Development of a Hand Exoskeleton System for Index Finger Rehabilitation

In order to overcome the drawbacks of traditional rehabilitation method,the robot-aided rehabilitation has been widely investigated for the recent years.And the hand rehabilitation robot,as one of the hot research fields,remains many challenging issues to be investigated.This paper presents a new hand exoskeleton system with some novel characteristics.Firstly,both active and passive rehabilitative motions are realized.Secondly,the device is elaborately designed and brings advantages in many aspects.For example,joint motion is accomplished by a parallelogram mechanism and high level motion control is therefore made very simple without the need of complicated kinematics.The adjustable joint limit design ensures that the actual joint angles don＇t exceed the joint range of motion（ROM） and thus the patient safety is guaranteed.This design can fit to the different patients with different joint ROM as well as to the dynamically changing ROM for individual patient.The device can also accommodate to some extent variety of hand sizes.Thirdly,the proposed control strategy simultaneously realizes the position control and force control with the motor driver which only works in force control mode.Meanwhile,the system resistance compensation is preliminary realized and the resisting force is effectively reduced.Some experiments were conducted to verify the proposed system.Experimentally collected data show that the achieved ROM is close to that of a healthy hand and the range of phalange length（ROPL） covers the size of a typical hand,satisfying the size need of regular hand rehabilitation.In order to evaluate the performance when it works as a haptic device in active mode,the equivalent moment of inertia（MOI） of the device was calculated.The results prove that the device has low inertia which is critical in order to obtain good backdrivability.The experiments also show that in the active mode the virtual interactive force is successfully feedback to the finger and the resistance is reduced by one-third;for the passive control mode,the desired trajectory is realized satisfactorily.

Clinical Value of Musculoskeletal Ultrasound in Rehabilitation After Flexor Tendon Rupture Repair of the Hand

Objective:To explore the application effect and clinical value of musculoskeletal ultrasound in the rehabilitation of hand function after flexor tendon rupture repair.Methods:In this study,72 patients were selected from among patients who underwent flexor tendon rupture repair of the hand in Yancheng Third People’s Hospital from May 2018 to May 2020;the patients were randomly divided into the control group(routine hand rehabilitation training)and the experimental group(musculoskeletal ultrasound and targeted hand rehabilitation training based on examination results)by die roll,with 34 cases in each group;the hand rehabilitation of the two groups were compared.Results:The excellent and good rate of the total active motion(TAM)of the experimental group(94.44%)was significantly higher than that of the control group(69.44%)(P<0.05);before treatment,there was no significant difference in the diameter and degree of stenosis of the artery in the finger between the two groups(P>0.05);after treatment,the degree of stenosis and the diameter of the artery of the experimental group were significantly better than those of the control group(P<0.05).Conclusion:For patients treated with flexor tendon rupture repair of the hand,the use of musculoskeletal ultrasound in the rehabilitation process can significantly improve the functional recovery of the hand;therefore,it is worthy of in-depth research,promotion,and application in clinical rehabilitation.

Research on Key Technologies of Hand Function Rehabilitation Training Evaluation System Based on Leap Motion

This paper proposes an immersive training system for patients with hand dysfunction who can perform rehabilitation training independently. The system uses Leap Motion binocular vision sensors to collect human hand information, and uses the improved PCA (Principal Component Analysis) to perform data fusion on the real-time data collected by the sensor to obtain more hands with fewer principal components, and improve the stability and accuracy of the data. Immediately, the use of improved SVM (Support Vector Machine) and KNN (K-Nearest Neighbor Algorithm) for gesture recognition and classification is proposed to enable patients to perform rehabilitation training more effectively. Finally, the effective evaluation results of the rehabilitation effect of patients by the idea of AHP (Analytic Hierarchy Process) are taken as necessary reference factors for doctors to follow up treatment. Various experimental results show that the system has achieved the expected results and has a good application prospect.

