Quadriplegia, Spinal Cord Injury, Tetraplegia C1-C4
Conditions
Brief summary
The goal of this clinical trial is to demonstrate control of digital devices through a brain implant in people with spinal cord injury. The main question it aims to answer is efficient, independent, BCI-based control over digital devices in settings of daily living of an individual with SCI. In this project an advanced generation fully implantable BCI system will be used, the Brain InterChange (BIC) from CorTec. Participants will be implanted with an electrode grid on the surface of the brain and an amplifier/transmitter on the skull, under the skin. Participation includes visits of researchers for recording and training at home, 1-3 times per week for one year. Extension of participation after one year is possible. If successful, the participant will be able to use the BCI at home independently, without the presence of a researcher.
Detailed description
Spinal Cord Injury (SCI) results in motor impairments in body parts innervated by the spinal cord below the site of the lesion. In addition to loss of leg movements, individuals with high cervical SCI experience significant impairments in arm and hand function (tetraplegia), impacting their access to digital devices, with obvious consequences for their ability to communicate, participate in society and the workforce, autonomously manage their life, and benefit from the entertainment options digital devices offer these days. Current assistive technologies (AT) for control over digital devices, such as voice control, eye-tracking, and head- or mouth-controlled devices, are often unintuitive, slow, limited in functionality, aesthetically unattractive, and they often interfere with regular movement or speech. An effective Brain-Computer Interface (BCI) would enable individuals with SCI to use movement-related neural signals to directly control digital devices, taking away the disadvantages of current AT. This would dramatically improve their quality of life. The Brain InterChange from CorTec is an active implantable medical device for measurement of neuronal activity and electrical stimulation of the human nervous system, comprising an internal and an external unit. The internal unit consists of a small high-density ECoG grid with 32 contacts placed subdurally and a connected implantable amplifier/transmitter device that is placed subcutaneously. The external unit comprises a headpiece, for power transmission to the internal unit, a communication unit, that receives the data transmitted from the internal unit and controls the power transmission, and a USB cable, that connects the communication unit to the computer that has software to process and translate the brain data to a means of digital device control for SCI patients with custom in-house software developed during this study. The BCI system also allows to provide users with somatosensory feedback about their motor attempts (in addition to the visual feedback), by delivering electrocortical stimulation (ECS) to the somatosensory regions of the brain. As such, the aim is to generate a more natural relation between intent (movement attempt of a body part) and effect (sensation in the same body part), which is expected to lead to fast training and accurate BCI performance.
Interventions
Implant electrodes and amplifier/transmitter and use, through amplifier and decoding, for control of BCI
Sponsors
UMC Utrecht
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* Clinical diagnosis of SCI at the cervical level C4 or higher (C1-C4) * Complete or incomplete tetraplegia (quadriplegia) or tetraparesis (quadriparesis), i.e., level A or B at the American Spinal Injury Association (ASIA) Impairment Scale * Meeting surgical safety criteria, including surgical clearance by the study physicians * Meeting (neuro)psychological evaluation criteria * Ability to communicate reliably, via speech or other means * Willingness and ability to provide informed consent. * Lives within reasonable distance from UMC Utrecht * Participant consents to the study and still wishes to participate at the time of the study. * Vision and hearing largely intact. * For candidates who are not currently receiving invasive ventilation, and who have current respiratory problems (e.g., at night), there should be a clear and confirmed desire to proceed with tracheostomy ventilation whenever that would become necessary.
