Selective neural electrical stimulation restores hand and forearm movements in individuals with complete tetraplegia (original) (raw)
Related papers
2019
BackgroundFunctional Electrical Stimulation (FES) is used for decades in rehabilitation centers. For patients with a spinal cord injury (SCI), FES can prevent muscular atrophy, reduce spasticity and/or restore limb movements. To this last aim, FES external devices can be used, but elicit imprecise movements. FES implanted devices used neuromuscular stimulation and required implantation of one electrode for each site (muscle) to stimulate, an heavy surgical procedure and 10 times more electrical charges than nerve stimulation. Moreover, complications related to the numerous implanted components could appear over time. The purpose of this work is to evaluate whether a multi-contact nerve cuff electrode can selectively activate forearm and hand muscles and restore functional movements in patient with a complete tetraplegia.MethodsA 12-contacts cuff electrode was designed to selectively activate, without damage it, multi fascicular peripheral nerve (1). Six subjects rwith at least one e...
Scientific Reports
Individuals with complete cervical spinal cord injury suffer from a permanent paralysis of upper limbs which prevents them from achieving most of the activities of daily living. We developed a neuroprosthetic solution to restore hand motor function. Electrical stimulation of the radial and median nerves by means of two epineural electrodes enabled functional movements of paralyzed hands. We demonstrated in two participants with complete tetraplegia that selective stimulation of nerve fascicles by means of optimized spreading of the current over the active contacts of the multicontact epineural electrodes induced functional and powerful grasping movements which remained stable over the 28 days of implantation. We also showed that participants were able to trigger the activation of movements of their paralyzed limb using an intuitive interface controlled by voluntary actions and that they were able to perform useful functional movements such as holding a can and drinking through a straw.
Exploring Selective Neural Electrical Stimulation for Upper Limb Function Restoration
European journal of translational myology, 2016
This article introduces a new approach of selective neural electrical stimulation of the upper limb nerves. Median and radial nerves of individuals with tetraplegia are stimulated via a multipolar cuff electrode to elicit movements of wrist and hand in acute conditions during a surgical intervention. Various configurations corresponding to various combinations of a 12-poles cuff electrode contacts are tested. Video recording and electromyographic (EMG) signals recorded via sterile surface electrodes are used to evaluate the selectivity of each stimulation configuration in terms of activated muscles. In this abstract we introduce the protocol and preliminary results will be presented during the conference.
Frontiers in Neuroscience , 2018
Individuals with tetraplegia identify restoration of hand function as a critical, unmet need to regain their independence and improve quality of life. Brain-Computer Interface (BCI)-controlled Functional Electrical Stimulation (FES) technology addresses this need by reconnecting the brain with paralyzed limbs to restore function. In this study, we quantified performance of an intuitive, cortically-controlled, transcutaneous FES system on standardized object manipulation tasks from the Grasp and Release Test (GRT). We found that a tetraplegic individual could use the system to control up to seven functional hand movements, each with >95% individual accuracy. He was able to select one movement from the possible seven movements available to him and use it to appropriately manipulate all GRT objects in real-time using naturalistic grasps. With the use of the system, the participant not only improved his GRT performance over his baseline, demonstrating an increase in number of transfers for all objects except the Block, but also significantly improved transfer times for the heaviest objects (videocassette (VHS), Can). Analysis of underlying motor cortex neural representations associated with the hand grasp states revealed an overlap or non-separability in neural activation patterns for similarly shaped objects that affected BCI-FES performance. These results suggest that motor cortex neural representations for functional grips are likely more related to hand shape and force required to hold objects, rather than to the objects themselves. These results, demonstrating multiple, naturalistic functional hand movements with the BCI-FES, constitute a further step toward translating BCI-FES technologies from research devices to clinical neuroprosthetics.
