Multicolor fluorescence imaging using a single RGB-IR CMOS sensor for cancer detection with smURFP-labeled probiotics

Abstract

A multicolor fluorescence imaging device was recently developed for image-guided surgery. However, conventional systems are typically bulky and function with two cameras. To overcome these issues, we developed an economical home-built fluorescence imaging device based on a single RGB-IR sensor that can acquire both color and fluorescence images simultaneously. The technical feasibility of RGB-IR imaging was verified ex vivo in chicken breast tissue using fluorescein isothiocyanate (FITC), cyanine 5 (Cy5), and indocyanine green (ICG) as fluorescent agents. The minimum sensitivities for FITC, Cy5, and ICG were 0.200 µM, 0.130 µM, and 0.065 µM, respectively. In addition, we validated the fluorescence imaging of this device in vitro during a minimally invasive procedure using smURFP-labeled probiotics, which emit a spectrum similar to that of Cy5. Our preliminary study of the ex vivo tissue suggests that Cy5 and ICG are good candidates for deep tissue imaging. In addition, the tumor-specific amplification process was visualized using cancer cells incubated with probiotics that had been labeled with a fluorescent protein. Our approach indicates the potential for in vivo screening of tumors in rodent tumor models.

Global health open-source goggles for fluorescence-guided surgery

“…Most FGS systems employ multiple cameras with optical filters and beamsplitter to achieve coaligned visible and NIR imaging ( 6, 24 ). A potentially simpler approach for real-time overlay of white light reflectance images with fluorescence images is using a single sensor coupled with a modified 4-channel RGB-IR Bayer filter ( 6, 19, 25 ). However, these off-the-shelf RGB-IR cameras such as the See3Cam_CU40 are not optimized for compactness and often go out of production, creating a fairly bulky (27cm 3 ) unreliable system that is challenging to integrate into a wearable device.…”

“…We previously introduced the GAINS system as an ergonomic real-time FGS system that overcame limitations of bulky, expensive, cart-based fluorescence imaging guidance systems by reducing cost, complexity, and hardware footprint( 17, 18, 29 ). Other groups have introduced complementary innovations, including multispectral sensors that obviate the need for separate white light and NIR cameras( 19, 25 ), stereoscopic multimodality systems( 21, 22, 27, 30 ), and optical methods for ensuring coalignment between the surgeon’s eyes and camera FOV( 31 ). Despite the innovations introduced by the GAINS and other more recent systems, FGS HMD systems continue to be wall-powered, complex, expensive, relatively bulky, and replete with significant mismatch between the camera and the surgeon’s view, which makes their adoption in low-resource settings more challenging.…”

“…Most FGS systems employ multiple cameras with optical filters and beamsplitter to achieve coaligned visible and NIR imaging (6,24). A potentially simpler approach for real-time overlay of white light reflectance images with fluorescence images is using a single sensor coupled with a modified 4-channel RGB-IR Bayer filter (6,19,25).…”

Global health open-source goggles for fluorescence-guided surgery

“…We previously introduced the GAINS system as an ergonomic real-time FGS system that overcame limitations of bulky, expensive, cart-based uorescence imaging guidance systems by reducing cost, complexity, and hardware footprint 17,18,28 . Other groups have introduced complementary innovations, including multispectral sensors that obviate the need for separate white light and NIR cameras 19,29 , stereoscopic multimodality systems 21,22,26,30 , and optical methods for ensuring coalignment between the surgeon's eyes and camera FOV 31 . Despite the innovations introduced by the GAINS and other more recent systems, FGS HMD systems continue to be wall-powered, complex, expensive, relatively bulky, and replete with signi cant mismatch between the camera and the surgeon's view, which makes their adoption in low-resource settings more challenging.…”

“…Most FGS systems employ multiple cameras with optical lters and beamsplitter to achieve coaligned visible and NIR imaging 6,25 . A potentially simpler approach for real-time overlay of white light re ectance images with uorescence images is using a single sensor coupled with a modi ed 4-channel RGB-IR Bayer lter 6,19,29 . However, these off-the-shelf RGB-IR cameras such as the See3Cam_CU40 are not optimized for compactness and often go out of production, creating a fairly bulky (27cm 3 ) unreliable system that is challenging to integrate into a wearable device.…”