This PDF file contains the front matter associated with SPIE Proceedings Volume 9313, including the Title Page, Copyright information, Table of Contents, Invited Panel Discussion, and Conference Committee listing.

We present a study to evaluate and compare three near-infrared (NIR) fluorescence imaging systems designed to provide intraoperative guidance around anatomical structures. The three systems adapted specifically for the application of endogenous NIR fluorescence detection were (1) a photomultiplier tube based NIR viewer, (2) a thermoelectrically cooled electron-multiplying charge-coupled device (CCD) camera, and (3) a clinical endoscope CCD camera system. Each system was evaluated on the basis of ease-of-use, cost, and system performance. The cooled CCD camera showed the highest contrast ratio, but is limited in utility by its bulk interface and high cost. The clinical endoscope camera showed flexibility in its field-of-view and provides the benefit of being sterilized to allow easy integration into the surgical suite; however, it exhibits signal nonlinearity that would distort quantitative analysis. The NIR viewer shows optimal performance, exhibiting high spatial resolution, linearity, and sufficient contrast to differentiate between tissue types. This low-cost design proves to be the optimal system for parathyroid detection, offering ease-of-use in a surgical setting while meeting system performance requirements.

Near-infrared (NIR) fluorescent imaging system has been widely used for intraoperative image-guided application. In this paper, we present performance comparison from three compact NIR fluorescence imaging system prototypes with goggle display that we developed for intraoperative guidance: threshold detection based two camera system, feature matching based three cameras system and miniature beam-splitter single camera system. Their performance is evaluated according to sensitivity regarding different ICG concentrations, accuracy of image overlay between NIR-visible channels, compactness and practicability in intraoperative use. The comparison results show great potentials of using these NIR fluorescence imaging systems to improve user experience and surgical outcomes in intraoperative use.

A new superficial wide-field imaging technique is presented, which utilizes high spatial frequency structured illumination to constrain the light sampling volume to a sub-diffuse regime. In this transport regime, the effects of absorption are drastically reduced and the sensitivity to local scattering from ultrastructrual alterations is increased. Absorption independence is validated with multiple experiments including a bovine blood-Intralipid solution matrix and avian tissue with superficial bovine blood. The resulting structured light demodulated images show a complete insensitivity to the blood over Hb concentrations of 0 – 240 μM. Increased sensitivity to ultrastructual changes is demonstrated by imaging avian tissue with controlled morphological alterations including formalin-induced crosslinking. This imaging technique is currently being translated towards intraoperative assessment of breast tumor margins because of its ability to capture an entire lumpectomy margin in a single field of view, insensitivity to confounding surface blood present on lumpectomies, and its inherent scatter signal without the need of any model inversion. Further, a new lumpectomy marking system is introduced that allows for both the surgeon to mark the lumpectomy during excision and optical assessment of the specimen after the margins have been marked. Structured light images acquired intraoperatively of all margins of lumpectomy specimens are presented to show feasibility of clinical translation. Immediate future work will focus on developing a multi-spectral system.

Photopolymerization is a common tool to harden materials initially in a liquid state. A surgeon can directly trigger the solidification of a dental implant or a bone or tissue filler simply by illumination. Traditionally, photopolymerization has been used mainly in dentistry. Over the last decade advances in material development including a wide range of biocompatible gel- and cement-systems open up a new avenue for in-situ photopolymerization.

However, at the device level, surgical endoscopic probes are required. We present a miniaturized light probe where a photoactive material can be 1) mixed, pressurized and injected 2) photopolymerized or photoactivated and 3) monitored during the chemical reaction. The device enables surgeries to be conducted through a hole smaller than 1 mm in diameter.

Beside basic injection mechanics, the tool consists of an optical fiber guiding the light required for photopolymerization and for chemical analysis. Combining photorheology and fluorescence spectroscopy, the current state of the photopolymerization is inferred and monitored in real time. Biocompatible and highly tuneable Poly-Ethylene-Glycol (PEG) hydrogels were used as the injection material.

