Search Results (1,045)

This article has as the main subject the exoskeleton devices used in rehabilitation applications of the wrist joint for patients who are in the recovery period after suffering a stroke. Exoskeleton devices have some advantages compared to classic therapies, such as the possibility of performing rehabilitation exercises from the comfort of your own home. Therefore, in this article, a short state of the art with the main devices developed at the present time was carried out. By developing a structural analysis, it was shown that the parallel manipulator structures used for the development of the exoskeleton have 2 DoF, and they can contain RRU, RTU, or TRU connection legs. Next, the kinematic analysis of the structure with RRU connection legs is presented, from which the transmission function for the four-bar linkages was extracted. The study continues with the optimization of the synthesis in order to achieve a higher value for the minimum input transmission angle and a lower value for the total size area. Using the optimized results, a 3D prototype and the performance analysis were developed. The main conclusion of this article is that the presented 2-RRU-U parallel manipulator can be a suitable proposal for a rehabilitation exoskeleton-type device due to the optimization of the total size area and the higher value of the minimum input transmission angle. Full article

This study evaluates, for the first time, the reducing capacity, radical scavenger activity, and in vitro antitumor and anti-inflammatory effects of chitosan, astaxanthin, and bio-phenols extracted from the exoskeleton of Sicilian Procambarus clarkii, the most widespread species of invasive crayfish in the Mediterranean region. Among the extracted compounds, astaxanthin exhibited the highest antioxidant activity in all assays. Chitosan and polyphenols demonstrated reducing and radical scavenging activity; chitosan showed significant ferric ion reducing capacity in the FRAP test, while bio-phenolic compounds displayed notable radical scavenging activity in the DPPH and ABTS assays. Both astaxanthin and polyphenols showed dose-dependent cytotoxicity on two different cancer cell lines, with IC50 values of 1.45 µg/mL (phenolic extract) and 4.28 µg/mL (astaxanthin extract) for HepG2 cells and 2.45 µg/mL (phenolic extract) and 4.57 µg/mL (astaxanthin extract) for CaCo-2 cells. The bio-phenolic extract also showed potential anti-inflammatory effects in vitro by inhibiting nitric oxide production in inflamed RAW 264.7 macrophages, reducing the treated/control NO ratio to 77% and 74% at concentrations of 1.25 and 1.5 μg/mL, respectively. These results suggest that P. clarkii exoskeletons could be a valuable source of bioactive molecules for biomedical, pharmaceutical, and nutraceutical application while contributing to the sustainable management of this invasive species. Full article

This review provides a comprehensive analysis of studies investigating the impact of occupational exoskeletons on work-related musculoskeletal disorder (WMSD) risk factors. The primary objective is to examine the methodologies used to assess the effectiveness of these devices across various occupational tasks. A systematic review was conducted following the PRISMA guidelines, covering studies published between 2014 and 2024. A total of 49 studies were included, identified through searches conducted in Scopus and Web of Science databases, with the search string launched in August 2024. The review identifies a growing body of research on passive and active exoskeletons, with a notable focus on laboratory-based evaluations. The results indicate that direct measurement and self-report methods are the preferred approaches in these domains. Ergonomic limitations and user discomfort remain concerns in some cases. The findings of this review may influence stakeholders by providing insights into the potential benefits of adopting exoskeletons and improving workplace ergonomics to reduce WMSD risks. Additionally, the identification of WMSD assessment methods will be valuable for validating the use of these technologies in the workplace. The review concludes with recommendations for future research, emphasizing the need for more real-world assessments and improved exoskeleton designs to enhance user comfort and efficacy. Full article

Advancements in science and technology have driven the growing use of robots in daily life, with Portable-Powered Lower Limb Exoskeletons (PPLLEs) emerging as a key innovation. The selection of mechanisms, control strategies, and sensors directly influences the overall performance of the exoskeletons, making it a crucial consideration for research and development. This review examines the current state of PPLLE research, focusing on the aspects of mechanisms, control strategies, and sensors. We discuss the current research status of various technologies, their technological compatibility, and respective benefits comprehensively. Key findings highlight effective designs and strategies, as well as future challenges and opportunities. Finally, we summarize the overall status of PPLLE research and attempt to shed light on the future potential directions of research and development. Full article

