基于图像频谱能量集中度的频域光学相干层析术数值色散补偿

Numerical Dispersion Compensation in Spectral Domain Optical Coherence Tomography Based on Concentration of Energy in Image Spectrum

分析阐述了频域光学相干层析术(SDOCT)系统参考臂和样品臂之间的色散不匹配对所获取的图像的频谱能量分布的影响。提出了一种基于图像频谱能量集中度的SDOCT系统数值色散补偿方法。当图像频谱低频区域内的能量百分比最小时,表明系统色散匹配。实验中选取平面反射镜作为样品,验证了用该方法来衡量系统色散匹配的效果与传统的利用半峰全宽(FWHM)法来评定色散补偿的结果一致。最后获取了人体手指的在体光学断层图像,并用该方法进行了色散不匹配补偿。实验结果显示该方法能够有效地对系统色散进行补偿,从而提高了图像的分辨率。

The effects of the dispersion mismatch between the reference arm and the sample arm of spectral domain optical coherence tomography（SDOCT） system on the spectral energy distribution in the spectrum of the image obtained with SDOCT are discussed. A method of numerical dispersion compensation in SDOCT is proposed, which is based on the concentration of energy in the image spectrum. It has been shown that when the percentage of energy in the low- frequency area of the spectrum is minimized, the dispersion mismatch is balanced. The plane mirror is taken as the sample in experiment to demonstrate the method, showing that the dispersion mismatch balance achieved with our method is in accordance with that by the full width at half maximum（FWHM） based method. Finally the optical cross-sectional image of a finger is obtained in vivo and the dispersion mismatch is balanced with the method. The results show that the method can effectively compensate the dispersion mismatch and improve the resolution of the images.