Efficacy of rehabilitation exoskeleton robots on post-stroke lower limb motor dysfunction:a Meta-analysis / 中国组织工程研究

OBJECTIVE:To systematically evaluate the efficacy of rehabilitation exoskeleton robots on the lower limb motor function of stroke patients using Meta-analysis and to compare the efficacy of different lower limb exoskeleton robots,so as to provide a theoretical basis for the scientific selection of suitable exoskeleton robots for patients with post-stroke lower limb motor dysfunction. METHODS:Computer searches of the Cochrane Library,PubMed,Web of Science,Embase,CNKI,VIP,and WanFang Data were conducted to collect randomized controlled clinical studies on exploring lower extremity rehabilitation exoskeleton robots to improve lower limb motor function in stroke patients published from database inception to November 2022.Two researchers conducted the literature search and screening.The quality of the included literature was evaluated using the Cochrane 5.1.0 risk of bias assessment tool and the Jadad scale.Meta-analysis was performed using RevMan 5.4 and Stata 17.0 software. RESULTS:(1)Finally 22 publications were included,involving 865 patients(n=436 in the test group and n=429 in the control group),and the Jadad score showed that all the included articles were of high quality.(2)Meta-analysis results showed that the exoskeleton robot significantly improved the Fugl-Meyer Assessment of Lower Extremity score(mean difference[MD]=2.63,95%confidence interval[CI]:1.87-3.38,P<0.05),Berg Balance Scale score(MD=3.62,95%CI:1.21-6.03,P<0.05),Timed Up and Go score(MD=-2.77,95%CI:-4.48 to-1.05,P<0.05)and step frequency score(MD=3.15,95%CI:1.57-4.72,P<0.05)in stroke patients compared with the control group.However,there was no significant improvement in the Functional Ambulation Category Scale score(MD=0.30,95%CI:-0.01 to 0.61,P>0.05)and 6-minute walk test score(MD=3.77,95%CI:-6.60 to 14.14,P>0.05).(3)Network Meta-analysis results showed that compared with the conventional rehabilitation therapy,both the level-walking exoskeleton(MD=10.23,95%CI:3.81-27.49,P<0.05)and the body-weight support exoskeleton(MD=33.66,95%CI:11.49-98.54,P<0.05)improved the Fugl-Meyer Assessment of Lower Extremity score.Compared with the conventional rehabilitation therapy,body-weight support exoskeleton significantly improved the Berg Balance Scale scores(MD=79.86,95%CI:2.34-2 725.99,P<0.05).In terms of Fugl-Meyer Assessment of Lower Extremity and Berg Balance Scale scores,the ranking results were body-weight support exoskeleton>level-walking exoskeleton>conventional rehabilitation therapy.Compared with the conventional rehabilitation therapy,level-walking exoskeleton significantly improved the Functional Ambulation Category Scale score(MD=1.38,95%CI:1.00-1.90,P<0.05)and body-weight support exoskeleton significantly improved the Timed Up and Go score(MD=0.07,95%CI:0.01-0.51,P<0.05).In terms of Functional Ambulation Category Scale and Timed Up and Go scores,the ranking results were level-walking exoskeleton>body-weight support exoskeleton>conventional rehabilitation therapy. CONCLUSION:Rehabilitation exoskeleton robots can improve balance,walking and activities of daily living in stroke patients,with body-weight support exoskeleton being more effective in improving lower limb motor function and balance and level walking exoskeleton being more effective in improving functional walking and transfer.

