具有在线形貌矫正能力的组织体光学参数测量系统

针对具有复杂形貌的大面积组织体,基于空间频率域方法,提出并搭建了一种具有在线形貌矫正能力的绝对光学参数测量系统.首先利用相位轮廓术获取组织体三维表面轮廓,用余弦辐射公式法矫正由组织体表面复杂形貌引起的光照度的差异.然后,采用漫反射板代替传统方法中的参考仿体,基于空间频率域测量模式进行绝对光学参数测量,并利用提出的光学参数反演方法实现组织体吸收系数的重建.组织仿体实验结果表明,对于表面高度小于29mm的仿体,经矫正后,吸收系数的测量相对误差从60%下降到13%.

Optical Parameters Measurement System for Tissues withOn-line Surface Profile Correction

A measurement system for on-line determination of optical properties of tissue with large areas and correction of complex surface profile was developed.First,the three-dimensional surface profile of the tissues was obtained with phase profilometry.According to cosine radiator model,the change of illumination,which was caused by complex surface profile of the tissues,was corrected.Then,diffuse plane was used to replace the phantom in the traditional method,and the absolute optical parameters based on spatial frequency domain measure mode were measured.The absorption coefficient of the tissues was reconstructed using the developed method.Tissues phantoms with height variation less than 29 mm were adopted to verify the method,the relative error of absorption coefficient decreased from 60% to 13% compared to that without correction.