Imaging subsurface geology and volatile organic compound plumes

International Nuclear Information System (INIS)

Qualheim, B.J.; Daley, P.F.; Johnson, V.; McPherrin, R.V.; Laguna, G.

1992-03-01

Lawrence Livermore National Laboratory (LLNL) (Fig. 1) is in the final stages of the Superfund decisionmaking process for site remediation and restoration. In the process of characterizing the subsurface of the LLNL site, we have developed unique methods of collecting, storing, retrieving, and imaging geologic and chemical data from more than 350 drill holes. The lateral and vertical continuity of subsurface paleostream channels were mapped for the entire LLNL site using geologic descriptions from core samples, cuttings, and interpretations from geophysical logs. A computer-aided design and drafting program, SLICE, written at LLNL, was used to create two-dimensional maps of subsurface sediments, and state-of-the-art software produced three-dimensional images of the volatile organic compound (VOC) plumes using data from water and core fluid analyses

The feasibility of endoscopy-CT image registration in the head and neck without prospective endoscope tracking.

Directory of Open Access Journals (Sweden)

W Scott Ingram

Full Text Available Endoscopic examinations are frequently-used procedures for patients with head and neck cancer undergoing radiotherapy, but radiation treatment plans are created on computed tomography (CT scans. Image registration between endoscopic video and CT could be used to improve treatment planning and analysis of radiation-related normal tissue toxicity. The purpose of this study was to explore the feasibility of endoscopy-CT image registration without prospective physical tracking of the endoscope during the examination.A novel registration technique called Location Search was developed. This technique uses physical constraints on the endoscope's view direction to search for the virtual endoscope coordinates that maximize the similarity between the endoscopic video frame and the virtual endoscopic image. Its performance was tested on phantom and patient images and compared to an established registration technique, Frame-To-Frame Tracking.In phantoms, Location Search had average registration errors of 0.55 ± 0.60 cm for point measurements and 0.29 ± 0.15 cm for object surface measurements. Frame-To-Frame Tracking achieved similar results on some frames, but it failed on others due to the virtual endoscope becoming lost. This weakness was more pronounced in patients, where Frame-To-Frame tracking could not make it through the nasal cavity. On successful patient video frames, Location Search was able to find endoscope positions with an average distance of 0.98 ± 0.53 cm away from the ground truth positions. However, it failed on many frames due to false similarity matches caused by anatomical structural differences between the endoscopic video and the virtual endoscopic images.Endoscopy-CT image registration without prospective physical tracking of the endoscope is possible, but more development is required to achieve an accuracy suitable for clinical translation.

[Digital imaging and robotics in endoscopic surgery].

Science.gov (United States)

Go, P M

1998-05-23

The introduction of endoscopical surgery has among other things influenced technical developments in surgery. Owing to digitalisation, major progress will be made in imaging and in the sophisticated technology sometimes called robotics. Digital storage makes the results of imaging diagnostics (e.g. the results of radiological examination) suitable for transmission via video conference systems for telediagnostic purposes. The availability of digital video technique renders possible the processing, storage and retrieval of moving images as well. During endoscopical operations use may be made of a robot arm which replaces the camera man. The arm does not grow tired and provides a stable image. The surgeon himself can operate or address the arm and it can remember fixed image positions to which it can return if ordered to do so. The next step is to carry out surgical manipulations via a robot arm. This may make operations more patient-friendly. A robot arm can also have remote control: telerobotics. At the Internet site of this journal a number of supplements to this article can be found, for instance three-dimensional (3D) illustrations (which is the purpose of the 3D spectacles enclosed with this issue) and a quiz (http:@appendix.niwi. knaw.nl).

Development of an integrated filing system for endoscopic images.

Science.gov (United States)

Fujino, M A; Ikeda, M; Yamamoto, Y; Kinose, T; Tachikawa, H; Morozumi, A; Sano, S; Kojima, Y; Nakamura, T; Kawai, T

1991-01-01

A new integrated filing system for endoscopic images has been developed, comprising a main image filing system and subsystems located at different stations. A hybrid filing system made up of both digital and analog filing devices was introduced to construct this system that combines the merits of the two filing methods. Each subsystem provided with a video processor, is equipped with a digital filing device, and routine images were recorded in the analog image filing device of the main system. The use of a multi-input adapter enabled simultaneous input of analog images from up to 8 video processors. Recorded magneto-optical disks make it possible to recall the digital images at any station in the hospital; the disks are copied without image degradation and also utilised for image processing. This system promises reliable storage and integrated, efficient management of endoscopic information. It also costs less to install than the so-called PACS (picture archiving and communication system), which connects all the stations of the hospital using optical fiber cables.

Image-based overlay measurement using subsurface ultrasonic resonance force microscopy

Science.gov (United States)

Tamer, M. S.; van der Lans, M. J.; Sadeghian, H.

2018-03-01

Image Based Overlay (IBO) measurement is one of the most common techniques used in Integrated Circuit (IC) manufacturing to extract the overlay error values. The overlay error is measured using dedicated overlay targets which are optimized to increase the accuracy and the resolution, but these features are much larger than the IC feature size. IBO measurements are realized on the dedicated targets instead of product features, because the current overlay metrology solutions, mainly based on optics, cannot provide sufficient resolution on product features. However, considering the fact that the overlay error tolerance is approaching 2 nm, the overlay error measurement on product features becomes a need for the industry. For sub-nanometer resolution metrology, Scanning Probe Microscopy (SPM) is widely used, though at the cost of very low throughput. The semiconductor industry is interested in non-destructive imaging of buried structures under one or more layers for the application of overlay and wafer alignment, specifically through optically opaque media. Recently an SPM technique has been developed for imaging subsurface features which can be potentially considered as a solution for overlay metrology. In this paper we present the use of Subsurface Ultrasonic Resonance Force Microscopy (SSURFM) used for IBO measurement. We used SSURFM for imaging the most commonly used overlay targets on a silicon substrate and photoresist. As a proof of concept we have imaged surface and subsurface structures simultaneously. The surface and subsurface features of the overlay targets are fabricated with programmed overlay errors of +/-40 nm, +/-20 nm, and 0 nm. The top layer thickness changes between 30 nm and 80 nm. Using SSURFM the surface and subsurface features were successfully imaged and the overlay errors were extracted, via a rudimentary image processing algorithm. The measurement results are in agreement with the nominal values of the programmed overlay errors.

Computer-based endoscopic image-processing technology for endourology and laparoscopic surgery

International Nuclear Information System (INIS)

Igarashi, Tatsuo; Suzuki, Hiroyoshi; Naya, Yukio

2009-01-01

Endourology and laparoscopic surgery are evolving in accordance with developments in instrumentation and progress in surgical technique. Recent advances in computer and image-processing technology have enabled novel images to be created from conventional endoscopic and laparoscopic video images. Such technology harbors the potential to advance endourology and laparoscopic surgery by adding new value and function to the endoscope. The panoramic and three-dimensional images created by computer processing are two outstanding features that can address the shortcomings of conventional endoscopy and laparoscopy, such as narrow field of view, lack of depth cue, and discontinuous information. The wide panoramic images show an anatomical map' of the abdominal cavity and hollow organs with high brightness and resolution, as the images are collected from video images taken in a close-up manner. To assist in laparoscopic surgery, especially in suturing, a three-dimensional movie can be obtained by enhancing movement parallax using a conventional monocular laparoscope. In tubular organs such as the prostatic urethra, reconstruction of three-dimensional structure can be achieved, implying the possibility of a liquid dynamic model for assessing local urethral resistance in urination. Computer-based processing of endoscopic images will establish new tools for endourology and laparoscopic surgery in the near future. (author)

Subsurface Profile Mapping using 3-D Compressive Wave Imaging

Directory of Open Access Journals (Sweden)

Hazreek Z A M

2017-01-01

Full Text Available Geotechnical site investigation related to subsurface profile mapping was commonly performed to provide valuable data for design and construction stage based on conventional drilling techniques. From past experience, drilling techniques particularly using borehole method suffer from limitations related to expensive, time consuming and limited data coverage. Hence, this study performs subsurface profile mapping using 3-D compressive wave imaging in order to minimize those conventional method constraints. Field measurement and data analysis of compressive wave (p-wave, vp was performed using seismic refraction survey (ABEM Terraloc MK 8, 7 kg of sledgehammer and 24 units of vertical geophone and OPTIM (SeisOpt@Picker & SeisOpt@2D software respectively. Then, 3-D compressive wave distribution of subsurface studied was obtained using analysis of SURFER software. Based on 3-D compressive wave image analyzed, it was found that subsurface profile studied consist of three main layers representing top soil (vp = 376 – 600 m/s, weathered material (vp = 900 – 2600 m/s and bedrock (vp > 3000 m/s. Thickness of each layer was varied from 0 – 2 m (first layer, 2 – 20 m (second layer and 20 m and over (third layer. Moreover, groundwater (vp = 1400 – 1600 m/s starts to be detected at 2.0 m depth from ground surface. This study has demonstrated that geotechnical site investigation data related to subsurface profiling was applicable to be obtained using 3-D compressive wave imaging. Furthermore, 3-D compressive wave imaging was performed based on non destructive principle in ground exploration thus consider economic, less time, large data coverage and sustainable to our environment.

Emphysema. Imaging for endoscopic lung volume reduction

International Nuclear Information System (INIS)

Storbeck, B.; Oldigs, M.; Rabe, K.F.; Weber, C.; University Medical Center Hamburg-Eppendorf

2015-01-01

Chronic obstructive pulmonary disease (COPD) is characterized by two entities, the more airway-predominant type (''bronchitis'') on the one hand, and emphysema-predominant type on the other. Imaging via high-resolution computed tomography plays an important role in phenotyping COPD. For patients with advanced lung emphysema, new endoscopic lung volume reduction therapies (ELVR) have been developed. Proper selection of suitable patients requires thin-section reconstruction of volumetric CT image data sets also in coronal and sagittal orientation are required. In the current manuscript we will describe emphysema subtypes (centrilobular, paraseptal, panlobular), options for quantifying emphysema and this importance of regional distribution (homogeneous or heterogeneous, target area) as this is crucial for patient selection. Analysis of the interlobular fissures is obligatory despite the lack of standardization, as incomplete fissures indicate collateral ventilation (CV) via parenchymal bridges, which is an important criterion in choosing endoscopic methods of LVR. Every radiologist should be familiar with modern LVR therapies such as valves and coils, and furthermore should know what a lung doctor expects from radiologic evaluation (before and after ELVR). Finally we present a checklist as a quick reference for all steps concerning imaging for ELVR.

Image-based navigation for a robotized flexible endoscope

NARCIS (Netherlands)

van der Stap, N.; Slump, Cornelis H.; Broeders, Ivo Adriaan Maria Johannes; van der Heijden, Ferdinand; Luo, Xiongbiao; Reichl, Tobias; Mirota, Daniel; Soper, Timothy

2014-01-01

Robotizing flexible endoscopy enables image-based control of endoscopes. Especially during high-throughput procedures, such as a colonoscopy, navigation support algorithms could improve procedure turnaround and ergonomics for the endoscopist. In this study, we have developed and implemented a

Imaging of common bile duct by linear endoscopic ultrasound

Institute of Scientific and Technical Information of China (English)

Malay; Sharma; Amit; Pathak; Abid; Shoukat; Chittapuram; Srinivasan; Rameshbabu; Akash; Ajmera; Zeeshn; Ahamad; Wani; Praveer; Rai

2015-01-01

Imaging of common bile duct(CBD) can be done by many techniques. Endoscopic retrograde cholangiopancreaticography is considered the gold standard for imaging of CBD. A standard technique of imaging of CBD by endoscopic ultrasound(EUS) has not been specifically described. The available descriptions mention different stations of imaging from the stomach and duodenum. The CBD lies closest to duodenum and choice of imaging may be restricted to duodenum for many operators. Generally most operators prefer multi station imaging during EUS and the choice of selecting the initial station varies from operator to operator. Detailed evaluation of CBD is frequently the main focus of imaging during EUS and in such situations multi station imaging with a high-resolution ultrasound scanner may provide useful information. Examination of the CBD is one of the primary indications for doing an EUS and it can be done from five stations:(1) the fundus of stomach;(2) body of stomach;(3) duodenal bulb;(4) descending duodenum; and(5) antrum. Following down the upper 1/3rd of CBD can do imaging of entire CBD from the liver window and following up the lower 1/3rd of CBD can do imaging of entire CBD from the pancreatic window. This article aims at simplifying the techniques of imaging of CBD by linear EUS.

Neuro-fuzzy Classification System for Wireless-Capsule Endoscopic Images

OpenAIRE

Vassilis S. Kodogiannis; John N. Lygouras

2008-01-01

In this research study, an intelligent detection system to support medical diagnosis and detection of abnormal lesions by processing endoscopic images is presented. The images used in this study have been obtained using the M2A Swallowable Imaging Capsule - a patented, video color-imaging disposable capsule. Schemes have been developed to extract texture features from the fuzzy texture spectra in the chromatic and achromatic domains for a selected region of interest from ...

Endoscopic device for functional imaging of the retina

Science.gov (United States)

Barriga, Simon; Lohani, Sweyta; Martell, Bret; Soliz, Peter; Ts'o, Dan

2011-03-01

Non-invasive imaging of retinal function based on the recording of spatially distributed reflectance changes evoked by visual stimuli has to-date been performed primarily using modified commercial fundus cameras. We have constructed a prototype retinal functional imager, using a commercial endoscope (Storz) for the frontend optics, and a low-cost back-end that includes the needed dichroic beam splitter to separate the stimulus path from the imaging path. This device has been tested to demonstrate its performance for the delivery of adequate near infrared (NIR) illumination, intensity of the visual stimulus and reflectance return in the imaging path. The current device was found to be capable of imaging reflectance changes of 0.1%, similar to that observable using the modified commercial fundus camera approach. The visual stimulus (a 505nm spot of 0.5secs) was used with an interrogation illumination of 780nm, and a sequence of imaged captured. At each pixel, the imaged signal was subtracted and normalized by the baseline reflectance, so that the measurement was ΔR/R. The typical retinal activity signal observed had a ΔR/R of 0.3-1.0%. The noise levels were measured when no stimulus was applied and found to vary between +/- 0.05%. Functional imaging has been suggested as a means to provide objective information on retina function that may be a preclinical indicator of ocular diseases, such as age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy. The endoscopic approach promises to yield a significantly more economical retinal functional imaging device that would be clinically important.

4-mm-diameter three-dimensional imaging endoscope with steerable camera for minimally invasive surgery (3-D-MARVEL).

Science.gov (United States)

Bae, Sam Y; Korniski, Ronald J; Shearn, Michael; Manohara, Harish M; Shahinian, Hrayr

2017-01-01

High-resolution three-dimensional (3-D) imaging (stereo imaging) by endoscopes in minimally invasive surgery, especially in space-constrained applications such as brain surgery, is one of the most desired capabilities. Such capability exists at larger than 4-mm overall diameters. We report the development of a stereo imaging endoscope of 4-mm maximum diameter, called Multiangle, Rear-Viewing Endoscopic Tool (MARVEL) that uses a single-lens system with complementary multibandpass filter (CMBF) technology to achieve 3-D imaging. In addition, the system is endowed with the capability to pan from side-to-side over an angle of [Formula: see text], which is another unique aspect of MARVEL for such a class of endoscopes. The design and construction of a single-lens, CMBF aperture camera with integrated illumination to generate 3-D images, and the actuation mechanism built into it is summarized.

Assessment of colonoscopy by use of magnetic endoscopic imaging

DEFF Research Database (Denmark)

Nerup, Nikolaj; Preisler, Louise; Svendsen, Morten Bo Søndergaard

2015-01-01

and a difficult case. SETTING: Center for Clinical Education, Capital Region of Denmark. MAIN OUTCOME MEASUREMENTS: By using magnetic endoscopic imaging, we developed a colonoscopy progression score (CoPS). A pass/fail score was established by using the contrast-group method. RESULTS: We found significant...... differences in performance between the 2 groups using the CoPS in both case scenarios (easy: P heterogeneity of the experienced group resulted in a high passing score for the difficult case, which led to the failing of the less experienced...... in the group. The CoPS does not consider polyp detection rate, tissue damage, or patient discomfort. CONCLUSIONS: We developed a score of progression in colonoscopy, based on magnetic endoscopic imaging. With the same tool, a map of progression in colonoscopy can be provided. The CoPS and map of progression...

Quantitative sub-surface and non-contact imaging using scanning microwave microscopy

International Nuclear Information System (INIS)

Gramse, Georg; Kasper, Manuel; Hinterdorfer, Peter; Brinciotti, Enrico; Rankl, Christian; Kienberger, Ferry; Lucibello, Andrea; Marcelli, Romolo; Patil, Samadhan B.; Giridharagopal, Rajiv

2015-01-01

The capability of scanning microwave microscopy for calibrated sub-surface and non-contact capacitance imaging of silicon (Si) samples is quantitatively studied at broadband frequencies ranging from 1 to 20 GHz. Calibrated capacitance images of flat Si test samples with varying dopant density (10 15 –10 19 atoms cm −3 ) and covered with dielectric thin films of SiO 2 (100–400 nm thickness) are measured to demonstrate the sensitivity of scanning microwave microscopy (SMM) for sub-surface imaging. Using standard SMM imaging conditions the dopant areas could still be sensed under a 400 nm thick oxide layer. Non-contact SMM imaging in lift-mode and constant height mode is quantitatively demonstrated on a 50 nm thick SiO 2 test pad. The differences between non-contact and contact mode capacitances are studied with respect to the main parameters influencing the imaging contrast, namely the probe tip diameter and the tip–sample distance. Finite element modelling was used to further analyse the influence of the tip radius and the tip–sample distance on the SMM sensitivity. The understanding of how the two key parameters determine the SMM sensitivity and quantitative capacitances represents an important step towards its routine application for non-contact and sub-surface imaging. (paper)

Kinematics of reflections in subsurface offset and angle-domain image gathers

Science.gov (United States)

Dafni, Raanan; Symes, William W.

2018-05-01

Seismic migration in the angle-domain generates multiple images of the earth's interior in which reflection takes place at different scattering-angles. Mechanically, the angle-dependent reflection is restricted to happen instantaneously and at a fixed point in space: Incident wave hits a discontinuity in the subsurface media and instantly generates a scattered wave at the same common point of interaction. Alternatively, the angle-domain image may be associated with space-shift (regarded as subsurface offset) extended migration that artificially splits the reflection geometry. Meaning that, incident and scattered waves interact at some offset distance. The geometric differences between the two approaches amount to a contradictory angle-domain behaviour, and unlike kinematic description. We present a phase space depiction of migration methods extended by the peculiar subsurface offset split and stress its profound dissimilarity. In spite of being in radical contradiction with the general physics, the subsurface offset reveals a link to some valuable angle-domain quantities, via post-migration transformations. The angle quantities are indicated by the direction normal to the subsurface offset extended image. They specifically define the local dip and scattering angles if the velocity at the split reflection coordinates is the same for incident and scattered wave pairs. Otherwise, the reflector normal is not a bisector of the opening angle, but of the corresponding slowness vectors. This evidence, together with the distinguished geometry configuration, fundamentally differentiates the angle-domain decomposition based on the subsurface offset split from the conventional decomposition at a common reflection point. An asymptotic simulation of angle-domain moveout curves in layered media exposes the notion of split versus common reflection point geometry. Traveltime inversion methods that involve the subsurface offset extended migration must accommodate the split geometry

A deep learning approach for detecting and correcting highlights in endoscopic images

NARCIS (Netherlands)

Rodriguez-Sanchez, Antonio; Chea, Daly; Azzopardi, George; Stabinger, Sebastian

2017-01-01

The image of an object changes dramatically depending on the lightning conditions surrounding that object. Shadows, reflections and highlights can make the object very difficult to be recognized for an automatic system. Additionally, images used in medical applications, such as endoscopic images and

Subsurface offset behaviour in velocity analysis with extended reflectivity images

NARCIS (Netherlands)

Mulder, W.A.

2013-01-01

Migration velocity analysis with the constant-density acoustic wave equation can be accomplished by the focusing of extended migration images, obtained by introducing a subsurface shift in the imaging condition. A reflector in a wrong velocity model will show up as a curve in the extended image. In

Averaged subtracted polarization imaging for endoscopic diagnostics of surface microstructures on translucent mucosae

Science.gov (United States)

Kanamori, Katsuhiro

2016-07-01

An endoscopic image processing technique for enhancing the appearance of microstructures on translucent mucosae is described. This technique employs two pairs of co- and cross-polarization images under two different linearly polarized lights, from which the averaged subtracted polarization image (AVSPI) is calculated. Experiments were then conducted using an acrylic phantom and excised porcine stomach tissue using a manual experimental setup with ring-type lighting, two rotating polarizers, and a color camera; better results were achieved with the proposed method than with conventional color intensity image processing. An objective evaluation method that uses texture analysis was developed and used to evaluate the enhanced microstructure images. This paper introduces two types of online, rigid-type, polarimetric endoscopic implementations using a polarized ring-shaped LED and a polarimetric camera. The first type uses a beam-splitter-type color polarimetric camera, and the second uses a single-chip monochrome polarimetric camera. Microstructures on the mucosa surface were enhanced robustly with these online endoscopes regardless of the difference in the extinction ratio of each device. These results show that polarimetric endoscopy using AVSPI is both effective and practical for hardware implementation.

Automatic specular reflections removal for endoscopic images

Science.gov (United States)

Tan, Ke; Wang, Bin; Gao, Yuan

2017-07-01

Endoscopy imaging is utilized to provide a realistic view about the surfaces of organs inside the human body. Owing to the damp internal environment, these surfaces usually have a glossy appearance showing specular reflections. For many computer vision algorithms, the highlights created by specular reflections may become a significant source of error. In this paper, we present a novel method for restoration of the specular reflection regions from a single image. Specular restoration process starts with generating a substitute specular-free image with RPCA method. Then the specular removed image was obtained by taking the binary weighting template of highlight regions as the weighting for merging the original specular image and the substitute image. The modified template was furthermore discussed for the concealment of artificial effects in the edge of specular regions. Experimental results on the removal of the endoscopic image with specular reflections demonstrate the efficiency of the proposed method comparing to the existing methods.

Using Muons to Image the Subsurface.

Energy Technology Data Exchange (ETDEWEB)

Bonal, Nedra [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cashion, Avery Ted [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cieslewski, Grzegorz [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dorsey, Daniel J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Foris, Adam [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miller, Timothy J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Su, Jiann-Cherng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dreesen, Wendi [NSTec, Livermore, CA (United States); Green, J. Andrew [NSTec, Livermore, CA (United States); Schwellenbach, David [NSTec, Livermore, CA (United States)

2016-11-01

Muons are subatomic particles that can penetrate the earth 's crust several kilometers and may be useful for subsurface characterization . The absorption rate of muons depends on the density of the materials through which they pass. Muons are more sensitive to density variation than other phenomena, including gravity, making them beneficial for subsurface investigation . Measurements of muon flux rate at differing directions provide density variations of the materials between the muon source (cosmic rays and neutrino interactions) and the detector, much like a CAT scan. Currently, muon tomography can resolve features to the sub-meter scale. This work consists of three parts to address the use of muons for subsurface characterization : 1) assess the use of muon scattering for estimating density differences of common rock types, 2 ) using muon flux to detect a void in rock, 3) measure muon direction by designing a new detector. Results from this project lay the groundwork for future directions in this field. Low-density objects can be detected by muons even when enclosed in high-density material like lead, and even small changes in density (e.g. changes due to fracturing of material) can be detected. Rock density has a linear relationship with muon scattering density per rock volume when this ratio is greater than 0.10 . Limitations on using muon scattering to assess density changes among common rock types have been identified. However, other analysis methods may show improved results for these relatively low density materials. Simulations show that muons can be used to image void space (e.g. tunnels) within rock but experimental results have been ambiguous. Improvements are suggested to improve imaging voids such as tunnels through rocks. Finally, a muon detector has been designed and tested to measure muon direction, which will improve signal-to-noise ratio and help address fundamental questions about the source of upgoing muons .

Ultrahigh speed en face OCT capsule for endoscopic imaging.

Science.gov (United States)

Liang, Kaicheng; Traverso, Giovanni; Lee, Hsiang-Chieh; Ahsen, Osman Oguz; Wang, Zhao; Potsaid, Benjamin; Giacomelli, Michael; Jayaraman, Vijaysekhar; Barman, Ross; Cable, Alex; Mashimo, Hiroshi; Langer, Robert; Fujimoto, James G

2015-04-01

Depth resolved and en face OCT visualization in vivo may have important clinical applications in endoscopy. We demonstrate a high speed, two-dimensional (2D) distal scanning capsule with a micromotor for fast rotary scanning and a pneumatic actuator for precision longitudinal scanning. Longitudinal position measurement and image registration were performed by optical tracking of the pneumatic scanner. The 2D scanning device enables high resolution imaging over a small field of view and is suitable for OCT as well as other scanning microscopies. Large field of view imaging for screening or surveillance applications can also be achieved by proximally pulling back or advancing the capsule while scanning the distal high-speed micromotor. Circumferential en face OCT was demonstrated in living swine at 250 Hz frame rate and 1 MHz A-scan rate using a MEMS tunable VCSEL light source at 1300 nm. Cross-sectional and en face OCT views of the upper and lower gastrointestinal tract were generated with precision distal pneumatic longitudinal actuation as well as proximal manual longitudinal actuation. These devices could enable clinical studies either as an adjunct to endoscopy, attached to an endoscope, or as a swallowed tethered capsule for non-endoscopic imaging without sedation. The combination of ultrahigh speed imaging and distal scanning capsule technology could enable both screening and surveillance applications.

WE-AB-BRA-12: Virtual Endoscope Tracking for Endoscopy-CT Image Registration

International Nuclear Information System (INIS)

Ingram, W; Rao, A; Wendt, R; Court, L; Yang, J; Beadle, B

2015-01-01

Purpose: The use of endoscopy in radiotherapy will remain limited until we can register endoscopic video to CT using standard clinical equipment. In this phantom study we tested a registration method using virtual endoscopy to measure CT-space positions from endoscopic video. Methods: Our phantom is a contorted clay cylinder with 2-mm-diameter markers in the luminal surface. These markers are visible on both CT and endoscopic video. Virtual endoscope images were rendered from a polygonal mesh created by segmenting the phantom’s luminal surface on CT. We tested registration accuracy by tracking the endoscope’s 6-degree-of-freedom coordinates frame-to-frame in a video recorded as it moved through the phantom, and using these coordinates to measure CT-space positions of markers visible in the final frame. To track the endoscope we used the Nelder-Mead method to search for coordinates that render the virtual frame most similar to the next recorded frame. We measured the endoscope’s initial-frame coordinates using a set of visible markers, and for image similarity we used a combination of mutual information and gradient alignment. CT-space marker positions were measured by projecting their final-frame pixel addresses through the virtual endoscope to intersect with the mesh. Registration error was quantified as the distance between this intersection and the marker’s manually-selected CT-space position. Results: Tracking succeeded for 6 of 8 videos, for which the mean registration error was 4.8±3.5mm (24 measurements total). The mean error in the axial direction (3.1±3.3mm) was larger than in the sagittal or coronal directions (2.0±2.3mm, 1.7±1.6mm). In the other 2 videos, the virtual endoscope got stuck in a false minimum. Conclusion: Our method can successfully track the position and orientation of an endoscope, and it provides accurate spatial mapping from endoscopic video to CT. This method will serve as a foundation for an endoscopy-CT registration

WE-AB-BRA-12: Virtual Endoscope Tracking for Endoscopy-CT Image Registration

Energy Technology Data Exchange (ETDEWEB)

Ingram, W; Rao, A; Wendt, R; Court, L [The University of Texas MD Anderson Cancer Center, Houston, TX (United States); The University of Texas Graduate School of Biomedical Sciences, Houston, TX (United States); Yang, J; Beadle, B [The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

2015-06-15

Purpose: The use of endoscopy in radiotherapy will remain limited until we can register endoscopic video to CT using standard clinical equipment. In this phantom study we tested a registration method using virtual endoscopy to measure CT-space positions from endoscopic video. Methods: Our phantom is a contorted clay cylinder with 2-mm-diameter markers in the luminal surface. These markers are visible on both CT and endoscopic video. Virtual endoscope images were rendered from a polygonal mesh created by segmenting the phantom’s luminal surface on CT. We tested registration accuracy by tracking the endoscope’s 6-degree-of-freedom coordinates frame-to-frame in a video recorded as it moved through the phantom, and using these coordinates to measure CT-space positions of markers visible in the final frame. To track the endoscope we used the Nelder-Mead method to search for coordinates that render the virtual frame most similar to the next recorded frame. We measured the endoscope’s initial-frame coordinates using a set of visible markers, and for image similarity we used a combination of mutual information and gradient alignment. CT-space marker positions were measured by projecting their final-frame pixel addresses through the virtual endoscope to intersect with the mesh. Registration error was quantified as the distance between this intersection and the marker’s manually-selected CT-space position. Results: Tracking succeeded for 6 of 8 videos, for which the mean registration error was 4.8±3.5mm (24 measurements total). The mean error in the axial direction (3.1±3.3mm) was larger than in the sagittal or coronal directions (2.0±2.3mm, 1.7±1.6mm). In the other 2 videos, the virtual endoscope got stuck in a false minimum. Conclusion: Our method can successfully track the position and orientation of an endoscope, and it provides accurate spatial mapping from endoscopic video to CT. This method will serve as a foundation for an endoscopy-CT registration

Excitation-scanning hyperspectral imaging system for microscopic and endoscopic applications

Science.gov (United States)

Mayes, Sam A.; Leavesley, Silas J.; Rich, Thomas C.

2016-04-01

Current microscopic and endoscopic technologies for cancer screening utilize white-light illumination sources. Hyper-spectral imaging has been shown to improve sensitivity while retaining specificity when compared to white-light imaging in both microscopy and in vivo imaging. However, hyperspectral imaging methods have historically suffered from slow acquisition times due to the narrow bandwidth of spectral filters. Often minutes are required to gather a full image stack. We have developed a novel approach called excitation-scanning hyperspectral imaging that provides 2-3 orders of magnitude increased signal strength. This reduces acquisition times significantly, allowing for live video acquisition. Here, we describe a preliminary prototype excitation-scanning hyperspectral imaging system that can be coupled with endoscopes or microscopes for hyperspectral imaging of tissues and cells. Our system is comprised of three subsystems: illumination, transmission, and imaging. The illumination subsystem employs light-emitting diode arrays to illuminate at different wavelengths. The transmission subsystem utilizes a unique geometry of optics and a liquid light guide. Software controls allow us to interface with and control the subsystems and components. Digital and analog signals are used to coordinate wavelength intensity, cycling and camera triggering. Testing of the system shows it can cycle 16 wavelengths at as fast as 1 ms per cycle. Additionally, more than 18% of the light transmits through the system. Our setup should allow for hyperspectral imaging of tissue and cells in real time.

AMISS - Active and passive MIcrowaves for Security and Subsurface imaging

Science.gov (United States)

Soldovieri, Francesco; Slob, Evert; Turk, Ahmet Serdar; Crocco, Lorenzo; Catapano, Ilaria; Di Matteo, Francesca

2013-04-01

The FP7-IRSES project AMISS - Active and passive MIcrowaves for Security and Subsurface imaging is based on a well-combined network among research institutions of EU, Associate and Third Countries (National Research Council of Italy - Italy, Technische Universiteit Delft - The Netherlands, Yildiz Technical University - Turkey, Bauman Moscow State Technical University - Russia, Usikov Institute for Radio-physics and Electronics and State Research Centre of Superconductive Radioelectronics "Iceberg" - Ukraine and University of Sao Paulo - Brazil) with the aims of achieving scientific advances in the framework of microwave and millimeter imaging systems and techniques for security and safety social issues. In particular, the involved partners are leaders in the scientific areas of passive and active imaging and are sharing their complementary knowledge to address two main research lines. The first one regards the design, characterization and performance evaluation of new passive and active microwave devices, sensors and measurement set-ups able to mitigate clutter and increase information content. The second line faces the requirements to make State-of-the-Art processing tools compliant with the instrumentations developed in the first line, suitable to work in electromagnetically complex scenarios and able to exploit the unexplored possibilities offered by new instrumentations. The main goals of the project are: 1) Development/improvement and characterization of new sensors and systems for active and passive microwave imaging; 2) Set up, analysis and validation of state of art/novel data processing approach for GPR in critical infrastructure and subsurface imaging; 3) Integration of state of art and novel imaging hardware and characterization approaches to tackle realistic situations in security, safety and subsurface prospecting applications; 4) Development and feasibility study of bio-radar technology (system and data processing) for vital signs detection and

Imaging the Subsurface with Upgoing Muons

Science.gov (United States)

Bonal, N.; Preston, L. A.; Schwellenbach, D.; Dreesen, W.; Green, A.

2014-12-01

We assess the feasibility of imaging the subsurface using upgoing muons. Traditional muon imaging focuses on more-prevalent downgoing muons. Muons are subatomic particles capable of penetrating the earth's crust several kilometers. Downgoing muons have been used to image the Pyramid of Khafre of Giza, various volcanoes, and smaller targets like cargo. Unfortunately, utilizing downgoing muons requires below-target detectors. For aboveground objects like a volcano, the detector is placed at the volcano's base and the top portion of the volcano is imaged. For underground targets like tunnels, the detector would have to be placed below the tunnel in a deeper tunnel or adjacent borehole, which can be costly and impractical for some locations. Additionally, detecting and characterizing subsurface features like voids from tunnels can be difficult. Typical characterization methods like sonar, seismic, and ground penetrating radar have shown mixed success. Voids have a marked density contrast with surrounding materials, so using methods sensitive to density variations would be ideal. High-energy cosmic ray muons are more sensitive to density variation than other phenomena, including gravity. Their absorption rate depends on the density of the materials through which they pass. Measurements of muon flux rate at differing directions provide density variations of the materials between the muon source (cosmic rays and neutrino interactions) and detector, much like a CAT scan. Currently, tomography using downgoing muons can resolve features to the sub-meter scale. We present results of exploratory work, which demonstrates that upgoing muon fluxes appear sufficient to achieve target detection within a few months. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Subsurface offset behaviour in velocity analysis with extended reflectivity images

NARCIS (Netherlands)

Mulder, W.A.

2012-01-01

Migration velocity analysis with the wave equation can be accomplished by focusing of extended migration images, obtained by introducing a subsurface offset or shift. A reflector in the wrong velocity model will show up as a curve in the extended image. In the correct model, it should collapse to a

Ultrahigh speed endoscopic optical coherence tomography for gastroenterology.

Science.gov (United States)

Tsai, Tsung-Han; Lee, Hsiang-Chieh; Ahsen, Osman O; Liang, Kaicheng; Giacomelli, Michael G; Potsaid, Benjamin M; Tao, Yuankai K; Jayaraman, Vijaysekhar; Figueiredo, Marisa; Huang, Qin; Cable, Alex E; Fujimoto, James; Mashimo, Hiroshi

2014-12-01

We describe an ultrahigh speed endoscopic swept source optical coherence tomography (OCT) system for clinical gastroenterology using a vertical-cavity surface-emitting laser (VCSEL) and micromotor imaging catheter. The system had a 600 kHz axial scan rate and 8 µm axial resolution in tissue. Imaging was performed with a 3.2 mm diameter imaging catheter at 400 frames per second with a 12 µm spot size. Three-dimensional OCT (3D-OCT) imaging was performed in patients with a cross section of pathologies undergoing upper and lower endoscopy. The use of distally actuated imaging catheters enabled OCT imaging with more flexibility, such as volumetric imaging in the small intestine and the assessment of hiatal hernia using retroflex imaging. The high rotational scanning stability of the micromotor enabled 3D volumetric imaging with micron scale volumetric accuracy for both en face OCT and cross-sectional imaging, as well as OCT angiography (OCTA) for 3D visualization of subsurface microvasculature. The ability to perform both structural and functional 3D OCT imaging in the GI tract with microscopic accuracy should enable a wide range of studies and enhance the sensitivity and specificity of OCT for detecting pathology.

Flow mapping of multiphase flows using a novel single stem endoscopic particle image velocimetry instrument

International Nuclear Information System (INIS)

Lad, N; Adebayo, D; Aroussi, A

2011-01-01

Particle image velocimetry (PIV) is a successful flow mapping technique which can optically quantify large portions of a flow regime. This enables the method to be completely non-intrusive. The ability to be non-intrusive to any flow has allowed PIV to be used in a large range of industrial sectors for many applications. However, a fundamental disadvantage of the conventional PIV technique is that it cannot easily be used with flows which have no or limited optical access. Flows which have limited optical access for PIV measurement have been addressed using endoscopic PIV techniques. This system uses two separate probes which relay a light sheet and imaging optics to a planar position within the desired flow regime. This system is effective in medical and engineering applications. The present study has been involved in the development of a new endoscopic PIV system which integrates the illumination and imaging optics into one rigid probe. This paper focuses on the validation of the images taken from the novel single stem endoscopic PIV system. The probe is used within atomized spray flow and is compared with conventional PIV measurement and also pitot-static data. The endoscopic PIV system provides images which create localized velocity maps that are comparable with the global measurement of the conventional PIV system. The velocity information for both systems clearly show similar results for the spray characterization and are also validated using the pitot-static data

Simple fibre based dispersion management for two-photon excited fluorescence imaging through an endoscope

DEFF Research Database (Denmark)

Dimopoulos, Konstantinos; Marti, Dominik; Andersen, Peter E.

2018-01-01

We want to implement two-photon excitation fluorescence microscopy (TPEFM) into endoscopes, since TPEFM can provide relevant biomarkers for cancer staging and grading in hollow organs, endoscopically accessible through natural orifices. However, many obstacles must be overcome, among others...... the delivery of short laser pulses to the distal end of the endoscope. To this avail, we present imaging results using an all-fibre dispersion management scheme in a TPEFM setup. The scheme has been conceived by Jespersen et al. in 20101 and relies on the combination of a single mode fibre with normal...

Endoscopes with latest technology and concept.

Science.gov (United States)

Gotoh

2003-09-01

Endoscopic imaging systems that perform as the "eye" of the operator during endoscopic surgical procedures have developed rapidly due to various technological developments. In addition, since the most recent turn of the century robotic surgery has increased its scope through the utilization of systems such as Intuitive Surgical's da Vinci System. To optimize the imaging required for precise robotic surgery, a unique endoscope has been developed, consisting of both a two dimensional (2D) image optical system for wider observation of the entire surgical field, and a three dimensional (3D) image optical system for observation of the more precise details at the operative site. Additionally, a "near infrared radiation" endoscopic system is under development to detect the sentinel lymph node more readily. Such progress in the area of endoscopic imaging is expected to enhance the surgical procedure from both the patient's and the surgeon's point of view.

Laser scanning endoscope via an imaging fiber bundle for fluorescence imaging

Science.gov (United States)

Yeboah, Lorenz D.; Nestler, Dirk; Steiner, Rudolf W.

1994-12-01

Based on a laser scanning endoscope via an imaging fiber bundle, a new approach for a tumor diagnostic system has been developed to assist physicians in the diagnosis before the actual PDT is carried out. Laser induced, spatially resolved fluorescence images of diseased tissue can be compared with images received by video endoscopy using a white light source. The set- up is required to produce a better contrast between infected and healthy tissue and might serve as a constructive diagnostic help for surgeons. The fundamental idea is to scan a low-power laser beam on an imaging fiber bundle and to achieve a spatially resolved projection on the tissue surface. A sufficiently high laser intensity from the diode laser is concentrated on each single spot of the tissue exciting fluorescence when a dye has previously been accumulated. Subsequently, video image of the tissue is recorded and stored. With an image processing unit, video and fluorescence images are overlaid producing a picture of the fluorescence intensity in the environment of the observed tissue.

Chromaticity based smoke removal in endoscopic images

Science.gov (United States)

Tchaka, Kevin; Pawar, Vijay M.; Stoyanov, Danail

2017-02-01

In minimally invasive surgery, image quality is a critical pre-requisite to ensure a surgeons ability to perform a procedure. In endoscopic procedures, image quality can deteriorate for a number of reasons such as fogging due to the temperature gradient after intra-corporeal insertion, lack of focus and due to smoke generated when using electro-cautery to dissect tissues without bleeding. In this paper we investigate the use of vision processing techniques to remove surgical smoke and improve the clarity of the image. We model the image formation process by introducing a haze medium to account for the degradation of visibility. For simplicity and computational efficiency we use an adapted dark-channel prior method combined with histogram equalization to remove smoke artifacts to recover the radiance image and enhance the contrast and brightness of the final result. Our initial results on images from robotic assisted procedures are promising and show that the proposed approach may be used to enhance image quality during surgery without additional suction devices. In addition, the processing pipeline may be used as an important part of a robust surgical vision pipeline that can continue working in the presence of smoke.

Clinical Evaluation of Endoscopic Trimodal Imaging for the Detection and Differentiation of Colonic Polyps

NARCIS (Netherlands)

van den Broek, Frank J. C.; Fockens, Paul; van Eeden, Susanne; Kara, Mohammed A.; Hardwick, James C. H.; Reitsma, Johannes B.; Dekker, Evelien

2009-01-01

Background & Aims: Endoscopic trimodal imaging (ETMI) incorporates high-resolution endoscopy (HRE) and autofluorescence imaging (AFI) for adenoma detection, and narrow-band imaging (NBI) for differentiation of adenomas from nonneoplastic polyps. The aim of this study was to compare AFI with HRE for

Polymer Optical Fibre Sensors for Endoscopic Opto-Acoustic Imaging

DEFF Research Database (Denmark)

Broadway, Christian; Gallego, Daniel; Woyessa, Getinet

2015-01-01

in existing publications. A great advantage can be obtained for endoscopy due to a small size and array potential to provide discrete imaging speed improvements. Optical fibre exhibits numerous advantages over conventional piezo-electric transducers, such as immunity from electromagnetic interference...... is the physical size of the device, allowing compatibility with current technology, while governing flexibility of the distal end of the endoscope based on the needs of the sensor. Polymer optical fibre (POF) presents a novel approach for endoscopic applications and has been positively discussed and compared...... and a higher resolution at small sizes. Furthermore, micro structured polymer optical fibres offer over 12 times the sensitivity of silica fibre. We present a polymer fibre Bragg grating ultrasound detector with a core diameter of 125 microns. We discuss the ultrasonic signals received and draw conclusions...

Pancreas imaging by computed tomography after endoscopic retrograde pancreatography

International Nuclear Information System (INIS)

Frick, M.P.; O'Leary, J.F.; Salomonowitz, E.; Stoltenberg, E.; Hutton, S.; Gedgaudas, E.

1984-01-01

A method using CT after endoscopic retrograde pancreatography (CT-ERP) is described for pancreatic imaging. When using an ERP technique in the canine model comparable to that used in humans, small amounts of contrast material in peripheral pancreatic radicles resulted in enhancement of the pancreas on CT scans. Nine patients were also studied by CT-ERP images. The main pancreatic duct was seen on delayed images. In cases of chronic pancreatitis (n = 2), pancreatic opacification was patchy and heterogeneous. There was no contrast-material enhancement in areas of pancreatic carcimomas (n = 2). CT-ERP showed the true extent of carcinoma better than ERP alone

Electrical Resistance Tomography for Subsurface Imaging. Innovative Technology Summary Report

International Nuclear Information System (INIS)

None

2000-01-01

Electrical Resistance Tomography (ERT) noninvasively maps the 3-D resistivity field in the subsurface. It can be used on a scale from feet to kilometers. The 3-D resistivity field can be used to infer subsurface hydrogeological features and provides good resolution mapping of confining layers of various types. ERT imaging has been used for real-time monitoring and process control of remediation processes such as soil heating, pump and treat, steam injection, electrokinetics, Dynamic Underground Stripping (TechID 7), Hydrous Pyrolysis/Oxidation (TechID 1519) and more. ERT can be deployed via rapid and inexpensive installation of electrodes using a Cone Penetrometer (TechID 243). Additional applications are described under TechID 140 (Tanks) and TechID 2120 (Injected Subsurface Barriers); see also the related technology TechID 2121 (EIT)

A standardized imaging protocol for the endoscopic prediction of dysplasia within sessile serrated polyps (with video).

Science.gov (United States)

Tate, David J; Jayanna, Mahesh; Awadie, Halim; Desomer, Lobke; Lee, Ralph; Heitman, Steven J; Sidhu, Mayenaaz; Goodrick, Kathleen; Burgess, Nicholas G; Mahajan, Hema; McLeod, Duncan; Bourke, Michael J

2018-01-01

Dysplasia within sessile serrated polyps (SSPs) is difficult to detect and may be mistaken for an adenoma, risking incomplete resection of the background serrated tissue, and is strongly implicated in interval cancer after colonoscopy. The use of endoscopic imaging to detect dysplasia within SSPs has not been systematically studied. Consecutively detected SSPs ≥8 mm in size were evaluated by using a standardized imaging protocol at a tertiary-care endoscopy center over 3 years. Lesions suspected as SSPs were analyzed with high-definition white light then narrow-band imaging. A demarcated area with a neoplastic pit pattern (Kudo type III/IV, NICE type II) was sought among the serrated tissue. If this was detected, the lesion was labeled dysplastic (sessile serrated polyp with dysplasia); if not, it was labeled non-dysplastic (sessile serrated polyp without dysplasia). Histopathology was reviewed by 2 blinded specialist GI pathologists. A total of 141 SSPs were assessed in 83 patients. Median lesion size was 15.0 mm (interquartile range 10-20), and 54.6% were in the right side of the colon. Endoscopic evidence of dysplasia was detected in 36 of 141 (25.5%) SSPs; of these, 5 of 36 (13.9%) lacked dysplasia at histopathology. Two of 105 (1.9%) endoscopically designated non-dysplastic SSPs had dysplasia at histopathology. Endoscopic imaging, therefore, had an accuracy of 95.0% (95% confidence interval [CI], 90.1%-97.6%) and a negative predictive value of 98.1% (95% CI, 92.6%-99.7%) for detection of dysplasia within SSPs. Dysplasia within SSPs can be detected accurately by using a simple, broadly applicable endoscopic imaging protocol that allows complete resection. Independent validation of this protocol and its dissemination to the wider endoscopic community may have a significant impact on rates of interval cancer. (Clinical trial registration number: NCT03100552.). Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All

Eyewear-style three-dimensional endoscope derived from microstructured polymer fiber with the function of image transmission

International Nuclear Information System (INIS)

Kong De-Peng; Wang Li-Li; He Zheng-Quan; Ma Tian; Chu Jiu-Rong

2013-01-01

A method of fabricating multi-core polymer image fiber is proposed. Image fiber preform is fabricated by stacking thousands of polymer fibers each with a 0.25-mm diameter orderly in a die by only one step. The preform is heated and stretched into image fiber with an outer diameter of 2 mm. Then a portable eyewear-style three-dimensional (3D) endoscope system is designed, fabricated, and characterized. This endoscopic system is composed of two graded index lenses, two pieces of 0.35-m length image guide fibers, and a pair of oculars. It shows good flexibility and portability, and can provide the depth information accordingly. (general)

Integrated endoscopic OCT system and in-vivo images of human internal organs

Science.gov (United States)

Sergeev, Alexander M.; Gelikonov, Valentin M.; Gelikonov, Grigory V.; Feldchtein, Felix I.; Kuranov, Roman V.; Gladkova, Natalia D.; Shakhova, Natalia M.; Snopova, Ludmila; Shakhov, Andrei; Kuznetzova, Irina N.; Denisenko, Arkady; Pochinko, Vitaly; Chumakov, Yuri; Almasov, Valentin

1998-04-01

First results of endoscopic applications of optical coherence tomography (OCT) for in vivo studies of human mucosa in respiratory, gastrointestinal, urinary and genital tracts are presented. A novel endoscopic OCT (EOCT) system has been created that is based on the integration of a sampling arm of an all-optical-fiber interferometer into standard endoscopic devices using their biopsy channel to transmit low-coherence radiation to investigated tissue. We have studied mucous membranes of esophagus, larynx, stomach, urinary bladder, uterine cervix and endometrium as typical localization for carcinomatous processes. Images of tumor tissues versus healthy tissues have been recorded and analyzed. Violations of well-defined stratified healthy mucosa structure in cancered tissue is distinctly seen by EOCT, thus making this technique promising for early diagnosis of tumors and precise guiding of excisional biopsy.

SU-C-18A-02: Image-Based Camera Tracking: Towards Registration of Endoscopic Video to CT

International Nuclear Information System (INIS)

Ingram, S; Rao, A; Wendt, R; Castillo, R; Court, L; Yang, J; Beadle, B

2014-01-01

Purpose: Endoscopic examinations are routinely performed on head and neck and esophageal cancer patients. However, these images are underutilized for radiation therapy because there is currently no way to register them to a CT of the patient. The purpose of this work is to develop a method to track the motion of an endoscope within a structure using images from standard clinical equipment. This method will be incorporated into a broader endoscopy/CT registration framework. Methods: We developed a software algorithm to track the motion of an endoscope within an arbitrary structure. We computed frame-to-frame rotation and translation of the camera by tracking surface points across the video sequence and utilizing two-camera epipolar geometry. The resulting 3D camera path was used to recover the surrounding structure via triangulation methods. We tested this algorithm on a rigid cylindrical phantom with a pattern spray-painted on the inside. We did not constrain the motion of the endoscope while recording, and we did not constrain our measurements using the known structure of the phantom. Results: Our software algorithm can successfully track the general motion of the endoscope as it moves through the phantom. However, our preliminary data do not show a high degree of accuracy in the triangulation of 3D point locations. More rigorous data will be presented at the annual meeting. Conclusion: Image-based camera tracking is a promising method for endoscopy/CT image registration, and it requires only standard clinical equipment. It is one of two major components needed to achieve endoscopy/CT registration, the second of which is tying the camera path to absolute patient geometry. In addition to this second component, future work will focus on validating our camera tracking algorithm in the presence of clinical imaging features such as patient motion, erratic camera motion, and dynamic scene illumination

Geophysical data fusion for subsurface imaging

International Nuclear Information System (INIS)

Hoekstra, P.; Vandergraft, J.; Blohm, M.; Porter, D.

1993-08-01

A geophysical data fusion methodology is under development to combine data from complementary geophysical sensors and incorporate geophysical understanding to obtain three dimensional images of the subsurface. The research reported here is the first phase of a three phase project. The project focuses on the characterization of thin clay lenses (aquitards) in a highly stratified sand and clay coastal geology to depths of up to 300 feet. The sensor suite used in this work includes time-domain electromagnetic induction (TDEM) and near surface seismic techniques. During this first phase of the project, enhancements to the acquisition and processing of TDEM data were studied, by use of simulated data, to assess improvements for the detection of thin clay layers. Secondly, studies were made of the use of compressional wave and shear wave seismic reflection data by using state-of-the-art high frequency vibrator technology. Finally, a newly developed processing technique, called ''data fusion,'' was implemented to process the geophysical data, and to incorporate a mathematical model of the subsurface strata. Examples are given of the results when applied to real seismic data collected at Hanford, WA, and for simulated data based on the geology of the Savannah River Site

New Insights on Subsurface Imaging of Carbon Nanotubes in Polymer Composites via Scanning Electron Microscopy

Science.gov (United States)

Zhao, Minhua; Ming, Bin; Kim, Jae-Woo; Gibbons, Luke J.; Gu, Xiaohong; Nguyen, Tinh; Park, Cheol; Lillehei, Peter T.; Villarrubia, J. S.; Vladar, Andras E.;

Augmented Endoscopic Images Overlaying Shape Changes in Bone Cutting Procedures.

Science.gov (United States)

Nakao, Megumi; Endo, Shota; Nakao, Shinichi; Yoshida, Munehito; Matsuda, Tetsuya

2016-01-01

In microendoscopic discectomy for spinal disorders, bone cutting procedures are performed in tight spaces while observing a small portion of the target structures. Although optical tracking systems are able to measure the tip of the surgical tool during surgery, the poor shape information available during surgery makes accurate cutting difficult, even if preoperative computed tomography and magnetic resonance images are used for reference. Shape estimation and visualization of the target structures are essential for accurate cutting. However, time-varying shape changes during cutting procedures are still challenging issues for intraoperative navigation. This paper introduces a concept of endoscopic image augmentation that overlays shape changes to support bone cutting procedures. This framework handles the history of the location of the measured drill tip as a volume label and visualizes the remains to be cut overlaid on the endoscopic image in real time. A cutting experiment was performed with volunteers, and the feasibility of this concept was examined using a clinical navigation system. The efficacy of the cutting aid was evaluated with respect to the shape similarity, total moved distance of a cutting tool, and required cutting time. The results of the experiments showed that cutting performance was significantly improved by the proposed framework.

