Thermal Analysis of Human Eye for Biomedical Applications

Thermal analysis of the human eye using finite element analysis is a very useful tool to predict the outcome of medical treatment without the need for in-vivo or invasive laboratory experiments. In this research work, a three-dimensional thermal model of the human eye was generated for two biomedical applications. First, we studied the thermal response of the eye under operating an intraocular projection prosthesis device to treat corneal opacity. Based on the simulation result, the power budget of the device was established such that the temperature elevation in the living tissues satisfied the limit imposed by the international standard for implantable devices. The second application involved simulations of localized hypothermia treatment to prevent retina ischemia using a sclera cooling ring device. The simulation result showed that the cooling ring device can effectively reduce the temperature of the retina and optic nerve head to a therapeutic temperature range within the desired timeframe. The thermal models used for the analysis includes conduction, convection, and radiation thermal processes. Evaporation of the tear film from the eye and convection flow of aqueous humor were also considered in developing the thermal model. A realistic thermoregulating blood flow model was introduced that considers eye tissue, inflowing blood, and outflowing blood as three phases of a porous media. Sensitivity analysis was performed on all the parameters of the thermal model, which included material properties, and thermal and blood perfusion parameters. A model validation was also carried out using five pig eye models. The validation result showed that the thermal response of the pig eye models matched very closely to the in-vitro result.