Guo Shoujing, Wei Shuwen, Lee Soohyun, Sheu Mary, Kang Sewon, Kang Jin U
1Electrical and Computer Engineering DepartmentJohns Hopkins UniversityBaltimoreMD21218USA.
2Department of DermatologyJohns Hopkins Medicine - Green Spring StationLuthervilleMD21093USA.
IEEE J Transl Eng Health Med. 2019 Sep 25;7:1800608. doi: 10.1109/JTEHM.2019.2943317. eCollection 2019.
Tissue temperature monitoring during cutaneous laser therapy can lead to safer and more effective treatments. In this study, we investigate the use of speckle variance optical coherence tomography (svOCT) to monitor real-time temperature changes in the excised human skin tissue sample during laser irradiation. To accomplish this, we combined the pulse laser system with a reference-based svOCT system. To calibrate the svOCT, the ex-vivo human skin samples from three individuals with tissues collected from the arm, face, and back were heated with 1-degree increments. Additionally, linear regression was used to extract and evaluate the linear relationship between the temperature and normalized speckle variance value. Experiments were conducted on excised human skin sample to monitor the temperature change during laser therapy with a svOCT system. Thermal modeling of ex-vivo human skin was used to numerically simulate the laser-tissue interaction and estimate the thermal diffusion and peak temperature of the tissue during the laser treatment. These results showed that normalized speckle variance had a linear relationship with the tissue temperature before the onset of tissue coagulation (52°) and we were able to measure the rapid increase of the tissue temperature during laser therapy. The result of the experiment is also in good agreement with the numerical simulation result that estimated the laser-induced peak temperature and thermal relaxation time.
皮肤激光治疗期间的组织温度监测可带来更安全、更有效的治疗效果。在本研究中，我们探究了利用散斑方差光学相干断层扫描（svOCT）监测激光照射期间离体人类皮肤组织样本中的实时温度变化。为实现这一目的，我们将脉冲激光系统与基于参考的svOCT系统相结合。为校准svOCT，取自三名个体手臂、面部和背部组织的离体人类皮肤样本以1度的增量进行加热。此外，采用线性回归来提取和评估温度与归一化散斑方差值之间的线性关系。利用svOCT系统对离体人类皮肤样本进行实验，以监测激光治疗期间的温度变化。采用离体人类皮肤的热模型对激光与组织的相互作用进行数值模拟，并估计激光治疗期间组织的热扩散和峰值温度。这些结果表明，在组织凝固（52°）开始之前，归一化散斑方差与组织温度呈线性关系，并且我们能够测量激光治疗期间组织温度的快速升高。实验结果也与估计激光诱导峰值温度和热弛豫时间的数值模拟结果高度吻合。
