Basic study to establish the method to evaluate surface vascular lesions by utilization of optical coherence tomography.

这项研究是在没有获得光学相干断层扫描(OCT)系统的情况下开始的。OCT系统的主要供应商被另一家公司收购。同时，OCT系统正在申请审批，这也阻碍了我们获得OCT系统。虽然研究的开始有了很大的延迟，但在大阪大学一个研究小组的帮助下，我们成功地取得了以下结果。我们的目标是利用OCT系统用一种非侵入性的方法评估表面动脉的动脉硬化性变化和糖尿病的变化。虽然OCT系统的标准空间分辨率可能为10-20微米，但最大扫描距离仅为1毫米，因此我们选择指背动脉作为测量对象，因为它们正好位于皮下，在OCT系统下易于定位。实验表明，即使是指动脉，其最大扫描距离也是不够的，而且动脉在视场中的定位非常困难，因此对指动脉的描述很差，无法对测量过程进行优化。为了提高扫描距离，我们正在开发一种新的OCT系统，该系统使用1.53微米波长激光和聚焦相干门检测光学系统，并借助高频超声探头来定位视场中的目标。为了最大限度地减少运动伪影的影响，我们在低频下测试了一种带有光纤PZT调制器的高速OCT系统。我们之前的研究主要集中在表面动脉测量硬件的开发上。我们现在正在进入一个新的研究阶段，开发将OCT系统应用于临床的软件。

This study was begun without means of obtaining the optic coherence tomography (OCT) system. The main supplier of OCT systems went under acquisition by another company. And at the same time, the OCT system was undergoing application for approval, which also prevented us from obtaining the OCT system. Though there was a major delay in the initiation of our research, we have managed to achieve the following results with the help from a research group in University of Osaka.We aimed to evaluate arteriosclerotic changes and diabetic changes of the surface arteries by a non-invasive method using OCT system. While the standard spatial resolution of OCT systems may be 10-20 micrometers, the maximum scanning distance is only one millimeter, so we selected the dorsal digital arteries as our measurement target since they are situated aright under the skin and easy to position under the OCT system. The experiment showed that the maximum scanning distance was insufficient even for the digital arteries and the localization of the arteries in the field of view was very difficult Consequently the depiction of the digital arteries was so poor that the optimization of the measurement process was not possible. To improve the scanning distance, we are now developing a new OCT system using 1.53-micrometer wave length laser and in-focus coherence gate detection optic system with the aid of a high-frequency ultrasound probe to localize the target in the field of view. And to minimize the effect of motion artifacts, we have tested a high-speed OCT system with an optic fiber PZT modulator in the low frequency inferometer.Our previous research have been mainly in the development of the hardware to measure surface arteries. We are now entering a new phase of our research to develop the software to apply the OCT system to clinical uses.