Characteristics of rising temperatures through laser irradiation using a temperature sensor integrated optical fiber probe for soft tissue ablation

Abstract

A new structure composed of silica optical fibers for soft tissue ablation is proposed and fabricated in this study. Laser irradiation and temperature monitoring are simultaneously performed using a wavelength-division multiplexing technique with a single optical fiber probe. A 1.55-μm wavelength range light is used for temperature measurement. The fabricated Fabry–Perot interference temperature sensor comprising a glass capillary and a graded-index multimode fiber exhibits good temperature sensor characteristics. The probe end is terminated with a glass capillary having a declined glass cap. This portion suppresses the reflected light backward to the incident fibers. Because the reflected light at this portion does not affect the interference of internal reflected light, regardless of the outer medium, stable temperature measurement is confirmed. A 1.48-μm laser irradiation method is investigated as a thermal source for soft tissue ablation. The characteristics of rising temperatures through laser irradiation of chicken-breast meat are investigated and indicate sufficient temperature increases for thermal ablation of soft tissue. A good estimation of the thermal protein denaturation region is achieved through a simple analytical equation using the measured value at the fiber tip temperature sensor.