A light-weight near infrared fluorescence endoscope based on a single color camera: a proof-of-concept study (original) (raw)
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Sensors
We developed a single-camera-based near-infrared (NIR) fluorescence imaging device using indocyanine green (ICG) NIR fluorescence contrast agents for image-induced surgery. In general, a fluorescent imaging system that simultaneously provides color and NIR images uses two cameras, which is disadvantageous because it increases the imaging head of the system. Recently, a single-camera-based NIR optical imaging device with quantum efficiency partially extended to the NIR region was developed to overcome this drawback. The system used RGB_NIR filters for camera sensors to provide color and NIR images simultaneously; however, the sensitivity and resolution of the infrared images are reduced by 1/4, and the exposure time and gain cannot be set individually when acquiring color and NIR images. Thus, to overcome these shortcomings, this study developed a compact fluorescent imaging system that uses a single camera with two complementary metal–oxide semiconductor (CMOS) image sensors. Sensit...
Bioinspired color-near infrared endoscopic imaging system for molecular guided cancer surgery
Journal of Biomedical Optics, 2023
Fluorescently guided minimally invasive surgery is improving patient outcomes and disease-free survival, but biomarker variability hinders complete tumor resection with single molecular probes. To overcome this, we developed a bioinspired endoscopic system that images multiple tumor-targeted probes, quantifies volumetric ratios in cancer models, and detects tumors in ex vivo samples. Aim: We present a new rigid endoscopic imaging system (EIS) that can capture color images while simultaneously resolving two near-infrared (NIR) probes. Approach: Our optimized EIS integrates a hexa-chromatic image sensor, a rigid endoscope optimized for NIR-color imaging, and a custom illumination fiber bundle. Results: Our optimized EIS achieves a 60% improvement in NIR spatial resolution when compared to a leading FDA-approved endoscope. Ratio-metric imaging of two tumor-targeted probes is demonstrated in vials and animal models of breast cancer. Clinical data gathered from fluorescently tagged lung cancer samples on the operating room's back table demonstrate a high tumor-to-background ratio and consistency with the vial experiments. Conclusions: We investigate key engineering breakthroughs for the single-chip endoscopic system, which can capture and distinguish numerous tumor-targeting fluorophores. As the molecular imaging field shifts toward a multi-tumor targeted probe methodology, our imaging instrument can aid in assessing these concepts during surgical procedures.
Journal of Biomedical Optics, 2015
Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use.
Journal of Instrumentation, 2019
A novel hand-held hybrid optical-gamma camera (HGC) has previously been described that is capable of displaying co-aligned images from both modalities in a single imaging system. Here, a dedicated NIR imaging system for NIR fluorescence surgical guidance has been developed for combination with the HGC . This work has evaluated the performance of two NIR fluorescence imaging systems using phantom studies, various fluorophores and various experimental configurations. The threshold detectable concentration of ICG and 800CW dyes were investigated for both systems. Bespoke lymph node phantoms simulating metastases and tissue-like layers were constructed to evaluate the detection capability. ICG could be detected at a minimum concentration of 1 μM for each camera. The lower thresholds for 800CW were 10−2 and 10−3 μM for the modified and NIR cameras, respectively. Both cameras were unable to detect small-sized targets within a 3 mm depth, but were able to identify larger targets as deep as 7 mm. Further improvements are required to optimise the NIR-fluorescence systems for subsequent combination with the HGC to undertake dual gamma-NIR fluorescence intraoperative imaging
Capsule Endoscopy Compatible Fluorescence Imager Demonstrated Using Bowel Cancer Tumours
IEEE Sensors Journal, 2020
We demonstrate a proof of concept highly miniaturised fluorescence imager and its application to detecting cancer in resected human colon cancer tissues. Fluorescence imaging modalities have already been successfully implemented in traditional endoscopy. However, the procedure still causes discomfort and requires sedation. Wireless fluorescence capsule endoscopy has the potential to improve diagnostic accuracy with less inconvenience for patients. In this paper we present a 5 mm x 6 mm x 5 mm optical block that is small enough to integrate into a capsule endoscope. The block integrates ultrathin filters for optical isolation and was successfully integrated with a sensitive CMOS SPAD array to detect green fluorescence from Flavin Adenine Dinucleotide (FAD), which is an endogenous fluorophore responsible for autofluorescence in human tissues, and fluorescence from the cancer selective molecular probe ProteoGREEN TM-gGlu used to label colorectal cancer cells. In vitro studies were validated using a commercial Modulus TM Microplate reader. The potential use of the device in capsule endoscopy was further validated by imaging healthy and malignant resected human tissues from the colon to detect changes in autofluorescence signal that are crucial for cancer diagnosis.
