采用空间分辨漫反射测定胃组织光学特性

研究了人正常胃黏膜及黏膜下层组织对488 nm,514.5 nm,532 nm,630 nm和632.8 nm的激光的光学特性及其差异,实验采用空间分辨反射光和CCD探测器以及非线性拟合确定组织光学特性。结果表明,人正常胃黏膜及黏膜下层组织对五个波长的激光的吸收系数、约化散射系数、光学穿透深度、漫射系数、漫反射率和漫反射率的位移都是随着激光波长的变化而变化的。其吸收系数的最大值在532 nm,其值为0.482 mm-1,最小值在632.8 nm,其值为0.224 mm-1,最大差异在532 nm和632.8 nm之间,其值为115%,最小差异在488 nm和532 nm之间,其值为1.90%。其约化散射系数的最大值在488 nm,其值为5.93 mm-1,最小值在632.8 nm,其值为3.87 mm-1,最大差异在488 nm和632.8 nm之间,其值为53.2%,最小差异在514.5 nm和532 nm之间,其值为3.25%。其光学穿透深度的最大值在632.8 nm,其值为0.612 mm,最小值在488 nm,其值为0.341 mm。其漫射系数的最大值在632.8 nm,其值为0.084 mm,最小值在488 nm,其值为0.055 mm。其漫反射率的最大值在630 nm,其值为0.356,最小值在532 nm,其值为0.271。其Δx的最大值在632.8 nm,其值为0.153 mm,最小值在488 nm,其值为0.100 mm。可见,人正常胃黏膜/黏膜下层组织对五个波长的激光的光学特性参数存在明显的差异。

Using Spatially Resolved Reflectance to Measure Optical Properties of Stomach Tissue

The optical properties and differences for normal human stomach mucosa/submucosa tissues in vitro at 488 nm,514.5 nm,532 nm,630 nm and 632.8 nm wavelengths of laser were determined in this paper.Measurements were performed using a charge coupled device(CCD) detector,and optical properties were assessed from the measurements using the spatially resolved reflectance,and nonlinear fitting of diffusion equation.The results of measurement showed that absorption coefficients,reduced scattering coefficients,optical penetration depths,diffusion constants,diffuse reflectance and shifts of the diffuse reflectance of the tissue samples at five different laser wavelengths vary with a change of laser wavelength.The maximum absorption coefficient for tissue samples is 0.482 mm-1 at 532 nm,and the minimum absorption coefficient is 0.224 mm-1 at 632.8 nm;the maximum difference in the absorption coefficients is 115% between 532 nm and 632.8 nm,and the minimum difference is 1.90% between 488 nm and 532 nm.The maximum reduced scattering coefficient for tissue samples is 5.93 mm-1 at 488 nm,and the minimum reduced scattering coefficient is 3.87 mm-1 at 632.8 nm;the maximum difference in the reduced scattering coefficients is 53.2% between 488 nm and 632.8 nm,and the minimum difference is 3.25% between 514.5 nm and 532 nm.The maximum optical penetration depth for tissue samples is 0.612 mm at 632.8 nm,and the minimum optical penetration depth is 0.341 mm at 488 nm.The maximum diffusion constant for tissue samples is 0.084 mm at 632.8 nm,and the minimum diffusion constant is 0.055 mm at 488 nm.The maximum diffuse reflectance for tissue samples is 0.356 at 630 nm,and the minimum diffuse reflectance is 0.271 at 532 nm.The maximum shift of the diffuse reflectance of the oblique incidence for tissue samples is 0.153 mm at 632.8 nm, and the minimum shift of the diffuse reflectance of the oblique incidence is 0.100 mm at 488 nm.It is obvious that there were distinct differences in the optical parameters for normal human stomach mucosa/submucosa tissues at five different laser wavelengths.