Exclusion criteria
* Having a spinal cord injury with a degenerative or progressive etiology. * Having evident swallowing problems. * Having a significant current or recent anxiety disorder or depression or cognitive impairment that would interfere with obtaining informed consent or fully participating in study activities. * Medical conditions contraindicating surgery of a chronically implanted device or that could interfere with study participation (for example active infections, unexplained fever, existing scalp lesions or skin breakdown, osteomyelitis, hepatitis, any autoimmune disease/disorder, epilepsy, skin disorders causing excessive skin sloughing or poor wound healing, cranioplasty, significant cardiovascular, metabolic, or renal impairments, chronic oral or intravenous use of steroids or immunosuppressive therapy, active cancer within the past year or requires chemotherapy, uncontrolled autonomic dysreflexia within the past 3 months, hydrocephalus with or without an implanted ventricular shunt or a medical contraindication to stop anti-coagulant medications during surgery, or a catabolic state, or strong and frequent spasms) * Presence of pre-surgical findings in anatomical, functional, and/or vascular neuroimaging that makes achieving implant locations too challenging or incompatible with desired risk levels. * Inability to undergo MRI for pre-implantation evaluation, for example due to the presence of implanted devices that are incompatible with MRI, which may include pacemakers, cardiac defibrillators, spinal cord or vagal nerve stimulators, deep brain stimulators, and cochlear implants or devices that deliver diaphragm pacing. * Anticipated need for MRI after implantation of the Brain InterChange system.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Effectiveness of BCI Control: Accuracy | 1 year | Accuracy: \>80% sensitivity (true positive rate) for 1-command control; 80% classification accuracy (distinguishing between multiple classes) for multi-command control; and 80% classification accuracy and the correlation between the intended and actual response for multi-command continuous control |
| Efficiency of BCI control: Speed | 1 year | number of accurate selections made per minute |
| Efficiency of BCI control: Subjective Workload - Visual Analogue Scale | 1 year | Subjective Workload: Visual Analogue Scale Continuous scale: Little to no effort (0) - Much effort (5). Lower numbers are better. |
| Efficiency of BCI control: Subjective Workload - National Aeronautics and Space Administration-Task Load Index | 1 year | Subjective Workload: National Aeronautics and Space Administration-Task Load Index Scale: 21 point Likert-type scale. Lower numbers are better. |
| User satisfaction Quebec User Evaluation of Satisfaction with assistive Technology (QUEST) | 1 year | User Satisfaction: Quebec User Evaluation of Satisfaction with assistive Technology version 2.0. Likert-type scale: Extremely dissatisfied - Dissatisfied - Slightly satisfied - Satisfied - Extremely satisfied. Extremely Satisfied is the best result. |
| user satisfaction Psychosocial impact of assistive devices scale (PIADS) | 1 year | User Satisfaction: Psychosocial impact of assistive devices scale. Likert-type scale -3, -2, -1, 0, 1, 2, 3. 3 is best result. |
| Stability of BCI performance: impedance | 1 year | Longitudinally follow the electrode impedance (in Ω), to assess their stability throughout the day and across the weeks and months after implantation. |
| Stability of BCI performance: signal dynamics | 1 year | Longitudinally follow the raw signal dynamics (in µV) of neural signals, to assess their stability throughout the day and across the weeks and months after implantation. |
| Stability of BCI performance: task-related modulation | 1 year | Longitudinally follow the task-related modulation in power (in µV), to assess their stability throughout the day and across the weeks and months after implantation. |
| Effects of somatosensory feedback on BCI Training and Performance: accuracy | 1 year | Compare BCI control accuracy (in %), including variability and improvement therein before and after applying somatosensory feedback through electrocortical stimulation of the somatosensory cortex |
| Effects of somatosensory feedback on BCI Training and Performance: neural signals | 1 year | Compare neural signal changes (in µV) in the sensorimotor areas before and after applying somatosensory feedback through electrocortical stimulation of the somatosensory cortex |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Assess device specifications for future, larger-scale, application of HD ECoG-BCIs | 1 year | qualitative description on device specifications and experimental parameters, such as the specific decoder settings, for future, larger scale, application of HD ECoG-BCIs |
| Validation of software for independent home-use of advanced BCIs | 1 year | Validation: Questionnaire to evaluate user satisfaction and ease of use of the home use software. Likert-type scale: fully disagree - disagree - neither agree or disagree - agree - fully agree - not applicable. Fully agree is the best result. |
Countries
Netherlands
Contacts
CONTACTMariska J Vansteensel, PhD
CONTACTErik J Aarnoutse, PhD
PRINCIPAL_INVESTIGATORNick F Ramsey, PhD
UMC Utrecht
Outcome results
None listed