Femtosecond laser surgery in the ablation cooling regime for improved depth and speed

该项目将研究超快激光在“烧蚀-冷却”状态下工作的物理效应，其中短激光脉冲以非常高的脉冲重复频率工作，以便脉冲在热量在组织中消散之前发生。这可以克服在正常低重复率下激光切割组织所造成的困难。其优点包括提高切割效率，提高产品材料的去除率，使用较低的功率，并允许更深的穿透深度。这将对手术精度微调、深层组织穿透和产品移除至关重要的系统的操作产生显著影响，例如声带病变或脊柱手术。该项目采用了一种突发模式飞秒激光系统，该系统将以近1.5 GHz的速率提供脉冲，从而将高能量沉积到目标区域。研究人员假设，这种突发模式GHz脉冲串将导致更深的亚表面消融。PI进一步预测，与传统kHz重复率飞秒激光器相比，这种脉冲序列将导致消融率的数量级增加，此外还避免了热副作用。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will study the physical effects of ultra-fast lasers operating in the 'ablation-cool' regime, where the short laser pulses operate at a very high pulse rep-rate so that the pulses occur before the heat is dissipated in the tissue. This can overcome the difficulties that result from laser-cutting tissue at the normal low rep-rates. The advantages include enhanced efficiency of cutting, improved removal-rates of products material, use of lower powers, and allowing deeper penetration depths. This will have a pronounced impact on the operation in systems where fine-tuning of accuracy of surgery, deep tissue penetration, and product removal are critical, such as vocal cords lesions or spine surgeries.The project utilizes a burst-mode femtosecond laser system that would deliver pulses at nearly 1.5 GHz rate leading to high energy deposited into the target area. The investigators hypothesize that such a burst mode GHz train of pulses would result in a deeper sub-surface ablation. The PIs further predict that such a pulse train will lead to an order-of-magnitude increase in ablation rates compared to conventional kHz repetition rate femtosecond lasers, in addition to avoiding thermal side effects.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.