Automatic classification of minimally invasive instruments based on endoscopic image sequences

Science.gov (United States)

Speidel, Stefanie; Benzko, Julia; Krappe, Sebastian; Sudra, Gunther; Azad, Pedram; Müller-Stich, Beat Peter; Gutt, Carsten; Dillmann, Rüdiger

2009-02-01

Minimally invasive surgery is nowadays a frequently applied technique and can be regarded as a major breakthrough in surgery. The surgeon has to adopt special operation-techniques and deal with difficulties like the complex hand-eye coordination and restricted mobility. To alleviate these constraints we propose to enhance the surgeon's capabilities by providing a context-aware assistance using augmented reality techniques. To analyze the current situation for context-aware assistance, we need intraoperatively gained sensor data and a model of the intervention. A situation consists of information about the performed activity, the used instruments, the surgical objects, the anatomical structures and defines the state of an intervention for a given moment in time. The endoscopic images provide a rich source of information which can be used for an image-based analysis. Different visual cues are observed in order to perform an image-based analysis with the objective to gain as much information as possible about the current situation. An important visual cue is the automatic recognition of the instruments which appear in the scene. In this paper we present the classification of minimally invasive instruments using the endoscopic images. The instruments are not modified by markers. The system segments the instruments in the current image and recognizes the instrument type based on three-dimensional instrument models.

Target-oriented retrieval of subsurface wave fields - Pushing the resolution limits in seismic imaging

Science.gov (United States)

Vasconcelos, Ivan; Ozmen, Neslihan; van der Neut, Joost; Cui, Tianci

2017-04-01

Travelling wide-bandwidth seismic waves have long been used as a primary tool in exploration seismology because they can probe the subsurface over large distances, while retaining relatively high spatial resolution. The well-known Born resolution limit often seems to be the lower bound on spatial imaging resolution in real life examples. In practice, data acquisition cost, time constraints and other factors can worsen the resolution achieved by wavefield imaging. Could we obtain images whose resolution beats the Born limits? Would it be practical to achieve it, and what are we missing today to achieve this? In this talk, we will cover aspects of linear and nonlinear seismic imaging to understand elements that play a role in obtaining "super-resolved" seismic images. New redatuming techniques, such as the Marchenko method, enable the retrieval of subsurface fields that include multiple scattering interactions, while requiring relatively little knowledge of model parameters. Together with new concepts in imaging, such as Target-Enclosing Extended Images, these new redatuming methods enable new targeted imaging frameworks. We will make a case as to why target-oriented approaches to reconstructing subsurface-domain wavefields from surface data may help in increasing the resolving power of seismic imaging, and in pushing the limits on parameter estimation. We will illustrate this using a field data example. Finally, we will draw connections between seismic and other imaging modalities, and discuss how this framework could be put to use in other applications

Classification of endoscopic capsule images by using color wavelet features, higher order statistics and radial basis functions.

Science.gov (United States)

Lima, C S; Barbosa, D; Ramos, J; Tavares, A; Monteiro, L; Carvalho, L

2008-01-01

This paper presents a system to support medical diagnosis and detection of abnormal lesions by processing capsule endoscopic images. Endoscopic images possess rich information expressed by texture. Texture information can be efficiently extracted from medium scales of the wavelet transform. The set of features proposed in this paper to code textural information is named color wavelet covariance (CWC). CWC coefficients are based on the covariances of second order textural measures, an optimum subset of them is proposed. Third and forth order moments are added to cope with distributions that tend to become non-Gaussian, especially in some pathological cases. The proposed approach is supported by a classifier based on radial basis functions procedure for the characterization of the image regions along the video frames. The whole methodology has been applied on real data containing 6 full endoscopic exams and reached 95% specificity and 93% sensitivity.

The potential of imaging subsurface heterogeneities by local, natural earthquakes

NARCIS (Netherlands)

Nishitsuji, Y.; Doi, I.; Draganov, D.S.

2014-01-01

We have developed a new imaging technique of subsurface heterogeneities that uses Sp-waves from natural earthquakes. This technique can be used as a first screening tool in frontier exploration areas before conventional active exploration. Analyzing Sp-waves from 28 earthquakes (Mj 2.0 to 4.2)

Micromotor endoscope catheter for in vivo, ultrahigh-resolution optical coherence tomography

Science.gov (United States)

Herz, P. R.; Chen, Y.; Aguirre, A. D.; Schneider, K.; Hsiung, P.; Fujimoto, J. G.; Madden, K.; Schmitt, J.; Goodnow, J.; Petersen, C.

2004-10-01

A distally actuated, rotational-scanning micromotor endoscope catheter probe is demonstrated for ultrahigh-resolution in vivo endoscopic optical coherence tomography (OCT) imaging. The probe permits focus adjustment for visualization of tissue morphology at varying depths with improved transverse resolution compared with standard OCT imaging probes. The distal actuation avoids nonuniform scanning motion artifacts that are present with other probe designs and can permit a wider range of imaging speeds. Ultrahigh-resolution endoscopic imaging is demonstrated in a rabbit with micromotor endoscope catheter probe promises to improve OCT imaging performance in future endoscopic imaging applications.

Mitigating fluorescence spectral overlap in wide-field endoscopic imaging

Science.gov (United States)

Hou, Vivian; Nelson, Leonard Y.; Seibel, Eric J.

2013-01-01

Abstract. The number of molecular species suitable for multispectral fluorescence imaging is limited due to the overlap of the emission spectra of indicator fluorophores, e.g., dyes and nanoparticles. To remove fluorophore emission cross-talk in wide-field multispectral fluorescence molecular imaging, we evaluate three different solutions: (1) image stitching, (2) concurrent imaging with cross-talk ratio subtraction algorithm, and (3) frame-sequential imaging. A phantom with fluorophore emission cross-talk is fabricated, and a 1.2-mm ultrathin scanning fiber endoscope (SFE) is used to test and compare these approaches. Results show that fluorophore emission cross-talk could be successfully avoided or significantly reduced. Near term, the concurrent imaging method of wide-field multispectral fluorescence SFE is viable for early stage cancer detection and localization in vivo. Furthermore, a means to enhance exogenous fluorescence target-to-background ratio by the reduction of tissue autofluorescence background is demonstrated. PMID:23966226

Endoscopic Tri-Modal Imaging (ETMI With Optical Magnification in the Detection of Barrett's Early Neoplasia

Directory of Open Access Journals (Sweden)

Sarmed S. Sami

2014-01-01

Full Text Available Early lesion detection and characterisation is vital to ensure accurate management in patients with gastrointestinal neoplasia. Endoscopic Tri-modal Imaging (ETMI technology has been shown to improve the targeted detection of early dysplastic lesions in Barrett's Oesophagus, but these results were not confirmed in non-expert hands [1]. This technology incorporates high resolution while light endoscopy (HRE, Auto Fluorescence Imaging (AFI and Narrow Band Imaging (NBI in one endoscope. The mucosa is first inspected with HRE, and then AFI is switched on to help in highlighting any suspicious areas in the mucosa [2]. These areas can be further examined by switching to NBI mode with magnification which helps to characterise mucosal patterns and identify early neoplasia [3].

In vivo endoscopic OCT imaging of precancer and cancer states of human mucosa

Science.gov (United States)

Sergeev, Alexander M.; Gelikonov, V. M.; Gelikonov, G. V.; Feldchtein, Felix I.; Kuranov, R. V.; Gladkova, N. D.; Shakhova, N. M.; Snopova, L. B.; Shakhov, A. V.; Kuznetzova, I. A.; Denisenko, A. N.; Pochinko, V. V.; Chumakov, Yu P.; Streltzova, O. S.

1997-12-01

First results of endoscopic applications of optical coherence tomography for in vivo studies of human mucosa in respiratory, gastrointestinal, urinary and genital tracts are presented. A novel endoscopic OCT (EOCT) system has been created that is based on the integration of a sampling arm of an all-optical-fiber interferometer into standard endoscopic devices using their biopsy channel to transmit low-coherence radiation to investigated tissue. We have studied mucous membranes of esophagus, larynx, stomach, urinary bladder, uterine cervix and body as typical localization for carcinomatous processes. Images of tumor tissues versus healthy tissues have been recorded and analyzed. Violations of well-defined stratified healthy mucosa structure in cancered tissue are distinctly seen by EOCT, thus making this technique promising for early diagnosis of tumors and precise guiding of excisional biopsy.

endoscope-i: an innovation in mobile endoscopic technology transforming the delivery of patient care in otolaryngology.

Science.gov (United States)

Mistry, N; Coulson, C; George, A

2017-11-01

Digital and mobile device technology in healthcare is a growing market. The introduction of the endoscope-i, the world's first endoscopic mobile imaging system, allows the acquisition of high definition images of the ear, nose and throat (ENT). The system combines the e-i Pro camera app with a bespoke engineered endoscope-i adaptor which fits securely onto the iPhone or iPod touch. Endoscopic examination forms a salient aspect of the ENT work-up. The endoscope-i therefore provides a mobile and compact alternative to the existing bulky endoscopic systems currently in use which often restrict the clinician to the clinic setting. Areas covered: This article gives a detailed overview of the endoscope-i system together with its applications. A review and comparison of alternative devices on the market offering smartphone adapted endoscopic viewing systems is also presented. Expert commentary: The endoscope-i fulfils unmet needs by providing a compact, highly portable, simple to use endoscopic viewing system which is cost-effective and which makes use of smartphone technology most clinicians have in their pocket. The system allows real-time feedback to the patient and has the potential to transform the way that healthcare is delivered in ENT as well as having applications further afield.

Comparison of Narrowband Imaging with Autofluorescence Imaging for Endoscopic Visualization of Superficial Squamous Cell Carcinoma Lesions of the Esophagus

Directory of Open Access Journals (Sweden)

Haruhisa Suzuki

2012-01-01

Full Text Available Aim. To compare narrowband imaging (NBI and autofluorescence imaging (AFI endoscopic visualization for identifying superficial esophageal squamous cell carcinoma (SCC. Methods. Twenty-four patients with superficial esophageal carcinomas diagnosed at previous hospitals were enrolled in this study. Lesions were initially detected using white-light endoscopy and then observed with both NBI and AFI. Endoscopic images documented each method, and three endoscopists experienced in esophageal imaging retrospectively reviewed respective images of histologically confirmed esophageal SCCs. Images were assessed for quality in identifying superficial SCCs and rated as excellent, fair, or poor by the three reviewers with interobserver agreement calculated using kappa (κ statistics. Results. Thirty-one lesions histologically confirmed as superficial esophageal SCCs were detected in 24 patients. NBI images of 27 lesions (87% were rated as excellent, three as fair, and one as poor compared to AFI images of 19 lesions (61% rated as excellent, 10 as fair and two as poor (P<0.05. Moderate interobserver agreement (κ=0.42, 95% CI 0.24–0.60 resulted in NBI while fair agreement (κ=0.35, 95% CI 0.18–0.51 was achieved using AFI. Conclusion. NBI may be more effective than AFI for visualization of esophageal SCC.

Improved planning of endoscopic sinonasal surgery from 3-dimensional images with Osirix® and stereolithography.

Science.gov (United States)

Sánchez-Gómez, Serafín; Herrero-Salado, Tomás F; Maza-Solano, Juan M; Ropero-Romero, Francisco; González-García, Jaime; Ambrosiani-Fernández, Jesús

2015-01-01

The high variability of sinonasal anatomy requires the best knowledge of its three-dimensional (3D) conformation to perform surgery more safely and efficiently. The aim of the study was to validate the utility of Osirix® and stereolithography in improving endoscopic sinonasal surgery planning. Osirix® was used as a viewer and Digital Imaging and Communications in Medicine (DICOM) 3D imaging manager to improve planning for 114 sinonasal endoscopic operations with polyposis (86) and chronic rhinosinusitis (CRS) (28). Stereolithography rapid prototyping was used for 7 frontoethmoidal mucoceles. Using Osirix® and stereolithography, a greater number of anatomical structures were identified and this was done faster, with a statistically-significant clinical-radiological correlation (Pvirtual reality, allows surgeons to perform endoscopic sinonasal surgery with greater confidence and in less time than using 2D images. Residents also achieve surgical competence faster, more safely and with fewer complications. This beneficial impact is increased when the surgical team has stereolithography rapid prototyping in more complex cases. Copyright © 2014 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Development of CMOS Imager Block for Capsule Endoscope

International Nuclear Information System (INIS)

Shafie, S; Fodzi, F A M; Tung, L Q; Lioe, D X; Halin, I A; Hasan, W Z W; Jaafar, H

2014-01-01

This paper presents the development of imager block to be associated in a capsule endoscopy system. Since the capsule endoscope is used to diagnose gastrointestinal diseases, the imager block must be in small size which is comfortable for the patients to swallow. In this project, a small size 1.5 V button battery is used as the power supply while the voltage supply requirements for other components such as microcontroller and CMOS image sensor are higher. Therefore, a voltage booster circuit is proposed to boost up the voltage supply from 1.5 V to 3.3 V. A low power microcontroller is used to generate control pulses for the CMOS image sensor and to convert the 8-bits parallel data output to serial data to be transmitted to the display panel. The results show that the voltage booster circuit was able to boost the voltage supply from 1.5 V to 3.3 V. The microcontroller precisely controls the CMOS image sensor to produce parallel data which is then serialized again by the microcontroller. The serial data is then successfully translated to 2fps image and displayed on computer.

Endoscopic Cerenkov luminescence imaging: in vivo small animal tumor model validation

Science.gov (United States)

Song, Tianming; Bao, Chengpeng; Hu, Zhenhua; Wang, Kun; Liu, Xia; Tian, Jie

2015-03-01

Background: Cerenkov luminescence imaging (CLI) provides a great potential for clinical translation of optical molecular imaging techniques through using clinical approved radiotracers. However, it is difficult to obtain the Cerenkov luminescence signal of deeper biological tissues due to the small magnitude of the signal. To efficiently acquire the weak Cerenkov luminescence, we developed an endoscopic Cerenkov luminescence imaging (ECLI) system to reduce the in vivo imaging depth with minimum invasion, and validated the system on small animal tumor models. Methods: For the ECLI system, the laparoscope was connected to a high sensitive charge-couple device (CCD) camera (DU888+, Andor, UK) by a custom made adapter. We conducted a series of in vitro and in vivo experiments by use of the system. In the in vitro experiment, the endoscopic luminescence images of the 18F-FDG with various activities in EP tubes were acquired using ECLI system, and the sensitivity was compared with conventional CLI system. In the in vivo tumor experiment, 18F-FDG with the activity of 200μCi were intravenously injected into 3 tumor mice. Then the ECLI system was used to acquire the optical images for both non-invasive and invasive conditions. Conclusion: Experimental data showed the ECLI system could detect the 18F-FDG with the activity as low as 1μCi. Furthermore, our preliminary results indicated the possibility of ECLI technique for detecting Cerenkov signals inside the tumor tissue with deeper depth and guiding the surgical operation of tumor excision. We believe that this technique can help to accelerate the clinical translation of CLI.

Endoscopic hyperspectral imaging: light guide optimization for spectral light source

Science.gov (United States)

Browning, Craig M.; Mayes, Samuel; Rich, Thomas C.; Leavesley, Silas J.

2018-02-01

Hyperspectral imaging (HSI) is a technology used in remote sensing, food processing and documentation recovery. Recently, this approach has been applied in the medical field to spectrally interrogate regions of interest within respective substrates. In spectral imaging, a two (spatial) dimensional image is collected, at many different (spectral) wavelengths, to sample spectral signatures from different regions and/or components within a sample. Here, we report on the use of hyperspectral imaging for endoscopic applications. Colorectal cancer is the 3rd leading cancer for incidences and deaths in the US. One factor of severity is the miss rate of precancerous/flat lesions ( 65% accuracy). Integrating HSI into colonoscopy procedures could minimize misdiagnosis and unnecessary resections. We have previously reported a working prototype light source with 16 high-powered light emitting diodes (LEDs) capable of high speed cycling and imaging. In recent testing, we have found our current prototype is limited by transmission loss ( 99%) through the multi-furcated solid light guide (lightpipe) and the desired framerate (20-30 fps) could not be achieved. Here, we report on a series of experimental and modeling studies to better optimize the lightpipe and the spectral endoscopy system as a whole. The lightpipe was experimentally evaluated using an integrating sphere and spectrometer (Ocean Optics). Modeling the lightpipe was performed using Monte Carlo optical ray tracing in TracePro (Lambda Research Corp.). Results of these optimization studies will aid in manufacturing a revised prototype with the newly designed light guide and increased sensitivity. Once the desired optical output (5-10 mW) is achieved then the HIS endoscope system will be able to be implemented without adding onto the procedure time.

Application of artificial intelligence using a convolutional neural network for detecting gastric cancer in endoscopic images.

Science.gov (United States)

Hirasawa, Toshiaki; Aoyama, Kazuharu; Tanimoto, Tetsuya; Ishihara, Soichiro; Shichijo, Satoki; Ozawa, Tsuyoshi; Ohnishi, Tatsuya; Fujishiro, Mitsuhiro; Matsuo, Keigo; Fujisaki, Junko; Tada, Tomohiro

2018-07-01

Image recognition using artificial intelligence with deep learning through convolutional neural networks (CNNs) has dramatically improved and been increasingly applied to medical fields for diagnostic imaging. We developed a CNN that can automatically detect gastric cancer in endoscopic images. A CNN-based diagnostic system was constructed based on Single Shot MultiBox Detector architecture and trained using 13,584 endoscopic images of gastric cancer. To evaluate the diagnostic accuracy, an independent test set of 2296 stomach images collected from 69 consecutive patients with 77 gastric cancer lesions was applied to the constructed CNN. The CNN required 47 s to analyze 2296 test images. The CNN correctly diagnosed 71 of 77 gastric cancer lesions with an overall sensitivity of 92.2%, and 161 non-cancerous lesions were detected as gastric cancer, resulting in a positive predictive value of 30.6%. Seventy of the 71 lesions (98.6%) with a diameter of 6 mm or more as well as all invasive cancers were correctly detected. All missed lesions were superficially depressed and differentiated-type intramucosal cancers that were difficult to distinguish from gastritis even for experienced endoscopists. Nearly half of the false-positive lesions were gastritis with changes in color tone or an irregular mucosal surface. The constructed CNN system for detecting gastric cancer could process numerous stored endoscopic images in a very short time with a clinically relevant diagnostic ability. It may be well applicable to daily clinical practice to reduce the burden of endoscopists.

Endoscopic OCT for in-vivo imaging of precancer and cancer states of human mucosa

Science.gov (United States)

Sergeev, Alexander M.; Gelikonov, Valentin M.; Gelikonov, Grigory V.; Feldchtein, Felix I.; Kuranov, Roman V.; Gladkova, Natalia D.; Shakhova, Natalia M.; Kuznetzova, Irina N.; Snopova, Ludmila; Denisenko, Arkady; Almasov, Valentin

1998-01-01

First results of endoscopic applications of optical coherence tomography for in vivo studies of human mucosa in gastrointestinal and genital tracts are presented. A novel endoscopic OCT system has ben created that is based on the integration of a sampling arm of an all-optical-fiber interferometer into standard endoscopic devices using their biopsy channel to transmit low-coherence radiation to investigated tissue. We have studied mucous membranes of esophagus, stomach and uterine cervix as typical localization for carcinomatous processes. Images of tumor tissues versus healthy tissues have been recorded and analyzed. Violations of well-defined stratified healthy mucosa structure in cancerous tissue is distinctly seen by EOCT, thus making this technique promising for early diagnosis of tumors and precise guiding of excisional biopsy.

Method for radiometric calibration of an endoscope's camera and light source

Science.gov (United States)

Rai, Lav; Higgins, William E.

2008-03-01

An endoscope is a commonly used instrument for performing minimally invasive visual examination of the tissues inside the body. A physician uses the endoscopic video images to identify tissue abnormalities. The images, however, are highly dependent on the optical properties of the endoscope and its orientation and location with respect to the tissue structure. The analysis of endoscopic video images is, therefore, purely subjective. Studies suggest that the fusion of endoscopic video images (providing color and texture information) with virtual endoscopic views (providing structural information) can be useful for assessing various pathologies for several applications: (1) surgical simulation, training, and pedagogy; (2) the creation of a database for pathologies; and (3) the building of patient-specific models. Such fusion requires both geometric and radiometric alignment of endoscopic video images in the texture space. Inconsistent estimates of texture/color of the tissue surface result in seams when multiple endoscopic video images are combined together. This paper (1) identifies the endoscope-dependent variables to be calibrated for objective and consistent estimation of surface texture/color and (2) presents an integrated set of methods to measure them. Results show that the calibration method can be successfully used to estimate objective color/texture values for simple planar scenes, whereas uncalibrated endoscopes performed very poorly for the same tests.

Optical design of an optical coherence tomography and multispectral fluorescence imaging endoscope to detect early stage ovarian cancer

Science.gov (United States)

Tate, Tyler; Keenan, Molly; Swan, Elizabeth; Black, John; Utzinger, Urs; Barton, Jennifer

2014-12-01

The five year survival rate for ovarian cancer is over 90% if early detection occurs, yet no effective early screening method exists. We have designed and are constructing a dual modality Optical Coherence Tomography (OCT) and Multispectral Fluorescence Imaging (MFI) endoscope to optically screen the Fallopian tube and ovary for early stage cancer. The endoscope reaches the ovary via the natural pathway of the vagina, cervix, uterus and Fallopian tube. In order to navigate the Fallopian tube the endoscope must have an outer diameter of 600 μm, be highly flexible, steerable, tracking and nonperforating. The imaging systems consists of six optical subsystems, two from OCT and four from MFI. The optical subsystems have independent and interrelated design criteria. The endoscope will be tested on realistic tissue models and ex vivo tissue to prove feasibility of future human trials. Ultimately the project aims to provide women the first effective ovarian cancer screening technique.

Emphysema. Imaging for endoscopic lung volume reduction; Lungenemphysem. Bildgebung bei endoskopischer Lungenvolumenreduktion

Energy Technology Data Exchange (ETDEWEB)

Storbeck, B. [LungenClinic Grosshansdorf (Germany). Dept. of Radiology; Schroeder, T.H. [Amalie Sieveking-Hospital, Diagnostic and Interventional Radiology, Hamburg (Germany); Oldigs, M.; Rabe, K.F. [LungenClinic Grosshansdorf (Germany). Dept. of Pulmonology; Weber, C. [Amalie Sieveking-Hospital, Diagnostic and Interventional Radiology, Hamburg (Germany); University Medical Center Hamburg-Eppendorf (Germany). Diagnostic and Interventional Radiology

2015-07-15

Chronic obstructive pulmonary disease (COPD) is characterized by two entities, the more airway-predominant type (''bronchitis'') on the one hand, and emphysema-predominant type on the other. Imaging via high-resolution computed tomography plays an important role in phenotyping COPD. For patients with advanced lung emphysema, new endoscopic lung volume reduction therapies (ELVR) have been developed. Proper selection of suitable patients requires thin-section reconstruction of volumetric CT image data sets also in coronal and sagittal orientation are required. In the current manuscript we will describe emphysema subtypes (centrilobular, paraseptal, panlobular), options for quantifying emphysema and this importance of regional distribution (homogeneous or heterogeneous, target area) as this is crucial for patient selection. Analysis of the interlobular fissures is obligatory despite the lack of standardization, as incomplete fissures indicate collateral ventilation (CV) via parenchymal bridges, which is an important criterion in choosing endoscopic methods of LVR. Every radiologist should be familiar with modern LVR therapies such as valves and coils, and furthermore should know what a lung doctor expects from radiologic evaluation (before and after ELVR). Finally we present a checklist as a quick reference for all steps concerning imaging for ELVR.

The combination design for open and endoscopic surgery using fluorescence molecular imaging technology

Science.gov (United States)

Mao, Yamin; Jiang, Shixin; Ye, Jinzuo; An, Yu; Yang, Xin; Chi, Chongwei; Tian, Jie

2015-03-01

For clinical surgery, it is still a challenge to objectively determine tumor margins during surgery. With the development of medical imaging technology, fluorescence molecular imaging (FMI) method can provide real-time intraoperative tumor margin information. Furthermore, surgical navigation system based on FMI technology plays an important role for the aid of surgeons' precise tumor margin decision. However, detection depth is the most limitation exists in the FMI technique and the method convenient for either macro superficial detection or micro deep tissue detection is needed. In this study, we combined advantages of both open surgery and endoscopic imaging systems with FMI technology. Indocyanine green (ICG) experiments were performed to confirm the feasibility of fluorescence detection in our system. Then, the ICG signal was photographed in the detection area with our system. When the system connected with endoscope lens, the minimum quantity of ICG detected by our system was 0.195 ug. For aspect of C mount lens, the sensitivity of ICG detection with our system was 0.195ug. Our experiments results proved that it was feasible to detect fluorescence images with this combination method. Our system shows great potential in the clinical applications of precise dissection of various tumors

A novel fusion imaging system for endoscopic ultrasound

DEFF Research Database (Denmark)

Gruionu, Lucian Gheorghe; Saftoiu, Adrian; Gruionu, Gabriel

2016-01-01

BACKGROUND AND OBJECTIVE: Navigation of a flexible endoscopic ultrasound (EUS) probe inside the gastrointestinal (GI) tract is problematic due to the small window size and complex anatomy. The goal of the present study was to test the feasibility of a novel fusion imaging (FI) system which uses...... time was 24.6 ± 6.6 min, while the time to reach the clinical target was 8.7 ± 4.2 min. CONCLUSIONS: The FI system is feasible for clinical use, and can reduce the learning curve for EUS procedures and improve navigation and targeting in difficult anatomic locations....

High resolution axicon-based endoscopic FD OCT imaging with a large depth range

Science.gov (United States)

Lee, Kye-Sung; Hurley, William; Deegan, John; Dean, Scott; Rolland, Jannick P.

2010-02-01

Endoscopic imaging in tubular structures, such as the tracheobronchial tree, could benefit from imaging optics with an extended depth of focus (DOF). This optics could accommodate for varying sizes of tubular structures across patients and along the tree within a single patient. In the paper, we demonstrate an extended DOF without sacrificing resolution showing rotational images in biological tubular samples with 2.5 μm axial resolution, 10 ìm lateral resolution, and > 4 mm depth range using a custom designed probe.

Early Use of Magnetic Endoscopic Imaging by Novice Colonoscopists: Improved Performance without Increase in Workload

Directory of Open Access Journals (Sweden)

Sylvain Coderre

2010-01-01

Full Text Available BACKGROUND: Magnetic endoscopic imaging represents a recent advance in colonoscopy training. This technique provides adjunct information to the endoscopist, specifically with regard to colonoscope loop formation.

First Application of 7T Magnetic Resonance Imaging in Endoscopic Endonasal Surgery of Skull Base Tumors

Science.gov (United States)

Barrett, Thomas F; Dyvorne, Hadrien A; Padormo, Francesco; Pawha, Puneet S; Delman, Bradley N; Shrivastava, Raj K; Balchandani, Priti

2018-01-01

Background Successful endoscopic endonasal surgery for the resection of skull base tumors is reliant on preoperative imaging to delineate pathology from the surrounding anatomy. The increased signal-to-noise ratio afforded by 7T MRI can be used to increase spatial and contrast resolution, which may lend itself to improved imaging of skull base. In this study, we apply a 7T imaging protocol to patients with skull base tumors and compare the images to clinical standard of care. Methods Images were acquired at 7T on 11 patients with skull base lesions. Two neuroradiologists evaluated clinical 1.5T, 3T, and 7T scans for detection of intracavernous cranial nerves and ICA branches. Detection rates were compared. Images were utilized for surgical planning and uploaded to a neuronavigation platform and used to guide surgery. Results Image analysis yielded improved detection rates of cranial nerves and ICA branches at 7T. 7T images were successfully incorporated into preoperative planning and intraoperative neuronavigation. Conclusion Our study represents the first application of 7T MRI to the full neurosurgical workflow for endoscopic endonasal surgery. We detected higher rates of cranial nerves and ICA branches at 7T MRI compared to 3T and 1.5 T, and found that integration of 7T into surgical planning and guidance was feasible. These results suggest a potential for 7T MRI to reduce surgical complications. Future studies comparing standardized 7T, 3T, and 1.5 T MRI protocols in a larger number of patients are warranted to determine the relative benefit of 7T MRI for endonasal endoscopic surgical efficacy. PMID:28359922

First Application of 7-T Magnetic Resonance Imaging in Endoscopic Endonasal Surgery of Skull Base Tumors.

Science.gov (United States)

Barrett, Thomas F; Dyvorne, Hadrien A; Padormo, Francesco; Pawha, Puneet S; Delman, Bradley N; Shrivastava, Raj K; Balchandani, Priti

2017-07-01

Successful endoscopic endonasal surgery for the resection of skull base tumors is reliant on preoperative imaging to delineate pathology from the surrounding anatomy. The increased signal-to-noise ratio afforded by 7-T MRI can be used to increase spatial and contrast resolution, which may lend itself to improved imaging of the skull base. In this study, we apply a 7-T imaging protocol to patients with skull base tumors and compare the images with clinical standard of care. Images were acquired at 7 T on 11 patients with skull base lesions. Two neuroradiologists evaluated clinical 1.5-, 3-, and 7-T scans for detection of intracavernous cranial nerves and internal carotid artery (ICA) branches. Detection rates were compared. Images were used for surgical planning and uploaded to a neuronavigation platform and used to guide surgery. Image analysis yielded improved detection rates of cranial nerves and ICA branches at 7 T. The 7-T images were successfully incorporated into preoperative planning and intraoperative neuronavigation. Our study represents the first application of 7-T MRI to the full neurosurgical workflow for endoscopic endonasal surgery. We detected higher rates of cranial nerves and ICA branches at 7-T MRI compared with 3- and 1.5-T MRI, and found that integration of 7 T into surgical planning and guidance was feasible. These results suggest a potential for 7-T MRI to reduce surgical complications. Future studies comparing standardized 7-, 3-, and 1.5-T MRI protocols in a larger number of patients are warranted to determine the relative benefit of 7-T MRI for endonasal endoscopic surgical efficacy. Copyright © 2017 Elsevier Inc. All rights reserved.

Scoping the scope: endoscopic evaluation of endoscope working channels with a new high-resolution inspection endoscope (with video).

Science.gov (United States)

Barakat, Monique T; Girotra, Mohit; Huang, Robert J; Banerjee, Subhas

2018-02-06

Outbreaks of transmission of infection related to endoscopy despite reported adherence to reprocessing guidelines warrant scrutiny of all potential contributing factors. Recent reports from ambulatory surgery centers indicated widespread significant occult damage within endoscope working channels, raising concerns regarding the potential detrimental impact of this damage on the adequacy of endoscope reprocessing. We inspected working channels of all 68 endoscopes at our academic institution using a novel flexible inspection endoscope. Inspections were recorded and videos reviewed by 3 investigators to evaluate and rate channel damage and/or debris. Working channel rinsates were obtained from all endoscopes, and adenosine triphosphate (ATP) bioluminescence was measured. Overall endoscope working channel damage was rated as minimal and/or mild and was consistent with expected wear and tear (median 1.59 on our 5-point scale). Our predominant findings included superficial scratches (98.5%) and scratches with adherent peel (76.5%). No channel perforations, stains, or burns were detected. The extent of damage was not predicted by endoscope age. Minor punctate debris was common, and a few small drops of fluid were noted in 42.6% of endoscopes after reprocessing and drying. The presence of residual fluid predicted higher ATP bioluminescence values. The presence of visualized working channel damage or debris was not associated with elevated ATP bioluminescence values. The flexible inspection endoscope enables high-resolution imaging of endoscope working channels and offers endoscopy units an additional modality for endoscope surveillance, potentially complementing bacterial cultures and ATP values. Our study, conducted in a busy academic endoscopy unit, indicated predominately mild damage to endoscope working channels, which did not correlate with elevated ATP values. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights

Time-Lapse Electrical Resistivity Investigations for Imaging the Grouting Injection in Shallow Subsurface Cavities

Directory of Open Access Journals (Sweden)

Muhammad Farooq

2014-01-01

Full Text Available The highway of Yongweol-ri, Muan-gun, south-western part of the South Korean Peninsula, is underlain by the abandoned of subsurface cavities, which were discovered in 2005. These cavities lie at shallow depths with the range of 5∼15 meters below the ground surface. Numerous subsidence events have repeatedly occurred in the past few years, damaging infrastructure and highway. As a result of continuing subsidence issues, the Korean Institute of Geosciences and Mineral Resources (KIGAM was requested by local administration to resolve the issue. The KIGAM used geophysical methods to delineate subsurface cavities and improve more refined understanding of the cavities network in the study area. Cement based grouting has been widely employed in the construction industry to reinforce subsurface ground. In this research work, time-lapse electrical resistivity surveys were accomplished to monitor the grouting injection in the subsurface cavities beneath the highway, which have provided a quasi-real-time monitoring for modifying the subsurface cavities related to ground reinforcement, which would be difficult with direct methods. The results obtained from time-lapse electrical resistivity technique have satisfactory imaged the grouting injection experiment in the subsurface cavities beneath the highway. Furthermore, the borehole camera confirmed the presence of grouting material in the subsurface cavities, and hence this procedure increases the mechanical resistance of subsurface cavities below the highway.

Mobile depth profiling and sub-surface imaging techniques for historical paintings—A review

International Nuclear Information System (INIS)

Alfeld, Matthias; Broekaert, José A.C.

2013-01-01

Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed. - Highlights: • All mobile sub-surface and depth-profiling techniques for paintings are reviewed. • The number of techniques available has increased considerably in the last years. • X-ray radiography and infrared reflectography are still the most used techniques. • Scanning macro-XRF and optical coherence tomography begin to establish. • Industrial non destructive testing techniques support the preservation of paintings

Advances in interpretation of subsurface processes with time-lapse electrical imaging

Science.gov (United States)

Singha, Kaminit; Day-Lewis, Frederick D.; Johnson, Tim B.; Slater, Lee D.

2015-01-01

Electrical geophysical methods, including electrical resistivity, time-domain induced polarization, and complex resistivity, have become commonly used to image the near subsurface. Here, we outline their utility for time-lapse imaging of hydrological, geochemical, and biogeochemical processes, focusing on new instrumentation, processing, and analysis techniques specific to monitoring. We review data collection procedures, parameters measured, and petrophysical relationships and then outline the state of the science with respect to inversion methodologies, including coupled inversion. We conclude by highlighting recent research focused on innovative applications of time-lapse imaging in hydrology, biology, ecology, and geochemistry, among other areas of interest.

Towards automated visual flexible endoscope navigation.

Science.gov (United States)

van der Stap, Nanda; van der Heijden, Ferdinand; Broeders, Ivo A M J

2013-10-01

The design of flexible endoscopes has not changed significantly in the past 50 years. A trend is observed towards a wider application of flexible endoscopes with an increasing role in complex intraluminal therapeutic procedures. The nonintuitive and nonergonomical steering mechanism now forms a barrier in the extension of flexible endoscope applications. Automating the navigation of endoscopes could be a solution for this problem. This paper summarizes the current state of the art in image-based navigation algorithms. The objectives are to find the most promising navigation system(s) to date and to indicate fields for further research. A systematic literature search was performed using three general search terms in two medical-technological literature databases. Papers were included according to the inclusion criteria. A total of 135 papers were analyzed. Ultimately, 26 were included. Navigation often is based on visual information, which means steering the endoscope using the images that the endoscope produces. Two main techniques are described: lumen centralization and visual odometry. Although the research results are promising, no successful, commercially available automated flexible endoscopy system exists to date. Automated systems that employ conventional flexible endoscopes show the most promising prospects in terms of cost and applicability. To produce such a system, the research focus should lie on finding low-cost mechatronics and technologically robust steering algorithms. Additional functionality and increased efficiency can be obtained through software development. The first priority is to find real-time, robust steering algorithms. These algorithms need to handle bubbles, motion blur, and other image artifacts without disrupting the steering process.

Segmentation of Clinical Endoscopic Images Based on the Classification of Topological Vector Features

Directory of Open Access Journals (Sweden)

O. A. Dunaeva

2013-01-01

Full Text Available In this work, we describe a prototype of an automatic segmentation system and annotation of endoscopy images. The used algorithm is based on the classification of vectors of the topological features of the original image. We use the image processing scheme which includes image preprocessing, calculation of vector descriptors defined for every point of the source image and the subsequent classification of descriptors. Image preprocessing includes finding and selecting artifacts and equalizating the image brightness. In this work, we give the detailed algorithm of the construction of topological descriptors and the classifier creating procedure based on mutual sharing the AdaBoost scheme and a naive Bayes classifier. In the final section, we show the results of the classification of real endoscopic images.

Automated endoscopic navigation and advisory system from medical image

Science.gov (United States)

Kwoh, Chee K.; Khan, Gul N.; Gillies, Duncan F.

1999-05-01

In this paper, we present a review of the research conducted by our group to design an automatic endoscope navigation and advisory system. The whole system can be viewed as a two-layer system. The first layer is at the signal level, which consists of the processing that will be performed on a series of images to extract all the identifiable features. The information is purely dependent on what can be extracted from the 'raw' images. At the signal level, the first task is performed by detecting a single dominant feature, lumen. Few methods of identifying the lumen are proposed. The first method used contour extraction. Contours are extracted by edge detection, thresholding and linking. This method required images to be divided into overlapping squares (8 by 8 or 4 by 4) where line segments are extracted by using a Hough transform. Perceptual criteria such as proximity, connectivity, similarity in orientation, contrast and edge pixel intensity, are used to group edges both strong and weak. This approach is called perceptual grouping. The second method is based on a region extraction using split and merge approach using spatial domain data. An n-level (for a 2' by 2' image) quadtree based pyramid structure is constructed to find the most homogenous large dark region, which in most cases corresponds to the lumen. The algorithm constructs the quadtree from the bottom (pixel) level upward, recursively and computes the mean and variance of image regions corresponding to quadtree nodes. On reaching the root, the largest uniform seed region, whose mean corresponds to a lumen is selected that is grown by merging with its neighboring regions. In addition to the use of two- dimensional information in the form of regions and contours, three-dimensional shape can provide additional information that will enhance the system capabilities. Shape or depth information from an image is estimated by various methods. A particular technique suitable for endoscopy is the shape from shading

Endoscopic tri-modal imaging for detection of early neoplasia in Barrett's oesophagus: a multi-centre feasibility study using high-resolution endoscopy, autofluorescence imaging and narrow band imaging incorporated in one endoscopy system

NARCIS (Netherlands)

Curvers, W. L.; Singh, R.; Song, L.-M. Wong-Kee; Wolfsen, H. C.; Ragunath, K.; Wang, K.; Wallace, M. B.; Fockens, P.; Bergman, J. J. G. H. M.

2008-01-01

OBJECTIVE: To investigate the diagnostic potential of endoscopic tri-modal imaging and the relative contribution of each imaging modality (i.e. high-resolution endoscopy (HRE), autofluorescence imaging (AFI) and narrow-band imaging (NBI)) for the detection of early neoplasia in Barrett's oesophagus.

Mobile depth profiling and sub-surface imaging techniques for historical paintings—A review

Energy Technology Data Exchange (ETDEWEB)

Alfeld, Matthias, E-mail: matthias.alfeld@desy.de [University of Hamburg, Department of Chemistry, Martin-Luther-King Platz 6, D-20146 Hamburg (Germany); University of Antwerp, Department of Chemistry, Groenenbrogerlaan 171, B-2020 Antwerp (Belgium); Broekaert, José A.C., E-mail: jose.broekaert@chemie.uni-hamburg.de [University of Hamburg, Department of Chemistry, Martin-Luther-King Platz 6, D-20146 Hamburg (Germany)

2013-10-01

Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed. - Highlights: • All mobile sub-surface and depth-profiling techniques for paintings are reviewed. • The number of techniques available has increased considerably in the last years. • X-ray radiography and infrared reflectography are still the most used techniques. • Scanning macro-XRF and optical coherence tomography begin to establish. • Industrial non destructive testing techniques support the preservation of paintings.

Robot-assisted endoscope guidance versus manual endoscope guidance in functional endonasal sinus surgery (FESS).

Science.gov (United States)

Eichhorn, Klaus Wolfgang; Westphal, Ralf; Rilk, Markus; Last, Carsten; Bootz, Friedrich; Wahl, Friedrich; Jakob, Mark; Send, Thorsten

2017-10-01

Having one hand occupied with the endoscope is the major disadvantage for the surgeon when it comes to functional endoscopic sinus surgery (FESS). Only the other hand is free to use the surgical instruments. Tiredness or frequent instrument changes can thus lead to shaky endoscopic images. We collected the pose data (position and orientation) of the rigid 0° endoscope and all the instruments used in 16 FESS procedures with manual endoscope guidance as well as robot-assisted endoscope guidance. In combination with the DICOM CT data, we tracked the endoscope poses and workspaces using self-developed tracking markers. All surgeries were performed once with the robot and once with the surgeon holding the endoscope. Looking at the durations required, we observed a decrease in the operating time because one surgeon doing all the procedures and so a learning curve occurred what we expected. The visual inspection of the specimens showed no damages to any of the structures outside the paranasal sinuses. Robot-assisted endoscope guidance in sinus surgery is possible. Further CT data, however, are desirable for the surgical analysis of a tracker-based navigation within the anatomic borders. Our marker-based tracking of the endoscope as well as the instruments makes an automated endoscope guidance feasible. On the subjective side, we see that RASS brings a relief for the surgeon.

The Role of Adjunct Imaging in Endoscopic Detection of Dysplasia in Barrett's Esophagus.

Science.gov (United States)

Kandel, Pujan; Wallace, Michael B

2017-07-01

Advances in imaging technologies have demonstrated promise in early detection of dysplasia and cancer in Barrett's esophagus (BE). Optical chromoendoscopy, dye-based chromoendoscopy, and novel technologies have provided the opportunity to visualize the cellular and subcellular structures. Only narrow-band imaging and acetic acid chromoendoscopy have reached benchmarks for clinical use. Volumetric laser endomicroscopy and molecular imaging are not established for routine use. Best practice in management of BE should be focused on careful endoscopic examination, resection, or ablation of the entire abnormal lesion, as well as the use of available imaging technique that has good diagnostic accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

Mirizzi Syndrome with Endoscopic Ultrasound Image

Directory of Open Access Journals (Sweden)

K. Rayapudi

2013-05-01

Full Text Available We describe a 66-year-old Caucasian man with type 1 Mirizzi syndrome diagnosed on endoscopic ultrasound. He presented with acute onset of jaundice, malaise, dark urine over 3-4 days, and was found to have obstructive jaundice on lab testing. CT scan of the abdomen showed intrahepatic biliary ductal dilation, a 1.5 cm common bile duct (CBD above the pancreas, and possible stones in the CBD, but no masses. Endoscopic retrograde cholangiopancreatography (ERCP by a community gastroenterologist failed to cannulate the CBD. At the University Center, type 1 Mirizzi syndrome was noted on endoscopic ultrasound with narrowing of the CBD with extrinsic compression from cystic duct stone. During repeat ERCP, the CBD could be cannulated over the pancreatic duct wire. A mid CBD narrowing, distal CBD stones, proximal CBD and extrahepatic duct dilation were noted, and biliary sphincterotomy was performed. A small stone in the distal CBD was removed with an extraction balloon. The cystic duct stone was moved with the biliary balloon into the CBD, mechanical basket lithotripsy was performed and stone fragments were delivered out with an extraction balloon. The patient was seen 7 weeks later in the clinic. Skin and scleral icterus had cleared up and he is scheduled for an elective cholecystectomy. Mirizzi syndrome refers to biliary obstruction resulting from impacted stone in the cystic duct or neck of the gallbladder and commonly presents with obstructive jaundice. Type 1 does not have cholecystocholedochal fistulas, but they present in types 2, 3 and 4. Surgery is the mainstay of therapy. Endoscopic treatment is effective and can also be used as a temporizing measure or definitive treatment in poor surgical risk candidates.

Novel computer-based endoscopic camera

Science.gov (United States)

Rabinovitz, R.; Hai, N.; Abraham, Martin D.; Adler, Doron; Nissani, M.; Fridental, Ron; Vitsnudel, Ilia

1995-05-01

We have introduced a computer-based endoscopic camera which includes (a) unique real-time digital image processing to optimize image visualization by reducing over exposed glared areas and brightening dark areas, and by accentuating sharpness and fine structures, and (b) patient data documentation and management. The image processing is based on i Sight's iSP1000TM digital video processor chip and Adaptive SensitivityTM patented scheme for capturing and displaying images with wide dynamic range of light, taking into account local neighborhood image conditions and global image statistics. It provides the medical user with the ability to view images under difficult lighting conditions, without losing details `in the dark' or in completely saturated areas. The patient data documentation and management allows storage of images (approximately 1 MB per image for a full 24 bit color image) to any storage device installed into the camera, or to an external host media via network. The patient data which is included with every image described essential information on the patient and procedure. The operator can assign custom data descriptors, and can search for the stored image/data by typing any image descriptor. The camera optics has extended zoom range of f equals 20 - 45 mm allowing control of the diameter of the field which is displayed on the monitor such that the complete field of view of the endoscope can be displayed on all the area of the screen. All these features provide versatile endoscopic camera with excellent image quality and documentation capabilities.

[Study of Image Quality Comparison Based on the MTF Method Between Different Medical Rigid Endoscopes in an In Vitro Model].

Science.gov (United States)

Wang, Yunlong; Ji, Jun; Jiang, Changsong; Huang, Zengyue

2015-04-01

This study was aimed to use the method of modulation transfer function (MTF) to compare image quality among three different Olympus medical rigid cystoscopes in an in vitro model. During the experimental processes, we firstly used three different types of cystoscopes (i. e. OLYMPUS cystourethroscopy with FOV of 12 degrees, OLYMPUS Germany A22003A and OLYMPUS A2013A) to collect raster images at different brightness with industrial camera and computer from the resolution target which is with different spatial frequency, and then we processed the collected images using MALAB software with the optical transfer function MTF to obtain the values of MTF at different brightness and different spatial frequency. We then did data mathematical statistics and compared imaging quality. The statistical data showed that all three MTF values were smaller than 1. MTF values with the spatial frequency gradually increasing would decrease approaching 0 at the same brightness. When the brightness enhanced in the same process at the same spatial frequency, MTF values showed a slowly increasing trend. The three endoscopes' MTF values were completely different. In some cases the MTF values had a large difference, and the maximum difference could reach 0.7. Conclusion can be derived from analysis of experimental data that three Olympus medical rigid cystoscopes have completely different imaging quality abilities. The No. 3 endoscope OLYMPUS A2013A has low resolution but high contrast. The No. 1 endoscope OLYMPUS cystourethroscopy with FOV of 12 degrees, on the contrary, had high resolution and lower contrast. The No. 2 endoscope OLYMPUS Germany A22003A had high contrast and high resolution, and its image quality was the best.

Endoscopic inspection of steam turbines

International Nuclear Information System (INIS)

Maliniemi, H.; Muukka, E.

1990-01-01

For over ten years, Imatran Voima Oy (IVO) has developed, complementary inspection methods for steam turbine condition monitoring, which can be applied both during operation and shutdown. One important method used periodically during outages is endoscopic inspection. The inspection is based on the method where the internal parts of the turbine is inspected through access borings with endoscope and where the magnified figures of the internal parts is seen on video screen. To improve inspection assurance, an image-processing based pattern recognition method for cracks has been developed for the endoscopic inspection of turbine blades. It is based on the deduction conditions derived from the crack shape. The computer gives an alarm of a crack detection and prints a simulated image of the crack, which is then checked manually

FY1995 development of a endoscopic surgical system utilizing multi-modal functional images; 1995 nendo tashu kino gazo wo mochiiru teishinshu naishikyo shujutsu system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-05-01

The purpose of this study is to develop an endoscope system for neurosurgery that can provide not only conventional endoscopic images but also ultraviolet-visible spectra, fluorescence spectra, near infrared spectra, and ultra-soundimages of tissue aiming for real-time identification of pathological tissue. The system also incorporates surgical manipulator and devices such as micro forceps and laser surgical instruments for endoscopic image guided surgery. Surgical Manipulator should be a high performance and easy to operate surgical instrument as well as conventional surgical tools such as scissors and knife. Since living tissue deforms during surgical operation, pre-operative three dimensional information for registration of pathological tissue should be modified based on information obtained during surgery. Thus surgical manipulator should be operated under guidance of surgeon's observation. Consequently, surgical manipulator should have various types of imaging and measurement devices such as an endoscope and an ultrasound imaging probe at its end effectors. Based on this concept, a prototype of a new multi channel surgical manipulator system CM cube (CM3, Computer aided Micro Multichannel Manipulator) that has various types of imaging and measurement devices such as ultra-violet-visible camera for spectroscopic measurement, ultra-sound imaging probe, three dimensional endoscope, together with micro surgical instruments and laser surgical systems has been developed. Its performance was evaluated through in vitro/in vivo experiments and clinical application. (NEDO)

Wide-field phase imaging for the endoscopic detection of dysplasia and early-stage esophageal cancer

Science.gov (United States)

Fitzpatrick, C. R. M.; Gordon, G. S. D.; Sawyer, T. W.; Wilkinson, T. D.; Bohndiek, S. E.

2018-02-01

Esophageal cancer has a 5-year survival rate below 20%, but can be curatively resected if it is detected early. At present, poor contrast for early lesions in white light imaging leads to a high miss rate in standard-of- care endoscopic surveillance. Early lesions in the esophagus, referred to as dysplasia, are characterized by an abundance of abnormal cells with enlarged nuclei. This tissue has a different refractive index profile to healthy tissue, which results in different light scattering properties and provides a source of endogenous contrast that can be exploited for advanced endoscopic imaging. For example, point measurements of such contrast can be made with scattering spectroscopy, while optical coherence tomography generates volumetric data. However, both require specialist interpretation for diagnostic decision making. We propose combining wide-field phase imaging with existing white light endoscopy in order to provide enhanced contrast for dysplasia and early-stage cancer in an image format that is familiar to endoscopists. Wide-field phase imaging in endoscopy can be achieved using coherent illumination combined with phase retrieval algorithms. Here, we present the design and simulation of a benchtop phase imaging system that is compatible with capsule endoscopy. We have undertaken preliminary optical modelling of the phase imaging setup, including aberration correction simulations and an investigation into distinguishing between different tissue phantom scattering coefficients. As our approach is based on phase retrieval rather than interferometry, it is feasible to realize a device with low-cost components for future clinical implementation.

The establishment of enteral nutrition with minimally-invasive interventional procedure under endoscopic or imaging guidance

International Nuclear Information System (INIS)

Li Feng; Cheng Yingsheng

2010-01-01

For patients unable to get the necessary nutrition orally, a variety of techniques,including surgical way, to make gastrostomy with tube placement have been employed. For recent years, gastrostomy and tube placement with the help of endoscopic guidance or percutaneous interventional management has been developed, which is superior to surgical procedure in minimizing injuries, decreasing cost and reducing complications. In certain clinical situations, both endoscopic method and interventional method can be employed. This paper aims to make a comprehensive review of the indications, techniques and skills, advantages and disadvantages of both the endoscopy-guided and the imaging-guided percutaneous gastrojejunostomy for the establishment of enteral nutrition. (authors)

Systems workplace for endoscopic surgery.

Science.gov (United States)

Irion, K M; Novak, P

2000-01-01

With the advent of minimally invasive surgery (MIS) a decade ago, the requirements for operating rooms (OR) and their equipment have been increased. Compared with conventional open surgery, the new endoscopic techniques require additional tools. Television systems, for video-assisted image acquisition and visualisation, including cameras, monitors and light systems, as well as insufflators, pumps, high-frequency units, lasers and motorised therapy units, are nowadays usually made available on carts during endoscopic surgery. In conjunction with a set of endoscopic instruments, these high-tech units allow new operating techniques to be performed. The benefit for patients has become clear in recent years; however, the technical complexity of OR has also increased considerably. To minimise this problem for the OR personnel, the MIS concept 'OR1' (Operating Room 1) was developed and implemented. OR1 is a fully functional and integrated multi-speciality surgical suite for MIS. The centrepieces of the OR1 are the Storz Communication Bus (SCB) and the advanced image and data archiving system (Aida) from Karl Storz, Tuttlingen, Germany. Both components allow monitoring, access and networking of the MIS equipment and other OR facilities, as well as the acquisition, storage and display of image, patient and equipment data during the endoscopic procedure. A central user interface allows efficient, simplified operation and online clinical images. Due to the system integration, the handling of complex equipment is considerably simplified, logistical procedures in the OR are improved, procedure times are shorter and, particularly noteworthy, operative risk can be reduced through simplified device operation.