Exoskeleton-assisted walking rehabilitation for spinal cord injury:CiteSpace analysis of research hotspots / 中国组织工程研究

BACKGROUND:Spinal cord injury is a serious hazard.Walking dysfunction affects the patients'quality of life most.Researches on assisted-walking with exoskeleton robots on patients with spinal cord injury have become increasingly active. OBJECTIVE:To map scientific researches of exoskeleton-assisted walking after spinal cord injury using the CiteSpace software,and to discuss the state of art,cutting-edges in the past 10 years,and trends of research in this field,in hope of providing insights for future investigations and clinical applications. METHODS:Using the Web of Science core database to conduct subject term search by Boolean logical operators,the language English was selected,search strategy:TS="spinal cord injury OR SCI"AND"walk OR walking"AND"robot OR exoskeleton OR(exoskeleton-assisted walking)OR EAW".The knowledge graph software CiteSpace 6.2.R4 was used to de-emphasize the high-quality literature.The high-quality literature obtained after reweighting was subjected to visualization analysis of hotspots and international frontier trends,such as the number of publications,country/research institution cooperation,high-influence authors/literature co-citation,keyword co-occurrence/clustering/emergence,and the scientific knowledge graph was mapped. RESULTS AND CONCLUSION:(1)A total of 544 high-quality articles were included,and the number of articles and total citation frequency in this field have shown an increasing trend in the past 10 years.(2)The top 3 countries in terms of number of publications are the USA,China,and Italy,and the top 3 research institutions are the U.S.Department of Veterans Affairs,the U.S.Veterans Health Administration,and the Swiss Federal Institute of Technology Domian.(3)The authors with the highest citation frequency(167)and betweenness centrality(0.13)are Professor Esquenazi A,University of Pennsylvania,USA,showing a high influence in this field.(4)The analysis of the top 5 cited documents in terms of citation frequency and betweenness centrality shows that:the current research on walking rehabilitation for spinal cord injury patients equipped with powered exoskeleton devices focuses on the judgment of the safety of walking rehabilitation training in real-life environments such as institutions and homes,analysis of the advantages and disadvantages of walking rehabilitation training,design of individualized training programs,and the advantages and disadvantages of the application of powered exoskeleton devices in assisted walking for patients with complete loss of locomotor function in thoracic vertebrae and the segments below,the factors affecting the effectiveness of assisted walking,and the potential for application.(5)In recent years,research in this field has focused on individuals,gait,powered exoskeleton,body weight support,functional electrical stimulation,rehabilitation,assistive technology,ambulation,recovery,and so on.(6)Early research in this field was mostly applied to stroke patients,and the frontier includes weight loss support,reciprocating gait orthosis,functional electrical stimulation and other technical means.Spinal cord injury exoskeleton-assisted walking rehabilitation research has shown an upward trend in recent years,and the focus of attention to the development of adaptive control as the mechanism of the medical lower extremity exoskeleton equipment,safety enhancement,the application of the potential to tap into the cutting-edge direction of the change,the research and detection means on the joint function of the near-infrared spectroscopic imaging and other high-end technologies,focusing on the quality of life of the patient to enhance the ability of athletic training,and to improve the body's structure of the field of the future hotspots and the frontier of the research.

Ankle rehabilitation aided by a lower limb exoskeleton robot can improve walking function after a stroke / 中华物理医学与康复杂志

Objective:To observe any effect of using a lower limb exoskeleton robot during ankle rehabilitation training on the walking ability of stroke survivors.Methods:Forty-five persons with cerebral apoplexy were randomly divided into a control group, a robot group and a combination group, each of 15. In addition to routine rehabilitation training 5 days a week for 3 weeks, the robot group additionally trained for 10 minutes assisted by a lower limb exoskeleton. The combined group joined that training and additionally undertook 10 minutes of ankle rehabilitation training. Before and after the experiment all of the participants were evaluated using the Fugl-Meyer lower extremity scale (FMA-LE), the Holden functional walking scale (FAC), and for walking speed and step frequency.Results:After treatment, significant improvement was observed in the average FMA-LE score, FAC grade, walking speed and step frequency in all 3 groups. The robot group′s average FMA-LE score, walking speed and step frequency were then significantly better than those of the control group ( P<0.05). Moreover, the average FMA-LE score, step speed and step frequency of the combined group after treatment were (22.67±1.63) min, (0.65±0.05) m/s and (80.80±4.28) steps /min, respectively, significantly better than the other two groups ( P<0.05). Conclusion:Using an exoskeleton robot combined with ankle rehabilitation training can significantly improve the walking of stroke survivors.

