- Training Complexes
- Computerized Method of Comprehensively Assessing the State of Vestibular Function, Sensory Interactions, and Visual Tracking
- Computerized Method of Non-Pharmacological Treatment and Prevention of Vertigo, Dizziness and Equilibrium Disturbances
- Hardware-software complex “OCULOSTIM–CM”
Laboratory of VESTIBULAR PHYSIOLOGY was awarded the State Prize of the Russian Federation in the field of Science and Technology (2002); laboratory staff have issued and received 9 patents; together with specialists from the LLC Scientific-Medical Firm “STATOKYN” and LLC Scientific-Production Association “INNOVATIVE MEDICAL TECHNOLOGIES” laboratory is working on the development of methodology and the creation of innovative hardware-software complexes (HSC) («SENSOMOTOR», «VIRTUAL», «OCULOSTIM», «OCULOSTIM-CM»), allowing:
- to conduct research and assess the state of the vestibular function, intersensory interactions and almost all forms of visual and visual-tracking in weightlessness, during readaptation to Earth’s gravity after spaceflight, as well as in model and clinical conditions;
- to objectify systemic (vestibular) vertigo and non-systemic (psychogenic, cardiogenic, functional) dizziness and equilibrium disturbances, perform diagnostics and prognosis of vestibular disorders, disorders of visual and visual-tracking tracking using computerized means;
- to perform therapy, correction and prevention of sensorimotor, perceptual and autonomic disorders using non-pharmacological computerized method; to conduct trainings to develop the skill of the fixation reflex using biofeedback in complex, dynamic and visual conditions causing disorientation and illusions of spatial position.
Training complexes
In the 1980s, laboratory worked on the creation and carrying out of programs of clinical-physiological assessment of the vestibular function of cosmonauts (which were based on the works of Professor Bryanov I.I. and Professor Yakovleva I.Ya.) as well as space onboard and ground-based scientific experiments. Furthermore laboratory staff worked on scientific and experimental substantiation of new approaches to the training of cosmonauts to the activities related to visual-manual control of complex dynamic systems, for example, such as testing of manual docking to the orbital station. The basis of the new approach to the training of cosmonauts was the principle of combined modeling of major physiological effects of weightlessness: the redistribution of body fluids in the cranial direction and complex of symptoms of motion sickness induced by optokinetic stimulation.
Together with JSC MIC NPO Mashinostroyeniya for the first time there was developed and put into practice of cosmonauts’ training the complex system of training sensory systems applied to the conditions of weightlessness and there was made a specialized training complex (Kornilova L.N., Smirichevsky L.D. et al., USSR patent #165687, 1981), still operated by State Organization “Yu.A. Gagarin Research & Test Cosmonaut Training Center” (Fig. 1). Criterion of preparedness for the spaceflight was successful execution of a simulated docking to the orbital station under antiortostatic conditions (modeling redistribution of body fluids in the cranial direction) and optokinetic stimulation (modeling of “sickness” by creating a pseudo-Coriolis effect) (Kornilova L.N., Smirichevsky L.D. et al., 1980, 1984).
Fig. 1. Training complex to increase resistance to sensory and autonomic disorders in weightlessness
The results of years of research in weightlessness and the analysis of perceptual and sensorimotor disturbances revealed signs of dysfunction of the visual tracking and propose criteria necessary for the development of new control and training methods to optimize the quality of the visual and visual-manual control of the movement of space objects.
Specialists from the State Organization “Yu.A. Gagarin Research & Test Cosmonaut Training Center” (GCTC), M.V. Lomonosov Moscow State University and SSC RF – IBMP RAS (part of which is our laboratory) managed to theoretically substantiate and experimentally prove the possibility of simulating of sensory disturbances on dynamic centrifuge-simulators with mathematical software and information support of cosmonauts training and quality evaluation of their visual-manual control of space objects. The basis of the new professional selection and training of cosmonauts for activities related to visual-manual ergatic complex systems, was the principle of combined modeling of physiological effects of weightlessness on the dynamic centrifuge simulators.
Based on the CF-18 in GCTC there was created a specialized simulator to perform operations of excretion of spaceships into orbit, visual-manual control of motion in orbit and descent to Earth based on the programs of orbital stations “MIR” and ISS (Fig. 2). Radius of gyration – 18m, maximum overload – 30g.