Subsurface probing

International Nuclear Information System (INIS)

Lytle, R.J.

1978-01-01

Imaging techniques that can be used to translate seismic and electromagnetic wave signals into visual representation are briefly discussed. The application of these techniques is illustrated on the example of determining the subsurface structure of a proposed power plant. Imaging makes the wave signals intelligible to the non-geologists. R and D work needed in this area are tabulated

Improving superficial target delineation in radiation therapy with endoscopic tracking and registration

Energy Technology Data Exchange (ETDEWEB)

Weersink, R. A.; Qiu, J.; Hope, A. J.; Daly, M. J.; Cho, B. C. J.; DaCosta, R. S.; Sharpe, M. B.; Breen, S. L.; Chan, H.; Jaffray, D. A. [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada) and Ontario Cancer Institute, University Health Network, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada) and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada and Ontario Cancer Institute, University Health Network, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada) and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5G 2M9 (Canada) and Ontario Cancer Institute, University Health Network, Toronto, Ontario M5G 2M9 (Canada)

2011-12-15

Purpose: Target delineation within volumetric imaging is a critical step in the planning process of intensity modulated radiation therapy. In endoluminal cancers, endoscopy often reveals superficial areas of visible disease beyond what is seen on volumetric imaging. Quantitatively relating these findings to the volumetric imaging is prone to human error during the recall and contouring of the target. We have developed a method to improve target delineation in the radiation therapy planning process by quantitatively registering endoscopic findings contours traced on endoscopic images to volumetric imaging. Methods: Using electromagnetic sensors embedded in an endoscope, 2D endoscopic images were registered to computed tomography (CT) volumetric images by tracking the position and orientation of the endoscope relative to a CT image set. Regions-of-interest (ROI) in the 2D endoscopic view were delineated. A mesh created within the boundary of the ROI was projected onto the 3D image data, registering the ROI with the volumetric image. This 3D ROI was exported to clinical radiation treatment planning software. The precision and accuracy of the procedure was tested on two solid phantoms with superficial markings visible on both endoscopy and CT images. The first phantom was T-shaped tube with X-marks etched on the interior. The second phantom was an anatomically correct skull phantom with a phantom superficial lesion placed on the pharyngeal surface. Markings were contoured on the endoscope images and compared with contours delineated in the treatment planning system based on the CT images. Clinical feasibility was tested on three patients with early stage glottic cancer. Image-based rendering using manually identified landmarks was used to improve the registration. Results: Using the T-shaped phantom with X-markings, the 2D to 3D registration accuracy was 1.5-3.5 mm, depending on the endoscope position relative to the markings. Intraobserver standard variation was 0

Duodenal endoscopic findings and histopathologic confirmation of intestinal lymphangiectasia in dogs.

Science.gov (United States)

Larson, R N; Ginn, J A; Bell, C M; Davis, M J; Foy, D S

2012-01-01

The diagnosis of intestinal lymphangiectasia (IL) has been associated with characteristic duodenal mucosal changes. However, the sensitivity and specificity of the endoscopic duodenal mucosal appearance for the diagnosis of IL are not reported. To evaluate the utility of endoscopic images of the duodenum for diagnosis of IL. Endoscopic appearance of the duodenal mucosal might predict histopathologic diagnosis of IL with a high degree of sensitivity and specificity. 51 dogs that underwent upper gastrointestinal (GI) endoscopy and endoscopic biopsies. Retrospective review of images acquired during endoscopy. Dogs were included if adequate biopsies were obtained during upper GI endoscopy and digital images were saved during the procedure. Images were assessed for the presence and severity of IL. Using histopathology as the gold standard, the sensitivity and specificity of endoscopy for diagnosing IL were calculated. Intestinal lymphangiectasia (IL) was diagnosed in 25/51 dogs. Gross endoscopic appearance of the duodenal mucosa had a sensitivity and specificity (95% confidence interval) of 68% (46%, 84%) and 42% (24%, 63%), respectively for diagnosis of IL. Endoscopic images in cases with lymphopenia, hypocholesterolemia, and hypoalbuminemia had a sensitivity of 80%. Endoscopic duodenal mucosa appearance alone lacks specificity and has only a moderate sensitivity for diagnosis of IL. Evaluation of biomarkers associated with PLE improved the sensitivity; however, poor specificity for diagnosis of IL supports the need for histopathologic confirmation. Copyright © 2012 by the American College of Veterinary Internal Medicine.

Anatomy of Old Faithful from subsurface seismic imaging of the Yellowstone Upper Geyser Basin

KAUST Repository

Wu, Sin-Mei

2017-10-03

The Upper Geyser Basin in Yellowstone National Park contains one of the highest concentrations of hydrothermal features on Earth including the iconic Old Faithful geyser. Although this system has been the focus of many geological, geochemical, and geophysical studies for decades, the shallow (<200 m) subsurface structure remains poorly characterized. To investigate the detailed subsurface geologic structure including the hydrothermal plumbing of the Upper Geyser Basin, we deployed an array of densely spaced three-component nodal seismographs in November of 2015. In this study, we extract Rayleigh-wave seismic signals between 1-10 Hz utilizing non-diffusive seismic waves excited by nearby active hydrothermal features with the following results. 1) imaging the shallow subsurface structure by utilizing stationary hydrothermal activity as a seismic source, 2) characterizing how local geologic conditions control the formation and location of the Old Faithful hydrothermal system, and 3) resolving a relatively shallow (10-60 m) and large reservoir located ~100 m southwest of Old Faithful geyser.

Study on multi-detector computed tomography in the virtual endoscope mode to phantom of saliva gland duct application. Image quality evaluation of geometry

International Nuclear Information System (INIS)

Ozawa, Tomonori; Innami, Hisashi; Oyake, Reira; Shinohara, Yuki; Yamaaki, Fumi; Koizumi, Nobuhide; Okumura, Yasuhiko

2009-01-01

The diagnosis ability of the radiographic imaging has been greatly improved by the advent of multi-detector computed tomography (MDCT), Which is now a the prerequisite to the diagnosis and treatment of a variety of diseases. MDCT conducted in the virtual endoscope mode can be used for various image compositions, and the space in a structure such as the large intestines can be visualized similarly as with an actual endoscope. Using a phantom of a salivary gland duct, I performed the image analysis to determine whether this endoscope mode could able to be applied to the oral cavity. I searched for the optimum conditions and the best position for taking pictures, and evaluated whether the salivary gland ducts could be reproducibly imitated by the phantom. Modulation transfer function (MTF), Wiener spectrum (WS) analysis were used to examined the utility of MDCT in the virtual endoscope mode for use in the oral cavity. As a result, the following conclusions were made: The best image was obtained within 40 mm from the center part of the gantry by the MTF and the WS analyses. Decreases in the MTF and the WS as the decrease were seen at 20 mAs and 80 kV, and the decrease were seen in the sharpness of the image decreased as the value of the reconstruction function became smaller. The image was somewhat distorted when pictures were taken of the parallel or the direction of the slice by the inclination within 90 deg±15 deg as much as possible Z axially for running of the duct in the evaluation of internal reproducibility. The influence was admitted to go out easily in an inside form as the inside diameter became thin. The salivary gland phantom was evaluated geometrically by MDCT in the virtual endoscope mode, and the optimal conditions were obtained from the above-mentioned results. The utility of MDCT in the mode was thus suggested. (author)

Endoscopic trans-nasal approach for biopsy of orbital tumors using image-guided neuro-navigation system

International Nuclear Information System (INIS)

Sieskiewicz, A.; Mariak, Z.; Rogowski, M.; Lyson, T.

2008-01-01

Histopathological diagnosis of intraorbital tumors is of crucial value for planning further therapy. The aim of the study was to explore clinical utility of image-guided endoscopy for biopsy of orbital tumors. Trans-nasal endoscopic biopsy of intraorbital mass lesions was performed in 6 patients using a neuro-navigation system (Medtronic Stealth Station Treon plus). The CT and MRI 1 mm slice images were fused by the system in order to visualise both bony and soft tissue structures. The anatomic fiducial registration protocol was used during the procedure. All lesions were precisely localised and the biopsies could be taken from the representative part of the pathological mass. None of the patients developed aggravation of ocular symptoms after the procedure. The operative corridor as well as the size of orbital wall fenestration could be limited to a minimum. The accuracy of neuro-navigation remained high and stable during the entire procedure. The image-guided neuro-navigation system facilitated endoscopic localisation and biopsy of intraorbital tumors and contributed to the reduction of surgical trauma during the procedure. The technique was particularly useful in small, medially located, retrobulbar tumors and in unclear situations when the structure of the lesion resembled surrounding intraorbital tissue. (author)

Design of Endoscopic Capsule With Multiple Cameras.

Science.gov (United States)

Gu, Yingke; Xie, Xiang; Li, Guolin; Sun, Tianjia; Wang, Dan; Yin, Zheng; Zhang, Pengfei; Wang, Zhihua

2015-08-01

In order to reduce the miss rate of the wireless capsule endoscopy, in this paper, we propose a new system of the endoscopic capsule with multiple cameras. A master-slave architecture, including an efficient bus architecture and a four level clock management architecture, is applied for the Multiple Cameras Endoscopic Capsule (MCEC). For covering more area of the gastrointestinal tract wall with low power, multiple cameras with a smart image capture strategy, including movement sensitive control and camera selection, are used in the MCEC. To reduce the data transfer bandwidth and power consumption to prolong the MCEC's working life, a low complexity image compressor with PSNR 40.7 dB and compression rate 86% is implemented. A chipset is designed and implemented for the MCEC and a six cameras endoscopic capsule prototype is implemented by using the chipset. With the smart image capture strategy, the coverage rate of the MCEC prototype can achieve 98% and its power consumption is only about 7.1 mW.

Contribution of thermal infrared images on the understanding of the subsurface/atmosphere exchanges on Earth.

Science.gov (United States)

Lopez, Teodolina; Antoine, Raphaël; Baratoux, David; Rabinowicz, Michel

2017-04-01

High temporal resolution of space-based thermal infrared images (METEOSAT, MODIS) and the development of field thermal cameras have permitted the development of thermal remote sensing in Earth Sciences. Thermal images are influenced by many factors such as atmosphere, solar radiation, topography and physico-chemical properties of the surface. However, considering these limitations, we have discovered that thermal images can be used in order to better understand subsurface hydrology. In order to reduce as much as possible the impact of these perturbing factors, our approach combine 1) field observations and 2) numerical modelling of surface/subsurface thermal processes. Thermal images of the Piton de la Fournaise volcano (Réunion Island), acquired by hand, show that the Formica Leo inactive scoria cone and some fractures close to the Bory-Dolomieu caldera are always warmer, inducing a thermal difference with the surrounding of at least 5°C and a Self-Potential anomaly [1, 2]. Topography cannot explain this thermal behaviour, but Piton de la Fournaise is known as highly permeable. This fact allows the development of an air convection within the whole permeable structure volcanic edifice [2]. Cold air enters the base of the volcano, and exits warmer upslope, as the air is warmed by the geothermal flow [1,2]. Then, we have decided to understand the interaction between subsurface hydrogeological flows and the humidity in the atmosphere. In the Lake Chad basin, regions on both sides of Lake Chad present a different thermal behaviour during the diurnal cycle and between seasons [3]. We propose that this thermal behaviour can only be explained by lateral variations of the surface permeability that directly impact the process of evaporation/condensation cycle. These studies bring new highlights on the understanding of the exchanges between subsurface and the atmosphere, as the presence of a very permeable media and/or variations of the surface permeability may enhance or

MR imaging of colorectal carcinomas using an MR endoscopic coil

International Nuclear Information System (INIS)

Murano, Akihiko; Kido, Choichiro; Sasaki, Fumio; Nakamura, Tsuneya; Kobayashi, Semi; Katoh, Tomoyuki; Hirai, Takashi

1994-01-01

Diagnosis of the depth of wall invasion by rectal carcinoma using MR endoscopy was performed in ten resected specimens, including five rectal carcinomas, three colon carcinomas, two normal gastric wall. In addition, the gastric wall of a pig was examined. MR imaging was done with a 1.5-T Signa Advantage (GE Medical System) system, with the surface coil of the MR endoscope acting as the receiver coil. Five layers could be distinguished in the bowel wall: mucosa, submucosa and muscularis propria divided into circular muscle, longitudinal muscle and intervening connective tissue. Tumors had almost the same signal intensity as muscle. The MR images of colon carcinomas, rectal carcinomas, and extrinsically metastatic involvement of the sigmoid colon by rectal carcinoma all correlated well with the pathological findings. The normal structure of the gastric wall was similar to that of the colon. 3D-fast Spoiled Grass (SPGR) sequence has a fairly short scanning time. Thus, the possibility of precise clinical diagnosis by this method was suggested. (author)

Color reproduction and processing algorithm based on real-time mapping for endoscopic images.

Science.gov (United States)

Khan, Tareq H; Mohammed, Shahed K; Imtiaz, Mohammad S; Wahid, Khan A

2016-01-01

In this paper, we present a real-time preprocessing algorithm for image enhancement for endoscopic images. A novel dictionary based color mapping algorithm is used for reproducing the color information from a theme image. The theme image is selected from a nearby anatomical location. A database of color endoscopy image for different location is prepared for this purpose. The color map is dynamic as its contents change with the change of the theme image. This method is used on low contrast grayscale white light images and raw narrow band images to highlight the vascular and mucosa structures and to colorize the images. It can also be applied to enhance the tone of color images. The statistic visual representation and universal image quality measures show that the proposed method can highlight the mucosa structure compared to other methods. The color similarity has been verified using Delta E color difference, structure similarity index, mean structure similarity index and structure and hue similarity. The color enhancement was measured using color enhancement factor that shows considerable improvements. The proposed algorithm has low and linear time complexity, which results in higher execution speed than other related works.

New flexible endoscope for otologic application

Science.gov (United States)

Marchan, Mark L.

1993-07-01

Endoscopy has become an important procedure in many medical specialties. For the Otologist, however, space limitations within the ear have restricted development of endoscopic procedures. The desire for minimally invasive techniques in Otology has demonstrated itself through the work of numerous physicians who have performed procedures ranging from diagnostic inspection of the middle ear to viewing the interior of the cochlea. To assist in performing such endoscopic procedures, Xomed-Treace has developed a line of flexible fiberoptic endoscopes for use by the Otologist. These scopes combine illumination and imaging fiber bundles within a small diameter unit ranging in size from 0.8 mm to 1.2 mm. The 1.2 mm scope is produced with an angled, rigid stainless steel sheath. The 0.8 mm scope is flexible with the ability to articulate 120 degree(s) in one direction. The fiberscopes have been designed for the Otologist to produce a good resolution image while allowing ease of operation through ergonomics and consideration of the surgical anatomy.

Data Processing Methods for 3D Seismic Imaging of Subsurface Volcanoes: Applications to the Tarim Flood Basalt.

Science.gov (United States)

Wang, Lei; Tian, Wei; Shi, Yongmin

2017-08-07

The morphology and structure of plumbing systems can provide key information on the eruption rate and style of basalt lava fields. The most powerful way to study subsurface geo-bodies is to use industrial 3D reflection seismological imaging. However, strategies to image subsurface volcanoes are very different from that of oil and gas reservoirs. In this study, we process seismic data cubes from the Northern Tarim Basin, China, to illustrate how to visualize sills through opacity rendering techniques and how to image the conduits by time-slicing. In the first case, we isolated probes by the seismic horizons marking the contacts between sills and encasing strata, applying opacity rendering techniques to extract sills from the seismic cube. The resulting detailed sill morphology shows that the flow direction is from the dome center to the rim. In the second seismic cube, we use time-slices to image the conduits, which corresponds to marked discontinuities within the encasing rocks. A set of time-slices obtained at different depths show that the Tarim flood basalts erupted from central volcanoes, fed by separate pipe-like conduits.

Quantifying the dynamics of flow within a permeable bed using time-resolved endoscopic particle imaging velocimetry (EPIV)

Energy Technology Data Exchange (ETDEWEB)

Blois, G. [University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham (United Kingdom); University of Illinois, Department of Mechanical Science and Engineering, Urbana, IL (United States); Sambrook Smith, G.H.; Lead, J.R. [University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham (United Kingdom); Best, J.L. [University of Illinois, Departments of Geology, Geography, Mechanical Science and Engineering, and Ven Te Chow Hydrosystems Laboratory, Urbana, IL (United States); Hardy, R.J. [Durham University, Department of Geography, Science Laboratories, Durham (United Kingdom)

2012-07-15

This paper presents results of an experimental study investigating the mean and temporal evolution of flow within the pore space of a packed bed overlain by a free-surface flow. Data were collected by an endoscopic PIV (EPIV) technique. EPIV allows the instantaneous velocity field within the pore space to be quantified at a high spatio-temporal resolution, thus permitting investigation of the structure of turbulent subsurface flow produced by a high Reynolds number freestream flow (Re{sub s} in the range 9.8 x 10{sup 3}-9.7 x 10{sup 4}). Evolution of coherent flow structures within the pore space is shown to be driven by jet flow, with the interaction of this jet with the pore flow generating distinct coherent flow structures. The effects of freestream water depth, Reynolds and Froude numbers are investigated. (orig.)

Application of phase-contrast cine magnetic resonance imaging in endoscopic aqueductoplasty.

Science.gov (United States)

Chen, Guoqiang; Zheng, Jiaping; Xiao, Qing; Liu, Yunsheng

2013-06-01

The aim of this study was to evaluate the application of phase-contrast cine magnetic resonance imaging (MRI) in endoscopic aqueductoplasty (EA) for patients with obstructive hydrocephalus. The clinical diagnosis of hydrocephalus caused by aqueduct obstruction in 23 patients was confirmed by phase-contrast cine MRI examination. The patients were treated with EA and MRI was repeated during the follow-up. The cerebrospinal fluid (CSF) flow velocity in the aqueduct was measured to determine whether the aqueduct was obstructed. The results of phase-contrast cine MRI examinations indicated that there was no CSF flow in the aqueduct for all patients prior to surgery. Aqueductoplasty was successfully performed in all patients. The results of phase-contrast cine MRI examinations performed a week after surgery demonstrated an average CSF flow velocity of 4.74±1.77 cm/sec. During the follow-up, intracranial hypertension recurred in two patients in whom CSF flow was not observed in the aqueduct by the phase-contrast cine MRI scan. Aqueduct re-occlusion was revealed by an endoscopic exploration. By measuring the CSF flow velocity, phase-contrast cine MRI accurately identifies aqueduct obstruction. Cine MRI is a nontraumatic, simple and reliable method for determining whether the aqueduct is successfully opened following aqueductoplasty.

Detection of stiff nanoparticles within cellular structures by contact resonance atomic force microscopy subsurface nanomechanical imaging.

Science.gov (United States)

Reggente, Melania; Passeri, Daniele; Angeloni, Livia; Scaramuzzo, Francesca Anna; Barteri, Mario; De Angelis, Francesca; Persiconi, Irene; De Stefano, Maria Egle; Rossi, Marco

2017-05-04

Detecting stiff nanoparticles buried in soft biological matrices by atomic force microscopy (AFM) based techniques represents a new frontier in the field of scanning probe microscopies, originally developed as surface characterization methods. Here we report the detection of stiff (magnetic) nanoparticles (NPs) internalized in cells by using contact resonance AFM (CR-AFM) employed as a potentially non-destructive subsurface characterization tool. Magnetite (Fe 3 O 4 ) NPs were internalized in microglial cells from cerebral cortices of mouse embryos of 18 days by phagocytosis. Nanomechanical imaging of cells was performed by detecting the contact resonance frequencies (CRFs) of an AFM cantilever held in contact with the sample. Agglomerates of NPs internalized in cells were visualized on the basis of the local increase in the contact stiffness with respect to the surrounding biological matrix. A second AFM-based technique for nanomechanical imaging, i.e., HarmoniX™, as well as magnetic force microscopy and light microscopy were used to confirm the CR-AFM results. Thus, CR-AFM was demonstrated as a promising technique for subsurface imaging of nanomaterials in biological samples.

Hybrid model based unified scheme for endoscopic Cerenkov and radio-luminescence tomography: Simulation demonstration

Science.gov (United States)

Wang, Lin; Cao, Xin; Ren, Qingyun; Chen, Xueli; He, Xiaowei

2018-05-01

Cerenkov luminescence imaging (CLI) is an imaging method that uses an optical imaging scheme to probe a radioactive tracer. Application of CLI with clinically approved radioactive tracers has opened an opportunity for translating optical imaging from preclinical to clinical applications. Such translation was further improved by developing an endoscopic CLI system. However, two-dimensional endoscopic imaging cannot identify accurate depth and obtain quantitative information. Here, we present an imaging scheme to retrieve the depth and quantitative information from endoscopic Cerenkov luminescence tomography, which can also be applied for endoscopic radio-luminescence tomography. In the scheme, we first constructed a physical model for image collection, and then a mathematical model for characterizing the luminescent light propagation from tracer to the endoscopic detector. The mathematical model is a hybrid light transport model combined with the 3rd order simplified spherical harmonics approximation, diffusion, and radiosity equations to warrant accuracy and speed. The mathematical model integrates finite element discretization, regularization, and primal-dual interior-point optimization to retrieve the depth and the quantitative information of the tracer. A heterogeneous-geometry-based numerical simulation was used to explore the feasibility of the unified scheme, which demonstrated that it can provide a satisfactory balance between imaging accuracy and computational burden.

3D seismic imaging of the subsurface for underground construction and drilling

International Nuclear Information System (INIS)

Juhlin, Christopher

2014-01-01

3D seismic imaging of underground structure has been carried out in various parts of the world for various purposes. Examples shown below were introduced in the presentation. - CO 2 storage in Ketzin, Germany; - Mine planning at the Millennium Uranium Deposit in Canada; - Planned Forsmark spent nuclear fuel repository in Sweden; - Exploring the Scandinavian Mountain Belt by Deep Drilling: the COSC drilling project in Sweden. The author explained that seismic methods provide the highest resolution images (5-10 m) of deeper (1-5 km) sub-surfaces in the sedimentary environment, but further improvement is required in crystalline rock environments, and the integration of geology, geophysics, and drilling will provide an optimal interpretation. (author)

Essential pre-treatment imaging examinations in patients with endoscopically-diagnosed early gastric cancer

Directory of Open Access Journals (Sweden)

Tokunaga Mari

2010-06-01

Full Text Available Abstract Background There have been no reports discussing which imaging procedures are truly necessary before treatment of endoscopically-diagnosed early gastric cancer (eEGC. The aim of this pilot study was to show which imaging examinations are essential to select indicated treatment or appropriate strategy in patients with eEGC. Methods In 140 consecutive patients (95 men, 45 women; age, 66.4 +/- 11.3 years [mean +/- standard deviation], range, 33-90 with eEGC which were diagnosed during two years, the pre-treatment results of ultrasonography (US and contrast-enhanced computed tomography (CT of the abdomen, barium enema (BE and chest radiography (CR were retrospectively reviewed. Useful findings that might affect indication or strategy were evaluated. Results US demonstrated useful findings in 13 of 140 patients (9.3%: biliary tract stones (n = 11 and other malignant tumors (n = 2. Only one useful finding was demonstrated on CT (pancreatic intraductal papillary mucinous tumor but not on US (0.7%; 95% confidential interval [CI], 2.1%. BE demonstrated colorectal carcinomas in six patients and polyps in 10 patients, altering treatment strategy (11.4%; 95%CI, 6.1-16.7%. Of these, only two colorectal carcinomas were detected on CT. CR showed three relevant findings (2.1%: pulmonary carcinoma (n = 1 and cardiomegaly (n = 2. Seventy-nine patients (56% were treated surgically and 56 patients were treated by endoscopic intervention. The remaining five patients received no treatment due to various reasons. Conclusions US, BE and CR may be essential as pre-treatment imaging examinations because they occasionally detect findings which affect treatment indication and strategy, although abdominal contrast-enhanced CT rarely provide additional information.

Integrated biophotonics in endoscopic oncology

Science.gov (United States)

Muguruma, Naoki; DaCosta, Ralph S.; Wilson, Brian C.; Marcon, Norman E.

2009-02-01

Gastrointestinal endoscopy has made great progress during last decade. Diagnostic accuracy can be enhanced by better training, improved dye-contrast techniques method, and the development of new image processing technologies. However, diagnosis using conventional endoscopy with white-light optical imaging is essentially limited by being based on morphological changes and/or visual attribution: hue, saturation and intensity, interpretation of which depends on the endoscopist's eye and brain. In microlesions in the gastrointestinal tract, we still rely ultimately on the histopathological diagnosis from biopsy specimens. Autofluorescence imaging system has been applied for lesions which have been difficult to morphologically recognize or are indistinct with conventional endoscope, and this approach has potential application for the diagnosis of dysplastic lesions and early cancers in the gastrointestinal tract, supplementing the information from white light endoscopy. This system has an advantage that it needs no administration of a photosensitive agent, making it suitable as a screening method for the early detection of neoplastic tissues. Narrow band imaging (NBI) is a novel endoscopic technique which can distinguish neoplastic and non-neoplastic lesions without chromoendoscopy. Magnifying endoscopy in combination with NBI has an obvious advantage, namely analysis of the epithelial pit pattern and the vascular network. This new technique allows a detailed visualization in early neoplastic lesions of esophagus, stomach and colon. However, problems remain; how to combine these technologies in an optimum diagnostic strategy, how to apply them into the algorithm for therapeutic decision-making, and how to standardize several classifications surrounding them. 'Molecular imaging' is a concept representing the most novel imaging methods in medicine, although the definition of the word is still controversial. In the field of gastrointestinal endoscopy, the future of

Low-complexity video encoding method for wireless image transmission in capsule endoscope.

Science.gov (United States)

Takizawa, Kenichi; Hamaguchi, Kiyoshi

2010-01-01

This paper presents a low-complexity video encoding method applicable for wireless image transmission in capsule endoscopes. This encoding method is based on Wyner-Ziv theory, in which side information available at a transmitter is treated as side information at its receiver. Therefore complex processes in video encoding, such as estimation of the motion vector, are moved to the receiver side, which has a larger-capacity battery. As a result, the encoding process is only to decimate coded original data through channel coding. We provide a performance evaluation for a low-density parity check (LDPC) coding method in the AWGN channel.

Electrical imaging of subsurface nanoparticle propagation for in-situ groundwater remediation

Science.gov (United States)

Flores Orozco, Adrián; Gallistl, Jakob; Schmid, Doris; Micic Batka, Vesna; Bücker, Matthias; Hofmann, Thilo

2017-04-01

Application of nanoparticles has emerged as a promising in situ remediation technology for the remediation of contaminated groundwater, particularly for areas difficult to access by other remediation techniques. The performance of nanoparticle injections, as a foremost step within this technology, is usually assessed through the geochemical analysis of soil and groundwater samples. This approach is not well suited for a real-time monitoring, and often suffers from a poor spatio-temporal resolution and only provides information from areas close to the sampling points. To overcome these limitations we propose the application of non-invasive Induced Polarization (IP) imaging, a geophysical method that provides information on the electrical properties of the subsurface. The analysis of temporal changes in the electrical images allows tracking the propagation of the injected nanoparticle suspension and detection of the induced bio-geochemical changes in the subsurface. Here, we present IP monitoring results for data collected during the injection of Nano-Goethite particles (NGP) used for simulation of biodegradation of a BTEX plume (i.e., benzene, toluene, ethylbenzene, and xylene) at the Spolchemie II site, CZ. Frequency-domain IP measurements were collected parallel to the groundwater flow direction and centred on the NGP injection point. Pre-injection imaging results revealed high electrical conductivities (> 10 S/m) and negligible polarization effects in the BTEX-contaminated part of the saturated zone (below 5 m depth). The apparently contradictory observation - BTEX compounds are poor electrical conductors - can be explained by the release of carbonic acids (a metabolic by-product of the biodegradation of hydrocarbons), which leads to an increase of the electrical conductivity. Post-injection images revealed a significant decrease (> 50%) of the electrical conductivity, with even larger changes in the proximity of the injection points, most likely due to the

In vivo endoscopic multi-beam optical coherence tomography

Energy Technology Data Exchange (ETDEWEB)

Standish, Beau A; Mariampillai, Adrian; Munce, Nigel R; Leung, Michael K K; Vitkin, I Alex [Deptartment of Medical Biophysics, University of Toronto, Toronto (Canada); Lee, Kenneth K C; Yang, Victor X D [Ontario Cancer Institute/University Health Network, Toronto (Canada)], E-mail: standish@ee.ryerson.ca

2010-02-07

A multichannel optical coherence tomography (multi-beam OCT) system and an in vivo endoscopic imaging probe were developed using a swept-source OCT system. The distal optics were micro-machined to produce a high numerical aperture, multi-focus fibre optic array. This combination resulted in a transverse design resolution of <10 {mu}m full width half maximum (FWHM) throughout the entire imaging range, while also increasing the signal intensity within the focus of the individual channels. The system was used in a pre-clinical rabbit study to acquire in vivo structural images of the colon and ex vivo images of the oesophagus and trachea. A good correlation between the structural multi-beam OCT images and H and E histology was achieved, demonstrating the feasibility of this high-resolution system and its potential for in vivo human endoscopic imaging.

In vivo endoscopic multi-beam optical coherence tomography

International Nuclear Information System (INIS)

Standish, Beau A; Mariampillai, Adrian; Munce, Nigel R; Leung, Michael K K; Vitkin, I Alex; Lee, Kenneth K C; Yang, Victor X D

2010-01-01

A multichannel optical coherence tomography (multi-beam OCT) system and an in vivo endoscopic imaging probe were developed using a swept-source OCT system. The distal optics were micro-machined to produce a high numerical aperture, multi-focus fibre optic array. This combination resulted in a transverse design resolution of <10 μm full width half maximum (FWHM) throughout the entire imaging range, while also increasing the signal intensity within the focus of the individual channels. The system was used in a pre-clinical rabbit study to acquire in vivo structural images of the colon and ex vivo images of the oesophagus and trachea. A good correlation between the structural multi-beam OCT images and H and E histology was achieved, demonstrating the feasibility of this high-resolution system and its potential for in vivo human endoscopic imaging.

Ultrasound-assisted endoscopic partial plantar fascia release.

Science.gov (United States)

Ohuchi, Hiroshi; Ichikawa, Ken; Shinga, Kotaro; Hattori, Soichi; Yamada, Shin; Takahashi, Kazuhisa

2013-01-01

Various surgical treatment procedures for plantar fasciitis, such as open surgery, percutaneous release, and endoscopic surgery, exist. Skin trouble, nerve disturbance, infection, and persistent pain associated with prolonged recovery time are complications of open surgery. Endoscopic partial plantar fascia release offers the surgeon clear visualization of the anatomy at the surgical site. However, the primary medial portal and portal tract used for this technique have been shown to be in close proximity to the posterior tibial nerves and their branches, and there is always the risk of nerve damage by introducing the endoscope deep to the plantar fascia. By performing endoscopic partial plantar fascia release under ultrasound assistance, we could dynamically visualize the direction of the endoscope and instrument introduction, thus preventing nerve damage from inadvertent insertion deep to the fascia. Full-thickness release of the plantar fascia at the ideal position could also be confirmed under ultrasound imaging. We discuss the technique for this new procedure.

Feasibility study of novel endoscopic Cerenkov luminescence imaging system in detecting and quantifying gastrointestinal disease: first human results

International Nuclear Information System (INIS)

Hu, Hao; Li, Shujun; Yao, Liping; Liang, Jie; Nie, Yongzhan; Wu, Kaichun; Cao, Xin; Lin, Yenan; Liu, Muhan; Liang, Jimin; Chen, Xueli; Kang, Fei; Wang, Jing; Wang, Min

2015-01-01

Cerenkov luminescence imaging (CLI) provides potential to use clinical radiotracers for optical imaging. The goal of this study was to present a newly developed endoscopic CLI (ECLI) system and illustrate its feasibility and potential in distinguishing and quantifying cancerous lesions of the GI tract. The ECLI system was established by integrating an electron-multiplying charge-coupled device camera with a flexible fibre endoscope. Phantom experiments and animal studies were conducted to test and illustrate the system in detecting and quantifying the presence of radionuclide in vitro and in vivo. A pilot clinical study was performed to evaluate our system in clinical settings. Phantom and mice experiments demonstrated its ability to acquire both the luminescent and photographic images with high accuracy. Linear quantitative relationships were also obtained when comparing the ECLI radiance with the radiotracer activity (r 2 = 0.9779) and traditional CLI values (r 2 = 0.9025). Imaging of patients revealed the potential of ECLI in the identification and quantification of cancerous tissue from normal, which showed good consistence with the clinical PET examination. The new ECLI system shows good consistence with the clinical PET examination and has great potential for clinical translation and in aiding detection of the GI tract disease. (orig.)

Feasibility study of novel endoscopic Cerenkov luminescence imaging system in detecting and quantifying gastrointestinal disease: first human results

Energy Technology Data Exchange (ETDEWEB)

Hu, Hao; Li, Shujun; Yao, Liping; Liang, Jie; Nie, Yongzhan; Wu, Kaichun [Fourth Military Medical University, State Key Laboratory of Cancer Biology, Department of Digestive Diseases, Xijing Hospital, Xi' an (China); Cao, Xin; Lin, Yenan; Liu, Muhan; Liang, Jimin; Chen, Xueli [Xidian University, School of Life Science and Technology, Xi' an (China); Kang, Fei; Wang, Jing [Fourth Military Medical University, Department of Nuclear Medicine, Xijing Hospital, Xi' an (China); Wang, Min [Xi' an Children' s Hospital, Department of Gastroenterology, Xi' an (China)

2015-06-01

Cerenkov luminescence imaging (CLI) provides potential to use clinical radiotracers for optical imaging. The goal of this study was to present a newly developed endoscopic CLI (ECLI) system and illustrate its feasibility and potential in distinguishing and quantifying cancerous lesions of the GI tract. The ECLI system was established by integrating an electron-multiplying charge-coupled device camera with a flexible fibre endoscope. Phantom experiments and animal studies were conducted to test and illustrate the system in detecting and quantifying the presence of radionuclide in vitro and in vivo. A pilot clinical study was performed to evaluate our system in clinical settings. Phantom and mice experiments demonstrated its ability to acquire both the luminescent and photographic images with high accuracy. Linear quantitative relationships were also obtained when comparing the ECLI radiance with the radiotracer activity (r{sup 2} = 0.9779) and traditional CLI values (r{sup 2} = 0.9025). Imaging of patients revealed the potential of ECLI in the identification and quantification of cancerous tissue from normal, which showed good consistence with the clinical PET examination. The new ECLI system shows good consistence with the clinical PET examination and has great potential for clinical translation and in aiding detection of the GI tract disease. (orig.)

Geophysical data fusion for subsurface imaging

International Nuclear Information System (INIS)

Blohm, M.; Hatch, W.E.; Hoekstra, P.; Porter, D.W.

1994-01-01

Effective site characterization requires that many relevant geologic, hydrogeologic and biological properties of the subsurface be evaluated. A parameter that often directly influences chemical processes, ground water flow, contaminant transport, and biological activities is the lateral and vertical distribution of clays. The objective of the research an development under this contract is to improve non-invasive methods for detecting clay lenses. The percentage of clays in soils influences most physical properties that have an impact on environmental restoration and waste management. For example, the percentage of clays determine hydraulic permeability and the rate of contaminant migration, absorption of radioactive elements, and interaction with organic compounds. Therefore, improvements in non-invasive mapping of clays in the subsurface will result in better: characterization of contaminated sites, prediction of pathways of contaminant migration, assessment of risk of contaminants to public health if contaminants reach water supplies, design of remedial action and evaluation of alternative action

Extracting subsurface fingerprints using optical coherence tomography

CSIR Research Space (South Africa)

Akhoury, SS

2015-02-01

Full Text Available Subsurface Fingerprints using Optical Coherence Tomography Sharat Saurabh Akhoury, Luke Nicholas Darlow Modelling and Digital Science, Council for Scientific and Industrial Research, Pretoria, South Africa Abstract Physiologists have found... approach to extract the subsurface fingerprint representation using a high-resolution imaging technology known as Optical Coherence Tomography (OCT). ...

Development of image-guided operation system having integrated information of the patient for procedure of endoscopic surgery of digestive tracts

International Nuclear Information System (INIS)

Hattori, Asaki; Suzuki, Naoki; Tanoue, Kazuo; Ieiri, Satoshi; Konishi, Kozo; Tomikawa, Morimasa; Kenmotsu, Hajime; Hashizume, Makoto

2010-01-01

This study reports the development of patient's integrated information-displaying system at image-guided, robotic peroral endoscopic operation of digestive tracts as well as the actual operative field for the operator not to look aside. The peroral endoscope has, at its top, a magnetic position sensor and 2 robotic manipulative forceps at right and left side to navigate the surgery through following 3 windows of superimposing display: the inner peritoneal 3D structure of the real operative field reconstructed from preoperative CT and MR images by volume rendering, presentation of the robot top tip in the structure above and in the preoperative CT or MR image as an ordinary navigation. Furthermore, the robot has a function to measure softness of its grabbing tissue which is displayed in the corresponding right and left superimposing windows, and signs like the real-time blood pressure and heart rate are also given in another window. All of the patient's integrated information-displaying can be handled at will during the operation. Improvement of user interface and of navigation display is further to be conducted. (T.T.)

An algorithm for improving the quality of structural images of turbid media in endoscopic optical coherence tomography

Science.gov (United States)

Potlov, A. Yu.; Frolov, S. V.; Proskurin, S. G.

2018-04-01

High-quality OCT structural images reconstruction algorithm for endoscopic optical coherence tomography of biological tissue is described. The key features of the presented algorithm are: (1) raster scanning and averaging of adjacent Ascans and pixels; (2) speckle level minimization. The described algorithm can be used in the gastroenterology, urology, gynecology, otorhinolaryngology for mucous membranes and skin diagnostics in vivo and in situ.

Sub-surface defects detection of by using active thermography and advanced image edge detection

International Nuclear Information System (INIS)

Tse, Peter W.; Wang, Gaochao

2017-01-01

Active or pulsed thermography is a popular non-destructive testing (NDT) tool for inspecting the integrity and anomaly of industrial equipment. One of the recent research trends in using active thermography is to automate the process in detecting hidden defects. As of today, human effort has still been using to adjust the temperature intensity of the thermo camera in order to visually observe the difference in cooling rates caused by a normal target as compared to that by a sub-surface crack exists inside the target. To avoid the tedious human-visual inspection and minimize human induced error, this paper reports the design of an automatic method that is capable of detecting subsurface defects. The method used the technique of active thermography, edge detection in machine vision and smart algorithm. An infrared thermo-camera was used to capture a series of temporal pictures after slightly heating up the inspected target by flash lamps. Then the Canny edge detector was employed to automatically extract the defect related images from the captured pictures. The captured temporal pictures were preprocessed by a packet of Canny edge detector and then a smart algorithm was used to reconstruct the whole sequences of image signals. During the processes, noise and irrelevant backgrounds exist in the pictures were removed. Consequently, the contrast of the edges of defective areas had been highlighted. The designed automatic method was verified by real pipe specimens that contains sub-surface cracks. After applying such smart method, the edges of cracks can be revealed visually without the need of using manual adjustment on the setting of thermo-camera. With the help of this automatic method, the tedious process in manually adjusting the colour contract and the pixel intensity in order to reveal defects can be avoided. (paper)

Wall Painting Investigation by Means of Non-invasive Terahertz Time-Domain Imaging (THz-TDI): Inspection of Subsurface Structures Buried in Historical Plasters

Science.gov (United States)

Dandolo, Corinna Ludovica Koch; Jepsen, Peter Uhd

2016-02-01

Characterization of subsurface features of wall paintings is important in conservation and technical art history as well as in building archaeology and architecture fields. In this study, an area of the apsidal wall painting of Nebbelunde Church (Rødby, Denmark) has been investigated by means of terahertz time-domain imaging (THz-TDI). Subsurface structures have been detected at different depths inside the lime-based plaster of the wall painting until approximately 1 cm from the surface. The surface morphology of the buried structures has been 3D imaged in detail, providing a substantial contribution in their characterization.

Endoscopic mode for three-dimensional CT display of normal and pathologic laryngeal structures

International Nuclear Information System (INIS)

Sanuki, Tetsuji; Hyodo, Masamitsu; Yumoto, Eiji; Yasuhara, Yoshifumi; Ochi, Takashi

1997-01-01

The recent development of helical (spiral) computed tomography allows collection of volumetric data to obtain high quality three-dimensional (3D) reconstructed images. The authors applied the 3D CT endoscopic imaging technique to asses normal and pathologic laryngeal structures. The latter included trauma, vocal fold atrophy, cancer of the larynx and recurrent nerve palsy. This technique was able to show normal laryngeal structures and characteristic findings of each pathology. The 3D CT endoscopic images can be rotated around any axis, allowing optimal depiction of pathologic lesion. The use of 3D CT endoscopic technique provides the display of the location and extent of pathology and affords accurate therapeutic planning. (author)

Investigating the Surface and Subsurface in Karstic Regions – Terrestrial Laser Scanning versus Low-Altitude Airborne Imaging and the Combination with Geophysical Prospecting

Directory of Open Access Journals (Sweden)

Nora Tilly

2017-08-01

Full Text Available Combining measurements of the surface and subsurface is a promising approach to understand the origin and current changes of karstic forms since subterraneous processes are often the initial driving force. A karst depression in south-west Germany was investigated in a comprehensive campaign with remote sensing and geophysical prospecting. This contribution has two objectives: firstly, comparing terrestrial laser scanning (TLS and low-altitude airborne imaging from an unmanned aerial vehicle (UAV regarding their performance in capturing the surface. Secondly, establishing a suitable way of combining this 3D surface data with data from the subsurface, derived by geophysical prospecting. Both remote sensing approaches performed satisfying and the established digital elevation models (DEMs differ only slightly. These minor discrepancies result essentially from the different viewing geometries and post-processing concepts, for example whether the vegetation was removed or not. Validation analyses against high-accurate DGPS-derived point data sets revealed slightly better results for the DEMTLS with a mean absolute difference of 0.03 m to 0.05 m and a standard deviation of 0.03 m to 0.07 m (DEMUAV: mean absolute difference: 0.11 m to 0.13 m; standard deviation: 0.09 m to 0.11 m. The 3D surface data and 2D image of the vertical cross section through the subsurface along a geophysical profile were combined in block diagrams. The data sets fit very well and give a first impression of the connection between surface and subsurface structures. Since capturing the subsurface with this method is limited to 2D and the data acquisition is quite time consuming, further investigations are necessary for reliable statements about subterraneous structures, how these may induce surface changes, and the origin of this karst depression. Moreover, geophysical prospecting can only produce a suspected image of the subsurface since the apparent resistivity is measured

Combining endoscopes with PIV and digital holography for the study of vessel model mechanics

International Nuclear Information System (INIS)

Arévalo, Laura; Palero, Virginia; Andrés, Nieves; Arroyo, M P; Lobera, Julia

2015-01-01

In this work traditional fluid and solid mechanics measurement techniques have been combined with endoscopes for the study of blood vessel models’ mechanical properties. Endoscopes have been used as the imaging part of a high-speed PIV system to obtain the velocity field in a vessel model immersed in a container with a refractive index-matching liquid. In this way, we take advantage of the fact that the endoscope tip can be immersed in liquid. Endoscopes have also been used as the imaging and illuminating part of a digital holographic set-up for wall deformation measurement. The novelty of this work is that only one endoscope was used for illuminating and observing the vessel model, using the endoscope’s own illuminating system as the illumination source. The performance of endoscopes in different vessel models has been tested. The results of flow velocity and wall deformation in the different blood vessel models are presented. (paper)

Active infrared thermography for visualizing subsurface micro voids in an epoxy molding compound

Energy Technology Data Exchange (ETDEWEB)

Yang, Ji Yeol [Test and Package Center, Samsung Electronics, Asan(Korea, Republic of); Hwang, Soon Kyu; Choi, Jae Mook; Sohn, Hoon [Dept. of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2017-04-15

This paper presents an automated subsurface micro void detection technique based on pulsed infrared thermography for inspecting epoxy molding compounds (EMC) used in electronic device packaging. Subsurface micro voids are first detected and visualized by extracting a lock-in amplitude image from raw thermal images. Binary imaging follows to achieve better visualization of subsurface micro voids. A median filter is then applied for removing sparse noise components. The performance of the proposed technique is tested using 36 EMC samples, which have subsurface (below 150 μm ~ 300 μm from the inspection surface) micro voids (150 μm ~ 300 μm in diameter). The experimental results show that the subsurface micro voids can be successfully detected without causing any damage to the EMC samples, making it suitable for automated online inspection.

VISUALIZATION OF REGISTERED SUBSURFACE ANATOMY

DEFF Research Database (Denmark)

2010-01-01

A system and method for visualization of subsurface anatomy includes obtaining a first image from a first camera and a second image from a second camera or a second channel of the first camera, where the first and second images contain shared anatomical structures. The second camera and the secon....... A visual interface displays the registered visualization of the first and second images. The system and method are particularly useful for imaging during minimally invasive surgery, such as robotic surgery....

Full optical model of micro-endoscope with optical coherence microscopy, multiphoton microscopy and visible capabilities

Science.gov (United States)

Vega, David; Kiekens, Kelli C.; Syson, Nikolas C.; Romano, Gabriella; Baker, Tressa; Barton, Jennifer K.

2018-02-01

While Optical Coherence Microscopy (OCM), Multiphoton Microscopy (MPM), and narrowband imaging are powerful imaging techniques that can be used to detect cancer, each imaging technique has limitations when used by itself. Combining them into an endoscope to work in synergy can help achieve high sensitivity and specificity for diagnosis at the point of care. Such complex endoscopes have an elevated risk of failure, and performing proper modelling ensures functionality and minimizes risk. We present full 2D and 3D models of a multimodality optical micro-endoscope to provide real-time detection of carcinomas, called a salpingoscope. The models evaluate the endoscope illumination and light collection capabilities of various modalities. The design features two optical paths with different numerical apertures (NA) through a single lens system with a scanning optical fiber. The dual path is achieved using dichroic coatings embedded in a triplet. A high NA optical path is designed to perform OCM and MPM while a low NA optical path is designed for the visible spectrum to navigate the endoscope to areas of interest and narrowband imaging. Different tests such as the reflectance profile of homogeneous epithelial tissue were performed to adjust the models properly. Light collection models for the different modalities were created and tested for efficiency. While it is challenging to evaluate the efficiency of multimodality endoscopes, the models ensure that the system is design for the expected light collection levels to provide detectable signal to work for the intended imaging.

High-quality endoscope reprocessing decreases endoscope contamination.

Science.gov (United States)

Decristoforo, P; Kaltseis, J; Fritz, A; Edlinger, M; Posch, W; Wilflingseder, D; Lass-Flörl, C; Orth-Höller, D

2018-02-24

Several outbreaks of severe infections due to contamination of gastrointestinal (GI) endoscopes, mainly duodenoscopes, have been described. The rate of microbial endoscope contamination varies dramatically in literature. The aim of this multicentre prospective study was to evaluate the hygiene quality of endoscopes and automated endoscope reprocessors (AERs) in Tyrol/Austria. In 2015 and 2016, a total of 463 GI endoscopes and 105 AERs from 29 endoscopy centres were analysed by a routine (R) and a combined routine and advanced (CRA) sampling procedure and investigated for microbial contamination by culture-based and molecular-based analyses. The contamination rate of GI endoscopes was 1.3%-4.6% according to the national guideline, suggesting that 1.3-4.6 patients out of 100 could have had contacts with hygiene-relevant microorganisms through an endoscopic intervention. Comparison of R and CRA sampling showed 1.8% of R versus 4.6% of CRA failing the acceptance criteria in phase I and 1.3% of R versus 3.0% of CRA samples failing in phase II. The most commonly identified indicator organism was Pseudomonas spp., mainly Pseudomonas oleovorans. None of the tested viruses were detected in 40 samples. While AERs in phase I failed (n = 9, 17.6%) mainly due to technical faults, phase II revealed lapses (n = 6, 11.5%) only on account of microbial contamination of the last rinsing water, mainly with Pseudomonas spp. In the present study the contamination rate of endoscopes was low compared with results from other European countries, possibly due to the high quality of endoscope reprocessing, drying and storage. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Capabilities of seismic and georadar 2D/3D imaging of shallow subsurface of transport route using the Seismobile system

Science.gov (United States)

Pilecki, Zenon; Isakow, Zbigniew; Czarny, Rafał; Pilecka, Elżbieta; Harba, Paulina; Barnaś, Maciej

2017-08-01

In this work, the capabilities of the Seismobile system for shallow subsurface imaging of transport routes, such as roads, railways, and airport runways, in different geological conditions were presented. The Seismobile system combines the advantages of seismic profiling using landstreamer and georadar (GPR) profiling. It consists of up to four seismic measuring lines and carriage with a suspended GPR antenna. Shallow subsurface recognition may be achieved to a maximum width of 10.5 m for a distance of 3.5 m between the measurement lines. GPR measurement is performed in the axis of the construction. Seismobile allows the measurement time, labour and costs to be reduced due to easy technique of its installation, remote data transmission from geophones to accompanying measuring modules, automated location of the system based on GPS and a highly automated method of seismic wave excitation. In this paper, the results of field tests carried out in different geological conditions were presented. The methodologies of acquisition, processing and interpretation of seismic and GPR measurements were broadly described. Seismograms and its spectrum registered by Seismobile system were compared to the ones registered by Geode seismograph of Geometrix. Seismic data processing and interpretation software allows for the obtaining of 2D/3D models of P- and S-wave velocities. Combined seismic and GPR results achieved sufficient imaging of shallow subsurface to a depth of over a dozen metres. The obtained geophysical information correlated with geological information from the boreholes with good quality. The results of performed tests proved the efficiency of the Seismobile system in seismic and GPR imaging of a shallow subsurface of transport routes under compound conditions.

Benign submucosal lesions of the stomach and duodenum: Imaging characteristics with endoscopic and pathologic correlation

International Nuclear Information System (INIS)

Oh, Jong Young; Nam, Kyung Jin; Choi, Jong Cheol; Cho, Jin Han; Yoon, Seong Kuk; Choi, Sun Seob; Kwon, Hee Jin; Yoon, Jung Hee; Kim, Su Jin

2008-01-01

Benign submucosal lesions of the stomach and duodenum are occasionally encountered during endoscopy. But endoscopy has its limitations in the diagnosis and differentiation of these lesions, because submucosal lesions are often difficult to visualize at endoscopy due to minimal change of the overlying mucosa. Furthermore, endoscopic biopsy may not always yield adequate tissue for diagnosis due to the submucosal location of the lesions. For this reason, the role of radiologic imaging is important in the diagnosis of submucosal lesions of the stomach and duodenum. Recent advances in computed tomography (CT) and sonographic technology are helpful in narrowing the differential diagnosis of gastroduodenal submucosal lesions. In contrast to endoscopy and barium studies, CT or ultrasonography (US) provides information about both the gastric wall and the extragastric extent of the disease. Arterial phase contrast enhanced CT enables us to discriminate a mass of submucosal from that of a mucosal origin in the differential diagnosis of gastric or duodenal lesions. Although endoscopic sonography has been considered the better modality in the diagnosis of gastroduodenal submucosal lesions, transabdominal sonography can still be an alternative method to endoscopic sonography in assessing of the origin and character of the submucosal lesions. Some gastroduodenal submucosal lesions have similar radiologic findings that make differentiation difficult. But despite overlaps in radiologic findings, some lesions have characteristic radiologic features that may suggest a specific diagnosis. Knowledge of the differential diagnosis of benign submucosal lesions in the stomach and duodenum may promote correct diagnosis and appropriate treatment

Endoscopic retrograde cholangiopancreatography and endoscopic ...

African Journals Online (AJOL)

An approach to suspected gallstone pancreatitis'based on endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy (ES) was adopted in 1976 and was followed in 29 patients. ERCp became the routine method of early biliary tract assessment when gallstone pancreatitis was suspected on ...

Endoscopic and keyhole endoscope-assisted neurosurgical approaches: a qualitative survey on technical challenges and technological solutions.