RLSESN-based PID adaptive control for a novel wearable rehabilitation robotic hand driven by PM-TS actuators

Purpose-The purpose of this paper is to develop a novel wearable rehabilitation robotic hand driven by Pneumatic Muscle-Torsion Spring(PM-TS)for finger therapy.PM has complex nonlinear dynamics,which makes PM modelling difficult.To realize high-accurate tracking for the robotic hand,an Echo State Network(ESN)-based PID adaptive controller is proposed,even though the plant model is unknown.Design/methodology/approach-To drive a single joint of rehabilitation robotic hand,the paper proposes a new PM-TS actuator comprising a Pneumatic Muscle(PM)and a Torsion Spring(TS).Based on the novel actuator,a wearable robotic hand is designed.By employing the model-free approximation capability of ESN,the RLSESN based PID adaptive controller is presented for improving the trajectory tracking performance of the rehabilitation robotic hand.An ESN together with Recursive Least Square(RLS)is called a RLSESN,where the ESN output weight matrix is updated by the online RLS learning algorithm.Findings–Practical experiments demonstrate the validity of the PM-TS actuator and indicate that the performance of the RLSESN based PID adaptive controller is better than that of the conventional PID controller.In addition,they also verify the effectiveness of the proposed rehabilitation robotic hand.Originality/value–A new PM-TS actuator configuration that uses a PM and a torsion spring for bi-directional movement of joint is presented.By utilizing the new PM-TS actuator,a novel wearable rehabilitation robotic hand for finger therapy is designed.Based on the unknown plant model,the RLSESN_PID controller is proposed to attain satisfactory performance.

Analysis of Finger Muscular Forces using a Wearable Hand Exoskeleton System

In this paper, the finger muscular forces were estimated and analyzed through the application of inverse dynamics-based static optimization, and a hand exoskeleton system was designed to pull the fingers and measure the dynamics of the hand. To solve the static optimization, a muscular model of the hand flexors was derived. The experimental protocol was devised to analyze finger flexors in order to evaluate spasticity of the clenched fingers; muscular forces were estimated while the flexed fingers were extended by the exoskeleton with external loads applied. To measure the finger joint angles, the hand exoskeleton system was designed using four-bar linkage structure and potentiometers. In addition, the external loads to the fingertips were generated by cable driven actuators and simultaneously measured by loadcells which were located at each phalanx. The ex- periments were performed with a normal person and the muscular forces estimation results were discussed with reference to the physical phenomena.

Development of a Hand Exoskeleton System for Quantitative Analysis of Hand Functions

This paper proposes a hand exoskeleton system for evaluating hand functions. To evaluate hand functions, the hand exoskeleton system must be able to pull each finger joint, measure the finger joint angle and exerted force on the finger simultaneously. The proposed device uses serially connected 4-bar linkage structures, which have two embedded actuators with encoders and two loadcells per finger, to move each phalanx independently and measure the finger joint angles. A modular design was used for the exoskeleton, to facilitate the removal of unnecessary modules in different experiments and improve convenience. Silicon was used on the surface of the worn part to reduce the skin irritation that results from prolonged usage. This part was also designed to be compatible with various finger thicknesses. Using the proposed hand exoskeleton system, finger independence, multi-finger synergy, and finger joint stiffness were determined in five healthy subjects. The finger movement and force data collected in the experiments were used for analyzing three hand functions based on the physical and physiological phenomena.

A pediatric robotic thumb exoskeleton for at-home rehabilitation The isolated orthosis for thumb actuation(IOTA)

Purpose–Pediatric disorders,such as cerebral palsy and stroke,can result in thumb-in-palm deformity greatly limiting hand function.This not only limits children’s ability to perform activities of daily living but also limits important motor skill development.Specifically,the isolated orthosis for thumb actuation(IOTA)is 2 degrees of freedom(DOF)thumb exoskeleton that can actuate the carpometacarpal(CMC)and metacarpophalangeal(MCP)joints through ranges of motion required for activities of daily living.The paper aims to discuss these issues.Design/methodology/approach–IOTA consists of a lightweight hand-mounted mechanism that can be secured and aligned to individual wearers.The mechanism is actuated via flexible cables that connect to a portable control box.Embedded encoders and bend sensors monitor the 2 DOF of the thumb and flexion/extension of the wrist.A linear force characterization was performed to test the mechanical efficiency of the cable-drive transmission and the output torque at the exoskeletal CMC and MCP joints was measured.Findings–Using this platform,a number of control modes can be implemented that will enable the device to be controlled by a patient to assist with opposition grasp and fine motor control.Linear force and torque studies showed a maximum efficiency of 44 percent,resulting in a torque of 2.3971.06 in.-lbf and 0.6970.31 in.-lbf at the CMC and MCP joints,respectively.Practical implications–The authors envision this at-home device augmenting the current in-clinic and at-home therapy,enabling telerehabilitation protocols.Originality/value–This paper presents the design and characterization of a novel device specifically designed for pediatric grasp telerehabilitation to facilitate improved functionality and somatosensory learning。