Fig. 2. Dynamic training complex (Centrifuge CF-18)
For the first time in history of space science there was made an intelligent dynamic simulator with a new information support for the selection and training of cosmonauts, and for its creation in 2002 the team of authors (Sadovnichiy V.A., Aleksandrov V.V., Lemak S.S., Grigoriev A.I., Kozlovskaya I.B., Kornilova L.N., Klimuk P.K., Voronin L.I.) was awarded the State Prize of the Russian Federation in the field of Science and Technology (#2363, Fig. 3).
Fig. 3. Diploma of State Prize of the Russian Federation in the Field of Science and Technology
Teamwork «Motion control with sensory disturbances in weightlessness and information ensure of maxi-min quality control of visual stabilization of space objects» consisted of:
- development of an algorithm of accelerational simulation for dynamic centrifuge complexes;
- creating a dynamic simulator (training complex), which allows to simulate all phases of spaceflight;
- development a software for quality control of visual stabilization of space objects;
- creating for the first time in the history of space science a dynamic simulator (training complex) with a new information support.
Computerized Method of Comprehensively Assessing the State of Vestibular Function, Sensory Interactions, and Visual Tracking
Among the many problems that have confronted the medical sciences since humans first began exploring space, one of the main ones is adaptation to the conditions of changed gravitational force. Upon arrival in weightlessness (first three to seven days) and upon the return to Earth (from landing to three to five days later), virtually all crew members experience a number of negative reactions and sensory disorders (orientational illusions, vertigo, dizziness, problems focusing on and tracking visual objects) [Graybiel A. 1967-1980; Kornilova L. N. et al. 1983-2013], which are perceived as uncomfortable and can be exacerbated by additional vegetative and neurohumoral disturbances (increased sweating, nausea, vomiting, etc.) [Yuganov Ye.М. et al. 1968; Bryanov I.I. et al. 1979-1984; Thornton W. et al. 2012].
Weightlessness by itself does not directly influence one’s visual tracking function. However, it significantly changes the activity of a person’s gravitationally-dependent sensory systems (vestibular, tactile, support, and muscular), thus disrupting their usual, evolutionary-based interaction. In weightlessness, information received from the vestibular apparatus does not align with information received from other sensory systems, thus the typical sensory links are broken and the brain cannot correctly interpret the incoming signals at the beginning of flight, leading to the development of space motion sickness. As a result, this causes a decrease in the quality of crew member performance of work tasks, particularly those relating to visual tracking accuracy. There is every reason to believe that the unsuccessful docking of spacecraft, errors in structural assembly, and other instances of errors in manual control that have occurred in orbit were often caused by disturbances in the function of tracking moving space objects because of changes in sensory functions.
Analysis of data accumulated in a series of scientific experiments before, during and after spaceflights on the orbital stations “Salyut-6″, “Salyut-7″, and “MIR” [Yazdovskiy V.I. et al. 1963-1964; Yuganov Ye.М. et al. 1964-1968; Kornilova L.N. et al. 1982-2000] demonstrates that adaptation to weightlessness is accompanied by profound and extensive disruptions in visual tracking, vestibular function, and central disruptions of sensory links, which require a certain amount of time to be restored upon the return to Earth. However, the existing methodological approaches and hardware-software complexes did not provide answers to many questions regarding the mechanisms and patterns of the adaptation processes in the vestibular and interacting sensory systems, above all the oculomotor system. Therefore, specialists from the laboratory of VESTIBULAR PHYSIOLOGY at the Institute of Biomedical Problems over the years developed and in 2007 patented a “COMPUTERIZED METHOD OF COMPREHENSIVELY ASSESSING THE STATE OF VESTIBULAR FUNCTION, SENSORY INTERACTIONS, AND THE EYE TRACKING FUNCTION” (Russian Federation patent #2307575 dated 10/10/2007, Kornilova L. N. et al. – Fig. 4).
Fig. 4. Russian Federation patent #2307575, 2007
The computerized method is above all designed to assess and predict the functional state of the vestibular-visual system, visual tracking, and spatial orientation in crew members of space expeditions. In order to implement this method, in collaboration with the LLC Scientific-Medical Firm “STATOKYN” and LLC Scientific-Production Association “INNOVATIVE MEDICAL TECHNOLOGIES” there were created the hardware-software complexes (HSC) “OCULOSTIM-CM”, “VIRTUAL”, and “SENSOMOTOR”.
At the basis of the method lies the assessment of oculomotor reactions — both spontaneous (with eyes open and closed) and “induced” by visual stimulation appearing on a screen or by active movements of the head (vestibular stimuli) while using the entire computerized testing system:
- visual tracking of a target/stimulus that is steadily moving linearly or in a pendulum-like motion horizontally, vertically, diagonally, or in a circle;
- fixating and tracking an abruptly (saccadically) moving target horizontally, vertically or diagonally;
- fixating and holding the gaze on a real (visible) or imaginary (invisible) target;
- vestibular tests with the head tilted to the shoulder or active rotation of the head.
