Mathematical Modelling of Carbon Dioxide Exchange in Hollow Fiber Membrane Oxygenator

Abstract

The main objective of this study is to simulate the carbon dioxide (CO2) blood-gas exchange in membrane oxygenator, evaluate the effect of sweep gas flow rate on CO2 partial pressure (pCO2) and to determine the response of pCO2 to the step change of sweep gas flow rate. In extension to the simulation of gas transfer in membrane oxygenator, open-loop response on sweep gas flow rate was applied to the developed mathematical model to prove its effect on CO2 removal rate. Three sweep gas flow rates were set, i.e. 1 L/min (Qg/Qb = 0.5), 2 L/min (Qg/Qb = 1) and 4 L/min (Qg/Qb = 2) and the simulated pCO2 in artery was observed. Next, one-way ANOVA test was performed to determine the significant difference in CO2 removal rate between these gas flow rates. For the next test, sweep gas flow rate was changed at t = 60 second and t = 120 second of simulation, to evaluate how pCO2 will response to the step change of gas flow rate. As the result, the highest CO2 removal observed when Qg/Qb = 2, as compared to gas-blood ratio of 1 and 0.5. The ANOVA test also proved the significant difference in simulated pCO2 for each flow rate. For the last test, a proportional response of pCO2 towards the change of sweep gas flow rate was highlighted. In conclusion, the rate of CO2 removal from blood can be manipulated by sweep gas flow rate and this rate can be adjusted to achieve the optimum performance of membrane oxygenator for CO2 sequestration.