Exposure inhomogeneity from Am and Sr/Y sources in terms of the eye lens monitoring in the nuclear facilities

Yoshitomi, Hiroshi; Kowatari, Munehiko

Radiation Protection Dosimetry, 188(2), p.191 - 198, 2020/02

https://doi.org/10.1093/rpd/ncz275

Composite-type optical fiberscope for laser surgery for twin-to-twin transfusion syndrome

Oka, Kiyoshi; Naganawa, Akihiro*; Yamashita, Hiromasa*; Nakamura, Tetsuya*; Chiba, Toshio*

Lecture Notes in Computer Science 5128, p.251 - 259, 2008/00

We present our new laser device for prospective human fetoplacental surgery including that of twin-twin transfusion syndrome. We developed acomposite-type optical fiberscope (2.2-mm in diameter) that enables transmission of 40-W Yb fiber laser light alongside of coaxial fetoscopic images. Using a laser condensing lens on the fiberscope tip, Yb fiber laser light can be focused 10-mm off. Using porcine liver tissue, despite changes in delivered laser energy, the diameter and depth of cauterized areas remained constant when the liver position agreed with the laser focal point, although the laser output altered the extent of tissue ablation. In conclusion, the performance of the fiberscope can be well controlled with accurate and efficient ablation of the target tissue. This Yb fiber laser fiberscope is expected to work much better if mounted on a miniature bending manipulator and if provided with additional functions (realtime distance and blood flow measurements).