Modelling of Heat Transfer Processes in Heat Exchangers for Cardiopulmonary Bypass

Valentyna Danilova,Nikolaj Višniakov,Vitalii Kotovskyi,Andžela Šešok,Vladyslav Shlykov

doi:10.3390/math9233125

Abstract

A model of the heat exchange process in the heat exchanger of the cardiopulmonary bypass device is proposed which allows for automation of the process of temperature regulation in the cardiopulmonary bypass with an accuracy of ±1 °C during cardiac surgery under controlled cooling and warming of the patient’s heart and brain. The purpose of this research is to create a concept and model of the temperature control circuit using the MSC Easy5 system, the creation of mathematical models of blocks of the temperature control circuit, and the description of the principle of temperature control in the cardiopulmonary bypass circuit. The model of the temperature control loop in the heat exchanger of the heart-lung machine was created using the MSC Easy5 system with a programmable microcontroller. The microcontroller implements a specialized temperature control algorithm in the C language. The model allows the creation of a full-fledged virtual prototype of a temperature control device in a heat exchanger, and helps to conduct virtual tests of the developed device at the design stage. The model identifies control system flaws and influences decisions made before producing an official prototype of the product.

Highlights

The heart-lung machine has been used in open-heart surgery for over 60 years
The use of artificial blood circulation marked the beginning of an era of modern cardiac surgery, as it became possible to stop the heart and perform open-heart surgery
Mathematical models in the MSC Easy5 system are implemented for the heart-lung machine‘s heat exchanger in the form of a temperature control circuit in the heart-lung machine with a temperature control accuracy of ±1 ◦ C

Summary

Introduction

The use of artificial blood circulation marked the beginning of an era of modern cardiac surgery, as it became possible to stop the heart and perform open-heart surgery. The function of this device is to pump the patient’s blood and saturate it with oxygen. Body temperature is reduced by cooling the blood in a heat exchanger to reduce tissue oxygen consumption and protect organs from hypoxia. The heat exchanger is used in the extracorporeal membrane oxygenation ECMO circuit for a cardiopulmonary support procedure to cool and warm the blood [3]

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