The device was tested on a model for intervertebral disc replacement. Gels were successfully implanted into a bovine caudal model and mechanically tested in-vitro during two weeks. The photopolymerized gel was evaluated at the tissue level (adherence and mechanical properties of the implant), at the cellular level (biocompatibility and cytotoxicity) and ergonomic level (sterilization procedure and feasibility study).

This paper covers the monitoring aspect of the device.

Pneumoperitoneum is the beginning procedure of laparoscopy to enlarge the abdominal cavity in order to allow the surgical instruments to insert for surgical purpose. However, the insertion of Veress needle is a blind fashion that could cause blood vessels or visceral injury without attention and results in undetectable internal bleeding. Seriously it may cause a life-threatened complication. We have developed a method that can monitor the tissue reflective spectrum, which can be used for tissue discrimination, in real time during the puncture of the Veress needle. The system includes a modified Veress needle which containes an optical bundle, a light spectrum analyzing and control unit. Therefore, the tissue reflective spectrum can be vivid observed and analyzed through the fiber optical technology during the procedure of the Veress needle insertion. In this study, we have measured the reflective spectra of various porcine abdominal tissues. The features of their spectra were analyzed and characterized to build up the data base and create an algorithm for tissue discrimination in laparoscopy. The results showed that the correlation coefficient (r) of the reflective spectrum can be 0.79-0.95 for the wavelength range of 350-1000 nm and 0.85-0.98 for the wavelength range of 350-650 nm in the same tissue of various samples which were obtained from different days. An alternative way for tissue discrimination is achieved through a decision making tree according to the characteristics of tissue spectrum. For single blind test the success rate is nearly 100%. It seems that both the algorithms mentioned above for tissue discrimination are all very promising. Therefore, these algorithms will be applied to in vivo study in animal in the near future.

We report a novel simultaneous fingerprint (FP) and high-wavenumber (HW) fiber-optic Raman spectroscopy developed for in vivo diagnosis of intestinal metaplasia (IM) in the stomach under wide-field endoscopic imaging. The FP/HW Raman endoscopy technique was performed to differentiate IM from normal tissues with sensitivity of 89% and specificity of 83%. This study shows the great potential of the FP/HW Raman endoscopic technique for early diagnosis of non-neoplastic gastric disease in vivo during routine endoscopic examination.

Due to the increasing incidences of malignant melanoma, there is a rising demand for assistive technologies for its early diagnosis and improving the survival rate. The commonly used visual screening method is with limited accuracy as the early phase of melanoma shares many clinical features with an atypical nevus, while conventional dermoscopes are not user-friendly in terms of setup time and operations. Therefore, the development of an intelligent and handy system to assist the accurate screening and long-term monitoring of melanocytic skin lesions is crucial for early diagnosis and prevention of melanoma. In this paper, an advanced design of non-invasive and non-radioactive dermoscopy system was reported. Computer-aided simulations were conducted for optimizing the optical design and uniform illumination distribution. Functional prototype and the software system were further developed, which could enable image capturing at 10x amplified and general modes, convenient data transmission, analysis of dermoscopic features (e.g., asymmetry, border irregularity, color, diameter and dermoscopic structure) for assisting the early detection of melanoma, extract patient information (e.g. code, lesion location) and integrate with dermoscopic images, thus further support long term monitoring of diagnostic analysis results. A clinical trial study was further conducted on 185 Chinese children (0-18 years old). The results showed that for all subjects, skin conditions diagnosed based on the developed system accurately confirmed the diagnoses by conventional clinical procedures. Besides, clinical analysis on dermoscopic features and a potential standard approach by the developed system to support identifying specific melanocytic patterns for dermoscopic examination in Chinese children were also reported.

