Bibliometric Analysis of Functional Electrical Stimulation (FES) as a Neurofeedback Tool in Brain–Computer Interface (BCI) Systems

Point: Should Phrenic Nerve Stimulation Be the Treatment of Choice for Spinal Cord Injury? Yes

For many years people have speculated that electroencephalographic activity or other electrophysiological measures of brain function might provide a new non-muscular channel for sending messages and commands to the external world – a brain–computer interface (BCI). Over the past 15 years, productive BCI research programs have arisen. Encouraged by new understanding of brain function, by the advent of powerful low-cost computer equipment, and by growing recognition of the needs and potentials of people with disabilities, these programs concentrate on developing new augmentative communication and control technology for those with severe neuromuscular disorders, such as amyotrophic lateral sclerosis, brainstem stroke, and spinal cord injury. The immediate goal is to provide these users, who may be completely paralyzed, or ‘locked in’, with basic communication capabilities so that they can express their wishes to caregivers or even operate word processing programs or neuroprostheses. Present-day BCIs determine the intent of the user from a variety of different electrophysiological signals. These signals include slow cortical potentials, P300 potentials, and mu or beta rhythms recorded from the scalp, and cortical neuronal activity recorded by implanted electrodes. They are translated in real-time into commands that operate a computer display or other device. Successful operation requires that the user encode commands in these signals and that the BCI derive the commands from the signals. Thus, the user and the BCI system need to adapt to each other both initially and continually so as to ensure stable performance. Current BCIs have maximum information transfer rates up to 10–25 bits/min. This limited capacity can be valuable for people whose severe disabilities prevent them from using conventional augmentative communication methods. At the same time, many possible applications of BCI technology, such as neuroprosthesis control, may require higher information transfer rates. Future progress will depend on: recognition that BCI research and development is an interdisciplinary problem, involving neurobiology, psychology, engineering, mathematics, and computer science; identification of those signals, whether evoked potentials, spontaneous rhythms, or neuronal firing rates, that users are best able to control independent of activity in conventional motor output pathways; development of training methods for helping users to gain and maintain that control; delineation of the best algorithms for translating these signals into device commands; attention to the identification and elimination of artifacts such as electromyographic and electro-oculographic activity; adoption of precise and objective procedures for evaluating BCI performance; recognition of the need for long-term as well as short-term assessment of BCI performance; identification of appropriate BCI applications and appropriate matching of applications and users; and attention to factors that affect user acceptance of augmentative technology, including ease of use, cosmesis, and provision of those communication and control capacities that are most important to the user. Development of BCI technology will also benefit from greater emphasis on peer-reviewed research publications and avoidance of the hyperbolic and often misleading media attention that tends to generate unrealistic expectations in the public and skepticism in other researchers. With adequate recognition and effective engagement of all these issues, BCI systems could eventually provide an important new communication and control option for those with motor disabilities and might also give those without disabilities a supplementary control channel or a control channel useful in special circumstances. q 2002 Elsevier Science Ireland Ltd. All rights reserved.

Brain–computer interfaces for communication and control

Aim: Functional electrical stimulation (FES) is a technology that can be used on paralyzed muscles to allow them to move. It has been used in populations with muscle paralysis or weakness for exercise, such as spinal cord injury (SCI) and multiple sclerosis. In order to improve technology, it is vital to understand from a qualitative perspective, issues surrounding device development and implementation.Materials and Methods: In 2016, a study was conducted at the Medical University of Vienna that sought to unravel perspectives of FES exercise from the perspective of clinicians, engineers and researchers. Semi-structured, qualitative interviews were conducted on a sample of participants from the conference (n = 22). Interviews were transcribed verbatim, and text data were analysed.Results: Following this analysis, a conceptual model of FES application in the home environment was derived. We show that the likelihood of continuing FES over time may be influenced by expectations and initial education, as perceived by stakeholders.Conclusion: This model provides a tool by which researchers or clinicians may implement FES in the home environment and may assist in the increased uptake of FES exercise at home for people who may reap benefits from its use.Implications for RehabilitationFunctional electrical stimulation (FES) is a technology that enables individuals with paralysis, such as Spinal Cord Injury or Multiple Sclerosis, to exercise.Motivation and support networks, along with adequate initial education, are essential should patients be able to successfully use FES for exercise.There are unique issues associated with performing FES in the home, and compliance may be influenced by how patients perceive FES with regard to providing benefits, and what their initial expectations are.Communication and education are essential for all parties involved in the provision of FES treatment, to ensure successful treatment with FES at home.

