Development and Validation of a Brain Phantom for Therapeutic Cooling Devices

Abstract

Tissue cooling has been proven as a viable therapy for multiple conditions and injuries, and has been applied to the brain to treat epilepsy and concussions, leading to improved long-term outcomes. To facilitate the study of temperature reduction as a function of various cooling methods, a thermal brain phantom was developed and analyzed. The phantom is composed of a granular hydrogel through which is circulated 37 degree water, representing blood perfusion. The phantom was tested in a series of cooling trials using a fluid-cooled cooling block during which the perfusion rate was varied. Results were compared against a validated finite difference (FD) model. The model was used to calculate steady state cooling at a depth of 5 mm for all flow rates, for both the phantom experiment and a model of the brain. The FD phantom model showed good agreement with the empirical phantom results. Furthermore, the empirical phantom agreed with the predicted brain response within 3.5% at physiological flow, suggesting a biofidelic thermal response. The phantom will be used as a platform for future studies of thermally-mediated therapies applied to the cerebral cortex.