Steve Zylius / UC Irvine
J. Stuart Nelson demonstrates the dynamic cooling device in 2011.
The idea that revolutionized laser surgery came to Dr. J. Stuart Nelson in 1992, while watching a baseball game.
In the early 1990s, surgeons such as J. Stuart Nelson sought to adapt laser technology for medical use, and the Beckman Laser Institute & Medical Clinic (BLIMC) was the epicenter of this effort.
At the time, it was only installation in the world to bring together, under the same roof, research laboratories basic science and engineering and an outpatient clinic, allowing researchers and surgeons to quickly turn laboratory discoveries into advances in patient care.
As clinical director of BLIMC, Nelson was committed to improving laser treatments for birthmarks disfiguring vascular lesions, such as port-wine stains, in babies and young children.
The usefulness of the laser was limitedas its intense light also damaged the fragile upper layer of the skin, causing pain, scars and changes of pigmentation, explains
The challenge was find a way to protect your skin surface, while maximizing the destruction of the deep blood vessels responsible for the mark.
Nelson and his colleagues, postdoctoral researcher Thomas Milner and the Norwegian engineer Lars Svaasandtried several solutions: ice cubes, cold running water and even cooled metal plates applied to the skin before exposure to the laser.
However, all these methods proved to be too complicated and, even worse, also cool target blood vessels, reducing the effectiveness of the laser.
“We needed something that could cool the surface of the skin extremely quickly, in perfect thermal contact, and that disappeared in an instant — all in fractions of a second”, recalls Nelson, in a post on the UC Irvine website.
“It was then that it came to my mind an image of a baseball game”, explains the American surgeon.
During dinner on a Friday, Nelson commented to his two colleagues that when a batsman was hit in the foot or ankle by a ball, the masseur would leave the dugout and sprayed ethyl chloride on the injured area to alleviate the pain.
The three researchers agreed that this type of spray cooling it could work with lasersas long as the cryogenic agent evaporates very quickly and affect only the most superficial layer of the skin.
Over the weekend, Milner and Svaasand developed several ideas on how to apply the concept. The following Monday, they went to Pep Boys, a car parts, buy a fuel injection valve from a Toyota Camry, a clamp and air conditioning refrigerant fluid.
With these parts, the three researchers built the first prototype of the Dynamic Cooling Device (Dynamic Cooling Device) — which would revolutionize laser treatment techniques.
To determine the ideal cryogenic jet duration and the interval between the end of spraying and laser firing, the three tested the device on themselvessaid Nelson. “We still have scars on our arms that prove it”,
“It was a very simple construction,” explains Milner. “And that’s the beauty of invention: It’s simple and works perfectly”.
The device is built into the laser handpiece and sprays a substance onto the skin non-flammable and ecologically safereplacement for freon, which forms a liquid film at -60 °C.
This film evaporates almost immediately and, milliseconds later, the skin is exposed to the laser. The process is repeated before each light pulse.
“As the sprays are so shortthe cooling remains confined to the most superficial layer of the skin and does not affect the deeper blood vessels responsible for the vascular spot,” explains Nelson. “This allows for much higher doses of laser light to be used, while reducing skin damage and pain for the patient.”
Between 2001 and 2010, the device was among the ten most profitable inventions from the University of California — having achieved second and third place in 2005 and 2006, respectively. To date, generated almost 60 million dollars in royalties to UC Irvine.
“Technology has made it possible early, painless, safe and effective treatment of port-wine stains and other disfiguring vascular marks in babies and young children, in ways that Tom, Lars and I could never have imagined,” concluded Nelson. “That’s what I’m most proud of”.
