Evaluating clinical near-infrared surgical camera systems with a view to optimizing operator and computational signal analysis

Abstract

. Significance As clinical evidence on the colorectal application of indocyanine green (ICG) perfusion angiography accrues, there is also interest in computerizing decision support. However, user interpretation and software development may be impacted by system factors affecting the displayed near-infrared (NIR) signal. Aim We aim to assess the impact of camera positioning on the displayed NIR signal across different open and laparoscopic camera systems. Approach The effects of distance, movement, and target location (center versus periphery) on the displayed fluorescence signal of different systems were measured under electromagnetic stereotactic guidance from an ICG-albumin model and in vivo during surgery. Results Systems displayed distinct fluorescence performances with variance apparent with scope optical lens configuration (0 deg versus 30 deg), movement, target positioning, and distance. Laparoscopic system readings fitted inverse square function distance-intensity curves with one device and demonstrated a direction dependent sigmoid curve. Laparoscopic cameras presented central targets as brighter than peripheral ones, and laparoscopes with angled optical lens configurations had a diminished field of view. One handheld open system also showed a distance-intensity relationship, whereas the other maintained a consistent signal despite distance, but both presented peripheral targets brighter than central ones. Conclusions Optimal clinical use and signal computational development requires detailed appreciation of system behaviors.

Indocyanine green (ICG) fluorescence technology in pediatric robotic surgery

“…Upon excitation with light at a specific wavelength in the NIR spectrum emitted from a particular light source or NIR laser device, ICG becomes fluorescent. This fluorescence can be captured by dedicated optics and cameras and then displayed on a video monitor, enabling visualization of the anatomical structures of interest where the dye has accumulated, such as bile ducts, vessels, lymph nodes, lymphatics, tumors, and organs like kidney or spleen [ 8 – 10 ].…”

“…More recently, the utilization of ICG fluorescence technology has seen a remarkable surge. This is attributed to the availability of various camera systems from different brands, leading to an exponential increase in its applications in both adults and children [ 8 – 10 ].…”

“…From a technical perspective, fluorescence is generated by a specific fluorophore called indocyanine green (ICG) when it is excited using near-infrared (NIR) light, and it is visualized using specific cameras and optics [ 8 – 10 ]. Upon intravenous injection, ICG rapidly binds to various carriers, primarily albumin.…”

Clinical and computational development of a patient-calibrated ICGFA bowel transection recommender

“…Although clinical trials supporting ICGFA are accumulating, issues relating to interpretation variation and equipment behaviour may undermine clinical uptake [ 8 , 11 ]. Indeed, the lack of standardised objective interpretation may have contributed to some studies failing to show significant benefit [ 34 , 35 ].…”

“…While this work also demonstrates assessment of both large and small bowel, recommendations were only based on comparisons of the same bowel type. Indeed, simultaneous on-screen comparisons save time compared to the proposed method, however, the NIR signal in the periphery of the screen is weaker and this may complicate visual and quantitative comparisons [ 11 , 12 ] of bowel in different potions of the screen. It may also be impractical to visualise two distinct colonic segments in this way.…”