Marijnissen J P, Star W M
Department of Clinical Physics, Daniel den Hoed Cancer Centre, Erasmus University, Rotterdam, The Netherlands.
Phys Med Biol. 1996 Jul;41(7):1191-208. doi: 10.1088/0031-9155/41/7/008.
Miniature light detectors with isotropic response (isotropic light probes) permit quantitative measurement of light energy fluence rates in turbid media such as biological tissues. These isotropic probes are, for example, applied in photodynamic therapy to correlate light fluence in tissue with (tumour) tissue response, in vitro and in vivo. After description of its construction, two methods of calibration of an isotropic probe in air are discussed, in collimated and in diffuse light. The probe was first calibrated in air in collimated light, after which its response to diffuse light was checked in a flat and in a spherical geometry. Subsequently, the probe's response to collimated light in clear media, for example, water or glycerine which have refractive indices larger than that of air, has been established experimentally. The diffusion approximation to the transport equation in a simple spherical geometry has been used to calculate the probe's response as a function of the refractive index of clear media. The extent of agreement between theory and experiment indicates that the physical mechanisms are understood and indirectly validates the theoretical models.
具有各向同性响应的微型光探测器（各向同性光探头）能够对诸如生物组织等浑浊介质中的光能注量率进行定量测量。例如，这些各向同性探头被应用于光动力疗法中，以在体外和体内将组织中的光注量与（肿瘤）组织反应相关联。在描述了其构造之后，讨论了在空气中对各向同性探头进行校准的两种方法，即准直光校准和漫射光校准。该探头首先在空气中进行准直光校准，之后在平面和球形几何结构中检查其对漫射光的响应。随后，通过实验确定了该探头在诸如水或甘油等具有比空气大的折射率的透明介质中对准直光的响应。在简单的球形几何结构中，利用输运方程的扩散近似来计算探头响应作为透明介质折射率的函数。理论与实验之间的吻合程度表明物理机制已被理解，并间接验证了理论模型。