Science.gov (United States)

Marcus, Hani J; Cundy, Thomas P; Hughes-Hallett, Archie; Yang, Guang-Zhong; Darzi, Ara; Nandi, Dipankar

2014-10-01

The literature reflects a resurgence of interest in endoscopic and keyhole endoscope-assisted neurosurgical approaches as alternatives to conventional microsurgical approaches in carefully selected cases. The aim of this study was to assess the technical challenges of neuroendoscopy, and the scope for technological innovations to overcome these barriers. All full members of the Society of British Neurosurgeons (SBNS) were electronically invited to participate in an online survey. The open-ended structured survey asked three questions; firstly, whether the surgeon presently utilises or has experience with endoscopic or endoscope-assisted approaches; secondly, what they consider to be the major technical barriers to adopting such approaches; and thirdly, what technological advances they foresee improving safety and efficacy in the field. Responses were subjected to a qualitative research method of multi-rater emergent theme analysis. Three clear themes emerged: 1) surgical approach and better integration with image-guidance systems (20%), 2) intra-operative visualisation and improvements in neuroendoscopy (49%), and 3) surgical manipulation and improvements in instruments (74%). The analysis of responses to our open-ended survey revealed that although opinion was varied three major themes could be identified. Emerging technological advances such as augmented reality, high-definition stereo-endoscopy, and robotic joint-wristed instruments may help overcome the technical difficulties associated with neuroendoscopic approaches. Results of this qualitative survey provide consensus amongst the technology end-user community such that unambiguous goals and priorities may be defined. Systems integrating these advances could improve the safety and efficacy of endoscopic and endoscope-assisted neurosurgical approaches.

Comparison of microscopic and endoscopic view of the internal acoustic meatus: A cadaveric study.

Science.gov (United States)

Montibeller, Guilherme Ramina; Hendrix, Philipp; Fries, Fabian N; Becker, Kurt W; Oertel, Joachim

2018-04-01

The endoscope is thought to provide an improved exposure of the internal acoustic meatus after retrosigmoid craniotomy for microsurgical resection of intrameatal tumors. The aim of this study is to quantify the differences in internal acoustic meatus (IAM) exposure comparing microscopic and endoscopic visualization. A retrosigmoid approach was performed on 5 cadaver heads. A millimeter gauge was introduced into the internal acoustic meatus, and examinations with a surgical microscope and 0°, 30° and 70° rigid endoscopes were performed. The extent of IAM depth visualized with the microscope and the different angled endoscopes were analyzed. The microscopic view allowed an average IAM depth visualization of 2.8 mm. The endoscope allowed an improved exposure of IAM in all cases. The 0°, 30° and 70° endoscopes permitted an exposure that was respectively 96% (5.5 mm), 139% (6.7 mm) and 200% (8.4 mm) more lateral than the microscopic view. Angled optics, however, provided an image distortion, specifically the 70° endoscope. The endoscope provides a superior visualization of the IAM compared to the microscope when using a retrosigmoid approach. The 30° endoscope represented an ideal compromise of superior visualization with marginal image distortion. Additional implementation of the endoscope into microsurgery of intrameatal tumors likely facilitates complete tumor removal and might spare facial and vestibulocochlear function. Clin. Anat. 31:398-403, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

New endoscope shaft for endoscopic transsphenoidal pituitary surgery.

NARCIS (Netherlands)

Lindert, E.J. van; Grotenhuis, J.A.

2005-01-01

OBJECTIVE: To describe a new endoscope shaft developed for suction-aspiration during endoscopic transsphenoidal pituitary surgery. METHODS: A custom-made shaft for a Wolf endoscope (Richard Wolf GmbH, Knittlingen, Germany) was developed with a height of 10 mm and a width of 5 mm, allowing an

A Panoramic Wireless Endoscope System Design for the Application of Minimally Invasive Surgery

Directory of Open Access Journals (Sweden)

Chun-Hsiang Peng

2014-05-01

Full Text Available Minimally Invasive Surgery (MIS is the current trend in surgery. Compared to traditional surgery, MIS can substantially decrease recovery time and expenses needed by patients after surgeries, reduce pain during surgical procedures, and is highly regarded by physicians and patients. An endoscope is widely used in the diagnosis and treatments of various medical disciplines, such as hysteroscopy, laparoscopy, and colonoscopy, and have been adopted by many branches of medicine. However, the limited image field of MIS is often the most difficult obstacles faced by surgeons and medical students, especially to less experienced physicians and difficult surgical procedures; the limited field of view of endoscopic imaging does not provide a whole picture of the surgery area, making the procedures difficult and full of uncertainty. In light of this problem, we proposed a "Panoramic Wireless Endoscope System design", hoping to provide physicians with a wide field of view of the endoscopic image. We combine images captured from two parallel-mounted endoscope lenses into a single, wide-angle image, giving physicians a wider field of view and easier access to the surgical area. In addition, we developed a wireless transmission system so the image can be transmitted to various display platforms, eliminating the needs for excessive cabling on surgical tools and enable physicians to better operate on the patient. Finally, our system allows surgical assistants a better view of the operation process, and enables other physicians and nurses to remotely observe the process. Our experiment results have shown that we can increase the image to 152% of its original size. We used the PandaBoard ES platform with an ARM9 processor and 1G of onboard RAM, and continuously implementing animal trials to verify the reliability of our system.

Advanced virtual endoscopy for endoscopic transsphenoidal pituitary surgery.

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Wolfsberger, Stefan; Neubauer, André; Bühler, Katja; Wegenkittl, Rainer; Czech, Thomas; Gentzsch, Stephan; Böcher-Schwarz, Hans-Gerd; Knosp, Engelbert

2006-11-01

Virtual endoscopy (vE) is the navigation of a camera through a virtual anatomical space that is computationally reconstructed from radiological image data. Inside this three-dimensional space, arbitrary movements and adaptations of viewing parameters are possible. Thereby, vE can be used for noninvasive diagnostic purposes and for simulation of surgical tasks. This article describes the development of an advanced system of vE for endoscopic transsphenoidal pituitary surgery and its application to teaching, training, and in the routine clinical setting. The vE system was applied to a series of 35 patients with pituitary pathology (32 adenomas, three Rathke's cleft cysts) operated endoscopically via the transsphenoidal route at the Department of Neurosurgery of the Medical University Vienna between 2004 and 2006. The virtual endoscopic images correlated well with the intraoperative view. For the transsphenoidal approach, vE improved intraoperative orientation by depicting anatomical landmarks and variations. For planning a safe and tailored opening of the sellar floor, transparent visualization of the pituitary adenoma and the normal gland in relation to the internal carotid arteries was useful. According to our experience, vE can be a valuable tool for endoscopic transsphenoidal pituitary surgery for training purposes and preoperative planning. For the novice, it can act as a simulator for endoscopic anatomy and for training surgical tasks. For the experienced pituitary surgeon, vE can depict the individual patient's anatomy, and may, therefore, improve intraoperative orientation. By prospectively visualizing unpredictable anatomical variations, vE may increase the safety of this surgical procedure.

Optical transfection using an endoscope-like system.

Science.gov (United States)

Ma, Nan; Gunn-Moore, Frank; Dholakia, Kishan

2011-02-01

Optical transfection is a powerful method for targeted delivery of therapeutic agents to biological cells. A tightly focused pulsed laser beam may transiently change the permeability of a cell membrane to facilitate the delivery of foreign genetic material into cells. We report the first realization of an endoscope-like integrated system for optical transfection. An imaging fiber (coherent optical fiber bundle) with ∼ 6000 cores (pixels) embedded in a fiber cladding of ∼ 300 μm in diameter, produces an image circle (area) of ∼ 270 μm diam. This imaging fiber, with an ordered axicon lens array chemically etched at its exit face, is used for the delivery of a femtosecond laser to the cell membrane for optical transfection along with subcellular resolution imaging. A microcapillary-based microfluidic system for localized drug delivery was also combined in this miniature, flexible system. Using this novel system, a plasmid transfection efficiency up to ∼ 72% was obtained for CHO-K1 cells. This endoscope-like system opens a range of exciting applications, in particular, in the targeted in vivo optical microsurgery area.

Endoscopic Endonasal Approach for a Suprasellar Craniopharyngioma.

Science.gov (United States)

Zenonos, Georgios A; Snyderman, Carl H; Gardner, Paul A

2018-04-01

Objectives  The current video presents the nuances of an endoscopic endonasal approach to a suprasellar craniopharyngioma. Design  The video analyzes the presentation, preoperative workup and imaging, surgical steps and technical nuances of the surgery, the clinical outcome, and follow-up imaging. Setting  The patient was treated by a skull base team consisting of a neurosurgeon and an ENT surgeon, at a teaching academic institution. Participants  The case refers to a 67-year-old man who presented with vision loss and headaches, and was found to have a suprasellar mass, with imaging characteristics consistent with a craniopharyngioma. Main Outcome Measures  The main outcome measures consistent of the reversal of the patient symptoms (vision loss and headaches), the recurrence-free survival based on imaging, as well as the absence of any complications. Results  The patient's vision improved after the surgery; at his last follow-up there was no evidence of recurrence on imaging. Conclusions  The endoscopic endonasal approach is safe and effective in treating suprasellar craniopharyngiomas. The link to the video can be found at: https://youtu.be/p1VXbwnAWCo .

Clinical endoscopic management and outcome of post-endoscopic sphincterotomy bleeding.

Directory of Open Access Journals (Sweden)

Wei-Chen Lin

Full Text Available Post-endoscopic sphincterotomy bleeding is a common complication of biliary sphincterotomy, and the incidence varies from 1% to 48%. It can be challenging to localize the bleeder or to administer various interventions through a side-viewing endoscope. This study aimed to evaluate the risk factors of post-endoscopic sphincterotomy bleeding and the outcome of endoscopic intervention therapies. We retrospectively reviewed the records of 513 patients who underwent biliary sphincterotomy in Mackay Memorial Hospital between 2011 and 2016. The blood biochemistry, comorbidities, indication for sphincterotomy, severity of bleeding, endoscopic features of bleeder, and type of endoscopic therapy were analyzed. Post-endoscopic sphincterotomy bleeding occurred in 65 (12.6% patients. Forty-five patients had immediate bleeding and 20 patients had delayed bleeding. The multivariate analysis of risk factors associated with post-endoscopic sphincterotomy bleeding were liver cirrhosis (P = 0.029, end-stage renal disease (P = 0.038, previous antiplatelet drug use (P<0.001, and duodenal ulcer (P = 0.023. The complications of pancreatitis and cholangitis were higher in the bleeding group, with statistical significance. Delayed bleeding occurred within 1 to 7 days (mean, 2.5 days, and 60% (12/20 of the patients received endoscopic evaluation. In the delayed bleeding group, the successful hemostasis rate was 71.4% (5/7, and 65% (13/20 of the patients had ceased bleeding without endoscopic hemostasis therapy. Comparison of different therapeutic modalities showed that cholangitis was higher in patients who received epinephrine spray (P = 0.042 and pancreatitis was higher in patients who received epinephrine injection and electrocoagulation (P = 0.041 and P = 0.039 respectively. Clinically, post-endoscopic sphincterotomy bleeding and further endoscopic hemostasis therapy increase the complication rate of pancreatitis and cholangitis. Realizing the effectiveness of each

Towards an ultra-thin medical endoscope: multimode fibre as a wide-field image transferring medium

Science.gov (United States)

Duriš, Miroslav; Bradu, Adrian; Podoleanu, Adrian; Hughes, Michael

2018-03-01

Multimode optical fibres are attractive for biomedical and industrial applications such as endoscopes because of the small cross section and imaging resolution they can provide in comparison to widely-used fibre bundles. However, the image is randomly scrambled by propagation through a multimode fibre. Even though the scrambling is unpredictable, it is deterministic, and therefore the scrambling can be reversed. To unscramble the image, we treat the multimode fibre as a linear, disordered scattering medium. To calibrate, we scan a focused beam of coherent light over thousands of different beam positions at the distal end and record complex fields at the proximal end of the fibre. This way, the inputoutput response of the system is determined, which then allows computational reconstruction of reflection-mode images. However, there remains the problem of illuminating the tissue via the fibre while avoiding back reflections from the proximal face. To avoid this drawback, we provide here the first preliminary confirmation that an image can be transferred through a 2x2 fibre coupler, with the sample at its distal port interrogated in reflection. Light is injected into one port for illumination and then collected from a second port for imaging.

Design and validation of a near-infrared fluorescence endoscope for detection of early esophageal malignancy using a targeted imaging probe

Science.gov (United States)

Waterhouse, Dale J.; Joseph, James; Neves, Andre A.; di Pietro, Massimiliano; Brindle, Kevin M.; Fitzgerald, Rebecca C.; Bohndiek, Sarah E.

2016-03-01

Barrett's esophagus is a condition that predisposes patients to esophageal cancer. Early detection of cancer in these patients can be curative, but is confounded by a lack of contrast in white light endoscopy (WLE). Application of fluorescently-labeled lectins to the esophagus during endoscopy can more accurately delineate dysplasia emerging within Barrett's than WLE1, but strong tissue autofluorescence has limited sensitivity and dynamic range of this approach. To overcome this challenge, we synthesized a near-infrared (NIR) fluorescent lectin and have constructed a clinically translatable endoscope for simultaneous WLE and NIR imaging. An imaging fiber bundle, shielded from patient contact using a disposable catheter, relays collected light into an optical path that splits the WL reflectance and NIR emission onto two cameras for simultaneous video-rate recording. The captured images are co-registered and the honeycomb artifact arising from the fiber bundle is removed using interpolation between image points derived from individual fibers. A minimum detectable concentration of 110 nM was determined using a dilution series of IRDye800CW-lectin in black well plates. We have demonstrated the ability to use our endoscope to distinguish between different tissue types in ex vivo mouse stomachs. Future work using human ex vivo tissue specimens will determine safe illumination limits and sensitivity for dysplasia and adenocarcinoma in Barrett's esophagus, prior to commencing clinical trials.

Fluorescence-Raman Dual Modal Endoscopic System for Multiplexed Molecular Diagnostics

Science.gov (United States)

Jeong, Sinyoung; Kim, Yong-Il; Kang, Homan; Kim, Gunsung; Cha, Myeong Geun; Chang, Hyejin; Jung, Kyung Oh; Kim, Young-Hwa; Jun, Bong-Hyun; Hwang, Do Won; Lee, Yun-Sang; Youn, Hyewon; Lee, Yoon-Sik; Kang, Keon Wook; Lee, Dong Soo; Jeong, Dae Hong

2015-03-01

Optical endoscopic imaging, which was recently equipped with bioluminescence, fluorescence, and Raman scattering, allows minimally invasive real-time detection of pathologies on the surface of hollow organs. To characterize pathologic lesions in a multiplexed way, we developed a dual modal fluorescence-Raman endomicroscopic system (FRES), which used fluorescence and surface-enhanced Raman scattering nanoprobes (F-SERS dots). Real-time, in vivo, and multiple target detection of a specific cancer was successful, based on the fast imaging capability of fluorescence signals and the multiplex capability of simultaneously detected SERS signals using an optical fiber bundle for intraoperative endoscopic system. Human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR) on the breast cancer xenografts in a mouse orthotopic model were successfully detected in a multiplexed way, illustrating the potential of FRES as a molecular diagnostic instrument that enables real-time tumor characterization of receptors during routine endoscopic procedures.

Spectrally enhanced imaging of occlusal surfaces and artificial shallow enamel erosions with a scanning fiber endoscope

Science.gov (United States)

Zhang, Liang; Nelson, Leonard Y.; Seibel, Eric J.

2012-07-01

An ultrathin scanning fiber endoscope, originally developed for cancer diagnosis, was used to image dental occlusal surfaces as well as shallow artificially induced enamel erosions from human extracted teeth (n=40). Enhanced image resolution of occlusal surfaces was obtained using a short-wavelength 405-nm illumination laser. In addition, artificial erosions of varying depths were also imaged with 405-, 404-, 532-, and 635-nm illumination lasers. Laser-induced autofluorescence images of the teeth using 405-nm illumination were also obtained. Contrast between sound and eroded enamel was quantitatively computed for each imaging modality. For shallow erosions, the image contrast with respect to sound enamel was greatest for the 405-nm reflected image. It was also determined that the increased contrast was in large part due to volume scattering with a smaller component from surface scattering. Furthermore, images obtained with a shallow penetration depth illumination laser (405 nm) provided the greatest detail of surface enamel topography since the reflected light does not contain contributions from light reflected from greater depths within the enamel tissue. Multilayered Monte Carlo simulations were also performed to confirm the experimental results.

Endoscopic Management of a Primary Duodenal Carcinoid Tumor

Directory of Open Access Journals (Sweden)

Albin Abraham

2012-03-01

Full Text Available Carcinoids are rare, slow-growing tumors originating from a variety of different neuroendocrine cell types. They are identified histologically by their affinity for silver salts and by positive reactions to neuroendocrine markers such as neuron-specific enolase, synaptophysin and chromogranin. They can present with various clinical symptoms and are difficult to diagnose. We present the case of a 43-year-old woman who was referred for evaluation of anemia. Upper endoscopy showed a duodenal bulb mass around 1 cm in size. Histopathological and immunohistochemistry staining were consistent with the diagnosis of a carcinoid tumor. Further imaging and endoscopic studies showed no other synchronous carcinoid lesions. Endoscopic ultrasound (EUS revealed a 1 cm lesion confined to the mucosa and no local lymphadenopathy. Successful endoscopic mucosal resection of the mass was performed. Follow-up surveillance 6 months later with EUS and Octreoscan revealed no new lesions suggestive of recurrence. No consensus guidelines exist for the endoscopic management of duodenal carcinoid tumors. However, endoscopic resection is safe and preferred for tumors measuring 1 cm or less with no evidence of invasion of the muscularis layer.

Virtualized endoscope system. An application of virtual reality technology to diagnostic aid

International Nuclear Information System (INIS)

Mori, Kensaku; Urano, Akihiro; Toriwaki, Jun-ichiro; Hasegawa, Jun-ichi; Anno, Hirofumi; Katada, Kazuhiro.

1996-01-01

In this paper we propose a new medical image processing system called 'Virtualized Endoscope System (VES)', which can examine the inside of a virtualized human body. The virtualized human body is a 3-D digital image which is taken by such as X-ray CT scanner or MRI scanner. VES consists of three modules; (1) imaging, (2) segmentation and reconstruction and (3) interactive operation. The interactive operation module has following three major functions; (a) display of, (b) measurement from, and (c) manipulation to the virtualized human body. The user of the system can observe freely both the inside and the outside of a target organ from any point and any direction freely, and can perform necessary measurement interactively concerning angle and length at any time during observation. VES enables to observe repeatedly an area where the real endoscope can not enter without pain from any direction which the real endoscope can not. We applied this system to real 3-D X-ray CT images and obtained good result. (author)

The role of contrast-enhanced endoscopic ultrasound in pancreatic adenocarcinoma

DEFF Research Database (Denmark)

Saftoiu, Adrian; Vilmann, Peter; Bhutani, Manoop S

2016-01-01

contrast agents for early detection, tridimensional and fusion techniques for enhanced staging and resectability assessment but also novel applications of perfusion imaging for monitoring ablative therapy, improved local detection through EUS-guided sampling of portal vein flow or enhanced drug delivery......Contrast-enhanced endoscopic ultrasound (CE-EUS) allows characterization, differentiation, and staging of focal pancreatic masses. The method has a high sensitivity and specificity for the diagnosis of pancreatic adenocarcinoma which is visualized as hypo-enhanced as compared to the rest...... of the parenchyma while chronic pancreatitis and neuroendocrine tumors are generally either iso-enhanced or hyper-enhanced. The development of contrast-enhanced low mechanical index harmonic imaging techniques used in real time during endoscopic ultrasound (EUS) allowed perfusion imaging and the quantification...

Image-based overlay and alignment metrology through optically opaque media with sub-surface probe microscopy

Science.gov (United States)

van Es, Maarten H.; Mohtashami, Abbas; Piras, Daniele; Sadeghian, Hamed

2018-03-01

Nondestructive subsurface nanoimaging through optically opaque media is considered to be extremely challenging and is essential for several semiconductor metrology applications including overlay and alignment and buried void and defect characterization. The current key challenge in overlay and alignment is the measurement of targets that are covered by optically opaque layers. Moreover, with the device dimensions moving to the smaller nodes and the issue of the so-called loading effect causing offsets between between targets and product features, it is increasingly desirable to perform alignment and overlay on product features or so-called on-cell overlay, which requires higher lateral resolution than optical methods can provide. Our recently developed technique known as SubSurface Ultrasonic Resonance Force Microscopy (SSURFM) has shown the capability for high-resolution imaging of structures below a surface based on (visco-)elasticity of the constituent materials and as such is a promising technique to perform overlay and alignment with high resolution in upcoming production nodes. In this paper, we describe the developed SSURFM technique and the experimental results on imaging buried features through various layers and the ability to detect objects with resolution below 10 nm. In summary, the experimental results show that the SSURFM is a potential solution for on-cell overlay and alignment as well as detecting buried defects or voids and generally metrology through optically opaque layers.

[Inspecting the cochlear scala tympanic with flexible and semi-flexible micro-endoscope].

Science.gov (United States)

Zhang, Daoxcing; Zhang, Yankun

2006-02-01

Flexible and semi-flexible micro-endoscopes were used in cochlear scala tympani inspection , to explore their application in inner ear examination. Fifteen profound hearing loss patients preparing for cochlear implant were included in this study. During the operation, micro-endoscopy was performed after opening the cochlear scala tympani. And 1 mm diameter semi-flexible micro-endoscope could go as deep as 9 mm into the cochlear scala tympani, while 0. 5 mm diameter flexible micro-endoscope could go as deep as 25 mm. The inspecting results were compared with video recording. Using 0.5 mm flexible micro-endoscope, we canould check cochlear scala tympani with depth range of 15-25 mm, but the video imaging was not clear enough to examine the microstructure in the cochlear. With 1 mm diameter semi-flexible micro-endoscope, we could reach 9 mm deep into the cochlear. During the examination, we found 3 cases with calcification deposit in osseous spiral lamina, l case with granulation tissue in the lateral wall of scala tympani, no abnormal findings in the other 11 cases. Inspecting the cochlear scala tympani with 0.5 mm flexible micro-endoscope, even though we can reach the second circuit of the cochlear, it is difficult to find the pathology in the cochlear because of the poor video imaging. With 1 mm semi-flexible micro-endoscope, we can identify the microstructure of the cochlear clearly and find the pathologic changes, but the inserting depth was limited to 9 mm with limitation to examine the whole cochlear.

Endoscopic anatomy of the orbital floor and maxillary sinus.

Science.gov (United States)

Moore, Corey C; Bromwich, Matthew; Roth, Kathy; Matic, Damir B

2008-01-01

Endoscopic repair of orbital blow-out fractures could become a predictable and efficient treatment alternative to traditional methods. However, maxillary sinus endoscopy provides a complex and disorienting view of the orbital floor. To be a useful and consistent technique for providing access to the orbital floor, specific knowledge of maxillary endoscopic anatomy is required. The purpose of the study was to provide an anatomic description of the orbital floor via the endoscopic approach. Objectives include defining consistent landmarks for use in endoscopic repair of orbital floor fractures. Using 0- and 30-degree rigid endoscopes, 6 fresh cadavers (12 maxillary sinuses) were examined via a standard Caldwell-Luc approach. Computed tomographic scans, plastic molds, and digital images were used to compare observable averages within bony anatomy. Potential bony landmarks were correlated with soft-tissue anatomy in fresh specimens. The maxillary ostium, orbital floor, and lateral ethmoid air cells were visualized, and their structures were described. Observations were made in relation to the anatomy of the orbital floor and maxillary sinus, including fracture pattern and force transmission pathways. An "orbitomaxillary" sinus bony thickening was identified and described for the first time. This study provides the basis for further refinement of surgical technique and opens the door for future clinical trials using endoscopic repair.

Endoscopic Therapeutic Approach for Dysplasia in Inflammatory Bowel Disease

Directory of Open Access Journals (Sweden)

Sung Noh Hong

2017-09-01

Full Text Available Long-standing intestinal inflammation in patients with inflammatory bowel disease (IBD induces dysplastic change in the intestinal mucosa and increases the risk of subsequent colorectal cancer. The evolving endoscopic techniques and technologies, including dye spraying methods and high-definition images, have been replacing random biopsies and have been revealed as more practical and efficient for detection of dysplasia in IBD patients. In addition, they have potential usefulness in detailed characterization of lesions and in the assessment of endoscopic resectability. Most dysplastic lesions without an unclear margin, definite ulceration, non-lifting sign, and high index of malignant change with suspicion for lymph node or distant metastases can be removed endoscopically. However, endoscopic resection of dysplasia in chronic IBD patients is usually difficult because it is often complicated by submucosal fibrosis. In patients with dysplasias that demonstrate submucosa fibrosis or a large size (≥20 mm, endoscopic submucosal dissection (ESD or ESD with snaring (simplified or hybrid ESD is an alternative option and may avoid a colectomy. However, a standardized endoscopic therapeutic approach for dysplasia in IBD has not been established yet, and dedicated specialized endoscopists with interest in IBD are needed to fully investigate recent emerging techniques and technologies.

Endoscopic Ultrasound Elastography: Current Clinical Use in Pancreas.

Science.gov (United States)

Mondal, Utpal; Henkes, Nichole; Patel, Sandeep; Rosenkranz, Laura

2016-08-01

Elastography is a newer technique for the assessment of tissue elasticity using ultrasound. Cancerous tissue is known to be stiffer (hence, less elastic) than corresponding healthy tissue, and as a result, could be identified in an elasticity-based imaging. Ultrasound elastography has been used in the breast, thyroid, and cervix to differentiate malignant from benign neoplasms and to guide or avoid unnecessary biopsies. In the liver, elastography has enabled a noninvasive and reliable estimate of fibrosis. Endoscopic ultrasound has become a robust diagnostic and therapeutic tool for the management of pancreatic diseases. The addition of elastography to endoscopic ultrasound enabled further characterization of pancreas lesions, and several European and Asian studies have reported encouraging results. The current clinical role of endoscopic ultrasound elastography in the management of pancreas disorders and related literature are reviewed.

Intravascular ultrasonic-photoacoustic (IVUP) endoscope with 2.2-mm diameter catheter for medical imaging.

Science.gov (United States)

Bui, Nhat Quang; Hlaing, Kyu Kyu; Nguyen, Van Phuc; Nguyen, Trung Hau; Oh, Yun-Ok; Fan, Xiao Feng; Lee, Yong Wook; Nam, Seung Yun; Kang, Hyun Wook; Oh, Junghwan

2015-10-01

Intravascular ultrasound (IVUS) imaging is extremely important for detection and characterization of high-risk atherosclerotic plaques as well as gastrointestinal diseases. Recently, intravascular photoacoustic (IVPA) imaging has been used to differentiate the composition of biological tissues with high optical contrast and ultrasonic resolution. The combination of these imaging techniques could provide morphological information and molecular screening to characterize abnormal tissues, which would help physicians to ensure vital therapeutic value and prognostic significance for patients before commencing therapy. In this study, integration of a high-frequency IVUS imaging catheter (45MHz, single-element, unfocused, 0.7mm in diameter) with a multi-mode optical fiber (0.6mm in core diameter, 0.22 NA), an integrated intravascular ultrasonic-photoacoustic (IVUP) imaging catheter, was developed to provide spatial and functional information on light distribution in a turbid sample. Simultaneously, IVUS imaging was co-registered to IVPA imaging to construct 3D volumetric sample images. In a phantom study, a polyvinyl alcohol (PVA) tissue-mimicking arterial vessel phantom with indocyanine green (ICG) and methylene blue (MB) inclusion was used to demonstrate the feasibility of mapping the biological dyes, which are used in cardiovascular and cancer diagnostics. For the ex vivo study, an excised sample of pig intestine with ICG was utilized to target the biomarkers present in the gastrointestinal tumors or the atherosclerotic plaques with the proposed hybrid technique. The results indicated that IVUP endoscope with the 2.2-mm diameter catheter could be a useful tool for medical imaging. Copyright © 2015 Elsevier Ltd. All rights reserved.

CMP reflection imaging via interferometry of distributed subsurface sources

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Kim, D.; Brown, L. D.; Quiros, D. A.

2015-12-01

The theoretical foundations of recovering body wave energy via seismic interferometry are well established. However in practice, such recovery remains problematic. Here, synthetic seismograms computed for subsurface sources are used to evaluate the geometrical combinations of realistic ambient source and receiver distributions that result in useful recovery of virtual body waves. This study illustrates how surface receiver arrays that span a limited distribution suite of sources, can be processed to reproduce virtual shot gathers that result in CMP gathers which can be effectively stacked with traditional normal moveout corrections. To verify the feasibility of the approach in practice, seismic recordings of 50 aftershocks following the magnitude of 5.8 Virginia earthquake occurred in August, 2011 have been processed using seismic interferometry to produce seismic reflection images of the crustal structure above and beneath the aftershock cluster. Although monotonic noise proved to be problematic by significantly reducing the number of usable recordings, the edited dataset resulted in stacked seismic sections characterized by coherent reflections that resemble those seen on a nearby conventional reflection survey. In particular, "virtual" reflections at travel times of 3 to 4 seconds suggest reflector sat approximately 7 to 12 km depth that would seem to correspond to imbricate thrust structures formed during the Appalachian orogeny. The approach described here represents a promising new means of body wave imaging of 3D structure that can be applied to a wide array of geologic and energy problems. Unlike other imaging techniques using natural sources, this technique does not require precise source locations or times. It can thus exploit aftershocks too small for conventional analyses. This method can be applied to any type of microseismic cloud, whether tectonic, volcanic or man-made.

Coherent anti-Stokes Raman scattering rigid endoscope toward robot-assisted surgery.

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Hirose, K; Aoki, T; Furukawa, T; Fukushima, S; Niioka, H; Deguchi, S; Hashimoto, M

2018-02-01

Label-free visualization of nerves and nervous plexuses will improve the preservation of neurological functions in nerve-sparing robot-assisted surgery. We have developed a coherent anti-Stokes Raman scattering (CARS) rigid endoscope to distinguish nerves from other tissues during surgery. The developed endoscope, which has a tube with a diameter of 12 mm and a length of 270 mm, achieved 0.91% image distortion and 8.6% non-uniformity of CARS intensity in the whole field of view (650 μm diameter). We demonstrated CARS imaging of a rat sciatic nerve and visualization of the fine structure of nerve fibers.

A discriminative structural similarity measure and its application to video-volume registration for endoscope three-dimensional motion tracking.

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Luo, Xiongbiao; Mori, Kensaku

2014-06-01

Endoscope 3-D motion tracking, which seeks to synchronize pre- and intra-operative images in endoscopic interventions, is usually performed as video-volume registration that optimizes the similarity between endoscopic video and pre-operative images. The tracking performance, in turn, depends significantly on whether a similarity measure can successfully characterize the difference between video sequences and volume rendering images driven by pre-operative images. The paper proposes a discriminative structural similarity measure, which uses the degradation of structural information and takes image correlation or structure, luminance, and contrast into consideration, to boost video-volume registration. By applying the proposed similarity measure to endoscope tracking, it was demonstrated to be more accurate and robust than several available similarity measures, e.g., local normalized cross correlation, normalized mutual information, modified mean square error, or normalized sum squared difference. Based on clinical data evaluation, the tracking error was reduced significantly from at least 14.6 mm to 4.5 mm. The processing time was accelerated more than 30 frames per second using graphics processing unit.

Geophysical characterization of subsurface barriers

International Nuclear Information System (INIS)

Borns, D.J.

1995-08-01

An option for controlling contaminant migration from plumes and buried waste sites is to construct a subsurface barrier of a low-permeability material. The successful application of subsurface barriers requires processes to verify the emplacement and effectiveness of barrier and to monitor the performance of a barrier after emplacement. Non destructive and remote sensing techniques, such as geophysical methods, are possible technologies to address these needs. The changes in mechanical, hydrologic and chemical properties associated with the emplacement of an engineered barrier will affect geophysical properties such a seismic velocity, electrical conductivity, and dielectric constant. Also, the barrier, once emplaced and interacting with the in situ geologic system, may affect the paths along which electrical current flows in the subsurface. These changes in properties and processes facilitate the detection and monitoring of the barrier. The approaches to characterizing and monitoring engineered barriers can be divided between (1) methods that directly image the barrier using the contrasts in physical properties between the barrier and the host soil or rock and (2) methods that reflect flow processes around or through the barrier. For example, seismic methods that delineate the changes in density and stiffness associated with the barrier represents a direct imaging method. Electrical self potential methods and flow probes based on heat flow methods represent techniques that can delineate the flow path or flow processes around and through a barrier

Ultrahigh speed endoscopic optical coherence tomography using micromotor imaging catheter and VCSEL technology.

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Tsai, Tsung-Han; Potsaid, Benjamin; Tao, Yuankai K; Jayaraman, Vijaysekhar; Jiang, James; Heim, Peter J S; Kraus, Martin F; Zhou, Chao; Hornegger, Joachim; Mashimo, Hiroshi; Cable, Alex E; Fujimoto, James G

2013-07-01

We developed a micromotor based miniature catheter with an outer diameter of 3.2 mm for ultrahigh speed endoscopic swept source optical coherence tomography (OCT) using a vertical cavity surface-emitting laser (VCSEL) at a 1 MHz axial scan rate. The micromotor can rotate a micro-prism at several hundred frames per second with less than 5 V drive voltage to provide fast and stable scanning, which is not sensitive to the bending of the catheter. The side-viewing probe can be pulled back to acquire a three-dimensional (3D) data set covering a large area on the specimen. The VCSEL provides a high axial scan rate to support dense sampling under high frame rate operation. Using a high speed data acquisition system, in vivo 3D-OCT imaging in the rabbit GI tract and ex vivo imaging of a human colon specimen with 8 μm axial resolution, 8 μm lateral resolution and 1.2 mm depth range in tissue at a frame rate of 400 fps was demonstrated.

Endoscopic root canal treatment.

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Moshonov, Joshua; Michaeli, Eli; Nahlieli, Oded

2009-10-01

To describe an innovative endoscopic technique for root canal treatment. Root canal treatment was performed on 12 patients (15 teeth), using a newly developed endoscope (Sialotechnology), which combines an endoscope, irrigation, and a surgical microinstrument channel. Endoscopic root canal treatment of all 15 teeth was successful with complete resolution of all symptoms (6-month follow-up). The novel endoscope used in this study accurately identified all microstructures and simplified root canal treatment. The endoscope may be considered for use not only for preoperative observation and diagnosis but also for active endodontic treatment.

Visual servoing in medical robotics: a survey. Part I: endoscopic and direct vision imaging - techniques and applications.

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Azizian, Mahdi; Khoshnam, Mahta; Najmaei, Nima; Patel, Rajni V

2014-09-01

Intra-operative imaging is widely used to provide visual feedback to a clinician when he/she performs a procedure. In visual servoing, surgical instruments and parts of tissue/body are tracked by processing the acquired images. This information is then used within a control loop to manoeuvre a robotic manipulator during a procedure. A comprehensive search of electronic databases was completed for the period 2000-2013 to provide a survey of the visual servoing applications in medical robotics. The focus is on medical applications where image-based tracking is used for closed-loop control of a robotic system. Detailed classification and comparative study of various contributions in visual servoing using endoscopic or direct visual images are presented and summarized in tables and diagrams. The main challenges in using visual servoing for medical robotic applications are identified and potential future directions are suggested. 'Supervised automation of medical robotics' is found to be a major trend in this field. Copyright © 2013 John Wiley & Sons, Ltd.

Pneumoretroperitoneum and Sepsis After Transanal Endoscopic Resection of a Rectal Lateral Spreading Tumor

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Coura, Marcelo de Melo Andrade; de Almeida, Romulo Medeiros; Moreira, Natascha Mourão; de Sousa, João Batista; de Oliveira, Paulo Gonçalves

2017-01-01

Transanal endoscopic microsurgery is considered a safe, appropriate, and minimally invasive approach, and complications after endoscopic microsurgery are rare. We report a case of sepsis and pneumoretroperitoneum after resection of a rectal lateral spreading tumor. The patient presented with rectal mucous discharge. Colonoscopy revealed a rectal lateral spreading tumor. The patient underwent an endoscopic transanal resection of the lesion. He presented with sepsis of the abdominal focus, and imaging tests revealed pneumoretroperitoneum. A new surgical intervention was performed with a loop colostomy. Despite the existence of other reports on pneumoretroperitoneum after transanal endoscopic microsurgery, what draws attention to this case is the association with sepsis. PMID:28761873

[Transsphenoidal endoscopic endonasal approach for the surgery of pituitary abscess].

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Yu, Huanxin; Liu, Gang

2014-01-01

To evaluate the effectiveness of transsphenoidal endoscopic endonasal approach for the surgery of pituitary abscess. Eighteen pathologically diagnosed pituitary abscess were resected through transsphenoidal endoscopic endonasal approach at Tianjing Huanhu hospital between January 2000 and December 2011.Retrospective analysis was done upon clinical presentations and imaging features. There were 6 males and 12 females. The average age was 48.5 years old and the average disease course was 5.8 years. The typical clinical manifestations included headache (13 cases), pituitary dysfunction (10 cases), Diabetes Insipidus (4 cases) visual interference (8 cases) and fever (4 cases). All cases were resected by transsphenoidal endoscopic endonasal approach with general anesthesia. The postoperative symptoms and follow-up results were recorded. All patients were followed up from 6 months to 6 years. Postoperatively, headache was recovered in 13 cases, visual was improved in 6 cases, hypopituitarism was relieved in 8 cases and polyuria was disappeared in 3 cases. One case was recurrent and cured by transsphenoidal endoscopic endonasal approach. Transsphenoidal endoscopic endonasal approach for the surgery of pituitary abscess is effective.

Imaging in the Evaluation of Endoscopic or Surgical Treatment for Achalasia

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Diego Palladino

2016-01-01

Full Text Available Purpose. Aim of the study is to evaluate the efficacy of the endoscopic (pneumatic dilation versus surgical (Heller myotomy treatment in patients affected by esophageal achalasia using barium X-ray examination of the digestive tract performed before and after the treatment. Materials and Methods. 19 patients (10 males and 9 females were enrolled in this study; each patient underwent a barium X-ray examination to evaluate the esophageal diameter and the height of the barium column before and after endoscopic or surgical treatment. Results. The mean variation of oesophageal diameter before and after treatment is −2.1 mm for surgery and 1.74 mm for pneumatic dilation (OR 0.167, CI 95% 0.02–1.419, and P: 0.10. The variations of all variables, with the exception of the oesophageal diameter variation, are strongly related to the treatment performed. Conclusions. The barium X-ray study of the digestive tract, performed before and after different treatment approaches, demonstrates that the surgical treatment has to be considered as the treatment of choice of achalasia, reserving endoscopic treatment to patients with high operative risk and refusing surgery.

Optical fiber-based full Mueller polarimeter for endoscopic imaging using a two-wavelength simultaneous measurement method.

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Vizet, Jérémy; Manhas, Sandeep; Tran, Jacqueline; Validire, Pierre; Benali, Abdelali; Garcia-Caurel, Enric; Pierangelo, Angelo; De Martino, Antonello; Pagnoux, Dominique

2016-07-01

This paper reports a technique based on spectrally differential measurement for determining the full Mueller matrix of a biological sample through an optical fiber. In this technique, two close wavelengths were used simultaneously, one for characterizing the fiber and the other for characterizing the assembly of fiber and sample. The characteristics of the fiber measured at one wavelength were used to decouple its contribution from the measurement on the assembly of fiber and sample and then to extract sample Mueller matrix at the second wavelength. The proof of concept was experimentally validated by measuring polarimetric parameters of various calibrated optical components through the optical fiber. Then, polarimetric images of histological cuts of human colon tissues were measured, and retardance, diattenuation, and orientation of the main axes of fibrillar regions were displayed. Finally, these images were successfully compared with images obtained by a free space Mueller microscope. As the reported method does not use any moving component, it offers attractive integration possibilities with an endoscopic probe.

Automatic real-time detection of endoscopic procedures using temporal features.

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Stanek, Sean R; Tavanapong, Wallapak; Wong, Johnny; Oh, Jung Hwan; de Groen, Piet C

2012-11-01

Endoscopy is used for inspection of the inner surface of organs such as the colon. During endoscopic inspection of the colon or colonoscopy, a tiny video camera generates a video signal, which is displayed on a monitor for interpretation in real-time by physicians. In practice, these images are not typically captured, which may be attributed by lack of fully automated tools for capturing, analysis of important contents, and quick and easy retrieval of these contents. This paper presents the description and evaluation results of our novel software that uses new metrics based on image color and motion over time to automatically record all images of an individual endoscopic procedure into a single digitized video file. The software automatically discards out-patient video frames between different endoscopic procedures. We validated our software system on 2464 h of live video (over 265 million frames) from endoscopy units where colonoscopy and upper endoscopy were performed. Our previous classification method achieved a frame-based sensitivity of 100.00%, but only a specificity of 89.22%. Our new method achieved a frame-based sensitivity and specificity of 99.90% and 99.97%, a significant improvement. Our system is robust for day-to-day use in medical practice. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Endoscopic retrograde cholanglopancreatography

International Nuclear Information System (INIS)

Horii, S.C.; Garra, B.S.; Zeman, R.K.; Krasner, B.H.; Lo, S.C.B.; Davros, W.J.; Silverman, P.M.; Cattau, E.L.; Fleischer, D.E.; Benjamin, S.B.S.B.

1989-01-01

As part of the clinical evaluation of image management and communications system (IMACS), the authors undertook a prospective study to compare conventional film versus digitized film viewed on a workstation. Twenty-five each of normal and abnormal endoscopic retrograde cholangiopancreatographic (ERCP) studies were digitized with a 1,684 x 2,048-pixel matrix and evaluated in a single-blind fashion on the workstation. The resulting interpretations were then compared with those resulting from interpretation of film (spot film and 100-mm photospot) images. They report that no significant differences were found in ability to see anatomic detail or pathology. A second study involved performing 10 ERCP studies in a lithotripsy suite equipped with biplane digital fluoroscopy. The digital video displays were comparable in quality to that of film. Progress is being made in using the IMACS for archiving and retrieval of all current ERCP images

Interactive navigation-guided ophthalmic plastic surgery: navigation enabling of telescopes and their use in endoscopic lacrimal surgeries

Directory of Open Access Journals (Sweden)

Ali MJ

2016-11-01

Full Text Available Mohammad Javed Ali,1 Swati Singh,1 Milind N Naik,1 Swathi Kaliki,2 Tarjani Vivek Dave1 1The Institute of Dacryology, 2The Operation Eyesight Universal Institute for Eye Cancer, L.V. Prasad Eye Institute, Hyderabad, India Purpose: The aims of this study were to report the preliminary experience of using telescopes, which were enabled for navigation guidance, and their utility in complex endoscopic lacrimal surgeries. Methods: Navigation enabling of the telescope was achieved by using the AxiEM™ malleable neuronavigation shunt stylet. Image-guided dacryolocalization was performed in five patients using the intraoperative image-guided StealthStation™ system in the electromagnetic mode. The “look ahead” protocol software was used to assist the surgeon in assessing the intraoperative geometric location of the endoscope and what lies ahead in real time. All patients underwent navigation-guided powered endoscopic dacryocystorhinostomy. The utility of uninterrupted navigation guidance throughout the surgery with the endoscope as the navigating tool was noted. Results: Intraoperative geometric localization of the lacrimal sac and the nasolacrimal duct could be easily deciphered. Constant orientation of the lacrimal drainage system and the peri-lacrimal anatomy was possible without the need for repeated point localizations throughout the surgery. The “look ahead” features could accurately alert the surgeon of anatomical structures that exists at 5, 10 and 15 mm in front of the endoscope. Good securing of the shunt stylet with the telescope was found to be essential for constant and accurate navigation. Conclusion: Navigation-enabled endoscopes provide the surgeon with the advantage of sustained stereotactic anatomical awareness at all times during the surgery. Keywords: telescope, endoscope, image guidance, navigation, lacrimal surgery, powered endoscopic DCR

Multimodal Navigation in Endoscopic Transsphenoidal Resection of Pituitary Tumors Using Image-Based Vascular and Cranial Nerve Segmentation: A Prospective Validation Study.

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Dolati, Parviz; Eichberg, Daniel; Golby, Alexandra; Zamani, Amir; Laws, Edward

2016-11-01

Transsphenoidal surgery (TSS) is the most common approach for the treatment of pituitary tumors. However, misdirection, vascular damage, intraoperative cerebrospinal fluid leakage, and optic nerve injuries are all well-known complications, and the risk of adverse events is more likely in less-experienced hands. This prospective study was conducted to validate the accuracy of image-based segmentation coupled with neuronavigation in localizing neurovascular structures during TSS. Twenty-five patients with a pituitary tumor underwent preoperative 3-T magnetic resonance imaging (MRI), and MRI images loaded into the navigation platform were used for segmentation and preoperative planning. After patient registration and subsequent surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe or Doppler probe on or as close as possible to the target. Preoperative segmentation of the internal carotid artery and cavernous sinus matched with the intraoperative endoscopic and micro-Doppler findings in all cases. Excellent correspondence between image-based segmentation and the endoscopic view was also evident at the surface of the tumor and at the tumor-normal gland interfaces. Image guidance assisted the surgeons in localizing the optic nerve and chiasm in 64% of cases. The mean accuracy of the measurements was 1.20 ± 0.21 mm. Image-based preoperative vascular and neural element segmentation, especially with 3-dimensional reconstruction, is highly informative preoperatively and potentially could assist less-experienced neurosurgeons in preventing vascular and neural injury during TSS. In addition, the accuracy found in this study is comparable to previously reported neuronavigation measurements. This preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Sphincter of Oddi stenosis: diagnosis using hepatobiliary scintigraphy and endoscopic manometry

International Nuclear Information System (INIS)

Lee, R.G.L.; Gregg, J.A.; Koroshetz, A.M.; Hill, T.C.; Clouse, M.E.

1985-01-01

To determine the role of radionuclide imaging in diagnosing sphincter of Oddi stenosis, 21 patients with symptoms suggesting this disorder underwent endoscopic retrograde cholangiopancreatography, cholescintigraphy, and, when possible, endoscopic manometry. Those patients with abnormal hepatobiliary scintigraphy results had a mean basal sphincter pressure of 38.5 mm Hg. Sphincter pressures could not be measured in six patients with sphincters too tight to cannulate. Ten patients who underwent hepatobiliary scanning both before and after sphincter surgery had normal scan results of the repeat study. Hepatobiliary imaging appears useful for diagnosis of sphincter of Oddi stenosis in selected patients in whom manometry cannot be performed and for objective assessment of response to therapy

An Automatic Framework Using Space-Time Processing and TR-MUSIC for Subsurface and Through-Wall Multitarget Imaging

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Si-hao Tan

2012-01-01

Full Text Available We present an automatic framework combined space-time signal processing with Time Reversal electromagnetic (EM inversion for subsurface and through-wall multitarget imaging using electromagnetic waves. This framework is composed of a frequency-wavenumber (FK filter to suppress direct wave and medium bounce, a FK migration algorithm to automatically estimate the number of targets and identify target regions, which can be used to reduce the computational complexity of the following imaging algorithm, and a EM inversion algorithm using Time Reversal Multiple Signal Classification (TR-MUSIC to reconstruct hidden objects. The feasibility of the framework is demonstrated with simulated data generated by GPRMAX.

Update on endoscopic pancreatic function testing

Institute of Scientific and Technical Information of China (English)

Tyler Stevens; Mansour A Parsi

2011-01-01

Hormone-stimulated pancreatic function tests (PFTs) are considered the gold standard for measuring pancreatic exocrine function. PFTs involve the administration of intravenous secretin or cholecystokinin, followed by collection and analysis of pancreatic secretions. Because exocrine function may decline in the earliest phase of pancreatic fibrosis, PFTs are considered accurate for diagnosing chronic pancreatitis. Unfortunately, these potentially valuable tests are infrequently performed except at specialized centers, because they are time consuming and complicated. To overcome these limitations, endoscopic PFT methods have been developed which include aspiration of pancreatic secretions through the suction channel of the endoscope. The secretin endoscopic pancreatic function test (ePFT) involves collection of duodenal aspirates at 15, 30, 45 and 60 min after secretin stimulation. A bicarbonate concentration greater than 80 mmol/L in any of the samples is considered a normal result. The secretin ePFT has demonstrated good sensitivity and specificity compared with various reference standards, including the "Dreiling tube" secretin PFT, endoscopic ultrasound, and surgical histology. Furthermore, a standard autoanalyzer can be used for bicarbonate analysis, which allows the secretin ePFT to be performed at any hospital. The secretin ePFT may complement imaging tests like endoscopic ultrasound (EUS) in the diagnosis of early chronic pancreatitis.This paper will review the literature validating the use of ePFT in the diagnosis of exocrine insufficiency and chronic pancreatitis. Newer developments will also be discussed, including the feasibility of combined EUS/ePFT, the use of cholecystokinin alone or in combination with secretin, and the discovery of new protein and lipid pancreatic juice biomarkers which may complement traditionalfluid analysis.

Tuberculosis and the pancreas: a diagnostic challenge solved by endoscopic ultrasound. A case series.

Science.gov (United States)

Chatterjee, Suvadip; Schmid, Matthias L; Anderson, Kirsty; Oppong, Kofi W

2012-03-01

Pancreatic tuberculosis is a rare disease. It can be easily confused with malignancy or pancreatitis on imaging. This could result in unnecessary surgery. As this is a treatable disease it is imperative to diagnose this condition pre-operatively. We report three cases of pancreatic tuberculosis that were diagnosed by endoscopic ultrasound. In conclusion, endoscopic ultrasound is the diagnostic modality of choice for pancreatic tuberculosis facilitating high resolution imaging, as well as sampling of tissue for staining, cytology, culture and polymerase chain reaction assay.

Progress in Molecular Imaging in Endoscopy and Endomicroscopy for Cancer Imaging

Directory of Open Access Journals (Sweden)

Supang Khondee

2013-01-01

Full Text Available Imaging is an essential tool for effective cancer management. Endoscopes are important medical instruments for performing in vivo imaging in hollow organs. Early detection of cancer can be achieved with surveillance using endoscopy, and has been shown to reduce mortality and to improve outcomes. Recently, great advancements have been made in endoscopic instruments, including new developments in optical designs, light sources, optical fibers, miniature scanners, and multimodal systems, allowing for improved resolution, greater tissue penetration, and multispectral imaging. In addition, progress has been made in the development of highly-specific optical probes, allowing for improved specificity for molecular targets. Integration of these new endoscopic instruments with molecular probes provides a unique opportunity for significantly improving patient outcomes and has potential to further improve early detection, image guided therapy, targeted therapy, and personalized medicine. This work summarizes current and evolving endoscopic technologies, and provides an overview of various promising optical molecular probes.

Modelling of a laser-pumped light source for endoscopic surgery

Science.gov (United States)

Nadeau, Valerie J.; Elson, Daniel S.; Hanna, George B.; Neil, Mark A. A.

2008-09-01

A white light source, based on illumination of a yellow phosphor with a fibre-coupled blue-violet diode laser, has been designed and built for use in endoscopic surgery. This narrow light probe can be integrated into a standard laparoscope or inserted into the patient separately via a needle. We present a Monte Carlo model of light scattering and phosphorescence within the phosphor/silicone matrix at the probe tip, and measurements of the colour, intensity, and uniformity of the illumination. Images obtained under illumination with this light source are also presented, demonstrating the improvement in illumination quality over existing endoscopic light sources. This new approach to endoscopic lighting has the advantages of compact design, improved ergonomics, and more uniform illumination in comparison with current technologies.

Liver parenchumography following endoscopic retrograde cholangiopancreatography (ERCP)

International Nuclear Information System (INIS)

Revert, A.; Arana, E.; Pertejo, V.; Berenguer, M.; Masip, M.J.

1998-01-01

Focal liver opacification during endoscopic retrograde cholangiography (ERCP) is an uncommon complication caused by excessive pressure during contrast injection. In this situation, ERCP must be interrupted and the position of the cannula checked. We recommend that these images be excluded from the diagnosis of tumor or cystic cavities. 4 refs

Ultrathin endoscopes based on multicore fibers and adaptive optics: a status review and perspectives.

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Andresen, Esben Ravn; Sivankutty, Siddharth; Tsvirkun, Viktor; Bouwmans, Géraud; Rigneault, Hervé

2016-12-01

We take stock of the progress that has been made into developing ultrathin endoscopes assisted by wave front shaping. We focus our review on multicore fiber-based lensless endoscopes intended for multiphoton imaging applications. We put the work into perspective by comparing with alternative approaches and by outlining the challenges that lie ahead.

