A new modular neuroprosthesis suitable for hybrid FES-robot applications and tailored assistance.

BACKGROUND: To overcome the application limitations of functional electrical stimulation (FES), such as fatigue or nonlinear muscle response, the combination of neuroprosthetic systems with robotic devices has been evaluated, resulting in hybrid systems that have promising potential. However, current technology shows a lack of flexibility to adapt to the needs of any application, context or individual. The main objective of this study is the development of a new modular neuroprosthetic system suitable for hybrid FES-robot applications to meet these needs. METHODS: In this study, we conducted an analysis of the requirements for developing hybrid FES-robot systems and reviewed existing literature on similar systems. Building upon these insights, we developed a novel modular neuroprosthetic system tailored for hybrid applications. The system was specifically adapted for gait assistance, and a technological personalization process based on clinical criteria was devised. This process was used to generate different system configurations adjusted to four individuals with spinal cord injury or stroke. The effect of each system configuration on gait kinematic metrics was analyzed by using repeated measures ANOVA or Friedman's test. RESULTS: A modular NP system has been developed that is distinguished by its flexibility, scalability and personalization capabilities. With excellent connection characteristics, it can be effectively integrated with robotic devices. Its 3D design facilitates fitting both as a stand-alone system and in combination with other robotic devices. In addition, it meets rigorous requirements for safe use by incorporating appropriate safety protocols, and features appropriate battery autonomy, weight and dimensions. Different technological configurations adapted to the needs of each patient were obtained, which demonstrated an impact on the kinematic gait pattern comparable to that of other devices reported in the literature. CONCLUSIONS: The system met the identified technical requirements, showcasing advancements compared to systems reported in the literature. In addition, it demonstrated its versatility and capacity to be combined with robotic devices forming hybrids, adapting well to the gait application. Moreover, the personalization procedure proved to be useful in obtaining various system configurations tailored to the diverse needs of individuals.

[A review of functional electrical stimulation based on brain-computer interface].

Individuals with motor dysfunction caused by damage to the central nervous system are unable to transmit voluntary movement commands to their muscles, resulting in a reduced ability to control their limbs. However, traditional rehabilitation methods have problems such as long treatment cycles and high labor costs. Functional electrical stimulation (FES) based on brain-computer interface (BCI) connects the patient's intentions with muscle contraction, and helps to promote the reconstruction of nerve function by recognizing nerve signals and stimulating the moving muscle group with electrical impulses to produce muscle convulsions or limb movements. It is an effective treatment for sequelae of neurological diseases such as stroke and spinal cord injury. This article reviewed the current research status of BCI-based FES from three aspects: BCI paradigms, FES parameters and rehabilitation efficacy, and looked forward to the future development trend of this technology, in order to improve the understanding of BCI-based FES.

Hebbian plasticity induced by temporally coincident BCI enhances post-stroke motor recovery.

Functional electrical stimulation (FES) can support functional restoration of a paretic limb post-stroke. Hebbian plasticity depends on temporally coinciding pre- and post-synaptic activity. A tight temporal relationship between motor cortical (MC) activity associated with attempted movement and FES-generated visuo-proprioceptive feedback is hypothesized to enhance motor recovery. Using a brain-computer interface (BCI) to classify MC spectral power in electroencephalographic (EEG) signals to trigger FES-delivery with detection of movement attempts improved motor outcomes in chronic stroke patients. We hypothesized that heightened neural plasticity earlier post-stroke would further enhance corticomuscular functional connectivity and motor recovery. We compared subcortical non-dominant hemisphere stroke patients in BCI-FES and Random-FES (FES temporally independent of MC movement attempt detection) groups. The primary outcome measure was the Fugl-Meyer Assessment, Upper Extremity (FMA-UE). We recorded high-density EEG and transcranial magnetic stimulation-induced motor evoked potentials before and after treatment. The BCI group showed greater: FMA-UE improvement; motor evoked potential amplitude; beta oscillatory power and long-range temporal correlation reduction over contralateral MC; and corticomuscular coherence with contralateral MC. These changes are consistent with enhanced post-stroke motor improvement when movement is synchronized with MC activity reflecting attempted movement.

