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Alder G, Taylor D, Rashid U, Olsen S, Brooks T, Terry G, Niazi IK, Signal N. A Brain Computer Interface Neuromodulatory Device for Stroke Rehabilitation: Iterative User-Centered Design Approach. JMIR Rehabil Assist Technol 2023; 10:e49702. [PMID: 38079202 PMCID: PMC10750233 DOI: 10.2196/49702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/03/2023] [Accepted: 09/27/2023] [Indexed: 12/28/2023] Open
Abstract
BACKGROUND Rehabilitation technologies for people with stroke are rapidly evolving. These technologies have the potential to support higher volumes of rehabilitation to improve outcomes for people with stroke. Despite growing evidence of their efficacy, there is a lack of uptake and sustained use in stroke rehabilitation and a call for user-centered design approaches during technology design and development. This study focuses on a novel rehabilitation technology called exciteBCI, a complex neuromodulatory wearable technology in the prototype stage that augments locomotor rehabilitation for people with stroke. The exciteBCI consists of a brain computer interface, a muscle electrical stimulator, and a mobile app. OBJECTIVE This study presents the evaluation phase of an iterative user-centered design approach supported by a qualitative descriptive methodology that sought to (1) explore users' perspectives and experiences of exciteBCI and how well it fits with rehabilitation, and (2) facilitate modifications to exciteBCI design features. METHODS The iterative usability evaluation of exciteBCI was conducted in 2 phases. Phase 1 consisted of 3 sprint cycles consisting of single usability sessions with people with stroke (n=4) and physiotherapists (n=4). During their interactions with exciteBCI, participants used a "think-aloud" approach, followed by a semistructured interview. At the end of each sprint cycle, device requirements were gathered and the device was modified in preparation for the next cycle. Phase 2 focused on a "near-live" approach in which 2 people with stroke and 1 physiotherapist participated in a 3-week program of rehabilitation augmented by exciteBCI (n=3). Participants completed a semistructured interview at the end of the program. Data were analyzed from both phases using conventional content analysis. RESULTS Overall, participants perceived and experienced exciteBCI positively, while providing guidance for iterative changes. Five interrelated themes were identified from the data: (1) "This is rehab" illustrated that participants viewed exciteBCI as having a good fit with rehabilitation practice; (2) "Getting the most out of rehab" highlighted that exciteBCI was perceived as a means to enhance rehabilitation through increased engagement and challenge; (3) "It is a tool not a therapist," revealed views that the technology could either enhance or disrupt the therapeutic relationship; and (4) "Weighing up the benefits versus the burden" and (5) "Don't make me look different" emphasized important design considerations related to device set-up, use, and social acceptability. CONCLUSIONS This study offers several important findings that can inform the design and implementation of rehabilitation technologies. These include (1) the design of rehabilitation technology should support the therapeutic relationship between the patient and therapist, (2) social acceptability is a design priority in rehabilitation technology but its importance varies depending on the use context, and (3) there is value in using design research methods that support understanding usability in the context of sustained use.
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Affiliation(s)
- Gemma Alder
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Denise Taylor
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Usman Rashid
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Sharon Olsen
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Thonia Brooks
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Gareth Terry
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Imran Khan Niazi
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
- Sensory Motor Integration, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Nada Signal
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
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Jia H, Sun Z, Duan F, Zhang Y, Caiafa CF, Solé-Casals J. Improving pre-movement pattern detection with filter bank selection. J Neural Eng 2022; 19. [PMID: 36317288 DOI: 10.1088/1741-2552/ac9e75] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 10/28/2022] [Indexed: 11/17/2022]
Abstract
Objective. Pre-movement decoding plays an important role in detecting the onsets of actions using low-frequency electroencephalography (EEG) signals before the movement of an upper limb. In this work, a binary classification method is proposed between two different states.Approach. The proposed method, referred to as filter bank standard task-related component analysis (FBTRCA), is to incorporate filter bank selection into the standard task-related component analysis (STRCA) method. In FBTRCA, the EEG signals are first divided into multiple sub-bands which start at specific fixed frequencies and end frequencies that follow in an arithmetic sequence. The STRCA method is then applied to the EEG signals in these bands to extract CCPs. The minimum redundancy maximum relevance feature selection method is used to select essential features from these correlation patterns in all sub-bands. Finally, the selected features are classified using the binary support vector machine classifier. A convolutional neural network (CNN) is an alternative approach to select canonical correlation patterns.Main Results. Three methods were evaluated using EEG signals in the time window from 2 s before the movement onset to 1 s after the movement onset. In the binary classification between a movement state and the resting state, the FBTRCA achieved an average accuracy of 0.8968 ± 0.0847 while the accuracies of STRCA and CNN were 0.8228 ± 0.1149 and 0.8828 ± 0.0917, respectively. In the binary classification between two actions, the accuracies of STRCA, CNN, and FBTRCA were 0.6611 ± 0.1432, 0.6993 ± 0.1271, 0.7178 ± 0.1274, respectively. Feature selection using filter banks, as in FBTRCA, produces comparable results to STRCA.Significance. The proposed method provides a way to select filter banks in pre-movement decoding, and thus it improves the classification performance. The improved pre-movement decoding of single upper limb movements is expected to provide people with severe motor disabilities with a more natural, non-invasive control of their external devices.
