Ramachandran T, Sreenivasan K, Sivakumar R
Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, India.
Lasers Surg Med. 1996;19(4):413-5. doi: 10.1002/(SICI)1096-9101(1996)19:4<413::AID-LSM5>3.0.CO;2-V.
The heat balance equation is central to modeling laser vaporization of tissue. Because about 70% of tissue is water, energy loss due to water vaporization becomes an important consideration in modeling. In this study, the rate and pattern of water vaporization from various animal tissues studied by differential scanning calorimetry (DSC) are reported.
STUDY DESIGN/MATERIALS AND METHODS: DSC thermograms of fresh muscle, liver, and kidney tissues were made at heating rates of 2 degrees C/min, 5 degrees C/min, and 10 degrees C/min in the temperature range of 30-150 degrees C. Thermograms of vacuum-dried muscle sample were also made to establish that the endotherms obtained were essentially due to the water in the tissue.
Two broad peaks-one below and the other above 100 degrees C-are seen in all the endotherms. The peaks are attributed to the structural and compositional features of tissue and tissue water. The two-stage vaporization pattern has importance in modeling tissue heating by a continuous-wave Nd:YAG laser.
热平衡方程是组织激光汽化建模的核心。由于约70%的组织是水，因此在建模时，因水汽化导致的能量损失成为一个重要的考虑因素。在本研究中，报告了通过差示扫描量热法（DSC）研究的各种动物组织水汽化的速率和模式。
研究设计/材料与方法：在30 - 150℃温度范围内，以2℃/分钟、5℃/分钟和10℃/分钟的加热速率对新鲜肌肉、肝脏和肾脏组织进行DSC热分析。还对真空干燥的肌肉样本进行了热分析，以确定所获得的吸热峰主要是由于组织中的水所致。
在所有吸热曲线中均可见两个宽峰——一个低于100℃，另一个高于100℃。这些峰归因于组织和组织水的结构及组成特征。这种两阶段汽化模式在连续波Nd:YAG激光加热组织的建模中具有重要意义。
