Numerical model for predicting and managing heat dissipation from a neural probe

Use of stimulating neural probes has increased in an effort to better understand neural pathways. Current designs using light as a stimulating impulse externally couple the light into the probe. Relocating the light source to the probe tip would improve the flexibility of the technique; however, this approach would generate heat within the embedded probe. Minor temperature excursions can easily damage tissues under study, creating inaccurate results and/or damaging the tissue. A model has been created using COMSOL for the thermal effects of these heated probes in the brain. The model includes blood perfusion and metabolic processes. The model was used to investigate the effect of different geometric parameters on the temperature excursion. It was observed that the maximum temperature change decreases with insertion depth and decreases as the heated area of the probe is increased. The model was also used to study the effect of extending the probe beyond the heated region. This resulted in a significant reduction in temperature excursion. The model has been experimentally validated through physical tests using an Agar gel as a neural tissue simulant.