Biomedical Engineering Paper Featured in Journal of Biomedical Optics

Microvascular Therapeutics and Imaging Laboratory has paper on birthmark removal technoogy published

Bernard Choi, Ph.D., assistant professor of biomedical engineering at The Henry Samueli School of Engineering and Owen Yang, a third-year graduate student in the Samueli School, teamed with David Cuccia, CEO of Modulated Imaging, Inc., on a project in the Microvascular Therapeutics and Imaging Laboratory at the Beckman Laser Institute at UC Irvine to improve the removal of port wine stain birthmarks.  The findings of the group have led to a paper published in Journal of Biomedical Optics.

Each year, there are approximately 12,000 babies born with port wine stain birthmarks, which consist of dilated blood vessels that appear as red or purple discolorations on the surface of the skin.  The primary method of treatment is to use laser surgery, typically with a pulsed dye laser, to damage the abnormal blood vessels while leaving the surrounding tissue intact.  Repair of these damaged vessels hopefully results in regrowth of normal blood vessels.  However, only about 60 percent of patients experience any lightening in color, and complete removal is still a rarity.

The research team hypothesized that a primary reason for these poor treatment outcomes is the incomplete stoppage of blood flow after laser therapy.  To give the clinician instantaneous feedback during laser surgery, they developed a non-invasive monitoring instrument based on the principles of laser speckle imaging (LSI).  LSI involves illuminating the skin surface with laser light and measuring the resulting ‘speckle’ pattern with a camera.

The group applied image-processing techniques to convert these speckle patterns into maps of blood flow.  The use of a graphics processing unit (GPU) enables the processing of data to be quick enough to achieve real-time processing and display blood-flow maps on a computer screen.  Looking at a blood flow map, the laser surgeon can analyze areas that still have persistent blood flow near the surface of the skin and adjust.  The group believes that this real-time LSI system can be deployed for image-guided surgery and allow for improved treatment outcomes for port wine stain birthmarks and other microvasculature diseases.