19 results on '"Armand Hoxha"'
Search Results
2. EEG-Based Spectral Analysis Showing Brainwave Changes Related to Modulating Progressive Fatigue During a Prolonged Intermittent Motor Task
- Author
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Easter S. Suviseshamuthu, Vikram Shenoy Handiru, Didier Allexandre, Armand Hoxha, Soha Saleh, and Guang H. Yue
- Subjects
EEG ,fatigue ,maximum voluntary contraction ,motor cortex ,power spectral density ,submaximal muscle contraction ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Repeatedly performing a submaximal motor task for a prolonged period of time leads to muscle fatigue comprising a central and peripheral component, which demands a gradually increasing effort. However, the brain contribution to the enhancement of effort to cope with progressing fatigue lacks a complete understanding. The intermittent motor tasks (IMTs) closely resemble many activities of daily living (ADL), thus remaining physiologically relevant to study fatigue. The scope of this study is therefore to investigate the EEG-based brain activation patterns in healthy subjects performing IMT until self-perceived exhaustion. Fourteen participants (median age 51.5 years; age range 26−72 years; 6 males) repeated elbow flexion contractions at 40% maximum voluntary contraction by following visual cues displayed on an oscilloscope screen until subjective exhaustion. Each contraction lasted ≈5 s with a 2-s rest between trials. The force, EEG, and surface EMG (from elbow joint muscles) data were simultaneously collected. After preprocessing, we selected a subset of trials at the beginning, middle, and end of the study session representing brain activities germane to mild, moderate, and severe fatigue conditions, respectively, to compare and contrast the changes in the EEG time-frequency (TF) characteristics across the conditions. The outcome of channel- and source-level TF analyses reveals that the theta, alpha, and beta power spectral densities vary in proportion to fatigue levels in cortical motor areas. We observed a statistically significant change in the band-specific spectral power in relation to the graded fatigue from both the steady- and post-contraction EEG data. The findings would enhance our understanding on the etiology and physiology of voluntary motor-action-related fatigue and provide pointers to counteract the perception of muscle weakness and lack of motor endurance associated with ADL. The study outcome would help rationalize why certain patients experience exacerbated fatigue while carrying out mundane tasks, evaluate how clinical conditions such as neurological disorders and cancer treatment alter neural mechanisms underlying fatigue in future studies, and develop therapeutic strategies for restoring the patients' ability to participate in ADL by mitigating the central and muscle fatigue.
- Published
- 2022
- Full Text
- View/download PDF
3. The Role of Premotor Areas in Dual Tasking in Healthy Controls and Persons With Multiple Sclerosis: An fNIRS Imaging Study
- Author
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Soha Saleh, Brian M. Sandroff, Tyler Vitiello, Oyindamola Owoeye, Armand Hoxha, Patrick Hake, Yael Goverover, Glenn Wylie, Guang Yue, and John DeLuca
- Subjects
multiple sclerosis ,dual-task cost ,fNIRS ,premotor cortex ,SMA ,neuropsychology measures ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Persons with multiple sclerosis (pwMS) experience declines in physical and cognitive abilities and are challenged by dual-tasks. Dual-tasking causes a drop in performance, or what is known as dual-task cost (DTC). This study examined DTC of walking speed (WS) and cognitive performance (CP) in pwMS and healthy controls (HCs) and the effect of dual-tasking on cortical activation of bilateral premotor cortices (PMC) and bilateral supplementary motor area (SMA). Fourteen pwMS and 14 HCs performed three experimental tasks: (1) single cognitive task while standing (SingCog); (2) single walking task (SingWalk); and (3) dual-task (DualT) that included concurrent performance of the SingCog and SingWalk. Six trials were collected for each condition and included measures of cortical activation, WS and CP. WS of pwMS was significantly lower than HC, but neuropsychological (NP) measures were not significantly different. pwMS and HC groups had similar DTC of WS, while DTC of CP was only significant in the MS group; processing speed and visual memory predicted 55% of this DTC. DualT vs. SingWalk recruited more right-PMC activation only in HCs and was associated with better processing speed. DualT vs. SingCog recruited more right-PMC activation and bilateral-SMA activation in both HC and pwMS. Lower baseline WS and worse processing speed measures in pwMS predicted higher recruitment of right-SMA (rSMA) activation suggesting maladaptive recruitment. Lack of significant difference in NP measures between groups does not rule out the influence of cognitive factors on dual-tasking performance and cortical activations in pwMS, which might have a negative impact on quality of life.
