The idea that led to a major advancement in laser surgery originated with Dr. J. Stuart Nelson at UC Irvine in 1992 while he was watching a baseball game. At the time, Nelson and his colleagues at the Beckman Laser Institute & Medical Clinic (BLIMC) were seeking ways to improve laser treatments for vascular birthmarks, such as port-wine stains, particularly in infants and young children.
The BLIMC was unique for combining research laboratories and an outpatient clinic under one roof, which allowed researchers to quickly apply new scientific findings to patient care. Nelson served as medical director during this period.
Laser treatment for birthmarks had significant limitations because the intense light could damage the skin’s surface, leading to pain and scarring. The challenge was finding a method that would protect the outer layer of skin while still targeting deeper blood vessels.
Nelson worked with postdoctoral researcher Thomas Milner and visiting engineer Lars Svaasand on different cooling techniques before laser exposure, including ice cubes and chilled metal plates. These methods proved impractical and also cooled the targeted blood vessels, reducing effectiveness.
“We needed to get something very cold onto the skin surface in perfect thermal contact and then off the skin surface – all within a fraction of a second,” Nelson said. “I remembered what I saw watching a baseball game.”
He recalled seeing trainers use ethyl chloride spray on injured players during games. Over dinner with his colleagues, they discussed adapting spray cooling for lasers if it evaporated quickly enough to only affect the top layer of skin.
Milner and Svaasand built a prototype using automotive parts over that weekend. They tested their Dynamic Cooling Device (DCD) on themselves before moving forward. “It was a fairly simple construction,” Milner said. “That’s the beauty of the invention: It’s so simple and works so well.”
The DCD sprays a nonflammable coolant onto the skin at -60 degrees Celsius just before each pulse of laser light. This rapid cooling protects only the uppermost layer of skin without affecting deeper tissues, allowing higher doses of laser energy while minimizing pain or injury.
“Because the spurt durations are so short, the cooling remains confined to the skin’s most superficial layer and does not affect the deeper targeted blood vessels causing the vascular birthmark,” Nelson explained. “This allows much higher laser light dosages to be used, while at the same time minimizing injury to the skin and pain to the patient.”
Patented in 1998 and licensed commercially by Candela Laser Corp., DCD technology became standard on more than 47,000 Candela lasers worldwide before its patent expired in 2020. The device also appears on lasers made by other companies globally.
Between 2001 and 2010, this invention ranked among University of California system’s top ten royalty earners from licensed inventions; it held second place in 2005 and third place in 2006.
Michael Berns, Arnold & Mabel Beckman Chair in Laser Biomedicine and institute co-founder, commented: “The combination of basic research, engineering and clinical testing that went into the Dynamic Cooling Device is exactly what was envisioned over 30 years ago when the idea of BLIMC was first conceived.”
Lasers equipped with DCD are now used for various cosmetic procedures but remain especially important for treating port-wine stains—a focus that continues at BLIMC’s Vascular Birthmarks & Malformations Diagnostic & Treatment Center where Nelson has treated more than 20,000 cases.
“The technology has made possible early, painless, safe and effective treatment of port-wine stains and other disfiguring vascular birthmarks in infants and young children in ways that Tom, Lars and I could never have imagined,” Nelson said. “That’s what I’m most proud of.”
