EXCITATION WAVELENGTH DEPENDENT RAMAN SPECTROSCOPY OF ARTERY

我们已经形成了惯性约束机构的理论 生物组织的消融。这一理论背后的动机是 组织中吸收的能量密度(E)的观察 消融阈值处的亚表面(对于短脉冲)通常为10 比蒸发所需的时间小的倍数，和E数量级 ~200-300焦耳/厘米~3。因此，仅靠汽化不足以解释 脉冲消融和其他物理机制必须负责 在这么短的时间内切除组织。通过研究蒸汽表 (水被用作软组织的热力学模型)，有人发现 在以下条件下，能量密度增加300J/cm3 恒定体积，足以产生900巴的压力 纸巾。假定体积恒定是因为，对于 短脉冲(小于几百纳秒)，组织 惯性受限(它缺乏足够的时间进行扩张)。烧蚀 当激光r感应压力超过阈值时发生 (这取决于组织的结构属性)和 在微裂缝处进行组织解体， 随后由于压力而加速离开陨石坑 渐变。

We have formulated the theory of inertially confined mechanism for ablation of biological tissues. The motivation behind this theory is the observation that the energy density (E) absorbed in the tissue subsurface at ablation threshold (for short pulses) is typically ten times smaller than that required for vaporization, and of the order E ~ 200-300 J/cm3. Thus vaporization alone is inadequate to explain pulsed ablation, and other physical mechanisms must be responsible for tissue removal on this short time scale. By studying the steam tables (water is used as a thermodynamic model for soft tissue), one finds that an increase in energy density of 300 J/cm3, under conditions of constant volume, is sufficient to generate a pressure of 900 bars in the tissue. The condition of constant volume is assumed because, for short pulses (less than several hundred nanoseconds), the tissue is inertially confined (it lacks sufficient time to expand). Ablation occurs when the lase r-induced pressure exceeds a threshold value (which is dependent on the structural properties of the tissue) and proceeds through a disassembly of the tissue at the microcracks and subsequent acceleration away from the crater due to the pressure gradient.