Department of Mechanical Engineering, The University of British Columbia, Vancouver, BC, Canada.
Biomed Microdevices. 2011 Aug;13(4):641-9. doi: 10.1007/s10544-011-9534-6.
A fiber optic confocal catheter with a micro scanning lens was developed for real-time and non-contact thickness measurement of biological tissue. The catheter has an outer diameter and rigid length of 4.75 mm and 30 mm respectively and is suitable for endoscopic applications. The catheter incorporates a lens actuator that is fabricated using microelectromechanical systems (MEMS) technology. The lens is mounted on a folded flexure made of nickel and is actuated by magnetic field. Thickness measurements are performed by positioning the catheter in front of the tissue and actuating the lens scanner in the out-of-plane direction. A single-mode optical fiber (SMF) is used to deliver a 785 nm laser beam to the tissue and relay back the reflected light from the tissue to a photomultiplier tube (PMT). When the focal point of the scanning lens passes tissue boundaries, intensity peaks are detected in the reflecting signal. Tissue thickness is calculated using its index of refraction and the lens displacement between intensity peaks. The utility of the confocal catheter was demonstrated by measuring the cornea and skin thicknesses of a mouse. Measurement uncertainty of 8.86 µm within 95% confidence interval has been achieved.
一种带有微扫描透镜的光纤共焦导管被开发用于实时、非接触式生物组织厚度测量。该导管的外径和刚性长度分别为 4.75 毫米和 30 毫米，适用于内窥镜应用。导管采用微机电系统 (MEMS) 技术制造的透镜致动器。透镜安装在由镍制成的折叠柔性件上，并通过磁场驱动。通过将导管定位在组织前面并在离轴方向驱动透镜扫描仪来进行厚度测量。单模光纤 (SMF) 用于将 785nm 激光束传输到组织，并将组织反射的光中继到光电倍增管 (PMT)。当扫描透镜的焦点穿过组织边界时，在反射信号中检测到强度峰值。通过使用其折射率和强度峰值之间的透镜位移来计算组织厚度。通过测量小鼠的角膜和皮肤厚度来证明共焦导管的实用性。在 95%置信区间内，实现了 8.86 µm 的测量不确定度。