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Affiliation(s)
- Hao Jia
- Data and Signal Processing Research Group, University of Vic-Central University of Catalonia, Vic, Catalonia, Spain
| | - Zhe Sun
- Computational Engineering Applications Unit, Head Office for Information Systems and Cybersecurity, RIKEN, Saitama, Japan
| | - Feng Duan
- Tianjin Key Laboratory of Brain Science and Intelligent Rehabilitation, College of Artificial Intelligence, Nankai University, Tianjin, People's Republic of China
| | - Yu Zhang
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, United States of America.,Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA, 18015, United States of America
| | - Cesar F Caiafa
- Instituto Argentino de Radioastronomía, CONICET CCT La Plata/CIC-PBA/UNLP, V. Elisa, Argentina
| | - Jordi Solé-Casals
- Data and Signal Processing Research Group, University of Vic-Central University of Catalonia, Vic, Catalonia, Spain.,Department of Psychiatry, University of Cambridge, Cambridge CB2 3EB, United Kingdom
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Niazi IK, Navid MS, Rashid U, Amjad I, Olsen S, Haavik H, Alder G, Kumari N, Signal N, Taylor D, Farina D, Jochumsen M. Associative cued asynchronous BCI induces cortical plasticity in stroke patients. Ann Clin Transl Neurol 2022; 9:722-733. [PMID: 35488791 PMCID: PMC9082379 DOI: 10.1002/acn3.51551] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/14/2022] [Accepted: 03/12/2022] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE We propose a novel cue-based asynchronous brain-computer interface(BCI) for neuromodulation via the pairing of endogenous motor cortical activity with the activation of somatosensory pathways. METHODS The proposed BCI detects the intention to move from single-trial EEG signals in real time, but, contrary to classic asynchronous-BCI systems, the detection occurs only during time intervals when the patient is cued to move. This cue-based asynchronous-BCI was compared with two traditional BCI modes (asynchronous-BCI and offline synchronous-BCI) and a control intervention in chronic stroke patients. The patients performed ankle dorsiflexion movements of the paretic limb in each intervention while their brain signals were recorded. BCI interventions decoded the movement attempt and activated afferent pathways via electrical stimulation. Corticomotor excitability was assessed using motor-evoked potentials in the tibialis-anterior muscle induced by transcranial magnetic stimulation before, immediately after, and 30 min after the intervention. RESULTS The proposed cue-based asynchronous-BCI had significantly fewer false positives/min and false positives/true positives (%) as compared to the previously developed asynchronous-BCI. Linear-mixed-models showed that motor-evoked potential amplitudes increased following all BCI modes immediately after the intervention compared to the control condition (p <0.05). The proposed cue-based asynchronous-BCI resulted in the largest relative increase in peak-to-peak motor-evoked potential amplitudes(141% ± 33%) among all interventions and sustained it for 30 min(111% ± 33%). INTERPRETATION These findings prove the high performance of a newly proposed cue-based asynchronous-BCI intervention. In this paradigm, individuals receive precise instructions (cue) to promote engagement, while the timing of brain activity is accurately detected to establish a precise association with the delivery of sensory input for plasticity induction.
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Affiliation(s)
- Imran Khan Niazi
- Health and Rehabilitation Research Institute and BioDesign LabAuckland University of TechnologyAucklandNew Zealand
- SMI, Department of Health Science and TechnologyAalborg UniversityAalborgDenmark
- Centre for Chiropractic ResearchNew Zealand College of ChiropracticAucklandNew Zealand
| | - Muhammad Samran Navid
- Centre for Chiropractic ResearchNew Zealand College of ChiropracticAucklandNew Zealand
| | - Usman Rashid
- Health and Rehabilitation Research Institute and BioDesign LabAuckland University of TechnologyAucklandNew Zealand
| | - Imran Amjad
- Centre for Chiropractic ResearchNew Zealand College of ChiropracticAucklandNew Zealand
- Riphah International UniversityIslamabadPakistan
| | - Sharon Olsen
- Health and Rehabilitation Research Institute and BioDesign LabAuckland University of TechnologyAucklandNew Zealand
| | - Heidi Haavik
- Centre for Chiropractic ResearchNew Zealand College of ChiropracticAucklandNew Zealand
| | - Gemma Alder
- Health and Rehabilitation Research Institute and BioDesign LabAuckland University of TechnologyAucklandNew Zealand
| | - Nitika Kumari
- Health and Rehabilitation Research Institute and BioDesign LabAuckland University of TechnologyAucklandNew Zealand
- Centre for Chiropractic ResearchNew Zealand College of ChiropracticAucklandNew Zealand
| | - Nada Signal
- Health and Rehabilitation Research Institute and BioDesign LabAuckland University of TechnologyAucklandNew Zealand
| | - Denise Taylor
- Health and Rehabilitation Research Institute and BioDesign LabAuckland University of TechnologyAucklandNew Zealand
| | - Dario Farina
- Department of BioengineeringImperial College LondonLondonUK
| | - Mads Jochumsen
- SMI, Department of Health Science and TechnologyAalborg UniversityAalborgDenmark
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Scano A, Mira RM, Gabbrielli G, Molteni F, Terekhov V. Whole-Body Adaptive Functional Electrical Stimulation Kinesitherapy Can Promote the Restoring of Physiological Muscle Synergies for Neurological Patients. SENSORS 2022; 22:s22041443. [PMID: 35214345 PMCID: PMC8877830 DOI: 10.3390/s22041443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/28/2022] [Accepted: 02/11/2022] [Indexed: 12/03/2022]
