title: Experimental study of cryogen spray properties for application in dermatologic laser surgery.
abstract: Cryogenic sprays are used for cooling human skin during laser dermatologic surgery. In this paper, six straight-tube nozzles are characterized by photographs of cryogenic spray shapes, as well as measurements of average droplet diameter, velocity, and temperature. A single-droplet evaporation model to predict average spray droplet diameter and temperature is tested using the experimental data presented here. The results show two distinct spray patterns--sprays for 1.4-mm-diameter nozzles (wide nozzles) show significantly larger average droplet diameters and higher temperatures as a function of distance from the nozzle compared with those for 0.5-0.8-mm-diameter nozzles (narrow nozzles). These results complement and support previously reported studies, indicating that wide nozzles induce more efficient heat extraction than the narrow nozzles.
authors.affiliation: Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA. gaguilar@bli.uci.edu
authors.forename: Guillermo
authors.initials: G
authors.lastname: Aguilar
authors.forename: Boris
authors.initials: B
authors.lastname: Majaron
authors.forename: Emil
authors.initials: E
authors.lastname: Karapetian
authors.forename: Enrique J
authors.initials: EJ
authors.lastname: Lavernia
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Nelson
mesh_terms: D000287:Administration, Topical; D000335:Aerosol Propellants / Q000008:administration & dosage; D002056:Burns / Q000209:etiology / Q000517:prevention & control*; D017679:Cryotherapy / Q000295:instrumentation / Q000379:methods*; D062109:Dermatologic Surgical Procedures; D003880:Dermatology / Q000379:methods*; D016503:Drug Delivery Systems / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods; D004869:Equipment Safety; D006358:Hot Temperature / Q000009:adverse effects; D006845:Hydrocarbons, Fluorinated / Q000008:administration & dosage / Q000737:chemistry*; D053685:Laser Therapy / Q000009:adverse effects / Q000379:methods; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods; D010316:Particle Size; D012212:Rheology / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D012867:Skin / Q000293:injuries; D012881:Skin Temperature / Q000528:radiation effects; D013696:Temperature; D013817:Thermography / Q000379:methods; D004980:Ethane / Q000031:analogs & derivatives; D005466:Fluorocarbons
chemical_list: D000335:Aerosol Propellants; D006845:Hydrocarbons, Fluorinated; C063006:norflurane; D004980:Ethane; D005466:Fluorocarbons