A new prosthesis from "Motorika"

Skolkovo has studied the possibility of integrating a bionic prosthetic arm into the human body

Olesya Ukrainskaya, "Regions of Russia"

The Motorika Company, a resident of the Skolkovo Foundation, the FEFU Medical Center and the Vladimir Zelman Center for Neurobiology and Neurorehabilitation of the Skolkovo Institute of Science and Technology summed up the results of the first stage of research on the sensitivity of bionic prosthetic hands and relief of phantom pains.

The project team performed a successful operation to implant electrodes in the peripheral nerves of patients, was able to obtain sustained suppression of phantom pain in patients with electrostimulation, and also conducted a number of sensorimotor tests using haptic communication in the form of invasive and non-invasive electrostimulation. A unique study for Russia confirmed the possibility of conducting invasive neurophysiological studies on the basis of domestic infrastructure with a positive result. The results obtained will facilitate the clinical translation of new neurotechnological solutions in the treatment of phantom pain, and will also allow patients to naturalize the prosthesis by imitating tactile sensations.

The joint project was gaining momentum for 4 years before the team was ready to start the first test study. Surgical operations, rehabilitation of patients and subsequent studies were carried out at the FEFU Medical Center. The company "Motorika" carried out the selection of patients and provided technological support for the project. A team of scientists from Skoltech took over the research part of the project.

The first patients were two men with amputated limbs from the cities of Lermontov and Roslavl. The requirements for patients were quite strict: adults (from 18 years old), with amputation of hands and persistent phantom pains in the area of amputated limbs. 

Dmitry Tsygankov lost his hands at work from a severe electric shock three years ago. In addition to the partial amputation of both forearms, he also had many operations. Dmitry spent three years on treatment and fighting for his life. Dmitry took part in the study in order to solve the problem of phantom pains that interfere with life.

Anatoly Kolot lost his hands in a lightning strike 24 years ago. As a result of the accident, Anatoly partially lost both forearms.  Phantom pains have not receded all these years. And although he was already used to them, Anatoly took part in the study not for himself, but for the sake of science and other people who found themselves in a similar situation. 

On November 26, during the surgical intervention, Anatoly was implanted with two electrodes on the median nerve. At the same time, Dmitry was fitted with three electrodes, on the radial, ulnar and median nerves. The operations were performed by the surgical team of the FEFU Medical Center headed by Artur Biktimirov, a functional neurosurgeon of the FEFU Medical Center, an expert of the NTI Center for Virtual and Augmented Reality neurotechnologies of FEFU. Specialists have gained a lot of experience for the implementation of such breakthrough projects – high-tech treatment at the university clinic is carried out on an ongoing basis. Here they conduct their own research and introduce innovative methods of treatment. In total, neurosurgeons of the Medical Center have already implanted more than 450 spinal and brain stimulation systems in patients with Parkinson's disease, epilepsy, cerebral palsy. Operations are carried out with subsequent testing and control of the adaptation process. 

On November 27, the first connection of the electrodes and the first test stimulation were already carried out. The therapeutic strategy adopted by the team for relieving phantom pains consisted in using a series of small electrical impulses delivered through an electrode located in close proximity to the target peripheral nerve. A series of pulses were delivered by a portable wearable device during the entire time of the study, with the exception of periods of sensorimotor studies. Patients entered their feelings into the observation log to be able to retrospectively track the progress of suppression of phantom pains. 

The main stages of work on the sensitivity of the prosthesis were: mapping the sensitivity of the phantom limb, selecting stimulation parameters to simulate the sensation of touch and compression of the phantom limb, as well as performing tests in conjunction with haptic communication in the form of electrical stimulation.

Anatoly Kolot's steady suppression of phantom pains was detected from the first day. At the same time, the subjective sensation of the phantom hand in the patient acquired unexpected features — with the initial suppression of the phantom burning sensation, he was again able to distinguish the touch and compression of the fingers of the phantom hand. Dmitry's phantom pains did not disappear completely, but decreased by 40-70%. Also, during electrical stimulation, Dmitry Tsygankov had a feeling of general squeezing in his fingers, squeezing his hand into a fist.  A steady sensation of "fist compression" caused by stimulation was used to conduct a test for the difference in the size of the objects taken. Dmitry, being in a mask without the opportunity to observe the prosthesis, was able to successfully distinguish the size of objects clamped in the prosthesis.  

Also, the data obtained will be analyzed by a team of scientists under the guidance of Mikhail Lebedev, Professor and director of the Center for Neurobiology and Neurorehabilitation of Skoltech. But already now we can say that the team is looking forward to 2022 and is planning an expanded stage of the study with an increased number of participants.

Comments

Ilya Cech, Co-founder and CEO of Motorika:
"Our main goal was to solve the technological hypothesis, which is formulated as "is it possible to trigger a sensory response through invasive stimulation of the peripheral nervous system and let a person feel not just how he takes an object, but also the approximate position of the fingers of the hand". We have fully proved that it is technologically and physiologically possible, which opens up huge opportunities for further research. Russian Russian Medical Center, which is located on Russky Island in Vladivostok, we will continue to develop a cyber-medical cluster, a special economic and legal zone for projects and companies engaged in invasive research and technologies, together with the FEFU Medical Center and INTC Russky, which is located on Russky Island in Vladivostok. We want to create a community of Russian developers and engineers, with the involvement of development institutes and foreign partners." 

