Many experimental studies focus on the physical damage mechanisms of short-term exposure to laser radiation. In the nanosecond (ns) pulse range, damage in the Retinal Pigment Epithelium (RPE) will most likely occur at threshold levels due to bubble formation at the surface of the absorbing melanosome. The energy uptake of the melanosomes is one key aspect in modeling the bubble formation and damage thresholds. This work presents a thermal finite volume model for the investigation of rising temperatures and the temperature distribution of irradiated melanosomes. The model takes the different geometries and thermal properties of melanosomes into account, such as the heat capacity and thermal conductivity of the heterogeneous absorbing melanosomes and the surrounding tissue. This is the first time the size and shape variations on the melanosomes‘ thermal behavior are considered. The calculations illustrate the effect of the geometry on the maximum surface temperature of the irradiated melanosome and the impact on the bubble formation threshold. A comparison between the calculated bubble formation thresholds and the RPE cell damage thresholds within a pulse range of 3 to 5000 ns leads to a mean deviation of $\mu =\text{22}\text{mJ/cm2}$ with a standard deviation of $\sigma =\text{21}\text{mJ/cm2}$. The best results are achieved between the simulation and RPE cell damage thresholds for pulse durations close to the thermal confinement time of individual melanosomes.

许多实验研究集中于短期暴露于激光辐射的物理损伤机制。在纳秒（ns）脉冲范围内，视网膜色素上皮（RPE）的损坏很可能会在阈值水平上发生，这是由于吸收性黑素体表面形成了气泡。黑色素体的能量吸收是对气泡形成和损伤阈值建模的关键方面。这项工作提出了一个热有限体积模型，用于研究温度升高和辐照黑素体的温度分布。该模型考虑了黑素体的不同几何形状和热特性，例如非均质吸收黑素体和周围组织的热容和热导率。这是第一次考虑黑素体热行为的尺寸和形状变化。这些计算说明了几何形状对辐照的黑素体的最高表面温度的影响以及对气泡形成阈值的影响。在3到5000 ns的脉冲范围内，计算出的气泡形成阈值与RPE细胞损伤阈值之间的比较会导致平均偏差为$\mu =\text{22}\text{mJ /平方厘米}$ 标准偏差为 $\sigma =\text{21}\text{mJ /平方厘米}$。在接近单个黑素体热约束时间的脉冲持续时间下，在仿真和RPE细胞损伤阈值之间可获得最佳结果。