Abstract
Background: Neurological diseases and traumas are major factors that may reduce motor functionality. Functional electrical stimulation is a technique that helps regain motor function, assisting patients in daily life activities and in rehabilitation practices. In this study, we evaluated the efficacy of a treatment based on whole-body Adaptive Functional Electrical Stimulation Kinesitherapy (AFESK™) with the use of muscle synergies, a well-established method for evaluation of motor coordination. The evaluation is performed on retrospectively gathered data of neurological patients executing whole-body movements before and after AFESK-based treatments. Methods: Twenty-four chronic neurologic patients and 9 healthy subjects were recruited in this study. The patient group was further subdivided in 3 subgroups: hemiplegic, tetraplegic and paraplegic. All patients underwent two acquisition sessions: before treatment and after a FES based rehabilitation treatment at the VIKTOR Physio Lab. Patients followed whole-body exercise protocols tailored to their needs. The control group of healthy subjects performed all movements in a single session and provided reference data for evaluating patients’ performance. sEMG was recorded on relevant muscles and muscle synergies were extracted for each patient’s EMG data and then compared to the ones extracted from the healthy volunteers. To evaluate the effect of the treatment, the motricity index was measured and patients’ extracted synergies were compared to the control group before and after treatment. Results: After the treatment, patients’ motricity index increased for many of the screened body segments. Muscle synergies were more similar to those of healthy people. Globally, the normalized synergy similarity in respect to the control group was 0.50 before the treatment and 0.60 after (p < 0.001), with improvements for each subgroup of patients. Conclusions: AFESK treatment induced favorable changes in muscle activation patterns in chronic neurologic patients, partially restoring muscular patterns similar to healthy people. The evaluation of the synergic relationships of muscle activity when performing test exercises allows to assess the results of rehabilitation measures in patients with impaired locomotor functions.
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Affiliation(s)
- Alessandro Scano
- UOS STIIMA Lecco—Human-Centered, Smart & Safe, Living Environment, Italian National Research Council (CNR), Via Previati 1/E, 23900 Lecco, Italy;
- Correspondence: (A.S.); (V.T.)
| | - Robert Mihai Mira
- UOS STIIMA Lecco—Human-Centered, Smart & Safe, Living Environment, Italian National Research Council (CNR), Via Previati 1/E, 23900 Lecco, Italy;
| | | | - Franco Molteni
- Villa Beretta Rehabilitation Center, Ospedale Valduce, Via N. Sauro 17, 23845 Costa Masnaga, Italy;
| | - Viktor Terekhov
- VIKTOR S.r.l.—Via Pasubio, 5, 24044 Dalmine (BG), Italy;
- Correspondence: (A.S.); (V.T.)
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Olsen S, Alder G, Williams M, Chambers S, Jochumsen M, Signal N, Rashid U, Niazi IK, Taylor D. Electroencephalographic Recording of the Movement-Related Cortical Potential in Ecologically Valid Movements: A Scoping Review. Front Neurosci 2021; 15:721387. [PMID: 34650399 PMCID: PMC8505671 DOI: 10.3389/fnins.2021.721387] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/27/2021] [Indexed: 12/05/2022] Open
Abstract
The movement-related cortical potential (MRCP) is a brain signal that can be recorded using surface electroencephalography (EEG) and represents the cortical processes involved in movement preparation. The MRCP has been widely researched in simple, single-joint movements, however, these movements often lack ecological validity. Ecological validity refers to the generalizability of the findings to real-world situations, such as neurological rehabilitation. This scoping review aimed to synthesize the research evidence investigating the MRCP in ecologically valid movement tasks. A search of six electronic databases identified 102 studies that investigated the MRCP during multi-joint movements; 59 of these studies investigated ecologically valid movement tasks and were included in the review. The included studies investigated 15 different movement tasks that were applicable to everyday situations, but these were largely carried out in healthy populations. The synthesized findings suggest that the recording and analysis of MRCP signals is possible in ecologically valid movements, however the characteristics of the signal appear to vary across different movement tasks (i.e., those with greater complexity, increased cognitive load, or a secondary motor task) and different populations (i.e., expert performers, people with Parkinson’s Disease, and older adults). The scarcity of research in clinical populations highlights the need for further research in people with neurological and age-related conditions to progress our understanding of the MRCPs characteristics and to determine its potential as a measure of neurological recovery and intervention efficacy. MRCP-based neuromodulatory interventions applied during ecologically valid movements were only represented in one study in this review as these have been largely delivered during simple joint movements. No studies were identified that used ecologically valid movements to control BCI-driven external devices; this may reflect the technical challenges associated with accurately classifying functional movements from MRCPs. Future research investigating MRCP-based interventions should use movement tasks that are functionally relevant to everyday situations. This will facilitate the application of this knowledge into the rehabilitation setting.