Feasibility of Telerehabilitation-Monitored Functional Electrical Stimulation on Walking and Quality of Life in People With Multiple Sclerosis: A Case Series.

BACKGROUND: Foot drop in people with multiple sclerosis (MS) commonly leads to decreased mobility and quality of life (QOL). Functional electrical stimulation (FES) of the peroneal nerve can improve the gait of people with foot drop, yet various barriers restrict widespread use. The purpose of this case series was to examine the feasibility of a telerehabilitation-monitored FES device and report changes in functional mobility and QOL in people with moderate MS-related disability. METHODS: FES use was progressed over 8 weeks via 3 telerehabilitation sessions. Feasibility of telerehabilitation was assessed by percentage of telerehabilitation visits completed and participant-reported satisfaction. At baseline and study completion, functional mobility with and without FES were assessed by the Timed 25-Foot Walk (T25FW), Timed Up and Go (TUG), and 2-Minute Walk Test (2MWT), Multiple Sclerosis Impact Scale (MSIS-29), and the 12-item Multiple Sclerosis Walking Scale (MSWS-12). Fatigue was assessed via the Modified Fatigue Impact Scale (MFIS) before and after the intervention. RESULTS: Eleven participants (mean age = 50.4 years [SD 10.8]; 2 males) completed the study. All (33/33) telerehabilitation visits were completed and participants attained high levels of satisfaction with no adverse events. At 8 weeks, compared to baseline, there were clinically meaningful improvements on the T25FW, 2MWT, and TUG for 45%, 55%, and 82% of participants, respectively. Clinically meaningful improvements on the MSIS-29 and MSWS-12 were also recorded for 64% and 36% of participants, respectively. CONCLUSIONS: Telerehabilitation was safe and feasible for FES intervention, and improvements in functional mobility and QOL were observed. Telerehabilitation to monitor FES may improve access and reduce patient burden; therefore, studying its efficacy is warranted.

Ultrasound-Compatible Electrode for Functional Electrical Stimulation.

Functional electrical stimulation (FES) is a vital method in neurorehabilitation used to reanimate paralyzed muscles, enhance the size and strength of atrophied muscles, and reduce spasticity. FES often leads to increased muscle fatigue, necessitating careful monitoring of the patient's response. Ultrasound (US) imaging has been utilized to provide valuable insights into FES-induced fatigue by assessing changes in muscle thickness, stiffness, and strain. Current commercial FES electrodes lack sufficient US transparency, hindering the observation of muscle activity beneath the skin where the electrodes are placed. US-compatible electrodes are essential for accurate imaging and optimal FES performance, especially given the spatial constraints of conventional US probes and the need to monitor muscle areas directly beneath the electrodes. This study introduces specially designed body-conforming US-compatible FES (US-FES) electrodes constructed with a silver nanowire/polydimethylsiloxane (AgNW/PDMS) composite. We compared the performance of our body-conforming US-FES electrode with a commercial hydrogel electrode. The findings revealed that our US-FES electrode exhibited comparable conductivity and performance to the commercial one. Furthermore, US compatibility was investigated through phantom and in vivo tests, showing significant compatibility even during FES, unlike the commercial electrode. The results indicated that US-FES electrodes hold significant promise for the real-time monitoring of muscle activity during FES in clinical rehabilitative applications.

Sensing and Control Strategies Used in FES Systems Aimed at Assistance and Rehabilitation of Foot Drop: A Systematic Literature Review.