Effects of lower limb exoskeleton robot gait training on balance function in children with spastic diplegia / 中国康复医学杂志

Objective:To investigate the effect of lower limb exoskeleton robots on balance function in children with spas-tic diplegia. Method:Twenty children with spastic diplegia who were admitted to the Department of Rehabilitation of the Children's Hospital of Zhejiang University School of Medicine from July 2022 to December 2022 were includ-ed in the treatment group.The other 20 children matched with age,gender and functional status were includ-ed in the control group.Both groups were given conventional rehabilitation training(exercise therapy,suspen-sion training,isokinetic muscle strength training),and the treatment group were received the 30-min lower limb exoskeleton robot training 5 times a week for 8 weeks.Before and after treatment,the two groups were tested with surface electromyography(sEMG)data,dynamic balance response displacement,static balance score,and Pediatric Balance Scale(PBS). Result:Before treatment,there was no statistically significant difference(P＞0.05)in sEMG values(gluteus maximus,gluteus medius,quadriceps femoris and tibialis anterior muscle),dynamic balance reaction displace-ment,static balance score,and PBS score between the two groups.There were significant improvements in the scores of these measurements(P＜0.05)in both group before and after treatment.Compared with the con-trol group,there were statistically significant differences in sEMG values(gluteus maximus P=0.021;gluteus medius P=0.016;quadriceps femoris P=0.004),dynamic balance reaction displacement(anterior P=0.014;left P=0.003;right P=0.003),static balance score(P=0.005),and PBS score(P=0.004)in the treatment group af-ter treatment. Conclusion:Lower limb exoskeleton robot gait training combined with conventional rehabilitation treatment can effectively improve the balance function of cerebral palsy children with spastic diplegia.

Assisted technology in Parkinson's disease gait: what's up? / Tecnologia assistida na marcha da doença de Parkinson: o que há de novo?

Abstract Background Gait disturbances are prevalent and debilitating symptoms, diminishing mobility and quality of life for Parkinson's disease (PD) individuals. While traditional treatments offer partial relief, there is a growing interest in alternative interventions to address this challenge. Recently, a remarkable surge in assisted technology (AT) development was witnessed to aid individuals with PD. Objective To explore the burgeoning landscape of AT interventions tailored to alleviate PD-related gait impairments and describe current research related to such aim. Methods In this review, we searched on PubMed for papers published in English (2018-2023). Additionally, the abstract of each study was read to ensure inclusion. Four researchers searched independently, including studies according to our inclusion and exclusion criteria. Results We included studies that met all inclusion criteria. We identified key trends in assistive technology of gait parameters analysis in PD. These encompass wearable sensors, gait analysis, real-time feedback and cueing techniques, virtual reality, and robotics. Conclusion This review provides a resource for guiding future research, informing clinical decisions, and fostering collaboration among researchers, clinicians, and policymakers. By delineating this rapidly evolving field's contours, it aims to inspire further innovation, ultimately improving the lives of PD patients through more effective and personalized interventions.

Resumo Antecedentes Os distúrbios da marcha são sintomas prevalentes e debilitantes, diminuindo muito a mobilidade e a qualidade de vida dos indivíduos com doença de Parkinson (DP). Embora os tratamentos tradicionais ofereçam alívio parcial, há um interesse crescente em intervenções alternativas para enfrentar esse desafio. Recentemente, um aumento notável no desenvolvimento de tecnologia assistida (TA) foi testemunhado para ajudar indivíduos com DP. Objetivo Explorar o cenário crescente de intervenções de TA adaptadas para aliviar deficiências de marcha relacionadas à DP e descrever as pesquisas atuais para esse fim. Métodos Nessa revisão, pesquisamos artigos em inglês publicados no PubMed de 2018 a 2023. Além disso, os resumos de cada trabalho foram lidos para assegurar a sua inclusão. Quatro pesquisadores buscaram independentemente os artigos de acordo com os critérios de inclusão e exclusão. Resultados Incluímos trabalhos que preencheram os critérios de inclusão. Identificamos as tendências em tecnologia assistiva na análise dos parâmetros da marcha em DP. Esses compreendem os sensores portáteis, análise da marcha, retroalimentação em tempo real e técnicas de pista, realidade virtual e robótica. Conclusão Essa revisão é um recurso para orientar pesquisas futuras, informar decisões clínicas e promover a colaboração entre pesquisadores, médicos e formuladores de políticas. Ao delinear os contornos deste campo em rápida evolução, pretende inspirar mais inovação, melhorando em última análise a vida dos pacientes com DP através de intervenções mais eficazes e personalizadas.

