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BRAIN-COMPUTER INTERFACE: THE FUTURE IN THE PRESENT
стр.4-15
Levitskaya O.S., Lebedev M.A.
Brain-computer interfaces (BCIs) are a promising technology intended for the treatment of diseases and trauma of the nervous system. BCIs establish a direct connection between the brain areas that remain functional and assistive devices, such as powered prostheses and orthoses for the arms and legs, motorized wheelchairs, artificial sensory organs and other technologies for restoration of motor and sensory functions. BCIs of various kinds are currently developing very rapidly, aided by the progress in computer science, robotic applications, neurophysiological techniques for recording brain activity and mathematical methods for decoding neural information. BCIs are often classified as motor BCIs (the ones that reproduce movements), sensory BCIs (the ones that evoke sensations), sensorimotor BCIs (the ones that simultaneously handle motor and sensory functions), and cognitive BCIs intended to regulate the higher brain functions. All these BCI classes can be either invasive (i. e. penetrating the body and/or the brain) or noninvasive (i.e. making no о little contact with the body surface). Noninvasive BCI are safe to use and easy to implement, but they suffer from signal attenuation by scalp and skin, its contamination with noise and artifacts, and an overall low information transfer rate. Invasive BCIs are potentially more powerful because they utilize implanted grids that can both record neural signals in high-resolution and apply stimulation to the nervous tissue locally to deliver information back to the brain. BCI technologies are being developed not only for individual use, but also for collective tasks performed by multiple interconnected brains.
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PRELIMINARY RESULTS OF A CONTROLLED STUDY OF BCI-EXOSKELETON TECHNOLOGY EFFICACY IN PATIENTS WITH POSTSTROKE ARM PARESIS
стр.16-23
Frolov A.A., Mokienko O.A., Lyukmanov R.Kh., Chernikova L.A., Kotov S.V., Turbina L.G., Bobrov P.D., Biryukova E.V., Kondur A.A., Ivanova G.E., Staritsyn A.N., Bushkova Yu.V., Dzhalagoniya I.Z., Kurganskaya M.E., Pavlova O.G., Budilin S.Yu., Aziatskaya G.
The article presents preliminary results of iMove research study. By the time of this publication, the data of 47 patients have been processed. The patients in the experimental group (n = 36) were trained in kinesthetic motor imagery using brain-computer interface (BCI) and a controllable exoskeleton. In the control group, BCI imitation procedures were carried out. In average, the patients had 9 training sessions with a duration of up to 40 minutes. On completing the training, only the experimental group showed improvement in scores (results are presented as median and quartiles (25 %; 75 %)): grasp score increased from 0.5 (0.0; 13.0) to 3.0 (0.0; 15.5) points (p = 0.003) and pinch score increased from 0.5 (0.0; 7.5) to 1.0 (0.0; 12.0) points (p = 0.005) on ARAT scale. In the experimental group, a significant improvement in motor function was found in 33.3 % patients on ARAT scale, and in 30.5 % patients on Fugl-Meyer scale. In the control group, those scores were lower: 9.1 % and 18.2 % patients, respectively.
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STUDYING THE ABILITY TO CONTROL HUMAN PHANTOM FINGERS IN P300 BRAIN-COMPUTER INTERFACE
стр.24-28
Kaplan A.Ya., Zhigulskaya D.D., Kirjanov D.A.
In this work we have tested the assumption that an individual can control a target finger of a phantom by voluntarily focusing his attention on the luminous marker located on that finger in the complex of a P300 wave-based brain-computer interface (P300 BCI) and an anthropomorphic phantom. Because each correct movement of phantom fingers indicates a sufficient mental effort aimed at this action, creating a new ideomotor training simulator of smaller movements of the hand becomes possible. Our study included 21 volunteer subjects of both sexes aged 18-25. It was shown that with P300 BCI complex the subjects learned to control phantom fingers on the first day of the experiment, the percentage of successful attempts being no less than 69 %. Failures were mainly related to the insufficient attention focus on luminous markers on the target phantom fingers. We hypothesize that P300 BCI - Hand Phantom complex can be a basis for developing a fine motor skills simulator.