Functional electrical stimulation (FES) is a rehabilitation and assistive technique used for stroke survivors. FES systems mainly consist of sensors, a control algorithm, and a stimulation unit. However, there is a critical need to reassess sensing and control techniques in FES systems to enhance their efficiency. This SLR was carried out following the PRISMA 2020 statement. Four databases (PubMed, Scopus, Web of Science, Wiley Online Library) from 2010 to 2024 were searched using terms related to sensing and control strategies in FES systems. A total of 322 articles were chosen in the first stage, while only 60 of them remained after the final filtering stage. This systematic review mainly focused on sensor techniques and control strategies to deliver FES. The most commonly used sensors reported were inertial measurement units (IMUs), 45% (27); biopotential electrodes, 36.7% (22); vision-based systems, 18.3% (11); and switches, 18.3% (11). The control strategy most reported is closed-loop; however, most of the current commercial FES systems employ open-loop strategies due to their simplicity. Three main factors were identified that should be considered when choosing a sensor for gait-oriented FES systems: wearability, accuracy, and affordability. We believe that the combination of computer vision systems with artificial intelligence-based control algorithms can contribute to the development of minimally invasive and personalized FES systems for the gait rehabilitation of patients with FDS.

A Propulsion Neuroprosthesis Improves Overground Walking in Community-Dwelling Individuals After Stroke.

Functional electrical stimulation (FES) is a common neuromotor intervention whereby electrically evoked dorsiflexor muscle contractions assist foot clearance during walking. Plantarflexor neurostimulation has recently emerged to assist and retrain gait propulsion; however, safe and effective coordination of dorsiflexor and plantarflexor neurostimulation during overground walking has been elusive, restricting propulsion neuroprostheses to harnessed treadmill walking. We present an overground propulsion neuroprosthesis that adaptively coordinates, on a step-by-step basis, neurostimulation to the dorsiflexors and plantarflexors. In 10 individuals post-stroke, we evaluate the immediate effects of plantarflexor neurostimulation delivered with different onset timings, and retention to unassisted walking (NCT06459401). Preferred onset timing differed across individuals. Individualized tuning resulted in a significant 10% increase in paretic propulsion peak (Δ: 1.41 ± 1.52%BW) and an 8% increase in paretic plantarflexor power (Δ: 0.27 ± 0.23 W/kg), compared to unassisted walking. Post-session unassisted walking speed, paretic propulsion peak, and propulsion symmetry all significantly improved by 9% (0.14 ± 0.09 m/s), 28% (2.24 ± 3.00%BW), and 12% (4.5 ± 6.0%), respectively, compared to pre-session measurements. Here we show that an overground propulsion neuroprosthesis can improve overground walking speed and propulsion symmetry in the chronic phase of stroke recovery. Future studies should include a control group to examine the efficacy of gait training augmented by the propulsion neuroprosthesis compared to gait training alone.

Combining robotics and functional electrical stimulation for assist-as-needed support of leg movements in stroke patients: A feasibility study.

PURPOSE: Rehabilitation technology can be used to provide intensive training in the early phases after stroke. The current study aims to assess the feasibility of combining robotics and functional electrical stimulation (FES), with an assist-as-needed approach to support actively-initiated leg movements in (sub-)acute stroke patients. METHOD: Nine subacute stroke patients performed repetitions of ankle dorsiflexion and/or knee extension movements, with and without assistance. The assist-as-needed algorithm determined the amount and type of support needed per repetition. The number of repetitions and range of motion with and without assistance were compared with descriptive statistics. Fatigue scores were obtained using the visual analogue scale (score 0-10). RESULTS: Support was required in 44 % of the repetitions for ankle dorsiflexion and in 5 % of the repetitions of knee extension, The median fatigue score was 2.0 (IQR: 0.2) and 4.0 (IQR: 1.5) for knee and ankle, respectively, indicating mild to moderate perceived fatigue. CONCLUSION: This study demonstrated the feasibility of assist-as-needed assistance through combined robotic and FES support of leg movements in stroke patients. It proved particularly useful for ankle dorsiflexion. Future research should focus on implementing this approach in a clinical setting, to assess clinical applicability and potential effects on leg function.

The Role of Virtual Reality and Functional Electrical Stimulation on a Seven-Year-Old Child With Erb's Palsy: A Case Report.

