基于可见-近红外光谱的组织热毁损实时监测研究

探讨了基于可见-近红外光谱的生物组织激光热毁损实时监测的可行性.采用5W、808 nm激光对新鲜离体猪肝进行了热毁损实验,在距离毁损中心4、8、12 mm处实时采集可见-近红外光谱(330～1100 nm),选取波长720 nm的散射光强(Rd720)作为评判因子.结果表明:加热初期Rd720随组织温度升高而快速增强,光谱测量点与毁损中心距离越小,Rd720上升越快;达到有效毁损后,若保持加热,则温度继续上升而Rd720趋于平稳;停止加热后,组织温度逐渐恢复到室温,而Rd720微降后基本保持不变且远高于初始值.由此可见,生物组织的可见-近红外散射光强可以作为激光热毁损实时监测的一项重要参数.

Real-time monitoring of tissue thermal damage based on visible and near-infrared spectroscopy

The feasibility of real-time monitoring on biological tissue laser thermal damage based on visible and near-infrared spectroscopy is investigated.Thermal damage experiment is carried out in fresh porcine livers with laser of 5 W,808 nm.Visible and near-infrared spectra (330 ～ 1100 nm) are acquired in real time at distances of 4,8,12 mm from the damage center,and the diffused light intensity at 720 nm (Rd720)is chosen as the evaluation factor.Results show that Rd720 increases quickly with the increasing of tissue temperature in the initial stage of heating.The smaller the distance between the spectral measurement point and damage center is,the faster Rd720 will increase.After reaching the effective damage,temperature continues to rise while Rd720 tends to be stable if keeping heating.After the heating is stopped,the tissue temperature gradually returns to room temperature,while Rd720 decreases slightly and remains almost a constant which is far higher than its initial value.It can be found that the visible and near-infrared scattering intensity of biological tissue can be used as an important parameter to real-time monitoring laser thermal damage.