Device for measuring the blood oxygenation considering the concentration of carboxyhemoglobin

The general method of assessing the level of arterial blood oxygenation is pulse oximetry. However, in known pulse oximeters, blood oxygen saturation is determined only by functional fractions of hemoglobin, reducing the accuracy of the devices and is unacceptable in some clinical cases. The purpose of the study was to increase the accuracy of measuring the arterial blood oxygenation level by the pulse oximetric method by considering the concentration of carboxyhemoglobin and developing a device. To achieve this purpose, the authors used Simulation computer modelling methods to build a model and assess the accuracy of a pulse oximeter. The purpose was achieved by using an additional LED. Its light wavelength choice was justified under the condition of maximizing the contribution of carboxyhemoglobin to the optical density of the measurement object. The theoretical provisions for measuring the blood oxygenation level, considering carboxyhemoglobin concentration and the structural diagram of the pulse oximeter, have been developed. Computer models of the known pulse oximeter and pulse oximeter with an additional LED were developed, simulation studies were conducted based on the developed models, and the device accuracy for measuring blood oxygenation level, considering carboxyhemoglobin concentration, was evaluated. The authors conclude that simulation studies based on the developed models proved that the proposed pulse oximeter, unlike the known one, allows you to detect and evaluate the decrease in blood oxygenation level caused by an increase in the concentration of carboxyhemoglobin in the patient's blood.