Laser and Optoelectronics Engineering Department, University of Technology, Baghdad, Iraq.
Lasers Med Sci. 2019 Oct;34(8):1671-1678. doi: 10.1007/s10103-019-02767-8. Epub 2019 Mar 15.
A new methodology has been proposed to measure optical properties of homogeneous tissue where a laser beam is used to induce heat to a tissue. The induced heat increased the temperature inside the tissue, which is detected by a thermocouple. These readings are compared with that obtained from the solution of the finite element solution that used iterative values of optical properties in determining temperature distribution. The two temperature distributions are used to determine tissue optical properties using the Levenberg-Marquardt iteration. An accurate result is obtained in determining absorption coefficient and reduced scattering coefficient. The work is extended to obtain three parameters (i.e., absorption coefficient, scattering coefficient, and anisotropy). The only limitation is that the temperature readings have to be measured with a high-accuracy thermocouple (i.e., less than 0.4% of maximum-recorded temperature).
提出了一种新的方法来测量同质组织的光学特性，其中使用激光束将热量诱导到组织中。所诱导的热量会增加组织内部的温度，这可以通过热电偶来检测。将这些读数与通过有限元解的迭代值来确定温度分布的解决方案获得的读数进行比较。使用 Levenberg-Marquardt 迭代法，通过这两个温度分布来确定组织的光学特性。在确定吸收系数和降低散射系数方面，可以获得准确的结果。该工作扩展到获得三个参数（即吸收系数、散射系数和各向异性）。唯一的限制是必须使用高精度热电偶来测量温度读数（即记录的最大温度的误差小于 0.4%）。
