Dual-display laparoscopic laser speckle contrast imaging for real-time surgical assistance

Laser speckle contrast imaging (LSCI) utilizes the speckle pattern of a laser to determine blood flow in tissue. Current approaches to its use in the clinical setting require a camera system with a separate, external laser source, making it unsuitable for minimally invasive surgery (MIS). With blood flow visualization, bowel viability, for example, can be determined. Thus, LSCI can be a valuable tool in gastrointestinal surgery. In this work, we develop a first-of-its-kind dual-display laparoscopic vision system integrating LSCI with a commercially available 10mm rigid laparoscope without the need for an externally positioned laser source. Designed for minimally invasive surgery, our system permits color RGB, label-free vasculature imaging, and fused display modes. A graphics processing unit (GPU) accelerated algorithm enables the real-time display of three different modes at the surgical site. We demonstrate the capability of our system to image relative flow rates in a microfluidic phantom with channels as small as 200$\mu$m at a working distance of 5cm from the laparoscope tip to phantom surface. Using our system, we reveal early changes in bowel perfusion invisible to standard color vision during a rat bowel occlusion model. Furthermore, we apply our system for the first time to image intestinal vasculature during a minimally invasive surgery in a swine.