Erb's palsy usually commonly arises from incidents such as falls, collisions, birth trauma, and shoulder injuries in children. It impairs upper extremity muscle function, which has an impact on the quality of life and social interaction. Physical therapy is beneficial in preserving and enhancing upper extremity function, improving the quality of life. In this case report, a seven-year-old female child with complaints of weakness in the right upper limb demonstrated a notable increase in the strength and function of the upper extremities after four weeks of structured rehabilitation using virtual reality and functional electrical stimulation.

Comparison of the Conjunct Effects of Electrical Stimulation and Whole-Body Vibration Therapy with Transcranial Direct Current Stimulation and Whole-body Vibration Therapy on Balance and Function in Children With Spastic Cerebral Palsy.

BACKGROUND AND OBJECTIVES: Cerebral palsy is a neurodevelopmental condition that results in impaired movement and posture, often accompanied by disturbances in balance and functional abilities. Recent advances in neurorehabilitation, including whole-body vibration therapy (WBVT), functional electrical stimulation, and transcranial direct current stimulation, show promise in enhancing traditional interventions and fostering neuroplasticity. However, the efficacy of their conjunct effects remains largely uncharted territory and warrants further exploration. The objective of the study was to compare the conjunct effects of functional electrical stimulation (FES) and WBVT with transcranial direct current stimulation (tDCS) and WBVT on lower extremity range of motion (ROM), dynamic balance, functional mobility, isometric muscle strength and hand grip strength in children with spastic cerebral palsy. METHODS: A randomized clinical trial was carried out on 42 children of both genders with spastic cerebral palsy, aged 5-15 years. The children were divided at random into three groups (14 in each group). In Group A, there were three (21.42%) males and 11 (78.57%) females, in Group B, eight (57.14%) were males and six (42.85%) were females, and in Group C, six (42.85%) children were males and eight (57.14%) were females. Group A received WBVT only, Group B received WBVT and FES, and Group C received WBVT and tDCS. The intervention was applied four times a week for four consecutive weeks. The data was collected two times before and immediately after four weeks of intervention. Lower extremity ROM was measured by a goniometer, functional mobility or dynamic balance was measured by a Time Up and Go test, isometric muscle strength was measured by a digital force gauge, and hand grip strength was assessed by a digital hand-held dynamometer. IBM SPSS Statistics for Windows, Version 27.0 (Released 2020; IBM Corp., Armonk, New York, United States) was utilized for statistical analysis. RESULTS: The mean age of the children in groups A, B, and C was 12.21±2.11 years, 11.71±2.01, and 11.07±2.01 years respectively. Intergroup analysis revealed a statistically significant difference (p<0.05) in the lower extremity range of motion, and functional mobility. Hand grip strength and isometric muscle strength between three groups. Post hoc analysis revealed that WBVT with transcranial direct current stimulation combined showed the most improvement. CONCLUSION: The study concluded that positive effects were seen in all three groups but tDCS with WBVT was found to be most effective in improving lower extremity ROM, functional mobility or dynamic balance, isometric muscle strength, and hand grip strength in children with spastic CP. The differences between the groups were statistically significant. The effect size was substantial enough to surpass established clinical benchmarks, indicating that the observed improvements are likely to have meaningful and beneficial impacts on patient outcomes.

High-intensity interval training with functional electrical stimulation cycling for incomplete spinal cord injury patients: A pilot feasibility study.

