providing consumers with services are crucial in product design.Currently,conversion is no longer difficult due to the development of modern technology,and various measures can be applied for product realization,thus increasing the complexity of analysis and evaluation in the design process.The focus of the design process has thus shifted from problem solving to minimizing the total amount of information content.This paper presents a New Hybrid Axiomatic Design(AD)Methodology based on iteratively matching and merging design parameters that meet the independence axiom and attribute constraints by applying trimming technology,the ideal final results,and technology evolution theory.The proposed method minimizes the total amount of information content and improves the design quality.Finally,a case study of a rehabilitation robot design for hemiplegic patients is presented.The results indicate that the iterative matching and merging of related attributes can minimize the total amount of information content,reduce the cost,and improve design efficiency.Additionally,evolutionary technology prediction can ensure product novelty and improve market competitiveness.The methodology provides an excellent way to design a new(or improved)product.

Development of a Wearable Upper Limb Rehabilitation Robot Based on Reinforced Soft Pneumatic Actuators

Dyskinesia of the upper limbs caused by stroke,sports injury,or trafc accidents limits the ability to perform the activities of daily living.Besides the necessary medical treatment,correct and scientifc rehabilitation training for the injured joint is an important auxiliary means during the treatment of the efected upper limb.Conventional upperlimb rehabilitation robots have some disadvantages,such as a complex structure,poor compliance,high cost,and poor portability.In this study,a novel soft wearable upper limb rehabilitation robot(SWULRR)with reinforced soft pneumatic actuators(RSPAs)that can withstand high pressure and featuring excellent loading characteristics was developed.Driven by RSPAs,this portable SWULRR can perform rehabilitation training of the wrist and elbow joints.In this study,the kinematics of an SWULRR were analyzed,and the force and motion characteristics of RSPA were studied experimentally.The results provide a reference for the development and application of wearable upper limb rehabilitation robots.An experimental study on the rotation angle of the wrist and the pressure of the RSPA was conducted to test the efect of the rehabilitation training and verify the rationality of the theoretical model.The process of wrist rehabilitation training was tested and evaluated,indicating that SWULRR with RSPAs will enhance the fexibility,comfort,and safety of rehabilitation training.This work is expected to promote the development of wearable upper-limb rehabilitation robots based on modular reinforced soft pneumatic actuators.

Fundamental problems in rehabilitation robots based on neuro-machine interaction

Study results in the last decades show that amount and quality of physical exercises,then the active participation,and now the cognitive involvement of patient in rehabilitation training are crucial to enhance recovery outcome of motor dysfunction patients after stroke.Rehabilitation robots mainly have been developed along this direction to satisfy requirements of recovery therapy,or focused on one or more of the above three points.Therefore,rehabilitation robot based on neuro-machine interaction has been proposed for the paralyzed limb training of post-stroke patient,which utilizes motor related EEG,UCSDI(Ultrasound Current Source Density Imaging),EMG for the robot control and feeds back the multi-sensory interaction information such as visual,auditory,force,haptic sensation to the patient simultaneously.This neuro-controlled and perceptual rehabilitation robot will bring great benefits to post-stroke patients.In order to develop such a kind of rehabilitation robot,some key technologies,such as non-invasive precise measurement and decoding of neural signals,realistic sensation feedback,coordinated control for both the rehabilitation robot and the patient,need to be solved.In this paper,some fundamental problems in developing and optimizing such a kind of rehabilitation robot based on neuro-machine interaction are proposed and discussed.

The design of exoskeleton lower limbs rehabilitation robot

To achieve human lower limbs rehabilitation training, the exoskeleton lower limbs rehabilitation robot is designed. Through respective motor driving, the retarding mechanism and telescopic adjusting mechanism, the function of human walking is accomplished. After the design of the mechanical structure, the finite element analysis is carried out on the important parts and the control system is achieved by Single Chip Microcomputer.

Overall design of the multifunctional walking rehabilitation robot

In this paper, it introduced the mechanical structure design of the multifunctional walking rehabilitation robot, We used the SolidWorks to design and assemble the rehabilitation robot, and optimized the rehabilitation robot based on ergonomics. The result shows that the multifunctional walking rehabilitation robot has the characteristics of complete functions, convenient operation, compact structure and so on. It can meet the requirements of medical care equipment, and effectively complete the nursing work of patients.

