This PDF file contains the front matter associated with SPIE Proceedings Volume 11937, including the Title Page, Copyright information, Table of Contents, and Conference Committee listings.

Real-time intraoperative blood perfusion monitoring is an important aid for avoiding the anastomotic leaks (AL) in laparoscopic (‘keyhole’) surgery which in turn reduces patients’ length of hospitalization and healthcare cost. The occurrence of AL at the rate of 11% to 15% (in rectal surgery, AL also varies with the surgical site) is a burden to patients and the healthcare system. Visualization of intraoperative surgical regions of interest is conducted by intravenous injection of the fluorescent contrast agent - indocyanine green (ICG). However, intravenously ICG administration is limited by non-linear fluorescence intensity with concentration, risk of an allergic reaction, and aggregation in aqueous solution. The fluorescence persists limits the frequency of repeated imaging and real-time assessments. Therefore, an alternative approach allowing label-free visualization would be advantageous. To this end, laser speckle contrast imaging (LSCI) is a potential alternative technique for real-time, label-free, and full-field blood flow monitoring techniques. We have developed a prototype medical device using a commercial rigid endoscope that allowed simultaneous white light imaging as well as blood perfusion monitoring using LSCI. The prototype was assessed for simultaneous white-light endoscopy and flow-monitoring of objects, such as; colored cardboard, a motility standard, occluded fingers, and oral mucosa of the human mouth - all positioned at various distances (e.g., 50mm, 70mm, and 100mm) from endoscope tip. We envision that this bimodal, label-free prototype allowing simultaneous blood flow measurement and white light imaging capability will prove a valuable tool for laparoscopic surgeries.

Acute Respiratory Distress Syndrome (ARDS) is a severe form of lung injury characterized by hypoxemia. ARDS is estimated to affect at least 190,000 patients per year in the United States. The median time for ARDS onset is 48 hours after hospital admission. The early assessment of the ARDS due to smoke inhalation injury (SII) plays a vital role in facilitating appropriate treatment strategies and improved clinical outcomes. Optical coherence tomography (OCT) may be used as an effective diagnostic tool in quantifying the physiological changes in the airway after smoke inhalation injury. The objective of this study is to develop and evaluate a deep-learning technique to predict and early uncover (within 24 hours) ARDS in a pig model based on the information obtained from the OCT images. A convolutional neural network (CNN) is modeled to train and classify the pig airway images. The early prediction would help clinicians in the accurate diagnosis of ARDS which is of great clinical value.

Acute respiratory distress syndrome (ARDS) is a form of lung injury that is associated with inflammation and increased permeability in the lung. It is characterized by acute arterial hypoxemia. The accurate assessment of the airway damage due to smoke inhalation injury (SII) plays a vital role in facilitating appropriate treatment strategies and improved clinical outcomes. This study evaluates the efficiency and accuracy of a trained neural network in segmenting the pig airway images which is used in the assessment of ARDS caused by smoke inhalation injury (SII). The neural network is modeled after the U-net convolutional neural network and the segmentation accuracy is calculated.

Multiple clinically approved dyes and several new dyes currently in clinical studies are used for fluorescence-guided surgery, diagnosis and imaging. These present a wide range of absorption and emission spectra and create a demand for endoscopic illumination sources with multiple wavelengths. Fluorescent imaging with simultaneous white light overlay image benefit from laser light sources for fluorescence excitation and white light illumination to allow for easy spectral filtering on imaging side. Emerging applications with imaging of two or more complementary fluorescent dyes further adds to desire for a configurable multi-wavelength endoscopic light source. The multi-wavelength configurable and cloud connected oncology laser platform Modulight ML7710 was developed further to accommodate the light engine requirements of real-time multi-wavelength endoscopic fluorescence imaging. The configurable medical illumination platform enables simultaneous multi-wavelength fluorescence excitation with wide dynamic range and color balance adjustable RGB white light illumination. Multi-wavelength light output functionality was further developed to support industry standard endoscopic light guides without the need of additional external optical elements. Laser light sources for imaging typically suffer from unwanted speckle patterns. This issue is solved with internal speckle remover which greatly reduces speckle contrast even when used with high-speed imaging applications. The platform also offers possibility for spectral measurement of fluorescence from the target to the supplement or facilitate high-resolution imaging. The configurable touchscreen user interface allows for simple application for specific operation and cloud-based connectivity enables modern configuration, data logging, planning and control with platform for future machine learning and AI analysis.

One major advantage of multiphoton microscopy (MPM) is that it can image below tissue surface and produce a stack of images showing sample structure at various depths. A miniature objective with depth scanning capability is needed for MPM endoscopy. Spherical aberration may be induced when changing the focusing depth during multiphoton microscope depth scanning, thus limiting the range over which images may be acquired. A specially designed miniature objective that minimizes spherical aberration across large range of focusing depths is presented. Simulations show that the 0.53 numerical aperture design can achieve on-axis diffraction limited focusing in water for depths from 0 μm to just over 1400 μm and a diffraction limited field of view of up to 290 μm for a 790 nm laser. In experiment, our multiphoton microscope demonstrates a field of view of 64 μm by 100 μm and a depth scanning range of 440 μm, limited by the scanning hardware. Depth scanning capability is confirmed by imaging 0.1 μm diameter fluorescent beads across the 440 μm range. Biological samples to a depth of 150 μm are imaged using the custom objective; the imaging depth is mainly limited by the absorption and scattering of the sample.

Imaging through a multimode fiber (MMF) with a spatial-resolution beyond the diffraction limit has recently been demonstrated using computational super-resolution methods. We performed a modelling study to assess the performance of a compressed image reconstruction algorithm, Basis Pursuit, using different illuminations. In addition to the increased speed due to the reduced number of measurements, we characterized other potential benefits with respect to robustness to noise and resilience to fiber bending when using compressed imaging with optimized illuminations.

Optical fibres have revolutionised clinical practice in the form of the optical endoscope, and are now providing the framework for an entirely new endoscopic paradigm: all-optical ultrasound. Ultrasonic techniques, and in particular those based on the opto-acoustic effect of Brillouin scattering, present a number of advantages compared to purely optical techniques. High contrast imaging can be achieved without the use of fluorescent labels, elastic properties of the specimen can be quantified, lateral resolution is provided by optics, and axial resolution is provided by sub-optical wavelength non-destructive phonons. Here we present an optical fibre-based time resolved Brillouin scattering system, called a phonon probe, which is capable of measuring nanometric topography and elastic properties in parallel from microscopic samples. We also demonstrate that our technique is inherently compatible with standard coherent imaging bundles, which will drive the technology towards future in vivo applications.