BACKGROUND: Consequences of spinal cord injury (SCI) with a sedentary lifestyle will progress to muscle weakness and muscle atrophy, leading to muscle fatigue. This study aimed to determine the feasibility and preliminary effects of high-intensity interval training (HIIT) using functional electrical stimulation (FES) cycling on changes in thigh muscle volume and muscle strength, in patients with incomplete SCI. METHODS: Eight incomplete SCI patients (mean age 50 years; 6 women) with stable SCI paraplegia (mean 6.75 years since injury) participated in the HIIT FES cycling (85%-90% peak Watts; 4 × 4-min intervals) three times a week (over 6 weeks). The main outcomes were adherence, participant acceptability, and adverse events. Secondary outcomes were muscle strength (peak torque) and leg volume changes. RESULTS: Our findings revealed that the program was well-received by participants, with high levels of adherence, positive feedback, and satisfaction, suggesting that it could be a promising option for individuals seeking to enhance their lower body strength and muscle mass. Additionally, all participants successfully completed the training without any serious adverse events, indicating that the program is safe for use. Finally, we found that the 6-week HIIT FES leg cycling exercise program resulted in notable improvements in isometric peak torque of the quadriceps (range 13.9%-25.6%), hamstring muscle (18.2%-23.3%), and leg volume (1.7%-18.2%). CONCLUSIONS: This study highlights HIIT FES leg cycling exercise program potential as an effective intervention for improving lower limb muscle function.

Electrical Stimulation and Motor Function Rehabilitation in Spinal Cord Injury: A Systematic Review.

Spinal cord injury (SCI) often leads to devastating motor impairments, significantly affecting the quality of life of affected individuals. Over the last decades, spinal cord electrical stimulation seems to have encouraging effects on the motor recovery of impacted patients. This review aimed to identify clinical trials focused on motor function recovery through the application of epidural electrical stimulation, transcutaneous electrical stimulation, and functional electrical stimulation. Several clinical trials met these criteria, focusing on the impact of the aforementioned interventions on walking, standing, swimming, trunk stability, and upper extremity functionality, particularly grasp. After a thorough PubMed online database research, 37 clinical trials were included in this review, with a total of 192 patients. Many of them appeared to have an improvement in function, either clinically assessed or recorded through electromyography. This review outlines the various ways electrical stimulation techniques can aid in the motor recovery of SCI patients. It stresses the ongoing need for medical research to refine these techniques and ultimately enhance rehabilitation results in clinical settings.

A single-center, assessor-blinded, randomized controlled clinical trial to test the safety and efficacy of a novel brain-computer interface controlled functional electrical stimulation (BCI-FES) intervention for gait rehabilitation in the chronic stroke population.

BACKGROUND: In the United States, there are over seven million stroke survivors, with many facing gait impairments due to foot drop. This restricts their community ambulation and hinders functional independence, leading to several long-term health complications. Despite the best available physical therapy, gait function is incompletely recovered, and this occurs mainly during the acute phase post-stroke. Therapeutic options are limited currently. Novel therapies based on neurobiological principles have the potential to lead to long-term functional improvements. The Brain-Computer Interface (BCI) controlled Functional Electrical Stimulation (FES) system is one such strategy. It is based on Hebbian principles and has shown promise in early feasibility studies. The current study describes the BCI-FES clinical trial, which examines the safety and efficacy of this system, compared to conventional physical therapy (PT), to improve gait velocity for those with chronic gait impairment post-stroke. The trial also aims to find other secondary factors that may impact or accompany these improvements and establish the potential of Hebbian-based rehabilitation therapies. METHODS: This Phase II clinical trial is a two-arm, randomized, controlled, longitudinal study with 66 stroke participants in the chronic (> 6 months) stage of gait impairment. The participants undergo either BCI-FES paired with PT or dose-matched PT sessions (three times weekly for four weeks). The primary outcome is gait velocity (10-meter walk test), and secondary outcomes include gait endurance, range of motion, strength, sensation, quality of life, and neurophysiological biomarkers. These measures are acquired longitudinally. DISCUSSION: BCI-FES holds promise for gait velocity improvements in stroke patients. This clinical trial will evaluate the safety and efficacy of BCI-FES therapy when compared to dose-matched conventional therapy. The success of this trial will inform the potential utility of a Phase III efficacy trial. TRIAL REGISTRATION: The trial was registered as "BCI-FES Therapy for Stroke Rehabilitation" on February 19, 2020, at clinicaltrials.gov with the identifier NCT04279067.