The visual tracking tests are conducted both with visual targets on a clean (black) field on the screen and against a backdrop of additional visual interferences (diffuse spots/ellipses moving horizontally or vertically) to “irritate” the peripheral vision. During the testing, movements of the eyes (by electro- and video-oculography) and head (using 3-d angular rate sensors and accelerometers) are recorded.
The oculomotor system is controlled by a complex hierarchy of innervation mechanisms located at different levels of the nervous system. The use of a special test battery makes it possible to evaluate the disruptions occurring in various forms of eye movements and, given the known mechanisms of how these movements are performed, to find the causes of these disturbances. Thus the basis for objective diagnostics is created.
Currently, this method is actively used during the pre- and post-flight clinical-physiological assessment of International Space Station (ISS) crew members (since 2001) in experiments aboard the ISS (space experiments “VIRTUAL” (Fig. 5) and “PURSUIT” since 2013 and 2015, respectively) and after crew members return to Earth (scientific experiments “SENSORY ADAPTATION” and “GazeSPIN” since 2001 and 2009, respectively).
Fig. 5. Space experiment “VIRTUAL” aboard the International Space Station in 2013 during ISS-37/38/39 expeditions
The pre- and post-flight examination of 40 Russian ISS crew members in long-term spaceflight showed [Kornilova L. N. et al. 2007-2013]:
- drop in the otolith function of the vestibular apparatus;
- increase in reactivity of the semicircular canals of the vestibular apparatus;
- change in the nature of the interaction between the otoliths and semicircular canals;
- change in the central mechanisms of sensory interactions, accompanied by a reliable deterioration in the amplitude, speed and time characteristics of visual tracking, as well as the development of a new tracking strategy (tracking a steadily moving target using a set of abrupt movements/saccades).
The visual tracking function disruptions observed led to a significant (three-fold and more) increase in the time needed to recognize and acquire a target and fixate the gaze on it. The post-flight diversity of disturbances point to the involvement of all levels of vestibular and eye movement innervation mechanisms in the development of said disturbances.
The methodology and developed hardware-software complexes may be used in more than just the training, medical monitoring, and professional selection of crew members. The research conducted demonstrated the high effectiveness of the computerized method and developed hardware-software complexes in diagnosing the condition of the vestibular and its related sensory systems (primarily visual) and in assessing the stability of static and dynamic spatial orientation:
- in experiments simulating weightlessness (immersion and bed-rest);
- in examining highly qualified athletes (high-performance sports — gymnastics, figure and speed skating, target shooting, etc.);
- in diagnosing and treating patients suffering from vertigo, dizziness and equilibrium disturbances;
- in evaluating the effectiveness of medications (betahistine drugs Betaver and Betaserc).
The computerized method and hardware-software complex “OCULOSTIM-CM” were successfully approved and certified in clinical studies (200 patients complaining of vertigo, dizziness and equilibrium disturbances) together with specialists from the Nervous Diseases Department of the I.M. Sechenov First Moscow State Medical University, the Academician Alexander Vein Clinic for the Treatment of Headaches and Vegetative Disorders, and the Federal Scientific Clinical Center of Otorhinolaryngology.
The application in clinical practice of the created method made it possible to develop diagnostic criteria and classification functions to determine the type of vestibular disorder (peripheral, cerebral or psychogenic vestibular pathology), offering the possibility to quickly conduct an initial differential diagnosis of vertigo, dizziness and balance disturbances while minimizing additional expensive clinical testing using neuro-visual and other instrumental tools.
Computerized Method of Non-Pharmacological Treatment and Prevention of Vertigo, Dizziness and Equilibrium Disturbances
It is well known that spaceflight in weightlessness is accompanied by the occurrence of illusions of spatial position or displacements of the body, vertigo, dizziness, disruption of coordination, and difficulty fixating on and tracking visual objects [Graybiel A. 1967-1980; Kornilova L.N. et al. 1983-2013]. Frequently this condition is perceived as uncomfortable, particularly with the presence of additional vegetative symptoms (increased sweating, nausea, vomiting, etc.) [Yuganov Ye.М. et al. 1968; Bryanov I.I. et al. 1979-1984; Thornton W. et al. 2012]. The disturbances that occur, referred to as space motion sickness, negatively affect both the health of crewmembers and the quality of their work performance in flight.