Research on performance optimization method of human-machine physical interaction system considering exoskeleton wearing comfort / 生物医学工程学杂志

In order to improve the wearing comfort and bearing effectiveness of the exoskeleton, based on the prototype and working mechanism analysis of a relaxation wearable system for knee exoskeleton robot, the static optimization synthesis and its method are studied. Firstly, based on the construction of the virtual prototype model of the system, a comprehensive wearable comfort evaluation index considering the factors such as stress, deformation and the proportion of stress nodes was constructed. Secondly, based on the static simulation and evaluation index of system virtual prototype, multi-objective genetic optimization and local optimization synthesis of armor layer topology were carried out. Finally, the model reconstruction simulation data confirmed that the system had good wearing comfort. Our study provides a theoretical basis for the bearing performance and prototype construction of the subsequent wearable system.

Training in a wearable exoskeleton improves the lower limb motor recovery of stroke survivors / 中华物理医学与康复杂志

Objective:To explore any differential effect of training wearing a unilateral exoskeleton on the lower-limb motor function of stroke survivors.Methods:Forty stroke survivors were randomly divided into an exoskeleton group ( n=20) and a control group ( n=20). The control group performed conventional lower extremity exercise training while the exoskeleton group received exoskeleton-assisted lower-limb physical therapy. Each participant received eighteen 40-minute training sessions over three weeks. Before and after the intervention, the walking ability, lower-limb function, balance and ability in the activities of daily living of both groups were evaluated. Integrated electromyography (iEMG) of the rectus femoris and tibialis anterior of both legs was also recorded during sit-to-stand transitions to assess the activation of the affected muscles and the symmetry of bilateral muscle activation. Results:After the three weeks, significant improvement was observed in all of the measurements in both groups, but with the exoskeleton group scoring significantly better on average in functional ambulation category grading (1.63±0.72). Both groups′ iEMGs had also improved significantly compared with before treatment, but the exoskeleton group′s average result was by that time significantly better than the control group′s average.Conclusions:A wearable exoskeleton can effectively improve the rehabilitation of walking, lower limb movement, balance and skill in the activities of daily living of persons with subacute stroke. It better activates the affected lower limb muscles and improves the symmetry of bilateral lower limb muscle activation.

Evaluation method of assistance effect of extravehicular activity glove exoskeleton under weightlessness / 中国康复理论与实践

ObjectiveTo establish a multi index fusion hand grip fatigue prediction model to evaluate the power-assisted effect of the glove exoskeleton prototype for extravehicular clothing. MethodsBP neural network algorithm was used to establish a hand fatigue prediction model. The related factors of hand fatigue were determined with isometric grasping fatigue experiment, and the input variables of BP neural network were determined as cylinder diameter, grasping force, grasping duration and root mean square of electromyography. The fatigue data corresponding to variables of each group were obtained through experiments and subjective fatigue measurement scales, and a fatigue evaluation model based on multi-source fusion of BP neural network algorithm was established. The relationship model between fatigue and assistance effect was established, and the assistance effect of the exoskeleton prototype was evaluated through the degree of fatigue relief. ResultsThe correlation coefficient was 0.974 between the predicted results of the model and the target value. Moreover, it effectively predicted the assistance effect of different prototypes. ConclusionThe BP neural network model established by combining the grasping strength, grasping object parameters and human electromyography can predict hand fatigue, which can be used to evaluate the assistance effect of glove exoskeleton and other hand aids.