AiCarePWP: Deep learning-based novel research for Freezing of Gait forecasting in Parkinson.

BACKGROUND AND OBJECTIVES: Episodes of Freezing of Gait (FoG) are among the most debilitating motor symptoms of Parkinson's Disease (PD), leading to falls and significantly impacting patients' quality of life. Accurate assessment of FoG by neurologists provides crucial insights into patients' conditions and disease symptoms. This proposed strategy involves utilizing a Weighted Fuzzy Logic Controller, Kalman Filter, and Kaiser-Meyer-Olkin test to detect the gait parameters while walking, resting, and standing phases. Parameters such as neuromodulation format, intensity, duration, frequency, and velocity are computed to pre-empt freezing episodes, thus aiding their prevention. METHOD: The AiCarePWP is a wearable electronics device designed to identify instances when a patient is on the brink of experiencing a freezing episode and subsequently deliver a brief electrical impulse to the patient's shank muscles to stimulate movement. The AiCarePWP wearable device aims to identify impending freezing episodes in PD patients and deliver brief electrical impulses to stimulate movement. The study validates this innovative approach using plantar insoles with a 3D accelerometer and electrical stimulator, analysing data from the inertial measuring unit and plantar-pressure foot data to detect and predict FoG. RESULTS: Using a Convolutional Neural Network-based model, the study evaluated 47 gait features for their ability to differentiate resting, standing, and walking conditions. Variable selection was based on sensitivity, specificity, and overall accuracy, followed by Principal Component Analysis and Varimax rotation to extract and interpret factors. Factors with eigenvalues exceeding 1.0 were retained, and 37 features were retained. CONCLUSION: This study validates CNN's effectiveness in detecting FoG during various activities. It introduces a novel cueing method using electrical stimulation, which improves gait function and reduces FoG incidence in PD patients. Trustworthy wearable devices, based on Artificial Intelligence of Things (AIoT) and Artificial Intelligence of Medical Things (AIoMT), have been developed to support such interventions.

A novel functional electrical stimulation sleeve based on textile-embedded dry electrodes.

BACKGROUND: Functional electrical stimulation (FES) is a rehabilitation technique that enables functional improvements in patients with motor control impairments. This study presents an original design and prototyping method for a smart sleeve for FES applications. The article explains how to integrate a carbon-based dry electrode into a textile structure and ensure an electrical connection between the electrodes and the stimulator for effective delivery of the FES. It also describes the materials and the step-by-step manufacturing processes. RESULTS: The carbon-based dry electrode is integrated into the textile substrate by a thermal compression molding process on an embroidered conductive matrix. This matrix is composed of textile silver-plated conductive yarns and is linked to the stimulator. Besides ensuring the electrical connection, the matrix improves the fixation between the textile substrate and the electrode. The stimulation intensity, the perceived comfort and the muscle torque generated by the smart FES sleeve were compared to hydrogel electrodes. The results show a better average comfort and a higher average stimulation intensity with the smart FES sleeve, while there were no significant differences for the muscle torque generated. CONCLUSIONS: The integration of the proposed dry electrodes into a textile is a viable solution. The wearable FES system does not negatively impact the electrodes' performance, and tends to improve it. Additionally, the proposed prototyping method is applicable to an entire garment in order to target all muscles. Moreover, the process is feasible for industrial production and commercialization since all materials and processes used are already available on the market.

The effect of functional electrical stimulation of the legs on cardiopulmonary function and quality of life in patients with chronic heart failure: A systematic review and meta-analysis.