In this study, a fuzzy adaptive impedance control method integrating the backstepping control for the PAM elbow exoskeleton was developed to facilitate robot-assisted rehabilitation tasks. The proposed method uses fuzzy logic to adjust impedance parameters, thereby optimizing user adaptability and reducing interactive torque, which are major limitations of traditional impedance control methods. Furthermore, a repetitive learning algorithm and an adaptive control strategy were incorporated to improve the performance of position accuracy, addressing the time-varying uncertainties and nonlinear disturbances inherent in the exoskeleton. The stability of the proposed controller was tested, and then corresponding simulations and an elbow flexion and extension rehabilitation experiment were performed. The results showed that, with the proposed method, the root mean square of the tracking error was 0.032 rad (i.e., 21.95% less than that of the PID method), and the steady-state interactive torque was 1.917 N·m (i.e., 46.49% less than that of the traditional impedance control). These values exceeded those of the existing methods and supported the potential application of the proposed method for other soft actuators and robots. Full article

In the last decades, there has been an increasing number of human patients who suffer from upper-limb disorders limiting their motor abilities. One of the possible solutions that gained extensive research interest is the development of robot-aided rehabilitation training setups, including either end-effector or exoskeleton robots, which showed various advantages compared to traditional manual rehabilitation therapy. One of the main challenges of these systems is to control the robot’s motion to track a desirable rehabilitation training trajectory while being affected by either voluntary or involuntary human forces depending on the patient’s recovery state. Several previous studies have been targeting exoskeleton robotic systems focusing on their structure, clinical features, and control methods, with limited review on end-effector-based robotic rehabilitation systems. In this regard, an overview of the most common end-effector robotic devices used for upper-limb rehabilitation is provided in this paper, describing their mechanical structure, features, clinical application, commercialization, advantages, and shortcomings. Additionally, a comprehensive review on possible control methods applied to end-effector rehabilitation exploitation is presented. These control methods are categorized as conventional, robust, intelligent, and most importantly, adaptive controllers implemented to serve for diverse rehabilitation control modes, addressing their development, implementation, findings, and possible drawbacks. Full article

The increasing demand for rehabilitation and walking assistive devices driven by aging populations has promoted the development of a novel hip joint structure. This design aims to enhance the functionality of lower limb exoskeletons by eliminating the kinematic mismatch with the human’s biological hip. The design utilizes three 1-DOF (Degree of Freedom) rotational joints to replicate natural hip movement. By integrating IMU data, motor compensation is dynamically made to facilitate a more natural gait. Experimental results indicate improved hip joint angles and enhanced user comfort, presenting a promising solution for better walking assistance for elderly individuals. Full article

Maize productivity has remained low and has worsened in the wake of a changing climate, resulting in new invasive pests, with pests that were earlier designated as minor becoming major and with pathogens being transported by pests and/or entering their feeding sites. A study was conducted in 2021 in the Kisumu and Makueni counties, Kenya, to determine how different maize cropping systems affect insect diversity, insect damage to maize, and insects’ ability to spread mycotoxigenic fungi in pre-harvest maize. The field experiments used a randomized complete block design, with the four treatments being maize monocrop, maize intercropped with beans, maize–bean intercrop with the addition of Trichoderma harzianum at planting, and push–pull technology. The FAW, Spodoptera frugiperda (J.E Smith) (Lepidoptera: Noctuidae), was the most damaging pest in the two regions. The push–pull and the maize–bean intercropping technologies significantly reduced the maize foliage and ear damage caused by the FAW. Beetles passively spread mycotoxigenic Aspergillus spp. and Fusarium verticillioides on pre-harvest maize. Maize weevils, namely, Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae), and Carpophilus dimidiatus Fabricius, 1792 (Coleoptera: Nitidulidae), earwigs, namely, Forficula spp. L. (Dermaptera: Forficulidae), and carpenter ants, namely, Camponotus spp. L. (Hymenoptera: Formicidae) carried the highest number of spores on their exoskeletons. This study stresses the role of insects in the spread of fungi on pre-harvest maize and their possible control by intercropping and other cropping technologies. Full article