At the present time, medications are typically used to eliminate the symptoms of space motion sickness.
Pharmacological substances have a number of contraindications and side effects which can have a negative effect on various types of professional activity. The effect of their action lasts a limited amount of time and stops after the medication is eliminated from the system.
Thus the need is obvious to develop non-pharmacological methods of preventing and treating space motion sickness, since such methods does would have the aforementioned shortcomings. An important advantage to the non-pharmacological approach is its universality when applied to decreasing or eliminating the unfavorable symptoms of space motion sickness.
It is well known that people in extreme professions, such as mountain climbers, athletes, acrobats, and ballet dancers develop the capability to suppress unfavorable vestibular reactions at the moment high accelerations act on them, by developing a fixation reflex.
Attempts have been made by many clinicians to train patients with congenital or acquired vestibulopathies to suppress paroxysmal vertigo and vegetative episodes using a fixation reflex [Cawthorne T., Cooksey F., 1945; Dix M., Hood J., 1987; Hood J., Korries S., 1999; Blagoveschenskaya N.S., 1990; Likhachov S.А., Skliut I.А., 2000, 2008; Brandt T., 2014 et al.].
The existing approaches do not enable the development of the sensory-motor skill (fixation reflex) under conditions induced by vestibular and visual stimulation of vertigo. Therefore, specialists from the laboratory of VESTIBULAR PHYSIOLOGY at the Institute of Biomedical Problems developed and patented a “COMPUTERIZED METHOD OF PREVENTING AND CORRECTING OF UNFAVORABLE PERCEPTION AND SENSORY-MOTOR REACTIONS” (Russian Federation patent #2301622 dated 06/27/2007, Kornilova L. N. et al. – Fig. 6)
Fig. 6. Russian Federation patent #2301622, 2007
The innovation of this method is in creating a differentiated approach to the training of patients depending on their disease (type of vestibulopathy) and selecting the most effective means of training (visual, vestibular, or combined) for them using biofeedback.
During patient training, depending on the nature of the vertigo, dizziness or equilibrium disorder and of his/her disease (type of vestibulopathy), a series of training sessions is conducted to develop a fixation reflex using biofeedback, provided by the computerized using this method to record eye and head movements.
The computerized method of non-pharmacological training is based on:
- inducing unfavorable illusions and self-rotations (vertigo) and sensory-motor (nystagmus and equilibrium disturbance) reactions in the individual;
- training to correct or mitigate the induced negative reactions using a fixation reflex on an actual (visible on a screen) and imagined (invisible) target;
- using biofeedback to assess the effectiveness of the efforts applied (self-monitoring of training results) by the individual.
The method involves three types of training:
- visual method – to develop a fixation reflex against a background of moving visual interferences (diffuse spots/ellipses) to “irritate” the peripheral vision (Fig. 7);
Fig. 7. Visual method of training
- vestibular method – to develop a fixation reflex with active head movements;
- combined method – to develop a fixation reflex against a background of moving visual interferences and head movement.
Training is conducted until the negative reactions (vertigo, dizziness and equilibrium disturbances) the patient suffers from in daily life or during professional activity disappear or are significantly reduced. The therapeutic effect of the training is assessed through a follow-up clinical/neurological examination and the use of the computerized method of comprehensively assessing the state of vestibular function and visual tracking (Russian Federation patent #2307575 dated 10/10/07, Kornilova L. N. et al.). The indicator of training success is the suppression of experimentally induced negative reactions (full or partial) during the action of visual and vestibular stimuli while fixing the gaze on an imagined target.
The non-pharmacological computerized method for treating and preventing of vertigo, dizziness and equilibrium disturbances was tested in clinical conditions jointly with specialists from the Nervous Diseases Department of the I.M. Sechenov First Moscow State Medical University, the Academician Alexander Vein Clinic for the Treatment of Headaches and Vegetative Disorders, and the Federal Scientific Clinical Center of Otorhinolaryngology.
The results of the clinical work demonstrated that patients acquired the capacity to fixate on and hold the gaze on both real and imagined targets, thus suppressing (fully or partially) vertigo, dizziness, nystagmus, and equilibrium disturbances. It was shown that training effectiveness depended not only on the disorder (type of vestibulopathy), but also on the type of training selected. For patients with peripheral vestibulopathies, the most effective was visual training; for patients with central (cerebral) vestibulopathies, the vestibular method was best; and for patients with psychogenic vestibulopathies, the combined method was preferred.
