Fully Integrated Ultra-thin Intraoperative Micro-imager for Cancer Detection Using Upconverting Nanoparticles

Area of Science:

• Biomedical Engineering
• Surgical Technology
• Nanotechnology

Background:

• Intraoperative detection of microscopic residual disease (MRD) is crucial for cancer surgery outcomes.
• Current intraoperative imagers are bulky, limiting integration into minimally invasive procedures.
• Need for miniaturized, highly sensitive imagers for modern surgical workflows.

Purpose of the Study:

• To engineer a chip-scale intraoperative micro-imager array for MRD detection.
• To develop a lens- and filter-free imaging platform for seamless surgical integration.
• To leverage upconverting nanoparticles for enhanced tissue visualization.

Main Methods:

• Engineered a chip-scale imager integrated with lanthanide-based alloyed upconverting nanoparticles (aUCNPs).
• Utilized time-resolved imaging on a 36x80-pixel silicon micro-chip (2.3mm x 4.8mm, <100µm thin).
• Incorporated novel pixel architecture for automated background measurement and cancellation.

Main Results:

• Achieved spatial resolution of 71µm on USAF targets.
• Demonstrated background cancellation, improving signal-to-background ratio from 0.4 to 8 in ex vivo tumor imaging.
• Resolved cell clusters as small as 200 cells with a signal-to-background ratio of 4.3.

Conclusions:

• The proposed imaging system offers a scalable, chip-scale, ultra-thin alternative to conventional intraoperative imagers.
• Novel pixel architecture and background correction enable visualization of microscopic residual disease.
• Achieved an ultra-miniaturized form factor critical for intraoperative applications.