Development of a quick in -vivo sensing system based on fiber-optics for cancer diagnostics at very early stage

众所周知，在癌症发展的初始阶段，一些特定类型的酶，如细胞色素P450 1A，往往与致癌物产生dna -致癌物加合物起重要作用，作为癌症发展的起始。事实上，可以理解的是，这种酶的诱导本身可能是癌症风险较高的一个显著指标。因此，我们提出了一种基于酶活性信息的癌症诊断新方法。从医学的角度来看，如果癌症诊断能够在癌细胞产生之前的早期阶段进行，这可能是非常宝贵的。在基金资助的2003 -2004年研究期内，我们致力于光纤传感系统的开发，以实现癌症诊断的新方法。通过这项工作，成功完成了快速（诊断治疗消耗时间短）、体内（直接适用于人体脱脂）的系统。该系统利用一对光纤通过光学技术，利用酶反应产生的荧光物种来检测目标酶的活性；一个用于传递激发光源，另一个用于将信号光引导到高灵敏度的光电探测器。酶的活性越高，则发光功率增加曲线的斜率越陡，因此可以从光纤传感器输出处的荧光功率变化来评价。由于其直径小，柔韧性好，塑料光纤被用作光纤传感器，因此它允许我们访问身体的任何地方。然而，我们发现，传感器头部与待测物体之间的空间在Immseparation时存在最佳条件。综上所述，新型癌症诊断方法的非接触式操作目前在技术上是可行的，我们计划继续研究将光纤传感器系统实际应用于真正的医学癌症诊断。

It is well know that at the initial stage of cancer development, some particular types of enzyme such as cytochrome P450 1A often act an important role with carcinogens to produce DNA-carcinogen adducts, as initiation of cancer development. In fact, it is understood that the induction itself of such type of enzymes maybe a remarkable indication of higher cancer risk condition. We have thus proposed anew method of cancer diagnostics based on the information of enzyme activities. It maybe invaluable on medical point of the view if cancer diagnostics can be done at very early stage before arising cancer cells.In the research term of 2003 -2004 of the grant, we have paid our efforts to the development of a fiber-optic sensing system in order to realize the new method of cancer diagnostics. As the result of the work, a quick (short consumption time for diagnostic treatment), in-vivo (directly applicable to human skim) system has been successfully completed. The system uses fluorescent species caused by the enzyme reaction to detect the object enzyme activities by means of optical technique using a pair of optical fibers; one is for delivering excitation light source and the other for guiding signal light to a highly sensitive photo-detector. The higher activity of the enzymes reveals the steeper slope in the curve of luminescent power increase and thus it can be evaluate from the behavior of the fluorescent power at the fiber sensor output.Because of its smallness in diameter and flexibility, a plastic optical fiber was employed as the fiber sensor and thus it allows us to access to anywhere in a body. We found, however, that optimum condition in the space between sensor head and the object to be tested exists at Immseparation.In conclusions, non-contact operation of the new cancer diagnostic method is now technically possible and we have a plan to continue the research for practical use of the fiber optic sensor system to real medial cancer diagnostics.