Observation on clinical application effect of ankle rehabilitation robot

Objective:The effect of ankle rehabilitation robot on joint movement of hemiplegic patients was studied and quantitatively evaluated.Methods 90 hemiplegic patients with lower limb dysfunction treated in our hospital from April 2017 to March 2019 were selected as subjects.The patients were randomly divided into two groups:control group(n=45)and observation group(n=45).The patients in the two groups received language training,physiotherapy,exercise therapy,spa,occupational therapy,massage and other comprehensive rehabilitation treatment,on the basis of which the observation group received the auxiliary intervention of ankle rehabilitation robot.The soft tissue compliance of the patients was evaluated by ankle metatarsal flexion moment before and after treatment,the metatarsal flexor tension was evaluated by modified Tardieu scale,and the clinical effect was evaluated by ankle active ankle dorsiflexion.Results After treatment,the ankle flexion angles(0°,10°,20°,30°)in the two groups were significantly lower than those in the control group(P<0.05).Results compared with before treatment,the ankle flexion angles(0°,10°,20°,30°)in the two groups were significantly lower than those in the control group(P<0.05).After treatment,the angle of R1 and R2 measured by modified Tardieu scale of ankle plantar flexor group increased significantly,and the difference of R2-R1 decreased significantly(P<0.05).The improvement degree of the observation group was significantly better than that of the control group(P<0.05).After treatment,the active ankle extension activity of the two groups was significantly higher than that before treatment(P<0.05),and the effective rate of the observation group was significantly higher than that of the observation group(P<0.05).Conclusion Auxiliary intervention with ankle rehabilitation robot system can effectively improve the compliance of ankle soft tissue in spastic hemiplegia,reduce the contracture of metatarsal flexor muscle and improve the disturbance of joint movement in a short time.At the same time,the degree of coordination and acceptance of patients and their families is high,which is an effective means to improve the therapeutic effect.

Digital Design of Multi-Functional Rehabilitation Robot

The mechanical structure as well as the schematic organization has been designed to achieve lower limb rehabilitation training function; Solidworks has been used to model the robot. And the robot has been optimized by the means of human-interference engineering. The primary components of the robot have been analyzed by Ansys workbench.

Multi-objective Optimization of a Parallel Ankle Rehabilitation Robot Using Modified Differential Evolution Algorithm

Dimensional synthesis is one of the most difficult issues in the field of parallel robots with actuation redundancy. To deal with the optimal design of a redundantly actuated parallel robot used for ankle rehabilitation, a methodology of dimensional synthesis based on multi-objective optimization is presented. First, the dimensional synthesis of the redundant parallel robot is formulated as a nonlinear constrained multi-objective optimization problem. Then four objective functions, separately reflecting occupied space, input/output transmission and torque performances, and multi-criteria constraints, such as dimension, interference and kinematics, are defined. In consideration of the passive exercise of plantar/dorsiflexion requiring large output moment, a torque index is proposed. To cope with the actuation redundancy of the parallel robot, a new output transmission index is defined as well. The multi-objective optimization problem is solved by using a modified Differential Evolution（DE） algorithm, which is characterized by new selection and mutation strategies. Meanwhile, a special penalty method is presented to tackle the multi-criteria constraints. Finally, numerical experiments for different optimization algorithms are implemented. The computation results show that the proposed indices of output transmission and torque, and constraint handling are effective for the redundant parallel robot; the modified DE algorithm is superior to the other tested algorithms, in terms of the ability of global search and the number of non-dominated solutions. The proposed methodology of multi-objective optimization can be also applied to the dimensional synthesis of other redundantly actuated parallel robots only with rotational movements.

Examination of the Effect of Rehabili-Mouse, a Desktop Rehabilitation Robot for Upper Limb Paresis after Stroke