With early detection, five year survival rates for ovarian cancer are over 90%, yet no effective early screening method exists. Emerging consensus suggests that perhaps over 50% of the most lethal form of the disease, high grade serous ovarian cancer, originates in the Fallopian tube. Cancer changes molecular concentrations of various endogenous fluorophores. Using specific excitation wavelengths and emissions bands on a Multispectral Fluorescence Imaging (MFI) system, spatial and spectral data over a wide field of view can be collected from endogenous fluorophores. Wavelength specific reflectance images provide additional information to normalize for tissue geometry and blood absorption. Ratiometric combination of the images may create high contrast between neighboring normal and abnormal tissue. Twenty-six women undergoing oophorectomy or debulking surgery consented the use of surgical discard tissue samples for MFI imaging. Forty-nine pieces of ovarian tissue and thirty-two pieces of Fallopian tube tissue were collected and imaged with excitation wavelengths between 280 nm and 550 nm. After imaging, each tissue sample was fixed, sectioned and HE stained for pathological evaluation. Comparison of mean intensity values between normal, benign, and cancerous tissue demonstrate a general trend of increased fluorescence of benign tissue and decreased fluorescence of cancerous tissue when compared to normal tissue. The predictive capabilities of the mean intensity measurements are tested using multinomial logistic regression and quadratic discriminant analysis. Adaption of the system for in vivo Fallopian tube and ovary endoscopic imaging is possible and is briefly described.

Excision of the whole tumor is crucial, but remains difficult for many tumor types. Fluorescence lifetime imaging could be helpful intraoperative to differentiate normal from tumor tissue. In this study we investigated the difference in fluorescence lifetime imaging of indocyanine green coupled to cyclic RGD free in solution/serum or bound to integrins e.g. in tumors. The U87-MG glioblastoma cell line, expressing high integrin levels, was cultured to use in vitro and to induce 4 subcutaneous tumors in a-thymic mice (n=4). Lifetimes of bound and unbound probe were measured with an experimental time-domain single-photon avalanche diode array (time resolution <100ps). In vivo measurements were taken 30-60 minutes after intravenous injection, and after 24 hours. The in vitro lifetime of the fluorophores was similar at different concentrations (20, 50 and 100μM) and showed a statistically significant higher lifetime (p<0.001) of bound probe compared to unbound probe. In vivo, lifetimes of the fluorophores in tumors were significantly higher (p<0.001) than at the control site (tail) at 30-60 minutes after probe injection. Lifetimes after 24 hours confirmed tumor-specific binding (also validated by fluorescence intensity images). Based on the difference in lifetime imaging, it can be concluded that it is feasible to separate between bound and unbound probes in vivo.

Minimally invasive surgeries are approaching 50% of all interventional procedures in the US, yet there is a lack of objective tools to assist surgeons in this limited sensing environment. In this preliminary work, we present a novel proof of concept implementation of Single Snapshot of Optical Properties (SSOP) imaging through a rigid endoscope. In this embodiment, a stereo rigid endoscope is used with one channel to project spatially modulated illumination and the second channel to image the diffuse reflectance onto a CCD sensor. Optical property maps are then obtained for various tissue simulating phantoms and validated against standard wide-field spatial frequency domain imaging (SFDI). The implementation of endoscopic SSOP creates potential for practical use of endoscopic tissue constituent quantification. The results show good agreement (within 5%) for endoscopic SSOP versus wide-field SFDI. However, endoscopic SSOP acquisition allows for video-rate imaging, limited only by the exposure time of image capture. These results show promise for an objective endoscopic tissue viability assessment tool being achievable in a clinical setting.

Localisation of the cranium is necessary for accurate stereotactic radiotherapy of malign lesions in the brain. This is achieved by immobilizing the patient's head (typically by using thermoplastic masks, bite blocks or combinations thereof) and x-ray imaging to determine the actual position of the patient with respect to the treatment device. In previous work we have developed a novel method for marker-less and non-invasive tracking of the skull using a combination of laser-based surface triangulation and the analysis of backscattered feature patterns of a tightly collimated NIR laser beam scanned over the patient's forehead. An HDR camera is coupled into the beam path of the laser scanning system to acquire one image per projected laser point. We have demonstrated that this setup is capable of accurately determining the tissue thickness for each triangulation point and consequently allows detecting the surface of the cranial bone with sub-millimetre accuracy. Typical clinical settings (treatment times of 15-90 min) require feature stability over time, since the determination of tissue thickness is achieved by machine learning methods trained on initial feature scans. We have collected initial scans of the forehead as well as long-term backscatter data (20 images per seconds over 30 min) from five subjects and extracted the relevant tissue features from the image streams. Based on the knowledge of the relationship between the tissue feature values and the tissue thickness, the analysis of the long-term data showed that the noise level is low enough to allow robust discrimination of tissue thicknesses of 0.5 mm.

