Compact instrument for fluorescence image-guided surgery

Abstract

Abstract. Fluorescence image-guided surgery ͑FIGS͒ is an emerging technique in oncology, neurology, and cardiology. To adapt intraoperative imaging for various surgical applications, increasingly flexible and compact FIGS instruments are necessary. We present a compact, portable FIGS system and demonstrate its use in cardiovascular mapping in a preclinical model of myocardial ischemia. Our system uses fiber optic delivery of laser diode excitation, custom optics with high collection efficiency, and compact consumer-grade cameras as a low-cost and compact alternative to open surgical FIGS systems. Dramatic size and weight reduction increases flexibility and access, and allows for handheld use or unobtrusive positioning over the surgical field. Fluorescence imaging is increasingly being employed for surgical guidance, used to minimize iatrogenic damage, expedite surgical procedures, and enhance surgical efficiency, with utility in various clinical fields.1-3 Applications of fluorescence image-guided surgery ͑FIGS͒ include sentinel lymph node mapping, 2,3 assessing coronary artery bypass graft patency, 4 identifying tumors intraoperatively, 5,6 and minimizing the risk of iatrogenic bile duct injury.7 Many of these applications, such as imaging of lymphatics or vasculature, are enabled by nontargeted fluorescent contrast agents such as indocyanine green or methylene blue ͑MB͒.Contrast agents emitting in the NIR region of the optical spectrum ͑700 to 1000 nm͒ provide several advantages over agents in the visible region. 8 Tissue constituents that dominate absorption of light in the visible have absorption minima in the red to NIR. Moreover, there is a dramatic decrease in scattering in the NIR relative to visible wavelengths. The reduced absorption and scattering results in less light attenuation and thus deeper penetration. Imaging in the NIR also minimizes background, as most endogenous fluorescent species emit in the visible spectrum. 9 In FIGS, one channel typically images the fluorescence emission, while the other channel simultaneously captures a color video of the surgical area. Thus, emission in the NIR also allows for minimal spectral overlap between the color and fluorescence channels, resulting in higher color fidelity and higher fluorescence collection efficiency. FIGS instrumentation has been developed for both open and minimally invasive surgeries.2-7 Several of these instruments feature only a single ͑fluorescence͒ channel, 2,4,6,7 or have a relatively large footprint. [2][3][4] To improve access and increase the clinical utility of FIGS, particularly for open surgical applications, 3 the size of existing imaging systems has to be reduced for greater flexibility and mobility. Here we describe the development of a compact dual-mode imaging probe and demonstrate its use in cardiovascular surgery in a preclinical model.Our strategy for size reduction addresses illumination, detection, and optics. First, the system uses fiber optic delivery of both excitation and illumination. Conventional systems often ho...

Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system

“…The footprint for these devices is typically large, and the high cost associated with these systems limits the dissemination of the systems. Minimally invasive surgical procedures, such as endoscopy 14 and laparoscopy, [15][16][17] have also benefited from NIR fluorescence. Optimized NIR rigid probes have been used to simultaneously acquire fluorescence and visible spectrum information and to present this information on an overlaying monitor.…”

Design and characterization of an optimized simultaneous color and near-infrared fluorescence rigid endoscopic imaging system

“…In terms of device developments, there have been significant advances in designing optical imaging systems used for IGS resulting in compact, ergonomic, and sensitive imaging systems. [14][15][16] These systems have, however, been designed for invasive, open surgical procedures with lens, and illumination designs allowing imaging over wide fields of view (typically in the hundreds of centimeters squared). Many fluorescence imaging systems have successfully reached the clinic and have been used during first-in-human trials relying on off-label use of U.S. FDA approved contrast agents.…”

Compact wearable dual-mode imaging system for real-time fluorescence image-guided surgery

“…Thus, white light reflectance imaging and fluorescence imaging are often integrated together because they provide complementary information. [6][7][8][9][10][11] Two cameras with different optics are commonly used to capture white light reflectance and NIR fluorescence images separately, but the system is relatively bulky and the fields of view (FOV) are not identical for two imaging modalities. 6 Recently, dual-mode imaging systems with a single sensor have been developed to reduce system complexity.…”

“…[6][7][8][9][10][11] Two cameras with different optics are commonly used to capture white light reflectance and NIR fluorescence images separately, but the system is relatively bulky and the fields of view (FOV) are not identical for two imaging modalities. 6 Recently, dual-mode imaging systems with a single sensor have been developed to reduce system complexity. 12,13 Another approach is to capture reflectance image and fluorescence image sequentially with a single camera by modulating the illumination spectrum.…”

“…[1][2][3][4][5][6][7][8][9][10][11] Indocyanine green (ICG), as a dye for fluorescence imaging, has been used in retinal angiographs for more than 50 years. 2 In some clinical and surgical applications, ICG imaging is still a relatively new imaging method.…”