Pikkula B M, Torres J H, Tunnell J W, Anvari B
Department of Bioengineering, Rice University, Houston, Texas 77251, USA.
Lasers Surg Med. 2001;28(2):103-12. doi: 10.1002/lsm.1024.
Cryogen spray cooling (CSC) is an effective method to reduce or eliminate non-specific injury to the epidermis during laser treatment of various dermatological disorders. In previous CSC investigations, fuel injectors have been used to deliver the cryogen onto the skin surface. The objective of this study was to examine cryogen atomization and heat removal characteristics of various cryogen delivery devices.
STUDY DESIGN/MATERIALS AND METHODS: Various cryogen delivery device types including fuel injectors, atomizers, and a device currently used in clinical settings were investigated. Cryogen mass was measured at the delivery device output orifice. Cryogen droplet size profiling for various cryogen delivery devices was estimated by optically imaging the droplets in flight. Heat removal for various cryogen delivery devices was estimated over a range of spraying distances by temperature measurements in an skin phantom used in conjunction with an inverse heat conduction model.
A substantial range of mass outputs were measured for the cryogen delivery devices while heat removal varied by less than a factor of two. Droplet profiling demonstrated differences in droplet size and spray density.
Results of this study show that variation in heat removal by different cryogen delivery devices is modest despite the relatively large difference in cryogen mass output and droplet size. A non-linear relationship between heat removal by various devices and droplet size and spray density was observed.
冷冻喷雾冷却（CSC）是一种在激光治疗各种皮肤病时减少或消除对表皮非特异性损伤的有效方法。在以往的CSC研究中，一直使用燃料喷射器将冷冻剂输送到皮肤表面。本研究的目的是研究各种冷冻剂输送装置的冷冻剂雾化和散热特性。
研究设计/材料与方法：研究了包括燃料喷射器、雾化器以及目前临床使用的一种装置在内的各种冷冻剂输送装置类型。在输送装置的输出孔处测量冷冻剂质量。通过对飞行中的液滴进行光学成像，估算各种冷冻剂输送装置的冷冻剂液滴尺寸分布。结合逆热传导模型，通过在皮肤模型中进行温度测量，在一系列喷雾距离范围内估算各种冷冻剂输送装置的散热情况。
测量了冷冻剂输送装置的大量质量输出，而散热变化不到两倍。液滴分布显示了液滴尺寸和喷雾密度的差异。
本研究结果表明，尽管冷冻剂质量输出和液滴尺寸存在较大差异，但不同冷冻剂输送装置的散热变化不大。观察到各种装置的散热与液滴尺寸和喷雾密度之间存在非线性关系。