Brain-computer interfaces (BCIs) represent an emerging advancement in rehabilitation, enabling direct communication between the brain and external devices to aid recovery in individuals with neurological impairments. BCIs can be classified into invasive, semi-invasive, non-invasive, or hybrid types. By interpreting neural signals and converting them into control commands, BCIs can bypass damaged pathways, offering therapeutic potential for conditions such as stroke, spinal cord injury, traumatic brain injury, and neurodegenerative diseases such as amyotrophic lateral sclerosis. BCIs' current applications, such as motor restoration via robotic exoskeletons and functional electrical stimulation, cognitive enhancement through neurofeedback and attention training, and communication tools for individuals with severe physical limitations, are largely being explored within research settings and are not yet part of routine clinical practice. Advances in EEG signal acquisition, machine learning, wearable and wireless systems, and integration with virtual reality are enhancing the clinical utility of BCIs by improving accuracy, adaptability, and usability. However, widespread clinical adoption faces challenges, including signal variability, training complexity, data privacy, and ethical and regulatory issues. Ethical challenges in BCI include issues related to the ownership and misuse of brain data, risks of neural interference, threats to autonomy and personal identity, as well as concerns around data privacy, user consent, emotional manipulation, and accountability in neural interventions. In this context, this editorial has also proposed one model (NEURO model checklist) for BCI implementation in rehabilitation. The future of BCIs in rehabilitation lies in developing personalized, closed-loop, and home-based systems, enabled by interdisciplinary collaboration among clinicians, engineers, neuroscientists, and policymakers. With continued research and ethical implementation, BCIs have the potential to transform neurorehabilitation and greatly enhance patient outcomes and quality of life.

Functional Electrical Stimulation (FES) is a promising method to restore mobility to individuals paralyzed due to spinal cord injury (SCI). This method will provide the electrical pulse to the surface electrodes which are attached to paralyze part such as arm or leg and will make this part constructs because of the pulse given and can achieve the desired movement later. Depend on only FES for a rehabilitation method to SCI patient is not a very effective way. The combination between FES and Brain Computer Interface (BCI) may prove useful and effective way in SCI rehabilitation. BCI is a technology that detects a patient's intention. The main target of BCI is to create an alternative way for SCI patients between brain and others partfrom their body. This BCI will record the signal from the brain and then will transfer it to paralyze part which wants to control it. There are many methods to obtain the brain signals in BCI such as electroencephalographic (EEG) measurement technique or brain mapping technique. The EEG measurement technique is mostly used in medical rehabilitation and this technique is using EEG scalp and electrodes. The position of EEG electrodes should be correctly placed according to the appropriate movement. This paper will be discussed on the positioning of EEG electrodes for BCI-FES control system development of knee joint movement for paraplegics.

People affected by spinal cord injury (SCI) are usually unable to move their lower limbs due to inactive control of the muscles from the brain. This lack of movement may lead to further moral and physical complexities such as cardiovascular diseases, bone demineralization and bedsores. Physiotherapy based exercise and training are conventionally advised to such plegic patients, which, hereby, has not been shown to be have ample recovery efficiency. Alternatively, Functional electrical stimulation (FES) is a relatively newer technique which uses electrical signals to energize the neurons and excite the tissues in the muscles while producing the corresponding contraction in them. FES alone however requires specific electrical devices to generate and supply certain electrical signals similar to that of generated by human brain. This needs some additional devices to be used as the control system for FES to identify and issue the commands as required from time to time. A brain-computer interface (BCI) is a direct communication pathway between the brain and an external device [1]. It uses electrodes, placed on the scalp, to collect signals from the brain structure [2]. A combination of BCI and FES can be a vital solution to cater this issue, as the paralyzed patient can use his own brain electroencephalogram (EEG) as a control system to perform the required movements. This paper discusses their advantages, short comings and latest research advances in this field. Firstly, the significance of FES devices is being introduced and the different technological techniques reported in literature are discussed. Secondly, human brain is introduced as a control system to be employed within BCI systems to generate the required EEG signal activity. Finally, an incorporation of both FES and BCI is suggested to overcome the presiding issues regarding efficient control of the muscles.