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DEVELOPMENT OF A NEURODEVICE WITH A BIOLOGICAL FEEDBACK FOR COMPENSATING FOR LOST MOTOR FUNCTIONS
стр.29-35
Bogdanov E.A., Petrov V.A., Botman S.A., Sapunov V.V., Stupin V.A., Silina E.V., Sinelnikova T.G., Patrushev M.V., Shusharina N.N.
Concurrent use of electrophysiological signals of various types, such as obtained from electroencephalogram (EEG), electromyogram (EMG), electrooculogram (EOG), and others, increases the effectiveness of systems for external device control, namely, neural prostheses, exoskeletons, robotic wheelchairs and teleoperated robots. This article presents the results of the first tests of a multifunctional neurodevice capable of detecting EEG, EMG and EOG signals simultaneously (with EOG signals, photoplethysmogram, Sp02 and temperature modules of the neurodevice were used). Measurement results were then compared to the data obtained from KARDi3 device (Medical Computer Systems, Russia) and Fluke 17b multimeter with a plug-in thermistor (Fluke Corporation, USA). The informative value and accuracy of both datasets were comparable. We also studied the effectiveness of EEG and EMG signal hybridization on the basis of the neurodevice of interest; it allowed for an increase of classification accuracy in all subjects by an average of 12.5 % up to the mean of 86.8 % (from 75 to 97 %).
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IMPROVING EYE-BRAIN-COMPUTER INTERFACE PERFORMANCE BY USING ELECTROENCEPHALOGRAM FREQUENCY COMPONENTS
стр.36-41
Shishkin S.L., Kozyrskiy B.L., Trofimov A.G., Nuzhdin Y.O., Fedorova A.A., Svirin E.P., Velichkovsky B.M.
Eye-brain-computer interfaces (EBCIs) could combine the advantages of eye tracking systems used for operating technical devices and brain-computer interfaces. Such systems are intended for both patients with various motor impairments and healthy individuals. The effectiveness of EBCIs is largely dependent on their ability to detect the user’s intent to give a command on the encephalogram (EEG) recorded during gaze fixation, that is, just within hundreds of milliseconds. These strict requirements necessitate a full use of data contained in EEG for more accurate classification of gaze fixations as spontaneous and “control”. This work describes our attempt to use for classification not only amplitude statistical features, but also wavelet features specific to oscillatory EEG components within the interval of 50-500 ms from gaze fixation onset. Integral index of classification accuracy AUC significantly depended on the feature set, reaching the highest value (0.75, average over the group of 8 participants) for the combined amplitude and wavelet set. We believe that further improvement of this method will facilitate the practical application of EBCIs.
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STABILITY OF SPONTANEOUS ELECTRICAL ACTIVITY OF NEURAL NETWORKS
стр.42-46
Sokolov I.S., Tatarintsev M.K., Khasanov R.Y., Azieva A.M., Makarenko E.Yu., Burtsev M.S.
Using brain-computer interfaces, one can both read data from and transmit them to the brain. However, these data are only a set of sensor system signals and not the knowledge or experience. Neural networks are a basis for cognitive activity and can simulate processes similar to learning . In this work we tested the hypothesis of a neural network’s ability to learn by detecting deviations from its stereotypical activity and modifying them in a way that allows it to get rid of external electrical stimulation. Spontaneous activity of several neuronal cultures was analyzed by clustering method. The results showed that activity of untrained cultures remained stable for a long time, and external electrical stimulation led to switching between various spontaneous activity patterns.
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STUDY OF ABLATED SURFACE SMOOTHNESS AND THERMAL PROCESSES IN RABBIT CORNEA TREATED WITH MICROSCAN-VISUM AND MICROSCAN-PIC EXCIMER LASER SYSTEMS
стр.47-51
Kachalina G.F., Takhchidi N.Ch.
