高速稳定内窥光学相干层析成像系统

High-speed and stable endoscopic optical coherence tomography system

为了实现消化道高速在体病理诊断,提出了一种高速并稳定成像的内窥扫频光学相干层析成像系统设计。为了实现高速内窥成像,采用200 kHz扫频光源研制了高速内窥扫频光学相干层析成像系统,并利用现场可编程门阵列和图形处理单元相结合的硬件加速处理技术实现了数据的实时处理;为了提高成像稳定性,利用码盘反馈的脉冲信号进行系统逻辑控制,有效校正了图像漂移;对系统的成像速度和图像稳定性进行了测试分析,并进行了小鼠结直肠成像实验。实验结果表明:当图像尺寸为1024×1333时,系统实时成像速度可达141 frame/s;在逻辑控制时序下,系统图像稳定性从87.0%提高到98.6%以上;小鼠结直肠光学相干层析成像结果与病理切片结果一致。本文研制的系统具有高速稳定成像的特点,可在体、实时、清晰地区分小鼠结直肠组织的层析结构,有望为消化道等体腔疾病在体实时病理诊断提供一种全新的诊断方法。

In order to achieve high-speed in vivo pathological diagnosis of the digestive tract,a design method for an endoscopic optical coherence tomography system with high-speed and stable imaging was proposed.Firstly,in order to realize high-speed endoscopic imaging,a high-speed endoscopic optical coherence tomography system was developed by using a 200 kHz swept source,and the hardware accelerated processing technology,combining field programmable gate array and graphics processing unit was used to realize real-time data processing.Secondly,in order to improve the stability of imaging,the pulse signal fed back by the encoder was used for system logic control,which effectively corrects the image drift.Finally,the stability and imaging speed of the system were tested and analyzed,and the colorectal imaging experiment was carried out in a mouse.The experimental results show that the real-time imaging speed of the system can reach 141 frame/s when the image size is 1024×1333 pixels,and under the logic control timing,the system image stability is improved from 87.0% to over 98.6%.The optical coherence tomography imaging results from the mouse colorectum are consistent with those of the pathological sections.The system developed in this paper is characterized by high-speed and stable imaging,which can clearly distinguish the tomographic structure of the mouse colorectal tissue in vivo and in real time.It is expected to provide a new diagnostic method for the real-time pathological diagnosis of body cavity diseases.