Objective To discuss the effect of functional electric stimulation (FES) on motor evoked potential(MEP),glial fibrillary acidic protein (GFAP) expression and muscle wet weight in rats after spinal cord injury (SCI).Methods Seventy-two adult male SD rats were chosen and randomly divided into 3 groups:sham-operated group,FES group and model group (n=24).T9 spinal cord complete injury animal models in the FES group and model group were induced by NYU blow.Rats in the FES group were performed FES at posterior thigh and rats in the model group only placed electrode without electricity.7,14,28 and 56 d after FES,potentiometer test was performed to detect the MEP latency; immunohistochemical staining was employed to detect the GFAP expression; and hind leg extensor muscle wet weight was measured.Results The MEP latency in the FES group was detected 14,28 and 56 d after FES,which was significantly longer than that in the sham-operated group (P＜0.05); the MEP latency in the FES group 28 and 56 d after FES was significantly shortened than that in the model group (P＜0.05).Muscle wet weight in the FES group 28 and 56 d after FES was significantly increased than that in the model group (P＜0.05).GFAP-positive cells in the FES group 28 and 56 d after FES were significantly decreased than those in the model group (P＜0.05).Conclusion FES in the treatment of spinal cord injury can not only inhibit the expression of GFAP and shorten MEP latency,but also inhibit paralyzed limb muscle atrophy and promote motor function recovery. Key words: Spinal cord injury; Functional electrical stimulation; Glial fibrillary acidic protein; Muscle wet weight; Motor evoked potential

Objective: Spasticity following spinal cord injury (SCI) can impair function and affect quality of life. This study compared the effects of transcutaneous electrical nerve stimulation (TENS) and functional electrical stimulation (FES) on lower limb spasticity in patients with SCI.Design: Double blind randomized crossover design.Setting: Neuro-rehabilitation unit, Manipal University, India.Participants: Ten participants (age: 39 ± 13.6 years, C1–T11, 1–26 months post SCI) with lower limb spasticity were enrolled in this study.Interventions: Participants were administered electrical stimulation with TENS and FES (duration - 30 minutes) in a cross over manner separated by 24 hours.Outcome Measures: Spasticity was measured using modified Ashworth scale (MAS) [for hip abductors, knee extensors and ankle plantar flexors] and spinal cord assessment tool for spastic reflexes (SCATS). Assessments were performed at baseline, immediately, 1 hour, 4 hours, and 24 hours post intervention.Results: A between group analysis did not show statistically significant differences between FES and TENS (P > 0.05). In the within group analyses, TENS and FES significantly reduced spasticity up to 4 hours in hip adductors and knee extensors (P < 0.01). SCATS values showed significant reductions at 1 hour (P = 0.01) following TENS and 4 hours following FES (P = 0.01).Conclusion: A single session of electrical stimulation with FES and TENS appears to have similar anti-spasticity effects that last for 4 hours. The findings of this preliminary study suggest that both TENS and FES have the potential to be used as therapeutic adjuncts to relieve spasticity in the clinic. In addition, FES may have better effects on patients presenting with spastic reflexes.