In vivo subsurface morphological and functional cellular and subcellular imaging of the gastrointestinal tract with confocal mini-microscopy

Institute of Scientific and Technical Information of China (English)

Martin Goetz; Beena Memadathil; Stefan Biesterfeld; Constantin Schneider; Sebastian Gregor; Peter R Galle; Markus F Neurath; Ralf Kiesslich

2007-01-01

AIM: To evaluate a newly developed hand-held confocal probe for in vivo microscopic imaging of the complete gastrointestinal tract in rodents.METHODS: A novel rigid confocal probe (diameter 7 mm) was designed with optical features similar to the flexible endomicroscopy system for use in humans using a 488 nm single line laser for fluorophore excitation.Light emission was detected at 505 to 750 nm. The field of view was 475 μm × 475 μm. Optical slice thickness was 7 μm with a lateral resolution of 0.7 μm. Subsurface serial images at different depths (surface to 250 μm)were generated in real time at 1024 × 1024 pixels (0.8 frames/s) by placing the probe onto the tissue in gentle,stable contact. Tissue specimens were sampled for histopathological correlation.RESULTS: The esophagus, stomach, small and large intestine and meso, liver, pancreas and gall bladder were visualised in vivo at high resolution in n = 48 mice.Real time microscopic imaging with the confocal minimicroscopy probe was easy to achieve. The different staining protocols (fluorescein, acriflavine, FITC-labelled dextran and L. esculentum lectin) each highlighted specific aspects of the tissue, and in vivo imaging correlated excellently with conventional histology. In vivo blood flow monitoring added a functional quality to morphologic imaging.CONCLUSION: Confocal microscopy is feasible in vivo allowing the visualisation of the complete GI tract at high resolution even of subsurface tissue structures.The new confocal probe design evaluated in this study is compatible with laparoscopy and significantly expands the field of possible applications to intra-abdominal organs. It allows immediate testing of new in vivo staining and application options and therefore permits rapid transfer from animal studies to clinical use in patients.

Transforaminal Percutaneous Endoscopic Discectomy and Foraminoplasty after Lumbar Spinal Fusion Surgery.

Science.gov (United States)

Wu, Jian-Jun; Chen, Hui-Zhen; Zheng, Changkun

2017-07-01

The most common causes of pain following lumbar spinal fusions are residual herniation, or foraminal fibrosis and foraminal stenosis that is ignored, untreated, or undertreated. The original surgeon may advise his patient that nothing more can be done in his opinion that the nerve was visually decompressed by the original surgery. Post-operative imaging or electrophysiological assessment may be inadequate to explain all the reasons for residual or recurrent symptoms. Treatment of failed lumbar spinal fusions by repeat traditional open revision surgery usually incorporates more extensive decompression causing increased instability and back pain. The authors, having limited their practice to endoscopic surgery over the last 10 years, report on their experience gained during that period to relieve pain by transforaminal percutaneous endoscopic revision of lumbar spinal fusions. To assess the effectiveness of transforaminal percutaneous endoscopic discectomy and foraminoplasty in patients with pain after lumbar spinal fusion. Retrospective study. Inpatient surgery center. Sixteen consecutive patients with pain after lumbar spinal fusions presenting with back and leg pain that had supporting imaging diagnosis of foraminal stenosis and/or residual/recurrent disc herniation, or whose pain complaint was supported by relief from diagnostic and therapeutic injections, were offered percutaneous transforaminal endoscopic discectomy and foraminoplasty over a repeat open procedure. Each patient sought consultation following a transient successful, partially successful or unsuccessful open lumbar spinal fusions treatment for disc herniation or spinal stenosis. Endoscopic foraminoplasty was also performed to either decompress the bony foramen in the case of foraminal stenosis, or to allow for endoscopic visual examination of the affected traversing and exiting nerve roots in the axilla. The average follow-up time was 30.3 months, minimum 12 months. Outcome data at each visit

Location of disease on imaging may predict radiation exposure during endoscopic retrograde cholangiopancreatography

International Nuclear Information System (INIS)

Choi, Moon Hyung; Jung, Seung Eun; Yoon, Seung Bae; Lee, In Seokand; Byun, Jae Young

2017-01-01

Endoscopic retrograde cholangiopancreatography (ERCP) is performed for various diseases. The aim of this study is to evaluate the difference of dose-area product (DAP) during the ERCP procedures according to location of the lesion. We performed a retrospective study of consecutive 217 therapeutic ERCP examinations performed between November 2014 and April 2015 at a tertiary care center. ERCP procedures divided into two groups according to location of the lesion identified on imaging: lesions in the common hepatic duct (CHD) or the common bile duct (CBD) and lesions in the hepatic hilum or the intrahepatic duct (IHD). The mean DAP of the hilum-IHD group (48.7 Gy cm 2 ) was significantly higher than that of the CBD-CHD group (34.9 Gy cm 2 ) (P = 0.003). Radiation exposure during ERCP was significantly different according to location of bile duct lesion. (authors)

Video-based measurements for wireless capsule endoscope tracking

International Nuclear Information System (INIS)

Spyrou, Evaggelos; Iakovidis, Dimitris K

2014-01-01

The wireless capsule endoscope is a swallowable medical device equipped with a miniature camera enabling the visual examination of the gastrointestinal (GI) tract. It wirelessly transmits thousands of images to an external video recording system, while its location and orientation are being tracked approximately by external sensor arrays. In this paper we investigate a video-based approach to tracking the capsule endoscope without requiring any external equipment. The proposed method involves extraction of speeded up robust features from video frames, registration of consecutive frames based on the random sample consensus algorithm, and estimation of the displacement and rotation of interest points within these frames. The results obtained by the application of this method on wireless capsule endoscopy videos indicate its effectiveness and improved performance over the state of the art. The findings of this research pave the way for a cost-effective localization and travel distance measurement of capsule endoscopes in the GI tract, which could contribute in the planning of more accurate surgical interventions. (paper)

Video-based measurements for wireless capsule endoscope tracking

Science.gov (United States)

Spyrou, Evaggelos; Iakovidis, Dimitris K.

2014-01-01

The wireless capsule endoscope is a swallowable medical device equipped with a miniature camera enabling the visual examination of the gastrointestinal (GI) tract. It wirelessly transmits thousands of images to an external video recording system, while its location and orientation are being tracked approximately by external sensor arrays. In this paper we investigate a video-based approach to tracking the capsule endoscope without requiring any external equipment. The proposed method involves extraction of speeded up robust features from video frames, registration of consecutive frames based on the random sample consensus algorithm, and estimation of the displacement and rotation of interest points within these frames. The results obtained by the application of this method on wireless capsule endoscopy videos indicate its effectiveness and improved performance over the state of the art. The findings of this research pave the way for a cost-effective localization and travel distance measurement of capsule endoscopes in the GI tract, which could contribute in the planning of more accurate surgical interventions.

High-spatial-resolution sub-surface imaging using a laser-based acoustic microscopy technique.

Science.gov (United States)

Balogun, Oluwaseyi; Cole, Garrett D; Huber, Robert; Chinn, Diane; Murray, Todd W; Spicer, James B

2011-01-01

Scanning acoustic microscopy techniques operating at frequencies in the gigahertz range are suitable for the elastic characterization and interior imaging of solid media with micrometer-scale spatial resolution. Acoustic wave propagation at these frequencies is strongly limited by energy losses, particularly from attenuation in the coupling media used to transmit ultrasound to a specimen, leading to a decrease in the depth in a specimen that can be interrogated. In this work, a laser-based acoustic microscopy technique is presented that uses a pulsed laser source for the generation of broadband acoustic waves and an optical interferometer for detection. The use of a 900-ps microchip pulsed laser facilitates the generation of acoustic waves with frequencies extending up to 1 GHz which allows for the resolution of micrometer-scale features in a specimen. Furthermore, the combination of optical generation and detection approaches eliminates the use of an ultrasonic coupling medium, and allows for elastic characterization and interior imaging at penetration depths on the order of several hundred micrometers. Experimental results illustrating the use of the laser-based acoustic microscopy technique for imaging micrometer-scale subsurface geometrical features in a 70-μm-thick single-crystal silicon wafer with a (100) orientation are presented.

An Entropy-Based Propagation Speed Estimation Method for Near-Field Subsurface Radar Imaging

Science.gov (United States)

Flores-Tapia, Daniel; Pistorius, Stephen

2010-12-01

During the last forty years, Subsurface Radar (SR) has been used in an increasing number of noninvasive/nondestructive imaging applications, ranging from landmine detection to breast imaging. To properly assess the dimensions and locations of the targets within the scan area, SR data sets have to be reconstructed. This process usually requires the knowledge of the propagation speed in the medium, which is usually obtained by performing an offline measurement from a representative sample of the materials that form the scan region. Nevertheless, in some novel near-field SR scenarios, such as Microwave Wood Inspection (MWI) and Breast Microwave Radar (BMR), the extraction of a representative sample is not an option due to the noninvasive requirements of the application. A novel technique to determine the propagation speed of the medium based on the use of an information theory metric is proposed in this paper. The proposed method uses the Shannon entropy of the reconstructed images as the focal quality metric to generate an estimate of the propagation speed in a given scan region. The performance of the proposed algorithm was assessed using data sets collected from experimental setups that mimic the dielectric contrast found in BMI and MWI scenarios. The proposed method yielded accurate results and exhibited an execution time in the order of seconds.

Epigastric hernia contiguous with the laparoscopic port site after endoscopic robotic total prostatectomy.

Science.gov (United States)

Moriwaki, Yoshihiro; Otani, Jun; Okuda, Junzo; Maemoto, Ryo

2018-03-23

Both laparoscopic and endoscopic robotic surgery are widely accepted for many abdominal surgeries. However, the port site for the laparoscope cannot be easily sutured without defect, particularly in the cranial end; this can result in a port-site incisional hernia and trigger the progressive thinning and stretching of the linea alba, leading to epigastric hernia. In the present case, we encountered an epigastric hernia contiguous with an incisional scar at the port site from a previous endoscopic robotic total prostatectomy. Abdominal ultrasound and CT revealed that the width of the linea alba was 30-48 mm. Previous CT images prepared before endoscopic robotic prostatectomy had shown a thinning of the linea alba. We should be aware of the possibility of epigastric hernia after laparoscopic and endoscopic robotic surgery. In laparoscopic and endoscopic robotic surgery for a high-risk patient for epigastric hernia, we should consider additional sutures cranial to the port-site incision to prevent of an epigastric hernia. © 2018 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

A hands-free region-of-interest selection interface for solo surgery with a wide-angle endoscope: preclinical proof of concept.

Science.gov (United States)

Jung, Kyunghwa; Choi, Hyunseok; Hong, Hanpyo; Adikrishna, Arnold; Jeon, In-Ho; Hong, Jaesung

2017-02-01

A hands-free region-of-interest (ROI) selection interface is proposed for solo surgery using a wide-angle endoscope. A wide-angle endoscope provides images with a larger field of view than a conventional endoscope. With an appropriate selection interface for a ROI, surgeons can also obtain a detailed local view as if they moved a conventional endoscope in a specific position and direction. To manipulate the endoscope without releasing the surgical instrument in hand, a mini-camera is attached to the instrument, and the images taken by the attached camera are analyzed. When a surgeon moves the instrument, the instrument orientation is calculated by an image processing. Surgeons can select the ROI with this instrument movement after switching from 'task mode' to 'selection mode.' The accelerated KAZE algorithm is used to track the features of the camera images once the instrument is moved. Both the wide-angle and detailed local views are displayed simultaneously, and a surgeon can move the local view area by moving the mini-camera attached to the surgical instrument. Local view selection for a solo surgery was performed without releasing the instrument. The accuracy of camera pose estimation was not significantly different between camera resolutions, but it was significantly different between background camera images with different numbers of features (P solo surgeries without a camera assistant.

Out-of-plane displacement measurement by means of endoscopic moire interferometry

International Nuclear Information System (INIS)

Martinez-Celorio, R.A.; Dirckx, Joris J.J.; Marti-Lopez, Luis; Pena-Lecona, Francisco G.

2004-01-01

An endoscopic moire technique is proposed for measuring out-of-plane displacements in difficult to reach places. The Ronchi grid is projected onto the tilted object with one endoscope with a 0 deg. viewing angle. The object with the projected grid is imaged by a second endoscope with a 30 deg. viewing angle onto a charge-coupled device. The captured images are stored in a PC, and are used to calculate the out-of-plane displacement of the object with a phase stepping technique. A computer generated grating method is used instead of a physical phase-shift device in the optical setup. This allows designing a set of three reference grids with profiles closely similar to the projected grating. The technique is robust against problems associated with the temporal shifting method, such as nonlinear phase shift and noise. To test the feasibility of the technique the measurement of out-of-plane displacements of about 35 μm of a latex membrane under deformation is demonstrated. The advantages and disadvantages are discussed

Subsurface imaging of water electrical conductivity, hydraulic permeability and lithology at contaminated sites by induced polarization

DEFF Research Database (Denmark)

Maurya, P. K.; Balbarini, Nicola; Møller, I.

2018-01-01

At contaminated sites, knowledge about geology and hydraulic properties of the subsurface and extent of the contamination is needed for assessing the risk and for designing potential site remediation. In this study, we have developed a new approach for characterizing contaminated sites through time...... geological logs. On average the IP-derived and measured permeability values agreed within one order of magnitude, except for those close to boundaries between lithological layers (e.g. between sand and clay), where mismatches occurred due to the lack of vertical resolution in the geophysical imaging...

Sonographic and Endoscopic Findings in Cocaine-Induced Ischemic Colitis

DEFF Research Database (Denmark)

Leth, Thomas; Wilkens, Rune; Bonderup, Ole Kristian

2015-01-01

Cocaine-induced ischemic colitis is a recognized entity. The diagnosis is based on clinical and endoscopic findings. However, diagnostic imaging is helpful in the evaluation of abdominal symptoms and prior studies have suggested specific sonographic findings in ischemic colitis. We report...

Ma_MISS on ExoMars: Mineralogical Characterization of the Martian Subsurface

Science.gov (United States)

De Sanctis, Maria Cristina; Altieri, Francesca; Ammannito, Eleonora; Biondi, David; De Angelis, Simone; Meini, Marco; Mondello, Giuseppe; Novi, Samuele; Paolinetti, Riccardo; Soldani, Massimo; Mugnuolo, Raffaele; Pirrotta, Simone; Vago, Jorge L.; Ma_MISS Team

2017-07-01

The Ma_MISS (Mars Multispectral Imager for Subsurface Studies) experiment is the visible and near infrared (VNIR) miniaturized spectrometer hosted by the drill system of the ExoMars 2020 rover. Ma_MISS will perform IR spectral reflectance investigations in the 0.4-2.2 μm range to characterize the mineralogy of excavated borehole walls at different depths (between 0 and 2 m). The spectral sampling is about 20 nm, whereas the spatial resolution over the target is 120 μm. Making use of the drill's movement, the instrument slit can scan a ring and build up hyperspectral images of a borehole. The main goal of the Ma_MISS instrument is to study the martian subsurface environment. Access to the martian subsurface is crucial to our ability to constrain the nature, timing, and duration of alteration and sedimentation processes on Mars, as well as habitability conditions. Subsurface deposits likely host and preserve H2O ice and hydrated materials that will contribute to our understanding of the H2O geochemical environment (both in the liquid and in the solid state) at the ExoMars 2020 landing site. The Ma_MISS spectral range and sampling capabilities have been carefully selected to allow the study of minerals and ices in situ before the collection of samples. Ma_MISS will be implemented to accomplish the following scientific objectives: (1) determine the composition of subsurface materials, (2) map the distribution of subsurface H2O and volatiles, (3) characterize important optical and physical properties of materials (e.g., grain size), and (4) produce a stratigraphic column that will inform with regard to subsurface geological processes. The Ma_MISS findings will help to refine essential criteria that will aid in our selection of the most interesting subsurface formations from which to collect samples.

SHUTTLE IMAGING RADAR: PHYSICAL CONTROLS ON SIGNAL PENETRATION AND SUBSURFACE SCATTERING IN THE EASTERN SAHARA.

Science.gov (United States)

Schaber, Gerald G.; McCauley, John F.; Breed, Carol S.; Olhoeft, Gary R.

1986-01-01

It is found that the Shuttle Imaging Radar A (SIR-A) signal penetration and subsurface backscatter within the upper meter or so of the sediment blanket in the Eastern Sahara of southern Egypt and northern Sudan are enhanced both by radar sensor parameters and by the physical and chemical characteristics of eolian and alluvial materials. The near-surface stratigraphy, the electrical properties of materials, and the types of radar interfaces found to be responsible for different classes of SIR-A tonal response are summarized. The dominant factors related to efficient microwave signal penetration into the sediment blanket include 1) favorable distribution of particle sizes, 2) extremely low moisture content and 3) reduced geometric scattering at the SIR-A frequency (1. 3 GHz). The depth of signal penetration that results in a recorded backscatter, called radar imaging depth, was documented in the field to be a maximum of 1. 5 m, or 0. 25 times the calculated skin depth, for the sediment blanket. The radar imaging depth is estimated to be between 2 and 3 m for active sand dune materials.

More noise, please: How cultural overprinting in the urban environment can be exploited for improved subsurface imaging (Invited)

Science.gov (United States)

Weiss, C. J.

2009-12-01

A long standing issue for geophysical imaging methods revolves around the proper treatment of "noise": Defining what noise is; separating "noise" for "signal"; filtering and suppressing noise; and recently, challenging the prevailing view that noise is a nuisance to see if, instead, it may contribute favorably toward improving subsurface imaging fidelity. This last point is particularly relevant to geophysical imaging in the urban environment where noise sources are abundant, complex, and logistical constraints on geophysical field procedures prohibit a crude "turning up the volume" approach to simply drown out the noise with powerful sources of electromagnetic and seismic energy. In this contribution I explore the concept passive geophysical imaging which uses uncorrelated ambient noise as the source of geophysical imaging energy to be used in the urban environment. Examples will be presented from seismic and ground penetrating radar methods, in addition to new theoretical results bearing on the feasibility of low-frequency electromagnetic induction techniques.

Dune advance into a coastal forest, equatorial Brazil: A subsurface perspective

Science.gov (United States)

Buynevich, Ilya V.; Filho, Pedro Walfir M. Souza; Asp, Nils E.

2010-06-01

A large active parabolic dune along the coast of Pará State, northern Brazil, was analyzed using aerial photography and imaged with high-resolution ground-penetrating radar (GPR) to map the subsurface facies architecture and point-source anomalies. Most high-amplitude (8-10 dB) subsurface anomalies are correlated with partially buried mangrove trees along the leading edge (slipface) of the advancing dune. Profiles along a 200-m long basal stoss side of the dune reveal 66 targets, most of which lie below the water table and are thus inaccessible by other methods. Signal amplitudes of point-source anomalies are substantially higher than those associated with the reflections from continuous subsurface features (water table, sedimentary layers). When complemented with exposures and excavations, GPR provides the best means of rapid continuous imaging of the geological record of complex interactions between vegetation and aeolian deposition.

Applications of electrical resistance tomography to subsurface environmental restoration

Energy Technology Data Exchange (ETDEWEB)

Ramirez, A.L. [Lawrence Livermore National Lab., CA (United States); Daily, W.D.

1994-11-15

We are developing a new imaging technique, Electrical Resistance Tomography (ERT), to map subsurface liquids as flow occurs during natural or clean-up processes and to map geologic structure. Natural processes (such as surface water infiltrating the vadose zone) and man-induced processes (such as tank leaks and clean-up processes such as steam injection), can create changes in a soil`s electrical properties that are readily measured. We have conducted laboratory and a variety of field experiments to investigate the capabilities and limitations of ERT for imaging underground structures and processes. In the last four years we have used ERT to successfully monitor several field processes including: a subsurface steam injection process (for VOC removal), an air injection process (below the water table) for VOC removal, water infiltration through the vadose zone, radio-frequency heating, ohmic heating, and tank and pond leaks. The information derived from ERT can be used by remediation projects to: detect and locate leaks, determine the effectiveness of clean-up processes, select appropriate clean-up alternatives, and to verify the installation and performance of subsurface barriers.

Successful Gastric Volvulus Reduction and Gastropexy Using a Dual Endoscope Technique

Directory of Open Access Journals (Sweden)

Laith H. Jamil

2014-01-01

Full Text Available Gastric volvulus is a life threatening condition characterized by an abnormal rotation of the stomach around an axis. Although the first line treatment of this disorder is surgical, we report here a case of gastric volvulus that was endoscopically managed using a novel strategy. An 83-year-old female with a history of pancreatic cancer status postpylorus-preserving Whipple procedure presented with a cecal volvulus requiring right hemicolectomy. Postoperative imaging included a CT scan and upper GI series that showed a gastric volvulus with the antrum located above the diaphragm. An upper endoscopy was advanced through the pylorus into the duodenum and left in this position to keep the stomach under the diaphragm. A second pediatric endoscope was advanced alongside and used to complete percutaneous endoscopic gastrostomy (PEG placement for anterior gastropexy. The patient’s volvulus resolved and there were no complications. From our review of the literature, the dual endoscopic technique employed here has not been previously described. Patients who are poor surgical candidates or those who do not require emergent surgery can possibly benefit the most from similar minimally invasive endoscopic procedures as described here.

Subsurface geometry of the San Andreas fault in southern California: Results from the Salton Seismic Imaging Project (SSIP) and strong ground motion expectations

Science.gov (United States)

Fuis, Gary S.; Bauer, Klaus; Goldman, Mark R.; Ryberg, Trond; Langenheim, Victoria; Scheirer, Daniel S.; Rymer, Michael J.; Stock, Joann M.; Hole, John A.; Catchings, Rufus D.; Graves, Robert; Aagaard, Brad T.

2017-01-01

The San Andreas fault (SAF) is one of the most studied strike‐slip faults in the world; yet its subsurface geometry is still uncertain in most locations. The Salton Seismic Imaging Project (SSIP) was undertaken to image the structure surrounding the SAF and also its subsurface geometry. We present SSIP studies at two locations in the Coachella Valley of the northern Salton trough. On our line 4, a fault‐crossing profile just north of the Salton Sea, sedimentary basin depth reaches 4 km southwest of the SAF. On our line 6, a fault‐crossing profile at the north end of the Coachella Valley, sedimentary basin depth is ∼2–3  km">∼2–3  km and centered on the central, most active trace of the SAF. Subsurface geometry of the SAF and nearby faults along these two lines is determined using a new method of seismic‐reflection imaging, combined with potential‐field studies and earthquakes. Below a 6–9 km depth range, the SAF dips ∼50°–60°">∼50°–60° NE, and above this depth range it dips more steeply. Nearby faults are also imaged in the upper 10 km, many of which dip steeply and project to mapped surface fault traces. These secondary faults may join the SAF at depths below about 10 km to form a flower‐like structure. In Appendix D, we show that rupture on a northeast‐dipping SAF, using a single plane that approximates the two dips seen in our study, produces shaking that differs from shaking calculated for the Great California ShakeOut, for which the southern SAF was modeled as vertical in most places: shorter‐period (TTfault.

Virtual endoscopy combined with intraoperative neuronavigation for planning of endoscopic surgery in patients with occlusive hydrocephalus and intracranial cysts

International Nuclear Information System (INIS)

Krombach, G.A.; Haage, P.; Kilbinger, M.; Rohde, V.; Struffert, T.; Thron, A.

2002-01-01

We assessed the clinical value of MR ventriculoscopy (virtual endoscopy, VE) combined with image-guided frameless stereotaxy for endoscopic surgery of occlusive hydrocephalus and intracranial cysts. VE was obtained in 20 patients with hydrocephalus and three with intracranial cysts. All surgical operations were endoscopic. The path of the rigid endoscope to the target point was planned using neuronavigation. VE was carried out along the same trajectory retrospectively in 20 cases and prospectively in three. The results were analysed for demonstration of anatomical landmarks and structures at risk. VE was successful in all patients. Possible obstacles to endoscopic access to the lamina terminalis and the basal cisterns and structures at risk, such as the basilar artery, were clearly shown in relation to the direction of the endoscope. However, the floor of the third ventricle and septum pellucidum were not clearly seen and possible abnormalities could therefore not be appreciated. VE can provide realistic simulation of endoscopic third ventriculostomy and cystostomy. The appropriate trepanation point and trajectory of the endoscope can be assessed with regard to the size of the foramen of Monro and the position of vulnerable structures. This simulated trajectory can be adapted to the field of operation by image-guided neuronavigation. This regime may potentially reduce the risk of damage to intracranial structures. (orig.)

Current Innovations in Endoscopic Therapy for the Management of Colorectal Cancer: From Endoscopic Submucosal Dissection to Endoscopic Full-Thickness Resection

Directory of Open Access Journals (Sweden)

Shintaro Fujihara

2014-01-01

Full Text Available Endoscopic submucosal dissection (ESD is accepted as a minimally invasive treatment for colorectal cancer. However, due to technical difficulties and an increased rate of complications, ESD is not widely used in the colorectum. In some cases, endoscopic treatment alone is insufficient for disease control, and laparoscopic surgery is required. The combination of laparoscopic surgery and endoscopic resection represents a new frontier in cancer treatment. Recent developments in advanced polypectomy and minimally invasive surgical techniques will enable surgeons and endoscopists to challenge current practice in colorectal cancer treatment. Endoscopic full-thickness resection (EFTR of the colon offers the potential to decrease the postoperative morbidity and mortality associated with segmental colectomy while enhancing the diagnostic yield compared to current endoscopic techniques. However, closure is necessary after EFTR and natural transluminal endoscopic surgery (NOTES. Innovative methods and new devices for EFTR and suturing are being developed and may potentially change traditional paradigms to achieve minimally invasive surgery for colorectal cancer. The present paper aims to discuss the complementary role of ESD and the future development of EFTR. We focus on the possibility of achieving EFTR using the ESD method and closing devices.

Experimental transapical endoscopic ventricular visualization and mitral repair.

Science.gov (United States)

Ruttkay, Tamas; Czesla, Markus; Nagy, Henrietta; Götte, Julia; Baksa, Gabor; Patonay, Lajos; Doll, Nicolas; Galajda, Zoltan

2015-04-01

An increasing number of experimental beating heart animal studies describe simple transapical mitral valve repairs based on the direct endoscopic visualization of the left ventricle. The aim of our human cadaveric study was to develop a method for more complex transapical endoscopic procedures by on-pump heart operations. After preparation of 20 human fresh cadavers, a standard left anterolateral minithoracotomy was performed in the fifth intercostal space and the pericardium was entered. A rigid 0 degree endoscope and the instruments were introduced through a silicon apical port. To restore the natural form of the left heart, CO2 was insufflated. To test the mitral valve competence, the left ventricle was pressure-injected with saline after each step. After transecting the chords of the A2 segment of the anterior mitral leaflet before the experimental mitral valve repair, the tendinous chord was replaced using an especially designed clip chord. The second part of the experiment consisted of a segmental excision of the P2 segment of the posterior mitral leaflet followed by a standard valvuloplasty and suture annuloplasty. With the help of the described transapical endoscopic mitral valve repair technique, we gained direct visual information of the coaptation line of the mitral leaflets as well as the anatomy and function of the subvalvular apparatus. Using intracardiac imaging, we could perform successful transapical complex mitral repair in each case. The minimally invasive transapical endoscopic method has the potential to offer advantages for on-pump mitral valve repair procedures even in complex mitral valve repair cases. Georg Thieme Verlag KG Stuttgart · New York.

An Innovate Robotic Endoscope Guidance System for Transnasal Sinus and Skull Base Surgery: Proof of Concept.

Science.gov (United States)

Friedrich, D T; Sommer, F; Scheithauer, M O; Greve, J; Hoffmann, T K; Schuler, P J

2017-12-01

Objective  Advanced transnasal sinus and skull base surgery remains a challenging discipline for head and neck surgeons. Restricted access and space for instrumentation can impede advanced interventions. Thus, we present the combination of an innovative robotic endoscope guidance system and a specific endoscope with adjustable viewing angle to facilitate transnasal surgery in a human cadaver model. Materials and Methods  The applicability of the robotic endoscope guidance system with custom foot pedal controller was tested for advanced transnasal surgery on a fresh frozen human cadaver head. Visualization was enabled using a commercially available endoscope with adjustable viewing angle (15-90 degrees). Results  Visualization and instrumentation of all paranasal sinuses, including the anterior and middle skull base, were feasible with the presented setup. Controlling the robotic endoscope guidance system was effectively precise, and the adjustable endoscope lens extended the view in the surgical field without the common change of fixed viewing angle endoscopes. Conclusion  The combination of a robotic endoscope guidance system and an advanced endoscope with adjustable viewing angle enables bimanual surgery in transnasal interventions of the paranasal sinuses and the anterior skull base in a human cadaver model. The adjustable lens allows for the abandonment of fixed-angle endoscopes, saving time and resources, without reducing the quality of imaging.

High Resolution Sub-MM Fiberoptic Endoscope Final Report CRADA No. TSB-1447-97

Energy Technology Data Exchange (ETDEWEB)

Stone, Gary F. [Univ. of California, Livermore, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Smith, John [CML Fiberoptics, Inc., Auburn, NY (United States)

2018-01-22

At the time of the CRADA, LLNL needed to develop a sub-mm outer diameter fiberoptic endoscope with 25pm or better resolution at 3-lOmm working distance to support the Enhanced Surveillance Program (ESP) and the Core Surveillance Program for DOE. The commercially available systems did not meet the image resolution requirements and development work was needed to reach three goals. We also needed to perform preliminary investigations into the production of such an endoscope with a steerable-articulated distal end. The goal of such an endoscope was to allow for a 45 degree inspection cone including the lens field of view.

Endoscopic third ventriculostomy

Directory of Open Access Journals (Sweden)

Yad Ram Yadav

2012-01-01

Full Text Available Endoscopic third ventriculostomy (ETV is considered as a treatment of choice for obstructive hydrocephalus. It is indicated in hydrocephalus secondary to congenital aqueductal stenosis, posterior third ventricle tumor, cerebellar infarct, Dandy-Walker malformation, vein of Galen aneurism, syringomyelia with or without Chiari malformation type I, intraventricular hematoma, post infective, normal pressure hydrocephalus, myelomeningocele, multiloculated hydrocephalus, encephalocele, posterior fossa tumor and craniosynostosis. It is also indicated in block shunt or slit ventricle syndrome. Proper Pre-operative imaging for detailed assessment of the posterior communicating arteries distance from mid line, presence or absence of Liliequist membrane or other membranes, located in the prepontine cistern is useful. Measurement of lumbar elastance and resistance can predict patency of cranial subarachnoid space and complex hydrocephalus, which decides an ultimate outcome. Water jet dissection is an effective technique of ETV in thick floor. Ultrasonic contact probe can be useful in selected patients. Intra-operative ventriculo-stomography could help in confirming the adequacy of endoscopic procedure, thereby facilitating the need for shunt. Intraoperative observations of the patent aqueduct and prepontine cistern scarring are predictors of the risk of ETV failure. Such patients may be considered for shunt surgery. Magnetic resonance ventriculography and cine phase contrast magnetic resonance imaging are effective in assessing subarachnoid space and stoma patency after ETV. Proper case selection, post-operative care including monitoring of ICP and need for external ventricular drain, repeated lumbar puncture and CSF drainage, Ommaya reservoir in selected patients could help to increase success rate and reduce complications. Most of the complications develop in an early post-operative, but fatal complications can develop late which indicate an importance of

Combining endoscopic ultrasound with Time-Of-Flight PET: The EndoTOFPET-US Project

CERN Document Server

Frisch, Benjamin

2013-01-01

The EndoTOFPET-US collaboration develops a multimodal imaging technique for endoscopic exams of the pancreas or the prostate. It combines the benefits of high resolution metabolic imaging with Time-Of-Flight Positron Emission Tomography (TOF PET) and anatomical imaging with ultrasound (US). EndoTOFPET-US consists of a PET head extension for a commercial US endoscope and a PET plate outside the body in coincidence with the head. The high level of miniaturization and integration creates challenges in fields such as scintillating crystals, ultra-fast photo-detection, highly integrated electronics, system integration and image reconstruction. Amongst the developments, fast scintillators as well as fast and compact digital SiPMs with single SPAD readout are used to obtain the best coincidence time resolution (CTR). Highly integrated ASICs and DAQ electronics contribute to the timing performances of EndoTOFPET. In view of the targeted resolution of around 1 mm in the reconstructed image, we present a prototype dete...

A standardised protocol for texture feature analysis of endoscopic images in gynaecological cancer

Directory of Open Access Journals (Sweden)

Pattichis Marios S

2007-11-01

Full Text Available Abstract Background In the development of tissue classification methods, classifiers rely on significant differences between texture features extracted from normal and abnormal regions. Yet, significant differences can arise due to variations in the image acquisition method. For endoscopic imaging of the endometrium, we propose a standardized image acquisition protocol to eliminate significant statistical differences due to variations in: (i the distance from the tissue (panoramic vs close up, (ii difference in viewing angles and (iii color correction. Methods We investigate texture feature variability for a variety of targets encountered in clinical endoscopy. All images were captured at clinically optimum illumination and focus using 720 × 576 pixels and 24 bits color for: (i a variety of testing targets from a color palette with a known color distribution, (ii different viewing angles, (iv two different distances from a calf endometrial and from a chicken cavity. Also, human images from the endometrium were captured and analysed. For texture feature analysis, three different sets were considered: (i Statistical Features (SF, (ii Spatial Gray Level Dependence Matrices (SGLDM, and (iii Gray Level Difference Statistics (GLDS. All images were gamma corrected and the extracted texture feature values were compared against the texture feature values extracted from the uncorrected images. Statistical tests were applied to compare images from different viewing conditions so as to determine any significant differences. Results For the proposed acquisition procedure, results indicate that there is no significant difference in texture features between the panoramic and close up views and between angles. For a calibrated target image, gamma correction provided an acquired image that was a significantly better approximation to the original target image. In turn, this implies that the texture features extracted from the corrected images provided for better

An Entropy-Based Propagation Speed Estimation Method for Near-Field Subsurface Radar Imaging

Directory of Open Access Journals (Sweden)

Pistorius Stephen

2010-01-01

Full Text Available During the last forty years, Subsurface Radar (SR has been used in an increasing number of noninvasive/nondestructive imaging applications, ranging from landmine detection to breast imaging. To properly assess the dimensions and locations of the targets within the scan area, SR data sets have to be reconstructed. This process usually requires the knowledge of the propagation speed in the medium, which is usually obtained by performing an offline measurement from a representative sample of the materials that form the scan region. Nevertheless, in some novel near-field SR scenarios, such as Microwave Wood Inspection (MWI and Breast Microwave Radar (BMR, the extraction of a representative sample is not an option due to the noninvasive requirements of the application. A novel technique to determine the propagation speed of the medium based on the use of an information theory metric is proposed in this paper. The proposed method uses the Shannon entropy of the reconstructed images as the focal quality metric to generate an estimate of the propagation speed in a given scan region. The performance of the proposed algorithm was assessed using data sets collected from experimental setups that mimic the dielectric contrast found in BMI and MWI scenarios. The proposed method yielded accurate results and exhibited an execution time in the order of seconds.

Endoscopic submucosal dissection

DEFF Research Database (Denmark)

Pimentel-Nunes, Pedro; Dinis-Ribeiro, Mário; Ponchon, Thierry

2015-01-01

evidence). 2 ESGE recommends endoscopic resection with a curative intent for visible lesions in Barrett's esophagus (strong recommendation, moderate quality evidence). ESD has not been shown to be superior to EMR for excision of mucosal cancer, and for that reason EMR should be preferred. ESD may...... RECOMMENDATIONS: 1 ESGE recommends endoscopic en bloc resection for superficial esophageal squamous cell cancers (SCCs), excluding those with obvious submucosal involvement (strong recommendation, moderate quality evidence). Endoscopic mucosal resection (EMR) may be considered in such lesions when...

Endoscopic Devices for Obesity.

Science.gov (United States)

Sampath, Kartik; Dinani, Amreen M; Rothstein, Richard I

2016-06-01

The obesity epidemic, recognized by the World Health Organization in 1997, refers to the rising incidence of obesity worldwide. Lifestyle modification and pharmacotherapy are often ineffective long-term solutions; bariatric surgery remains the gold standard for long-term obesity weight loss. Despite the reported benefits, it has been estimated that only 1% of obese patients will undergo surgery. Endoscopic treatment for obesity represents a potential cost-effective, accessible, minimally invasive procedure that can function as a bridge or alternative intervention to bariatric surgery. We review the current endoscopic bariatric devices including space occupying devices, endoscopic gastroplasty, aspiration technology, post-bariatric surgery endoscopic revision, and obesity-related NOTES procedures. Given the diverse devices already FDA approved and in development, we discuss the future directions of endoscopic therapies for obesity.

Gastric schwannomas: radiological features with endoscopic and pathological correlation

Energy Technology Data Exchange (ETDEWEB)

Hong, H.S. [Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seodaemoon-gu, Seoul (Korea, Republic of); Ha, H.K. [Department of Radiology, University of Ulsan College of Medicine, Songpa-gu, Seoul (Korea, Republic of)], E-mail: hkha@amc.seoul.kr; Won, H.J.; Byun, J.H.; Shin, Y.M.; Kim, A.Y.; Kim, P.N.; Lee, M.-G. [Department of Radiology, University of Ulsan College of Medicine, Songpa-gu, Seoul (Korea, Republic of); Lee, G.H. [Internal Medicine, University of Ulsan College of Medicine, Songpa-gu, Seoul (Korea, Republic of); Kim, M.J. [Pathology, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Seoul (Korea, Republic of)

2008-05-15

Aim: To describe the radiological, endoscopic, and pathological findings of gastric schwannomas in 16 patients. Materials and methods: The radiological, endoscopic, and pathological findings of 16 surgically proven cases of gastric schwannoma were retrospectively reviewed. All patients underwent computed tomography (CT) and four patients were evaluated with upper gastrointestinal series. Two radiologists reviewed the CT and upper gastrointestinal series images by consensus with regard to tumour size, contour, margin, and growth pattern, the presence or absence of ulcer, cystic change, and the CT enhancement pattern. Endoscopy was performed in eight of these 16 patients. Six patients underwent endoscopic ultrasonography. Pathological specimens were obtained from and reviewed in all 16 patients. Immunohistochemistry was performed for c-kit, CD34, smooth muscle actin, and S-100 protein. Results: On radiographic examination, gastric schwannomas appeared as submucosal tumours with the CT features of well-demarcated, homogeneous, and uncommonly ulcerated masses. Endoscopy with endoscopic ultrasonography demonstrated homogeneous, submucosal masses contiguous with the muscularis propria in all six examined cases. On pathological examination, gastric schwannomas appeared as well-circumscribed and homogeneous tumours in the muscularis propria and consisted microscopically of interlacing bundles of spindle cells. Strong positivity for S-100 protein was demonstrated in all 16 cases on immunohistochemistry. Conclusion: Gastric schwannomas appear as submucosal tumours of the stomach and have well-demarcated and homogeneous features on CT, endoscopic ultrasonography, and gross pathology. Immunohistochemistry consistently reveals positivity for S-100 protein in the tumours.

Gastric schwannomas: radiological features with endoscopic and pathological correlation

International Nuclear Information System (INIS)

Hong, H.S.; Ha, H.K.; Won, H.J.; Byun, J.H.; Shin, Y.M.; Kim, A.Y.; Kim, P.N.; Lee, M.-G.; Lee, G.H.; Kim, M.J.

2008-01-01

Aim: To describe the radiological, endoscopic, and pathological findings of gastric schwannomas in 16 patients. Materials and methods: The radiological, endoscopic, and pathological findings of 16 surgically proven cases of gastric schwannoma were retrospectively reviewed. All patients underwent computed tomography (CT) and four patients were evaluated with upper gastrointestinal series. Two radiologists reviewed the CT and upper gastrointestinal series images by consensus with regard to tumour size, contour, margin, and growth pattern, the presence or absence of ulcer, cystic change, and the CT enhancement pattern. Endoscopy was performed in eight of these 16 patients. Six patients underwent endoscopic ultrasonography. Pathological specimens were obtained from and reviewed in all 16 patients. Immunohistochemistry was performed for c-kit, CD34, smooth muscle actin, and S-100 protein. Results: On radiographic examination, gastric schwannomas appeared as submucosal tumours with the CT features of well-demarcated, homogeneous, and uncommonly ulcerated masses. Endoscopy with endoscopic ultrasonography demonstrated homogeneous, submucosal masses contiguous with the muscularis propria in all six examined cases. On pathological examination, gastric schwannomas appeared as well-circumscribed and homogeneous tumours in the muscularis propria and consisted microscopically of interlacing bundles of spindle cells. Strong positivity for S-100 protein was demonstrated in all 16 cases on immunohistochemistry. Conclusion: Gastric schwannomas appear as submucosal tumours of the stomach and have well-demarcated and homogeneous features on CT, endoscopic ultrasonography, and gross pathology. Immunohistochemistry consistently reveals positivity for S-100 protein in the tumours

Endoscopic management of biliary injuries and leaks

Directory of Open Access Journals (Sweden)

T S Chandrasekar

2012-01-01

Full Text Available Bile duct injuries and subsequent leaks can occur following laparoscopic and open cholecystectomies and also during other hepatobiliary surgeries. Various patient related and technical factors are implicated in the causation of biliary injuries. Over a period of twenty five years managing such patients of biliary injuries our team has found a practical approach to assess the cause of biliary injuries based on the symptoms, clinical examination and imaging. Bismuth classification is helpful in most of the cases. Immediate referral to a centre experienced in the management of bile duct injury and timely intervention is associated with improved outcomes. Resuscitation, correcting dyselectrolytemia, aspiration of undrained biloma and antibiotics take the priority in the management. The goal is to restore the bile conduit, and to prevent short and longterm complications such as biliary fistula, intra-abdominal abscess, biliary stricture, recurrent cholangitis and secondary biliary cirrhosis. Endoscopic therapy by reducing the transpapillary pressure gradient helps in reducing the leak. Endoscopic therapy with biliary sphincterotomy alone or with additional placement of a biliary stent/ nasobiliary drainage is advocated. In our tertiary care referral unit, we found endoscopic interventions are useful in situations where there is leak with associated CBD calculus or a foreign body, peripheral bile duct injury, cystic duct stump leak and partial bile duct injury with leak/ narrowing of the lumen. Endotherapy is not useful in case of complete transection (total cut off and complete stricture involving common hepatic or common bile ducts. In conclusion, endoscopic treatment can be considered a highly effective therapy and should be the first-line therapy in such patients. Though less successful, an endoscopic attempt is warranted in patients suffering from central bile duct leakages failing which surgical management is recommended.

Endoscopic middle ear exploration in pediatric patients with conductive hearing loss.

Science.gov (United States)

Carter, John M; Hoff, Stephen R

2017-05-01

To describe our indications, findings, and outcomes for transcanal endoscopic middle ear exploration in pediatric patients with conductive hearing loss of unknown etiology, without effusions. Prospective case series for all pediatric patients undergoing totally endoscopic transcanal middle ear exploration between April 2012 and October 2015 at a pediatric tertiary care referral hospital. Demographic data, operative findings, and hearing results were reviewed. 21 cases were performed in 20 ears (1 revision). Average age at surgery was 7.98 years and average follow up was 2.1 years. Middle ear pathology identified on CT imaging was confirmed in 55% of cases while identified in 45% of cases where pre-operative imaging was non-diagnostic. 6/20 patients (30%) had an ossicular deformity. 8/20(40%) had bony ossicular fixation. 5/20(25%) had ossicular discontinuity. 2/20(10%) had facial nerve dehiscence impinging on the stapes. 15% had adhesive myringosclerosis or severe granulation causing hearing loss. Prosthetic ossiculoplasty was done in 7/21 (33.3%) of the cases, with 1 TORP, 3 PORPs, and 3 IS joint replacements. Imaging was predictive of intra-operative findings in 13/20 cases (55%). Trainees assisted in 16/21(76%) of cases. The average improvement of PTA was 11.65 dB (range -10 to 36.25), and the average ABG improved 10.19 (range -11.25 to 28.75). There were no perioperative complications or adverse events. The endoscopic transcanal approach for middle ear exploration offers excellent visualization and is one of the best applications for the endoscopes in pediatric otology cases. This is particularly helpful for "unexplained" conductive hearing loss where ossicular deformity/fixation/discontinuity is suspected. The etiology of the conductive hearing loss was definitively found in 100% of cases, and can be repaired in the same sitting when applicable. Copyright © 2017 Elsevier B.V. All rights reserved.

Endoscopic management of colorectal adenomas.

Science.gov (United States)

Meier, Benjamin; Caca, Karel; Fischer, Andreas; Schmidt, Arthur

2017-01-01

Colorectal adenomas are well known precursors of invasive adenocarcinoma. Colonoscopy is the gold standard for adenoma detection. Colonoscopy is far more than a diagnostic tool, as it allows effective treatment of colorectal adenomas. Endoscopic resection of colorectal adenomas has been shown to reduce the incidence and mortality of colorectal cancer. Difficult resection techniques are available, such as endoscopic mucosal resection, endoscopic submucosal dissection and endoscopic full-thickness resection. This review aims to provide an overview of the different endoscopic resection techniques and their indications, and summarizes the current recommendations in the recently published guideline of the European Society of Gastrointestinal Endoscopy.

Sensitivity of endoscopic ultrasound, multidetector computed tomography, and magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a tertiary center experience.

Science.gov (United States)

Kushnir, Vladimir M; Wani, Sachin B; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris M; Mullady, Daniel K; Jonnalagadda, Sreenivasa S; Early, Dayna S; Edmundowicz, Steven A; Azar, Riad R

2013-04-01

There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: (1) evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP), and multidetector computed tomography (MDCT) for pancreas divisum; and (2) assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent endoscopic retrograde pancreatography and cross-sectional imaging. The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than the sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) (P pancreas divisum; IOA was moderate (κ = 0.43). Endoscopic ultrasound is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum.

Foot-controlled robotic-enabled endoscope holder for endoscopic sinus surgery: A cadaveric feasibility study.

Science.gov (United States)

Chan, Jason Y K; Leung, Iris; Navarro-Alarcon, David; Lin, Weiyang; Li, Peng; Lee, Dennis L Y; Liu, Yun-hui; Tong, Michael C F

2016-03-01

To evaluate the feasibility of a unique prototype foot-controlled robotic-enabled endoscope holder (FREE) in functional endoscopic sinus surgery. Cadaveric study. Using human cadavers, we investigated the feasibility, advantages, and disadvantages of the robotic endoscope holder in performing endoscopic sinus surgery with two hands in five cadaver heads, mimicking a single nostril three-handed technique. The FREE robot is relatively easy to use. Setup was quick, taking less than 3 minutes from docking the robot at the head of the bed to visualizing the middle meatus. The unit is also relatively small, takes up little space, and currently has four degrees of freedom. The learning curve for using the foot control was short. The use of both hands was not hindered by the presence of the endoscope in the nasal cavity. The tremor filtration also aided in the smooth movement of the endoscope, with minimal collisions. The FREE endoscope holder in an ex-vivo cadaver test corroborated the feasibility of the robotic prototype, which allows for a two-handed approach to surgery equal to a single nostril three-handed technique without the holder that may reduce operating time. Further studies will be needed to evaluate its safety profile and use in other areas of endoscopic surgery. NA. Laryngoscope, 126:566-569, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Learning endoscopic resection in the esophagus

NARCIS (Netherlands)

van Vilsteren, Frederike G. I.; Pouw, Roos E.; Herrero, Lorenza Alvarez; Bisschops, Raf; Houben, Martin; Peters, Frans T. M.; Schenk, B. E.; Weusten, Bas L. A. M.; Schoon, Erik J.; Bergman, Jacques J. G. H. M.

Background: Endoscopic resection is the cornerstone of endoscopic management of esophageal early neoplasia. However, endoscopic resection is a complex technique requiring knowledge and expertise. Our aims were to identify the most important learning points in performing endoscopic resection in a

Classification of atrophic mucosal patterns on Blue LASER Imaging for endoscopic diagnosis of Helicobacter pylori-related gastritis: A retrospective, observational study.

Science.gov (United States)

Nishikawa, Yoshiyuki; Ikeda, Yoshio; Murakami, Hidehiro; Hori, Shin-Ichiro; Hino, Kaori; Sasaki, Chise; Nishikawa, Megumi

2018-01-01

Atrophic gastritis can be classified according to characteristic mucosal patterns observed by Blue LASER Imaging (BLI) in a medium-range to distant view. To facilitate the endoscopic diagnosis of Helicobacter pylori (HP)-related gastritis, we investigated whether atrophic mucosal patterns correlated with HP infection based on the image interpretations of three endoscopists blinded to clinical features. This study included 441 patients diagnosed as having atrophic gastritis by upper gastrointestinal endoscopy at Nishikawa Gastrointestinal Clinic between April 1, 2015 and March 31, 2016. The presence/absence of HP infection was not taken into consideration. Endoscopy was performed using a Fujifilm EG-L580NW scope. Atrophic mucosal patterns observed by BLI were classified into Spotty, Cracked and Mottled. Image interpretation results were that 89, 122 and 228 patients had the Spotty, Cracked and Mottled patterns, respectively, and 2 patients an undetermined pattern. Further analyses were performed on 439 patients, excluding the 2 with undetermined patterns. The numbers of patients testing negative/positive for HP infection in the Spotty, Cracked and Mottled pattern groups were 12/77, 105/17, and 138/90, respectively. The specificity, positive predictive value and positive likelihood ratio for endoscopic diagnosis with positive HP infection based on the Spotty pattern were 95.3%, 86.5% and 8.9, respectively. In all patients with the Spotty pattern before HP eradication, the Cracked pattern was observed on subsequent post-eradication endoscopy. The Spotty pattern may represent the presence of HP infection, the Cracked pattern, a post-inflammatory change as seen after HP eradication, and the Mottled pattern, intestinal metaplasia.

A mobile laboratory for surface and subsurface imaging in geo-hazard monitoring activity

Science.gov (United States)

Cornacchia, Carmela; Bavusi, Massimo; Loperte, Antonio; Pergola, Nicola; Pignatti, Stefano; Ponzo, Felice; Lapenna, Vincenzo

2010-05-01

A new research infrastructure for supporting ground-based remote sensing observations in the different phases of georisk management cycle is presented. This instrumental facility has been designed and realised by TeRN, a public-private consortium on Earth Observations and Natural Risks, in the frame of the project "ImpresAmbiente" funded by Italian Ministry of Research and University. The new infrastructure is equipped with ground-based sensors (hyperspectral cameras, thermal cameras, laser scanning and electromagnetic antennae) able to remotely map physical parameters and/or earth-surface properties (temperature, soil moisture, land cover, etc…) and to illuminate near-surface geological structures (fault, groundwater tables, landslide bodies etc...). Furthermore, the system can be used for non-invasive investigations of architectonic buildings and civil infrastructures (bridges, tunnel, road pavements, etc...) interested by natural and man-made hazards. The hyperspectral cameras can acquire high resolution images of earth-surface and cultural objects. They are operating in the Visible Near InfraRed (0.4÷1.0μm) with 1600 spatial pixel and 3.7nm of spectral sampling and in the Short Wave InfraRed (1.3÷2.5µm) spectral region with 320 spatial pixel and 5nm of spectral sampling. The IR cameras are operating in the Medium Wavelength InfraRed (3÷5µm; 640x512; NETDcultural heritage. As a consequence, laser data can be useful integrated with traditional monitoring techniques. The Laser Scanner is characterized by very high data acquisition repetition rate up to 500.000 pxl/sec with a range resolution of 0.1 mm, vertical and horizontal FoV of 310° and 360° respectively with a resolution of 0.0018°. The system is also equipped with a metric camera allows to georeference the high resolution images acquired. The electromagnetic sensors allow to obtain in near real time high-resolution 2D and 3D subsurface tomographic images. The main components are a fully automatic

Peeking Beneath the Caldera: Communicating Subsurface Knowledge of Newberry Volcano

Science.gov (United States)

Mark-Moser, M.; Rose, K.; Schultz, J.; Cameron, E.

2016-12-01

"Imaging the Subsurface: Enhanced Geothermal Systems and Exploring Beneath Newberry Volcano" is an interactive website that presents a three-dimensional subsurface model of Newberry Volcano developed at National Energy Technology Laboratory (NETL). Created using the Story Maps application by ArcGIS Online, this format's dynamic capabilities provide the user the opportunity for multimedia engagement with the datasets and information used to build the subsurface model. This website allows for an interactive experience that the user dictates, including interactive maps, instructive videos and video capture of the subsurface model, and linked information throughout the text. This Story Map offers a general background on the technology of enhanced geothermal systems and the geologic and development history of Newberry Volcano before presenting NETL's modeling efforts that support the installation of enhanced geothermal systems. The model is driven by multiple geologic and geophysical datasets to compare and contrast results which allow for the targeting of potential EGS sites and the reduction of subsurface uncertainty. This Story Map aims to communicate to a broad audience, and provides a platform to effectively introduce the model to researchers and stakeholders.