- Published
- 2018
- Full Text
- View/download PDF
4. Corticomuscular Connectivity during Walking in Able Bodied and Individuals with Incomplete Spinal Cord Injury.
- Author
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Soha Saleh, Michael Glassen, Kamyar Momeni, Manikandan Ravi, Akhil Bheemreddy, Armand Hoxha, Erica Garbarini, Guang H. Yue, and Gail F. Forrest
- Published
- 2022
- Full Text
- View/download PDF
5. Altered Modulation of the Movement-Related Beta Desynchronization with Force in Stroke - a Pilot Study.
- Author
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Didier Allexandre, Vikram Shenoy Handiru, Armand Hoxha, Danit Mark, Suviseshamuthu Easter Selvan, and Guang H. Yue
- Published
- 2021
- Full Text
- View/download PDF
6. An Automated Workflow for the Electric Field Modeling of High-definition Transcranial Direct Current Stimulation (HD-tDCS) in Chronic Stroke with Lesions.
- Author
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Vikram Shenoy Handiru, Danit Mark, Armand Hoxha, and Didier Allexandre
- Published
- 2021
- Full Text
- View/download PDF
7. Relationship between DTI Brain Connectivity and Functional Performance in Individuals with Traumatic Brain Injury*.
- Author
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Alaleh Alivar, Michael Glassen, Armand Hoxha, Didier Allexandre, Guang H. Yue, and Soha Saleh
- Published
- 2020
- Full Text
- View/download PDF
8. Difference in Cortical Modulation of Walking between Persons with Multiple Sclerosis and Healthy Controls: An EEG pilot study.
- Author
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Armand Hoxha, Michael Glassen, John DeLuca, Marek A. Kwasnica, Guang H. Yue, and Soha Saleh
- Published
- 2019
- Full Text
- View/download PDF
9. Altered Cortical and Postural Response to Balance Perturbation in Traumatic Brain Injury - An EEG Pilot Study.
- Author
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Didier Allexandre, Armand Hoxha, Vikram Shenoy Handiru, Soha Saleh, S. Easter Selvan, and Guang H. Yue
- Published
- 2019
- Full Text
- View/download PDF
10. Supra-Spinal Modulation Of Walking In Healthy Individuals And Persons With Multiple Sclerosis: A fNIRS Mobile Imaging Study.