A Review on Ergonomics Factors Determining Working in Harmony with Exoskeletons

@#Exoskeletons are wearable devices that can enhance human strength and are used in various fields, such as healthcare and the manufacturing industry. However, poorly designed exoskeletons can strain the muscles and cause injuries to users. The objectives of this review paper are to review the ergonomics factors that contribute to a harmonious user-exoskeleton interaction and to explore the current trends, challenges, and future directions for developing ergonomically designed exoskeletons. In this review, 102 relevant papers published from 2015 to 2023 were retrieved from Web of Science, Scopus, and Google Scholar. These papers were considered in the analysis for gathering relevant information on the topic. The authors identified six ergonomics factors, namely kinematic compatibility, contact pressure, postural control, metabolic cost, cognitive workload, as well as task demands and workplace conditions, that can influence the interaction between users and exoskeletons. By understanding and addressing these ergonomics factors during the design and development process, exoskeleton designers can enhance the user experience and adoption of the devices in daily living activities and industrial applications.

Development and Application of Lower Limb Exoskeleton Rehabilitation Robot / 中山大学学报(医学科学版)

With the deepening of the aging of society， there are more and more patients with motor dysfunction of lower limb，and rehabilitation therapy for these patients is becoming more and more important. Since the 1980s， exoskeleton robots for lower-limb rehabilitation have been applied to the rehabilitation for patient with dyskinesia， especially those with dyskinesia caused by neurological diseases such as stroke. These exoskeleton robots are wearable， nonlinear and complex mechanical devices， which deserve to be studied and widely applied. In this review， the research status， clinical application and challenges of exoskeleton robots for lower-limb rehabilitation are described in three aspects according to the difference of the therapeutic sites of exoskeleton rehabilitation robots， and on the basis， the development trend of exoskeleton robots for lower-limb rehabilitation is prospected.

Human muscle fatigue monitoring method and its application for exoskeleton interactive control / 生物医学工程学杂志

Aiming at the human-computer interaction problem during the movement of the rehabilitation exoskeleton robot, this paper proposes an adaptive human-computer interaction control method based on real-time monitoring of human muscle state. Considering the efficiency of patient health monitoring and rehabilitation training, a new fatigue assessment algorithm was proposed. The method fully combined the human neuromuscular model, and used the relationship between the model parameter changes and the muscle state to achieve the classification of muscle fatigue state on the premise of ensuring the accuracy of the fatigue trend. In order to ensure the safety of human-computer interaction, a variable impedance control algorithm with this algorithm as the supervision link was proposed. On the basis of not adding redundant sensors, the evaluation algorithm was used as the perceptual decision-making link of the control system to monitor the muscle state in real time and carry out the robot control of fault-tolerant mechanism decision-making, so as to achieve the purpose of improving wearing comfort and improving the efficiency of rehabilitation training. Experiments show that the proposed human-computer interaction control method is effective and universal, and has broad application prospects.

Design and analysis of shoulder type exoskeleton stretcher for individual soldier / 生物医学工程学杂志

For the transportation process of rescuing wounded personnel on naval vessels, a new type of shoulder type exoskeleton stretcher for individual soldier was designed in this paper. The three-dimensional model of the shoulder type exoskeleton stretcher for individual soldier was constructed using three dimensional modeling software. Finite element analysis technique was employed to conduct statics simulation, modal analysis, and transient dynamics analysis on the designed exoskeleton stretcher. The results show that the maximum stress of the exoskeleton stretcher for walking on flat ground is 265.55 MPa, which is lower than the allowable strength of the fabrication material. Furthermore, the overall deformation of the structure is small. Modal analysis reveals that the natural frequency range of the exoskeleton stretcher under different gait conditions is 1.96 Hz to 28.70 Hz, which differs significantly from the swing frequency of 1 Hz during walking. This indicates that the designed structure can effectively avoid resonance. The transient dynamics analysis results show that the maximum deformation and stress of exoskeleton stretcher remain within the safety range, which meets the expected performance requirements. In summary, the shoulder type exoskeleton stretcher for individual soldier designed in this study can solve the problem of requiring more than 2 people to carry for the existing stretcher, especially suitable for narrow spaces of naval vessels. The research results of this paper can provide a new solution for the rescue of wounded personnel on naval vessels.