The utility of high-resolution intraoperative MRI in endoscopic transsphenoidal surgery for pituitary macroadenomas: early experience in the Advanced Multimodality Image Guided Operating suite

Science.gov (United States)

Zaidi, Hasan A.; De Los Reyes, Kenneth; Barkhoudarian, Garni; Litvack, Zachary N.; Bi, Wenya Linda; Rincon-Torroella, Jordina; Mukundan, Srinivasan; Dunn, Ian F.; Laws, Edward R.

2016-01-01

Objective Endoscopic skull base surgery has become increasingly popular among the skull base surgery community, with improved illumination and angled visualization potentially improving tumor resection rates. Intraoperative MRI (iMRI) is used to detect residual disease during the course of the resection. This study is an investigation of the utility of 3-T iMRI in combination with transnasal endoscopy with regard to gross-total resection (GTR) of pituitary macroadenomas. Methods The authors retrospectively reviewed all endoscopic transsphenoidal operations performed in the Advanced Multimodality Image Guided Operating (AMIGO) suite from November 2011 to December 2014. Inclusion criteria were patients harboring presumed pituitary macroadenomas with optic nerve or chiasmal compression and visual loss, operated on by a single surgeon. Results Of the 27 patients who underwent transsphenoidal resection in the AMIGO suite, 20 patients met the inclusion criteria. The endoscope alone, without the use of iMRI, would have correctly predicted 13 (65%) of 20 cases. Gross-total resection was achieved in 12 patients (60%) prior to MRI. Intraoperative MRI helped convert 1 STR and 4 NTRs to GTRs, increasing the number of GTRs from 12 (60%) to 16 (80%). Conclusions Despite advances in visualization provided by the endoscope, the incidence of residual disease can potentially place the patient at risk for additional surgery. The authors found that iMRI can be useful in detecting unexpected residual tumor. The cost-effectiveness of this tool is yet to be determined. PMID:26926058

Simulation, image reconstruction and SiPM characterisation for a novel endoscopic positron emission tomography detector

Energy Technology Data Exchange (ETDEWEB)

Zvolsky, Milan

2017-12-15

In the scope of the EndoTOFPET-US project, a novel multimodal device for ultrasound (US) endoscopy and positron emission tomography (PET) is being developed. The project aims at detecting and quantifying morphologic and functional biomarkers and developing new biomarkers for pancreas and prostate oncology. The detector system comprises a small detector probe mounted on an ultrasound endoscope and an external detector plate. The detection of the gamma rays is realised by scintillator crystals with Silicon Photomultiplier (SiPM) read-out. For the characterisation of over 4000 SiPMs for the external plate, an automatised measurement and data analysis procedure is established. The key properties of the SiPMs like breakdown voltage and dark count rate (DCR) are extracted. This knowledge is needed both as a quality assurance as well as for the calibration of the detector. The spread between minimum and maximum breakdown voltage within a SiPM array of 4 x 4 is at maximum 0.43 V with a mean of 0.15 V and an RMS of 0.06 V. This assures the optimal biasing of each SiPM at its individual operating voltage. The mean DCR amounts to 1.49 MHz with an RMS of 0.54 MHz and is thus well below the acceptable threshold of 3 MHz. Two spare modules from the external plate are re-measured and analysed several years after the module assembly, revealing a potential alteration of the SiPM noise properties over time. For the characterisation of SiPMs from different vendors, a software framework for the automatic extraction of performance parameters from pulseheight spectra, including a t of the entire spectrum, is developed and tested. In order to facilitate the modelling of the response of the EndoTOFPET-US detector, a framework is developed which is built around the Geant4-based simulation toolkit GAMOS, to simulate and reconstruct realistic imaging scenarios with this asymmetric PET detector. The simulation studies are used to compare different possible detector designs, guide the

Simulation, image reconstruction and SiPM characterisation for a novel endoscopic positron emission tomography detector

International Nuclear Information System (INIS)

Zvolsky, Milan

2017-12-01

In the scope of the EndoTOFPET-US project, a novel multimodal device for ultrasound (US) endoscopy and positron emission tomography (PET) is being developed. The project aims at detecting and quantifying morphologic and functional biomarkers and developing new biomarkers for pancreas and prostate oncology. The detector system comprises a small detector probe mounted on an ultrasound endoscope and an external detector plate. The detection of the gamma rays is realised by scintillator crystals with Silicon Photomultiplier (SiPM) read-out. For the characterisation of over 4000 SiPMs for the external plate, an automatised measurement and data analysis procedure is established. The key properties of the SiPMs like breakdown voltage and dark count rate (DCR) are extracted. This knowledge is needed both as a quality assurance as well as for the calibration of the detector. The spread between minimum and maximum breakdown voltage within a SiPM array of 4 x 4 is at maximum 0.43 V with a mean of 0.15 V and an RMS of 0.06 V. This assures the optimal biasing of each SiPM at its individual operating voltage. The mean DCR amounts to 1.49 MHz with an RMS of 0.54 MHz and is thus well below the acceptable threshold of 3 MHz. Two spare modules from the external plate are re-measured and analysed several years after the module assembly, revealing a potential alteration of the SiPM noise properties over time. For the characterisation of SiPMs from different vendors, a software framework for the automatic extraction of performance parameters from pulseheight spectra, including a t of the entire spectrum, is developed and tested. In order to facilitate the modelling of the response of the EndoTOFPET-US detector, a framework is developed which is built around the Geant4-based simulation toolkit GAMOS, to simulate and reconstruct realistic imaging scenarios with this asymmetric PET detector. The simulation studies are used to compare different possible detector designs, guide the

Endoscopic visualization of luminal organ and great vessels with three dimensional CT scanner

International Nuclear Information System (INIS)

Kobayashi, Hisashi; Okumura, Toshiyuki; Amemiya, Ryuta; Hasegawa, Hiroshi

1992-01-01

Thirty cases examined by three dimensional CT scanner (3DCT) are reported. The observation of inner view using 3DCT were performed in 12 large vessels with vascular disorder, 10 pulmonary bronchi with lung cancer and 8 common bile ducts involved obstructive disease. In order to visualize interface of the lumen, a new software, which was developed by HITACHI MEDICO Inc., was used. In all cases but one the inner view of the luminal organ was clearly demonstrated as 3D images and it was possible to judge some changes of luminal interface involved by the diseases. The 3DCT endoscopic image might be useful as a new endoscopic technique without fiberscopy. (author)

Contrast-enhanced endoscopic ultrasonography in digestive diseases.

Science.gov (United States)

Hirooka, Yoshiki; Itoh, Akihiro; Kawashima, Hiroki; Ohno, Eizaburo; Itoh, Yuya; Nakamura, Yosuke; Hiramatsu, Takeshi; Sugimoto, Hiroyuki; Sumi, Hajime; Hayashi, Daijiro; Ohmiya, Naoki; Miyahara, Ryoji; Nakamura, Masanao; Funasaka, Kohei; Ishigami, Masatoshi; Katano, Yoshiaki; Goto, Hidemi

2012-10-01

Contrast-enhanced endoscopic ultrasonography (CE-EUS) was introduced in the early 1990s. The concept of the injection of carbon dioxide microbubbles into the hepatic artery as a contrast material (enhanced ultrasonography) led to "endoscopic ultrasonographic angiography". After the arrival of the first-generation contrast agent, high-frequency (12 MHz) EUS brought about the enhancement of EUS images in the diagnosis of pancreatico-biliary diseases, upper gastrointestinal (GI) cancer, and submucosal tumors. The electronic scanning endosonoscope with both radial and linear probes enabled the use of high-end ultrasound machines and depicted the enhancement of both color/power Doppler flow-based imaging and harmonic-based imaging using second-generation contrast agents. Many reports have described the usefulness of the differential diagnosis of pancreatic diseases and other abdominal lesions. Quantitative evaluation of CE-EUS images was an objective method of diagnosis using the time-intensity curve (TIC), but it was limited to the region of interest. Recently developed Inflow Time Mapping™ can be generated from stored clips and used to display the pattern of signal enhancement with time after injection, offering temporal difference of contrast agents and improved tumor characterization. On the other hand, three-dimensional CE-EUS images added new information to the literature, but lacked positional information. Three-dimensional CE-EUS with accurate positional information is awaited. To date, most reports have been related to pancreatic lesions or lymph nodes. Hemodynamic analysis might be of use for diseases in other organs: upper GI cancer diagnosis, submucosal tumors, and biliary disorders, and it might also provide functional information. Studies of CE-EUS in diseases in many other organs will increase in the near future.

Dosimetry in endoscopic examinations

International Nuclear Information System (INIS)

Aldred, Martha Aurelia; Paes, Walter Siqueira; Fausto, Agnes M.F.; Nucci, Jose Roberto; Yoshimura, Elisabeth Mateus; Okuno, Emico; Maruta, Luis Massuo

1996-01-01

Equivalent and effective doses in occupational exposures are evaluated considering that some specific endoscopic examinations, radiographic and fluoroscopic images of patients are taken with the medical staff near to the radiation field. Examinations are simulated using an anthropomorphic phantom as a member of the medical staff. Thermoluminescent dosemeters are attached in several positions of the phantom in order to determine some organ doses. From the comparison between the doses experimentally determined and the International and the Brazilian recommended occupational dose limits, the maximum number of examination that any member of the staff can perform was calculated

[Virtual bronchoscopy: the correlation between endoscopic simulation and bronchoscopic findings].

Science.gov (United States)

Salvolini, L; Gasparini, S; Baldelli, S; Bichi Secchi, E; Amici, F

1997-11-01

We carried out a preliminary clinical validation of 3D spiral CT virtual endoscopic reconstructions of the tracheobronchial tree, by comparing virtual bronchoscopic images with actual endoscopic findings. Twenty-two patients with tracheobronchial disease suspected at preliminary clinical, cytopathological and plain chest film findings were submitted to spiral CT of the chest and bronchoscopy. CT was repeated after endobronchial therapy in 2 cases. Virtual endoscopic shaded-surface-display views of the tracheobronchial tree were reconstructed from reformatted CT data with an Advantage Navigator software. Virtual bronchoscopic images were preliminarily evaluated with a semi-quantitative quality score (excellent/good/fair/poor). The depiction of consecutive airway branches was then considered. Virtual bronchoscopies were finally submitted to double-blind comparison with actual endoscopies. Virtual image quality was considered excellent in 8 cases, good in 14 and fair in 2. Virtual exploration was stopped at the lobar bronchi in one case only; the origin of segmental bronchi was depicted in 23 cases and that of some subsegmental branches in 2 cases. Agreement between actual and virtual bronchoscopic findings was good in all cases but 3 where it was nevertheless considered satisfactory. The yield of clinically useful information differed in 8/24 cases: virtual reconstructions provided more information than bronchoscopy in 5 cases and vice versa in 3. Virtual reconstructions are limited in that the procedure is long and difficult and needing a strictly standardized threshold value not to alter virtual findings. Moreover, the reconstructed surface lacks transparency, there is the partial volume effect and the branches < or = 4 pixels phi and/or meandering ones are difficult to explore. Our preliminary data are encouraging. Segmental bronchi were depicted in nearly all cases, except for the branches involved by disease. Obstructing lesions could be bypassed in some cases

Endoscopic submucosal dissection for locally recurrent colorectal lesions after previous endoscopic mucosal resection.

Science.gov (United States)

Zhou, Pinghong; Yao, Liqing; Qin, Xinyu; Xu, Meidong; Zhong, Yunshi; Chen, Weifeng

2009-02-01

The objective of this study was to determine the efficacy and safety of endoscopic submucosal dissection for locally recurrent colorectal cancer after previous endoscopic mucosal resection. A total of 16 patients with locally recurrent colorectal lesions were enrolled. A needle knife, an insulated-tip knife and a hook knife were used to resect the lesion along the submucosa. The rate of the curative resection, procedure time, and incidence of complications were evaluated. Of 16 lesions, 15 were completely resected with endoscopic submucosal dissection, yielding an en bloc resection rate of 93.8 percent. Histologic examination confirmed that lateral and basal margins were cancer-free in 14 patients (87.5 percent). The average procedure time was 87.2 +/- 60.7 minutes. None of the patients had immediate or delayed bleeding during or after endoscopic submucosal dissection. Perforation in one patient (6.3 percent) was the only complication and was managed conservatively. The mean follow-up period was 15.5 +/- 6.8 months; none of the patients experienced lesion residue or recurrence. Endoscopic submucosal dissection appears to be effective for locally recurrent colorectal cancer after previous endoscopic mucosal resection, making it possible to resect whole lesions and provide precise histologic information.

Endoscopic Laser-Based 3D Imaging for Functional Voice Diagnostics

Directory of Open Access Journals (Sweden)

Marion Semmler

2017-06-01

Full Text Available Recently, we reported on the in vivo application of a miniaturized measuring device for 3D visualization of the superior vocal fold vibrations from high-speed recordings in combination with a laser projection unit (LPU. As a long-term vision for this proof of principle, we strive to integrate the further developed laserendoscopy as a diagnostic method in daily clinical routine. The new LPU mainly comprises a Nd:YAG laser source (532 nm/CW/2 ω and a diffractive optical element (DOE generating a regular laser grid (31 × 31 laser points that is projected on the vocal folds. By means of stereo triangulation, the 3D coordinates of the laser points are reconstructed from the endoscopic high-speed footage. The new design of the laserendoscope constitutes a compromise between robust image processing and laser safety regulations. The algorithms for calibration and analysis are now optimized with respect to their overall duration and the number of required interactions, which is objectively assessed using binary classifiers. The sensitivity and specificity of the calibration procedure are increased by 40.1% and 22.3%, which is statistically significant. The overall duration for the laser point detection is reduced by 41.9%. The suggested semi-automatic reconstruction software represents an important stepping-stone towards potential real time processing and a comprehensive, objective diagnostic tool of evidence-based medicine.

Endoscopic case

Directory of Open Access Journals (Sweden)

Fernando Pereira

2017-01-01

Full Text Available We present the case of a ten-year-old female patient referred to Gastroenterolgy consultation for abdominal pain and cramping, usually worse after eating, recurring diarrhoea, hypochromic and microcytic anaemia with low serum iron and ferritin levels. Moderate to severe Crohn’s disease of the terminal ileum e right colon (L3 was diagnosed, based on endoscopic image and biopsy. The patient was treated with prednisone and azathioprine, but after one year of treatment she was steroids dependent and treatment was switched to infliximab. One year after beginning this treatment, the patient achieved remission (clinical and laboratorial parameters. A control colonoscopy showed mucosal healing with scars and deformation with stenosis of ileocecal valve (Figures 1-2. Surgical intervention will be probably necessary in near future.

Contrast-enhanced harmonic endoscopic ultrasound

DEFF Research Database (Denmark)

Săftoiu, A; Dietrich, C F; Vilmann, P

2012-01-01

Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, and improving staging and guidance of therapeutic procedures. Although...... initially used as Doppler signal enhancers, second-generation microbubble contrast agents are now used with specific contrast harmonic imaging techniques, which benefit from the highly nonlinear behavior of the microbubbles. Contrast-specific modes based on multi-pulse technology are used to perform...... contrast-enhanced harmonic EUS based on a very low mechanical index (0.08 - 0.12). Quantification techniques based on dynamic contrast-enhanced ultrasound have been recommended for perfusion imaging and monitoring of anti-angiogenic treatment, mainly based on time-intensity curve analysis. Most...

Creating Panoramic Images for Bladder Fluorescence Endoscopy

Directory of Open Access Journals (Sweden)

A. Behrens

2008-01-01

Full Text Available The medical diagnostic analysis and therapy of urinary bladder cancer based on endoscopes are state of the art in urological medicine. Due to the limited field of view of endoscopes, the physician can examine only a small part of the whole operating field at once. This constraint makes visual control and navigation difficult, especially in hollow organs. A panoramic image, covering a larger field of view, can overcome this difficulty. Directly motivated by a physician we developed an image mosaicing algorithm for endoscopic bladder fluorescence video sequences. In this paper, we present an approach which is capable of stitching single endoscopic video images to a combined panoramic image. Based on SIFT features we estimate a 2-D homography for each image pair, using an affine model and an iterative model-fitting algorithm. We then apply the stitching process and perform a mutual linear interpolation. Our panoramic image results show a correct stitching and lead to a better overview and understanding of the operation field. 

Sub-surface defect detection using transient thermography

International Nuclear Information System (INIS)

Mohd Zaki Umar; Huda Abdullah; Abdul Razak Hamzah; Wan Saffiey Wan Abdullah; Ibrahim Ahmad; Vavilov, Vladimir

2009-04-01

An experimental research had been carried out to study the potential of transient thermography in detecting sub-surface defect of non-metal material. In this research, eight pieces of bakelite material were used as samples. Each samples had a sub-surface defect in the circular shape with different diameters and depths. Experiment was conducted using one-sided Pulsed Thermal technique. Heating of samples were done using 30 k Watt adjustable quartz lamp while infra red (IR) images of samples were recorded using THV 550 IR camera. These IR images were then analysed with thermo fit TM Pro software to obtain the Maximum Absolute Differential Temperature Signal value, ΔT max and the time of its appearance, τ max (ΔT). Result showed that all defects were able to be detected even for the smallest and deepest defect (diameter = 5 mm and depth = 4 mm). However the highest value of Differential Temperature Signal (ΔT max ), were obtained at defect with the largest diameter, 20 mm and at the shallowest depth, 1 mm. As a conclusion, the sensitivity of the pulsed thermography technique to detect sub-surface defects of bakelite material is proportionately related with the size of defect diameter if the defect area at the same depth. On the contrary, the sensitivity of the pulsed thermography technique inversely related with the depth of defect if the defects have similar diameter size. (author)

Endoscopic therapy of neoplasia related to Barrett's esophagus and endoscopic palliation of esophageal cancer.

Science.gov (United States)

Vignesh, Shivakumar; Hoffe, Sarah E; Meredith, Kenneth L; Shridhar, Ravi; Almhanna, Khaldoun; Gupta, Akshay K

2013-04-01

Barrett's esophagus (BE) is the most important identifiable risk factor for the progression to esophageal adenocarcinoma. This article reviews the current endoscopic therapies for BE with high-grade dysplasia and intramucosal cancer and briefly discusses the endoscopic palliation of advanced esophageal cancer. The diagnosis of low-grade or high-grade dysplasia (HGD) is based on several cytologic criteria that suggest neoplastic transformation of the columnar epithelium. HGD and carcinoma in situ are regarded as equivalent. The presence of dysplasia, particularly HGD, is also a risk factor for synchronous and metachronous adenocarcinoma. Dysplasia is a marker of adenocarcinoma and also has been shown to be the preinvasive lesion. Esophagectomy has been the conventional treatment for T1 esophageal cancer and, although debated, is an appropriate option in some patients with HGD due to the presence of occult cancer in over one-third of patients. Endoscopic ablative modalities (eg, photodynamic therapy and cryoablation) and endoscopic resection techniques (eg, endoscopic mucosal resection) have demonstrated promising results. The significant morbidity and mortality of esophagectomy makes endoscopic treatment an attractive potential option.

An Automated Self-Learning Quantification System to Identify Visible Areas in Capsule Endoscopy Images.

Science.gov (United States)

Hashimoto, Shinichi; Ogihara, Hiroyuki; Suenaga, Masato; Fujita, Yusuke; Terai, Shuji; Hamamoto, Yoshihiko; Sakaida, Isao

2017-08-01

Visibility in capsule endoscopic images is presently evaluated through intermittent analysis of frames selected by a physician. It is thus subjective and not quantitative. A method to automatically quantify the visibility on capsule endoscopic images has not been reported. Generally, when designing automated image recognition programs, physicians must provide a training image; this process is called supervised learning. We aimed to develop a novel automated self-learning quantification system to identify visible areas on capsule endoscopic images. The technique was developed using 200 capsule endoscopic images retrospectively selected from each of three patients. The rate of detection of visible areas on capsule endoscopic images between a supervised learning program, using training images labeled by a physician, and our novel automated self-learning program, using unlabeled training images without intervention by a physician, was compared. The rate of detection of visible areas was equivalent for the supervised learning program and for our automatic self-learning program. The visible areas automatically identified by self-learning program correlated to the areas identified by an experienced physician. We developed a novel self-learning automated program to identify visible areas in capsule endoscopic images.

Optical characterization and polarization calibration for rigid endoscopes

Science.gov (United States)

Garcia, Missael; Gruev, Viktor

2017-02-01

Polarization measurements give orthogonal information to spectral images making them a great tool in the characterization of environmental parameters in nature. Thus, polarization imagery has proven to be remarkably useful in a vast range of biomedical applications. One such application is the early diagnosis of flat cancerous lesions in murine colorectal tumor models, where polarization data complements NIR fluorescence analysis. Advances in nanotechnology have led to compact and precise bio-inspired imaging sensors capable of accurately co-registering multidimensional spectral and polarization information. As more applications emerge for these imagers, the optics used in these instruments get very complex and can potentially compromise the original polarization state of the incident light. Here we present a complete optical and polarization characterization of three rigid endoscopes of size 1.9mm x 10cm (Karl Storz, Germany), 5mm x 30cm, and 10mm x 33cm (Olympus, Germany), used in colonoscopy for the prevention of colitis-associated cancer. Characterization results show that the telescope optics act as retarders and effectively depolarize the linear component. These incorrect readings can cause false-positives or false-negatives leading to an improper diagnosis. In this paper, we offer a polarization calibration scheme for these endoscopes based on Mueller calculus. By modeling the optical properties from training data as real-valued Mueller matrices, we are able to successfully reconstruct the initial polarization state acquired by the imaging system.

Endoscope-Assisted Transoral Fixation of Mandibular Condyle Fractures: Submandibular Versus Transoral Endoscopic Approach.

Science.gov (United States)

Hwang, Na-Hyun; Lee, Yoon-Hwan; You, Hi-Jin; Yoon, Eul-Sik; Kim, Deok-Woo

2016-07-01

In recent years, endoscope-assisted transoral approach for condylar fracture treatment has attracted much attention. However, the surgical approach is technically challenging: the procedure requires specialized instruments and the surgeons experience a steep learning curve. During the transoral endoscopic (TE) approach several instruments are positioned through a narrow oral incision making endoscope maneuvering very difficult. For this reason, the authors changed the entry port of the endoscope from transoral to submandibular area through a small stab incision. The aim of this study is to assess the advantage of using the submandibular endoscopic intraoral approach (SEI).The SEI approach requires intraoral incision for fracture reduction and fixation, and 4 mm size submandibular stab incision for endoscope and traction wires. Fifteen patients with condyle neck and subcondyle fractures were operated under the submandibular approach and 15 patients with the same diagnosis were operated under the standard TE approach.The SEI approach allowed clear visualization of the posterior margin of the ramus and condyle, and the visual axis was parallel to the condyle ramus unit. The TE approach clearly shows the anterior margin of the condyle and the sigmoid notch. The surgical time of the SEI group was 128 minutes and the TE group was 120 minutes (P >0.05). All patients in the TE endoscope group were fixated with the trocar system, but only 2 lower neck fracture patients in the SEI group required a trocar. The other 13 subcondyle fractures were fixated with an angulated screw driver (P <0.05). There were no differences in complication and surgical outcomes.The submandibular endoscopic approach has an advantage of having more space with good visualization, and facilitated the use of an angulated screw driver.

Subsurface geometry of the San Andreas fault in southern California: Results from the Salton Seismic Imaging Project (SSIP) and strong ground motion expectations

Science.gov (United States)

Fuis, Gary S.; Bauer, Klaus; Goldman, Mark R.; Ryberg, Trond; Langenheim, Victoria; Scheirer, Daniel S.; Rymer, Michael J.; Stock, Joann M.; Hole, John A.; Catchings, Rufus D.; Graves, Robert; Aagaard, Brad T.

2017-01-01

The San Andreas fault (SAF) is one of the most studied strike‐slip faults in the world; yet its subsurface geometry is still uncertain in most locations. The Salton Seismic Imaging Project (SSIP) was undertaken to image the structure surrounding the SAF and also its subsurface geometry. We present SSIP studies at two locations in the Coachella Valley of the northern Salton trough. On our line 4, a fault‐crossing profile just north of the Salton Sea, sedimentary basin depth reaches 4 km southwest of the SAF. On our line 6, a fault‐crossing profile at the north end of the Coachella Valley, sedimentary basin depth is ∼2–3  km">∼2–3  km and centered on the central, most active trace of the SAF. Subsurface geometry of the SAF and nearby faults along these two lines is determined using a new method of seismic‐reflection imaging, combined with potential‐field studies and earthquakes. Below a 6–9 km depth range, the SAF dips ∼50°–60°">∼50°–60° NE, and above this depth range it dips more steeply. Nearby faults are also imaged in the upper 10 km, many of which dip steeply and project to mapped surface fault traces. These secondary faults may join the SAF at depths below about 10 km to form a flower‐like structure. In Appendix D, we show that rupture on a northeast‐dipping SAF, using a single plane that approximates the two dips seen in our study, produces shaking that differs from shaking calculated for the Great California ShakeOut, for which the southern SAF was modeled as vertical in most places: shorter‐period (TT<1  s) shaking is increased locally by up to a factor of 2 on the hanging wall and is decreased locally by up to a factor of 2 on the footwall, compared to shaking calculated for a vertical fault.

Miniature, minimally invasive, tunable endoscope for investigation of the middle ear.

Science.gov (United States)

Pawlowski, Michal E; Shrestha, Sebina; Park, Jesung; Applegate, Brian E; Oghalai, John S; Tkaczyk, Tomasz S

2015-06-01

We demonstrate a miniature, tunable, minimally invasive endoscope for diagnosis of the auditory system. The probe is designed to sharply image anatomical details of the middle ear without the need for physically adjusting the position of the distal end of the endoscope. This is achieved through the addition of an electrowetted, tunable, electronically-controlled lens to the optical train. Morphological imaging is enabled by scanning light emanating from an optical coherence tomography system. System performance was demonstrated by imaging part of the ossicular chain and wall of the middle ear cavity of a normal mouse. During the experiment, we electronically moved the plane of best focus from the incudo-stapedial joint to the stapedial artery. Repositioning the object plane allowed us to image anatomical details of the middle ear beyond the depth of field of a static optical system. We also demonstrated for the first time to our best knowledge, that an optical system with an electrowetted, tunable lens may be successfully employed to measure sound-induced vibrations within the auditory system by measuring the vibratory amplitude of the tympanic membrane in a normal mouse in response to pure tone stimuli.

Prediction of Helicobacter pylori status by conventional endoscopy, narrow-band imaging magnifying endoscopy in stomach after endoscopic resection of gastric cancer.

Science.gov (United States)

Yagi, Kazuyoshi; Saka, Akiko; Nozawa, Yujiro; Nakamura, Atsuo

2014-04-01

To reduce the incidence of metachronous gastric carcinoma after endoscopic resection of early gastric cancer, Helicobacter pylori eradication therapy has been endorsed. It is not unusual for such patients to be H. pylori negative after eradication or for other reasons. If it were possible to predict H. pylori status using endoscopy alone, it would be very useful in clinical practice. To clarify the accuracy of endoscopic judgment of H. pylori status, we evaluated it in the stomach after endoscopic submucosal dissection (ESD) of gastric cancer. Fifty-six patients treated by ESD were enrolled. The diagnostic criteria for H. pylori status by conventional endoscopy and narrow-band imaging (NBI)-magnifying endoscopy were decided, and H. pylori status was judged by two endoscopists. Based on the H. pylori stool antigen test as a diagnostic gold standard, conventional endoscopy and NBI-magnifying endoscopy were compared for their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Interobserver agreement was assessed in terms of κ value. Interobserver agreement was moderate (0.56) for conventional endoscopy and substantial (0.77) for NBI-magnifying endoscopy. The sensitivity, specificity, PPV, and NPV were 0.79, 0.52, 0.70, and 0.63 for conventional endoscopy and 0.91, 0.83, 0.88, and 0.86 for NBI-magnifying endoscopy, respectively. Prediction of H. pylori status using NBI-magnifying endoscopy is practical, and interobserver agreement is substantial. © 2013 John Wiley & Sons Ltd.

Development and evaluation of a light-emitting diode endoscopic light source

Science.gov (United States)

Clancy, Neil T.; Li, Rui; Rogers, Kevin; Driscoll, Paul; Excel, Peter; Yandle, Ron; Hanna, George; Copner, Nigel; Elson, Daniel S.

2012-03-01

Light-emitting diode (LED) based endoscopic illumination devices have been shown to have several benefits over arclamp systems. LEDs are energy-efficient, small, durable, and inexpensive, however their use in endoscopy has been limited by the difficulty in efficiently coupling enough light into the endoscopic light cable. We have demonstrated a highly homogenised lightpipe LED light source that combines the light from four Luminus LEDs emitting in the red, green, blue and violet using innovative dichroics that maximise light throughput. The light source spectrally combines light from highly divergent incoherent sources that have a Lambertian intensity profile to provide illumination matched to the acceptance numerical aperture of a liquid light guide or fibre bundle. The LED light source was coupled to a standard laparoscope and performance parameters (power, luminance, colour temperature) compared to a xenon lamp. Although the total illuminance from the endoscope was lower, adjustment of the LEDs' relative intensities enabled contrast enhancement in biological tissue imaging. The LED light engine was also evaluated in a minimally invasive surgery (MIS) box trainer and in vivo during a porcine MIS procedure where it was used to generate 'narrowband' images. Future work using the violet LED could enable photodynamic diagnosis of bladder cancer.

Automatic WEMVA by Focusing Subsurface Offset Virtual Sources

KAUST Repository

Sun, Bingbing

2017-05-26

Macro velocity building is important for subsequent prestack depth migration and full waveform inversion. Wave equation migration velocity analysis (WEMVA) utilizes band-limited waveform to invert the velocity in an automatic manner. Normally, inversion would be implemented by focusing the subsurface offset common image gathers(SOCIGs). We re-examine it with a different perspective and propose to view the SOCIGs and the background wavefield together as subsurface offset virtual sources(SOVS). A linear system connecting the perturbation of the position of those SOVS and velocity is derived and solved subsequently using a conjugate gradient method. Both synthetic and real dataset examples verify the correctness and effectiveness of the proposed method.

Imaging subsurface damage of grinded fused silica optics by confocal fluorescence microscopy

International Nuclear Information System (INIS)

Neauport, J.; Cormont, P.; Destribats, J.; Legros, P.; Ambard, C.

2009-01-01

We report an experimental investigation of fluorescence confocal microscopy as a tool to measure subsurface damage on grinded fused silica optics. Confocal fluorescence microscopy was performed with an excitation at the wavelength of 405 nm on fixed abrasive diamond grinded fused silica samples. We detail the measured fluorescence spectrums and compare them to those of oil based coolants and grinding slurries. We evidence that oil based coolant used in diamond grinding induces a fluorescence that marks the subsurface damages and eases its observation. Such residual traces might also be involved in the laser damage process. (authors)

A Primer on Endoscopic Electronic Medical Records

OpenAIRE

Atreja, Ashish; Rizk, Maged; Gurland, Brooke

2010-01-01

Endoscopic electronic medical record systems (EEMRs) are now increasingly utilized in many endoscopy centers. Modern EEMRs not only support endoscopy report generation, but often include features such as practice management tools, image and video clip management, inventory management, e-faxes to referring physicians, and database support to measure quality and patient outcomes. There are many existing software vendors offering EEMRs, and choosing a software vendor can be time consuming and co...

Reliability in endoscopic diagnosis of portal hypertensive gastropathy

Science.gov (United States)

de Macedo, George Fred Soares; Ferreira, Fabio Gonçalves; Ribeiro, Maurício Alves; Szutan, Luiz Arnaldo; Assef, Mauricio Saab; Rossini, Lucio Giovanni Battista

2013-01-01

AIM: To analyze reliability among endoscopists in diagnosing portal hypertensive gastropathy (PHG) and to determine which criteria from the most utilized classifications are the most suitable. METHODS: From January to July 2009, in an academic quaternary referral center at Santa Casa of São Paulo Endoscopy Service, Brazil, we performed this single-center prospective study. In this period, we included 100 patients, including 50 sequential patients who had portal hypertension of various etiologies; who were previously diagnosed based on clinical, laboratory and imaging exams; and who presented with esophageal varices. In addition, our study included 50 sequential patients who had dyspeptic symptoms and were referred for upper digestive endoscopy without portal hypertension. All subjects underwent upper digestive endoscopy, and the images of the exam were digitally recorded. Five endoscopists with more than 15 years of experience answered an electronic questionnaire, which included endoscopic criteria from the 3 most commonly used Portal Hypertensive Gastropathy classifications (McCormack, NIEC and Baveno) and the presence of elevated or flat antral erosive gastritis. All five endoscopists were blinded to the patients’ clinical information, and all images of varices were deliberately excluded for the analysis. RESULTS: The three most common etiologies of portal hypertension were schistosomiasis (36%), alcoholic cirrhosis (20%) and viral cirrhosis (14%). Of the 50 patients with portal hypertension, 84% were Child A, 12% were Child B, 4% were Child C, 64% exhibited previous variceal bleeding and 66% were previously endoscopic treated. The endoscopic parameters, presence or absence of mosaic-like pattern, red point lesions and cherry-red spots were associated with high inter-observer reliability and high specificity for diagnosing Portal Hypertensive Gastropathy. Sensitivity, specificity and reliability for the diagnosis of PHG (%) were as follows: mosaic-like pattern

A subsurface add-on for standard atomic force microscopes

Energy Technology Data Exchange (ETDEWEB)

Verbiest, G. J., E-mail: Verbiest@physik.rwth-aachen.de [JARA-FIT and II. Institute of Physics, RWTH Aachen University, 52074 Aachen (Germany); Zalm, D. J. van der; Oosterkamp, T. H.; Rost, M. J., E-mail: Rost@physics.leidenuniv.nl [Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden (Netherlands)

2015-03-15

The application of ultrasound in an Atomic Force Microscope (AFM) gives access to subsurface information. However, no commercially AFM exists that is equipped with this technique. The main problems are the electronic crosstalk in the AFM setup and the insufficiently strong excitation of the cantilever at ultrasonic (MHz) frequencies. In this paper, we describe the development of an add-on that provides a solution to these problems by using a special piezo element with a lowest resonance frequency of 2.5 MHz and by separating the electronic connection for this high frequency piezo element from all other connections. In this sense, we support researches with the possibility to perform subsurface measurements with their existing AFMs and hopefully pave also the way for the development of a commercial AFM that is capable of imaging subsurface features with nanometer resolution.

Endoscopic ultrasound features of chronic pancreatitis

DEFF Research Database (Denmark)

Rana, Surinder Singh; Vilmann, Peter

2015-01-01

As endoscopic ultrasound (EUS) is the most sensitive imaging modality for diagnosing pancreatic disorders, it can demonstrate subtle alterations in the pancreatic parenchymal and ductal structure even before traditional imaging and functional testing demonstrate any abnormality. In spite...... of this fact and abundant literature, the exact role of EUS in the diagnosis of chronic pancreatitis (CP) is still not established. The EUS features to diagnose CP have evolved over a period from a pure qualitative approach to more advanced and complicated scoring systems incorporating multiple parenchymal...... to define the exact role of these criteria. The measurement of strain ratio using quantitative EUS elastography and thus allowing quantification of pancreatic fibrosis seems to be a promising new technique....

Diagnosis of Acute Appendicitis by Endoscopic Retrograde Appendicitis Therapy (ERAT): Combination of Colonoscopy and Endoscopic Retrograde Appendicography.

Science.gov (United States)

Li, Yingchao; Mi, Chen; Li, Weizhi; She, Junjun

2016-11-01

Acute appendicitis is the most common abdominal emergency, but the diagnosis of appendicitis remains a challenge. Endoscopic retrograde appendicitis therapy (ERAT) is a new and minimally invasive procedure for the diagnosis and treatment of acute appendicitis. To investigate the diagnostic value of ERAT for acute appendicitis by the combination of colonoscopy and endoscopic retrograde appendicography (ERA). Twenty-one patients with the diagnosis of suspected uncomplicated acute appendicitis who underwent ERAT between November 2014 and January 2015 were included in this study. The main outcomes, imaging findings of acute appendicitis including colonoscopic direct-vision imaging and fluoroscopic ERA imaging, were retrospectively reviewed. Secondary outcomes included mean operative time, mean hospital stay, rate of complication, rate of appendectomy during follow-up period, and other clinical data. The diagnosis of acute appendicitis was established in 20 patients by positive ERA (5 patients) or colonoscopy (1 patient) alone or both (14 patients). The main colonoscopic imaging findings included mucosal inflammation (15/20, 75 %), appendicoliths (14/20, 70 %), and maturation (5/20, 25 %). The key points of ERA for diagnosing acute appendicitis included radiographic changes of appendix (17/20, 85 %), intraluminal appendicoliths (14/20, 70 %), and perforation (1/20, 5 %). Mean operative time of ERAT was 49.7 min, and mean hospital stay was 3.3 days. No patient converted to emergency appendectomy. Perforation occurred in one patient after appendicoliths removal was not severe and did not require invasive procedures. During at least 1-year follow-up period, only one patient underwent laparoscopic appendectomy. ERAT is a valuable procedure of choice providing a precise yield of diagnostic information for patients with suspected acute appendicitis by combination of colonoscopy and ERA.

Tracking snowmelt in the subsurface: time-lapse electrical resistivity imaging on an alpine hill slope.

Science.gov (United States)

Thayer, D.; Parsekian, A.; Hyde, K.; Beverly, D.; Speckman, H. N.; Ewers, B. E.

2015-12-01

In the mountain West region the winter snowpack provides more than 70% of our annual water supply. Modeling and predicting the timing and magnitude of snowmelt-driven water yield is difficult due to the complexities of hydrologic systems that move meltwater from snow to rivers. Particular challenges are understanding the temporal and spatial domain of subsurface hydraulic processes at relevant scales, which range from points to catchments. Subsurface characterization often requires borehole instrumentation, which is expensive and extremely difficult to install in remote, rugged terrain. Advancements in non-invasive geophysical methods allow us to monitor changes in geophysical parameters over time and infer changes in hydraulic processes. In the No-Name experimental catchment in the Medicine Bow National Forest in Wyoming, we are conducting a multi-season, time-lapse electrical resistivity imaging survey on a sub-alpine hill slope. This south-facing, partially forested slope ranges from 5 degrees to 35 degrees in steepness and consists of a soil mantle covering buried glacial talus deposits of unknown depth. A permanent grid of down-slope and cross-slope electrode arrays is monitored up to four times a day. The arrays span the entire vertical distance of the slope, from an exposed bedrock ridge to a seasonal drainage below, and cover treed and non-treed areas. Geophysical measurements are augmented by temperature and moisture time-series instrumented below the surface in a contiguous 3 meter borehole. A time-series of multiple resistivity models each day from May to July shows the changing distribution of subsurface moisture during a seasonal drying sequence punctuated by isolated rain events. Spatial patterns of changing moisture indicate that soil and gravel in the top two meters drain into a saturated layer parallel to the slope which overlies less saturated material. These results suggest that water from snowmelt and rain events tends to move down-slope beneath

Endoscopic resection of subepithelial tumors.

Science.gov (United States)

Schmidt, Arthur; Bauder, Markus; Riecken, Bettina; Caca, Karel

2014-12-16

Management of subepithelial tumors (SETs) remains challenging. Endoscopic ultrasound (EUS) has improved differential diagnosis of these tumors but a definitive diagnosis on EUS findings alone can be achieved in the minority of cases. Complete endoscopic resection may provide a reasonable approach for tissue acquisition and may also be therapeutic in case of malignant lesions. Small SET restricted to the submucosa can be removed with established basic resection techniques. However, resection of SET arising from deeper layers of the gastrointestinal wall requires advanced endoscopic methods and harbours the risk of perforation. Innovative techniques such as submucosal tunneling and full thickness resection have expanded the frontiers of endoscopic therapy in the past years. This review will give an overview about endoscopic resection techniques of SET with a focus on novel methods.

The appearance of the pre-Achilles fat pad after endoscopic calcaneoplasty

NARCIS (Netherlands)

Wiegerinck, Johannes I.; Zwiers, Ruben; van Sterkenburg, Maayke N.; Maas, Mario M.; van Dijk, C. Niek

2015-01-01

To evaluate whether the imaging features of the retrocalcaneal recess normalize on a conventional radiograph after surgery for retrocalcaneal bursitis and evaluate whether it can be reused if complaints reoccur. Patients who underwent an endoscopic calcaneoplasty at least 2 years before were

The Mojave Subsurface Bio-Geochemistry Explorer (MOSBE)

Science.gov (United States)

Guerrero, J.; Beegle, L.; Abbey, W.; Bhartia, R.; Kounaves, S.; Russell, M.; Towles, D.

2012-01-01

The MOSBE Team has developed a terrestrial field campaign to explore two subsurface biological habitats under the Mojave Desert. This field campaign will not only help us understand terrestrial desert biology, but also will develop methodologies and strategies for potential future Mars missions that would seek to explore the Martian subsurface. We have proposed to the ASTEP program to integrate a suite of field demonstrated instruments with a 20 m subsurface drill as a coherent unit, the Mojave Subsurface Bio-geochemistry Explorer. The ATK Space Modular Planetary Drill System (MPDS) requires no drilling fluid, which allows aseptic sampling, can penetrate lithic ground up to 20 meters of depth, and utilizes less than 100 Watts throughout the entire depth. The drill has been developed and demonstrated in field testing to a depth of 10 meters in Arizona, December 2002. In addition to caching a continuous core throughout the drilling depth, it also generates and caches cuttings and fines that are strata-graphically correlated with the core. As a core segment is brought to the surface, it will be analyzed for texture and structure by a color microscopic imager and for relevant chemistry and mineralogy with a UV fluorescence/Raman spectrometer. Organic and soluble ionic species will be identified through two instruments -- a microcapillary electrophoresis, and an ion trap mass spectrometer that have been developed under PIDDP, ASTID and MIDP funding.

Endoscopic Ultrasound in Endocrinology: Imaging of the Adrenals and the Endocrine Pancreas.

Science.gov (United States)

Kann, Peter Herbert

2016-01-01

Endoscopic ultrasound (EUS) imaging of adrenal glands and its application to diagnostic procedures of adrenal diseases has been reported since 1998. It can be considered a relevant advantage in the field of adrenal diseases. Indeed, EUS allows the detection of adrenal lesions (even very small ones) and their characterization, the assessment of malignancy criteria, the early detection of neoplastic recurrences, the preoperative identification of morphologically healthy parts of the glands, the differentiation of extra-adrenal from adrenal tumors, and of the pathological entities associated with adrenal insufficiency, and the fine-needle aspiration biopsy (EUS-FNA) of suspicious lesions. At the same time, its clinical relevance depends on the experience of the endosonographer. Moreover, EUS is also by far the best and most sensitive imaging technique to detect and assess the follow-up of pancreatic manifestation of MEN1 disease. It furthermore enables the preoperatively localization of insulinomas and critical structures in their neighborhood, and may be relevant in planning surgical strategy. A positive EUS in a case of insulinoma furthermore confirms the endocrine diagnosis, especially considering the differential diagnosis of hypoglycemia factitia by oral antidiabetics. It can be supplemented by EUS-FNA. Again, it has to be considered that EUS may reveal false positive and false negative results, and the quality of the findings largely depends on the endosonographer's skills and experience. The most important technical details together with the advantages and limitations of EUS, and the pathognomonic characteristic of benign and malignant disorders of the adrenals and pancreas are presented here. © 2016 S. Karger AG, Basel.

A new robotic-assisted flexible endoscope with single-hand control: endoscopic submucosal dissection in the ex vivo porcine stomach.

Science.gov (United States)

Iwasa, Tsutomu; Nakadate, Ryu; Onogi, Shinya; Okamoto, Yasuharu; Arata, Jumpei; Oguri, Susumu; Ogino, Haruei; Ihara, Eikichi; Ohuchida, Kenoki; Akahoshi, Tomohiko; Ikeda, Tetsuo; Ogawa, Yoshihiro; Hashizume, Makoto

2018-04-17

Difficulties in endoscopic operations and therapeutic procedures seem to occur due to the complexity of operating the endoscope dial as well as difficulty in performing synchronized movements with both hands. We developed a prototype robotic-assisted flexible endoscope that can be controlled with a single hand in order to simplify the operation of the endoscope. The aim of this study was to confirm the operability of the robotic-assisted flexible endoscope (RAFE) by performing endoscopic submucosal dissection (ESD). Study 1: ESD was performed manually or with RAFE by an expert endoscopist in ex vivo porcine stomachs; six operations manually and six were performed with RAFE. The procedure time per unit circumferential length/area was calculated, and the results were statistically analyzed. Study 2: We evaluated how smoothly a non-endoscopist can move a RAFE compared to a manual endoscope by assessing the designated movement of the endoscope. Study 1: En bloc resection was achieved by ESD using the RAFE. The procedure time was gradually shortened with increasing experience, and the procedure time of ESD performed with the RAFE was not significantly different from that of ESD performed with a manual endoscope. Study 2: The time for the designated movement of the endoscope was significantly shorter with a RAFE than that with a manual endoscope as for a non-endoscopist. The RAFE that we developed enabled an expert endoscopist to perform the ESD procedure without any problems and allowed a non-endoscopist to control the endoscope more easily and quickly than a manual endoscope. The RAFE is expected to undergo further development.

Accuracy of endoscopic ultrasonography for diagnosing ulcerative early gastric cancers

Science.gov (United States)

Park, Jin-Seok; Kim, Hyungkil; Bang, Byongwook; Kwon, Kyesook; Shin, Youngwoon

2016-01-01

Abstract Although endoscopic ultrasonography (EUS) is the first-choice imaging modality for predicting the invasion depth of early gastric cancer (EGC), the prediction accuracy of EUS is significantly decreased when EGC is combined with ulceration. The aim of present study was to compare the accuracy of EUS and conventional endoscopy (CE) for determining the depth of EGC. In addition, the various clinic-pathologic factors affecting the diagnostic accuracy of EUS, with a particular focus on endoscopic ulcer shapes, were evaluated. We retrospectively reviewed data from 236 consecutive patients with ulcerative EGC. All patients underwent EUS for estimating tumor invasion depth, followed by either curative surgery or endoscopic treatment. The diagnostic accuracy of EUS and CE was evaluated by comparing the final histologic result of resected specimen. The correlation between accuracy of EUS and characteristics of EGC (tumor size, histology, location in stomach, tumor invasion depth, and endoscopic ulcer shapes) was analyzed. Endoscopic ulcer shapes were classified into 3 groups: definite ulcer, superficial ulcer, and ill-defined ulcer. The overall accuracy of EUS and CE for predicting the invasion depth in ulcerative EGC was 68.6% and 55.5%, respectively. Of the 236 patients, 36 patients were classified as definite ulcers, 98 were superficial ulcers, and 102 were ill-defined ulcers, In univariate analysis, EUS accuracy was associated with invasion depth (P = 0.023), tumor size (P = 0.034), and endoscopic ulcer shapes (P = 0.001). In multivariate analysis, there is a significant association between superficial ulcer in CE and EUS accuracy (odds ratio: 2.977; 95% confidence interval: 1.255–7.064; P = 0.013). The accuracy of EUS for determining tumor invasion depth in ulcerative EGC was superior to that of CE. In addition, ulcer shape was an important factor that affected EUS accuracy. PMID:27472672

Submucosal tunnel endoscopy: Peroral endoscopic myotomy and peroral endoscopic tumor resection

Science.gov (United States)

Eleftheriadis, Nikolas; Inoue, Haruhiro; Ikeda, Haruo; Onimaru, Manabu; Maselli, Roberta; Santi, Grace

2016-01-01

Peroral endoscopic myotomy (POEM) is an innovative, minimally invasive, endoscopic treatment for esophageal achalasia and other esophageal motility disorders, emerged from the natural orifice transluminal endoscopic surgery procedures, and since the first human case performed by Inoue in 2008, showed exciting results in international level, with more than 4000 cases globally up to now. POEM showed superior characteristics than the standard 100-year-old surgical or laparoscopic Heller myotomy (LHM), not only for all types of esophageal achalasia [classical (I), vigorous (II), spastic (III), Chicago Classification], but also for advanced sigmoid type achalasia (S1 and S2), failed LHM, or other esophageal motility disorders (diffuse esophageal spasm, nutcracker esophagus or Jackhammer esophagus). POEM starts with a mucosal incision, followed by submucosal tunnel creation crossing the esophagogastric junction (EGJ) and myotomy. Finally the mucosal entry is closed with endoscopic clip placement. POEM permitted relatively free choice of myotomy length and localization. Although it is technically demanding procedure, POEM can be performed safely and achieves very good control of dysphagia and chest pain. Gastroesophageal reflux is the most common troublesome side effect, and is well controllable with proton pump inhibitors. Furthermore, POEM opened the era of submucosal tunnel endoscopy, with many other applications. Based on the same principles with POEM, in combination with new technological developments, such as endoscopic suturing, peroral endoscopic tumor resection (POET), is safely and effectively applied for challenging submucosal esophageal, EGJ and gastric cardia tumors (submucosal tumors), emerged from muscularis propria. POET showed up to know promising results, however, it is restricted to specialized centers. The present article reviews the recent data of POEM and POET and discussed controversial issues that need further study and future perspectives. PMID

MEMS-based non-rotatory circumferential scanning optical probe for endoscopic optical coherence tomography

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Xu, Yingshun; Singh, Janak; Siang, Teo Hui; Ramakrishna, Kotlanka; Premchandran, C. S.; Sheng, Chen Wei; Kuan, Chuah Tong; Chen, Nanguang; Olivo, Malini C.; Sheppard, Colin J. R.

2007-07-01

In this paper, we present a non-rotatory circumferential scanning optical probe integrated with a MEMS scanner for in vivo endoscopic optical coherence tomography (OCT). OCT is an emerging optical imaging technique that allows high resolution cross-sectional imaging of tissue microstructure. To extend its usage to endoscopic applications, a miniaturized optical probe based on Microelectromechanical Systems (MEMS) fabrication techniques is currently desired. A 3D electrothermally actuated micromirror realized using micromachining single crystal silicon (SCS) process highlights its very large angular deflection, about 45 degree, with low driving voltage for safety consideration. The micromirror is integrated with a GRIN lens into a waterproof package which is compatible with requirements for minimally invasive endoscopic procedures. To implement circumferential scanning substantially for diagnosis on certain pathological conditions, such as Barret's esophagus, the micromirror is mounted on 90 degree to optical axis of GRIN lens. 4 Bimorph actuators that are connected to the mirror on one end via supporting beams and springs are selected in this micromirror design. When actuators of the micromirror are driven by 4 channels of sinusoidal waveforms with 90 degree phase differences, beam focused by a GRIN is redirected out of the endoscope by 45 degree tilting mirror plate and achieve circumferential scanning pattern. This novel driving method making full use of very large angular deflection capability of our micromirror is totally different from previously developed or developing micromotor-like rotatory MEMS device for circumferential scanning.

Therapeutic aspects of endoscopic ultrasound

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Woodward, Timothy A.

1999-06-01

Endoscopic ultrasound (EUS) is a technology that had been used primarily as a passive imaging modality. Recent advances have enabled us to move beyond the use of EUS solely as a staging tool to an interventional device. Current studies suggest that interventional applications of EUS will allow for minimally invasive assessment and therapies in a cost-effective manner. Endoscopic ultrasound with fine needle aspiration (EUS-FNA) has been demonstrated to be a technically feasible, relatively safe method of obtaining cytologic specimens. The clinical utility of EUS- FNA appears to be greatest in the diagnosis and staging of pancreatic cancer and in the nodal staging of gastrointestinal and pulmonary malignancies. In addition, EUS-FNA has demonstrated utility in the sampling pleural and ascitic fluid not generally appreciated or assessable to standard interventions. Interventional applications of EUS include EUS-guided pseudocyst drainage, EUS-guided injection of botulinum toxin in the treatment of achalasia, and EUS- guided celiac plexus neurolysis in the treatment of pancreatic cancer pain. Finally, EUS-guided fine-needle installation is being evaluated, in conjunction with recent bimolecular treatment modalities, as a delivery system in the treatment of certain gastrointestinal tumors.

Shuttle Imaging Radar - Physical controls on signal penetration and subsurface scattering in the Eastern Sahara

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Schaber, G. G.; Mccauley, J. F.; Breed, C. S.; Olhoeft, G. R.

