[Diagnosis of urinary disorders using ultra-thin ultrasound probe]

We have developed a new diagnostic instrument, to visualize small or early lesions from inside by introducing a flexible ultra-thin probe (2 mm in diameter) into the urinary system. The frequency of the oscillator is 20 to 30 MHz, so the tomogram obtained by the method is extremely fine compared with the ultrasonogram obtained by the scanning from outside of the body. Three-dimensional reconstruction of tomogram is also realized. This display method is valuable to plan operations, follow the progress of therapy, and obtain well informed consent from the patient. We are now developing systems to bend and twist the tip of the intraureteral probe. They are applications of shape memory alloy, thermo-electric actuator and magnetic torque.