Reseach On Confocal Laser Scanning Fluorescence Edomicroscope

With its high-resolution real-time histological diagnosis and a certain depth tomography, confocal laser scanning endomicroscopy has become a research focus. By confocal laser scann-ing endomicroscopy, doctors can not only observe the surface of human internal organs' organizational form, but also diagnose epidermal cells in depth lesions without sampling, and fluorescent contrast agents can also be used in confocal laser scanning endomicroscopy, because it is specific and easy to operate. At present, there are a few commercial products on sale, but most products use fiber bundles program, and few domestic products, so the research on confocal laser scanning endomicroscopy is significance.A confocal laser scanning endomicroscopy has been developed, which employs a telecentric endomicroscopic optical system to achieve long-distance relay transmission of images, telecentric f-theta optical scanning and endomicroscopic imaging functions. Two-dimensional confocal scanning is realized through two scanning mirrors, Z-axis scanning is achieved by a piezoelectric motor, and low-noise control signals are generated by the embedded system. With combining these above, it achieve the three dimensional confocal scanning. Minia-turized design has been adopted in the confocal laser scanning endomicroscopy. Main contents include the following three aspects:(1) the design of endoscopic imaging optical system is completed, which meet a large field, a large numerical aperture and a long-distance relay trans-mission of image.The laser is coupled into the tissue in human body, and the fluorescence signal is coupled to detector out of body. It acquires high resolution and high contrast fluoresce-nce images,at the same time, reduces the endoscopic probe diameter. The outer diameter of the optical system is 8 mm, and working length of which is 250.3 mm, so in-vivo endomicroscopic imaging can be realized through standard laparoscopic surgery port. (2) two small mirrors with aperture of 3mm are employed to achieve in vitro confocal scanning, with the maximum frequency of 100Hz and maximum scan range of 600μm.They are controlled by embedded system to accomplish X, Y dimensional confocal scanning. (3) samples contains fluorescent reagent, and after laser excitation, PMT detect the florescence. The optical signal is converted into electrical signals, and can be uploaded to a PC for image reconstruction and processing. Laser system and fluorescence detection are connected with the distal end of the confocal laser scanning endomicroscopy through an optical fiber and a cable, the size and the weight of the distal end are minimized by this method. The experimental results show that the system's filed of view reachesφ600μm, its optical resolution is 2.2μm and its image resolution is 512x 320, getting a picture every 4 seconds. The system can be further developed into three-dimensional confocal imaging system, and can be used under handheld operation or other ways to realize minimally invasive in-vivo fluorescence endoscopic surgery since its miniature size and low weight.