Data Analysis and Related Applications, Volume 1

23The Correlation Between Oxygen Consumption and Excretion of Carbon Dioxide in the Human Respiratory Cycle

General anesthesia and lung damage treatment in novel coronavirus infection and other diseases with mechanical ventilation often require strict monitoring of oxygen delivery (DO₂) and consumption (VO₂), as well as CO₂ exhalation rate (VCO₂). Oxygen transport consistency can be easily monitored in real time by means of percutaneous pulse oximetry via the level of blood oxygen saturation in pulsatile flow (SpO₂). The method is based on the difference of absorbed light wavelength by the blood in red and infrared parts of the spectrum, dependent on the number of O₂ molecules captured by hemoglobin. The control of the O₂ content in the inhaled and exhaled air, and the respiratory removal of CO₂ can be carried out using paramagnetic or fuel cell and infrared absorption sensors, respectively. Acoustic, thermal, magnetic, ionization and other types of gas analyzers based on the change in the relevant properties of the measured gases, depending on their concentration in the mixture, are also used. The algorithm for real-time VO₂ and VCO₂ measurements includes the numerical integration of dVO₂/dt and dVCO₂/dt instantaneous values during respiratory cycle, derived from the product of certain gas concentration and total flow instantaneous values. The report discusses such an approach, emphasizing (i) precision gas concentration and flow signal synchronization and (ii) taking into ...