Inspection of skin hemodynamics with hyperspectral camera.

Using hyperspectral imaging techniques, which enable us to simultaneously obtain spatial and wavelength information, we have improved upon the newly developed hyperspectral camera to develop a method of observing changes in skin melanin levels and hemodynamics over time. As an evaluation of this method, we measured the skin diffuse reflectance spectrum of the human middle finger in an experiment of blood flow blockage in the brachial region. The changes in skin hemodynamics observed through this method match the behavior expected based on clinical knowledge, and also show an extremely high correlation with results obtained by the Erythema Index, which is used to make similar calculations from a limited number of wavelengths.

A novel robotic laser ablation system for precision neurosurgery with intraoperative 5-ALA-induced PpIX fluorescence detection.

We developed a combined system of tumor detection by 5-ALA-induced PpIX fluorescence and precise ablation by micro laser for the first time, with an automatic focusing and robotic scanning mechanism for the brain surface. 5-ALA accumulates on tumors to be metabolized to become PpIX that is a fluorescent. Intra-operative detection of 5-ALA induced PpIX fluorescence provides useful information for tumor detection. The wavelength of the micro laser is 2.8 microm close to the absorption band of water. This laser is effective only on the surface of brain tissue, enabling precise ablation at the boundary between tumor and normal tissue identified by intra-operative 5-ALA induced fluorescence. Combination tests of the fluorescence measurement and the laser ablation were performed, and it was possible to extract the area with fluorescence appropriately from the measurement data, and the micro laser with automatically scanning selectively ablated the extracted area.