- Author
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Brian M. Sandroff, Oyindamola Owoeye, Tyler Vitiello, Armand Hoxha, Guang H. Yue, and John DeLuca
- Published
- 2018
- Full Text
- View/download PDF
11. Graph‐theoretical analysis of EEG functional connectivity during balance perturbation in traumatic brain injury: A pilot study
- Author
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Easter S. Suviseshamuthu, Didier Allexandre, Guang H. Yue, Armand Hoxha, Soha Saleh, Alaleh Alivar, and Vikram Shenoy Handiru
- Subjects
Adult ,Male ,medicine.medical_specialty ,Traumatic brain injury ,graph theory ,Pilot Projects ,Electroencephalography ,postural control ,White matter ,Physical medicine and rehabilitation ,Center of pressure (terrestrial locomotion) ,Brain Injuries, Traumatic ,medicine ,Connectome ,Humans ,Radiology, Nuclear Medicine and imaging ,Postural Balance ,Research Articles ,Balance (ability) ,Neural correlates of consciousness ,Radiological and Ultrasound Technology ,Functional integration (neurobiology) ,medicine.diagnostic_test ,traumatic brain injury ,balance perturbation ,functional connectivity ,Neurophysiology ,Middle Aged ,medicine.disease ,Brain Waves ,White Matter ,EEG source localization ,medicine.anatomical_structure ,Diffusion Tensor Imaging ,Neurology ,Berg Balance Scale ,Female ,Neurology (clinical) ,Anatomy ,Psychology ,Diffusion MRI ,Research Article - Abstract
Traumatic brain injury (TBI) often results in balance impairment, increasing the risk of falls, and the chances of further injuries. However, the underlying neural mechanisms of postural control after TBI are not well understood. To this end, we conducted a pilot study to explore the neural mechanisms of unpredictable balance perturbations in 17 chronic TBI participants and 15 matched healthy controls (HC) using the EEG, MRI, and diffusion tensor imaging (DTI) data. As quantitative measures of the functional integration and segregation of the brain networks during the postural task, we computed the global graph‐theoretic network measures (global efficiency and modularity) of brain functional connectivity derived from source‐space EEG in different frequency bands. We observed that the TBI group showed a lower balance performance as measured by the center of pressure displacement during the task, and the Berg Balance Scale (BBS). They also showed reduced brain activation and connectivity during the balance task. Furthermore, the decrease in brain network segregation in alpha‐band from baseline to task was smaller in TBI than HC. The DTI findings revealed widespread structural damage. In terms of the neural correlates, we observed a distinct role played by different frequency bands: theta‐band modularity during the task was negatively correlated with the BBS in the TBI group; lower beta‐band network connectivity was associated with the reduction in white matter structural integrity. Our future studies will focus on how postural training will modulate the functional brain networks in TBI., EEG connectivity graph measures were studied in traumatic brain injury (TBI) during the balance perturbation task. TBI group showed altered brain activation and connectivity during the balance task. Graph‐theoretic measures showed that the task modulation of brain network segregation in alpha‐band was reduced in TBI and the network segregation in theta‐band was associated with postural instability in TBI.
- Published
- 2021
12. Altered Modulation of the Movement-Related Beta Desynchronization with Force in Stroke – a Pilot Study
- Author
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Didier, Allexandre, Vikram Shenoy, Handiru, Armand, Hoxha, Danit, Mark, Easter S, Suviseshamuthu, and Guang H, Yue
- Subjects
Stroke ,Upper Extremity ,Motor Cortex ,Stroke Rehabilitation ,Humans ,Pilot Projects - Abstract
Conventional therapy improves motor recovery after stroke. However, 50% of stroke survivors still suffer from a significant level of long-term upper extremity impairment. Identifying a specific biomarker whose magnitude scales with the level of force could help in the development of more effective, novel, highly targeted rehabilitation therapies such as brain stimulation or neurofeedback. Four chronic stroke participants were enrolled in this pilot study to find such a neural marker using an Independent Component Analysis (ICA)-based source analysis approach, and investigate how it has been affected by the injury. Beta band desynchronization in the ipsilesional primary motor cortex was found to be most robustly scaling with force. This activity modulation with force was found to be significantly reduced, and to plateau at higher force than that of the contralesional (unaffected) side. A rehabilitation therapy that would target such a neuromarker could have the potential to strengthen the brain-to-muscle drive and improve motor learning and recovery.Clinical Relevance- This study identifies a neural marker that scales with motor output and shows how this modulation has been affected by stroke.
