Butterfly eyes inspire real-time surgery imaging solution

ECE ILLINOIS visiting scholar Nimrod Missael Garcia Hernandez, along with Associate Professor Viktor Gruev, won two Best Paper Awards at the IEEE International Symposium on Circuits and Systems (ISCAS). These distinctions include the Best Paper Award in the Sensory Circuits and Systems track, and, most impressively, the Best Student Paper Award, chosen among around 800 papers. Gruev, who was the principal investigator for the research, is also affiliated with the Beckman Institute and MNTL.

In their paper, “A 1600 by 1200, 300 mW, 40 fps Multi-Spectral Imager for Near-Infrared Fluorescence Image-Guided Surgery,” Garcia and Gruev introduced a bio-inspired design comprising an artificial multi-spectral sensor. 

Gruev’s previous research examined the mantis shrimp visual system which is capable of seeing polarization. As featured in a PBS video, this unique property was the foundation for new imaging technology that promises to give surgeons the ability to detect cancerous cells earlier. Now, they are taking on a different approach.

“Our sensor monolithically integrates spectral tapetal filters, inspired by the Morpho butterfly's eyes, with photodetectors to realize a single-chip multispectral imager,” said Garcia. More specifically, spectral filtering helps identify key areas with the fluorescent dyes used by the researchers. This is achieved by solely allowing the light from the fluorescence spectra to pass through the pixelated filter. This light is then detected by a photodetector. 

“Our imager has the ability to capture four spatially co-registered spectral bands in real time; three for color detection and one on the near-infrared (NIR) window for fluorophore detection.” This goes to say that each color band is seen in the same field of view, such that the features on the scene are perfectly aligned.

The fluorophore or fluorescent dye can be engineered for numerous uses. This dye can show surgeons in real-time the location of potentially cancerous tissue. Their preclinical and clinical data has demonstrated potential for using the imager in the conventional surgical workflow.

“My experience with this conference has been fantastic; is an excellent place to meet and network with top researchers from all around the globe in the field of circuits and systems,” Garcia said. “The state-of-the-art research presented at ISCAS serves as an opportunity to create new collaborations.”