Department of Physics, The University of Auckland, 23 Symonds Street, Auckland, New Zealand.
School of Chemical Sciences, The University of Auckland, 23 Symonds Street, Auckland, New Zealand.
Lasers Med Sci. 2020 Aug;35(6):1263-1270. doi: 10.1007/s10103-019-02899-x. Epub 2019 Nov 15.
Laser micromachining with ultrashort pulses has shown great promise for clean, safe surgical treatment of bone tissue. However, comparisons of performance and development of "best practice" have been hampered by the difficulty of comparing results across a wide variety of experimental approaches and under surgically irrelevant conditions (e.g., dried, dead bone). Using a femtosecond (fs) pulsed laser system (τ = 140 fs, repetition rate = 1 kHz, λ = 800 nm), a comprehensive study of femtosecond laser microsurgery using the standard metrics of laser micromachining (ablation threshold, incubation effects, ablation rates, effect of focal point depth within the material and heat affected zone (HAZ)) was conducted on live, freshly harvested bovine and ovine cortical bone. Three important points of optimism for future implementation in the surgical theatre were identified: (1) the removal of material is relatively insensitive to the focal point depth within the material, removing the need for extreme depth precision for excellent performance; (2) femtosecond laser ablation of fresh bone demonstrates very little incubation effect, such that multiple passes of the laser over the same region of bone removes the same amount of material; and (3) the complete absence of collateral damage, heat- or shock-induced, on both the macro- and microscopic scales can be achieved readily, within a broad parameter range. Taken together, these results indicate a handheld or robotic deployed fiber laser platform for femtosecond laser microsurgery is a very viable prospect.
飞秒脉冲激光微加工在清洁、安全的骨组织外科治疗方面显示出巨大的潜力。然而，由于在各种不同的实验方法和与手术无关的条件下（例如，干燥、死亡的骨）难以比较结果，因此限制了性能比较和“最佳实践”的发展。使用飞秒（fs）脉冲激光系统（τ = 140 fs，重复率 = 1 kHz，λ = 800 nm），对活的、新收获的牛和羊皮质骨进行了飞秒激光微手术的综合研究，使用激光微加工的标准指标（消融阈值、潜伏期效应、消融速率、材料内焦点深度的影响和热影响区（HAZ））。对于未来在手术室内的实施，有三个重要的乐观点：（1）材料的去除相对不敏感于材料内的焦点深度，因此不需要极高的深度精度就能获得优异的性能；（2）新鲜骨的飞秒激光烧蚀几乎没有潜伏期效应，因此激光在同一骨区域多次通过可去除相同量的材料；（3）在广泛的参数范围内，在宏观和微观尺度上都可以轻易地实现完全没有热或冲击诱导的副损伤。综上所述，这些结果表明，手持式或机器人部署的光纤激光平台用于飞秒激光微手术是一个非常可行的前景。