In recent years, the increasing number of patients with spinal cord injuries, strokes, and lower limb disabilities has led to the gradual development of rehabilitation-assisted exoskeleton robots. A critical aspect of these robots is their ability to accurately sense human movement intentions to achieve smooth and natural control. This paper describes research carried out on predicting the motion angles of human lower limb joints. Based on the design of a signal acquisition system for physiological muscle signals and inertial measurement unit (IMU) data, a hybrid neural network prediction model (QRTCN-BiLSTM) and a single neural network prediction model (QRBiLSTM) were constructed using quantile regression, temporal convolution network (TCN) and bidirectional long short-term memory network (BiLSTM), respectively. At the same time, 7-channel surface electromyographic signals (sEMG) and 12-channel IMU data from hip and knee joints were collected and input into the QRBiLSTM and QRTCN-BiLSTM models to unfold the training and analyze the comparison. The results show that the QRTCN-BiLSTM model can more accurately infer human movement intention and provide a more reliable and accurate prediction tool for human–robot interaction research in rehabilitation robotics. Full article

Soft exoskeletons (exosuits) are expected to provide a comfortable wearing experience and compliant assistance compared with traditional rigid exoskeleton robots. In this paper, an exosuit with twisted string actuators (TSAs) is developed to provide high-strength and variable-stiffness actuation for hemiplegic patients. By formulating the analytic model of the TSA and decoding the human impedance characteristic, the human-exosuit coupled dynamic model is constructed. An adaptive impedance controller is designed to transfer the skills of the patient’s healthy limb (HL) to the bilateral impaired limb (IL) with a mirror training strategy, including the movement trajectory and stiffness profiles. A reinforcement learning (RL) algorithm is proposed to optimize the robotic assistance by adapting the impedance model parameters to the subject’s performance. Experiments are conducted to demonstrate the effectiveness and superiority of the proposed method. Full article

Prolonged awkward arm postures and repetitive tasks in industrial environments can easily lead to worker injuries. The occupational shoulder exoskeleton is a promising solution to reducing the incidence of work-related musculoskeletal disorders, especially in the shoulder. In general, the device has to be compatible with the human shoulder, which is one of the most complex joints, thus posing significant challenges in existing efforts to design occupational shoulder exoskeletons. The purpose of this paper is to present a comprehensive review of exoskeletons designed to support human shoulders and arms in industrial applications. Recent developments and advancements in mechanism design, actuators, and control aspects are discussed in detail. A brief overview of the evaluation (i.e., participants, task design, objective, and subjective assessment) is also reported, and the experiment protocol to assess performance is summarized. Finally, existing challenges and possible future research directions for occupational shoulder exoskeletons are provided. Full article

The assessment of realistic work tasks is a critical aspect of introducing exoskeletons to work environments. However, as the experimental task’s complexity increases, the analysis of muscle activity becomes increasingly challenging. Thus, it is essential to use metrics that adequately represent the physical human–exoskeleton interaction (pHEI). Muscle activity analysis is usually reduced to a comparison of point values (average or maximum muscle contraction), neglecting the signals’ trend. Metrics based on single values, however, lack information about the dynamism of the task and its duration. Their meaning can be uncertain, especially when analyzing complex movements or temporally extended activities, and it is reduced to an overall assessment of the interaction on the whole task. This work proposes a method based on integrated EMGs (iEMGs) to evaluate the pHEI by considering task dynamism, temporal duration, and the neural energy associated with muscle activity. The resulting signal highlights the task phases in which the exoskeleton reduces or increases the effort required to accomplish the task, allowing the calculation of specific indices that quantify the energy exchange in terms of assistance (AII), resistance (RII), and overall interaction (OII). The method provides an analysis tool that enables developers and controller designers to receive insights into the exoskeleton performances and the quality of the user-robot interaction. The application of this method is provided for passive and two active back support exoskeletons: the Laevo, XoTrunk, and StreamEXO. Full article

