Моделювання біологічних об’єктів при розробці пристрою для транскраніальної стимуляції постійним струмом

In medical practice, electrotherapy procedures based on the effects of currents of different frequencies are used for treatment and prophylaxis. Their mechanisms of action and characteristics of incentives in different biological structures are studied insufficiently. The actuality of work is due to thepresence of a wide range of pathological and limiting states that are subjected to treatment through physiotherapeutic effects on various parts of the nervous system, which is confirmed by studies of leading universities of the world and a significant interest of users of typical devices for: rapid recovery of physical condition (replacement of pharmacological agents); stimulation of physical abilities of an organism (training of athletes); stimulation of mental abilities (preparation for examinations); treatment of speech impairment in the sensitivity of psychological and emotional state. An analysis of the paths of current propagation with non-invasive effects requires the consideration of possible biophysical mechanisms of the effect of weak current on the brain through the ankle electrodes. The amount of energy supplied to the patient and the depth of the signal penetration is a factor in the effectiveness of stimulation, because due to the correct choice of these parameters, the period of treatment decreases and the effectiveness of the procedure increases. The basic principle of neurostimulation is to obtain an optimal physiological effect under the condition of minimal side effects, which determines the use of different currents, depending on the tissue excitability and their functional state. The physical bases of transcranial stimulation by direct current areanalyzed in the article. The equivalent electrical scheme of the model of the investigated object is substantiated. The behavior of biological structures is described by an equivalent electric circuit, the resistors and capacitors of which correspond to the resistance and capacitance of the membrane and the intercellular fluid. The construction and modeling was carried out in Micro-Cap 9.As a result of a computer experiment, it became clear that a cell conglomerate can be replaced by one equivalent cell: the nature of the impedance curve does not change, and only its spreading varies