ReGAIT: A new rehabilitation approach of locomotion for incomplete spinal cord injury patients by integrating neural interfaces, lower-limb powered robotic systems and transcutaneous spinal current stimulation strategies
SUBPROJECT 1: Development of a self-tuned Neural-Machine Interface for closed-loop control of lower-limb exoskeletons (PID2021-124111OB-C31)
- Principal Investigators: José M. Azorín & Eduardo Iáñez
- Center: Miguel Hernández University of Elche, Spain
SUBPROJECT 2: Design of transcutaneous spinal current stimulation strategies for rehabilitation of gait
- PIs: Hatice Kumru & Mark Wright
- Center: Guttmann Institute, Spain
SUBPROJECT 3: Development of a novel strategy to analyze the effect on gait biomechanics when combining lower-limb powered exoskeletons controlled by Neural-Machine Interfaces and transcutaneous spinal current stimulation in incomplete spinal cord injured patients
- PI: Angel M. Gil-Agudo
- Center: Hospital for Paraplegics, Spain
Abstract
Spinal Cord Injury (SCI) is one of the major motor disorders due to damage in the human nervous system leading to physical impairment in Western society. These conditions will in general disrupt sensory and motor pathways that in turn lead to permanent pathological gait, resulting in impaired independent ambulation. Subsequent restoration of motor function is often variable and incomplete. Usually, therapists try to recover some residual ability for movement when possible, acting over the distal physical level, trying to influence the neural system through mechanisms of neural plasticity (BOTTOM-UP approach). Traditional therapies to improve functional ambulation for patients in the sub-acute phase (3-11 weeks post-injury) use overground training and require designed preparatory exercises, observation by a physical therapist, direct manipulation of the limbs during gait over a regular surface, followed by supervised walking. This kind of physical rehabilitation is both physically burdensome and time-consuming for the therapists. With recent advances in robotic technologies, lower-limb robotic exoskeletons have emerged as aids for over-ground, bipedal ambulation for individuals with motor limitations. However, there have been many discussions over the clinical relevance of exoskeletons, being still elusive the specific benefits of long-term use of exoskeletons in gait training.
This project proposes a new approach to produce enhanced neuroplasticity changes during rehabilitation of locomotion in incomplete thoracic SCI patients by associating and synchronizing the use of lower-limb powered robotic systems with neural activity voluntarily generated by patients and with stimulation of the spinal cord. The neural activity will be detected by means of a Neural-Machine Interface (NMI) composed by a Brain-Machine Interface (BMI) based on electroencephalography (EEG) and a Spinal cord Machine Interface (SMI) based on electrospinography (ESG). On the other hand, different transcutaneous spinal current stimulation (tSCS) strategies for rehabilitation of gait will be explored to induce neuroplasticity, selecting the most effective to be synchronized with the lower-limb exoskeleton commanded by the NMI. Thus, the project will combine a TOP-DOWN rehabilitation approach, i.e. association of neural activity voluntarily generated by the patient with the afferent feedback provided by an exoskeleton, and a BOTTOM-UP approach based on transcutaneous spinal current stimulation. It is expected that this new rehabilitation intervention improves brain plasticity, which is believed to be the responsible for functional improvements. To evaluate the performance progress of the gait rehabilitation, new metrics will be defined based on biomechanical analysis techniques. These metrics will allow us to have an objective knowledge of the gait and of the biomechanical and physiological mechanisms of the recovery achieved. The new rehabilitation approach will be evaluated with incomplete SCI patients in two hospitals focused on research and clinical therapies in SCI people: National Hospital for Paraplegics (HNP: Hospital Nacional de Parapléjicos, Toledo, Spain) and Guttmann Institute (IG: Institut Guttmann, Barcelona, Spain), which are members of the consortium of this project.