Simposio: Nuevos horizontes en la terapéutica de la diabetes mellitus tipo 1. Infusores de insulina automatizados: ¿páncreas artificial biomecánico?

El aumento exponencial en la prevalencia de diabetes mellitus (DM) en todo el mundo incluye también el incremento de personas con DM1. Esta enfermedad se caracteriza por la destrucción autoinmune y en forma progresiva de las células beta pancreáticas, ocasionando una insuficiencia endógena de insulina e hiperglucemia que solo puede controlarse mediante la administración exógena de insulina.La insulinización intensiva con múltiples dosis de insulina es la mejor opción terapéutica para controlar la glucemia y alcanzar los objetivos de hemoglobina glicosilada A1c, con el menor número de hipoglucemias y de riesgo de complicaciones crónicas. Esto requiere de una activa y frecuente participación de la persona con DM1 y que en el tiempo es una barrera para lograr un óptimo control.En pos de alcanzar aquellos objetivos, ha sido amplio y rápido el crecimiento terapéutico tecnológico para DM1 a través del desarrollo de sensores continuos de glucosa (continuous glucose monitor, CGM) y de infusores de insulina subcutánea (continuous subcutaneous insulin infusion, CSII). Desde su aprobación, el uso de los sistemas automatizados de administración de insulina (2017) para adultos, adolescentes y niños con DM1 demostraron ser eficaces y seguros para lograr un adecuado control glucémico en condiciones nocturnas o basales. La infusión automática de insulina (IAI) o lazo cerrado (closed loop, CL) requiere del uso de CSII y CGM comunicados entre sí (por Bluetooth) e integrados funcionalmente a través de algoritmos de control que regulan la administración de insulina según la glucosa subcutánea, llevando la glucemia a rangos deseados para cada paciente. Estos algoritmos se alojan en diferentes plataformas, como un infusor de insulina o teléfono celular o bien de forma remota (Do it yourself o DIY), y desde allí controlan la infusión de insulina según la glucosa subcutánea en forma automática. Los sistemas CL pueden ser monohormonales (solo insulina) o bihormonales (insulina y glucagón), y según requieran o no la participación del paciente en la programación del bolo de insulina pre-comida, se denominan híbridos (hybrid closed loop, HCL) o totalmente automáticos (fully automatic close loop, FCL) respectivamente.Si bien las evidencias observadas en el control glucémico con estos sistemas HCL son alentadoras, los usuarios siguen experimentando la carga del recuento de carbohidratos para los bolos de insulina previo a las comidas. Los pacientes que presentan un deficiente control metabólico debido a que omiten o tardan en administrar los bolos de comida serían beneficiados con los FCL. Estos algoritmos FCL controlan la glucemia prandial sin requerir el anuncio de comida y rápidamente se anticipan y detectan en forma predictiva la variación de glucemia según la carga de carbohidratos, aliviando la carga diaria del cálculo de carbohidratos por parte de los pacientes con DM1. Pocos consorcios en el mundo están avanzando con el difícil desafío que implica la validación de estos algoritmos FCL, uno de ellos en Argentina (automatic regulator of glucose, ARG), y que permitirían alcanzar un adecuado control metabólico con la mejor calidad de vida.

TO CALCULATION OF THE COEFFICIENTS OF AUTOMATIC REGULATOR OF TUNNEL FAN CAPACITY

Analysis of the existing methods for calculating the coefficients of the proportional-integral regulator of the automatic control system for the capacity of the axial fan of the shallow subway was carried out. The technique of calculating the controller coefficients in the Mathlab (Simulink) environment is presented.

Dynamics of Rössler Prototype-4 System: Analytical and Numerical Investigation

In this paper, the dynamics of a 3D autonomous dissipative nonlinear system of ODEs-Rössler prototype-4 system, was investigated. Using Lyapunov-Andronov theory, we obtain a new analytical formula for the first Lyapunov’s (focal) value at the boundary of stability of the corresponding equilibrium state. On the other hand, the global analysis reveals that the system may exhibit the phenomena of Shilnikov chaos. Further, it is shown via analytical calculations that the considered system can be presented in the form of a linear oscillator with one nonlinear automatic regulator. Finally, it is found that for some new combinations of parameters, the system demonstrates chaotic behavior and transition from chaos to regular behavior is realized through inverse period-doubling bifurcations.

Hydraulic automatic regulator of level with flexible working bodies

To eliminate the shortcomings of the known hydraulic autoregulators of the water level, together with Ya. V. Bochkarev, we developed a design of a hydraulic autoregulator of the level with flexible working bodies, combined with an automatic gate for washing sediments, which provides the discharge of floating bodies and bottom sediments in front of the partition structure. To ensure stable vibration-free operation of this hydro-automatic level controller, the task was set to justify the shape and size of the elements of its main gate and the gate-automatic washing of deposits and determine the throughput of the automatic gate washing of deposits. As a result of solving this problem, for the stable vibration-free operation of the hydro-automatic level controller, a non-vacuum shape of the profile of the spillway part of its main gate was adopted, the shapes and sizes of other gate elements were justified, and a theoretical formula for the throughput of the automatic gate for washing sediments was obtained, taking into account the lateral outflows.

