Computationally two-dimensional finite-difference model for hollow-fibre blood-gas exchange devices.

ABSTRACT

The goal of this research is to develop a predictive model with good absolute accuracy for blood-gas exchange devices. The proposed model, unlike existing models, is able to predict gas transfer to blood flowing outside oxygenating fibres without experimental data. The proposed model uses a finite-difference numerical technique to solve computationally two-dimensional gas exchange problems such as gas transfer to blood outside hollow fibres. The model is compared to bovine and human experimental data from the small test cells with microporous polypropylene fibres. The test cell flow rates range from 1 m litre min-1 to 5 m litre min-1 for a 72-fibre device. Shear-augmented oxygen diffusion appears to be present, although good accuracy is obtained with a nonaugmented diffusion model, particularly at lower flows. The maximum deviation of oxygen saturation predicted by a shear-augmented bovine blood model from the experimental regression line was 1.7 per cent.