Application of Spectral Imaging Technology to a New Non-invasive Visual Diagnostic Method

一种独立于光源的色彩再现系统已被开发用于医学的实际应用，并由一组不同专业的医疗保健专业人员主观评估其性能。对于医学诊断，存档病变皮肤的图像数据，以便直观地回顾其时间变化是很重要的。然而，为实现这一目的，从未开发出足够的色彩再现质量。首先，对某大学医院各地点的光源条件进行了测量，发现医院使用的光源颜色范围广，其中一些光源的显色指数（Ra）值过低，无法进行普通的比色法显色。因此，采用多光谱成像技术进行与光源无关的色彩再现，对各种光源的色彩进行自适应校正。医疗保健专业人员组通过将图像与真实皮肤进行比较来评估再现的皮肤颜色。结果验证了所开发系统的有效性，并揭示了除平均色彩再现外，医学上对阴影再现的需求。在那之后，开发了一个原型系统。该系统将普通三波段相机捕捉到的皮肤颜色转换为实际的皮肤颜色，而不考虑光照条件，同时实时显示黑色素、血红蛋白和氧合血红蛋白的分布。预计它将激发广泛的医学应用研究活动。

A system of illuminant-independent color reproduction has been developed for practical use in medicine, and its performance was subjectively evaluated by a group of healthcare professionals of various specialties. For medical diagnosis, it is important to archive image data of diseased skin for the purpose of visually reviewing its chronological changes. However, sufficient color reproduction quality has never developed for this purpose. First, the illuminant conditions at various locations in a university hospital were measured and it was found that illuminants used in the hospital have a wide range of colors and that some of them have color rendering index (Ra) values that are too low for ordinary colorimetric color reproduction. Therefore, the multi-spectral imaging technique was applied for the illuminant-independent color reproduction to correct the color adaptively to the various kinds of illuminant. The healthcare professionals group evaluated the reproduced skin color by comparing the images with real skin. The results verify the effectiveness of the developed system and also expose the medical need for shading reproduction in addition to averaged color reproduction.After that, a prototype system was developed. That system translates color of skin captured by an ordinary three band camera to that of an actual one regardless of the illuminating conditions and simultaneously visualizes distribution of melanin, hemoglobin and oxyhemoglobin in real time. It will be expected to inspire a wide range of research activities for medical application.