IEEE Transactions on Biomedical Engineering, 2018
Objective: Paralysis resulting from spinal cord injury (SCI) can have a devastating effect on multiple arm and hand motor functions. Rotary hand movements, such as supination and pronation, are commonly impaired by upper extremity paralysis, and are essential for many activities of daily living. In this proof-of-concept study, we utilize a neural bypass system (NBS) to decode motor intention from motor cortex to control combinatorial rotary hand movements elicited through stimulation of the arm muscles, effectively bypassing the SCI of the study participant. We describe the NBS system architecture and design that enabled this functionality. Methods: The NBS consists of three main functional components: 1) implanted intracortical microelectrode array, 2) neural data processing using a computer, and, 3) a non-invasive neuromuscular electrical stimulation (NMES) system. Results: We address previous limitations of the NBS, and confirm the enhanced capability of the NBS to enable, in real-time, combinatorial hand rotary motor functions during a functionally relevant object manipulation task. Conclusion: This enhanced capability was enabled by accurate decoding of multiple movement intentions from the participant's motor cortex, interleaving NMES patterns to combine hand movements, and dynamically switching between NMES patterns to adjust for hand position changes during movement. Significance: These results have implications for enabling complex rotary hand functions in sequence with other
Electrical stimulation—a mapping system for hand dysfunction in tetraplegia
Spinal Cord
Study design Retrospective data analysis Objectives To define the distribution of the motor points and excitability of the key wrist and finger actuators in order to detect upper (UMN) and lower motor neuron (LMN) lesions potentially influencing the development of a tenodesis grasp. Setting A rehabilitation centre for spinal cord injuries, Nottwil, Switzerland. Methods Forearm muscles of 32 patients with tetraplegia (AIS AD) were tested bilaterally with electrical stimulation (ES) to differentiate whether UMN or LMN was present. For testing, a standardised mapping was developed. All patients underwent the same positioning schedule. Results Sixteen hands developed a tenodesis grasps, 24 hands showed neither shortening nor tightening of the finger flexors. Two patients developed unilateral tenodesis grasp and showed no tightening of the finger flexors on the contralateral hand. Seven patients developed tenodesis grasps symmetrically and bilaterally, whereas one maintained an essentially open hand without tightening of the finger flexors. All hands that developed a tenodesis grasp showed a LMN lesion of the M. extensor digitorum communis (EDC). The frequency of the tenodesis grasp differed significantly between the groups with and without intact reflex arc (p < 0.0001). Conclusion Surface ES may serve as a diagnostic tool to detect an UMN or LMN lesion of the key actuator muscles affecting the tenodesis grasp. These findings provide information that is essential for the choice of treatment to optimise function of the tetraplegic hand.
Implanted Neuroprosthesis for Restoring Arm and Hand Function in People With High Level Tetraplegia
Archives of Physical Medicine and Rehabilitation, 2014
Objective: To develop and apply an implanted neuroprosthesis to restore arm and hand function to individuals with high level tetraplegia. Design: Case study. Setting: Clinical research laboratory. Participants: Individuals with spinal cord injuries (NZ2) at or above the C4 motor level. Interventions: The individuals were each implanted with 2 stimulators (24 stimulation channels and 4 myoelectric recording channels total). Stimulating electrodes were placed in the shoulder and arm, being, to our knowledge, the first long-term application of spiral nerve cuff electrodes to activate a human limb. Myoelectric recording electrodes were placed in the head and neck areas. Main Outcome Measures: Successful installation and operation of the neuroprosthesis and electrode performance, range of motion, grasp strength, joint moments, and performance in activities of daily living. Results: The neuroprosthesis system was successfully implanted in both individuals. Spiral nerve cuff electrodes were placed around upper extremity nerves and activated the intended muscles. In both individuals, the neuroprosthesis has functioned properly for at least 2.5 years postimplant. Hand, wrist, forearm, elbow, and shoulder movements were achieved. A mobile arm support was needed to support the mass of the arm during functional activities. One individual was able to perform several activities of daily living with some limitations as a result of spasticity. The second individual was able to partially complete 2 activities of daily living. Conclusions: Functional electrical stimulation is a feasible intervention for restoring arm and hand functions to individuals with high tetraplegia. Forces and movements were generated at the hand, wrist, elbow, and shoulder that allowed the performance of activities of daily living, with some limitations requiring the use of a mobile arm support to assist the stimulated shoulder forces.
ABSTRACTBackgroundParalysis after spinal cord injury involves damage to pathways that connect neurons in the brain to peripheral nerves in the limbs. Re-establishing this communication using neural interfaces has the potential to bridge the gap and restore upper extremity function to people with high tetraplegia.ObjectiveWe report a novel approach for restoring upper extremity function using selective peripheral nerve stimulation controlled by intracortical microelectrode recordings from sensorimotor networks, along with restoration of tactile sensation of the hand using intracortical microstimulation.MethodsA right-handed man with motor-complete C3-C4 tetraplegia was enrolled into the clinical trial. Six 64-channel intracortical microelectrode arrays were implanted into left hemisphere regions involved in upper extremity function, including primary motor and sensory cortices, inferior frontal gyrus, and anterior intraparietal area. Nine 16-channel extraneural peripheral nerve elect...
Implantable functional neuromuscular stimulation in the tetraplegic hand
The Journal of Hand Surgery, 1989
Functional neuromuscular stimulation of the upper extremity provides manipulative capacity to persons with high level tetraplegia who have insufficient voluntary muscles available for tendon transfer surgery. We report an enhancement of the technique to include surgical implantation of a multichannel receiver-stimulator, sensory feedback stimulation, and tendon transfers. Tendon transfers were done with spastic, rather than voluntary motors employing standard surgical techniques. The system described has been operational for more than 1% years. (J HAND SURG