Non-invasive BCI-controlled Assistive Devices

NCT ID: NCT05183152

Last Updated: 2025-04-02

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 100 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-06-16
• Study Completion Date: 2025-12-30

Brief Summary

Injuries affecting the central nervous system may disrupt the cortical pathways to muscles causing loss of motor control. Nevertheless, the brain still exhibits sensorimotor rhythms (SMRs) during movement intents or motor imagery (MI), which is the mental rehearsal of the kinesthetics of a movement without actually performing it. Brain-computer interfaces (BCIs) can decode SMRs to control assistive devices and promote functional recovery. Despite rapid advancements in non-invasive BCI systems based on EEG, two persistent challenges remain: First, the instability of SMR patterns due to the non-stationarity of neural signals, which may significantly degrade BCI performance over days and hamper the effectiveness of BCI-based rehabilitation. Second, differentiating MI patterns corresponding to fine hand movements of the same limb is still difficult due to the low spatial resolution of EEG. To address the first challenge, subjects usually learn to elicit reliable SMR and improve BCI control through longitudinal training, so a fundamental question is how to accelerate subject training building upon the SMR neurophysiology. In this study, the investigators hypothesize that conditioning the brain with transcutaneous electrical spinal stimulation, which reportedly induces cortical inhibition, would constrain the neural dynamics and promote focal and strong SMR modulations in subsequent MI-based BCI training sessions - leading to accelerated BCI training. To address the second challenge, the investigators hypothesize that neuromuscular electrical stimulation (NMES) applied contingent to the voluntary activation of the primary motor cortex through MI can help differentiate patterns of activity associated with different hand movements of the same limb by consistently recruiting the separate neural pathways associated with each of the movements within a closed-loop BCI setup. The investigators study the neuroplastic changes associated with training with the two stimulation modalities.

Conditions

Motor Disorders; Healthy; Spinal Cord Injuries; Muscular Diseases; Motor Neuron Disease; Stroke; Traumatic Brain Injury; Movement Disorders; Multiple Sclerosis

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: FACTORIAL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

TESS BCI - Standard MI Task

Transcutaneous Electrical Spinal Stimulation (TESS) is applied for 20 minutes prior to BCI training sessions. Following TESS, BCI training is performed with visual feedback contingent to motor imagery as detected by a closed-loop BCI.

Group Type: EXPERIMENTAL

Visual Feedback

Intervention Type: DEVICE

Electroencephalography (EEG) - recorded from subjects as they perform cued motor imagery (MI) tasks - are classified in real-time using a subject-specific BCI decoder,. The output classification probability of the decoder is accumulated using exponential smoothing and translated into continuous visual feedback by means of a bar - on a computer screen - that moves to the right or left in response to classification of one or the other MI task.

TESS

Intervention Type: DEVICE

Transcutaneous Electrical Spinal Stimulation (TESS) is applied over the C5-C6 spinal segment for 20 minutes at 30Hz with 5kHz carrier frequency.

Visual BCI - Standard MI Task

Conventional BCI training is performed with visual feedback contingent to the imagination of right versus left hand movements as detected by a closed-loop BCI.

Group Type: ACTIVE_COMPARATOR

Visual Feedback

Intervention Type: DEVICE

Electroencephalography (EEG) - recorded from subjects as they perform cued motor imagery (MI) tasks - are classified in real-time using a subject-specific BCI decoder,. The output classification probability of the decoder is accumulated using exponential smoothing and translated into continuous visual feedback by means of a bar - on a computer screen - that moves to the right or left in response to classification of one or the other MI task.

NMES BCI - Difficult MI Task

BCI training is performed with NMES instead of Visual feedback. NMES is delivered over the flexors/extensors of the forearm contingent to the imagination of same-hand wrist and fingers flexion versus extension as detected by a closed-loop BCI.