Background: Active rehabilitation of the paralyzed limb is necessary for functional recovery from upper limb paralysis after stroke. In particular, the amount of training is very important, and robot rehabilitation is useful. However, most conventional robots are expensive, large, and stationary. We have developed Rehabili-Mouse, a new tabletop rehabilitation robot that is compact and portable. The purpose of this study was to conduct paralyzed upper limb training for a patient after stroke using Rehabili-Mouse and to examine its effect. Case: The patient was a 44-year-old man who had left-sided paresis after a right cerebral infarction, 3 months after onset. The training was carried out between February 2021 and March 2021 at Oyu Rehabilitation Hotspring Hospital. The training was 20 minutes of Rehabili-Mouse in addition to 40 minutes of usual occupational therapy and performed five times a week for four weeks. Upper limb functions were evaluated before and after the training, and two questionnaires of patient satisfaction with the device and the training were administered after the completion of the training. Upper limb function improved. The patient’s satisfaction with the device was poor, but his satisfaction with the training was good. Discussion: Training for the paralyzed upper limb after stroke using Rehabili-Mouse improved upper limb function and satisfied the trained patient. We plan to increase the number of cases and conduct further studies.

Adaptive patient-cooperative compliant control of lower limb rehabilitation robot

With the increase in the number of stroke patients,there is a growing demand for rehabilitation training.Robot-assisted training is expected to play a crucial role in meeting this demand.To ensure the safety and comfort of patients during rehabilitation training,it is important to have a patient-cooperative compliant control system for rehabilitation robots.In order to enhance the motion compliance of patients during rehabilitation training,a hierarchical adaptive patient-cooperative compliant control strategy that includes patient-passive exercise and patient-cooperative exercise is proposed.A low-level adaptive backstepping position controller is selected to ensure accurate tracking of the desired trajectory.At the high-level,an adaptive admittance controller is employed to plan the desired trajectory based on the interaction force between the patient and the robot.The results of the patient-robot cooperation experiment on a rehabilitation robot show a significant improvement in tracking trajectory,with a decrease of 76.45%in the dimensionless squared jerk(DSJ)and a decrease of 15.38%in the normalized root mean square deviation(NRMSD)when using the adaptive admittance controller.The proposed adaptive patient-cooperative control strategy effectively enhances the compliance of robot movements,thereby ensuring the safety and comfort of patients during rehabilitation training.

Motion Planning for a Cable-Driven Lower Limb Rehabilitation Robot with Movable Distal Anchor Points

This article introduces a cable-driven lower limb rehabilitation robot with movable distal anchor points(M-CDLR).The traditional cable-driven parallel robots(CDPRs)control the moving platform by changing the length of cables,M-CDLR can also adjust the position of the distal anchor point when the moving platform moves.The M-CDLR this article proposed has gait and single-leg training modes,which correspond to the plane and space motion of the moving platform,respectively.After introducing the system structure configuration,the generalized kinematics and dynamics of M-CDLR are established.The fully constrained CDPRs can provide more stable rehabilitation training than the under-constrained one but requires more cables.Therefore,a motion planning method for the movable distal anchor point of M-CDLR is proposed to realize the theoretically fully constrained with fewer cables.Then the expected trajectory of the moving platform is obtained from the motion capture experiment,and the motion planning of M-CDLR under two training modes is simulated.The simulation results verify the effectiveness of the proposed motion planning method.This study serves as a basic theoretical study of the structure optimization and control strategy of M-CDLR.

Adaptive neural tracking control for upper limb rehabilitation robot with output constraints

The authors investigate the trajectory tracking control problem of an upper limb reha-bilitation robot system with unknown dynamics.To address the system's uncertainties and improve the tracking accuracy of the rehabilitation robot,an adaptive neural full-state feedback control is proposed.The neural network is utilised to approximate the dy-namics that are not fully modelled and adapt to the interaction between the upper limb rehabilitation robot and the patient.By incorporating a high-gain observer,unmeasurable state information is integrated into the output feedback control.Taking into consider-ation the issue of joint position constraints during the actual rehabilitation training process,an adaptive neural full-state and output feedback control scheme with output constraint is further designed.From the perspective of safety in human–robot interaction during rehabilitation training,log-type barrier Lyapunov function is introduced in the output constraint controller to ensure that the output remains within the predefined constraint region.The stability of the closed-loop system is proved by Lyapunov stability theory.The effectiveness of the proposed control scheme is validated by applying it to an upper limb rehabilitation robot through simulations.

