Abstract：
Based on the well-known principle of selective photothermolysis, laser has been a promising way for the treatment of port wine stains (PWSs). The laser wavelengths used for PWS\'s clinical treatment include but are not limited to pulsed dye laser (PDL) in 585-600 nm, long-pulse 755-nm alexandrite, and 1064-nm Nd:YAG lasers. The objective of this study was to investigate the optimal wavelength for PWS\'s laser treatment. A two-scale mathematic model was constructed to simultaneously quantify macroscale laser energy attenuation in two-layered bulk skin and microscale local energy absorption on target blood vessels within Krogh unit. The effects of morphological parameters, including epidermal melanin content, epidermal thickness, dermal blood content, blood vessel depth, and diameter on laser energy deposition within target blood vessels, were investigated from the visible to near-infrared bands (500-1100 nm). The energy deposition ratio of target blood vessel to epidermal surface was proposed to determine the optimal laser wavelength for PWS with different skin morphological parameters. The bioheat transfer modeling and animal experiment are also conducted to prove our wavelength optimization. The optimal wavelengths for lightly pigmented skin with small and shallow target blood vessels are 580-610 nm in the visible band. This wavelength coincides with commercially used PDL. The optimal wavelength shifts to 940 nm as the epidermal pigmentation increases or the size and blood vessel depth increases. The optimal wavelength changes to 1005 nm as the epidermal pigmentation or the size and burying depth of target blood vessel further increases. Nine hundred forty nanometers can be selected as a general wavelength in PWS treatment to meet the need in most widely morphological structure. Lasers with wavelengths in the 580-610, 940, and 1005 nm regions are effective for treating PWS because of their high optical selectivity in blood over the epidermis.
摘要：
基于众所周知的选择性光热解原理，激光一直是治疗葡萄酒色斑（PWS）的一种有前途的方法。用于PWS临床治疗的激光波长包括但不限于585-600nm的脉冲染料激光（PDL），长脉冲755-nm翠绿宝石，和1064-nmNd:YAG激光器。本研究的目的是探讨PWS激光治疗的最佳波长。构建了双尺度数学模型，以同时量化两层块状皮肤中的宏观激光能量衰减和Krogh单元内目标血管上的微观局部能量吸收。形态参数的影响，包括表皮黑色素含量，表皮厚度,皮肤血液含量，血管深度,和目标血管内激光能量沉积的直径，从可见光到近红外波段（500-1100nm）进行了研究。提出了目标血管与表皮表面的能量沉积比，以确定具有不同皮肤形态参数的PWS的最佳激光波长。还进行了生物传热建模和动物实验以证明我们的波长优化。具有小而浅的目标血管的轻度色素皮肤的最佳波长在可见波段中为580-610nm。该波长与商业使用的PDL一致。随着表皮色素沉着的增加或大小和血管深度的增加，最佳波长移至940nm。随着表皮色素沉着或目标血管的大小和掩埋深度进一步增加，最佳波长变为1005nm。在PWS处理中可以选择九百四十纳米作为一般波长,以满足最广泛的形态结构的需要。波长在580-610、940和1005nm区域的激光器对于治疗PWS是有效的,因为它们在表皮上的血液中具有高的光学选择性。
