Restoration of reaching and grasping movements through brain-controlled muscle stimulation in a person with tetraplegia: a proof-of-concept demonstration

Abstract

SUMMARYBackgroundPeople with chronic tetraplegia due to high cervical spinal cord injury (SCI) can regain limb movements through coordinated electrical stimulation of peripheral muscles and nerves, known as Functional Electrical Stimulation (FES). Users typically command FES systems through other preserved, but limited and unrelated, volitional movements (e.g. facial muscle activity, head movements). We demonstrate an individual with traumatic high cervical SCI performing coordinated reaching and grasping movements using his own paralyzed arm and hand, reanimated through FES, and commanded using his own cortical signals through an intracortical brain-computer-interface (iBCI).MethodsThe study participant (53 years old, C4, ASIA A) received two intracortical microelectrode arrays in the hand area of motor cortex, and 36 percutaneous electrodes for electrically stimulating hand, elbow, and shoulder muscles. The participant used a motorized mobile arm support for gravitational assistance and to provide humeral ab/adduction under cortical control. We assessed the participant’s ability to cortically command his paralyzed arm to perform simple single-joint arm/hand movements and functionally meaningful multi-joint movements. We compared iBCI control of his paralyzed arm to that of a virtual 3D arm. This study is registered with ClinicalTrials.gov, NCT00912041.FindingsThe participant successfully cortically commanded single-joint and coordinated multi-joint arm movements for point-to-point target acquisitions (80% – 100% accuracy) using first a virtual arm, and second his own arm animated by FES. Using his paralyzed arm, the participant volitionally performed self-paced reaches to drink a mug of coffee (successfully completing 11 of 12 attempts within a single session) and feed himself.InterpretationThis is the first demonstration of a combined FES+iBCI neuroprosthesis for both reaching and grasping for people with SCI resulting in chronic tetraplegia, and represents a major advance, with a clear translational path, for clinically viable neuroprostheses for restoring reaching and grasping post-paralysis.

Review: Human Intracortical Recording and Neural Decoding for Brain–Computer Interfaces

“…For the purposes of BCI decoding in controlling assistive technologies, many researchers have focused on decoding neural activity from the motor cortex in both non-human primates (NHPs) [30]–[42] and early pilot clinical trials [11]–[15], [18]–[20], [23], [43]–[45]. …”

“…Many BCI systems are being developed to improve functional independence for individuals with severe motor limitations. Early pilot clinical trials are currently investigating the role of intracortical BCIs (iBCIs) for the purpose of restoring communication, such as typing on a computer screen [11]–[17] or as an effector for physical responses, such as controlling a robotic or prosthetic arm [18]–[21] or functional electrical stimulation systems [22], [23]. …”

Viral-mediated optogenetic stimulation of peripheral motor nerves in non-human primates

“…This approach, often referred to as Functional Electrical Stimulation (FES), was previously coupled to residual movements or muscle activity to control the electrical stimulation of paralyzed muscles [6,7]. More recently, intramuscular FES has been coupled with BMI control signals by several groups to produce brain-controlled modulation of native muscle activity and limb movements in both non-human primates (NHPs) [8,9] and human subjects [10]. While these studies demonstrate restoration of volitional control over previously paralyzed muscles and can convey a significant increase in independence to a patient, the control offered by these systems is far from ideal naturalistic control.…”

“…While these studies demonstrate restoration of volitional control over previously paralyzed muscles and can convey a significant increase in independence to a patient, the control offered by these systems is far from ideal naturalistic control. For example, in the study by Ajiboye et al [10], a C4-level SCI patient implanted with intracortical microelectrode arrays regained some volitional control over paralyzed arm muscles after pairing FES of those muscles with intracortical control signals. This scheme allowed the subject to reclaim certain daily functions such as feeding himself, but these movements were quite slow, taking several tens of seconds for tasks that most people would complete in a second or two.…”

Common Spatial Pattern Apresenta 18% a Mais De Acurácia Que Laplaciano Em Imagética Motora De Membro Superior

“…Nos últimos anos, as interfaces cérebro-máquina (BCI, do inglês Brain Computer Interface) do tipo não invasiva tem se mostrado uma área de pesquisa de grande potencial para a reabilitação de indivíduos, aliando conceitos de neurociência, reabilitação física e engenharia biomédica [1][2][3][4]. Este desenvolvimento é justificado pelos avanços dos sistemas BCI's no que diz respeito à usabilidade, transferência de informações e robustez das técnicas de processamento de sinal e controle [5].…”