Transurethral ureteral lithotripsy (TUL) is a treatment that breaks stones by irradiating a pulsed laser through an optical fiber. Heat and impulsive force of the laser may affect nearby tissues during treatment. A bu...Transurethral ureteral lithotripsy (TUL) is a treatment that breaks stones by irradiating a pulsed laser through an optical fiber. Heat and impulsive force of the laser may affect nearby tissues during treatment. A bubble induced by the pulsed laser plays an important role in laser lithotripsy. It is important to understand effects of the bubble on the surroundings by simulating treatment in a narrow space such as in a ureter. In this study, we observe behaviors of the bubble in the narrow space inside a soft material simulating under <em>i</em><em></em><em>n vivo</em> condition. The bubble formed under various laser irradiation conditions exhibits characteristic behavior, and the surrounding elastic wall is compressed and bulged when the bubble grows and collapses. In the case of bubble formed near the elastic wall, the bubble contacts with the elastic wall during growth, and severe large deformation of the elastic wall is observed at bubble collapse. According to the temperature measurement, a temperature rise of 25<span style="white-space:nowrap;">℃</span> - 30<span style="white-space:nowrap;">℃</span> occurs in the area where the bubbles are in contact. From the above, by presenting the deformation of the elastic wall and temperature increase, we can show useful information to improve the safety for treatment at narrow space.展开更多
The holmium:YAG (Ho:YAG) laser is effectively used for transurethral ureterolithotripsy. The laser is applied through an optical fiber in a ureter. A bubble is formed by a laser irradiated from the fiber tip and a cal...The holmium:YAG (Ho:YAG) laser is effectively used for transurethral ureterolithotripsy. The laser is applied through an optical fiber in a ureter. A bubble is formed by a laser irradiated from the fiber tip and a calculus is crushed by the impact of the bubble collapse. In this study, we observed the characteristic behavior of a bubble induced by a Ho:YAG laser near a wall surface, using a high-speed video camera. Furthermore, we measured the forces of a bubble collapse using an impulsive force sensor. As a result, we showed characteristic bubble collapse behavior and impulsive force distribution for various fiber placement conditions.展开更多
文摘Transurethral ureteral lithotripsy (TUL) is a treatment that breaks stones by irradiating a pulsed laser through an optical fiber. Heat and impulsive force of the laser may affect nearby tissues during treatment. A bubble induced by the pulsed laser plays an important role in laser lithotripsy. It is important to understand effects of the bubble on the surroundings by simulating treatment in a narrow space such as in a ureter. In this study, we observe behaviors of the bubble in the narrow space inside a soft material simulating under <em>i</em><em></em><em>n vivo</em> condition. The bubble formed under various laser irradiation conditions exhibits characteristic behavior, and the surrounding elastic wall is compressed and bulged when the bubble grows and collapses. In the case of bubble formed near the elastic wall, the bubble contacts with the elastic wall during growth, and severe large deformation of the elastic wall is observed at bubble collapse. According to the temperature measurement, a temperature rise of 25<span style="white-space:nowrap;">℃</span> - 30<span style="white-space:nowrap;">℃</span> occurs in the area where the bubbles are in contact. From the above, by presenting the deformation of the elastic wall and temperature increase, we can show useful information to improve the safety for treatment at narrow space.
文摘The holmium:YAG (Ho:YAG) laser is effectively used for transurethral ureterolithotripsy. The laser is applied through an optical fiber in a ureter. A bubble is formed by a laser irradiated from the fiber tip and a calculus is crushed by the impact of the bubble collapse. In this study, we observed the characteristic behavior of a bubble induced by a Ho:YAG laser near a wall surface, using a high-speed video camera. Furthermore, we measured the forces of a bubble collapse using an impulsive force sensor. As a result, we showed characteristic bubble collapse behavior and impulsive force distribution for various fiber placement conditions.
