Non-Fourier bio heat transfer modelling of thermal damage during retinal laser irradiation

Study of non-Fourier energy transport is important in various biomedical applications, in the understanding of heat transfer in biological tissues. One such biomedical application that involves non-Fourier heat conduction is laser irradiation of the retina, where a high heat flux is typically applied for a short period of time. In the present study, retinal laser irradiation is analysed using the dual phase lag model for heat conduction. A simplified one-dimensional model of the human eye with seven layers is used in the simulation. The laser heating is modelled as a volumetric heat source and the respective magnitudes are calculated based on the absorptivities of the various layers. Apart from the temperature distribution, the damage distribution is also computed using the Arrhenius damage integral approach. The effect of the two phase lags τq and τT on the temperature and damage distributions are analysed. Small τT/τq ratios (⩽0.01) indicate a thermal wave like behaviour, which diminishes as the ratio increases (i.e. for τT/τq ⩾ 0.1). The results are also compared with corresponding results from the Fourier model. Choroidal blood perfusion rate is found to have no significant effect on the unsteady temperature and damage distributions.