In the Transurethral ureteral lithotripsy using flexible ureteroscope (f-TUL), the endoscope is inserted in the urethra and the kidney, and calculuses are broken by irradiating the laser from the optical fiber in the channel. In this research, in order to improve operability when changing the laser irradiation position, a device capable of finely adjusting the irradiation position within the field of view of the endoscope by mounting an active bending mechanism using shape memory alloy (SMA) wires on the optical fiber was developed.

In this study, a bending mechanism with an outer diameter of 0.92 mm and a controller using foot switches were fabricated. Evaluation was made using the renal pelvis and calix model and the endoscope. This bending mechanism was able to bend in three directions around the tip of the endoscope, and it was able to bend in the direction of pseudo 360° by rotating the device. Also, even when the endoscope was interfered by the model and could not be irradiated, irradiation was able to be performed by driving the bending mechanism.