Analysis of special questionnaires demonstrated that all patients with psychogenic vestibulopathies, 91% patients with peripheral vestibulopathies, and 80% of patients with central vestibulopathies subjectively noted “good suppression of vertigo/dizziness in everyday conditions” and “improvement in general adaptation to real life conditions.”
The effectiveness of the non-pharmacological computerized method has made it a good candidate for use both during the pre-flight training of ISS Russian crewmembers, and during spaceflight, to suppress the symptoms of space motion sickness. The suppression of negative reactions during flight using the fixation reflex has been successfully applied by crewmembers on board the ISS since 2013.
Hardware-software complex “OCULOSTIM–CM”
COMPUTERIZED METHOD FOR COMPLEX DIAGNOSTICS AND NON-PHARMACOLOGICAL TREATMENT AND PREVENTION OF VERTIGO, DIZZINESS AND EQUILIBRIUM DISTURBANCES
Hardware-software complex (HSC) “OCULOSTIM–CM” – is a clinically-modified, portable, mobile complex for diagnostics, therapy and rehabilitation, and allows:
- to objectify and diagnose clear and hidden pathology in the central nervous and vestibular systems;
- to train the subject to correct and inhibit unfavorable vertigo, dizziness and balance disorder by developing a fixation reflex using a biofeedback;
- to estimate the efficiency and patient’s performance during remedial and rehabilitation actions.
HSC “OCULOSTIM–CM” can be used in:
- medical surveys and assessments;
- occupational selection;
- sports medicine;
- experimental research studies;
- non-pharmacological prophylaxis and therapy of paroxysmal conditions and disorders (vertigo, dizziness, visual illusions, autonomic disoders and equilibrium disturbances etc.).
Components of the HSC “OCULOSTIM–CM”:
- PC / notebook (for doctor) + projector / 2-nd widescreen monitor (for subject) for presentation of various visual and/or vestibular stimulation, and real-time control of received results with possible biofeedback.
- EOG-recorder – a special digital DC-device to record eyes (4-channel EOG) and head movements (3D angular velocity and linear acceleration sensors).
- Joystick to record hand movements in studying of visual-manual tracking and to record illusory reactions in studying of vections.
- Software – stimulation, registration of physiological signals, centralized storage and processing of data received.
Fig. 9. Examination on the HSC “OCULOSTIM–CM”
HSC “OCULOSTIM–CM” speeds up the examination’s and assessment’s procedure and operatively produces an objective, diagnostically-important information about various levels of the central nervous system by evaluating and analyzing of spontaneous and evoked oculomotor reactions.
Fig. 10. Visual stimulation’ tests of the HSC “OCULOSTIM–CM”
Fig. 11. Vestibular stimulation’ tests of the HSC “OCULOSTIM-CM”
Computerized tests of the HSC “OCULOSTIM–CM” allows to study:
- spontaneous eye movements;
- nystagmus (spontaneous, optokinetic, vestibular etc.);
- visual tracking (static and dynam saccades, fixation and gaze holding, smooth pursuit);
- illusory reactions (vections) ;
- perception of a subjective visual vertical;
- static torsional otolith-cervical-ocular and otolith-ocular reflex (using additional videooculography complex);
- dynamic vestibular-ocular reactions and vestibular reactivity.
All tests can be carried out with and without (clear background) additional retinal optokinetic stimulation.
The methodology developed and the created HSC “OCULOSTIM-CM” allow to carry out:
- expert diagnostic assessment of the vestibular function and objectification of complaints of vertigo, dizziness and equilibrium disturbances using specially developed computerized tests based on registering of spontaneous, visually- and vestibular-induced eye movements;
- formation of reliable diagnostic criteria for differential diagnosis of vestibular disorders of different genesis using analysis of characteristics of eye movements;
- detecting the presence and type of vestibulopathies in different groups of patients in the clinic and in extreme (special) professions;
- therapy and prevention of vertigo, dizziness and equilibrium disturbances using non-pharmacological computerized method and training to develop the skill of the fixation reflex.
HSC “OCULOSTIM–CM” received approval and is successfully used in:
- clinical practice (rehabilitation, neurology, otorhinolaryngology, ophthalmology);
- occupational selection and medical control (including the ISS-cosmonauts, highly-skilled sportsmen);
- scientific experiments and research studies (“dry” immersion, hypokinesis, bed-rest);
- evaluation of the effectiveness of pharmacological medicine (betahistine etc.);
- rehabilitation after neurologic diseases and traumas.
Fig. 12. Before treatment (patients № 1 и 2)
Fig. 13. After training session on the HSC “OCULOSTIM–CM” (№ 1) and taking the betahistine drugs (№ 2)