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Affiliation(s)
- Sharon Olsen
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Gemma Alder
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Mitra Williams
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Seth Chambers
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Mads Jochumsen
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Nada Signal
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Usman Rashid
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand.,Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
| | - Imran Khan Niazi
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand.,Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.,Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
| | - Denise Taylor
- Rehabilitation Innovation Centre, Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
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Alder G, Signal N, Vandal AC, Olsen S, Jochumsen M, Niazi IK, Taylor D. Investigating the Intervention Parameters of Endogenous Paired Associative Stimulation (ePAS). Brain Sci 2021; 11:brainsci11020224. [PMID: 33673171 PMCID: PMC7918620 DOI: 10.3390/brainsci11020224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/20/2021] [Accepted: 02/04/2021] [Indexed: 11/16/2022] Open
Abstract
Advances in our understanding of neural plasticity have prompted the emergence of neuromodulatory interventions, which modulate corticomotor excitability (CME) and hold potential for accelerating stroke recovery. Endogenous paired associative stimulation (ePAS) involves the repeated pairing of a single pulse of peripheral electrical stimulation (PES) with endogenous movement-related cortical potentials (MRCPs), which are derived from electroencephalography. However, little is known about the optimal parameters for its delivery. A factorial design with repeated measures delivered four different versions of ePAS, in which PES intensities and movement type were manipulated. Linear mixed models were employed to assess interaction effects between PES intensity (suprathreshold (Hi) and motor threshold (Lo)) and movement type (Voluntary and Imagined) on CME. ePAS interventions significantly increased CME compared to control interventions, except in the case of Lo-Voluntary ePAS. There was an overall main effect for the Hi-Voluntary ePAS intervention immediately post-intervention (p = 0.002), with a sub-additive interaction effect at 30 min’ post-intervention (p = 0.042). Hi-Imagined and Lo-Imagined ePAS significantly increased CME for 30 min post-intervention (p = 0.038 and p = 0.043 respectively). The effects of the two PES intensities were not significantly different. CME was significantly greater after performing imagined movements, compared to voluntary movements, with motor threshold PES (Lo) 15 min post-intervention (p = 0.012). This study supports previous research investigating Lo-Imagined ePAS and extends those findings by illustrating that ePAS interventions that deliver suprathreshold intensities during voluntary or imagined movements (Hi-Voluntary and Hi-Imagined) also increase CME. Importantly, our findings indicate that stimulation intensity and movement type interact in ePAS interventions. Factorial designs are an efficient way to explore the effects of manipulating the parameters of neuromodulatory interventions. Further research is required to ensure that these parameters are appropriately refined to maximise intervention efficacy for people with stroke and to support translation into clinical practice.
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Affiliation(s)
- Gemma Alder
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (S.O.); (I.K.N.); (D.T.)
- Correspondence:
| | - Nada Signal
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (S.O.); (I.K.N.); (D.T.)
| | - Alain C. Vandal
- Department of Statistics, University of Auckland, Auckland 1142, New Zealand;
- Ko Awatea, Counties Manukau Health, Auckland 2025, New Zealand
| | - Sharon Olsen
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (S.O.); (I.K.N.); (D.T.)
| | - Mads Jochumsen
- Department of Health Science and Technology, Aalborg University, 9000 Aalborg, Denmark;
| | - Imran Khan Niazi
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (S.O.); (I.K.N.); (D.T.)
- Department of Health Science and Technology, Aalborg University, 9000 Aalborg, Denmark;
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand
| | - Denise Taylor
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (S.O.); (I.K.N.); (D.T.)
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Induction of Neural Plasticity Using a Low-Cost Open Source Brain-Computer Interface and a 3D-Printed Wrist Exoskeleton. SENSORS 2021; 21:s21020572. [PMID: 33467420 PMCID: PMC7830618 DOI: 10.3390/s21020572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/08/2021] [Accepted: 01/12/2021] [Indexed: 11/16/2022]
Abstract
Brain-computer interfaces (BCIs) have been proven to be useful for stroke rehabilitation, but there are a number of factors that impede the use of this technology in rehabilitation clinics and in home-use, the major factors including the usability and costs of the BCI system. The aims of this study were to develop a cheap 3D-printed wrist exoskeleton that can be controlled by a cheap open source BCI (OpenViBE), and to determine if training with such a setup could induce neural plasticity. Eleven healthy volunteers imagined wrist extensions, which were detected from single-trial electroencephalography (EEG), and in response to this, the wrist exoskeleton replicated the intended movement. Motor-evoked potentials (MEPs) elicited using transcranial magnetic stimulation were measured before, immediately after, and 30 min after BCI training with the exoskeleton. The BCI system had a true positive rate of 86 ± 12% with 1.20 ± 0.57 false detections per minute. Compared to the measurement before the BCI training, the MEPs increased by 35 ± 60% immediately after and 67 ± 60% 30 min after the BCI training. There was no association between the BCI performance and the induction of plasticity. In conclusion, it is possible to detect imaginary movements using an open-source BCI setup and control a cheap 3D-printed exoskeleton that when combined with the BCI can induce neural plasticity. These findings may promote the availability of BCI technology for rehabilitation clinics and home-use. However, the usability must be improved, and further tests are needed with stroke patients.