Group Type: EXPERIMENTAL

NMES Feedback

Intervention Type: DEVICE

Electroencephalography (EEG) signals will be recorded from subjects as they perform cued tasks for flexing/extending their non-dominant hand. The signals will be processed and classified in real-time using machine learning algorithms to trigger electrical stimulation on the flexors/extensors of the targeted arm contingent to the detection of a subject-specific flexion/extension EEG patterns.

Visual BCI - Difficult MI Task

Conventional BCI training is performed with visual feedback contingent to the imagination of same-hand wrist and fingers flexion versus extension as detected by a closed-loop BCI.

Group Type: ACTIVE_COMPARATOR

Visual Feedback

Intervention Type: DEVICE

Electroencephalography (EEG) - recorded from subjects as they perform cued motor imagery (MI) tasks - are classified in real-time using a subject-specific BCI decoder,. The output classification probability of the decoder is accumulated using exponential smoothing and translated into continuous visual feedback by means of a bar - on a computer screen - that moves to the right or left in response to classification of one or the other MI task.

Interventions

NMES Feedback

Electroencephalography (EEG) signals will be recorded from subjects as they perform cued tasks for flexing/extending their non-dominant hand. The signals will be processed and classified in real-time using machine learning algorithms to trigger electrical stimulation on the flexors/extensors of the targeted arm contingent to the detection of a subject-specific flexion/extension EEG patterns.

Intervention Type: DEVICE

Visual Feedback

Electroencephalography (EEG) - recorded from subjects as they perform cued motor imagery (MI) tasks - are classified in real-time using a subject-specific BCI decoder,. The output classification probability of the decoder is accumulated using exponential smoothing and translated into continuous visual feedback by means of a bar - on a computer screen - that moves to the right or left in response to classification of one or the other MI task.

Intervention Type: DEVICE

TESS

Transcutaneous Electrical Spinal Stimulation (TESS) is applied over the C5-C6 spinal segment for 20 minutes at 30Hz with 5kHz carrier frequency.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

1. Able-bodied participants:

• good general health
• normal or corrected vision
• no history of neurological/psychiatric disease
• ability to read and understand English (Research Personnel do not speak Spanish)

2. Subjects with motor disabilities

• motor deficits due to: unilateral and bilateral stroke / spinal cord injury / motor neuron diseases (i.e. amyotrophic lateral sclerosis, spino-cerebellar ataxia, multiple sclerosis) / muscular diseases (i.e. myopathy) / traumatic or neurological pain / movement disorders (i.e. cerebral palsy) / orthopedic / traumatic brain injury / brain tumors
• normal or corrected vision
• ability to read and understand English
• ability to provide informed consent

Exclusion Criteria

1. Subjects with motor disabilities

• short attentional spans or cognitive deficits that prevent the subject from concentrating during the whole experimental session
• heavy medication affecting the central nervous system (including vigilance)
• concomitant serious illness (e.g., metabolic disorders)

2. All participants

• factors hindering EEG/EMG acquisition and the delivery of non-invasive electrical stimulation (e.g., skin infection, wounds, dermatitis, metal implants under electrodes)
• criteria identified in safety guidelines for MRI and TMS, in particular metallic implants

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Texas at Austin

OTHER

Sponsor Role: lead

Responsible Party

Jose del R. Millan

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Jose del R. Millan, PhD

Role: PRINCIPAL_INVESTIGATOR

The University of Texas at Austin

Locations

The University of Texas at Austin

Austin, Texas, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Jose del R. Millan, PhD

Role: CONTACT

jose.millan@austin.utexas.edu

512-232-8111

Hussein Alawieh

Role: CONTACT

hussein@utexas.edu

512-373-0535

Facility Contacts

Jose del R. Millan, PhD

Role: primary

jose.millan@austin.utexas.edu

512-232-8111

Hussein Alawieh

Role: backup

hussein@utexas.edu

5123730535

Other Identifiers

2020030073

Identifier Type: -

Identifier Source: org_study_id