In ophthalmology, excimer lasers are used for treating different refractive disorders. The performance of an excimer laser station can be assessed by a number of criteria, such as cornea surface smoothness after the ablation, differences between the diameter of the postoperative optical zone that received full correction and the diameter of the programmed optical zone, and cornea heating during the surgery. The article presents the results of the assessment of three Russian excimer laser systems: MicroScan-PIC 100 Hz, MicroScan-Visum 300 Hz and MicroScan-Visum 500 Hz (Optosystems Ltd.). The smoothness of the ablated surface was measured by New View - 5000 Zygo interferometer (Zygo Corporation, USA). Using PMMA plates, the ablated surface was formed tenfold with each laser as an imitation of the 3.0 D myopia surgical correction, with the optical zone diameter of 6 mm and the transition zone diameters of 2.3 mm for MicroScan-PIC 100 Hz and of 1.9 mm for MicroScan-Visum 300 Hz and MicroScan-Visum 500 Hz. Thermal processes in the cornea were studied in 15 grey chinchillas over 1 year old with a weight of 2-3 kg. With each of the laser systems, phototherapeutic keratectomy was performed on 5 eyes. The smoothest ablated surfaces were formed by MicroScan-Visum 500 Hz. Cornea temperature was the highest here (+ 3.95 °C by the end of treatment), but still within the range of values acceptable for modern scanning type lasers.
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LAPAROSCOPIC RESECTION OF THE HORSESHOE KIDNEY FOR RENAL CELL CARCINOMA
стр.52-56
Muradyan A.G., Vorobyev N.V., Kostin A.A., Tolkachev A.O., Volchenko N.N., Popov S.V., Mamontova I.S.
Renal fusion is one of the most common kidney anomalies. The most frequent is horseshoe kidney, characterized by a fusion of the poles (typically the lower poles) of the kidneys. We described a clinical case of a malignant tumor in the right half of the horseshoe kidney (stage 1 cancer, CTIaNOMO) in a man aged 65 years, who underwent laparoscopic resection. It was shown that laparoscopy is no less efficient than open surgery. However, in planning the operation, it is necessary to use spiral computed tomography for three-dimensional reconstruction of the organ and identification of its anatomical features caused by aberrant blood supply to horseshoe kidney.
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MFTS AND AQSA SCALES VALIDATION IN PATIENTS WITH MULTIPLE AND CONCOMITANT FOOT FRACTURES
стр.57-61
Коrоlеv М.A., Yarmak D.O., Miroschnikova E.A., Korobushkin G.V.
To assess the effectiveness of treatment in traumatology, different scales and assessment questionnaires are used. This work presents the results of the validity test of the two scales designed by the authors, namely, Moscow Foot Trauma Scale (MFTS) and Abbreviated Questionnaire of Subjective Assessment (AQSA). The study enrolled 79 patients (59 male and 20 female individuals with a mean age of 42) with multiple or concomitant foot fractures. For the scales, coefficients of reliability, stability, constancy, internal consistency (Cronbach's alpha), split-half correlation (Guttman’s lambda) and intraclass correlation were calculated. SF-36 (Short Form 36) and AOFAS (American Orthopaedic Foot and Ankle Society Score) were used as reference scales. The study revealed a high reproducibility of the new scales: stability coefficient was 0.85-0.96 for MFTS and up to 0.93 for AQSA. Their reliability and internal consistency were established.
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CHEMILUMINESCENT DETERMINATION OF TOTAL ANTIOXIDANT CAPACITY IN MEDICINAL PLANT MATERIAL
стр.62-68
Vladimirov G.K., Sergunova E.V., Izmaylov D.Yu., Vladimirov Yu.A.
Medicinal plant material is one of the sources of antioxidants for the human body. Chemiluminescence analysis is one of the common methods of determining the content of antioxidants in plant materials. In our work, chemiluminescence analysis was used to determine the total antioxidant capacity (FAC) of fruit decoctions of mountain-ash, rose and hawthorn, as well as raspberry fruit infusion. Experiments established the kinetics of the chemiluminescence of a system consisting of horseradish peroxidase, hydrogen peroxide and luminol. Concentrations and volumes of components of the system were chosen such that strong antioxidants (ascorbic acid) and antioxidants of average force (quercetin) were completely oxidized during measurement (10 minutes). A method for TAC calculation based on changes in chemiluminescence light sum in the presence of plant samples was proposed and substantiated. Analysis of chemiluminescence kinetics showed that antioxidants of average force dominate in the objects studied, including flavonoids and weak antioxidants (tocopherol and others). Comparison of the calculated TAC values for the objects under study and their chemical analysis data showed that products containing the same amount of antioxidants with different ratios of antioxidants by types might vary in their ability to protect the body against the harmful effects of free radicals. The technique described is a promising one for the study of plant objects containing a mixture of different types of antioxidants.
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