Long period fiber gratings (LPGs) have recently been proposed as label-free biosensors. A biochemical interaction occurring along the grating region can be evaluated as a refractive index (RI) change, which modifies the transmission spectrum of the fiber. This is an emergent, alternative choice with respect to other label-free optical systems, such as surface plasmon resonance, interferometric and in-fiber configurations, and resonating structures. In this work, various types of not-coated LPGs, in which the coupling occurs with increasing cladding mode orders, were manufactured for increasing the RI sensitivity of these sensors. After the functionalization of the fiber surface using Eudragit L100 copolymer, a label-free IgG/anti-IgG bioassay was realized for analyzing the antigen/antibody interaction following the same model assay. A comprehensive feasibility study was carried out among the different LPGs in order to assess and compare the biosensor performance, highlighting the advantages and the disadvantages of each type. Experimental results proved an improvement in the RI sensitivity and in the biosensor performance in the case of high-order cladding mode LPGs, with values of detection limit lower than 50 ng mL^-1 (330 pM). The performance enhancement can be explained with the increase in the penetration depth of the evanescent field due to the increase of the cladding mode order. The sensor response was also studied using complex matrices made up of human serum.

The presented work describes the development and verification of a novel optical, powder-free intra-oral scanner based on chromatic confocal technology combined with a multifocal approach. The proof of concept for a chromatic confocal area scanner for intra-oral scanning is given. Several prototype scanners passed a verification process showing an average accuracy (distance deviation on flat surfaces) of less than 31μm ± 21μm and a reproducibility of less than 4μm ± 3μm. Compared to a tactile measurement on a full jaw model fitted with 4mm ceramic spheres the measured average distance deviation between the spheres was 49μm ± 12μm for scans of up to 8 teeth (3- unit bridge, single Quadrant) and 104μm ± 82μm for larger scans and full jaws. The average deviation of the measured sphere diameter compared to the tactile measurement was 27μm ± 14μm. Compared to μCT scans of plaster models equipped with human teeth the average standard deviation on up to 3 units was less than 55μm ± 49μm whereas the reproducibility of the scans was better than 22μm ± 10μm.

Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory protein present in blood and a marker of disease presence, severity and prognosis. A heterogeneous sandwich assay is proposed for quantifying suPAR by employing a capture antibody from rat and a biotinylated detection antibody from mouse. Optical detection was achieved by a successive exposure of the biotinylated sandwich to streptavidin labelled with ATTO647N. The heterogeneous assay was implemented on a multichannel polymethylmetacrylate (PMMA) optical biochip, potentially capable of the simultaneous detection of more than one analyte. Capture antibody was immobilized on the PMMA surface of the microfluidic channel and the assay was performed with the following protocol: i) surface blocking with BSA, ii) incubation with suPAR or PBS, iii) incubation with biotinylated suPAR detection Ab and iv) incubation with streptavidin-ATTO647N. Promising preliminary results were obtained with this protocol. Moreover, an improved optical setup is proposed which avoids the mechanical scanning of the chip and consequently the in-series fluorescence excitation and read out, allowing the simultaneous measurement of the fluorescence on all the channels of the microfluidic chip.

