Handheld optical coherence tomography device for photodynamic therapy

Photodynamic therapy （PDT） is a very effective treatment for port wine stains （PWS）. To guide and assess PDT treatment, a handheld optical coherence tomography （OCT） probe was designed for real-time imaging of the PWS patient. The system uses a light source with a center wavelength of 1310 nm, -3 dB bandwidth of 90 nm and an optical power of 9 mW. The system also has a spatial resolution of 8 μm （lateral）× 7μm （axial）, an imaging rate of 4 frames per second, and a 102 dB sensitivity. We then demonstrate that the OCT imaging system can clearly distinguish between normal and PWS tissues. Therefore, the system can provide valuable guidance for PDT treatment.