Purpose Functional electrical stimulation (FES) can be effective in assisting physical and psychosocial difficulties experienced by people with spinal cord injury. Perceived benefits and barriers of the current and future use of FES within the wider spinal cord injury community is currently unknown. The main objective of this research was to explore the spinal cord injury community’s views of the use of FES to decrease disability in rehabilitation programmes. Materials and methods An online and paper questionnaire was distributed to people with spinal cord injury, health care professionals and researchers working in spinal cord injury settings in the United Kingdom. Results A total of 299 participants completed the survey (152 people with spinal cord injury, 141 health care professionals and 6 researchers). Common views between groups identified were: (1) FES can be beneficial in improving physical and psychosocial aspects and that (2) adequate support and training for FES application was provided to users. Barriers to FES use included a lack of staff time and training, financial cost and availability of the equipment. Sixty three percent of non-users felt they would use FES in the future if they had the opportunity. Conclusions Users’ views were important in identifying that FES application can be beneficial for people with spinal cord injury but also has some resourceful barriers. In order to increase use, future research should focus on reducing the cost of FES clinical service and also address implementation of awareness and training programmes within spinal units and community rehabilitation settings. IMPLICATIONS FOR REHABILITATION Users of functional electrical stimulation think that it is beneficial for improving physical and psychosocial limitations after spinal cord injury Barriers to FES use include a lack of staff time and training, financial cost and availability of the equipment have been suggested by people with spinal cord injury and health care professionals Education and implementation programs for health care professionals and people with spinal cord injury are now necessary to increase the awareness about functional electrical stimulation application Reduction of FES cost could also increase its uptake in spinal cord injury clinical services

A large proportion of individuals with stroke have persistent deficits for which current interventions have not restored normal motor behavior. Noninvasive brain computer interfaces (BCIs) have potential advantages for restoration of function. There are also potential advantages for combining BCI with functional electrical stimulation (FES). We tested the feasibility of combined BCI + FES for motor learning after stroke. The participant was a 43-year-old woman who was 10 months post-stroke. She was unable to produce isolated movement of any of the digits of her involved hand. With effort she exhibited simultaneous mass hyperextension of metacarpal phalangeal joints of all four fingers and thumb with simultaneous flexion of proximal interphalangeal and distal interphalangeal joints of all fingers. Brain signals from the lesioned hemisphere were used to trigger FES for movement practice. The BCI + FES intervention consisted of trials of either attempted finger movement and relax conditions or imagined finger movement and relax conditions. The training was performed three times per week for three weeks (nine sessions total). : The participant exhibited highly accurate control of brain signal in the first session for attempted movement (97%), imagined movement (83%), and some difficulties with attempted relaxation (65%). By session 6, control of relaxation (deactivation of brain signal) improved to >80%. After nine sessions (three per week) of BCI + FES intervention, the participant demonstrated recovery of volitional isolated index finger extension. BCI + FES training for motor learning after stroke was feasible. A highly accurate brain signal control was achieved, and this signal could be reliably used to trigger the FES device for isolated index finger extension. With training, volitional control of isolated finger extension was attained in a small number of sessions. The source of motor recovery could be attributable to BCI, FES, combined BCI + FES, or whole arm or hand motor task practice.

To document, through a survey, perceptions of functional electrical stimulation (FES) from people with spinal cord injury (SCI) and carers, clinicians, and researchers (CCR). Online questionnaires were completed in Australia and New Zealand from December 1, 2021 to August 31, 2022. Subgroups included people with SCI who have used FES, people with SCI who have not used FES, CCRs who have used FES, and CCRs who have not used FES. Frequencies and percentages of subgroup data were calculated for all questions. Open-ended responses were analyzed with inductive content analysis. Ninety-nine responses (70 people with SCI, 29 CCR) were analyzed. Out of the 99 responses, 47 people with SCI and 27 CCRs had used or currently use FES. Muscle strength was the most frequently reported benefit by people with SCI and CCRs who use(d) FES. Lack of training was the most frequently reported barrier to FES by people with SCI (85% of question responders) and CCRs (94%) who had used FES. People with SCI (95%) who had not used FES reported access as a barrier. The leading priorities for future research include improved ease of use for people with SCI (60% people with SCI) and clinical guidelines (48% CCR). Qualitative findings supported the quantitative findings. This survey identified access as a barrier to FES and echoed benefits (strength) and barriers (training) reported in previous research. Ameliorating the barriers and investigating the areas of future research identified in this study will ultimately improve FES uptake in SCI rehabilitation.

