Thermal and Biological Responses of Tissue to Cryogen Spray Cooling and Pulsed Laser Irradiation

Dr. Wangcun Jia
Beckman Laser Institute and Medical Clinic
University of California, Irvine
Irvine, CA 92617

In  laser  dermatologic  surgery,  pulsed  laser  irradiation  in  conjunction  with cryogen spray cooling allows controlled heating of a specific target underneath human skin  such  as  malformed  blood  vessels,  hair  follicles  etc.  In  this  talk,  I  will  first  briefly introduce  the  fundamentals,  namely  selective  photothermolysis  and  dynamic  skin cooling.  I  will  then  present  my  research  on  the  following  topics:  1)  Environmentally- and  patient-friendly  cryogen  spray  cooling  technique  which  reduces  contribution  to global  warming  and  alleviates  patient  discomfort;  2)  Study  of  laser  therapy  to  treat  disfiguring port wine stain birthmarks using numerical and animal models. It was found that  severely  damaged  blood  vessels  can  be  regenerated  within  two  weeks,  which may explain why birthmark blanching cannot be achieved even significant vessel injury is  induced;  and  3)  Combined  laser  and  antiangiogenic  therapy  to  improve  the therapeutic  outcome  of  port  wine  stain  birthmarks.  The  rational  of  the  combined therapy is that laser is used to induce injury of the malformed blood vessels, and then an   antiangiogenic   drug   is   subsequently   administered   to   prevent   blood   vessel reformation and reperfusion. Encouraging clinical result has been recently achieved.

Dr. Jia received his Ph.D. degree in Mechanical Engineering from the Hong Kong University  of Science and  Technology  in  2001  with  an  emphasis  in  heat  transfer  and laser  diagnostics.  After  completing  his  postdoctoral  fellowship  in  the  Boiling  Heat Transfer Lab at UCLA, Dr. Jia joined the Beckman Laser Institute in 2004 where he is currently an Assistant Researcher. Dr. Jia’s research interests includes spray cooling, light tissue interaction, antiangiogenic therapy, laser dosimetry, infrared thermography and  laser  phase  Doppler  anemometry.  Dr.  Jia’s  most  recent  recognitions  include  Dr. Horace  Furumoto  Innovations  Professional  Development  Award  from  the  American Society for Laser Medicine and Surgery.