title: Radiometric surface temperature measurements during dye-assisted laser skin closure: in vitro and in vivo results.
abstract: OBJECTIVE
  A thermal camera was used to measure surface temperatures during laser skin welding to provide feedback for optimization of the laser parameters.
  
  
  METHODS
  Two-centimeter-long, full-thickness incisions were made in guinea pig skin in vitro and in vivo. India ink was applied to the incision edges, which were then mechanically apposed. Continuous-wave, 1.06-microm Nd:YAG laser radiation was scanned over the incisions, producing an effective pulse duration of approximately 100 msec. Cooling durations between scans of 1.6, 4.0, and 8.0 sec were studied in vitro. A 5-mm-diameter laser spot was used with the power kept constant at 10 W. Thermal images were obtained at 30 frames per second with a thermal camera detecting 3-5 microm radiation. Surface temperatures were recorded at 0, 1, and 6 mm from the center line of the incision.
  
  
  CONCLUSIONS
  Cooling durations of 1.6 and 4.0 seconds in vitro resulted in temperatures at the weld site that remained above approximately 65 degrees C for prolonged periods of time. Cooling durations of 8.0 seconds were sufficient both in vitro and in vivo to prevent a significant rise in baseline temperatures at the weld site over time.
authors.affiliation: Biomedical Engineering Department, Northwestern University, Evanston, Illinois 60208, USA. nfried@bme.jhu.edu
authors.forename: N M
authors.initials: NM
authors.lastname: Fried
authors.forename: B
authors.initials: B
authors.lastname: Choi
authors.forename: A J
authors.initials: AJ
authors.lastname: Welch
authors.forename: J T
authors.initials: JT
authors.lastname: Walsh
mesh_terms: D000818:Animals; D001831:Body Temperature; D002244:Carbon; D004396:Coloring Agents / Q000737:chemistry; D046508:Culture Techniques; D062109:Dermatologic Surgical Procedures; D004195:Disease Models, Animal; D006168:Guinea Pigs; D006358:Hot Temperature; D007432:Intraoperative Period; D017075:Laser Coagulation / Q000295:instrumentation* / Q000379:methods; D016343:Monitoring, Intraoperative; D012680:Sensitivity and Specificity; D012867:Skin / Q000528:radiation effects; D013499:Surface Properties; D014741:Video Recording; D014945:Wound Healing / Q000502:physiology / Q000528:radiation effects
chemical_list: D004396:Coloring Agents; C028433:chinese ink; D002244:Carbon