A portable illumination device for photodynamic therapy of the oral cavity

Photodynamic therapy (PDT) is a minimally invasive method for treating oral leukoplakia. In this paper, we propose a portable PDT device consisting of a flexible circuit board with a liquid flow cooling module on the back. The light source size was 17mm×11mm×4mm×11mm×4mm, and the irradiation area of the light source was up to 100mm2. The irradiance range of this device was from 10mW/cm2 to 100mW/cm2. Simulation and experimental results showed that the irradiance coefficient variation for a treatment area of 81mm2 was less than 7%. At an irradiance of 100mW/cm2, a device surface temperature of lower than 42∘C can be achieved to satisfy the safety requirements under the conditions that the temperature of cooling liquid is 10∘C and the liquid flow speed is above 12mL/min.