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Surgeons operating laparoscopically often have to rely upon subjective visual cues for complete oncological control and
avoiding tumor violation or iatrogenic injury to critical tissues. A laparoscopic imaging tool to allow assessment of
tumor margin or identification of anatomical structures buried under the layer of tissue being dissected is desirable to
probe tissue contrast at a few millimeters depth, visualize over the lateral view for resection guidance, have a non-microscopic
field-of-view (FOV) adequate for rapid survey of the resection site, and form the image in real-time.
Probing light diffusely propagated through tissue provides sub-surface sensitivity, but the image formation generally
involves intense computation that may be costly to intraoperative time-frame. Projecting these modalities
laparoscopically to sample subsurface tissue heterogeneity over a non-microscopic FOV for rapid site-survey has been
challenging. We demonstrate a laparoscopic applicator probe and a method thereof for real-time en-face mapping of
near-surface heterogeneity for potential use towards intraoperative margin assessment. The probe fits a 12mm port and
houses at 128 copper-coated 750μm fibers that form radially alternating illumination (70 fibers) and detection (58 fibers)
channels. By simultaneously illuminating the 70 source channels of the laparoscopic probe that is in contact with a
scattering medium and concurrently measuring the light diffusely propagated to the 58 detector channels, the presence of
near-surface optical heterogeneities can be resolved in an en-face 9.5mm field-of-view in real-time. Visualization of
subsurface margin of strong attenuation contrast at a depth up to 3mm is demonstrated at a frame rate of 1.25Hz.
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