- Published
- 2021
13. EEG-Based Spectral Analysis Showing Brainwave Changes Related to Modulating Progressive Fatigue During a Prolonged Intermittent Motor Task
- Author
-
Easter S. Suviseshamuthu, Armand Hoxha, Guang H. Yue, Didier Allexandre, Soha Saleh, and Vikram Shenoy Handiru
- Subjects
medicine.medical_specialty ,Activities of daily living ,medicine.diagnostic_test ,Muscle fatigue ,business.industry ,Elbow ,Alpha (ethology) ,Muscle weakness ,Electroencephalography ,Peripheral ,medicine.anatomical_structure ,Physical medicine and rehabilitation ,medicine ,medicine.symptom ,business ,Sensory cue - Abstract
Repeatedly performing a submaximal motor task for a prolonged period of time leads to muscle fatigue manifested by its reduced capacity to generate force or power. Fatigue resulted from voluntary muscle contractions comprises a central and peripheral component, which demands a gradually increasing effort to perform the task as time elapses. However, we still lack a complete understanding of brain contribution to the enhancement of effort to cope with progressing fatigue because of repeated submaximal muscle contractions. The knowledge of how muscle fatigue modulates brain activities in a healthy population will help rationalize why certain patients experience exacerbated fatigue while carrying out mundane tasks. The intermittent motor tasks closely resemble many activities of daily living (ADL), thus remaining physiologically relevant to study fatigue. The scope of this study is therefore to investigate the EEG-based brain activation patterns in healthy subjects performing intermittent submaximal muscle contractions until self-perceived exhaustion. Fourteen participants (median age 51.5 years; age range 26-72 years; 5 males) repeated elbow flexion contractions at 40% maximum voluntary contraction by following visual cues displayed on an oscilloscope screen until subjective exhaustion. Each contraction lasted ~5 s with a 2-s rest between trials. The force, EEG, and surface EMG (from elbow joint muscles) data were simultaneously collected. After preprocessing, we selected a subset of trials at the beginning, middle, and end of the study session representing brain activities germane to mild, moderate, and severe fatigue conditions, respectively, to compare and contrast the changes in the EEG time-frequency (TF) characteristics across the conditions. The TF analyses were conducted both at the channel and source level. The outcome of the channel- and source-level analyses reveal that the theta, alpha, and beta power spectral densities (PSDs) vary in proportion to fatigue levels in cortical motor areas. Importantly, the pairwise PSD differences between the fatigue conditions survived the statistical inferential tests with a p-value threshold of 0.05. We observed a statistically significant change in the band-specific spectral power in relation to the graded fatigue from both the steady- and post- contraction EEG data. The findings would enhance our understanding of the etiology and physiology of voluntary motor action-related fatigue and provide pointers to counteract the perception of muscle weakness and lack of motor endurance associated with ADL. The study outcome would help evaluate how clinical conditions such as neurological disorders and cancer treatment alter neural mechanisms underlying fatigue in future studies and develop therapeutic strategies for restoring the patients9 ability to participate in ADL by mitigating central and muscle fatigue.
- Published
- 2021
14. Relationship between DTI Brain Connectivity and Functional Performance in Individuals with Traumatic Brain Injury
- Author
-
Didier Allexandre, Armand Hoxha, Guang H. Yue, Soha Saleh, Alaleh Alivar, and Michael Glassen
- Subjects
Moderate to severe ,medicine.medical_specialty ,Task switching ,Trail making ,Traumatic brain injury ,Maximum voluntary contraction ,05 social sciences ,Brain ,Cognition ,Regression analysis ,Physical Functional Performance ,medicine.disease ,Magnetic Resonance Imaging ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Brain Injuries, Traumatic ,medicine ,Humans ,Cingulum (brain) ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Nerve Net ,Psychology ,030217 neurology & neurosurgery - Abstract
this study examines the relationship between brain structural connectivity, and physical and cognitive performances in individuals with Traumatic Brain Injury (TBI). Nine moderate to severe TBI participants were included in the study, and regression analysis was performed to explore if DTI connectivity of 16 regions of interest can predict individuals' : 1) Maximum Voluntary Contraction (MVC), 2) time component of Wolf Motor Function Test (WMFT), 3) Reaction Time (RT) during bimanual force matching task, 4) Performance Error Measurement (PEM) during bimanual force matching task, and 5) cognitive assessment of task switching using Trail Making (TM) test. Results showed that slower WMFT, PEM, and TM can be predicted by weaker cerebrospinal tract connectivity. Higher Caudate connectivity predicted higher WMFT and slower RT, and higher right Cingulum predicted faster TM. Current results suggest that measures of cognitive-motor interference may be better indicators of functional performance than single cognitive and motor performance tests.