Journal of Biomedical Optics, 2014
The near-infrared (NIR) fluorescence signal in the 700 to 900 nm from molecular probes used in fluorescence image-guided surgery (FIGS) is usually weak compared to the NIR component from white light-emitting diode surgical light, which is typically switched off during FIGS to enhance the molecular fluorescence contrast of the image. We propose a simple solution to this critical issue in FIGS by removing NIR light from surgical light with a low cost commercial 3M cool mirror film 330.
Development and evaluation of a light-emitting diode endoscopic light source
Advanced Biomedical and Clinical Diagnostic Systems X, 2012
Light-emitting diode (LED) based endoscopic illumination devices have been shown to have several benefits over arclamp systems. LEDs are energy-efficient, small, durable, and inexpensive, however their use in endoscopy has been limited by the difficulty in efficiently coupling enough light into the endoscopic light cable. We have demonstrated a highly homogenised lightpipe LED light source that combines the light from four Luminus LEDs emitting in the red, green, blue and violet using innovative dichroics that maximise light throughput. The light source spectrally combines light from highly divergent incoherent sources that have a Lambertian intensity profile to provide illumination matched to the acceptance numerical aperture of a liquid light guide or fibre bundle. The LED light source was coupled to a standard laparoscope and performance parameters (power, luminance, colour temperature) compared to a xenon lamp. Although the total illuminance from the endoscope was lower, adjustment of the LEDs' relative intensities enabled contrast enhancement in biological tissue imaging. The LED light engine was also evaluated in a minimally invasive surgery (MIS) box trainer and in vivo during a porcine MIS procedure where it was used to generate 'narrowband' images. Future work using the violet LED could enable photodynamic diagnosis of bladder cancer.
We have developed a near-infrared (NIR) fluorescence goggle system based on the complementary metal-oxide-semiconductor active pixel sensor imaging and see-through display technologies. The fluorescence goggle system is a compact wearable intraoperative fluorescence imaging and display system that can guide surgery in real time. The goggle is capable of detecting fluorescence of indocyanine green solution in the picomolar range. Aided by NIR quantum dots, we successfully used the fluorescence goggle to guide sentinel lymph node mapping in a rat model. We further demonstrated the feasibility of using the fluorescence goggle in guiding surgical resection of breast cancer metastases in the liver in conjunction with NIR fluorescent probes. These results illustrate the diverse potential use of the goggle system in surgical procedures.
Coherent Narrow-Band Light Source for Miniature Endoscopes
IEEE Journal of Selected Topics in Quantum Electronics
In this work, we report the successful implementation of a coherent narrow-band light source for miniature endoscopy applications. An RGB laser module that provides much higher luminosity than traditional incoherent white light sources is used for illumination, taking advantages of the laser light's high spatial coherence for efficient light coupling. Notably, the narrow spectral band of the laser light sources also enables spectrally resolved imaging, to distinguish certain biological tissues or components. A monochrome CMOS camera is employed to synchronize with the time lapsed RGB laser module illumination for color image acquisition and reconstruction, which provides better spatial resolution than a color CMOS camera of comparable pixel number, in addition to spectral resolving.