Controlled photothermal therapy based on temperature monitoring: theoretical and experimental analysis

Real-time monitoring and temperature-based control are beneficial for optimizing the outcomes of thermal ablation treatments. In this paper, simulations and experiments were performed to investigate the efficacy of the temperature-feedback control system in confining the thermal damaged area and in maintaining the setpoint temperature. The implemented control system adjusts the laser source power based on the maximum temperature values measured by fiber Bragg grating sensors. The theoretical model predicts the thermal response of the biological tissue under different control parameters and allows calculating the produced thermal damage. Different setpoint temperatures ranging from 43 degrees C to 60 degrees C were chosen to evaluate their effects on the irradiated tissue region, in terms of temperature trend and thermal damage. The numerical results are validated by the experimental temperature trends obtained applying the same control strategy. Finally, both the simulation results and experiment outcomes show the capability of the control system to confine the tissue thermal damaged area by performing a laser ablation procedure almost at the set temperature.