ИСТИНА

Introduction Kerdo index (KI) originates from hemodynamics and reflects the autonomic nervous system (ANS) tone changes [1]. We have expressed KI in SI unit [2]. Sympathetic and parasympathetic tone balance reflects the dynamic balance of energy expenditure and energy recovery of the body. During physiological sleep KI drops below the level of the individual zero. Modern noninvasive somnological equipment allows getting the KI sample available for subsequent mathematical modeling and quantification of ANS-balance Objectives To quantify the adequacy of the physiological recovery during the sleep. Materials and Methods Hemodynamic parameters were recorded (BPd/HR) in 8 men, including the volunteers of Mars-500 program during the 24 h monitoring using the cardiomonitor SomnoWatch-TM-Plus-BP (SomnoMedics, Germany). KI samples volumes were at least 20 000 values for each test subject. KI measurements results were fitted separately at intervals corresponding to the period of wakefulness and subsequent sleep period to determine what kind of ANS tone prevailed on the 24 h interval. Results and Discussion We have developed a set of numerical procedures to allow finding of the stochastic or dynamic models of individual ANS tone. We have obtained the ways to use model results for numerical estimation of physiological recovery during the sleep. In cases where the areas of figures (corresponding to the number of sympathetic and parasympathetic tone) were equal, the recovery was assessed as successful for 7-8 hours of sleep. In cases where the number of sympathetic tone for the period of waking exceeded the number of parasympathetic tone for period of sleep, recovery was assessed as inadequate. The method also is applicable for the assessment of recovery after energy expenditure physical activity. Eutonic IK value was calculated as the individual mean value in rest for 365 days. Conclusions A noninvasive method for quantitative evaluation of recovery properties of sleep, based on 24 h Kerdo index monitoring can be used to assess the quality of a persons sleep under the influence of extreme factors, including the conditions of space flight. The method is applicable for the assessment of recovery after energy expenditure physical activity. 1. Kerdo I. Ein aus Daten der Blutzirkulation kalkulierter Index zur Beurteilung der vegetativenTonuslage // Acta neurovegetativa. 1966. Bd. 29, N 2, s. 250-268. 2. Demin A.V., Ivanov A.I. The physical interpretation of autonomic Kerdo index // Education,science and research st. 2013. N 2, pp. 151-156.