The next decade will see an increased use of wearable robotics in neurorehabilitation, including exoskeletons that enable the immobile to stand, walk, and even climb stairs. Despite the notion that only bio-inspired robots can alter the rehabilitation field, there have been limited attempts to develop user-centered robotic technologies. The proposal aims to generate new knowledge on the multisensory modulation of motor bodily experiences, and the impact of adopting an embodied approach when using robotic legs in cases of brain-body disconnection. An overall consensus is being reached on the importance for the future evolution of human robotic technologies of adopting an embodied approach, taking advantage of the brain's plasticity to allow bionic limbs to be mapped within the neural circuits of physically impaired individuals. This proposal will put EXO -expert/-no expert and therapists at the core of the process and optimally utilize the latter's knowledge and expertise, while promoting cognitive and physical human-to-human, EXO-mediated interactions. Due to the key role of sleep in offline memory reprocessing and plasticity, with new motor skill memories still being processed "offline" during consolidation, we also hypothesize that sleep changes can track plastic cerebral modifications related to tool use, predicting functional recovery.
Spinal cord injuries are among the most dramatic causes for immobility, particularly in young adults in their early thirties. These patients are forced to live decades in a state of massive sensory de-afferentation and motor de-efferentation and confined to a wheelchair. In addition to considerable personal and bio-psychological impacts, the short- and long-term socio-economic consequences are also high. Although robotic exoskeletons can help individuals with SCI to walk again, they are still perceived as external objects that do not belong to the body, and hence, treated as a foreign object, which is dangerous and causes fatigue. The dropout rate among patients that used exoskeleton remains high, with most preferring the wheelchair. The greatest need and desire of the patients with SCI are clearly defined and translated in this specific requirement: a major interface between the robotic legs and the body. In particular, the specific outcomes described in this proposal facilitate new modalities that can remap sensory signals and augment experiences, helping paralyzed patients to rapidly train their minds to include the bionic legs and immediately start standing. Through specific research to enhance and extend the human body form, we provide new avenues of exoskeleton perception and use. The proposal also provides an important scientific platform to study neural plasticity. Expected cerebral plastic changes could be reflected by sleep changes across the EXO training. Sleep plays a key role in offline memory reprocessing and plasticity, with new motor skill memories still being processed "offline" during consolidation [35]. EEG recordings have demonstrated that changes in slow-frequency activity, circumscribed to the cortical area involved in learning, follow: intensive pre-sleep visuomotor learning [25]; arm immobilization [36]; and prosthetic learning in a rodent model [37]. However, direct evidence on the impact of prosthetic learning is still lacking in humans.
New forms of unified perception are available by augmenting the human interaction capabilities and awareness of the exoskeleton and stimulating the mapping of an artificial object to appropriate sensory modalities or brain regions dedicated to lower-limb control, thus decreasing the maladaptive cortical reorganization that typically follows the injury. The fusion between the human body and its surrogate physical representation is an advanced example of confluence between the human and technological realms, with strong translational/industrial/economic implications to immobile patients. The research described in our proposal has the potential to change the way in which the healthcare system views the prognosis and standard of care for individuals with SCI. The ability to stand and walk with bio-inspired exoskeleton contributes to reduced risk of complications and recurrent health problems (diabetes and cardiovascular disease, pain, and spasticity) that are related to the sedentary state. The development of bio-inspired exoskeletons may change the way we think about the prognosis of patients with SCI, and could potentially help reinvent the lives of many immobile individuals. The potential impact of standing and walking immediately after suffering a spinal cord lesion will lead to better mental and physical health and functioning, reduced use of medical resources, and an increased quality of life. The physical benefit of standing upright will improve physical functioning, while the benefit of being able to look people in the eye will increase social participation and independence, thus reducing the feelings of isolation and depression that are common in patients with SCI. The proposed research will pave the way for making EXOs much more flexible and usable than the currently available versions and will provide paralyzed patients with more autonomy and daily-life independence within a short time. The new EXOs may ultimately allow the usually young affected to achieve a higher degree of independence sooner, and experience being back in the social world. It is our hope that the bio-inspired exoskeletons can entirely free the patients from wheelchairs in the future.