Breakthrough in Brain Blood Flow Surgery Could Save Lives

Researchers at The University of Texas at Austin have created a new technique called sinusoidal intensity modulation speckle imaging (SIMSI) to monitor blood flow during neurosurgery. The method uses standard camera hardware and dynamic light scattering physics to provide quantitative, physically meaningful measurements of blood flow across a wide field of view without high-speed cameras or invasive procedures. SIMSI builds on laser speckle contrast imaging (LSCI), which has been used in research but only offers relative measurements. By adding precise sinusoidal modulation to laser illumination during camera exposure, SIMSI captures fast blood flow dynamics that conventional LSCI misses. This allows surgeons to track blood flow in real time, reducing risks of permanent damage during operations like brain surgery or cardiac procedures. Andrew Dunn, a professor in the Cockrell School of Engineering’s Department of Biomedical Engineering, led the study published in *Proceedings of the National Academy of Sciences*. He noted that SIMSI could improve surgical decision-making, stroke treatment, and research into conditions like dementia and traumatic brain injury. The technology was first tested in the operating room in 2010, and Dunn’s lab has spent 25 years refining it. The team also commercialized the technology through UT Austin’s Discovery to Impact hub, licensing it to Dynamic Light, an Austin-based medical device startup. SIMSI’s ability to provide fast, quantitative blood flow data could make advanced imaging more accessible in clinical settings. Beyond neurosurgery, SIMSI may enhance monitoring during cardiac surgery, reconstructive procedures, and stroke care. Hengfa Lu, a postdoctoral fellow in Dunn’s lab, explained that the technique recovers fast blood flow dynamics by modulating illumination and using a new imaging model, offering clearer insights into tissue function. The research represents a significant advancement in intraoperative monitoring, potentially saving lives by preventing blood flow interruptions that could cause permanent damage.