Structure Design of Hip Joint Parallel Rehabilitation Exoskeleton / 中国医疗器械杂志

At present, most of the research on hip exoskeleton robots adopts the method of decoupling analysis of hip joint motion, decoupling the ball pair motion of hip joint into rotational motion on sagittal plane, coronal plane and cross section, and designing it into series mechanism. Aiming at the problems of error accumulation and man-machine coupling in series mechanism, a parallel hip rehabilitation exoskeleton structure is proposed based on the bionic analysis of human hip joint. The structure model is established and the kinematics analysis is carried out. Through the OpenSim software, the curve of hip flexion and extension, adduction and abduction angle in a gait cycle is obtained. The inverse solution of the structure is obtained by the D-H coordinate system method. The gait data points are selected and compared with the inverse solution obtained by ADAMS software simulation. The results show that the inverse solution expression is correct. The parallel hip exoskeleton structure can meet the requirements of the rotation angle of the hip joint of the human body, and can basically achieve the movement of the hip joint, which is helpful to improve the human-computer interaction performance of the exoskeleton.

Comparison of effects of proprioceptive neuromuscular facilitation technique and lower limb robotics on lower limb motor function and automatic balance function in post-stroke patients / 中国康复医学杂志

Objective:To investigate the characteristics and differences in clinical efficacy of proprioceptive neuromuscular facilitation(PNF)and lower limb robotics in improving lower limb motor function,walking speed,and auto-matic balance function in stroke patients. Method:Seventy-two stroke patients with hemiplegia who met the criteria were randomly assigned to the con-ventional group(n=25),PNF group(n=24),and lower limb robotics group(n=23).The treatment lasted for 4 weeks.Before and after treatment,the Fugl-Meyer assessment lower extremity scale(FMA-LE),10m maxi-mum walking speed test(MWS),and neuro com balance manager system were used to evaluate lower limb movement function,walking speed and automatic balance function. Result:After 4 weeks of treatment,the FMA-LE score of PNF group was significantly better than that of conventional group(P＜0.05)and lower limb robotics group(P-0.001),the MWS score in the lower limb ro-botics group was significantly better than that in the conventional group(P＜0.05)and the PNF group(P=0.001),and the MWS score in the PNF group was significantly better than that in the conventional group(P＜0.05).The lower limb robotics group showed significantly better scores in the reaction time,movement veloci-ty,endpoint travel distance,maximum excursions and directional control index score than the conventional group(P＜0.05)and the PNF group(P＜0.05),while the directional control index score in the PNF group was significantly better than that in the conventional group(P=0.049). Conclusion:Manual PNF therapy and lower limb robotics training have their own clinical efficacy in stroke patients,with PNF technique being more effective in improving lower limb motor function,while lower limb robotics have an advantage in automatic balance function and walking speed.

Mechanical Design and Research of Wearable Exoskeleton Assisted Robot for Upper Limb Rehabilitation / 中国医疗器械杂志

Based on the biomechanical mechanism of human upper limb, the disadvantages of traditional rehabilitation training and the current status of upper limb rehabilitation robot, a six degree of freedom, flexible adjustment, wearable upper limb rehabilitation exoskeleton design scheme is proposed. Firstly, the mechanics of each joint of the upper limb is analyzed, and the virtual prototype design of the whole mechanical structure of the upper limb rehabilitation wearable exoskeleton is carried out by using CATIA three-dimensional software. The tooth transmission of the forearm and the upper arm single row four point contact ball bearing with internal/external rotation and the shoulder flexible passive adjustment mechanism (viscoelastic damper) are innovatively designed. Then, the joints of the upper limb rehabilitation exoskeleton are analyzed, theoretical analysis and calculation of the driving torque, the selection of the motor and gearbox of each driving joint are carried out. Finally, the whole finite element analysis of the upper limb exoskeleton is carried out. The research and experimental results showed that the design scheme of the upper limb exoskeleton assist structure is highly feasible, which can help the patients with upper limb paralysis and motor dysfunction self-rehabilitation.

