为了增加硬质内窥镜的有效视场,便于手持操作,节约成本,需要对现有硬质内窥镜的性能进行改进。首先,分析国内外硬质内窥镜的发展现状以及存在的主要问题,对比相关产品提出设计要求;接着,提出一种30°视向角硬质内窥镜的设计方法;然后,在分析目前市场上各类硬质内窥镜转向系统结构的基础上,提出使用全反射棱镜设计30°视向角内窥镜的方法;最后,结合相应标准对设计结果进行公差分析与像质评价。设计结果表明:所设计内窥镜的总长度为365 mm;口径小于6 mm;视场角为±40°;物方分辨率为12 lp/mm,接近衍射极限;能量分布均匀。考虑加工和装调误差,进行公差分析后结果显示像质满足用户需求。设计结果基本能够满足实际使用需求,达到设计要求,对硬质高质量医用内窥镜的国产化具有工程应用意义。

In order to increase the valid view of field, make it easy for using, and save cost, it's necessary to improve the performance of the existing rigid endoscope. Firstly, the development status and main problems of rigid endoscopes at home and abroad are analyzed. And the design requirement is proposed by comparing related product. Next, a design method of 30° viewing angle rigid endoscope is proposed. Then, on the basis of the analysis of the current steering system structure of all kinds of rigid endoscope on the market, a method of designing the 30° viewing angle endoscope with total reflection prism is proposed. Finally, the tolerance analysis and image quality evaluation are carried out according to the corresponding standard. The design results show that the total length of the designed endoscope is 365 mm. The diameter is less than 6 mm. The angle of the field of view is ±40°. And the object space resolution is 12 lp/mm, which is close to the diffraction limit. The energy distribution is uniform as well. Considering the processing and assembly error, the results show that the image quality can still meet the user needs after the tolerance analysis. The design results can basically meet the actual use needs and the design requirements, which have engineering application significance for the localization of high quality medical rigid endoscope.