Introduction: Functional electrical stimulation is important for the rehabilitation of patients with chronic heart failure. This meta-analysis of randomized controlled trials compared the efficacy of functional electrical stimulation versus conventional exercise training or placebo in patients with chronic heart failure. Methods: Studies were searched through PubMed, Embase, and the Cochrane Library databases up to 1 November 2023. The outcomes were cardiopulmonary function index (6-minute walking distance), peak oxygen consumption, and Minnesota Heart Failure Life Questionnaire quality of life scores. A subgroup analysis was conducted according to the ejection fraction. The 95% confidence interval and mean difference represented the outcome of the effect size. Results: Seventeen studies involving 732 participants were included. Compared with the control, functional electrical stimulation significantly improved peak oxygen consumption (MD = 2.84 ml/kg/min, 95% Cl: 1.99-3.68 ml/kg/min), increased 6-minute walking distance (MD = 49.52 m, 95% Cl: 22.61-76.43 m), and improved the life quality scores (MD = -12.86, 95% Cl: -17.48 to -7.88). Compared with functional electrical stimulation, exercise training also improved peak oxygen consumption (MD = -0.94 ml/kg/min-1, 95% Cl: -1.36 to -0.52 ml/kg/min), and the quality of life (QoL, MD = 0.66, 95% Cl: 0.34-0.98, p < 0.05, I 2 = 38%), but the result of 6-minute walking distance (MD = -6.97 m, 95% Cl: -18.32 to -4.38 m) did not show a difference. Further subgroup analysis showed that outcomes including the above, significantly improved under the functional electrical stimulationfor both HF patients with reduced ejection fraction and HF patients with preserved ejection fraction patients, but difference is insignificant of the results between groups of aerobic exercise and functional electrical stimulationacted on patients with HF patients with reduced ejection fraction. Conclusions: Our study demonstrates that compared with placebo, functional electrical stimulation benefits the patients with chronic heart failure on cardiopulmonary function and quality of life. Furthermore, HF patients with reduced ejection fraction patients benefit more from functional electrical stimulation than HF patients with reduced ejection fraction patients. Therefore, functional electrical stimulation is a promising complementary therapy for patients with chronic heart failure.

Effects of robot-assisted upper limb training combined with functional electrical stimulation in stroke patients: study protocol for a randomized controlled trial.

INTRODUCTION: About 17-80% stroke survivors experience the deficit of upper limb function, which strongly influences their independence and quality of life. Robot-assisted training and functional electrical stimulation are commonly used interventions in the rehabilitation of hemiplegia upper extremities, while the effect of their combination remains unclear. The aim of this trial is to explore the effect of robot-assisted upper limb training combined with functional electrical stimulation, in terms of neuromuscular rehabilitation, compared with robot-assisted upper limb training alone. METHODS: Individuals (n = 60) with the first onset of stroke (more than 1 week and less than 1 year after stroke onset) will be considered in the recruitment of this single-blinded, three-arm randomized controlled trial. Participants will be allocated into three groups (robot-assisted training combined with functional electrical stimulation group, robot-assisted training group, and conventional rehabilitation therapies group) with a ratio of 1:1:1. All interventions will be executed for 45 min per session, one session per day, 5 sessions per week for 6 weeks. The neuromuscular function of the upper limb (Fugl-Meyer Assessment of upper extremity), ability of daily life (modified Barthel Index), pain (visual analogue scale), and quality of life (EQ-5D-5L) will be assessed at the baseline, at the end of this trial and after 3 months follow-up. Two-way repeated measures analysis of variance will be used to compare the outcomes if the data are normally distributed. Simple effects tests will be used for the further exploration of interaction effects by time and group. Scheirer-Ray-Hare test will be used if the data are not satisfied with normal distribution. DISCUSSION: We expect this three-arm randomized controlled trial to explore the effectiveness of robot-assisted training combined with functional electrical stimulation in improving post-stroke upper limb function compared with robot-assisted training alone. TRIAL REGISTRATION: Effect of upper limb robot on improving upper limb function after stroke, identifier: ChiCTR2300073279. Registered on 5 July 2023.

Investigation of Motor Learning Effects Using a Hybrid Rehabilitation System Based on Motion Estimation.

