【作者】 王强；

【导师】 袁波； 王立强；

【作者基本信息】 浙江大学 ， 信息传感及仪器， 2020， 硕士

【摘要】 医用电子内窥镜是一种可以直接进入人体的医疗器械,在医学诊断上发挥着重要作用。传统电子内窥镜的尺寸相对较大,在进入人体时需要对病人麻醉,会给病人带来伤害。而人体器官腔道尺寸变化范围大,一些小的腔道只有超细内窥镜(镜头尺寸一般小于5 mm)才能进入。本文设计并开发一套超细径的电子内窥镜系统,采用 1/18英寸的超小型CMOS图像传感器实现体内成像,使用USB2.0协议采集与传输图像数据,通过基于COMe架构并搭载WES系统的高性能嵌入式图像处理器来处理与显示图像。同时也设计了一套基于ARM A5处理器的便携式内窥镜系统,来满足不同场景下的需求。在内窥镜硬件系统中,本文首先介绍了图像传感模块,提出了数字图像的转换方法与该模块的电路架构。然后论述了图像数据采集模块的设计方案,基于USB2.0控制器设计了图像数据的采集与传输电路。最后设计了基于COMe架构的嵌入式图像处理器载板,将载板的尺寸控制在了 170 mm×170 mm。在超细径内窥镜的固件系统中,分别从图像传感器的初始化、图像数据的同步与USB控制器的固件编写三个方面做了论述。其中图像数据的同步采用了 Slave FIFO和GPIF两种方式,在USB控制器的固件中重点介绍了端点的配置,同步与发送程序的设计。最后还介绍了在WES系统下相关驱动的运用与应用软件的开发思路。针对便携式应用,本文还基于ARM A5处理器设计了一套手持式内窥镜系统。本部分中首先介绍了嵌入式Cortex-A5处理器SAMA5D31及其相关特性,然后讲述了如何利用ISI接口来接入图像传感器。紧接着论述了在Linux系统下图像传感器驱动的编写,最后介绍了基于V4L2框架下图像数据的采集流程。本论文对设计的超细径内窥镜系统作了功能验证与性能测试,结果表明系统能准确捕获图像,图像分辨率为400×400,且图像的帧率达到了 30帧。系统拥有较好的空间频率响应,亮度响应的线性拟合度高于90%,信噪比高于27dB,同时静态图像宽容度也能达到1 10以上。更多还原

【Abstract】 Medical electronic endoscope is a medical device that can enter the human body directly,which plays an important role in medical diagnosis.The size of the traditional electronic endoscope is relatively large,and the patients need to be anesthetized when entering their bodies,which will cause harm to them.The size of human organs has a large range of changes,and some small cavities can only be accessed by ultraslim endoscopes(The size of lens is generally smaller than 5 mm).A set of ultraslim electronic endoscope system based on 1/18 inch ultra-small CMOS image sensor is proposed in this paper.It uses USB2.0 protocol to collect and transmit data,processes and displays the image by a high-performance embedded image processor equipped with WES.At the same time,an endoscope system based on the arm processor is also designed to meet the needs in different scenarios.In the hardware system of the endoscope,the image sensing module is introduced in this paper at first.The module includes a digital image conversion method and the circuit architecture.Then the design scheme of image data acquisition module is discussed,and the image data acquisition and transmission circuit is designed based on USB2.0 controller.Finally,an embedded image processor carrier board based on COMe architecture is designed,and the size of the carrier board is controlled at 170 mm × 170 mm.In the firmware system of ultraslim endoscope,three aspects are discussed from the initialization of the image sensor,the synchronization of the image data,and the firmware writing of the USB controller.The synchronization of image data adopts Slave FIFO and GPIF.The firmware of USB controller focuses on the configuration of endpoint,and the design of synchronization and transmssion program.In addition,the use of related drivers in the WES system and the development of application software are introduced.For portable applications,a set of handheld endoscope system based on ARM A5 processor is designed in this paper too.Firstly,this section introduces the embedded Cortex-A5 processor SAMA5D31 and its related features.Then describes how to use ISI interface to access the image sensor.At last,the writing of image sensor driver under Linux system and the collection process of image data based on V4L2 framework is discussed.Functional verification and performance testing of the designed ultrathin diameter endoscope system were performed in this paper.The results showed that the system could accurately capture images with a resolution of 400 × 400 and displayed the images with 30 frames.The system had a good spatial frequency response,and the linearity of the brightness response was higher than 90%.Besides,the signal-to-noise ratio was higher than 27 dB,and the tolerance of the static image could also reach more than 110.更多还原