- Published
- 2020
15. Altered Cortical and Postural Response to Balance Perturbation in Traumatic Brain Injury – An EEG Pilot Study
- Author
-
Vikram Shenoy Handiru, Armand Hoxha, Guang H. Yue, Soha Saleh, Didier Allexandre, and S. Easter Selvan
- Subjects
medicine.medical_specialty ,Traumatic brain injury ,Posture ,Pilot Projects ,Electroencephalography ,050105 experimental psychology ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Center of pressure (terrestrial locomotion) ,Group differences ,Brain Injuries, Traumatic ,medicine ,Humans ,0501 psychology and cognitive sciences ,Muscle activity ,Evoked potential ,Muscle, Skeletal ,Postural Balance ,medicine.diagnostic_test ,Electromyography ,business.industry ,05 social sciences ,medicine.disease ,Berg Balance Scale ,Balance perturbation ,business ,030217 neurology & neurosurgery - Abstract
30-60% of traumatic brain injury (TBI) patients suffer from long-term balance deficit. Even though motor preparation and execution are altered and slowed in TBI, their relative contribution and importance to posture instability remain poorly understood. This study investigates the impaired cortical dynamics and neuromuscular response in TBI in response to balance perturbation and its relation to balance deficit. 12 TBI and 6 healthy control (HC) participants took the Berg Balance Scale (BBS) test and participated in a balance perturbation task where they were subjected to random anterior/posterior translation, while brain (EEG), muscle (EMG) activities, and center of pressure (COP) were continuously recorded. Using independent component analysis (ICA), the component most responsible for the N1 component of the perturbation evoked potential (PEP) was selected and its amplitude and latency were extracted. Balance task performance was measured by computing the COP displacement during the task. TBI had a significantly lower BBS, larger COP displacement and lower N1 amplitude compared to the HC group. No group differences was found for N1 latency and muscle activity onset delay to the perturbation. BBS was correlated with the COP displacement and N1 amplitude, and COP displacement was correlated with N1 latency. TBI balance deficit may be associated with more impaired than delayed cortical response to balance perturbation.
- Published
- 2019
16. Difference in Cortical Modulation of Walking between Persons with Multiple Sclerosis and Healthy Controls: An EEG pilot study
- Author
-
Marek A. Kwasnica, Armand Hoxha, Soha Saleh, John DeLuca, Guang H. Yue, and Michael Glassen
- Subjects
Male ,medicine.medical_specialty ,Multiple Sclerosis ,Posterior parietal cortex ,Pilot Projects ,Walking ,Electroencephalography ,Gyrus Cinguli ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Parietal Lobe ,Cortex (anatomy) ,medicine ,Humans ,Gait ,030304 developmental biology ,0303 health sciences ,medicine.diagnostic_test ,business.industry ,Multiple sclerosis ,Middle Aged ,medicine.disease ,Broca Area ,Preferred walking speed ,medicine.anatomical_structure ,Case-Control Studies ,Posterior cingulate ,Female ,business ,human activities ,030217 neurology & neurosurgery ,Pars opercularis - Abstract
The overall goal of this study is to investigate the role of parietal cortex in the control of walking in persons with Multiple Sclerosis (pwMS). We examined within-brain connectivity and cortico-muscular connectivity as pwMS and healthy control (HC) participants walked on an instrumented treadmill. Cortical activity was collected using EEG, muscle activity was collected using wireless EMG modules, and gait data were obtained by using the instrumented treadmill. Results show significant activation of sensorimotor and posterior parietal cortex during walking in both groups. Connectivity between parietal (posterior cingulate cortex PCC) and premotor regions (pars opercularis), and between PCC and contralateral muscles were higher in the healthy control group. Higher connectivity correlated with higher walking speed.