Effects of ankle exoskeleton assistance during human walking on lower limb muscle contractions and coordination patterns / 生物医学工程学杂志

Lower limb ankle exoskeletons have been used to improve walking efficiency and assist the elderly and patients with motor dysfunction in daily activities or rehabilitation training, while the assistance patterns may influence the wearer's lower limb muscle activities and coordination patterns. In this paper, we aim to evaluate the effects of different ankle exoskeleton assistance patterns on wearer's lower limb muscle activities and coordination patterns. A tethered ankle exoskeleton with nine assistance patterns that combined with differenet actuation timing values and torque magnitude levels was used to assist human walking. Lower limb muscle surface electromyography signals were collected from 7 participants walking on a treadmill at a speed of 1.25 m/s. Results showed that the soleus muscle activities were significantly reduced during assisted walking. In one assistance pattern with peak time in 49% of stride and peak torque at 0.7 N·m/kg, the soleus muscle activity was decreased by (38.5 ± 10.8)%. Compared with actuation timing, the assistance torque magnitude had a more significant influence on soleus muscle activity. In all assistance patterns, the eight lower limb muscle activities could be decomposed to five basic muscle synergies. The muscle synergies changed little under assistance with appropriate actuation timing and torque magnitude. Besides, co-contraction indexs of soleus and tibialis anterior, rectus femoris and semitendinosus under exoskeleton assistance were higher than normal walking. Our results are expected to help to understand how healthy wearers adjust their neuromuscular control mechanisms to adapt to different exoskeleton assistance patterns, and provide reference to select appropriate assistance to improve walking efficiency.

A pace recognition method for exoskeleton wearers based on support vector machine-hidden Markov model / 生物医学工程学杂志

In order to improve the motion fluency and coordination of lower extremity exoskeleton robots and wearers, a pace recognition method of exoskeleton wearer is proposed base on inertial sensors. Firstly, the triaxial acceleration and triaxial angular velocity signals at the thigh and calf were collected by inertial sensors. Then the signal segment of 0.5 seconds before the current time was extracted by the time window method. And the Fourier transform coefficients in the frequency domain signal were used as eigenvalues. Then the support vector machine (SVM) and hidden Markov model (HMM) were combined as a classification model, which was trained and tested for pace recognition. Finally, the pace change rule and the human-machine interaction force were combined in this model and the current pace was predicted by the model. The experimental results showed that the pace intention of the lower extremity exoskeleton wearer could be effectively identified by the method proposed in this article. And the recognition rate of the seven pace patterns could reach 92.14%. It provides a new way for the smooth control of the exoskeleton.

Characteristic Analysis on Human-Machine Interaction Force of Lower Limb Exoskeleton / 医用生物力学

Objective To propose a human-machine coupling dynamics modeling method based on virtual muscles, so as to quantitatively analyze the characteristics of human-computer interaction force and muscle activation of the musculoskeletal system. Methods First, in the gait experiment of wearing exoskeleton, the human motion capture system and self-developed mechanical monitoring device were used to obtain the wearer’s walking dynamics, electromyography (EMG) signals, exoskeleton drive status and local human-computer interaction information. The human-machine coupling model was established in modeling environment of the bone system, and the gait experiment data and the exoskeleton joint torques were used as driving information of the coupling model to perform inverse mechanical calculations. Finally, by adjusting strength and stiffness parameters of the virtual muscles, the real data of the model was compared with the experimental test result, to quantitatively evaluate effectiveness of the human-machine coupling model of the lower extremity exoskeleton. Results The normal interaction force calculated by inverse dynamics of the coupled model and the activation of lower limb muscles had a good consistency in response curve trend compared with measurement results of the gait experiment, and the interaction force results had a high degree of correlation (r=0.931, P<0.01), the root mean square error was small, and the peak error of lower limb muscle activation was lower than 5%. Conclusions The human-machine coupling model proposed in this study can effectively calculate the interaction force between human and exoskeleton. The establishment of the coupling model provides a theoretical basis for verification and iteration of the exoskeleton structure optimization and control algorithm, as well as performance evaluation on mobility assistance effects of the exoskeleton.