Progress in neurorehabilitation research and the support by the National Natural Science Foundation of China from 2010 to 2022

The National Natural Science Foundation of China is one of the major funding agencies for neuro rehabilitation research in China.This study reviews the frontier directions and achievements in the field of neurorehabilitation in China and wo rldwide.We used data from the Web of Science Core Collection(WoSCC) database to analyze the publications and data provided by the National Natural Science Foundation of China to analyze funding information.In addition,the prospects for neurorehabilitation research in China are discussed.From 2010 to 2022,a total of 74,220 publications in neurorehabilitation were identified,with there being an overall upward tendency.During this period,the National Natural Science Foundation of China has funded 476 research projects with a total funding of 192.38 million RMB to support neuro rehabilitation research in China.With the support of the National Natural Science Foundation of China,China has made some achievements in neurorehabilitation research.Research related to neurorehabilitation is believed to be making steady and significant progress in China.

Development and Evaluation of a Wearable Lower Limb Rehabilitation Robot

This paper introduces a rigid-flexible coupling wearable exoskeleton robot for lower limb,which is designed in light of gait biomechanics and beneficial for low limb movement disorders by implementing gait training.The rationality of the proposed mechanism is shown with the implementation of the dynamic simulation through MSC ADAMS.For the purposes of lightweight,the exoskeleton mechanism is optimized through finite element analysis.It can be concluded from performance evaluation experiment,the mechanism has certain advantages over existing exoskeleton robots,namely,comfortable,lightweight,low cost,which can be utilized for rehabilitation training in medical institutions or as a daily-walking ancillary equipment for patients.

Optimal Predictive Impedance Control in the Presence of Uncertainty for a Lower Limb Rehabilitation Robot

As an innovative concept,an optimal predictive impedance controlle is introduced here to control a lower limb rehabilitation robo in the presence of uncertainty.The desired impedance law is considered to propose a conventional model-based impedance controller for the LLRR.However,external disturbances,model imperfection,and parameters uncertainties reduce the performance of the controller in practice.In order to cope with these uncertainties,an optimal predictive compensator is introduced as a solution for a proposed convex optimization problem,which is performed on a forward finite-length horizon.As a result,the LLRR has the desired behavior even in an uncertain environment.The performance and efficiency of the proposed controller are verified by the simulation results.

Combined kinematic and static analysis of an articulated lower limb traction device for a rehabilitation robotic system

This paper presents a design of an articulated lower limb traction device(ALLTD) with joint torque generators for a cable-driven parallel rehabilitation robotic system(CDPRRS). An earlier version of the ALLTD uses a rigid link to model the lower limbs of a patient. This paper extends this scenario to include articulations in the lower limbs and analyzes the resulting two-link mechanism. Due to the force-displacement coupled structure, the inverse and forward kinematics of the ALLTD model are analyzed in combination with the requirement for static force balance. Examples using the limb parameters of Chinese adults are provided to show the efficacy of our model. The workspaces and cable tensions of the model indicate that the ALLTD could satisfy the rehabilitation training needs of patients with various lengths of lower limbs.

Design of Rehabilitation Robot with Combined Movement of Arms and Legs

Rehabilitation instruments are effective tools for patients to recover from disability. However, we still do not have a rehabilitation instrument which could provide combined movement with arms and legs. Rehabilitation with combined movement of arms and legs is completely a new method. In order to check the effect of this new rehabilitation method and to provide patients with more efficient rehabilitation instrument, we design a new rehabilitation robot. This robot lets patients practice when they lie down and stand up. This article explains the design of this instrument clearly. Using Unigraphics NX software to build 3D model, we have a complete design of this rehabilitation robot.

Safety Protection Method of Rehabilitation Robot Based on fNIRS and RGB-D Information Fusion

In order to improve the safety protection performance of the rehabilitation robot,an active safety protection method is proposed in the rehabilitation scene.The oxyhemoglobin concentration information and RGB-D information are combined in this method,which aims to realize the comprehensive monitoring of the invasion target,the patient’s brain function movement state,and the joint angle in the rehabilitation scene.The main focus is to study the fusion method of the oxyhemoglobin concentration information and RGB-D information in the rehabilitation scene.Frequency analysis of brain functional connectivity coefficient was used to distinguish the basic motion states.The human skeleton recognition algorithm was used to realize the angle monitoring of the upper limb joint combined with the depth information.Compared with speed and separation monitoring,the protection method of multi-information fusion is safer and more comprehensive for stroke patients.By building the active safety protection platform of the upper limb rehabilitation robot,the performance of the system in different safety states is tested,and the safety protection performance of the method in the upper limb rehabilitation scene is verified.