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8
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Olsen S, Signal N, Niazi IK, Rashid U, Alder G, Mawston G, Nedergaard RB, Jochumsen M, Taylor D. Peripheral Electrical Stimulation Paired With Movement-Related Cortical Potentials Improves Isometric Muscle Strength and Voluntary Activation Following Stroke. Front Hum Neurosci 2020; 14:156. [PMID: 32499686 PMCID: PMC7242792 DOI: 10.3389/fnhum.2020.00156] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 04/09/2020] [Indexed: 12/18/2022] Open
Abstract
Background Endogenous paired associative stimulation (ePAS) is a neuromodulatory intervention that has potential to aid stroke recovery. ePAS involves pairing endogenous electroencephalography (EEG) signals known as movement-related cortical potentials (MRCPs), with peripheral electrical stimulation. Previous studies have used transcranial magnetic stimulation (TMS) to demonstrate changes in corticomotor excitability following ePAS. However, the use of TMS as a measure in stroke research is limited by safety precautions, intolerance, and difficulty generating a measurable response in more severely affected individuals. We were interested in evaluating the effect of ePAS using more feasible measures in people with stroke. This study asks whether ePAS produces immediate improvements in the primary outcomes of maximal voluntary isometric contraction (MVIC) and total neuromuscular fatigue of the dorsiflexor muscles, and in the secondary outcomes of muscle power, voluntary activation (VA), central fatigue, peripheral fatigue, and electromyography activity. Method In this repeated-measures cross-over study, 15 participants with chronic stroke completed two interventions, ePAS and sham, in a randomized order. During ePAS, 50 repetitions of visually cued dorsiflexion were completed, while single pulses of electrical stimulation were delivered to the deep branch of the common peroneal nerve. Each somatosensory volley was timed to arrive in the primary motor cortex at the peak negativity of the MRCP. Univariate and multivariate linear mixed models were used to analyze the primary and secondary data, respectively. Results There was a statistically significant increase in dorsiflexor MVIC immediately following the ePAS intervention (mean increase 7 N), compared to the sham intervention (mean change 0 N) (univariate between-condition analysis p = 0.047). The multivariate analysis revealed a statistically significant effect of ePAS on VA of the tibialis anterior muscle, such that ePAS increased VA by 7 percentage units (95% confidence interval 1.3–12.7%). There was no statistically significant effect on total neuromuscular fatigue, muscle power, or other secondary measures. Conclusion A single session of ePAS can significantly increase isometric muscle strength and VA in people with chronic stroke. The findings confirm that ePAS has a central neuromodulatory mechanism and support further exploration of its potential as an adjunct to stroke rehabilitation. In addition, the findings offer alternative, feasible outcome measures for future research. Clinical trial registration Australia New Zealand Clinical Trials Registry ACTRN12617000838314 (www.anzctr.org.au), Universal Trial Number U111111953714.
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Affiliation(s)
- Sharon Olsen
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Nada Signal
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Imran K Niazi
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand.,Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand.,Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Usman Rashid
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Gemma Alder
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Grant Mawston
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Rasmus B Nedergaard
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.,Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Mads Jochumsen
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Denise Taylor
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
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9
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Alder G, Signal N, Rashid U, Olsen S, Niazi IK, Taylor D. Intra- and Inter-Rater Reliability of Manual Feature Extraction Methods in Movement Related Cortical Potential Analysis. SENSORS (BASEL, SWITZERLAND) 2020; 20:E2427. [PMID: 32344692 PMCID: PMC7219488 DOI: 10.3390/s20082427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/16/2020] [Accepted: 04/20/2020] [Indexed: 11/17/2022]
Abstract
Event related potentials (ERPs) provide insight into the neural activity generated in response to motor, sensory and cognitive processes. Despite the increasing use of ERP data in clinical research little is known about the reliability of human manual ERP labelling methods. Intra-rater and inter-rater reliability were evaluated in five electroencephalography (EEG) experts who labelled the peak negativity of averaged movement related cortical potentials (MRCPs) derived from thirty datasets. Each dataset contained 50 MRCP epochs from healthy people performing cued voluntary or imagined movement, or people with stroke performing cued voluntary movement. Reliability was assessed using the intraclass correlation coefficient and standard error of measurement. Excellent intra- and inter-rater reliability was demonstrated in the voluntary movement conditions in healthy people and people with stroke. In comparison reliability in the imagined condition was low to moderate. Post-hoc secondary epoch analysis revealed that the morphology of the signal contributed to the consistency of epoch inclusion; potentially explaining the differences in reliability seen across conditions. Findings from this study may inform future research focused on developing automated labelling methods for ERP feature extraction and call to the wider community of researchers interested in utilizing ERPs as a measure of neurophysiological change or in the delivery of EEG-driven interventions.