1986-01-01

Interpretation of Shuttle Imaging Radar-A (SIR-A) images by McCauley et al. (1982) dramatically changed previous concepts of the role that fluvial processes have played over the past 10,000 to 30 million years in shaping this now extremely flat, featureless, and hyperarid landscape. In the present paper, the near-surface stratigraphy, the electrical properties of materials, and the types of radar interfaces found to be responsible for different classes of SIR-A tonal response are summarized. The dominant factors related to efficient microwave signal penetration into the sediment blanket include (1) favorable distribution of particle sizes, (2) extremely low moisture content and (3) reduced geometric scattering at the SIR-A frequency (1.3 GHz). The depth of signal penetration that results in a recorded backscatter, here called 'radar imaging depth', was documented in the field to be a maximum of 1.5 m, or 0.25 of the calculated 'skin depth', for the sediment blanket. Radar imaging depth is estimated to be between 2 and 3 m for active sand dune materials. Diverse permittivity interfaces and volume scatterers within the shallow subsurface are responsible for most of the observed backscatter not directly attributable to grazing outcrops. Calcium carbonate nodules and rhizoliths concentrated in sandy alluvium of Pleistocene age south of Safsaf oasis in south Egypt provide effective contrast in premittivity and thus act as volume scatterers that enhance SIR-A portrayal of younger inset stream channels.

Endoscopic approaches to treatment of achalasia

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Friedel, David; Modayil, Rani; Iqbal, Shahzad; Grendell, James H.

2013-01-01

Endoscopic therapy for achalasia is directed at disrupting or weakening the lower esophageal sphincter (LES). The two most commonly utilized endoscopic interventions are large balloon pneumatic dilation (PD) and botulinum toxin injection (BTI). These interventions have been extensively scrutinized and compared with each other as well as with surgical disruption (myotomy) of the LES. PD is generally more effective in improving dysphagia in achalasia than BTI, with the latter reserved for infirm older people, and PD may approach treatment results attained with myotomy. However, PD may need to be repeated. Small balloon dilation and endoscopic stent placement for achalasia have only been used in select centers. Per oral endoscopic myotomy is a newer endoscopic modality that will likely change the treatment paradigm for achalasia. It arose from the field of natural orifice transluminal endoscopic surgery and represents a scarless endoscopic approach to Heller myotomy. This is a technique that requires extensive training and preparation and thus there should be rigorous accreditation and monitoring of outcomes to ensure safety and efficacy. PMID:23503707

A Novel Augmented Reality Navigation System for Endoscopic Sinus and Skull Base Surgery: A Feasibility Study

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Li, Liang; Yang, Jian; Chu, Yakui; Wu, Wenbo; Xue, Jin; Liang, Ping; Chen, Lei

2016-01-01

Objective To verify the reliability and clinical feasibility of a self-developed navigation system based on an augmented reality technique for endoscopic sinus and skull base surgery. Materials and Methods In this study we performed a head phantom and cadaver experiment to determine the display effect and accuracy of our navigational system. We compared cadaver head-based simulated operations, the target registration error, operation time, and National Aeronautics and Space Administration Task Load Index scores of our navigation system to conventional navigation systems. Results The navigation system developed in this study has a novel display mode capable of fusing endoscopic images to three-dimensional (3-D) virtual images. In the cadaver head experiment, the target registration error was 1.28 ± 0.45 mm, which met the accepted standards of a navigation system used for nasal endoscopic surgery. Compared with conventional navigation systems, the new system was more effective in terms of operation time and the mental workload of surgeons, which is especially important for less experienced surgeons. Conclusion The self-developed augmented reality navigation system for endoscopic sinus and skull base surgery appears to have advantages that outweigh those of conventional navigation systems. We conclude that this navigational system will provide rhinologists with more intuitive and more detailed imaging information, thus reducing the judgment time and mental workload of surgeons when performing complex sinus and skull base surgeries. Ultimately, this new navigational system has potential to increase the quality of surgeries. In addition, the augmented reality navigational system could be of interest to junior doctors being trained in endoscopic techniques because it could speed up their learning. However, it should be noted that the navigation system serves as an adjunct to a surgeon’s skills and knowledge, not as a substitute. PMID:26757365

A Novel Augmented Reality Navigation System for Endoscopic Sinus and Skull Base Surgery: A Feasibility Study.

Directory of Open Access Journals (Sweden)

Liang Li

Full Text Available To verify the reliability and clinical feasibility of a self-developed navigation system based on an augmented reality technique for endoscopic sinus and skull base surgery.In this study we performed a head phantom and cadaver experiment to determine the display effect and accuracy of our navigational system. We compared cadaver head-based simulated operations, the target registration error, operation time, and National Aeronautics and Space Administration Task Load Index scores of our navigation system to conventional navigation systems.The navigation system developed in this study has a novel display mode capable of fusing endoscopic images to three-dimensional (3-D virtual images. In the cadaver head experiment, the target registration error was 1.28 ± 0.45 mm, which met the accepted standards of a navigation system used for nasal endoscopic surgery. Compared with conventional navigation systems, the new system was more effective in terms of operation time and the mental workload of surgeons, which is especially important for less experienced surgeons.The self-developed augmented reality navigation system for endoscopic sinus and skull base surgery appears to have advantages that outweigh those of conventional navigation systems. We conclude that this navigational system will provide rhinologists with more intuitive and more detailed imaging information, thus reducing the judgment time and mental workload of surgeons when performing complex sinus and skull base surgeries. Ultimately, this new navigational system has potential to increase the quality of surgeries. In addition, the augmented reality navigational system could be of interest to junior doctors being trained in endoscopic techniques because it could speed up their learning. However, it should be noted that the navigation system serves as an adjunct to a surgeon's skills and knowledge, not as a substitute.

[Endoscopic extraction of gallbladder calculi].

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Kühner, W; Frimberger, E; Ottenjann, R

1984-06-29

Endoscopic extraction of gallbladder stones were performed, as far as we know for the first time, in three patients with combined choledochocystolithiasis. Following endoscopic papillotomy (EPT) and subsequent mechanical lithotripsy of multiple choledochal concrements measuring up to 3 cm the gallbladder stones were successfully extracted with a Dormia basket through the cystic duct. The patients have remained free of complications after the endoscopic intervention.

Endoscopic findings following retroperitoneal pancreas transplantation.

Science.gov (United States)

Pinchuk, Alexey V; Dmitriev, Ilya V; Shmarina, Nonna V; Teterin, Yury S; Balkarov, Aslan G; Storozhev, Roman V; Anisimov, Yuri A; Gasanov, Ali M

2017-07-01

An evaluation of the efficacy of endoscopic methods for the diagnosis and correction of surgical and immunological complications after retroperitoneal pancreas transplantation. From October 2011 to March 2015, 27 patients underwent simultaneous retroperitoneal pancreas-kidney transplantation (SPKT). Diagnostic oesophagogastroduodenoscopy (EGD) with protocol biopsy of the donor and recipient duodenal mucosa and endoscopic retrograde pancreatography (ERP) were performed to detect possible complications. Endoscopic stenting of the main pancreatic duct with plastic stents and three-stage endoscopic hemostasis were conducted to correct the identified complications. Endoscopic methods showed high efficiency in the timely diagnosis and adequate correction of complications after retroperitoneal pancreas transplantation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Transanal endoscopic microsurgery versus endoscopic mucosal resection for large rectal adenomas (TREND-study)

NARCIS (Netherlands)

F.J.C. van den Broek (Frank); E.J.R. de Graaf (Eelco); M.G.W. Dijkgraaf (Marcel); J.B. Reitsma (Johannes); J. Haringsma (Jelle); R. Timmer (Robin); B.L. Weusten (Bas); M.F. Gerhards (Michael); E.C. Consten (Esther); M.P. Schwartz (Matthijs); M.J. Boom (Maarten); E.J. Derksen (Erik); A.B. Bijnen (Bart); P.H.P. Davids (Paul); C. Hoff (Christiaan); H.M. van Dullemen (Hendrik); G.D.N. Heine (Dimitri); K. van der Linde (Klaas); J.M. Jansen (Jeroen); R.C.H. Mallant-Hent (Rosalie); R. Breumelhof (Ronald); H. Geldof (Han); J.C. Hardwick (James); P. Doornebosch (Pascal); A.C.T.M. Depla (Annekatrien); M.F. Ernst (Miranda); I.P. van Munster (Ivo); I.H.J.T. de Hingh (Ignace); E.J. Schoon (Erik); W.A. Bemelman (Willem); P. Fockens (Paul); E. Dekker (Evelien)

2009-01-01

textabstractBackground: Recent non-randomized studies suggest that extended endoscopic mucosal resection (EMR) is equally effective in removing large rectal adenomas as transanal endoscopic microsurgery (TEM). If equally effective, EMR might be a more cost-effective approach as this strategy does

Multimodal Navigation in Endoscopic Transsphenoidal Resection of Pituitary Tumors using Image-based Vascular and Cranial Nerve Segmentation: A Prospective Validation Study

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Dolati, Parviz; Eichberg, Daniel; Golby, Alexandra; Zamani, Amir; Laws, Edward

2016-01-01

Introduction Transsphenoidal surgery (TSS) is a well-known approach for the treatment of pituitary tumors. However, lateral misdirection and vascular damage, intraoperative CSF leakage, and optic nerve and vascular injuries are all well-known complications, and the risk of adverse events is more likely in less experienced hands. This prospective study was conducted to validate the accuracy of image-based segmentation in localization of neurovascular structures during TSS. Methods Twenty-five patients with pituitary tumors underwent preoperative 3TMRI, which included thin-sectioned 3D space T2, 3D Time of Flight and MPRAGE sequences. Images were reviewed by an expert independent neuroradiologist. Imaging sequences were loaded in BrainLab iPlanNet (16/25 cases) or Stryker (9/25 cases) image guidance platforms for segmentation and pre-operative planning. After patient registration into the neuronavigation system and subsequent surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe on or as close as possible to the target. The audible pulsations of the bilateral ICA were confirmed using a micro-Doppler probe. Results Pre-operative segmentation of the ICA and cavernous sinus matched with the intra-operative endoscopic and micro-Doppler findings in all cases (Dice Similarity Coefficient =1). This information reassured the surgeons with regard to the lateral extent of bone removal at the sellar floor and the limits of lateral exploration. Excellent correspondence between image-based segmentation and the endoscopic view was also evident at the surface of the tumor and at the tumor-normal gland interfaces. This assisted in preventing unnecessary removal of the normal pituitary gland. Image-guidance assisted the surgeons in localizing the optic nerve and chiasm in 64% of the cases and the diaphragma sella in 52% of cases, which helped to determine the limits of upward exploration and to decrease the risk of CSF

Outcomes after endoscopic port surgery for spontaneous intracerebral hematomas.

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Ochalski, Pawel; Chivukula, Srinivas; Shin, Samuel; Prevedello, Daniel; Engh, Johnathan

2014-05-01

Spontaneous intracerebral hemorrhages (ICHs) cause significant morbidity and mortality. Traditional open surgical management strategies offer limited benefit except for the most superficial hemorrhages in select patients. Recent reports suggest that endoscopic approaches may improve outcomes, particularly for deep subcortical hemorrhages. However, the management of these patients remains controversial. We reviewed our experience using endoscopic port surgery to identify characteristics that may predict acceptable outcomes. We completed a retrospective chart and imaging review of patients who underwent endoscopic port surgery for evacuation of spontaneous ICH at a single center. Data were gathered regarding patient demographics, hemorrhage locations, operative findings, and clinical outcomes. From 2007 to 2011, 18 patients underwent evacuation of spontaneous intracerebral hematomas using an endoscopic port. The mean age in years was 62 years (range, 43-84 years). Six of 18 patients (33%) died before discharge, and 2 others (11%) died after at least 1 month of survival. Of 12 initial survivors, all were discharged to a rehabilitation or nursing facility. Complete hematoma evacuation was achieved in 7 of 18 patients, with the remaining 11 having a partial evacuation. The patients who died (n = 6) before discharge were statistically more likely to have a left-sided hemorrhage, partial evacuation, or older age than the survivors; death at least 1  month after evacuation was additionally associated with greater preoperative hematoma volumes. Our series demonstrates that endoscopic port surgery for acute intracerebral hematoma evacuation has the ability to achieve significant decompression of large and deep-seated hematomas. Patient age, extent of evacuation, laterality, and preoperative hematoma volume appear to influence patient outcome. Most overall outcomes remain poor. Future studies are necessary to determine if surgical evacuation is in fact superior to best

Endoscopic partial medial maxillectomy with mucosal flap for maxillary sinus mucoceles.

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Durr, Megan L; Goldberg, Andrew N

2014-01-01

To describe a technique of endoscopic medial maxillectomy with mucosal flap for postoperative maxillary sinus mucoceles and to present a case series of subjects who underwent this procedure. This case series includes four subjects with postoperative maxillary sinus mucoceles who underwent resection via endoscopic partial medial maxillectomy with a mucosal flap. We will discuss the clinical presentation, imaging characteristics, operative details, and outcomes. Four subjects are included in this study. The average age at the time of medial maxillectomy was 52 years (range 35-65 years). Three subjects (75%) were female. One subject (25%) had bilateral postoperative maxillary sinus mucoceles. Two subjects (50%) had unilateral right sided mucoceles, and the remaining subject had a unilateral left sided mucocele. All subjects had a history of multiple sinus procedures for chronic sinusitis including Caldwell-Luc procedures ipsilateral to the postoperative mucocele. All subjects underwent endoscopic medial maxillectomy without complication and were symptom free at the last follow up appointment, average 24 months (range 3-71 months) after medial maxillectomy. For postoperative maxillary sinus mucoceles in locations that are difficult to access via the middle meatus antrostomy, we recommend endoscopic medial maxillectomy with mucosal flap. Our preliminary experience with four subjects demonstrates complete resolution of symptoms after this procedure. Copyright © 2014 Elsevier Inc. All rights reserved.

Transanal endoscopic microsurgery versus endoscopic mucosal resection for large rectal adenomas (TREND-study)

NARCIS (Netherlands)

van den Broek, Frank J. C.; de Graaf, Eelco J. R.; Dijkgraaf, Marcel G. W.; Haringsma, Jelle; Timmer, Robin; Weusten, Bas L. A. M.; Gerhards, Michael F.; Consten, Esther C. J.; Schwartz, Matthijs P.; Boom, Maarten J.; Derksen, Erik J.; Bijnen, A. Bart; Davids, Paul H. P.; Hoff, Christiaan; van Dullemen, Hendrik M.; Heine, G. Dimitri N.; van der Linde, Klaas; Jansen, Jeroen M.; Mallant-Hent, Rosalie C. H.; Breumelhof, Ronald; Geldof, Han; Hardwick, James C. H.; Doornebosch, Pascal G.; Depla, Annekatrien C. T. M.; Ernst, Miranda F.; van Munster, Ivo P.; de Hingh, Ignace H. J. T.; Schoon, Erik J.; Bemelman, Willem A.; Fockens, Paul; Dekker, Evelien; Reitsma, J.

2009-01-01

Background: Recent non-randomized studies suggest that extended endoscopic mucosal resection (EMR) is equally effective in removing large rectal adenomas as transanal endoscopic microsurgery (TEM). If equally effective, EMR might be a more cost-effective approach as this strategy does not require

[Endoscopic full-thickness resection].

Science.gov (United States)

Meier, B; Schmidt, A; Caca, K

2016-08-01

Conventional endoscopic resection techniques such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are powerful tools for the treatment of gastrointestinal (GI) neoplasms. However, those techniques are limited to the superficial layers of the GI wall (mucosa and submucosa). Lesions without lifting sign (usually arising from deeper layers) or lesions in difficult anatomic positions (appendix, diverticulum) are difficult - if not impossible - to resect using conventional techniques, due to the increased risk of complications. For larger lesions (>2 cm), ESD appears to be superior to the conventional techniques because of the en bloc resection, but the procedure is technically challenging, time consuming, and associated with complications even in experienced hands. Since the development of the over-the-scope clips (OTSC), complications like bleeding or perforation can be endoscopically better managed. In recent years, different endoscopic full-thickness resection techniques came to the focus of interventional endoscopy. Since September 2014, the full-thickness resection device (FTRD) has the CE marking in Europe for full-thickness resection in the lower GI tract. Technically the device is based on the OTSC system and combines OTSC application and snare polypectomy in one step. This study shows all full-thickness resection techniques currently available, but clearly focuses on the experience with the FTRD in the lower GI tract.

Folate receptor overexpression can be visualized in real time during pituitary adenoma endoscopic transsphenoidal surgery with near-infrared imaging.

Science.gov (United States)

Lee, John Y K; Cho, Steve S; Zeh, Ryan; Pierce, John T; Martinez-Lage, Maria; Adappa, Nithin D; Palmer, James N; Newman, Jason G; Learned, Kim O; White, Caitlin; Kharlip, Julia; Snyder, Peter; Low, Philip S; Singhal, Sunil; Grady, M Sean

2017-08-25

OBJECTIVE Pituitary adenomas account for approximately 10% of intracranial tumors and have an estimated prevalence of 15%-20% in the general US population. Resection is the primary treatment for pituitary adenomas, and the transsphenoidal approach remains the most common. The greatest challenge with pituitary adenomas is that 20% of patients develop tumor recurrence. Current approaches to reduce recurrence, such as intraoperative MRI, are costly, associated with high false-positive rates, and not recommended. Pituitary adenomas are known to overexpress folate receptor alpha (FRα), and it was hypothesized that OTL38, a folate analog conjugated to a near-infrared (NIR) fluorescent dye, could provide real-time intraoperative visual contrast of the tumor versus the surrounding nonneoplastic tissues. The preliminary results of this novel clinical trial are presented. METHODS Nineteen adult patients who presented with pituitary adenoma were enrolled. Patients were infused with OTL38 2-4 hours prior to surgery. A 4-mm endoscope with both visible and NIR light capabilities was used to visualize the pituitary adenoma and its margins in real time during surgery. The signal-to-background ratio (SBR) was recorded for each tumor and surrounding tissues at various endoscope-to-sella distances. Immunohistochemical analysis was performed to assess the FRα expression levels in all specimens and classify patients as having either high or low FRα expression. RESULTS Data from 15 patients (4 with null cell adenomas, 1 clinically silent gonadotroph, 1 totally silent somatotroph, 5 with a corticotroph, 3 with somatotrophs, and 1 somatocorticotroph) were analyzed in this preliminary analysis. Four patients were excluded for technical considerations. Intraoperative NIR imaging delineated the main tumors in all 15 patients with an average SBR of 1.9 ± 0.70. The FRα expression level of the adenomas and endoscope-to-sella distance had statistically significant impacts on the fluorescent

Cholangiocarcinoma in Magnetic Resonance Cholangiopancreatography and Fascioliasis in Endoscopic Ultrasonography

Directory of Open Access Journals (Sweden)

Amir Houshang Mohammad Alizadeh

2011-10-01

Full Text Available Fascioliasis is a worldwide zoonotic infection with Fasciola hepatica and Fasciola gigantica. The zoonoses are particularly endemic in sheep-raising countries and are also endemic in Iran. Typical symptoms that may be associated with fascioliasis can be divided by phases of the disease, including the acute or liver phase, the chronic or biliary phase, and ectopic or pharyngeal fascioliasis. Cholestatic symptoms may be absent, and in some cases diagnosis and treatment may be preceded by a long period of abdominal pain, eosinophilia and vague gastrointestinal symptoms. We report a case with epigastric and upper quadrant abdominal pain for the last 4 years, with imaging suggesting cholangiocarcinoma. Considering a new concept of endoscopic ultrasonography, at last F. hepatica was extracted with endoscopic retrograde cholangiography.

Endoscopic full-thickness resection: Current status.

Science.gov (United States)

Schmidt, Arthur; Meier, Benjamin; Caca, Karel

2015-08-21

Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices.

Outcomes After Conservative, Endoscopic, and Surgical Treatment of Groove Pancreatitis: A Systematic Review.

Science.gov (United States)

Kager, Liesbeth M; Lekkerkerker, Selma J; Arvanitakis, Marianna; Delhaye, Myriam; Fockens, Paul; Boermeester, Marja A; van Hooft, Jeanin E; Besselink, Marc G

2017-09-01

Groove pancreatitis (GP) is a focal form of chronic pancreatitis affecting the paraduodenal groove area, for which consensus on diagnosis and management is lacking. We performed a systematic review of the literature to determine patient characteristics and imaging features of GP and to evaluate clinical outcomes after treatment. Eight studies were included reporting on 335 GP patients with a median age of 47 years (range, 34 to 64 y), with 90% male, 87% smokers, and 87% alcohol consumption, and 47 months (range, 15 to 122 mo) of follow-up. Most patients presented with abdominal pain (91%) and/or weight loss (78%). Imaging frequently showed cystic lesions (91%) and duodenal stenosis (60%).Final treatment was conservative (eg, pain medication) in 29% of patients. Endoscopic treatment (eg, pseudocyst drainage) was applied in 19% of patients-34% of these patients were subsequently referred for surgery. Overall, 59% of patients were treated surgically (eg, pancreatoduodenectomy). Complete symptom relief was observed in 50% of patients who were treated conservatively, 57% who underwent endoscopic treatment, and 79% who underwent surgery. GP is associated with male gender, smoking, and alcohol consumption. The vast majority of patients presents with abdominal pain and with cystic lesions on imaging. Although surgical treatment seems to be the most effective, both conservative and endoscopic treatment are successful in about half of patients. A stepwise treatment algorithm starting with the least invasive treatment options seems advisable.

Novel methods for endoscopic training.

Science.gov (United States)

Gessner, C E; Jowell, P S; Baillie, J

1995-04-01

The development of past, present, and future endoscopic training methods is described. A historical perspective of endoscopy training guidelines and devices is used to demonstrate support for the use of novel endoscopic training techniques. Computer simulation of endoscopy, interactive learning, and virtual reality applications in endoscopy and surgery are reviewed. The goals of endoscopic simulation and challenges facing investigators in this field are discussed, with an emphasis on current and future research.

State of the art in advanced endoscopic imaging for the detection and evaluation of dysplasia and early cancer of the gastrointestinal tract

Directory of Open Access Journals (Sweden)

Coda S

2014-05-01

Full Text Available Sergio Coda,1,2 Andrew V Thillainayagam1,2 1Section of Gastroenterology and Hepatology, Department of Medicine and Photonics Group, Department of Physics, Imperial College London, London, UK; 2Endoscopy Unit, Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, UK Abstract: Ideally, endoscopists should be able to detect, characterize, and confirm the nature of a lesion at the bedside, minimizing uncertainties and targeting biopsies and resections only where necessary. However, under conventional white-light inspection – at present, the sole established technique available to most of humanity – premalignant conditions and early cancers can frequently escape detection. In recent years, a range of innovative techniques have entered the endoscopic arena due to their ability to enhance the contrast of diseased tissue regions beyond what is inherently possible with standard white-light endoscopy equipment. The aim of this review is to provide an overview of the state-of-the-art advanced endoscopic imaging techniques available for clinical use that are impacting the way precancerous and neoplastic lesions of the gastrointestinal tract are currently detected and characterized at endoscopy. The basic instrumentation and the physics behind each method, followed by the most influential clinical experience, are described. High-definition endoscopy, with or without optical magnification, has contributed to higher detection rates compared with white-light endoscopy alone and has now replaced ordinary equipment in daily practice. Contrast-enhancement techniques, whether dye-based or computed, have been combined with white-light endoscopy to further improve its accuracy, but histology is still required to clarify the diagnosis. Optical microscopy techniques such as confocal laser endomicroscopy and endocytoscopy enable in vivo histology during endoscopy; however, although of invaluable assistance for tissue characterization, they have not

Subsurface Contamination Control

Energy Technology Data Exchange (ETDEWEB)

Y. Yuan

2001-12-12

There are two objectives of this report, ''Subsurface Contamination Control''. The first is to provide a technical basis for recommending limiting radioactive contamination levels (LRCL) on the external surfaces of waste packages (WP) for acceptance into the subsurface repository. The second is to provide an evaluation of the magnitude of potential releases from a defective WP and the detectability of the released contents. The technical basis for deriving LRCL has been established in ''Retrieval Equipment and Strategy for Wp on Pallet'' (CRWMS M and O 2000g, 6.3.1). This report updates the derivation by incorporating the latest design information of the subsurface repository for site recommendation. The derived LRCL on the external surface of WPs, therefore, supercede that described in CRWMS M and O 2000g. The derived LRCL represent the average concentrations of contamination on the external surfaces of each WP that must not be exceeded before the WP is to be transported to the subsurface facility for emplacement. The evaluation of potential releases is necessary to control the potential contamination of the subsurface repository and to detect prematurely failed WPs. The detection of failed WPs is required in order to provide reasonable assurance that the integrity of each WP is intact prior to MGR closure. An emplaced WP may become breached due to manufacturing defects or improper weld combined with failure to detect the defect, by corrosion, or by mechanical penetration due to accidents or rockfall conditions. The breached WP may release its gaseous and volatile radionuclide content to the subsurface environment and result in contaminating the subsurface facility. The scope of this analysis is limited to radioactive contaminants resulting from breached WPs during the preclosure period of the subsurface repository. This report: (1) documents a method for deriving LRCL on the external surfaces of WP for acceptance into the

Combined transnasal and transoral endoscopic approach to a transsphenoidal encephalocele in an infant.

Science.gov (United States)

Tan, Sien Hui; Mun, Kein Seong; Chandran, Patricia Ann; Manuel, Anura Michelle; Prepageran, Narayanan; Waran, Vicknes; Ganesan, Dharmendra

2015-07-01

This paper reports an unusual case of a transsphenoidal encephalocele and discusses our experience with a minimally invasive management. To the best of our knowledge, we present the first case of a combined endoscopic transnasal and transoral approach to a transsphenoidal encephalocele in an infant. A 17-day-old boy, who was referred for further assessment of upper airway obstruction, presented with respiratory distress and feeding difficulties. Bronchoscopy and imaging revealed a transsphenoidal encephalocele. At the age of 48 days, he underwent a combined endoscopic transnasal and transoral excision of the nasal component of the encephalocele. This approach, with the aid of neuronavigation, allows good demarcation of the extra-cranial neck of the transsphenoidal encephalocele. We were able to cauterize and carefully dissect the sac prior to excision. The defect of the neck was clearly visualized, and Valsalva manoeuvre was performed to exclude any CSF leak. As the defect was small, it was allowed to heal by secondary intention. The patient's recovery was uneventful, and he tolerated full feeds orally on day 2. Postoperative imaging demonstrated no evidence of recurrence of the nasal encephalocele. Endoscopic follow-up showed good healing of the mucosa and no cerebrospinal fluid leak. The surgical management of transsphenoidal encephalocele in neonates and infants is challenging. We describe a safe technique with low morbidity in managing such a condition. The combined endoscopic transnasal and transoral approach with neuronavigation is a minimally invasive, safe and feasible alternative, even for children below 1 year of age.

Endoscopic medial maxillectomy breaking new frontiers.

Science.gov (United States)

Mohanty, Sanjeev; Gopinath, M

2013-07-01

Endoscopy has changed the perspective of rhinologist towards the nose. It has revolutionised the surgical management of sinonasal disorders. Sinus surgeries were the first to get the benefit of endoscope. Gradually the domain of endoscopic surgery extended to the management of sino nasal tumours. Traditionally medial maxillectomy was performed through lateral rhinotomy or mid facial degloving approach. Endoscopic medial maxillectomy has been advocated by a number of authors in the management of benign sino-nasal tumours. We present our experience of endoscopic medial maxillectomy in the management of sinonasal pathologies.

Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda

Energy Technology Data Exchange (ETDEWEB)

Pyrak-Nolte, Laura J [Purdue Univ., West Lafayette, IN (United States); DePaolo, Donald J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Pietraß, Tanja [USDOE Office of Science, Washington, DC (United States)

2015-05-22

. In response, the Office of Science, through its Office of Basic Energy Science (BES), convened a roundtable consisting of 15 national lab, university and industry geoscience experts to brainstorm basic research areas that underpin the SubTER goals but are currently underrepresented in the BES research portfolio. Held in Germantown, Maryland on May 22, 2015, the round-table participants developed a basic research agenda that is detailed in this report. Highlights include the following: -A grand challenge calling for advanced imaging of stress and geological processes to help understand how stresses and chemical substances are distributed in the subsurface—knowledge that is critical to all aspects of subsurface engineering; -A priority research direction aimed at achieving control of fluid flow through fractured media; -A priority research direction aimed at better understanding how mechanical and geochemical perturbations to subsurface rock systems are coupled through fluid and mineral interactions; -A priority research direction aimed at studying the structure, permeability, reactivity and other properties of nanoporous rocks, like shale, which have become critical energy materials and exhibit important hallmarks of mesoscale materials; -A cross-cutting theme that would accelerate development of advanced computational methods to describe heterogeneous time-dependent geologic systems that could, among other potential benefits, provide new and vastly improved models of hydraulic fracturing and its environmental impacts; -A cross-cutting theme that would lead to the creation of “geo-architected materials” with controlled repeatable heterogeneity and structure that can be tested under a variety of thermal, hydraulic, chemical and mechanical conditions relevant to subsurface systems; -A cross-cutting theme calling for new laboratory studies on both natural and geo-architected subsurface materials that deploy advanced high-resolution 3D imaging and chemical analysis

Endoscopic management of bleeding peptic ulcers

International Nuclear Information System (INIS)

Farooqi, J.I.; Farooqi, R.J.

2001-01-01

Peptic ulcers account for more than half of the cases of non variceal upper gastrointestinal (GI) bleeding and therefore, are the focus of most of the methods of endoscopic hemostasis. Surgical intervention is now largely reserved for patients in whom endoscopic hemostasis has failed. A variety of endoscopic techniques have been employed to stop bleeding and reduce the risk of rebleeding, with no major differences in outcome between these methods. These include injection therapy, fibrin injection, heater probe, mono polar electrocautery, bipolar electrocautery, lasers and mechanical hemo clipping. The most important factor in determining outcome after gastrointestinal bleeding is rebleeding or persistent bleeding. The endoscopic appearance of an ulcer, however, provides the most useful prognostic information for bleeding. Recurrent bleeding after initial endoscopic hemostasis occurs in 15-20% of patients with a bleeding peptic ulcer. The best approach to these patients remains controversial; the current options are repeat endoscopic therapy with the same or a different technique, emergency surgery or semi elective surgery after repeat endoscopic hemostasis. The combination of epinephrine injection with thermal coagulation may be more effective than epinephrine injection alone. Newer modalities such as fibrin injection or the application of hemo clips appear promising and comparative studies are awaited. (author)

Clinical evaluation of endoscopic trimodal imaging for the detection and differentiation of colonic polyps.

Science.gov (United States)

van den Broek, Frank J C; Fockens, Paul; Van Eeden, Susanne; Kara, Mohammed A; Hardwick, James C H; Reitsma, Johannes B; Dekker, Evelien

2009-03-01

Endoscopic trimodal imaging (ETMI) incorporates high-resolution endoscopy (HRE) and autofluorescence imaging (AFI) for adenoma detection, and narrow-band imaging (NBI) for differentiation of adenomas from nonneoplastic polyps. The aim of this study was to compare AFI with HRE for adenoma detection and to assess the diagnostic accuracy of NBI for differentiation of polyps. This was a randomized trial of tandem colonoscopies. The study was performed at the Academic Medical Center in Amsterdam. One hundred patients underwent colonoscopy with ETMI. Each colonic segment was examined twice for polyps, once with HRE and once with AFI, in random order per patient. All detected polyps were assessed with NBI for pit pattern and with AFI for color, and subsequently removed. Histopathology served as the gold standard for diagnosis. The main outcome measures of this study were adenoma miss-rates of AFI and HRE, and diagnostic accuracy of NBI and AFI for differentiating adenomas from nonneoplastic polyps. Among 50 patients examined with AFI first, 32 adenomas were detected initially. Subsequent inspection with HRE identified 8 additional adenomas. Among 50 patients examined with HRE first, 35 adenomas were detected initially. Successive AFI yielded 14 additional adenomas. The adenoma miss-rates of AFI and HRE therefore were 20% and 29%, respectively (P = .351). The sensitivity, specificity, and overall accuracy of NBI for differentiation were 90%, 70%, and 79%, respectively; corresponding figures for AFI were 99%, 35%, and 63%, respectively. The overall adenoma miss-rate was 25%; AFI did not significantly reduce the adenoma miss-rate compared with HRE. Both NBI and AFI had a disappointing diagnostic accuracy for polyp differentiation, although AFI had a high sensitivity.

Per-oral endoscopic myotomy: Major advance in achalasia treatment and in endoscopic surgery

Science.gov (United States)

Friedel, David; Modayil, Rani; Stavropoulos, Stavros N

2014-01-01

Per-oral endoscopic myotomy (POEM) represents a natural orifice endoscopic surgery (NOTES) approach to laparoscopy Heller myotomy (LHM). POEM is arguably the most successful clinical application of NOTES. The growth of POEM from a single center in 2008 to approximately 60 centers worldwide in 2014 with several thousand procedures having been performed attests to the success of POEM. Initial efficacy, safety and acid reflux data suggest at least equivalence of POEM to LHM, the previous gold standard for achalasia therapy. Adjunctive techniques used in the West include impedance planimetry for real-time intraprocedural luminal assessment and endoscopic suturing for challenging mucosal defect closures during POEM. The impact of POEM extends beyond the realm of esophageal motility disorders as it is rapidly popularizing endoscopic submucosal dissection in the West and spawning offshoots that use the submucosal tunnel technique for a host of new indications ranging from resection of tumors to pyloromyotomy for gastroparesis. PMID:25548473

Endoscopic tissue diagnosis of cholangiocarcinoma.

LENUS (Irish Health Repository)

Harewood, Gavin C

2008-09-01

The extremely poor outcome in patients with cholangiocarcinoma, in large part, reflects the late presentation of these tumors and the challenging nature of establishing a tissue diagnosis. Establishing a diagnosis of cholangiocarcinoma requires obtaining evidence of malignancy from sampling of the epithelium of the biliary tract, which has proven to be challenging. Although endoscopic ultrasound-guided fine needle aspiration performs slightly better than endoscopic retrograde cholangiopancreatography in diagnosing cholangiocarcinoma, both endoscopic approaches demonstrate disappointing performance characteristics.

Endoscopic repair of transsellar transsphenoidal meningoencephalocele; case report and review of approaches

Directory of Open Access Journals (Sweden)

Maryam Jalessi, M.D.

2015-06-01

Full Text Available We present an extremely rare case of transsellar transsphenoidal meningoencephalocele in a 36-year-old woman with pituitary dwarfism complaining of nasal obstruction. Imaging studies showed a bony defect in the sellar floor and sphenoid sinus with huge nasopharyngeal mass and 3rd ventricle involvement. Using endoscopic endonasal approach the sac was partially removed and the defect was reconstructed with fat and fascial graft, and buttressed with titanium mesh and septal flap. Visual field improvement was noticed post-operatively and no complication was encountered during follow-up. So, endoscopic endonasal approach with partial resection of the sac is a safe and effective treatment for this disease

Papillary Ependymoma WHO Grade II of the Aqueduct Treated by Endoscopic Tumor Resection

Directory of Open Access Journals (Sweden)

Andreas M. Stark

2009-01-01

Full Text Available Papillary ependymoma is a rare tumor that may be located along the ventricular walls or within the spinal cord. We report the case of a 54-year-old patient with a papillary ependymoma WHO grade II arising at the entrance of the aqueduct. The tumor caused hydrocephalus. The tumor was completely removed via a right-sided endoscopic approach with restoration of the aqueduct. The free cerebrospinal fluid passage through the aqueduct was not only visualized by endoscopy but also controlled by intraoperative high-field magnetic resonance imaging. Therefore, an additional endoscopic third ventriculostomy was unneccessary.

TU-AB-202-12: A Novel Method to Map Endoscopic Video to CT for Treatment Planning and Toxicity Analysis in Radiation Therapy

International Nuclear Information System (INIS)

Ingram, W; Yang, J; Beadle, B; Wendt, R; Rao, A; Court, L

2016-01-01

Purpose: Endoscopic examinations are routine procedures for head-and-neck cancer patients. Our goal is to develop a method to map the recorded video to CT, providing valuable information for radiotherapy treatment planning and toxicity analysis. Methods: We map video frames to CT via virtual endoscopic images rendered at the real endoscope’s CT-space coordinates. We developed two complementary methods to find these coordinates by maximizing real-to-virtual image similarity:(1)Endoscope Tracking: moves the virtual endoscope frame-by-frame until the desired frame is reached. Utilizes prior knowledge of endoscope coordinates, but sensitive to local optima. (2)Location Search: moves the virtual endoscope along possible paths through the volume to find the desired frame. More robust, but more computationally expensive. We tested these methods on clay phantoms with embedded markers for point mapping and protruding bolus material for contour mapping, and we assessed them qualitatively on three patient exams. For mapped points we calculated 3D-distance errors, and for mapped contours we calculated mean absolute distances (MAD) from CT contours. Results: In phantoms, Endoscope Tracking had average point error=0.66±0.50cm and average bolus MAD=0.74±0.37cm for the first 80% of each video. After that the virtual endoscope got lost, increasing these values to 4.73±1.69cm and 4.06±0.30cm. Location Search had point error=0.49±0.44cm and MAD=0.53±0.28cm. Point errors were larger where the endoscope viewed the surface at shallow angles<10 degrees (1.38±0.62cm and 1.22±0.69cm for Endoscope Tracking and Location Search, respectively). In patients, Endoscope Tracking did not make it past the nasal cavity. However, Location Search found coordinates near the correct location for 70% of test frames. Its performance was best near the epiglottis and in the nasal cavity. Conclusion: Location Search is a robust and accurate technique to map endoscopic video to CT. Endoscope

Current Status of Peroral Endoscopic Myotomy

Science.gov (United States)

Cho, Young Kwan; Kim, Seong Hwan

2018-01-01

Peroral endoscopic myotomy (POEM) has been established as an optional treatment for achalasia. POEM is an endoluminal procedure that involves dissection of esophageal muscle fibers followed by submucosal tunneling. Inoue first attempted to use POEM for the treatment of achalasia in humans. Expanded indications of POEM include classic indications such as type I, type II, type III achalasia, failed prior treatments, including Botulinum toxin injection, endoscopic balloon dilation, laparoscopic Heller myotomy, and hypertensive motor disorders such as diffuse esophageal spasm, jackhammer esophagus. Contraindications include prior radiation therapy to the esophagus and prior extensive esophageal mucosal resection/ablation involving the POEM field. Most of the complications are minor and self-limited and can be managed conservatively. As POEM emerged as the main treatment for achalasia, various adaptations to tunnel endoscopic surgery have been attempted. Tunnel endoscopic surgery includes POEM, peroral endoscopic tumor resection, gastric peroral endoscopic pyloromyotomy. POEM has been widely accepted as a treatment for all types of achalasia, even for specific cases such as achalasia with failed prior treatments, and hypertensive motor disorders. PMID:29397656

Current Status of Peroral Endoscopic Myotomy.

Science.gov (United States)

Cho, Young Kwan; Kim, Seong Hwan

2018-01-01

Peroral endoscopic myotomy (POEM) has been established as an optional treatment for achalasia. POEM is an endoluminal procedure that involves dissection of esophageal muscle fibers followed by submucosal tunneling. Inoue first attempted to use POEM for the treatment of achalasia in humans. Expanded indications of POEM include classic indications such as type I, type II, type III achalasia, failed prior treatments, including Botulinum toxin injection, endoscopic balloon dilation, laparoscopic Heller myotomy, and hypertensive motor disorders such as diffuse esophageal spasm, jackhammer esophagus. Contraindications include prior radiation therapy to the esophagus and prior extensive esophageal mucosal resection/ablation involving the POEM field. Most of the complications are minor and self-limited and can be managed conservatively. As POEM emerged as the main treatment for achalasia, various adaptations to tunnel endoscopic surgery have been attempted. Tunnel endoscopic surgery includes POEM, peroral endoscopic tumor resection, gastric peroral endoscopic pyloromyotomy. POEM has been widely accepted as a treatment for all types of achalasia, even for specific cases such as achalasia with failed prior treatments, and hypertensive motor disorders.

Current Status of Peroral Endoscopic Myotomy

Directory of Open Access Journals (Sweden)

Young Kwan Cho

2018-01-01

Full Text Available Peroral endoscopic myotomy (POEM has been established as an optional treatment for achalasia. POEM is an endoluminal procedure that involves dissection of esophageal muscle fibers followed by submucosal tunneling. Inoue first attempted to use POEM for the treatment of achalasia in humans. Expanded indications of POEM include classic indications such as type I, type II, type III achalasia, failed prior treatments, including Botulinum toxin injection, endoscopic balloon dilation, laparoscopic Heller myotomy, and hypertensive motor disorders such as diffuse esophageal spasm, jackhammer esophagus. Contraindications include prior radiation therapy to the esophagus and prior extensive esophageal mucosal resection/ablation involving the POEM field. Most of the complications are minor and self-limited and can be managed conservatively. As POEM emerged as the main treatment for achalasia, various adaptations to tunnel endoscopic surgery have been attempted. Tunnel endoscopic surgery includes POEM, peroral endoscopic tumor resection, gastric peroral endoscopic pyloromyotomy. POEM has been widely accepted as a treatment for all types of achalasia, even for specific cases such as achalasia with failed prior treatments, and hypertensive motor disorders.

Endoscopic resection of cavernoma of foramen of Monro in a patient with familial multiple cavernomatosis.

Science.gov (United States)

Prat, Ricardo; Galeano, Inmaculada

2008-09-01

Intraventricular cavernomas are extremely infrequent and only 11 cases of cavernous hemangioma to occur at the foramen of Monro have been reported in the literature. This 56 years old patient was admitted with progressive and intractable headache of 10 days of evolution. He was known to suffer familial multiple cavernomatosis. Magnetic resonance imaging (MRI), revealed obstructive hydrocephalus due to a cavernoma located in the area of the left foramen of Monro. Under neuronavigation guidance, complete endoscopic resection of the cavernoma was performed and normal ventricular size achieved. The patient experienced transient recent memory loss that resolved within a month after surgery. In the literature attempted endoscopic resection is reported to be abandoned due to bleeding and ineffectiveness of piecemeal endoscopic resection. In this case, the multiplicity of the lesions made it advisable to resect the lesion endoscopically, to avoid an open procedure in a patient with multiple potentially surgical lesions. Endoscopic resection was uneventful with easy control of bleeding with irrigation, suction, and bipolar coagulation despite dense vascular appearance of the lesion. During the procedure, precise visualization of the vascular structures around the foramen of Monro allowed complete resection with satisfactory control of the instruments. To the best of the authors' knowledge, this is the first published cavernoma of foramen of Monro successfully resected using an endoscopic approach.

Design of signal reception and processing system of embedded ultrasonic endoscope

Science.gov (United States)

Li, Ming; Yu, Feng; Zhang, Ruiqiang; Li, Yan; Chen, Xiaodong; Yu, Daoyin

2009-11-01

Embedded Ultrasonic Endoscope, based on embedded microprocessor and embedded real-time operating system, sends a micro ultrasonic probe into coelom through the biopsy channel of the Electronic Endoscope to get the fault histology features of digestive organs by rotary scanning, and acquires the pictures of the alimentary canal mucosal surface. At the same time, ultrasonic signals are processed by signal reception and processing system, forming images of the full histology of the digestive organs. Signal Reception and Processing System is an important component of Embedded Ultrasonic Endoscope. However, the traditional design, using multi-level amplifiers and special digital processing circuits to implement signal reception and processing, is no longer satisfying the standards of high-performance, miniaturization and low power requirements that embedded system requires, and as a result of the high noise that multi-level amplifier brought, the extraction of small signal becomes hard. Therefore, this paper presents a method of signal reception and processing based on double variable gain amplifier and FPGA, increasing the flexibility and dynamic range of the Signal Reception and Processing System, improving system noise level, and reducing power consumption. Finally, we set up the embedded experiment system, using a transducer with the center frequency of 8MHz to scan membrane samples, and display the image of ultrasonic echo reflected by each layer of membrane, with a frame rate of 5Hz, verifying the correctness of the system.

Transoral endoscopic esophageal myotomy based on esophageal function testing in a survival porcine model.

Science.gov (United States)

Perretta, Silvana; Dallemagne, Bernard; Donatelli, Gianfranco; Diemunsch, Pierre; Marescaux, Jacques

2011-01-01

The most effective treatment of achalasia is Heller myotomy. To explore a submucosal endoscopic myotomy technique tailored on esophageal physiology testing and to compare it with the open technique. Prospective acute and survival comparative study in pigs (n = 12; 35 kg). University animal research center. Eight acute-4 open and 4 endoscopic-myotomies followed by 4 survival endoscopic procedures. Preoperative and postoperative manometry; esophagogastric junction (EGJ) distensibility before and after selective division of muscular fibers at the EGJ and after the myotomy was prolonged to a standard length by using the EndoFLIP Functional Lumen Imaging Probe (Crospon, Galway, Ireland). All procedures were successful, with no intraoperative and postoperative complications. In the survival group, the animals recovered promptly from surgery. Postoperative manometry demonstrated a 50% drop in mean lower esophageal sphincter pressure (LESp) in the endoscopic group (mean preoperative LESp, 22.2 ± 3.3 mm Hg; mean postoperative LESp, 11.34 ± 2.7 mm Hg; P open procedure group (mean preoperative LESp, 24.2 ± 3.2 mm Hg; mean postoperative LESp, 7.4 ± 4 mm Hg; P myotomy is feasible and safe. The lack of a significant difference in EGJ distensibility between the open and endoscopic procedure is very appealing. Were it to be perfected in a human population, this endoscopic approach could suggest a new strategy in the treatment of selected achalasia patients. Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

HIGH-RESOLUTION HELIOSEISMIC IMAGING OF SUBSURFACE STRUCTURES AND FLOWS OF A SOLAR ACTIVE REGION OBSERVED BY HINODE

International Nuclear Information System (INIS)

Zhao Junwei; Kosovichev, Alexander G.; Sekii, Takashi

2010-01-01

We analyze a solar active region observed by the Hinode Ca II H line using the time-distance helioseismology technique, and infer wave-speed perturbation structures and flow fields beneath the active region with a high spatial resolution. The general subsurface wave-speed structure is similar to the previous results obtained from Solar and Heliospheric Observatory/Michelson Doppler Imager observations. The general subsurface flow structure is also similar, and the downward flows beneath the sunspot and the mass circulations around the sunspot are clearly resolved. Below the sunspot, some organized divergent flow cells are observed, and these structures may indicate the existence of mesoscale convective motions. Near the light bridge inside the sunspot, hotter plasma is found beneath, and flows divergent from this area are observed. The Hinode data also allow us to investigate potential uncertainties caused by the use of phase-speed filter for short travel distances. Comparing the measurements with and without the phase-speed filtering, we find out that inside the sunspot, mean acoustic travel times are in basic agreement, but the values are underestimated by a factor of 20%-40% inside the sunspot umbra for measurements with the filtering. The initial acoustic tomography results from Hinode show a great potential of using high-resolution observations for probing the internal structure and dynamics of sunspots.

Ling classification describes endoscopic progressive process of achalasia and successful peroral endoscopy myotomy prevents endoscopic progression of achalasia.

Science.gov (United States)

Zhang, Wen-Gang; Linghu, En-Qiang; Chai, Ning-Li; Li, Hui-Kai

2017-05-14

To verify the hypothesis that the Ling classification describes the endoscopic progressive process of achalasia and determine the ability of successful peroral endoscopic myotomy (POEM) to prevent endoscopic progression of achalasia. We retrospectively reviewed the endoscopic findings, symptom duration, and manometric data in patients with achalasia. A total of 359 patients (197 women, 162 men) with a mean age of 42.1 years (range, 12-75 years) were evaluated. Symptom duration ranged from 2 to 360 mo, with a median of 36 mo. Patients were classified with Ling type I ( n = 119), IIa ( n = 106), IIb ( n = 60), IIc ( n = 60), or III ( n = 14), according to the Ling classification. Of the 359 patients, 349 underwent POEM, among whom 21 had an endoscopic follow-up for more than 2 years. Pre-treatment and post-treatment Ling classifications of these 21 patients were compared. Symptom duration increased significantly with increasing Ling classification (from I to III) ( P achalasia and may be able to serve as an endoscopic assessment criterion for achalasia. Successful POEM (Eckardt score ≤ 3) seems to have the ability to prevent endoscopic evolvement of achalasia. However, studies with larger populations are warranted to confirm our findings.

21 CFR 884.4100 - Endoscopic electrocautery and accessories.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Endoscopic electrocautery and accessories. 884... Surgical Devices § 884.4100 Endoscopic electrocautery and accessories. (a) Identification. An endoscopic electrocautery is a device used to perform female sterilization under endoscopic observation. It is designed to...

A new high-resolution electromagnetic method for subsurface imaging

Science.gov (United States)

Feng, Wanjie

For most electromagnetic (EM) geophysical systems, the contamination of primary fields on secondary fields ultimately limits the capability of the controlled-source EM methods. Null coupling techniques were proposed to solve this problem. However, the small orientation errors in the null coupling systems greatly restrict the applications of these systems. Another problem encountered by most EM systems is the surface interference and geologic noise, which sometimes make the geophysical survey impossible to carry out. In order to solve these problems, the alternating target antenna coupling (ATAC) method was introduced, which greatly removed the influence of the primary field and reduced the surface interference. But this system has limitations on the maximum transmitter moment that can be used. The differential target antenna coupling (DTAC) method was proposed to allow much larger transmitter moments and at the same time maintain the advantages of the ATAC method. In this dissertation, first, the theoretical DTAC calculations were derived mathematically using Born and Wolf's complex magnetic vector. 1D layered and 2D blocked earth models were used to demonstrate that the DTAC method has no responses for 1D and 2D structures. Analytical studies of the plate model influenced by conductive and resistive backgrounds were presented to explain the physical phenomenology behind the DTAC method, which is the magnetic fields of the subsurface targets are required to be frequency dependent. Then, the advantages of the DTAC method, e.g., high-resolution, reducing the geologic noise and insensitive to surface interference, were analyzed using surface and subsurface numerical examples in the EMGIMA software. Next, the theoretical advantages, such as high resolution and insensitive to surface interference, were verified by designing and developing a low-power (moment of 50 Am 2) vertical-array DTAC system and testing it on controlled targets and scaled target coils. At last, a

Buried object detection in GPR images

Science.gov (United States)

Paglieroni, David W; Chambers, David H; Bond, Steven W; Beer, W. Reginald

2014-04-29

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Single-Blinded Prospective Implementation of a Preoperative Imaging Checklist for Endoscopic Sinus Surgery.

Science.gov (United States)

Error, Marc; Ashby, Shaelene; Orlandi, Richard R; Alt, Jeremiah A

2018-01-01

Objective To determine if the introduction of a systematic preoperative sinus computed tomography (CT) checklist improves identification of critical anatomic variations in sinus anatomy among patients undergoing endoscopic sinus surgery. Study Design Single-blinded prospective cohort study. Setting Tertiary care hospital. Subjects and Methods Otolaryngology residents were asked to identify critical surgical sinus anatomy on preoperative CT scans before and after introduction of a systematic approach to reviewing sinus CT scans. The percentage of correctly identified structures was documented and compared with a 2-sample t test. Results A total of 57 scans were reviewed: 28 preimplementation and 29 postimplementation. Implementation of the sinus CT checklist improved identification of critical sinus anatomy from 24% to 84% correct ( P identification of sinus anatomic variants, including those not directly included in the systematic review implemented. Conclusion The implementation of a preoperative endoscopic sinus surgery radiographic checklist improves identification of critical anatomic sinus variations in a training population.