Recent advancements in patient rehabilitation integrate both traditional and modern techniques to enhance treatment efficacy and accessibility. Hydrotherapy, leveraging water’s physical properties, is crucial for reducing joint stress, alleviating pain, and improving circulation. The rehabilitation of upper limbs benefits from technologies like virtual reality and robotics which, when combined with hydrotherapy, can accelerate recovery. Exoskeletons, which support and enhance movement, have shown promise for patients with neurological conditions or injuries. This study focused on implementing and comparing proportional–integral–derivative (PID) and fuzzy logic controllers (FLCs) in a lower limb exoskeleton. Initial PID control tests revealed instability, leading to a switch to a PI controller for better stability and the development of a fuzzy control system. A hybrid strategy was then applied, using FLC for smooth initial movements and PID for precise tracking, with optimized weighting to improve performance. The combination of PID and fuzzy controllers, with tailored weighting (70% for moderate angles and 100% for extensive movements), enhanced the exoskeleton’s stability and precision. This study also explored quantum computing techniques, such as the quantum approximate optimization algorithm (QAOA) and the quantum Fourier transform (QFT), to optimize controller tuning and improve real-time control, highlighting the potential of these advanced tools in refining rehabilitation devices. Full article

This study uses Artificial Neural Networks (ANNs) and multiple linear regression (MLR) models to explore the relationship between gait dynamics and the metabolic cost. Six nonlinear metrics—Lyapunov Exponents based on Rosenstein’s algorithm (LyER), Detrended Fluctuation Analysis (DFA), the Approximate Entropy (ApEn), the correlation dimension (CD), the Sample Entropy (SpEn), and Lyapunov Exponents based on Wolf’s algorithm (LyEW)—were utilized to predict the metabolic cost during walking. Time series data from 10 subjects walking under 13 conditions, with and without hip exoskeletons, were analyzed. Six ANN models, each corresponding to a nonlinear metric, were trained using the Levenberg–Marquardt backpropagation algorithm and compared with MLR models. Performance was assessed based on the mean squared error (MSE) and correlation coefficients. ANN models outperformed MLR, with DFA and Lyapunov Exponent models showing higher R² values, indicating stronger predictive accuracy. The results suggest that gait’s nonlinear characteristics significantly impact the metabolic cost, and ANNs are more effective for analyzing these dynamics than MLR models. The study emphasizes the potential of focusing on specific nonlinear gait variables to enhance assistive device optimization, particularly for hip exoskeletons. These findings support the development of personalized interventions that improve walking efficiency and reduce metabolic demands, offering insights into the design of advanced assistive technologies. Full article

Background: Guillain–Barré syndrome (GBS) is an immune-mediated polyradiculoneuropathy that represents a leading cause of motor impairment. Robot-assisted therapy (RAT) has been widely applied in various neurological conditions. However, the use of RAT in GBS remains underexplored. This systematic review (SR) aims to evaluate the preliminary evidence regarding the efficacy of RAT in terms of motor recovery in people with GBS (pwGBSs). Secondly, the study protocol for a randomized RCT is reported. Methods: A comprehensive SR was conducted on PubMed, Scopus, EMBASE, Cochrane Library, and Epistemikos. Risk of bias was assessed using the National Institute of Health (NIH) study quality assessment. The SR’s protocol was recorded in the PROSPERO database. Results: Out of 116 articles found, four studies published in the past four years met the inclusion criteria. These studies investigated the effects of RAT on lower limbs (three studies) and upper limbs (one study) in four pwGBSs. The results showed improvements in motor function and patient engagement, but it is impossible to generalize the findings. Conclusions: Our SRs supports the rationale for an RCT to assess the efficacy of RAT in pwGBSs. We present the protocol for a double-blind RCT to evaluate the effects of RAT on upper limb motor function in pwGBSs. Full article