LED-Based Time-Multiplexed RGB and FLT Endoscopy Imaging with a Time-Gated Camera

Fluorescence-guided surgery is a significant advancement in medical imaging, particularly for distinguishing malignant from healthy tissue during cancer surgery. Recent advancements in endoscopy technology and fluorescence-lifetime (FLT) imaging can provide better insight into identifying abnormal tissues during surgery than white light endoscopy imaging. Current imaging systems used in fluorescence-guided surgery are primarily designed to provide surgeons with a combined view of natural color (RGB) images and fluorescence overlays. These systems typically rely on an RGB camera, incapable of FLT imaging. Our novel approach sequentially illuminates the scene with red, green, and blue light pulses and Near Infrared (NIR) pulses, captured selectively with a single fast time-gated camera. The camera is synchronized to the pulsed illumination and positions its gate windows to capture only one of the illumination pulses; afterwards, it overlays the NIR fluorescence lifetime image on the natural color image. The VUB-ETRO team developed the tauCAMTM camera based on Current-Assisted Photonic Sampler (CAPS) image sensor technology, which intends to offer real-time FLT imaging, particularly in the NIR area. This paper presents an LED-based time-multiplexing RGB + FLT endoscopy imaging with tauCAMTM, designed to enhance visualization in real-time surgical settings. By combining RGB and FLT imaging, surgeons could receive comprehensive insights into tissue characteristics, supporting precise interventions.