Kuzmin Vladimir L, Neidrauer Michael T, Diaz David, Zubkov Leonid A
St. Petersburg State University, Department of Physics, Ulyanovskaya ul. 3, St. Petersburg 198504, RussiabSt. Petersburg State University of Trade and Economics, Department of Statistics, Novorossiyskaya ul. 50, St. Petersburg 194021, Russia.
Drexel University, School of Biomedical Engineering, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
J Biomed Opt. 2015 Oct;20(10):105006. doi: 10.1117/1.JBO.20.10.105006.
Diffuse photon density wave (DPDW) methodology is widely used in a number of biomedical applications. Here, we present results of Monte Carlo simulations that employ an effective numerical procedure based upon a description of radiative transfer in terms of the Bethe–Salpeter equation. A multifrequency noncontact DPDW system was used to measure aqueous solutions of intralipid at a wide range of source–detector separation distances, at which the diffusion approximation of the radiative transfer equation is generally considered to be invalid. We find that the signal–noise ratio is larger for the considered algorithm in comparison with the conventional Monte Carlo approach. Experimental data are compared to the Monte Carlo simulations using several values of scattering anisotropy and to the diffusion approximation. Both the Monte Carlo simulations and diffusion approximation were in very good agreement with the experimental data for a wide range of source–detector separations. In addition, measurements with different wavelengths were performed to estimate the size and scattering anisotropy of scatterers.
扩散光子密度波（DPDW）方法在许多生物医学应用中被广泛使用。在此，我们展示了蒙特卡罗模拟的结果，该模拟采用了一种有效的数值程序，该程序基于以贝特 - 萨尔皮特方程描述辐射传输。使用多频非接触DPDW系统在广泛的源 - 探测器分离距离下测量脂质乳剂水溶液，在这些距离下，辐射传输方程的扩散近似通常被认为是无效的。我们发现，与传统的蒙特卡罗方法相比，所考虑的算法的信噪比更大。将实验数据与使用多个散射各向异性值的蒙特卡罗模拟以及扩散近似进行比较。对于广泛的源 - 探测器分离范围，蒙特卡罗模拟和扩散近似都与实验数据非常吻合。此外，进行了不同波长的测量以估计散射体的大小和散射各向异性。
