基于互相关运算的扫频光学相干层析成像延时校正算法  

A Delay Correction Algorithm for Swept Source Optical Coherence Tomography Based on Cross Correlation Operation

作　　者：卢宇[1,2] 李中梁[1,2] 南楠[1] 步扬[1,2] 陈艳[1,2] 王瑄[1,2] 王向朝[1,2] 

机构地区：[1]中国科学院上海光学精密机械研究所信息光学与光电技术实验室,上海201800 [2]中国科学院大学,北京100049

出　　处：《中国激光》2017年第6期260-267,共8页Chinese Journal of Lasers

基　　金：上海市科学技术委员会创新行动计划项目(15441905600);广西高校光电信息处理重点实验室开放基金资助项目(KFJJ2016-04)

摘　　要：提出了一种扫频光学相干层析成像k-clock延时校正算法,该算法基于互相关运算,能够有效校正光源自带k-clock信号的延时。由于扫频光源的不稳定性、同步触发硬件的精度不足以及外界环境影响,扫频光源自带的kclock信号在重采样干涉信号时很可能与干涉信号之间有一个不确定的延时,导致系统分辨率下降。通过实验获得一个标准k-clock信号,然后利用互相关运算计算出需要校正的k-clock信号的延时。由计算出的延时,将kclock信号进行左右移动从而对其进行校正,再利用三次样条插值获得波数域等间隔的干涉信号。实验结果表明,该算法平均运行时间为0.18s,能够将系统分辨率提高18.2%,改善系统性能。A new algorithm of k-clock delay correction for swept source optical coherence tomography is proposed. The algorithm is based on cross correlation operation and can effectively correct the delay of the swept source k- clock signal. Due to the instability of the swept source and the external environment, as well as lack of precision of the synchronous trigger hardware, the k-clock signal of the swept source may have an uncertain delay with the interference signal when resampling the interference signal, resulting in decreased system resolution. A standard k- clock signal is acquired by experiments, and then the delay of the k-clock signal is calculated using the cross correlation operation. According to the calculated delay, the k-clock signal is shifted left or right to correct the difference with the standard k-clock, and then the corrected k-clock signal is used to resample the interference signal at evenly wavenumber domain interval. The experimental results show that the system performance is improved. The average running time of the algorithm is 0.18 s, and the resolution of the system is improved by 18.2%.

关 键 词：医用光学 相干光学 扫频光学相干层析成像 互相关运算 延时校正 分辨率 

分 类 号：TH744[机械工程—光学工程]