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Affiliation(s)
- Gemma Alder
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (U.R.); (S.O.); (I.K.N.); (D.T.)
| | - Nada Signal
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (U.R.); (S.O.); (I.K.N.); (D.T.)
| | - Usman Rashid
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (U.R.); (S.O.); (I.K.N.); (D.T.)
| | - Sharon Olsen
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (U.R.); (S.O.); (I.K.N.); (D.T.)
| | - Imran Khan Niazi
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (U.R.); (S.O.); (I.K.N.); (D.T.)
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand
| | - Denise Taylor
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand; (N.S.); (U.R.); (S.O.); (I.K.N.); (D.T.)
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10
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Fu L, Rocchi L, Hannah R, Xu G, Rothwell JC, Ibáñez J. Corticospinal excitability modulation by pairing peripheral nerve stimulation with cortical states of movement initiation. J Physiol 2019; 599:2471-2482. [PMID: 31579945 DOI: 10.1113/jp278536] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/30/2019] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS We compare the effects on corticospinal excitability of repeatedly delivering peripheral nerve stimulation at three time points (-30 ms, 0 ms, +50 ms) relative to muscle onset in a cue-guided task. Plastic changes in excitability are only observed when stimuli are delivered immediately before the time when muscles activate, while stimuli delivered at muscle onset or shortly later (0, +50 ms) have no effect. Plastic effects are abolished if there is ongoing volitional electromyogram activity in the muscles prior to the onset of the phasic contraction. The plastic effects induced by timing peripheral stimulation relative to electromyographic markers of muscle activation are as effective as those that occur if stimulation is timed relative to electroencephalographic markers of motor cortical activation. We provide a simple alternative protocol to induce plasticity in people in whom electroencephalogram recording is difficult. ABSTRACT Plastic changes in corticospinal excitability (CSE) and motor function can be induced in a targeted and long-term manner if afferent volleys evoked by peripheral nerve stimulation are repeatedly associated with the peak of premovement brain activity assessed with an electroencephalogram (EEG). The present study investigated whether other factors might also characterize this optimal brain state for plasticity induction. In healthy human volunteers (n = 24), we found that the same reliable changes in CSE can be induced by timing peripheral afferent stimulation relative to the onset of electromyogram (EMG) activity rather than using the EEG peak. Specifically, we observed an increase in CSE when peripheral stimulation activated the cortex just before movement initiation. By contrast, there was no effect on CSE if the afferent input reached the cortex at the same time or after EMG onset, consistent with the idea that the temporal order of synaptic activation from afferent input and voluntary movement is important for production of plasticity. Finally, in 14 volunteers, we found that background voluntary muscle activity prior to movement also abolished the effect on CSE. One possible explanation is that the intervention strengthens synapses that are inactive at rest but change their activity in anticipation of movement, and that the intervention fails when the synapses are tonically active during background EMG activity. Overall, we demonstrate that, in individuals with voluntary control of muscles targeted by our intervention, EMG signals are a suitable alternative to an EEG for inducing plasticity by coupling movement-related brain states with peripheral afferent input.
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Affiliation(s)
- Lingdi Fu
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Electrical Engineering, Hebei University of Technology, Tianjin, China.,Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, School of Electrical Engineering, Hebei University of Technology, Tianjin, China
| | - Lorenzo Rocchi
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Ricci Hannah
- Department of Psychology, University of California San Diego, San Diego, CA, USA
| | - Guizhi Xu
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Electrical Engineering, Hebei University of Technology, Tianjin, China.,Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, School of Electrical Engineering, Hebei University of Technology, Tianjin, China
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Jaime Ibáñez
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK.,Department of Bioengineering, Faculty of Engineering, Imperial College London, London, UK
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11
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Carson RG, Buick AR. Neuromuscular electrical stimulation-promoted plasticity of the human brain. J Physiol 2019; 599:2375-2399. [PMID: 31495924 DOI: 10.1113/jp278298] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/16/2019] [Indexed: 12/21/2022] Open
Abstract
The application of neuromuscular electrical stimulation (NMES) to paretic limbs has demonstrated utility for motor rehabilitation following brain injury. When NMES is delivered to a mixed peripheral nerve, typically both efferent and afferent fibres are recruited. Muscle contractions brought about by the excitation of motor neurons are often used to compensate for disability by assisting actions such as the formation of hand aperture, or by preventing others including foot drop. In this context, exogenous stimulation provides a direct substitute for endogenous neural drive. The goal of the present narrative review is to describe the means through which NMES may also promote sustained adaptations within central motor pathways, leading ultimately to increases in (intrinsic) functional capacity. There is an obvious practical motivation, in that detailed knowledge concerning the mechanisms of adaptation has the potential to inform neurorehabilitation practice. In addition, responses to NMES provide a means of studying CNS plasticity at a systems level in humans. We summarize the fundamental aspects of NMES, focusing on the forms that are employed most commonly in clinical and experimental practice. Specific attention is devoted to adjuvant techniques that further promote adaptive responses to NMES thereby offering the prospect of increased therapeutic potential. The emergent theme is that an association with centrally initiated neural activity, whether this is generated in the context of NMES triggered by efferent drive or via indirect methods such as mental imagery, may in some circumstances promote the physiological changes that can be induced through peripheral electrical stimulation.
