Engineer's imaging of blood vessels could aid laser treatment

     People seeking to remove a disfiguring Port Wine Stain skin condition may thank a newly graduated University of Texas at Austin doctoral student for a more effective treatment. Jennifer Barton, a biomedical engineer, discovered a way to view and measure tiny blood vessels using a new imaging technique. Her efforts received international attention last year from the International Society for Optical Engineering.

     Port Wine Stain, a blood vessel abnormality, is characterized by red or purple blotches on the skin that can be large and cosmetically undesirable. It can cause considerable social and psychological distress especially in children. As patients age, Port Wine Stain gets raised and bumpy, which can cause mobility problems for affected eyelids or fingers. Current laser treatments consist of a trial and error procedure that lightens the lesions, but often leaves the skin far from its usual tone. Because of large variations in the distribution, depth and diameter of the vessels, no single set of ideal laser settings exists for every treatment.

     Barton obtained a clear image and measurement of blood vessels near the surface of the skin where the vessels create the problem in Port Wine Stain. This accurate picture of the blood vessels, allows laser treatments to become customized to the skin's anatomy, thus making the treatment potentially far more effective.

     Barton's method, Optical Coherence Tomography, is basically a light imaging technique. Noninvasive and painless it consists of illuminating an area of the skin with a laser diode for several seconds. This provides a reflected-light reading of the skin's underlying structure which includes blood vessels in the area. Then she combines a sequence of images to create a three-dimensional representation of the skin's subsurface. The only other method of viewing a patient's skin anatomy this precisely would require examining an actual cross-section of flesh under a microscope.

     “She's taken several difficult concepts and combined them to provide a technique that may aid the treatment of Port Wine Stain,” said her supervisor Dr. Ashley J. Welch, professor of biomedical engineering at UT Austin. “The techniques include the ability to noninvasively image blood vessels in the skin using Optical Coherence Tomography, the ability to model the geometry of blood vessels and to determine the amount of laser light absorbed by the blood vessels, and relate model predictions to actual laser coagulation of blood vessels.”

     Although Optical Coherence Tomography has existed since the early 1990s, Barton applied the imaging technique to an unexplored realm in biomedical engineering. She researched this area for three years and received an award for her work from the International Society for Optical Engineering in 1997. The $7,000 award, the D.J. Lovell Scholarship, is for the “long range contribution ... to optics and optical engineering.”

     So far experiments have been conducted using hamsters. Barton estimates that human trials are at least two years away because of a few technical difficulties yet to be solved.

     Barton earned her B.S. degree in electrical engineering from The University in 1988 and her M.S. degree in electrical engineering from the University of California, Irvine in 1993. She has recently accepted a position at the University of Arizona as an assistant professor.