Upper-limb paralysis requires extensive rehabilitation to recover functionality for everyday living, and such assistance can be supported with robot technology. Against such a background, we have proposed an electromyography (EMG)-driven hybrid rehabilitation system based on motion estimation using a probabilistic neural network. The system controls a robot and functional electrical stimulation (FES) from movement estimation using EMG signals based on the user's intention, enabling intuitive learning of joint motion and muscle contraction capacity even for multiple motions. In this study, hybrid and visual-feedback training were conducted with pointing movements involving the non-dominant wrist, and the motor learning effect was examined via quantitative evaluation of accuracy, stability, and smoothness. The results show that hybrid instruction was as effective as visual feedback training in all aspects. Accordingly, passive hybrid instruction using the proposed system can be considered effective in promoting motor learning and rehabilitation for paralysis with inability to perform voluntary movements.

Ink-based textile electrodes for wearable functional electrical stimulation: A proof-of-concept study to evaluate comfort and efficacy.

BACKGROUND: Functional Electrical Stimulation (FES) represents a promising technique for promoting functional recovery in individuals with neuromuscular diseases. Traditionally, current pulses are delivered through self-adhesive hydrogel Ag/AgCl electrodes, which allow a good contact with the skin, are easy-to-use and have a moderate cost. However, skin adherence decreases after a few uses and skin irritations can originate. Recently, textile electrodes have become an attractive alternative as they assure increased durability, easy integration into clothes and can be conveniently cleaned, improving the wearability of FES. However, as various manufacture processes were attempted, their clear validation is lacking. This proof-of-concept study proposes a novel set of ink-based printed textile electrodes and compares them to adhesive hydrogel electrodes in terms of impedance, stimulation performance and perceived comfort. METHODS: The skin-electrode impedance was evaluated for both types of electrodes under different conditions. These electrodes were then used to deliver FES to the Rectus Femoris of 14 healthy subjects to induce its contraction in both isometric and dynamic conditions. This allowed to compare the two types of electrodes in terms of sensory, motor, maximum and pain thresholds, FES-induced range of motion during dynamic tests, FES-induced torque during isometric tests and perceived stimulation comfort. RESULTS: No statistically significant differences were found both in terms of stimulation performance (Wilcoxon test) and comfort (Generalized Linear Mixed Model). CONCLUSION: The results showed that the proposed ink-based printed textile electrodes can be effectively used as alternative to hydrogel ones. Further experiments are needed to evaluate their durability and their response to sterilizability and stretching tests.

Effects of Functional Electrical Stimulation on Attention and Brain Activity in Healthy Participants Using Near-Infrared Spectroscopy: An Interventional Study.

Background Involuntary limb activation using functional electrical stimulation (FES) can improve unilateral spatial neglect. However, the impact of FES on brain activity related to spatial attention remains unclear. Thus, in this study, we aimed to examine the effects of FES on spatial attention. Methodology In this interventional study, 13 healthy right-handed participants were asked to perform the Posner task for six minutes both before and after either FES or sham stimulation during each set, resulting in a total of two sets. FES was applied to the left forearm extensor muscles, with a frequency of 25 Hz, a pulse width of 100 µs, and the intensity adjusted to reach the motor threshold. Both the energization and pause times were set to five seconds. The Posner task was used to measure reaction time to a target appearing on a computer screen. Brain activity, indicated by oxygenated hemoglobin values, was measured using near-infrared spectroscopy with 24 probes according to the International 10-20 system method. Results In the left hemisphere, oxygenated hemoglobin values in the premotor and supplementary motor areas, primary somatosensory cortex, and somatosensory association areas were significantly higher after FES than after sham stimulation. In the right hemisphere, oxygenated hemoglobin values were significantly increased in the premotor, primary, and supplementary motor areas; in the supramarginal gyrus; and in the somatosensory association areas after FES. Reaction times in the Posner task did not differ significantly between the FES and sham conditions. Conclusions Collectively, these results suggest that FES of the upper limbs can activate the ventral pathway of the visual attention network and improve stimulus-driven attention. Activation of stimulus-driven attentional function could potentially contribute to symptom improvement in patients with unilateral spatial neglect.