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Affiliation(s)
- Richard G Carson
- Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin 2, Ireland.,School of Psychology, Queen's University Belfast, Belfast, BT7 1NN, UK.,School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - Alison R Buick
- School of Psychology, Queen's University Belfast, Belfast, BT7 1NN, UK
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12
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Alder G, Signal N, Olsen S, Taylor D. A Systematic Review of Paired Associative Stimulation (PAS) to Modulate Lower Limb Corticomotor Excitability: Implications for Stimulation Parameter Selection and Experimental Design. Front Neurosci 2019; 13:895. [PMID: 31507367 PMCID: PMC6718871 DOI: 10.3389/fnins.2019.00895] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/09/2019] [Indexed: 12/15/2022] Open
Abstract
Non-invasive neuromodulatory interventions have the potential to influence neural plasticity and augment motor rehabilitation in people with stroke. Paired associative stimulation (PAS) involves the repeated pairing of single pulses of electrical stimulation to a peripheral nerve and single pulses of transcranial magnetic stimulation over the contralateral primary motor cortex. Efficacy of PAS in the lower limb of healthy and stroke populations has not been systematically appraised. Optimal protocols including stimulation parameter settings have yet to be determined. This systematic review (a) examines the efficacy of PAS on lower limb corticomotor excitability in healthy and stroke populations and (b) evaluates the stimulation parameters employed. Five databases were searched for randomized, non-randomized, and pre-post experimental studies evaluating lower limb PAS in healthy and stroke populations. Two independent reviewers identified eligible studies and assessed methodological quality using a modified Downs and Blacks Tool and the TMS Checklist. Intervention stimulation parameters and TMS measurement details were also extracted and compared. Twelve articles, comprising 24 experiments, met the inclusion criteria. Four articles evaluated PAS in people with stroke. Following a single session of PAS, 21 experiments reported modulation of corticomotor excitability, lasting up to 60 min; however, the research lacked methodological rigor. Intervention stimulation parameters were highly variable across experiments, and whilst these appeared to influence efficacy, variations in the intervention and outcome assessment methods hindered the ability to draw conclusions about optimal parameters. Lower limb PAS research requires further investigation before considering its translation into clinical practice. Eight key recommendations serve as guide for enhancing future research in the field.
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Affiliation(s)
- Gemma Alder
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Nada Signal
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Sharon Olsen
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Denise Taylor
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
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13
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Jochumsen M, Navid MS, Rashid U, Haavik H, Niazi IK. EMG- Versus EEG-Triggered Electrical Stimulation for Inducing Corticospinal Plasticity. IEEE Trans Neural Syst Rehabil Eng 2019; 27:1901-1908. [PMID: 31380763 DOI: 10.1109/tnsre.2019.2932104] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Brain-computer interfaces have been proposed for stroke rehabilitation. Motor cortical activity derived from the electroencephalography (EEG) can trigger external devices that provide congruent sensory feedback. However, many stroke patients regain residual muscle (EMG: electromyography) control due to spontaneous recovery and rehabilitation; therefore, EEG may not be necessary as a control signal. In this paper, a direct comparison was made between the induction of corticospinal plasticity using either EEG- or EMG-controlled electrical nerve stimulation. Twenty healthy participants participated in two intervention sessions consisting of EEG- and EMG-controlled electrical stimulation. The sessions consisted of 50 pairings between foot dorsiflexion movements (decoded through either EEG or EMG) and electrical stimulation of the common peroneal nerve. Before, immediately after and 30 minutes after the intervention, 15 motor evoked potentials (MEPs) were elicited in tibialis anterior through transcranial magnetic stimulation. Increased MEPs were observed immediately after (62 ± 26%, 73 ± 27% for EEG- and EMG-triggered electrical stimulation, respectively) and 30 minutes after each of the two interventions (79 ± 26% and 72 ± 27%) compared to the pre-intervention measurement. There was no difference between the interventions. Both EEG- and EMG-controlled electrical stimulation can induce corticospinal plasticity which suggests that stroke patients with residual EMG can use that modality instead of EEG to trigger stimulation.
