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
We report the observation of bubble generation and migration in a germanate g/ass during irradiation by a femtosecond laser of high repetition rate. Bubbles are formed around the focal area of the laser beam, and thei...We report the observation of bubble generation and migration in a germanate g/ass during irradiation by a femtosecond laser of high repetition rate. Bubbles are formed around the focal area of the laser beam, and their movement indicates the presence of thermal gravity convection in the glass melt, which is beyond the existing theoretical model about temperature l^eld of focal area. Inside the bubbles, oxygen molecules are observed by the con focal Raman micro-spectroscopy. The generation of molecular oxygen and bubbles is explained in terms of the spatial separation of Ge and 0 ions and micro-explosion inside the glass melt.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.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51132004 and 61475047the National Basic Research Program of China under Grant No 2011CB808100+2 种基金the Natural Science Foundation of Guangdong Province under Grant No S2011030001349the Fundamental Research Funds for the Central Universities under Grant No 2013ZM0001the Open Fund of the State Key Laboratory of High Field Laser Physics of Shanghai Institute of Optics and Fine Mechanics
文摘We report the observation of bubble generation and migration in a germanate g/ass during irradiation by a femtosecond laser of high repetition rate. Bubbles are formed around the focal area of the laser beam, and their movement indicates the presence of thermal gravity convection in the glass melt, which is beyond the existing theoretical model about temperature l^eld of focal area. Inside the bubbles, oxygen molecules are observed by the con focal Raman micro-spectroscopy. The generation of molecular oxygen and bubbles is explained in terms of the spatial separation of Ge and 0 ions and micro-explosion inside the glass melt.