Functional electrical stimulation (FES) has been shown to facilitate the recovery of grasping function in individuals with incomplete spinal cord injury. Neurophysiological theory suggests that this benefit may be further enhanced by a more consistent pairing of the voluntary commands sent from the user's brain down their spinal cord with the electrical stimuli applied to the user's periphery. The objective of the study was to compare brain-machine interfaces (BMIs)-controlled and electromyogram (EMG)-controlled FES therapy to three more well-researched therapies, namely, push button-controlled FES therapy, voluntary grasping (VOL), and BMI-guided voluntary grasping. Ten able-bodied participants underwent one hour of each of five grasping training modalities, including BMI-controlled FES (BMI-FES), EMG-controlled FES (EMG-FES), conventional push button-controlled FES, VOL, and BMI-guided voluntary grasping. Assessments, including motor-evoked potential, grip force, and maximum voluntary contraction, were conducted immediately before and after each training period. Motor-evoked potential-based outcome measures were more upregulated following BMI-FES and especially EMG-FES than they were following VOL or FES. No significant changes were found in the more functional outcome measures. These results provide preliminary evidence suggesting the potential of BMI-FES and EMG-FES to induce greater neuroplastic changes than conventional therapies, although the precise mechanism behind these changes remains speculative. Further investigation will be required to elucidate the underlying mechanisms and to conclusively determine whether these effects can translate into better long-term functional outcomes and quality of life for individuals with spinal cord injury.

BackgroundParticipation in physical and therapeutic activities is usually severely restricted after a spinal cord injury (SCI). Reasons for this are the associated loss of voluntary motor function, inefficient temperature regulation of the affected extremities, and early muscle fatigue. Hydrotherapy or swim training offer an inherent weight relief, reduce spasticity and improve coordination, muscle strength and fitness.MethodsWe present a new hybrid exercise modality that combines functional electrical stimulation (FES) of the knee extensors and transcutaneous spinal cord stimulation (tSCS) with paraplegic front crawl swimming. tSCS is used to stimulate the afferent fibers of the L2–S2 posterior roots for spasticity reduction. By activating the tSCS, the trunk musculature is recruited at a motor level. This shall improve trunk stability and straighten the upper body. Within this feasibility study, two complete SCI subjects (both ASIA scale A, lesion level Th5/6), who have been proficient front crawl swimmers, conducted a 10-week swim training with stimulation support. In an additional assessment swim session nine months after the training, the knee extension, hip extension, and trunk roll angles where measured using waterproof inertial measurement units (IMUs) and compared for different swimming conditions (no stimulation, tSCS, FES, FES plus tSCS).ResultsFor both subjects, a training effect over the 10-week swim training was observed in terms of measured lap times (16 m pool) for all swimming conditions. Swimming supported by FES reduced lap times by 15.4% and 8.7% on average for Subject A and Subject B, respectively. Adding tSCS support yielded even greater mean decreases of 19.3% and 20.9% for Subjects A and B, respectively. Additionally, both subjects individually reported that swimming with tSCS for 30–45 minutes eliminated spasticity in the lower extremities for up to 4 hours beyond the duration of the session. Comparing the median as well as the interquartile range of all different settings, the IMU-based motion analysis revealed that FES as well as FES+tSCS improve knee extension in both subjects, while hip extension was only increased in one subject. Trunk roll angles were similar for all swimming conditions. tSCS had no influence on the knee and hip joint angles. Both subjects reported that stimulation-assisted swimming is comfortable, enjoyable, and they would like to use such a device for recreational training and rehabilitation in the future.ConclusionsStimulation-assisted swimming seems to be a promising new form of hybrid exercise for SCI people. It is safe to use with reusable silicone electrodes and can be performed independently by experienced paraplegic swimmers except for transfer to water. The study results indicate that swimming speed can be increased by the proposed methods and spasticity can be reduced by prolonged swim sessions with tSCS and FES. The combination of stimulation with hydrotherapy might be a promising therapy for neurologic rehabilitation in incomplete SCI, stroke or multiples sclerosis patients. Therefore, further studies shall incorporate other neurologic disorders and investigate the potential benefits of FES and tSCS therapy in the water for gait and balance.

A Comparison of Functional Electrical and Magnetic Stimulation for Propelled Cycling of Paretic Patients