Fusion of video and other imaging modalities is common in modern surgical scenarios to provide surgeons with additional information. Doing so requires the use of interventional guidance equipment and surgical navigation systems to register the tools and devices used in surgery with each other. In this work, we focus explicitly on registering ultrasound with a stereocamera system using photoacoustic markers. Previous work has shown that photoacoustic markers can be used to register three-dimensional ultrasound with video resulting in target registration errors lower than the current available systems. Photoacoustic markers are non-collinear laser spots projected onto some surface. They can be simultaneously visualized by a stereocamera system and in an ultra-sound volume because of the photoacoustic effect. This work replaces the three-dimensional ultrasound volume with images from a single ultrasound image pose. While an ultrasound volume provides more information than an ultrasound image, it has its disadvantages such as higher cost and slower acquisition rate. However, in general, it is difficult to register two-dimensional with three-dimensional spatial data. We propose the use of photoacoustic markers viewed by a convex array ultrasound transducer. Each photoacoustic markers wavefront provides information on its elevational position, resulting in three-dimensional spatial data. This development enhances this methods practicality as convex array transducers are more common in surgical practice than three-dimensional transducers. This work is demonstrated on a synthetic phantom. The resulting target registration error for this experiment was 2.47mm and the standard deviations was 1.29mm, which is comparable to current available systems.

The application of shifted excitation Raman difference spectroscopy (SERDS) using a dual wavelength distributed Bragg reflector (DBR) diode laser at 785 nm will be presented. Both excitation wavelengths necessary for SERDS provide an optical power of more than 160 mW in continuous wave operation. Raman experiments are carried out and demonstrate the suitability of the excitation light source for SERDS. Moreover, a dual-wavelength master-oscillator power amplifier diode laser system is presented. The diode laser system reaches optical powers larger 750 mW while the spectral properties of the dual-wavelength laser remain unchanged.

The combination of near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS) offers the ability to provide real-time monitoring of cerebral oxygenation, blood flow and oxygen consumption. However, measuring these parameters accurately requires depth-sensitive techniques that can remove the effects of signal contamination from extracerebral tissues. Towards this goal, we developed and characterized a hybrid DCS/time-resolved (TR)-NIRS system. Both systems acquire data at three source-detector distances (SDD: 7, 20 and 30 mm) to provide depth sensitivity. The TR-NIRS system uses three pulsed lasers (760, 810, and 830 nm) to quantify tissue optical properties, and DCS uses one continuous-wave, long coherence length (>5 m) laser (785 nm) for blood flow monitoring. The stability of the TR-NIRS system was characterized by continuously measuring the instrument response function (IRF) for four hours, and a warmup period of two hours was required to reduce the coefficient of variation of the extracted optical properties to < 2%. The errors in the measured optical properties were <10% at SDDs of 20 and 30 mm; however, the error at 7 mm was greater due to the effects of the IRF. The number of DCS detectors at each SDD and the minimum count-rate (20 kHz per detector resulting in <10% uncertainty in the extracted blood flow index) were optimized using a homogenous phantom. The depth sensitivity was assessed using a two-layer phantom, with the flow rate in the bottom layer altered to mimic cerebral blood flow.

Dynamic optical tomographic imaging has shown promise in diagnosing and monitoring peripheral arterial disease (PAD), which affects 8 to 12 million in the United States. PAD is the narrowing of the arteries that supply blood to the lower extremities. Prolonged reduced blood flow to the foot leads to ulcers and gangrene, which makes placement of optical fibers for contact-based optical tomography systems difficult and cumbersome. Since many diabetic PAD patients have foot wounds, a non-contact interface is highly desirable. We present a novel non-contact dynamic continuous-wave optical tomographic imaging system that images the vasculature in the foot for evaluating PAD. The system images at up to 1Hz by delivering 2 wavelengths of light to the top of the foot at up to 20 source positions through collimated source fibers. Transmitted light is collected with an electron multiplying charge couple device (EMCCD) camera. We demonstrate that the system can resolve absorbers at various locations in a phantom study and show the system’s first clinical 3D images of total hemoglobin changes in the foot during venous occlusion at the thigh. Our initial results indicate that this system is effective in capturing the vascular dynamics within the foot and can be used to diagnose and monitor treatment of PAD in diabetic patients.