Comparison between Thin-Layer Models and Non-Traditional Methods in the Modelling of Drying Kinetics of Crustacean Wastes

Abstract This research aims to compare the classical thin-layer models, stepwise fit regression method (SRG) and artificial neural networks (ANN) in the modelling of drying kinetics of shrimp shell and crab exoskeleton. Thus, drying curves were obtained using a convective dryer (3.0 m/s) at temperatures of 30.45 and 60oC. The results showed a decreasing tendency for the drying time as the temperature increased for both materials. Drying curves modelling of both materials showed fitted results with R 2 adj >0.998 and MRE<13.128% for some thin-layer models. On the other hand, by SRG a simple model could be obtained as a function of time and temperature, with the greatest accuracy being found in the modelling of experimental data of crab exoskeleton, with MRE<10.149%. Finally, the ANNs were employed successfully in the modelling of drying kinetics, showing high prediction quality with the trained recurrent ANN models.

Rehabilitación temprana de fracturas de radio distal con ortesis robóticas. Reporte de Casos / Early rehabilitation of distal radius fractures with robotic orthosis. Case Report

Introducción Los exoesqueletos robóticos son una nueva alternativa para complementar los procesos de rehabilitación funcional de la muñeca, facilitando la terapia de movilización pasiva temprana posterior a eventos traumáticos locales, con el propósito de mantener o restaurar el arco articular mientras cicatrizan los tejidos o consolidan las fracturas. El objetivo del estudio es presentar los resultados de la terapia de movilización temprana de forma pasiva mediante ortesis robóticas de muñeca. Materiales y Métodos Se seleccionaron cuatro pacientes con fracturas de radio distal, quienes fueron tratados quirúrgicamente con reducción abierta de la fractura más osteosíntesis con sistema de placa de bloqueo volar, fisioterapia convencional y movilización temprana con la órtesis robótica PRO-Wix; además, se hizo seguimiento clínico de la funcionalidad (escala DASH), del dolor (escala EVA), de los arcos de movilidad articular (goniómetro), de la adherencia y los potenciales eventos adversos. Resultados todos los pacientes se reintegraron a sus actividades de la vida diaria luego de tres semanas de rehabilitación, se registró recuperación del arco de movilidad articular, disminución de la intensidad del dolor, recuperación funcional, adecuada adherencia y no se presentaron eventos adversos. Discusión conservar al máximo la anatomía articular en la intervención quirúrgica especializada es la base para iniciar la rehabilitación temprana, y permitirá que el paciente tolere la movilización pasiva con órtesis robóticas.

Background Robotic exoskeletons are a new alternative to complement the functional rehabilitation processes of the wrist, facilitating early passive mobilization therapy after local traumatic events, with the purpose of maintaining or restoring joint range of motion while the tissues heal. The aim of the study is to present the results of early mobilization therapy in a passive robotic wrist orthosis. Methods Four patients with distal radius fractures were selected, treated surgically with open reduction and internal fixation of distal radius fracture with volar plate locking system. Conventional physiotherapy and early mobilization with the PRO-Wix robotic orthosis was performed. Clinical monitoring of functionality (DASH scale), pain (VAS scale), joint mobility arches (goniometer), adherence and potential adverse events were carried out. Results all patients returned to their daily living activities after three weeks of rehabilitation. Recovery of normal wrist joint range of motion was achieved; decreased in pain intensity, functional recovery, adequate adherence to rehabilitation protocol and adverse events were also recorded. Discussion preserving the joint anatomy as much as possible in specialized surgical intervention is the basis for starting early rehabilitation, and allowing the patient to tolerate passive mobilization with robotic orthoses. Further studies including a wide number of patients have to be conducted.