NIR-II fluorescence projection technology for augmented-reality surgical navigation.

NIR-II fluorescence imaging provides superior tissue penetration and clarity, yet its clinical use in surgical navigation is hindered by a critical workflow issue. Surgeons must divert their attention between the operative field and external monitors, increasing cognitive load and disrupting procedures. Current strategies have failed to resolve this fundamental problem. Here, we developed a co-axial NIR-II fluorescence projection navigation system to enable real-time, in situ visualization. This system creates an intraoperative augmented reality by directly projecting high-precision, pseudocolored fluorescence images onto the surgical field, spatially integrating functional signals with patient anatomy. Validated through in vitro, in vivo and clinical patient studies, our system eliminates visual field switching, reduces intraoperative distraction and preserves natural stereoscopic vision. This approach represents a paradigm shift toward a more coherent, efficient and ergonomically optimized optical imaging modality for surgical navigation.