In manual pressure: an anatomical exocyst restores movement after stroke

Russian developers have created a new complex for restoring motor activity after stroke and various injuries, as well as rehabilitation of children with cerebral palsy. It registers the brain activity that occurs when a person mentally sends a command to his or her sick arm, and uses an exokisti to put the limb in motion. It does this as naturally as possible. In this way, neuroplastic processes are triggered in the brain, which allow the restoration of disturbed functions. According to experts, recognizing brain activity with the help of electroencephalogram (EEG) together with mechanical support of movements accelerates rehabilitation, but for effective therapy it is important to take into account the peculiarities of each individual patient.

Natural movements of the exocyst

Specialists of N.I. Pirogov Russian National Research Institute of Medical Sciences of the Ministry of Health have created a new exoskeleton complex "Exokist-M" designed for rehabilitation of post-stroke and post-traumatic patients, as well as children with cerebral palsy. Unlike its analogs, this device is mobile. Due to what it can be installed on a rolling stand, the edge of a table or a bed and can be used to work with bedridden patients who have a chance to restore motor function of limbs. The complex integrates a brain-computer interface that records electroencephalography signals and hand exoskeletons controlled by this interface. Its operating principle is based on the reinforcement of a mental representation or an attempt to open or squeeze the hand through the operation of the exoskeleton and visual feedback.

Another peculiarity of the development is that the engineers managed to maximize the anatomicality of the patient's hand movements under the action of the exoskeleton design, which increases the effectiveness of rehabilitation. The developers also offered a unique set of classifiers for recognizing EEG data, an original artifact suppression unit, an expanded set of game scenes for performing exercises and the ability to use various devices for recording brain activity. The creation of the complex has become an interdisciplinary task.

- It is difficult to single out any part: without the accumulated fundamental knowledge it would have been impossible to formulate the concept itself, to understand what patterns of brain activity are the target of classification, to create a brain-computer interface and assume its usefulness for rehabilitation. The mathematical and IT part of the work is important to create a classifier for this interface, a reliable software part of the complex, and a motion control system for the exoskeleton. The engineering part is to design the exoskeleton itself. At the same time, the medical part is critical: it is not enough to make physiologically based assumptions about the benefits of the procedure - its effectiveness must be proven in a clinical trial. In addition, the creation of the program and the exoskeleton is impossible without the participation of doctors," said Pavel Bobrov, a senior researcher at the Department of Neurocomputer Interfaces at the Pirogov Engineering Center of the Russian National Research Institute of Medical Sciences.

The feedback allows the patient to actively participate in the training. The combination of EEG recognition of activation of brain motor network areas and execution of movement by the exoskeleton triggers neoplastic processes that accelerate recovery or improvement of disturbed movements. In fact, the complex is a simulator on which a person trains his or her brain.

Why does the exoskeleton read brain activity?

During rehabilitation, a patient with EEG electrodes in place sits in a chair in front of a monitor screen. He or she is given visual cues about what mental task to perform - to relax or visualize opening or contracting the hand. For children, the cues can be in game form. After several performances of each task, the EEG classifier is trained and then recognizes which task the person is currently performing. If this task matches the cue, the person receives feedback: the exoskeleton starts moving.

The mobile version of the complex differs from the stationary one in the presence of fully wireless communication and improved possibilities of adjusting the patient's hand attachment. It is now possible to use any hand size within one complex: from pediatric to adult.

Motion representation is actively used in stroke rehabilitation. It allows to realize almost all principles of modern neurorehabilitation: active participation of the patient himself, high intensity, regularity of training, biofeedback.

- Rehabilitation with the use of such technologies has its advantages, as it does not require invasive solutions, as well as allows you to work with patients of any age. Of course, it is necessary to take into account the patient's anamnesis to select the right solutions in the application of such methods for rehabilitation, - said Yuri Matvienko, Head of Neurotechnology Department at Motorika, a participant in the NTI Neuronet market.

The use of technologies with EEG electrodes allows monitoring the dynamics and obtaining biological markers of changes in the patient at the level of taking signals from the brain to select tactics for further rehabilitation, the expert added.

- The principle of work of the Exokist-M complex, based on the brain-computer interface and mechanical support of movements, promotes the activation of neuroplastic processes and accelerates the recovery of lost motor functions. Such approaches correspond to modern trends in medicine aimed at personalized and active rehabilitation of patients. In addition, the possibility of use in children with cerebral palsy expands the scope of application of the complex," said Alexander Zakharov, Director of the Research Institute of Neurosciences of SamSMU, an expert of the Healthnet STI market.

The described technology has great potential in the fight against the consequences of stroke. It is very important that such projects are successfully implemented and the technology reaches application in clinical and rehabilitation units, not only in the Pirogov RNIMU circuit, but in general throughout the country, noted Stanislav Ottavnov, Head of the Laboratory for Analysis of Population Health Indicators at MIPT.

In general, exoskeletons for rehabilitation exist abroad as well, for example, developments using brain-computer interfaces, such as NeuroExos and Hand of Hope. The key advantage of Exokist-M is the integration of EEG control with active feedback, which makes the training process more natural and effective. The possibility of adaptation for children and a playful training format also make it stand out among similar solutions, says the specialist.