By using a “slit-less” Fourier-transform spectrometer, we demonstrate that cardiac-pulsation amplitude of absorbance can be extracted from 3.5-level absorbance unit (AU) spectra of a human fingertip with a resolution of < 0.0005 AU and a spectral resolution of < several tens of nanometers, even with a low-cost “non-cooled” NIR detector. From the extracted spectrum over 1,000-1,400 nm, the average amounts of pulsating blood components (water, HbO₂, and lipids/proteins) in a fingertip are deduced in the sub-milligram order. The results indicate the capacity of the spectrometer for a portable non-invasive blood monitor as well as for a high-end analytic instrument.

Wide-field oxygenation saturation (StO2) estimates can be clinically very advantageous. Particularly when implemented in a non-contact manner, applications such as intra-operative assessment of tissue perfusion are very promising. Nevertheless, wide-field optical oxygenation imaging did not yet successfully translate to the clinic.

In this work we compare four proposed methods for wide-field imaging that are based on different photon propagation models and that depend on different sets of assumed parameters such as absorption and reduced scattering coefficients. We investigated these for methods, with particular attention to sensitivities to errors in assumed parameters of calibration estimates. To this end we acquired an in vivo time series of a pig skin flap with a venous occlusion. StO2 estimates of all methods were compared to estimates from spatial frequency domain imaging of the same time series.

Correct assumptions on scatter power and accurate calibration were found to be the most important prerequisites for accurate StO2 estimates. Although all models were able to measure relative changes in StO2 when the occlusion was applied and released, only the models that incorporated assumed reduced scattering coefficients estimated StO2 values within 5% of the expected values (estimated using SFDI).

An important aspect of the compared methods is their ability to be used for real-time imaging. With the addition of real-time calibration and robust tissue scattering estimates, real-time wide-field imaging of oxygenation saturation can prove to provide important added value in the clinic.

Thrombosis became one of the most severe disease hazard to human health, and it incidence rate grows increasingly higher throughout the world. The conventional diagnosis and monitoring thrombosis mainly relied on the invasive techniques, e.g., digital subtraction angiography and blood sample analysis, and expensive and ionizing techniques, e.g., magnetic resonance angiography. And those techniques can not measure continuously. Here we reported our preliminary exploration of using near-infrared spectroscopy (NIRS) in clinical monitoring of thrombosis. 7 healthy subjects and 6 thrombosis patients at similar age participated the NIRS measurements of oxy- and deoxy- hemoglobin ([HbO2] and [Hb]) on 6 particular parts of legs. We repeated [HbO2] measurement at the same specified time each day after thrombolytic therapy for one single-leg-DVT patient, and terminated till the patient was cured and left hospital. We found that：(1) [HbO2] kept lower in thrombosis patients and [Hb] kept lower in healthy people (p<0.001); (2) [HbO2] kept increasing in the thrombosis leg but decreasing in healthy leg for the patients after thrombolytic therapy, and coincidently, [HbO2] acted consistent just when the patients were cured and left. Our study successfully extended the application of NIRS in noninvasive, continuous, and low-cost monitoring of thrombosis in clinics. Our findings showed the powerful potential of [HbO2] by NIRS in diagnosis and therapeutic effect evaluation of thrombosis.

Indocyanine green (ICG), a near-infrared fluorophore, has been used in visualization of vascular structure and non-invasive diagnosis of vascular disease. Although many imaging techniques have been developed, there are still limitations in diagnosis of vascular diseases. We have recently developed a minimally invasive diagnostics system based on ICG fluorescence imaging for sensitive detection of vascular insufficiency. In this study, we used principal component analysis (PCA) to examine ICG spatiotemporal profile and to obtain pathophysiological information from ICG dynamics. Here we demonstrated that principal components of ICG dynamics in both feet showed significant differences between normal control and diabetic patients with vascula complications. We extracted the PCA time courses of the first three components and found distinct pattern in diabetic patient. We propose that PCA of ICG dynamics reveal better classification performance compared to fluorescence intensity analysis. We anticipate that specific feature of spatiotemporal ICG dynamics can be useful in diagnosis of various vascular diseases.