Yuri Matvienko, Head of the invasive research project of the company "Motorika":
"The results of the first test stage of the study confirmed that our hypotheses are working. Despite the fact that we are not yet able to perform 100% sensitivity of the prosthesis, we realized that this is possible. This gives us an understanding of what work and what preparation needs to be done for the next stage, and how to develop a research protocol. We will also be able to update the methodology for selecting patients for the purity of the study."

Mikhail Sintsov, Junior Researcher Skoltech Center for Neurobiology and Neurorehabilitation: 
"Unexpected for us, in our technological limitations, was the observation in patients in response to the stimulation of stable sensations of "hand compression" or "taking an object", which may be associated with the activation of proprioceptive sensory pathways, but this still needs confirmation. This result in the task of sensitization is unique precisely for the invasive approach, and it could not be reproduced by us using non-invasive epidermal stimulation when mapping the stump. The uniqueness also lay in the fact that the sensation caused was as close as possible to the movement of the prosthetic hand, which we successfully applied for one of the tests to distinguish the sizes of objects."

Gurgen Sogoyan, PhD student at Skoltech Center for Neurobiology and Neurorehabilitation:
During the experiment, it was possible to create sensations that the participants did not experience after the injury. Both patients shared their impressions that their brushes seemed to "come to life" again. The sensations of touch, squeezing, vibration, and the intention to make movements became available to them again after the mapping procedure, which allowed them to determine the most appropriate stimulation settings. Changing the parameters of the electrical action changed both the quality and the area of the sensations experienced, spreading throughout the palm from the fingertips to the wrist. Such "fine-tuning" has become available thanks to an invasive approach.

Mikhail Lebedev, Professor and Head of the Center for Neurobiology and Neurorehabilitation of Skoltech:
"The results obtained exceeded all expectations, because by means of stimulation through the electrodes implanted by Arthur Biktimirov, it was possible to cause sensations that were perceived as tactile sensations in the hand (actually absent after amputation). Moreover, the subjects could use these sensations in the paradigm of active touch, for example, scanning virtual tactile objects. It is thanks to this functionality of artificial sensations caused by stimulation that it was possible to displace phantom pain and replace them with sensitivity approaching normal. Our employees Mikhail Sintsov and Gurgen Soghoyan carefully mapped the artificial sensations caused by stimulation and selected parameters for optimal stimulation. They also recorded an EEG during and without phantom pain. Our colleagues, Daria Kleeva and Kirill Polovnikov, will still carefully analyze these data, but their preliminary analysis has already shown that the state of phantom pain is clustered in a multidimensional neuronal space. This is an important result for understanding the mechanisms of neuropathic pain and for its objective monitoring. In general, an important breakthrough has been made in neurotechnology, which will help many people with amputated limbs and neurological lesions."

Dmitry Tsygankov (patient):
"The results exceeded all expectations. I didn't expect it to be possible. There were various sensations of a real hand, there was a feeling of warmth, a feeling of a living palm. When I was holding a tennis ball, you could really feel it with your fingers. It was just unbelievable." 

Anatoly Kolot (patient):
"I want this to continue. There was a feeling of compression by a living hand, not mechanical, but the compression of a real hand. When the project started, I thought it would only be about getting rid of phantom pains. Phantom pains are easier to overcome than to feel through a prosthesis. Those who will take part in the study in the future may feel something different. But I recommend everyone to try it, it's very interesting." 

Artur Biktimirov, Functional neurosurgeon of the FEFU Medical Center, expert of the FEFU NTI Center in the direction of "Neurotechnologies and VR/AR technologies": 
"In both patients, we managed to achieve a reduction in phantom pain and obtain two types of sensitivity – pressure sensation and perceptual sensitivity. That is, the patient could tell whether his prosthesis was closed or open and whether he was holding an object in the prosthesis. There are a dozen teams around the world dealing with similar problems. But no one has ready-made solutions. The Russian team intends to increase the pace. Now we are analyzing the results obtained, and based on this we will build research processes for the spring of 2022."

Kirill Kayem, Senior Vice President for Innovation, Skolkovo Foundation: 
Since 2014, the team of Motorika, a resident of the Skolkovo Foundation, has been moving step by step from simple to complex in the direction of invasive technologies. There are 4-5 teams in the world that can do this at a high level and find new solutions, and Motorika has already begun to demonstrate results in this complex multidisciplinary field. It is worth noting that in the process of work it was a successful decision to involve the FEFU medical center, Skoltech, I assume that the team will need to be expanded further, the project will be overgrown with new collaborations and approaches, today it is one of the leading projects in the international arena. The whole world has been discussing the possibilities of non-invasive prostheses for a long time, it was assumed that there would be more complex mathematical models and sensors that would be able to shoot myo and brain impulses with the ability to control peripheral devices, so we can say with confidence that invasive technologies are becoming more advanced - this is already a given. In the near future, a person with an implanted system will be able to calmly return to his usual life and easily manage prostheses as real body parts with a significant degree of convenience.

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