- Published
- 2019
17. Augmented Attention During Physical Training Improves Motor Performance in Individuals With Traumatic Brain Injury
- Author
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Armand Hoxha, Guang H. Yue, Michael Glassen, Soha Saleh, and Alaleh Alivar
- Subjects
medicine.medical_specialty ,Physical medicine and rehabilitation ,Traumatic brain injury ,business.industry ,Rehabilitation ,medicine ,Training (meteorology) ,Physical Therapy, Sports Therapy and Rehabilitation ,medicine.disease ,business - Published
- 2020
18. Supra-Spinal Modulation Of Walking In Healthy Individuals And Persons With Multiple Sclerosis: A fNIRS Mobile Imaging Study
- Author
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Soha Saleh, Brian M. Sandroff, Oyindamola Owoeye, Tyler Vitiello, Armand Hoxha, Guang Yue, and John DeLuca
- Subjects
Nervous system ,030506 rehabilitation ,medicine.medical_specialty ,Multiple Sclerosis ,Activities of daily living ,Population ,Walking ,Electroencephalography ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Activities of Daily Living ,medicine ,Humans ,education ,education.field_of_study ,Spectroscopy, Near-Infrared ,medicine.diagnostic_test ,Multiple sclerosis ,Motor Cortex ,Cognition ,medicine.disease ,Gait ,medicine.anatomical_structure ,0305 other medical science ,030217 neurology & neurosurgery ,Motor cortex - Abstract
Multiple sclerosis (MS) is one of the neurodegenerative diseases that damage the nervous system and inflicts cognitive and motor deficits. In motor domain, MS mainly causes slower gait resulting in challenges in activities of daily living. Premotor cortices are affected by MS, where several imaging studies have reported re-organization in the activity and connectivity of these regions. Recent advancements in mobile imaging technologies and signal processing techniques have made it possible to study supraspinal modulation of walking in able-bodied individuals and persons with injuries or neurological disorders. Functional near-infrared spectroscopy (fNIRS), for example, was used in studying dual-tasking in MS population. In the current study, we used fNIRS to record activities of premotor and supplementary motor areas in MS and healthy populations during standing and walking. Fourteen healthy controls and 14 persons with MS were tested during overground walking. Results show higher right premotor cortex activities compared with left premotor and bilateral supplementary motor areas in the MS group. In the healthy control group, activity was higher during walking in all the four studied brain regions. These results confirm the role of the premotor cortices in movement planning and in modulating walking activities; they also confirm that individuals with mild MS have a similar premotor control strategy as healthy controls while performing the same physical task.
- Published
- 2018
19. Cortical control of walking with and without powered exoskeleton assistance: An EEG pilot study
- Author
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Kamyar Momeni, Gail F. Forrest, Syed R. Husain, Arvind Ramanujam, Armand Hoxha, Didier Allexandre, Guang H. Yue, and Soha Saleh
- Subjects
medicine.medical_specialty ,medicine.diagnostic_test ,Brain activity and meditation ,business.industry ,Powered exoskeleton ,Electroencephalography ,medicine.disease ,Gait ,Exoskeleton ,Physical medicine and rehabilitation ,Neuroimaging ,Cortical control ,medicine ,business ,human activities ,Spinal cord injury - Abstract
Brain activity and cortico-muscular connectivity vary during walking in correlation with different phases of the walking cycle; a mechanism that may be disrupted in individuals with incomplete spinal cord injury (iSCI). This exploratory study aims to detect brain signals during walking and determine the effect of exoskeleton-walking robot (EWR) assistance on brain activity using mobile brain imaging techniques (scalp EEG). Acquiring such knowledge in SCI is critical to the development of effective rehabilitation interventions aimed at maximizing gait function recovery. EEG data were collected from 1 able-bodied (AB) and 1 iSCI participant during walking and with and without EWR assistance (using both “Max Assist” and “Free Limb” settings). Results showed our ability to record EEG data and to measure cortico-muscular coherence correlating with walking task and to identify differences in cortical connectivity during different types of EWR assistance.
- Published
- 2017
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