We propose a quantitative evaluation method of skin barrier function using Optical Coherence Microscopy system (OCM system) with coherency of near-infrared light. There are a lot of skin problems such as itching, irritation and so on. It has been recognized skin problems are caused by impairment of skin barrier function, which prevents damage from various external stimuli and loss of water. To evaluate skin barrier function, it is a common strategy that they observe skin surface and ask patients about their skin condition. The methods are subjective judgements and they are influenced by difference of experience of persons. Furthermore, microscopy has been used to observe inner structure of the skin in detail, and in vitro measurements like microscopy requires tissue sampling. On the other hand, it is necessary to assess objectively skin barrier function by quantitative evaluation method. In addition, non-invasive and nondestructive measuring method and examination changes over time are needed. Therefore, in vivo measurements are crucial for evaluating skin barrier function. In this study, we evaluate changes of stratum corneum structure which is important for evaluating skin barrier function by comparing water-penetrated skin with normal skin using a system with coherency of near-infrared light. Proposed method can obtain in vivo 3D images of inner structure of body tissue, which is non-invasive and non-destructive measuring method. We formulate changes of skin ultrastructure after water penetration. Finally, we evaluate the limit of performance of the OCM system in this work in order to discuss how to improve the OCM system.

Tissues are an impressive complex creation comprised of a vast of assortment of molecules, structures and functional units. Despite this overwhelming complexity, we may still discuss average optical properties as long as we realize the limitations involved. There are five independent macroscopic parameters that are believed to characterize light propagation in tissue: the index of refraction (n), the absorption coefficient (μa), the scattering coefficient (μ_s), the reduced scattering coefficient (μ's), and the scattering anisotropy (g). This paper summarizes the Optical characteristics of tissue of prostate tissues ex vivo and the key fluorophores related to carcinogenesis. The absorption coefficient (μa) describes the effectiveness of light absorbed by certain chromophore. The key spectra fingerprints of water were introduced to distinguish different water contents in normal and cancerous prostate tissues. Fluorescence occurs when a molecule, atom or nanostructure relaxes to its ground state after being electrically excited. There are three fluorescence parameters of interest we may concern in tissue optics: the fluorescence lifetime (τ_f), the fluorescence quantum yield (Φ) and the fluorescence emission peak (λ_max). The key wavelengths which can be used for cancer detection were reviewed. Scattering of light occurs in media which contains fluctuations in the refractive index n. Tissue ultrastructure extends from membranes to membrane aggregates to collagen fibers to nuclei to cells, which may be an alternative way to detect cancer in tissues.

We propose an intestine volume measurement method using a compound eye type endoscope. This method aims at assessment of the gastrointestinal function. Gastrointestinal diseases are mainly based on morphological abnormalities. However, gastrointestinal symptoms are sometimes apparent without visible abnormalities. Such diseases are called functional gastrointestinal disorder, for example, functional dyspepsia, and irritable bowel syndrome. One of the major factors for these diseases is abnormal gastrointestinal motility. For the diagnosis of the gastrointestinal tract, both aspects of organic and functional assessment is important. While endoscopic diagnosis is essential for assessment of organic abnormalities, three-dimensional information is required for assessment of the functional abnormalities. Thus, we proposed the three dimensional endoscope system using compound eye. In this study, we forces on the volume of gastrointestinal tract. The volume of the gastrointestinal tract is thought to related its function. In our system, we use a compound eye type endoscope system to obtain three-dimensional information of the tract. The volume can be calculated by integrating the slice data of the intestine tract shape using the obtained three-dimensional information. First, we evaluate the proposed method by known-shape tube. Then, we confirm that the proposed method can measure the tract volume using the tract simulated model. Our system can assess the wall of gastrointestinal tract directly in a three-dimensional manner. Our system can be used for examination of gastric morphological and functional abnormalities.