Justification of the shape and parameters of the new sorting device for granular materials

The article is devoted to the substantiation of the shape and parameters of a new sorting device for granular materials. It was substantiated the relevance of the new device, which has a great importance for mechanical engineering and agricultural production. A mathematical model for sorting granular materials is proposed. The shape, design parameters and modes of operation of various elements with different: sorting assortment and efficiency indicators were substantiated taking into account the relevance of the device. For this purpose, a new auger sorting device was developed. It was equipped with various automation devices to increase productivity. The satisfactory results were obtained. This sorting device, equipped with an automatic regulator, received a patent from the Copyright Agency of Azerbaijan Republic. The proposed device does not create conditions for pollution of the production area, it has competitive advantages and high rates of technical and economic efficiency.

The shutter-automatic machine throughput of the washing device of the water level automatic regulator

To determine the throughput of the automatic gate of the flushing device, which is part of the hydraulic automatic water level controller with flexible working bodies, developed by the author together with Ya.V. Bochkarev, experimental studies were conducted. They were carried out by the method of physical modeling of the model and nature on an experimental installation, with the installation of two models of an automatic shutter: a) with a fixed angle of inclination of the pressure board, b) with an automatic shutter in the form of a container consisting of a rigid board under pressure in front of it and a rubberized fabric, as part of an automatic water level regulator. Based on the results of these studies, formulas and dependencies were obtained to determine the flow rates without taking into account and taking into account the lateral outflows and lateral compression coefficients and the water flows passing through the automatic gate.

RESEARCH OF THE AUTOMATIC REGULATOR OF THE INPUT VOLTAGE STABILIZER OF AN AUTONOMOUS INVERTER

This article presents the results of the study of the automatic regulator of the stabilizer. In the work, the study of the output voltage of an autonomous inverter was carried out by introducing a digital form of setting the insert of a stabilized voltage and a digital form of comparison with a reference voltage. The achieved high accuracy of voltage stabilization does not depend on the choice and careful adjustment of the elements. This made it possible to achieve stability of the voltage generator and the width of the sensitivity zone. The voltage regulation of the converter is carried out by changing the level setting associated with the shift of the insensitivity. The speed of development of a given control angle depends on the pulse repetition rate of the generator, which is limited only by the frequency properties of integrated circuits. Improvement of the control system of the autonomous inverter made it possible to increase the accuracy of stabilization of the output voltage of the inverter, which made it possible to simplify the adjustment of the control system for easy coordination with other software elements. Studies have shown that the voltage regulation of the converter is carried out by changing the level setting associated with a shift in the dead zone. The speed of development of a given control angle depends on the pulse repetition rate of the generator, which is limited only by the frequency properties of integrated circuits. And with the equality of the frequencies of the pulse generators, the minimum width of the dead zone and the change in the load from nominal to no-load, the stabilization accuracy of the output voltage of the inverter was 0.5%.

FEATURES OF STRENGTH TESTING OF PASSENGER WAGON AUTOMATIC REGULATORS

The automatic regulator РКЗТ-675 (РТПР-675) and РТПР-675M is installed in the brake lever transmission of the passenger car and used for automatical maintenance of gaps between the surfaces of rolling of wheel pairs and brake pads within the established limits irrespective of the wear of the rolling surfaces of wheels. The design of auto regulators allows you to change the stroke of the piston rod and the brake cylinder and to manually release and tighten the regulator. Scope of auto regulators: freight, passenger cars and electric trains of the main railways. The article is devoted to solving the problem of contradictions in clause 15.5.7 of the current departmental Ukrainian instruction ЦЛ-0013 for repairing brake equipment of the railway carriage of the existing requirement for mandatory compliance with screw unscrewing in size "a" within 300-350 mm when testing automatic regulators on an automatic test stand for strength under load a normalized force of 8t in the longitudinal direction, provided that there are no residual deformations of the automatic regulator screw along its length. The article aims to refute the dependence of the values of the stress state of an automatic regulator when testing its strength on a test bench from a change in its length in the entire possible range of screw unscrewing by size "a" in the allowable range of 0-600 mm. The problem is solved by calculation using two different methods, and the results of the stress state values of the automatic regulator with different lengths of screw unscrewing by size “a” are compared with each other. Based on this, the general conclusion is made that the size “a” (within the range of 0–600 mm) of the automatic regulator screw unscrewing when testing it for strength with the same load force (N = 8t ≈ 80 кН) in the longitudinal direction does not affect the calculated value of the screw tension σ = 113.23 MPa when tested on an automatic bench. The developers of the departmental Ukrainian instruction ЦЛ-0013 are invited to make in clause 15.5.7 corresponding changes regarding the requirement of optional observance of the value of the size "a" within 300-350 mm at the bench test of the automatic regulators for the tensile load under the standardized force of 8t.

Using Real World Data in Virtual Development and Testing of a Path Tracking Controller for an Autonomous Vehicle

The article describes an approach to development and testing of a path tracking function for an autonomous vehicle. The essence of the approach consists in combining experimental data and mathematical modeling in order to simulate operation of a path-tracking regulator in real world maneuvers. The procedure can be divided into two stages. The first one implies field-testing of the vehicle under control of a human driver with logging of the essential dynamic variables including the driving trajectory. Then the obtained data is used to validate the model of vehicle dynamics being a tool for further simulations. At the second stage, a simulation is performed with tracking of the previously logged trajectory by an automatic regulator. The results of these steps allow for comparison between the human and automatic controls with assessment of pros and cons of the latter and the ways of improving its performance. The proposed approach was implemented within a research and development project aimed at building of an experimental autonomous vehicle. The article describes the obtained results as well as the experiments and the mathematical model used for implementation of the said approach.