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14
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Self-Paced Online vs. Cue-Based Offline Brain-Computer Interfaces for Inducing Neural Plasticity. Brain Sci 2019; 9:brainsci9060127. [PMID: 31159454 PMCID: PMC6627467 DOI: 10.3390/brainsci9060127] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/23/2019] [Accepted: 05/28/2019] [Indexed: 02/01/2023] Open
Abstract
: Brain-computer interfaces (BCIs), operated in a cue-based (offline) or self-paced (online) mode, can be used for inducing cortical plasticity for stroke rehabilitation by the pairing of movement-related brain activity with peripheral electrical stimulation. The aim of this study was to compare the difference in cortical plasticity induced by the two BCI modes. Fifteen healthy participants participated in two experimental sessions: cue-based BCI and self-paced BCI. In both sessions, imagined dorsiflexions were extracted from continuous electroencephalogram (EEG) and paired 50 times with the electrical stimulation of the common peroneal nerve. Before, immediately after, and 30 minutes after each intervention, the cortical excitability was measured through the motor-evoked potentials (MEPs) of tibialis anterior elicited through transcranial magnetic stimulation. Linear mixed regression models showed that the MEP amplitudes increased significantly (p < 0.05) from pre- to post- and 30-minutes post-intervention in terms of both the absolute and relative units, regardless of the intervention type. Compared to pre-interventions, the absolute MEP size increased by 79% in post- and 68% in 30-minutes post-intervention in the self-paced mode (with a true positive rate of ~75%), and by 37% in post- and 55% in 30-minutes post-intervention in the cue-based mode. The two modes were significantly different (p = 0.03) at post-intervention (relative units) but were similar at both post timepoints (absolute units). These findings suggest that immediate changes in cortical excitability may have implications for stroke rehabilitation, where it could be used as a priming protocol in conjunction with another intervention; however, the findings need to be validated in studies involving stroke patients.
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15
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Jochumsen M, Cremoux S, Robinault L, Lauber J, Arceo JC, Navid MS, Nedergaard RW, Rashid U, Haavik H, Niazi IK. Investigation of Optimal Afferent Feedback Modality for Inducing Neural Plasticity with A Self-Paced Brain-Computer Interface. SENSORS 2018; 18:s18113761. [PMID: 30400325 PMCID: PMC6264113 DOI: 10.3390/s18113761] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 10/26/2018] [Accepted: 11/01/2018] [Indexed: 11/16/2022]
Abstract
Brain-computer interfaces (BCIs) can be used to induce neural plasticity in the human nervous system by pairing motor cortical activity with relevant afferent feedback, which can be used in neurorehabilitation. The aim of this study was to identify the optimal type or combination of afferent feedback modalities to increase cortical excitability in a BCI training intervention. In three experimental sessions, 12 healthy participants imagined a dorsiflexion that was decoded by a BCI which activated relevant afferent feedback: (1) electrical nerve stimulation (ES) (peroneal nerve-innervating tibialis anterior), (2) passive movement (PM) of the ankle joint, or (3) combined electrical stimulation and passive movement (Comb). The cortical excitability was assessed with transcranial magnetic stimulation determining motor evoked potentials (MEPs) in tibialis anterior before, immediately after and 30 min after the BCI training. Linear mixed regression models were used to assess the changes in MEPs. The three interventions led to a significant (p < 0.05) increase in MEP amplitudes immediately and 30 min after the training. The effect sizes of Comb paradigm were larger than ES and PM, although, these differences were not statistically significant (p > 0.05). These results indicate that the timing of movement imagery and afferent feedback is the main determinant of induced cortical plasticity whereas the specific type of feedback has a moderate impact. These findings can be important for the translation of such a BCI protocol to the clinical practice where by combining the BCI with the already available equipment cortical plasticity can be effectively induced. The findings in the current study need to be validated in stroke populations.
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Affiliation(s)
- Mads Jochumsen
- SMI, Department of Health Science and Technology, Aalborg University, Aalborg 9220, Denmark.
| | - Sylvain Cremoux
- LAMIH, UMR CNRS 8201, Université Polytechnique des Hauts de France, Valenciennes 59313, France.
| | - Lucien Robinault
- LAMIH, UMR CNRS 8201, Université Polytechnique des Hauts de France, Valenciennes 59313, France.
| | - Jimmy Lauber
- LAMIH, UMR CNRS 8201, Université Polytechnique des Hauts de France, Valenciennes 59313, France.
| | - Juan Carlos Arceo
- LAMIH, UMR CNRS 8201, Université Polytechnique des Hauts de France, Valenciennes 59313, France.
| | - Muhammad Samran Navid
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg 9000, Denmark.
- New Zealand College of Chiropractic, Auckland 1060, New Zealand.
| | - Rasmus Wiberg Nedergaard
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg 9000, Denmark.
- New Zealand College of Chiropractic, Auckland 1060, New Zealand.
| | - Usman Rashid
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand.
| | - Heidi Haavik
- New Zealand College of Chiropractic, Auckland 1060, New Zealand.
| | - Imran Khan Niazi
- SMI, Department of Health Science and Technology, Aalborg University, Aalborg 9220, Denmark.
- New Zealand College of Chiropractic, Auckland 1060, New Zealand.
- Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland 0627, New Zealand.
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