Abstract
Purpose. The GaN-based ultraviolet laser diode (UV-LD), which has recently became commercially available, was used to study the autofluorescence (AF) of human bronchial tissue. The conventional AF measurement system uses a large excitation light source, and the measured data have problems associated with the intermixing of the excitation source and the AF signal. The wavelength of the UV-LD is much shorter than that of the He-Cd laser which is employed for the LIFE system, and the AF measurement is performed without interference of the excitation light using the UV-LD. AF data were compared with those obtained using the He-Cd laser. Method. The spectroscopic analysis of the AF was performed for 13 resected specimens of the human bronchus using the UV-LD. The relationship between the origin of the AF signal and the histopathological structure was also studied. Result. The AF characteristics were similar to those obtained using the He-Cd laser or the xenon lamp. Blue AF, the peak wavelength of which was at around 483 nm was additionally observed from normal tissues. The spatial distribution of the AF signal intensity revealed that a strong AF signal obtained from the region where the high density of the elastin was confirmed. Conclusion. The AF measurement in a wide wavelength region can be easily performed by using the UV-LD as the excitation light source.
