SU848031A2 - Thermoregulating device for artificial circulation apparatus - Google Patents

Description

(54) THERMAL REGULATORY DEVICE FOR MACHINES OF ARTIFICIAL BLOOD CIRCULATION

one

The invention relates to medicine and is intended to ensure the thermoregulation of the body of a person or an animal by heating or cooling the blood during cardiopulmonary bypass.

According to the main author. St. No. 538713, a device for smooth control of the temperature gradient between blood and heat carrier is known, in which only a metered connection of the circuits of the heated and cooled heat carrier entering the heat exchanger Tlj is provided.

almost always, different hydrodynamic characteristics (hydroresistances) of pre-filled circuits in the process of mixing the coolants between them there is some volumetric redistribution of the coolant;

The indicated redistribution of the coolant creates a noticeable drop in the level in one of the tanks for its preparation (with a simultaneous increase in

pressure in another), changes the position of this level relative to temperature sensors and energy components (electric heaters and evaporator), changes the actual response thresholds of the thermal control system of the heat carrier, significantly increases the error of its operation, causing the outputs to off-design modes

10 work. At the same time, after completion of surgical intervention on the heart, for example, in cases of prosthetic aortic valve, after isolated hypothermic coronary perfusion 15, carried out simultaneously with general normothermia, it is necessary to have a smooth, stepwise warming of the coronary bed with an accuracy of maintaining the temperature to 0 5-lc. therefore

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The above-mentioned errors can cause abnormal vascular reactions, as well as cavitation with the formation of small bubbles in the perfusate, threatening the embolism of the heart vessels

25 and the brain.

Claims (1)

The purpose of the invention is to improve the accuracy of the coincidence of the true and reduced temperature of the coolant circulating in the device, as well as increase the convenience of its operation. The goal is achieved by the fact that in a thermo-regulating device for heart-lung machines with a holding heat carrier preparation unit with tanks for heating and cooling of the neck are provided with float plugs, a system for automatic and manual control and adjustment of heat carrier parameters, a remote control and a circulation system consisting of two circuits, each of which has a tap to the control valve for the circulation of the heat carrier of the other circuit, the upper parts of the heating and cooling tanks They are interconnected by two parallel pipelines, each of which is equipped with a check valve. The drawing shows the functional diagram of the device. The device contains a heating tank 1, a heat carrier preparation unit 2 which contains electric heaters 3, a thermometer 4 electrical contact, a filler neck with a float plug 5, a level gauge b, a thermal insulation sleeve 7 with a casing 8, a temperature sensor 9. The tank 1 is supplied with pipes 10 and 11 of supply and return of the coolant through the pump 12. The cooling tank 13 contains the evaporator 14 of the cold unit 15, the meter 16 is electrocontact, the filler neck with the float plug 17, the level gauge 18, the thermal insulation jacket 19 with the housing 20, the sensor 21 temperature The tank 13 is supplied with pipelines 22 and 23 for supply and return of the coolant through the pump 24. Both tanks of the unit 2 communicate with each other by two parallel lines 25 and 26, each of which has non-return valves 27 and 28. The valves are set with their own opposite directions each other (drawing) "Unit 2, including tanks 1 and 13, communicates with blood heat exchangers 29 and 30 via remote control 31, in block 32 of which there are taps for controlling the flow of coolant (including mixing taps for the heat sink), auto blocks iki termoregu lation heat transfer fluid in both circuits, Elektrotermometriia arrow showing the actual temperature and a predetermined heat transfer fluid circuit in each of two points (in the tank and at the outlet of the heat exchanger). Automation units and electrothermometers are not shown in the drawing. When the thermostatting device is operating in the mixing modes of the heat carriers of both circuits in tanks 1 and 13, the pressure of the heat-transfer agent never rises above what the valves 27 and 28 are adjusted to (usually 0.15-0.25 atm). Low pressure limits the deformations of the walls of the tanks and elastic tubes and, therefore, limits the volume of redistribution of the coolant between the circuits. Thus, the change in the level of the coolant in the tanks 1 and 13 relative to the thermostat elements (thermometers 4-16, temperature sensors 9 and 21, electric heaters 3 and the evaporator 14J) is very small. As a result, very small values of the coolant flow through the tank from the tank to the tank reflected on the temperature of the coolant circulating through the blood heat exchanger, since the energy capabilities of the heating and cooling systems are large enough. Therefore, the accuracy of the match between the true and the set temperature of the heat carrier increases. Formula of the Invention Thermostatic device for the cardiopulmonary bypass device according to St. St. 538713, characterized in that, in order to improve the accuracy of matching the set and true temperature of the heat transfer fluid, the open parts of the heating and cooling tanks are interconnected by two parallel pipelines , each of which is equipped with a check valve. Sources of information taken into account during the examination 1. USSR author's certificate hf 538713, cl. A 61 M 1/03, 1974.