Endoscopic management of hilar biliary strictures

Science.gov (United States)

Singh, Rajiv Ranjan; Singh, Virendra

2015-01-01

Hilar biliary strictures are caused by various benign and malignant conditions. It is difficult to differentiate benign and malignant strictures. Postcholecystectomy benign biliary strictures are frequently encountered. Endoscopic management of these strictures is challenging. An endoscopic method has been advocated that involves placement of increasing number of stents at regular intervals to resolve the stricture. Malignant hilar strictures are mostly unresectable at the time of diagnosis and only palliation is possible.Endoscopic palliation is preferred over surgery or radiological intervention. Magnetic resonance cholangiopancreaticography is quite important in the management of these strictures. Metal stents are superior to plastic stents. The opinion is divided over the issue of unilateral or bilateral stenting.Minimal contrast or no contrast technique has been advocated during endoscopic retrograde cholangiopancreatography of these patients. The role of intraluminal brachytherapy, intraductal ablation devices, photodynamic therapy, and endoscopic ultrasound still remains to be defined. PMID:26191345

Subsurface Ventilation System Description Document

Energy Technology Data Exchange (ETDEWEB)

Eric Loros

2001-07-25

The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

Subsurface Ventilation System Description Document

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-10-12

The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

Subsurface Facility System Description Document

International Nuclear Information System (INIS)

Eric Loros

2001-01-01

The Subsurface Facility System encompasses the location, arrangement, size, and spacing of the underground openings. This subsurface system includes accesses, alcoves, and drifts. This system provides access to the underground, provides for the emplacement of waste packages, provides openings to allow safe and secure work conditions, and interfaces with the natural barrier. This system includes what is now the Exploratory Studies Facility. The Subsurface Facility System physical location and general arrangement help support the long-term waste isolation objectives of the repository. The Subsurface Facility System locates the repository openings away from main traces of major faults, away from exposure to erosion, above the probable maximum flood elevation, and above the water table. The general arrangement, size, and spacing of the emplacement drifts support disposal of the entire inventory of waste packages based on the emplacement strategy. The Subsurface Facility System provides access ramps to safely facilitate development and emplacement operations. The Subsurface Facility System supports the development and emplacement operations by providing subsurface space for such systems as ventilation, utilities, safety, monitoring, and transportation

Subsurface multidisciplinary research results at ICTJA-CSIC downhole lab and test site

Science.gov (United States)

Jurado, Maria Jose; Crespo, Jose; Salvany, Josep Maria; Teixidó, Teresa

2017-04-01

Two scientific boreholes, Almera-1 and Almera-2 were drilled in the Barcelona University campus area in 2011. The main purpose for this drilling was to create a new geophysical logging and downhole monitoring research facility and infrastructure. We present results obtained in the frame of multidisciplinary studies and experiments carried out since 2011 at the ICTJA "Borehole Geophysical Logging Lab - Scientific Boreholes Almera" downhole lab facilities. First results obtained from the scientific drilling, coring and logging allowed us to characterize the urban subsurface geology and hydrology adjacent to the Institute of Earth Sciences Jaume Almera (ICTJA-CSIC) in Barcelona. The subsurface geology and structural picture has been completed with recent geophysical studies and monitoring results. The upper section of Almera-1 214m deep hole was cased with PVC after drilling and after the logging operations. An open hole interval was left from 112m to TD (Paleozoic section). Almera-2 drilling reached 46m and was cased also with PVC to 44m. Since completion of the drilling in 2011, both Almera-1 and Almera-2 have been extensively used for research purposes, tests, training, hydrological and geophysical monitoring. A complete set of geophysical logging measurements and borehole oriented images were acquired in open hole mode of the entire Almera-1 section. Open hole measurements included acoustic and optical imaging, spectral natural gamma ray, full wave acoustic logging, magnetic susceptibility, hydrochemical-temperature logs and fluid sampling. Through casing (PVC casing) measurements included spectral gamma ray logging, full wave sonic and acoustic televiewer. A Quaternary to Paleozoic section was characterized based on the geophysical logging and borehole images interpretation and also on the complete set of (wireline) cores of the entire section. Sample availability was intended for geological macro and micro-facies detailed characterization, mineralogical and

Imaging in the Evaluation of Endoscopic or Surgical Treatment for Achalasia

OpenAIRE

Diego Palladino; Andrea Mardighian; Marilina D’Amora; Luca Roberto; Francesco Lassandro; Claudia Rossi; Gianluca Gatta; Mariano Scaglione; Guglielmi Giuseppe

2016-01-01

Purpose. Aim of the study is to evaluate the efficacy of the endoscopic (pneumatic dilation) versus surgical (Heller myotomy) treatment in patients affected by esophageal achalasia using barium X-ray examination of the digestive tract performed before and after the treatment. Materials and Methods. 19 patients (10 males and 9 females) were enrolled in this study; each patient underwent a barium X-ray examination to evaluate the esophageal diameter and the height of the barium column before a...

Endoscopic transmission of Helicobacter pylori

NARCIS (Netherlands)

Tytgat, G. N.

1995-01-01

The contamination of endoscopes and biopsy forceps with Helicobacter pylori occurs readily after endoscopic examination of H. pylori-positive patients. Unequivocal proof of iatrogenic transmission of the organism has been provided. Estimates for transmission frequency approximate to 4 per 1000

Intelligent SUBsurface Quality : Intelligent use of subsurface infrastructure for surface quality

NARCIS (Netherlands)

Hooimeijer, F.L.; Kuzniecow Bacchin, T.; Lafleur, F.; van de Ven, F.H.M.; Clemens, F.H.L.R.; Broere, W.; Laumann, S.J.; Klaassen, R.G.; Marinetti, C.

2016-01-01

This project focuses on the urban renewal of (delta) metropolises and concentrates on the question how to design resilient, durable (subsurface) infrastructure in urban renewal projects using parameters of the natural system – linking in an efficient way (a) water cycle, (b) soil and subsurface

Use of remote sensing for identification and description of subsurface drainage system condition

Czech Academy of Sciences Publication Activity Database

Tlapáková, L.; Žaloudík, Jiří; Kulhavý, Z.; Pelíšek, I.

2015-01-01

Roč. 63, č. 5 (2015), s. 1587-1599 ISSN 1211-8516 Institutional support: RVO:60077344 Keywords : subsurface drainage * remote sensing * aerial image interpretation * RPAS Subject RIV: DA - Hydrology ; Limnology

Deep subsurface microbial processes

Science.gov (United States)

Lovley, D.R.; Chapelle, F.H.

1995-01-01

Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences 1 the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of

Storage, access, and retrieval of endoscopic and laparoscopic video

Science.gov (United States)

Bellaire, Gunter; Steines, Daniel; Graschew, Georgi; Thiel, Andreas; Bernarding, Johannes; Tolxdorff, Thomas; Schlag, Peter M.

1999-05-01

The system presented here enhances documentation and data- secured, second-opinion facilities by integrating video into DICOM3.0. Digital stereoscopic video sequences (DSVS) are especially in demand for surgery (laparoscopy, microsurgery, surgical microscopy, second opinion, virtual reality). Therefore DSVS are also integrated into the DICOM video concept. We present an implementation for a medical video server extended by a DICOM interface. Security mechanisms conforming with DICOM are integrated to enable secure internet access. Digital (stereoscopic) video sequences relevant for surgery should be examined regarding the clip length necessary for diagnosis and documentation and the clip size manageable with today's hardware. Methods for DSVS compression are described, implemented, and tested. Image sources relevant for this paper include, among others, a stereoscopic laparoscope and a monoscopic endoscope. Additionally, an approach is presented to analyze the motion of the endoscopic camera for future automatic video- cutting.

Imaging near-subsurface subrosion structures and faults using SH-wave reflection seismics

Science.gov (United States)

Wadas, Sonja; Polom, Ulrich; Buness, Hermann; Krawczyk, Charlotte

2016-04-01

Subrosion is a term for underground leaching of soluble rocks and is a global phenomenon. It involves dissolution of evaporites due to the presence of unsaturated water, fractures and faults. Fractures and faults are pathways for water to circulate and to generate subsurface cavities. Depending on the leached material and the parameters of the generation process, especially the dissolution rate, different kinds of subrosion structures evolve in the subsurface. The two end members are collapse and depression structures. Subrosion is a natural process, but it can be enhanced by anthropogenic factors like manipulation of the aquifer system and groundwater flow and by e.g. extraction of saline water. The formation of sinkholes and depressions are a dangerous geohazard, especially if they occur in urban areas, which often leads to building and infrastructural damage and life-threatening situations. For this reason investigations of the processes that induce subrosion and a detailed analysis of the resulting structures are of importance. To develop a comprehensive model of near-subsurface subrosion structures, reflection seismics is one of the methods used by the Leibniz Institute for Applied Geophysics. The study area is located in the city of Bad Frankenhausen in northern Thuringia, Germany. Most of the geological underground of Thuringia is characterized by Permian deposits. Bad Frankenhausen is situated directly south of the Kyffhäuser mountain range at the Kyffhäuser Southern Margin Fault. This major fault is one of the main pathways for the circulating ground- and meteoric waters that leach the Permian deposits, especially the Leine-, Staßfurt- and Werra Formations. 2014 and 2015 eight shear wave reflection seismic profiles were carried out in the urban area of Bad Frankenhausen and three profiles in the countrified surroundings. Altogether ca. 3.6 km were surveyed using a landstreamer as receiver and an electro-dynamic vibrator as source. The surveys were

The role of multi-detector-row computed tomograph in the diagnosis of intraductal papillary-mucinous tumors of the pancreas in comparison to endoscopic retrograde pancreatography, endoscopic ultrasonography, magnetic resonance cholangiopancreatography

International Nuclear Information System (INIS)

Arikawa, Shunji; Uchida, Masafumi; Shinagawa, Masaharu

2007-01-01

Thirty patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas underwent multidetector-row CT (MD-CT) in addition to endoscopic retrograde pancreatography (ERP), and, in 27 cases magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography (EUS). The usefulness of MD-CT was investigated by comparing various imaging methods of the communication from the main pancreatic duct (MPD) to patulous/bulging papilla in addition to the indices for benign or malignant disease, the degree of dilation of the MPD, localization and size of cystic lesions, and presence or absence of neoplastic lesions, such as thickened walls and septa, intramural nodule, solid mass. With MD-CT, dilation of the MPD and localization and size of cystic lesions were accurately assessed, even in patients with obstruction of the main pancreatic duct in whom ERP was difficult to perform regardless of the presence or absence of massive amount of mucus. MD-CT with reconstructive imaging, such as multiplanar reformation (MPR) imaging and curred planar reformation (CPR) imaging, allowed us to assess communication with the MPD and patulous/bulging papilla easier than MRCP. In our study, MD-CT was useful in the evaluation of thickened walls and septa that are predictive factors of malignancy in IPMT. (author)

Gynaecological Endoscopic Surgical Education and Assessment. A diploma programme in gynaecological endoscopic surgery.

Science.gov (United States)

Campo, Rudi; Wattiez, Arnaud; Tanos, Vasilis; Di Spiezio Sardo, Attilio; Grimbizis, Grigoris; Wallwiener, Diethelm; Brucker, Sara; Puga, Marco; Molinas, Roger; O'Donovan, Peter; Deprest, Jan; Van Belle, Yves; Lissens, Ann; Herrmann, Anja; Tahir, Mahmood; Benedetto, Chiara; Siebert, Igno; Rabischong, Benoit; De Wilde, Rudy Leon

2016-04-01

In recent years, training and education in endoscopic surgery has been critically reviewed. Clinicians, both surgeons as gynaecologist who perform endoscopic surgery without proper training of the specific psychomotor skills are at higher risk to increased patient morbidity and mortality. Although the apprentice-tutor model has long been a successful approach for training of surgeons, recently, clinicians have recognised that endoscopic surgery requires an important training phase outside the operating theatre. The Gynaecological Endoscopic Surgical Education and Assessment programme (GESEA), recognises the necessity of this structured approach and implements two separated stages in its learning strategy. In the first stage, a skill certificate on theoretical knowledge and specific practical psychomotor skills is acquired through a high stake exam; in the second stage, a clinical programme is completed to achieve surgical competence and receive the corresponding diploma. Three diplomas can be awarded: (a) the Bachelor in Endoscopy; (b) the Minimally Invasive Gynaecological Surgeon (MIGS); and (c) the Master level. The Master level is sub-divided into two separate diplomas: the Master in Laparoscopic Pelvic Surgery and the Master in Hysteroscopy. The complexity of modern surgery has increased the demands and challenges to surgical education and the quality control. This programme is based on the best available scientific evidence and it counteracts the problem of the traditional surgical apprentice tutor model. It is seen as a major step toward standardization of endoscopic surgical training in general. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Pre-operative assessment of patients undergoing endoscopic, transnasal, transsphenoidal pituitary surgery.

Science.gov (United States)

Lubbe, D; Semple, P

2008-06-01

To demonstrate the importance of pre-operative ear, nose and throat assessment in patients undergoing endoscopic, transsphenoidal surgery for pituitary tumours. Literature pertaining to the pre-operative otorhinolaryngological assessment and management of patients undergoing endoscopic anterior skull base surgery is sparse. We describe two cases from our series of 59 patients undergoing endoscopic pituitary surgery. The first case involved a young male patient with a large pituitary macroadenoma. His main complaint was visual impairment. He had no previous history of sinonasal pathology and did not complain of any nasal symptoms during the pre-operative neurosurgical assessment. At the time of surgery, a purulent nasal discharge was seen emanating from both middle meati. Surgery was abandoned due to the risk of post-operative meningitis, and postponed until the patient's chronic rhinosinusitis was optimally managed. The second patient was a 47-year-old woman with a large pituitary macroadenoma, who presented to the neurosurgical department with a main complaint of diplopia. She too gave no history of previous nasal problems, and she underwent uneventful surgery using the endoscopic, transnasal approach. Two weeks after surgery, she presented to the emergency unit with severe epistaxis. A previous diagnosis of hereditary haemorrhagic telangiectasia was discovered, and further surgical and medical intervention was required before the epistaxis was finally controlled. Pre-operative otorhinolaryngological assessment is essential prior to endoscopic pituitary or anterior skull base surgery. A thorough otorhinolaryngological history will determine whether any co-morbid diseases exist which could affect the surgical field. Nasal anatomy can be assessed via nasal endoscopy and sinusitis excluded. Computed tomography imaging is a valuable aid to decisions regarding additional procedures needed to optimise access to the pituitary fossa.

Laser Imaging Facilitates Early Detection of Synchronous Adenocarcinomas in Patients with Barrett’s Esophagus

Directory of Open Access Journals (Sweden)

Chihiro Iwashita

2017-01-01

Full Text Available Barrett’s adenocarcinoma may occur in multiple sites, and recurrence and metachronous lesions are the major problems with endoscopic resection. Therefore, early detection of such lesions is ideal to achieve complete resection and obtain improved survival rates with minimally invasive treatment. Laser imaging systems allow multiple modalities of endoscopic imaging by using white light laser, flexible spectral imaging color enhancement (FICE, blue laser imaging (BLI, and linked color imaging even at a distant view. However, the usefulness of these modalities has not been sufficiently reported regarding Barrett’s adenocarcinoma. Here, we report on a patient with three synchronous lesions followed by one metachronous lesion in a long segment with changes of Barrett’s esophagus, all diagnosed with this new laser endoscopic imaging system and enhanced by using FICE and/or BLI with high contrast compared with the surrounding mucosa. Laser endoscopic imaging may facilitate the detection of malignancies in patients with early Barrett’s adenocarcinoma.

Surgical outcome of tuberculous meningitis hydrocephalus treated by endoscopic third ventriculostomy: prognostic factors and postoperative neuroimaging for functional assessment of ventriculostomy.

Science.gov (United States)

Chugh, Ashish; Husain, Mazhar; Gupta, Rakesh K; Ojha, Bal K; Chandra, Anil; Rastogi, Manu

2009-05-01

Endoscopic third ventriculostomy (ETV) is increasingly being used as an alternative treatment for post-tuberculous meningitis (TBM) hydrocephalus. The aim of this study was to affirm the role of ETV in patients with TBM hydrocephalus and also to study the usefulness of cine phase-contrast MR imaging (cine MR imaging) for functional assessment of the ETV stoma. An additional goal was to identify factors that influence the outcome of ETV, so as to define patients with TBM hydrocephalus in whom ETV is warranted. Twenty-six patients with TBM hydrocephalus treated with ETV were evaluated clinically and with cine MR imaging postoperatively. The duration of follow-up ranged from 1 to 15 months. The authors evaluated flow void changes in the floor of the third ventricle and analyzed parameters from the preoperative data, which they then used as a basis for comparison between endoscopically successful and endoscopically unsuccessful cases. The overall success rate of ETV in TBM hydrocephalus was 73.1% in this case series. Cine MR imaging showed a sensitivity of 94.73% and specificity of 71.42% for the functional assessment of third ventriculostomy in these patients, with the efficacy being maintained during follow-up. The outcome of ETV showed a statistically significant correlation with the stage of illness and presence of intraoperative cisternal exudates. Although duration of symptoms and duration of preoperative antituberculous therapy (ATT) appeared to influence the outcome, their correlation with outcome was not statistically significant. Endoscopic third ventriculostomy should be considered as the first surgical option for CSF diversion (that is, before shunt surgery) in patients with TBM hydrocephalus. Cine MR imaging is a highly effective noninvasive tool for the postoperative functional assessment of stomata. Patients who presented with a history of longer duration and those who were administered preoperative ATT for a longer period had a better outcome of

Anisotropic depth migration: reducing lateral-position uncertainty of subsurface structures in the Alberta foothills

Energy Technology Data Exchange (ETDEWEB)

Vestrum, R.W.; Lawton, D.C.

1999-01-01

Seismic velocity anisotropy causes lateral-positioning errors on seismic images, and the use of anisotropic depth migration corrects this lateral mispositioning of subsurface targets. The assumption of isotropic seismic velocities implies that traditional depth migration corrects only for positioning errors caused by lateral velocity heterogeneity, and mispositioning due to seismic anisotropy remained uncorrected on depth-migrated sections. Also, isotropic depth migration was only applied in cases in which significant lateral velocity changes occurred, and lateral mispositioning due to seismic anisotropy remained uncorrected on time-migrated sections. If seismic is to accurately image the subsurface, then there is a need for reconsidering the assumptions made in depth imaging as well as a need to reconsider at what point depth migration applies to seismic data. Now that it is possible to correct for seismic anisotropy as well as lateral velocity heterogeneity, anisotropic depth migration potentially can be used to improve seismic imaging and positioning in areas in which traditional depth migration did not apply. 5 refs.

Anisotropic depth migration: reducing lateral-position uncertainty of subsurface structures in the Alberta foothills

Energy Technology Data Exchange (ETDEWEB)

Vestrum, R.W.; Lawton, D.C.

1999-11-01

Seismic velocity anisotropy causes lateral-positioning errors on seismic images, and the use of anisotropic depth migration corrects this lateral mispositioning of subsurface targets. The assumption of isotropic seismic velocities implies that traditional depth migration corrects only for positioning errors caused by lateral velocity heterogeneity, and mispositioning due to seismic anisotropy remained uncorrected on depth-migrated sections. Also, isotropic depth migration was only applied in cases in which significant lateral velocity changes occurred, and lateral mispositioning due to seismic anisotropy remained uncorrected on time-migrated sections. If seismic is to accurately image the subsurface, then there is a need for reconsidering the assumptions made in depth imaging as well as a need to reconsider at what point depth migration applies to seismic data. Now that it is possible to correct for seismic anisotropy as well as lateral velocity heterogeneity, anisotropic depth migration potentially can be used to improve seismic imaging and positioning in areas in which traditional depth migration did not apply. 5 refs.

Endoscopic Medial Maxillectomy Breaking New Frontiers

OpenAIRE

Mohanty, Sanjeev; Gopinath, M.

2011-01-01

Endoscopy has changed the perspective of rhinologist towards the nose. It has revolutionised the surgical management of sinonasal disorders. Sinus surgeries were the first to get the benefit of endoscope. Gradually the domain of endoscopic surgery extended to the management of sino nasal tumours. Traditionally medial maxillectomy was performed through lateral rhinotomy or mid facial degloving approach. Endoscopic medial maxillectomy has been advocated by a number of authors in the management ...

Modification of endoscopic medial maxillectomy: a novel approach for inverted papilloma of the maxillary sinus.

Science.gov (United States)

Ghosh, A; Pal, S; Srivastava, A; Saha, S

2015-02-01

To describe modification to endoscopic medial maxillectomy for treating extensive Krouse stage II or III inverted papilloma of the nasal and maxillary sinus. Ten patients with inverted papilloma arising from the nasoantral area underwent diagnostic nasal endoscopy, contrast-enhanced computed tomography scanning of the paranasal sinus and pre-operative biopsy of the nasal mass. They were all managed using endoscopic medial maxillectomy and followed up for seven months to three years without recurrence. Most patients were aged 41-60 years at presentation, and most were male. Presenting symptoms were nasal obstruction, mass in the nasal cavity and epistaxis. In each case, computed tomography imaging showed a mass involving the nasal cavity and maxillary sinus, with bony remodelling. The endoscopic medial maxillectomy approach was modified by making an incision in the pyriform aperture and removing part of the anterolateral wall of the maxilla bone en bloc. Modified endoscopic medial maxillectomy providing full access to the maxillary and ethmoid sinuses is described in detail. This effective, reproducible technique is associated with reduced operative time and morbidity.

Development of preoperative planning software for transforaminal endoscopic surgery and the guidance for clinical applications.

Science.gov (United States)

Chen, Xiaojun; Cheng, Jun; Gu, Xin; Sun, Yi; Politis, Constantinus

2016-04-01

Preoperative planning is of great importance for transforaminal endoscopic techniques applied in percutaneous endoscopic lumbar discectomy. In this study, a modular preoperative planning software for transforaminal endoscopic surgery was developed and demonstrated. The path searching method is based on collision detection, and the oriented bounding box was constructed for the anatomical models. Then, image reformatting algorithms were developed for multiplanar reconstruction which provides detailed anatomical information surrounding the virtual planned path. Finally, multithread technique was implemented to realize the steady-state condition of the software. A preoperative planning software for transforaminal endoscopic surgery (TE-Guider) was developed; seven cases of patients with symptomatic lumbar disc herniations were planned preoperatively using TE-Guider. The distances to the midlines and the direction of the optimal paths were exported, and each result was in line with the empirical value. TE-Guider provides an efficient and cost-effective way to search the ideal path and entry point for the puncture. However, more clinical cases will be conducted to demonstrate its feasibility and reliability.

Site Recommendation Subsurface Layout

International Nuclear Information System (INIS)

C.L. Linden

2000-01-01

The purpose of this analysis is to develop a Subsurface Facility layout that is capable of accommodating the statutory capacity of 70,000 metric tons of uranium (MTU), as well as an option to expand the inventory capacity, if authorized, to 97,000 MTU. The layout configuration also requires a degree of flexibility to accommodate potential changes in site conditions or program requirements. The objective of this analysis is to provide a conceptual design of the Subsurface Facility sufficient to support the development of the Subsurface Facility System Description Document (CRWMS M andO 2000e) and the ''Emplacement Drift System Description Document'' (CRWMS M andO 2000i). As well, this analysis provides input to the Site Recommendation Consideration Report. The scope of this analysis includes: (1) Evaluation of the existing facilities and their integration into the Subsurface Facility design. (2) Identification and incorporation of factors influencing Subsurface Facility design, such as geological constraints, thermal loading, constructibility, subsurface ventilation, drainage control, radiological considerations, and the Test and Evaluation Facilities. (3) Development of a layout showing an available area in the primary area sufficient to support both the waste inventories and individual layouts showing the emplacement area required for 70,000 MTU and, if authorized, 97,000 MTU

Endoscopic management of intraoperative small bowel laceration during natural orifice translumenal endoscopic surgery: a blinded porcine study.

Science.gov (United States)

Fyock, Christopher J; Forsmark, Chris E; Wagh, Mihir S

2011-01-01

Natural orifice translumenal endoscopic surgery (NOTES) has recently gained great enthusiasm, but there is concern regarding the ability to endoscopically manage complications purely via natural orifices. To assess the feasibility of endoscopically managing enteral perforation during NOTES using currently available endoscopic accessories. Twelve pigs underwent transgastric or transcolonic endoscopic exploration. Full-thickness enterotomies were intentionally created to mimic accidental small bowel lacerations during NOTES. These lacerations were then closed with endoclips. In the blinded arm of the study, small bowel repair was performed by a second blinded endoscopist. Adequate closure of the laceration was confirmed with a leak test. Primary access sites were closed with endoclips or T-anchors. At necropsy, the peritoneal cavity was inspected for abscesses, bleeding, or damage to surrounding structures. The enterotomy site was examined for adequacy of closure, adhesions, or evidence of infection. Fifteen small bowel lacerations were performed in 12 animals. Successful closure was achieved in all 10 cases in the nonblinded arm. Survival animals had an uncomplicated postoperative course and all enterotomy sites were well healed without evidence of necrosis, adhesions, abscess, or bleeding at necropsy. Leak test was negative in all animals. In the blinded arm, both small intestinal lacerations could not be identified by the blinded endoscopist. Necropsy revealed open small bowel lacerations. Small intestinal injuries are difficult to localize with currently available flexible endoscopes and accessories. Endoscopic clips, however, may be adequate for closure of small bowel lacerations if the site of injury is known.

Linearized inversion frameworks toward high-resolution seismic imaging

KAUST Repository

Aldawood, Ali

2016-09-01

Seismic exploration utilizes controlled sources, which emit seismic waves that propagate through the earth subsurface and get reflected off subsurface interfaces and scatterers. The reflected and scattered waves are recorded by recording stations installed along the earth surface or down boreholes. Seismic imaging is a powerful tool to map these reflected and scattered energy back to their subsurface scattering or reflection points. Seismic imaging is conventionally based on the single-scattering assumption, where only energy that bounces once off a subsurface scatterer and recorded by a receiver is projected back to its subsurface position. The internally multiply scattered seismic energy is considered as unwanted noise and is usually suppressed or removed from the recorded data. Conventional seismic imaging techniques yield subsurface images that suffer from low spatial resolution, migration artifacts, and acquisition fingerprint due to the limited acquisition aperture, number of sources and receivers, and bandwidth of the source wavelet. Hydrocarbon traps are becoming more challenging and considerable reserves are trapped in stratigraphic and pinch-out traps, which require highly resolved seismic images to delineate them. This thesis focuses on developing and implementing new advanced cost-effective seismic imaging techniques aiming at enhancing the resolution of the migrated images by exploiting the sparseness of the subsurface reflectivity distribution and utilizing the multiples that are usually neglected when imaging seismic data. I first formulate the seismic imaging problem as a Basis pursuit denoise problem, which I solve using an L1-minimization algorithm to obtain the sparsest migrated image corresponding to the recorded data. Imaging multiples may illuminate subsurface zones, which are not easily illuminated by conventional seismic imaging using primary reflections only. I then develop an L2-norm (i.e. least-squares) inversion technique to image

Endoscopic resection of acetabular screw tip to decompress sciatic nerve following total hip arthroplasty.

Science.gov (United States)

Yoon, Sun-Jung; Park, Myung-Sik; Matsuda, Dean K; Choi, Yun Ho

2018-06-04

Sciatic nerve injuries following total hip arthroplasty are disabling complications. Although degrees of injury are variable from neuropraxia to neurotmesis, mechanical irritation of sciatic nerve might be occurred by protruding hardware. This case shows endoscopic decompression for protruded acetabular screw irritating sciatic nerve, the techniques described herein may permit broader arthroscopic/endoscopic applications for management of complications after reconstructive hip surgery. An 80-year-old man complained of severe pain and paresthesias following acetabular component revision surgery. Physical findings included right buttock pain with radiating pain to lower extremity. Radiographs and computed tomography imaging showed that the sharp end of protruded screw invaded greater sciatic foramen anterior to posterior and distal to proximal direction at sciatic notch level. A protruding tip of the acetabular screw at the sciatic notch was decompressed by use of techniques gained from experience performing endoscopic sciatic nerve decompression. The pre-operative pain and paresthesias resolved post-operatively after recovering from anesthesia. This case report describes the first documented endoscopic resection of the tip of the acetabular screw irritating sciatic nerve after total hip arthroplasty. If endoscopic resection of an offending acetabular screw can be performed in a safe and minimally invasive manner, one can envision a future expansion of the role of hip arthroscopic surgery in several complications management after total hip arthroplasty.

An enhanced narrow-band imaging method for the microvessel detection

Science.gov (United States)

Yu, Feng; Song, Enmin; Liu, Hong; Wan, Youming; Zhu, Jun; Hung, Chih-Cheng

2018-02-01

A medical endoscope system combined with the narrow-band imaging (NBI), has been shown to be a superior diagnostic tool for early cancer detection. The NBI can reveal the morphologic changes of microvessels in the superficial cancer. In order to improve the conspicuousness of microvessel texture, we propose an enhanced NBI method to improve the conspicuousness of endoscopic images. To obtain the more conspicuous narrow-band images, we use the edge operator to extract the edge information of the narrow-band blue and green images, and give a weight to the extracted edges. Then, the weighted edges are fused with the narrow-band blue and green images. Finally, the displayed endoscopic images are reconstructed with the enhanced narrow-band images. In addition, we evaluate the performance of enhanced narrow-band images with different edge operators. Experimental results indicate that the Sobel and Canny operators achieve the best performance of all. Compared with traditional NBI method of Olympus company, our proposed method has more conspicuous texture of microvessel.

Transsphenoidal Approach in Endoscopic Endonasal Surgery for Skull Base Lesions: What Radiologists and Surgeons Need to Know.

Science.gov (United States)

García-Garrigós, Elena; Arenas-Jiménez, Juan José; Monjas-Cánovas, Irene; Abarca-Olivas, Javier; Cortés-Vela, Jesús Julián; De La Hoz-Rosa, Javier; Guirau-Rubio, Maria Dolores

2015-01-01

In the last 2 decades, endoscopic endonasal transsphenoidal surgery has become the most popular choice of neurosurgeons and otolaryngologists to treat lesions of the skull base, with minimal invasiveness, lower incidence of complications, and lower morbidity and mortality rates compared with traditional approaches. The transsphenoidal route is the surgical approach of choice for most sellar tumors because of the relationship of the sphenoid bone to the nasal cavity below and the pituitary gland above. More recently, extended approaches have expanded the indications for transsphenoidal surgery by using different corridors leading to specific target areas, from the crista galli to the spinomedullary junction. Computer-assisted surgery is an evolving technology that allows real-time anatomic navigation during endoscopic surgery by linking preoperative triplanar radiologic images and intraoperative endoscopic views, thus helping the surgeon avoid damage to vital structures. Preoperative computed tomography is the preferred modality to show bone landmarks and vascular structures. Radiologists play an important role in surgical planning by reporting extension of sphenoid pneumatization, recesses and septations of the sinus, and other relevant anatomic variants. Radiologists should understand the relationships of the sphenoid bone and skull base structures, anatomic variants, and image-guided neuronavigation techniques to prevent surgical complications and allow effective treatment of skull base lesions with the endoscopic endonasal transsphenoidal approach. ©RSNA, 2015.

Surface nuclear magnetic resonance imaging of water content distribution in the subsurface. 1998 annual progress report

International Nuclear Information System (INIS)

Hendrickx, J.M.H.

1998-01-01

'The objective of the project is to evaluate Surface Nuclear Magnetic Resonance Imaging ( NMRI) for determining water content distribution in the subsurface. In NMRI the interaction of the magnetic moment of hydrogen ( protons) nuclei with external applied electromagnetic ( EM ) fields is measured. In surface NMRI the Earth''s magnetic field causes alignment of the spinning protons. An alternating EM field is generated by a loop of wire laid on the Earth surface. The alternating current driven through the loop at the Lamor frequency of protons in liquid water. The component of the EM field perpendicular to the Earth''s field causes a precession of protons from their equilibrium position. Water content distribution in the subsurface is derived from measurements on the EM field caused by the return of the precessing protons to equilibrium after the current in the transmitter loop is terminated. The scientific goals of the R and D are: to verify and validate the theoretical concepts and experimental results of Russian scientists, who first introduced this method; to evaluate the range of applications and limitations of this technology for practical field measurements. NMRI has the potential of providing a remote, direct, unique method for subsurface water measurements. All present methods are either intrusive or indirect ( e.g. electrical resitivity measurements). In the past year progress has been made along two separate paths. These are: (1) Field Measurements. Surface NMRI equipment manufactured by IRIS Instruments of France was tested over a number of sites with good hydrogeologic control. The results of these measurements can be summarized as follows: The NMRI measurement directly and uniquely determines water distribution in coarse grained aquifers; geologic formation from which water can be readily withdrawn. Water content can not be determined by this technique in fine grained sediments. The signal to be measured is very small and EM interference''s from power

Endoscopically assisted resection of a scapular osteochondroma causing snapping scapula syndrome

Directory of Open Access Journals (Sweden)

Futani Hiroyuki

2007-03-01

Full Text Available Abstract Background Osteochondroma is the most common benign bone tumor in the scapula. This condition might lead to snapping scapula syndrome, which is characterized by painful, audible, and/or palpable abnormal scapulothoracic motion. In the present case, this syndrome was successfully treated by use of endoscopically assisted resection of the osteochondroma. Case presentation A 41-year-old man had a tolerable pain in his scapular region over a 10 years' period. The pain developed gradually with shoulder motion, in particular with golf swing since he was aiming a professional golf player career. On physical examination, "clunking" was noted once from 90 degrees of abduction to 180 degrees of shoulder motion. A trans-scapular roentgenogram and computed tomography images revealed an osteochondroma located at the anterior and inferior aspect of the scapula. Removal of the tumor was performed by the use of endoscopically assisted resection. One portal was made at the lateral border of the scapula to introduce a 2.7-mm-diameter, 30 degrees Hopkins telescope. The tumor was resected in a piece-by-piece manner by the use of graspers through the same portal. Immediately after the operation pain relief was obtained, and the "clunking" disappeared. CT images showed complete tumor resection. The patient could start playing golf one week after the surgery. Conclusion Endoscopically assisted resection of osteochondroma of the scapula provides a feasible technique to treat snapping scapula syndrome and obtain early functional recovery with a short hospital stay and cosmetic advantage.

Spot restoration for GPR image post-processing

Science.gov (United States)

Paglieroni, David W; Beer, N. Reginald

2014-05-20

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Endoscopic foraminal decompression for failed back surgery syndrome under local anesthesia.

Science.gov (United States)

Yeung, Anthony; Gore, Satishchandra

2014-01-01

The most common causes of failed back surgery are residual or recurrent herniation, foraminal fibrosis and foraminal stenosis that is ignored, untreated, or undertreated. Residual back ache may also be from facetal causes or denervation and scarring of the paraspinal muscles.(1-6) The original surgeon may advise his patient that nothing more can be done on the basis of his opinion that the nerve was visually decompressed by the original surgery, supported by improved post-op imaging and follow-up studies such as EMG and conduction velocity studies. Post-op imaging or electrophysiological assessment may be inadequate to explain all the reasons for residual or recurrent symptoms. Treatment of Failed back surgery by repeat traditional open revision surgery usually incorporates more extensive decompression causing increased instability and back pain, therefore necessitating fusion. The authors, having limited their practice to endoscopic MIS surgery over the last 15-20 years, report on their experience gained during that period to relieve pain by endoscopically visualizing and treating unrecognized causative patho-anatomy in FBSS.(7.) Thirty consecutive patients with FBSS presenting with back and leg pain that had supporting imaging diagnosis of lateral stenosis and /or residual / recurrent disc herniation, or whose pain complaint was supported by relief from diagnostic and therapeutic injections (Figure 1), were offered percutaneous transforaminal endoscopic discectomy and foraminoplasty over a repeat open procedure. Each patient sought consultation following a transient successful, partially successful or unsuccessful open translaminar surgical treatment for disc herniation or spinal stenosis. Endoscopic foraminoplasty was also performed to either decompress the bony foramen for foraminal stenosis, or foraminoplasty to allow for endoscopic visual examination of the affected traversing and exiting nerve roots in the axilla, also known as the "hidden zone" of Macnab

Finding of biliary fascioliasis by endoscopic ultrasonography in a patient with eosinophilic liver abscess.

Science.gov (United States)

Behzad, Catherine; Lahmi, Farhad; Iranshahi, Majid; Mohammad Alizadeh, Amir Houshang

2014-09-01

Fascioliasis is an endemic zoonotic disease in Iran. It occurs mainly in sheep-rearing areas of temperate climates, but sporadic cases have been reported from many other parts of the world. The usual definitive host is the sheep. Humans are accidental hosts in the life cycle of Fasciola. Typical symptoms may be associated with fascioliasis, but in some cases diagnosis and treatment may be preceded by a long period of abdominal pain and vague gastrointestinal symptoms. We report a case with epigastric and upper quadrant abdominal pain for the last 6 months, with imaging suggesting liver abscess and normal biliary ducts. The patient had no eosinophilia with negative stool examinations, so she was initially treated with antibiotics for liver abscess. Her clinical condition as well as follow-up imagings showed appropriate response after antibiotic therapy. Finally, endoscopic ultrasonography revealed Fasciola hepatica, which was then extracted with endoscopic retrograde cholangiopancreatography.

Effect of endoscopic transpapillary biliary drainage with/without endoscopic sphincterotomy on post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with biliary stricture (E-BEST): a protocol for a multicentre randomised controlled trial.

Science.gov (United States)

Kato, Shin; Kuwatani, Masaki; Sugiura, Ryo; Sano, Itsuki; Kawakubo, Kazumichi; Ono, Kota; Sakamoto, Naoya

2017-08-11

The effect of endoscopic sphincterotomy prior to endoscopic biliary stenting to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis remains to be fully elucidated. The aim of this study is to prospectively evaluate the non-inferiority of non-endoscopic sphincterotomy prior to stenting for naïve major duodenal papilla compared with endoscopic sphincterotomy prior to stenting in patients with biliary stricture. We designed a multicentre randomised controlled trial, for which we will recruit 370 patients with biliary stricture requiring endoscopic biliary stenting from 26 high-volume institutions in Japan. Patients will be randomly allocated to the endoscopic sphincterotomy group or the non-endoscopic sphincterotomy group. The main outcome measure is the incidence of pancreatitis within 2 days of initial transpapillary biliary drainage. Data will be analysed on completion of the study. We will calculate the 95% confidence intervals (CIs) of the incidence of pancreatitis in each group and analyse weather the difference in both groups with 95% CIs is within the non-inferiority margin (6%) using the Wald method. This study has been approved by the institutional review board of Hokkaido University Hospital (IRB: 016-0181). Results will be submitted for presentation at an international medical conference and published in a peer-reviewed journal. The University Hospital Medical Information Network ID: UMIN000025727 Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Robust electromagnetically guided endoscopic procedure using enhanced particle swarm optimization for multimodal information fusion

International Nuclear Information System (INIS)

Luo, Xiongbiao; Wan, Ying; He, Xiangjian

2015-01-01

Purpose: Electromagnetically guided endoscopic procedure, which aims at accurately and robustly localizing the endoscope, involves multimodal sensory information during interventions. However, it still remains challenging in how to integrate these information for precise and stable endoscopic guidance. To tackle such a challenge, this paper proposes a new framework on the basis of an enhanced particle swarm optimization method to effectively fuse these information for accurate and continuous endoscope localization. Methods: The authors use the particle swarm optimization method, which is one of stochastic evolutionary computation algorithms, to effectively fuse the multimodal information including preoperative information (i.e., computed tomography images) as a frame of reference, endoscopic camera videos, and positional sensor measurements (i.e., electromagnetic sensor outputs). Since the evolutionary computation method usually limits its possible premature convergence and evolutionary factors, the authors introduce the current (endoscopic camera and electromagnetic sensor’s) observation to boost the particle swarm optimization and also adaptively update evolutionary parameters in accordance with spatial constraints and the current observation, resulting in advantageous performance in the enhanced algorithm. Results: The experimental results demonstrate that the authors’ proposed method provides a more accurate and robust endoscopic guidance framework than state-of-the-art methods. The average guidance accuracy of the authors’ framework was about 3.0 mm and 5.6° while the previous methods show at least 3.9 mm and 7.0°. The average position and orientation smoothness of their method was 1.0 mm and 1.6°, which is significantly better than the other methods at least with (2.0 mm and 2.6°). Additionally, the average visual quality of the endoscopic guidance was improved to 0.29. Conclusions: A robust electromagnetically guided endoscopy framework was

Robust electromagnetically guided endoscopic procedure using enhanced particle swarm optimization for multimodal information fusion.

Science.gov (United States)

Luo, Xiongbiao; Wan, Ying; He, Xiangjian

2015-04-01

Electromagnetically guided endoscopic procedure, which aims at accurately and robustly localizing the endoscope, involves multimodal sensory information during interventions. However, it still remains challenging in how to integrate these information for precise and stable endoscopic guidance. To tackle such a challenge, this paper proposes a new framework on the basis of an enhanced particle swarm optimization method to effectively fuse these information for accurate and continuous endoscope localization. The authors use the particle swarm optimization method, which is one of stochastic evolutionary computation algorithms, to effectively fuse the multimodal information including preoperative information (i.e., computed tomography images) as a frame of reference, endoscopic camera videos, and positional sensor measurements (i.e., electromagnetic sensor outputs). Since the evolutionary computation method usually limits its possible premature convergence and evolutionary factors, the authors introduce the current (endoscopic camera and electromagnetic sensor's) observation to boost the particle swarm optimization and also adaptively update evolutionary parameters in accordance with spatial constraints and the current observation, resulting in advantageous performance in the enhanced algorithm. The experimental results demonstrate that the authors' proposed method provides a more accurate and robust endoscopic guidance framework than state-of-the-art methods. The average guidance accuracy of the authors' framework was about 3.0 mm and 5.6° while the previous methods show at least 3.9 mm and 7.0°. The average position and orientation smoothness of their method was 1.0 mm and 1.6°, which is significantly better than the other methods at least with (2.0 mm and 2.6°). Additionally, the average visual quality of the endoscopic guidance was improved to 0.29. A robust electromagnetically guided endoscopy framework was proposed on the basis of an enhanced particle swarm

Robust electromagnetically guided endoscopic procedure using enhanced particle swarm optimization for multimodal information fusion

Energy Technology Data Exchange (ETDEWEB)

Luo, Xiongbiao, E-mail: xluo@robarts.ca, E-mail: Ying.Wan@student.uts.edu.au [Robarts Research Institute, Western University, London, Ontario N6A 5K8 (Canada); Wan, Ying, E-mail: xluo@robarts.ca, E-mail: Ying.Wan@student.uts.edu.au; He, Xiangjian [School of Computing and Communications, University of Technology, Sydney, New South Wales 2007 (Australia)

2015-04-15

Purpose: Electromagnetically guided endoscopic procedure, which aims at accurately and robustly localizing the endoscope, involves multimodal sensory information during interventions. However, it still remains challenging in how to integrate these information for precise and stable endoscopic guidance. To tackle such a challenge, this paper proposes a new framework on the basis of an enhanced particle swarm optimization method to effectively fuse these information for accurate and continuous endoscope localization. Methods: The authors use the particle swarm optimization method, which is one of stochastic evolutionary computation algorithms, to effectively fuse the multimodal information including preoperative information (i.e., computed tomography images) as a frame of reference, endoscopic camera videos, and positional sensor measurements (i.e., electromagnetic sensor outputs). Since the evolutionary computation method usually limits its possible premature convergence and evolutionary factors, the authors introduce the current (endoscopic camera and electromagnetic sensor’s) observation to boost the particle swarm optimization and also adaptively update evolutionary parameters in accordance with spatial constraints and the current observation, resulting in advantageous performance in the enhanced algorithm. Results: The experimental results demonstrate that the authors’ proposed method provides a more accurate and robust endoscopic guidance framework than state-of-the-art methods. The average guidance accuracy of the authors’ framework was about 3.0 mm and 5.6° while the previous methods show at least 3.9 mm and 7.0°. The average position and orientation smoothness of their method was 1.0 mm and 1.6°, which is significantly better than the other methods at least with (2.0 mm and 2.6°). Additionally, the average visual quality of the endoscopic guidance was improved to 0.29. Conclusions: A robust electromagnetically guided endoscopy framework was

Development of EndoTOFPET-US, a multi-modal endoscope for ultrasound and time of flight positron emission tomography

International Nuclear Information System (INIS)

Pizzichemi, M

2014-01-01

The EndoTOFPET-US project aims at delevoping a multi-modal imaging device that combines Ultrasound with Time-Of-Flight Positron Emission Tomography into an endoscopic imaging device. The goal is to obtain a coincidence time resolution of about 200 ps FWHM and sub-millimetric spatial resolution for the PET head, integrating the components in a very compact detector suitable for endoscopic use. The scanner will be exploited for the clinical test of new bio-markers especially targeted for prostate and pancreatic cancer as well as for diagnostic and surgical oncology. This paper focuses on the status of the Time-Of-Flight Positron Emission Tomograph under development for the EndoTOFPET-US project

An Unusual Endoscopic Image of a Submucosal Angiodysplasia

Directory of Open Access Journals (Sweden)

Rita Carvalho

2012-01-01

Full Text Available Obscure gastrointestinal bleeding is responsible for 2–10% of the cases of digestive bleeding. Angiodysplasia is the most common cause. The authors report a case of a 70-year-old female patient admitted to our Gastrointestinal Intensive Care Unit with a significant digestive bleeding. Standard upper and lower endoscopy showed no abnormalities, and we decided to perform a capsule enteroscopy that revealed a submucosal nodule with active bleeding in the jejunum. An intraoperative enteroscopy confirmed the presence of a small submucosal lesion with a central ulceration, and subsequently a segmental enterectomy was performed. Surprisingly, the histopathological diagnosis was angiodysplasia. The patient remains well after a two-year period of follow-up. We present this case of obscure/overt gastrointestinal bleeding to emphasize the role of capsule and intraoperative enteroscopy in the evaluation of these situations, and because of the unusual endoscopic appearance of the angiodysplasia responsible for the hemorrhage.

Composition and structure of the shallow subsurface of Ceres revealed by crater morphology

Science.gov (United States)

Bland, Michael T.; Carol A. Raymond,; Schenk, Paul M.; Roger R. Fu,; Thomas Kneisl,; Hendrick Pasckert, Jan; Hiesinger, Harald; Frank Preusker,; Ryan S. Park,; Simone Marchi,; Scott King,; Castillo-Rogez, Julie C.; Christopher T. Russell,

2016-01-01

Before NASA’s Dawn mission, the dwarf planet Ceres was widely believed to contain a substantial ice-rich layer below its rocky surface. The existence of such a layer has significant implications for Ceres’s formation, evolution, and astrobiological potential. Ceres is warmer than icy worlds in the outer Solar System and, if its shallow subsurface is ice-rich, large impact craters are expected to be erased by viscous flow on short geologic timescales. Here we use digital terrain models derived from Dawn Framing Camera images to show that most of Ceres’s largest craters are several kilometres deep, and are therefore inconsistent with the existence of an ice-rich subsurface. We further show from numerical simulations that the absence of viscous relaxation over billion-year timescales implies a subsurface viscosity that is at least one thousand times greater than that of pure water ice. We conclude that Ceres’s shallow subsurface is no more than 30% to 40% ice by volume, with a mixture of rock, salts and/or clathrates accounting for the other 60% to 70%. However, several anomalously shallow craters are consistent with limited viscous relaxation and may indicate spatial variations in subsurface ice content.

New techniques in gastrointestinal endoscopic surgery

Directory of Open Access Journals (Sweden)

Rafael Antonio Luengas Tello

2012-09-01

Full Text Available Gastrointestinal endoscopic surgery has been making great progress since the seventies in the management paradigms of conditions such as gastrointestinal bleeding, polyp resection and diagnostic and therapeutic management of the biliary tract. The current challenge is the development of techniques that allow endoscopic treatment of emerging diseases such as cancer, morbid obesity, gastro-esophageal reflux and achalasia. This article reports on new techniques and expectations for the future in the endoscopic management of these diseases.

[Natural Orifice Transluminal Endoscopic Surgery (NOTES)].

Science.gov (United States)

Kim, Yong Sik; Kim, Chul Young; Chun, Hoon Jai

2008-03-01

Recently, the field of gastrointestinal endoscopy is developing rapidly. Once limited to the gastroinstestinal lumen, the endoscopic technology is now breaking the barriers and extending its boundary to peritoneal and pleural space. In 2004, Dr. Kalloo, a gastroenterologist, observed intraperitoneal organs of a pig using a conventional endoscope through the stomach wall. Since then, new endoscopic technique of intraperitoneal intervention with transluminal approach named the Natural Orifice Transluminal Endoscopic Surgery or NOTES has been introduced. NOTES reaches the target organ by inserting the endoscope through a natural orifice (e.g. mouth, anus, vagina, urethra) and entering the peritoneal lumen by means of making an incision on the luminal wall. After a series of successful experiences in animal studies, NOTES are now being tried on human subjects. There are still many obstacles to overcome, but bright future for this new technology is expected because of its proposed advantages of less pain, lower complication rate, short recovery time, and scarless access. In this review, we plan to learn about NOTES.

[Tracheotomy-endoscop for dilatational percutaneous tracheotomy (TED)].

Science.gov (United States)

Klemm, Eckart

2006-09-01

While surgical tracheotomies are currently performed using state-of-the-art operative techniques, percutaneous dilatational tracheostomy (PDT) is in a rapidly evolving state with regard to its technology and the number of techniques available. This has resulted in a range of new complications that are difficult to quantify on a scientific basis, given the fact that more than half of the patients who are tracheotomized in intensive care units die from their underlying disease. The new Tracheotomy Endoscope (TED) is designed to help prevent serious complications in dilatational tracheotomies and facilitate their management. The endoscope has been specifically adapted to meet the require-ments of percutaneous dilatational tracheotomies. It is fully compatible with all current techniques of PDT. The method is easy to learn. The percutaneous dilatational tracheotomy with the Tracheotomy Endoscope is a seven-step procedure: Advantages of the Tracheotomy Endoscope: Injuries to the posterior tracheal wall ar impossible (tracheoesophageal fistulas, pneumothorax). Minor bleeding sites on the tracheal mucosa can be controlled with a specially curved suction-coagulation tube introudeced through the Tracheotomy Endoscope. In cases with heavy bleeding and a risk of aspiration, the rigid indwelling Tracheotomy Endoscope provides a secure route for reintubating the patient with a cuffed endotracheal tube. It also allows for rapid conversion to an open surgical procedure if necessary. All the parts are easy to clean and are autoclavable. This type of endoscopically guided PDT creates an optimal link between the specialties of intensive care medicine and otorhinolaryngology. The Tracheotomy Endoscope (TED) increases the standard of safety in PDT.

The Lusi eruption site: insights from surface and subsurface investigations

Science.gov (United States)

Mazzini, A.

2017-12-01

The Indonesian Lusi eruption has been spewing boiling water, gas, and sediments since the 29th of May 2006. Initially, numerous aligned eruptions sites appeared along the Watukosek fault system (WFS) that was reactivated after the Yogyakarta earthquake occurring the 27th of May in the Java Island. Within weeks several villages were submerged by boiling mud. The most prominent eruption site was named Lusi. To date Lusi is still active and an area of 7 km2is covered by mud. Since its birth Lusi erupted with a pulsating behaviour. In the framework of the ERC grant "Lusi Lab" we conducted several years of monitoring and regional investigations coupling surface sampling and subsurface imaging in the region around Lusi. Ambient noise tomography studies, obtained with a local network of 31 stations, revealed for the first time subsurface images of the Lusi region and the adjacent Arjuno-Welirang (AW) volcanic complex. Results show that below the AW volcanic complex are present 5km deep magma chambers that are connected, through a defined corridor, with the roots of the Lusi eruption site. The Lusi subsurface shows the presence of a defined vertical hydrothermal plume that extends to at least 5km. Chemical analyses of the seeping fluids sampled from 1) the Lusi plume (using a specifically designed drone), 2) the region around Lusi, and 3) the fumaroles and the hydro thermal springs of AW, revealed striking similarities. More specifically a mantellic signature of the Lusi fluids confirms the scenario that Lusi represents a magmatic-driven hydrothermal system hosted in sedimentary basin. Seismic profiles interpretation, surface mapping, and fluid sampling show that the WFS, connecting AW and extending towards the NE of Java, acted as a preferential pathway for the igneous intrusion and fluids migration towards the subsurface. Petrography and dating of the clasts erupted at Lusi record high temperatures and indicate that the roots of the active conduit extend to at least 5km

Ultrahigh speed endoscopic swept source optical coherence tomography using a VCSEL light source and micromotor catheter

Science.gov (United States)

Tsai, Tsung-Han; Ahsen, Osman O.; Lee, Hsiang-Chieh; Liang, Kaicheng; Giacomelli, Michael G.; Potsaid, Benjamin M.; Tao, Yuankai K.; Jayaraman, Vijaysekhar; Kraus, Martin F.; Hornegger, Joachim; Figueiredo, Marisa; Huang, Qin; Mashimo, Hiroshi; Cable, Alex E.; Fujimoto, James G.

2014-03-01

We developed an ultrahigh speed endoscopic swept source optical coherence tomography (OCT) system for clinical gastroenterology using a vertical-cavity surface-emitting laser (VCSEL) and micromotor based imaging catheter, which provided an imaging speed of 600 kHz axial scan rate and 8 μm axial resolution in tissue. The micromotor catheter was 3.2 mm in diameter and could be introduced through the 3.7 mm accessory port of an endoscope. Imaging was performed at 400 frames per second with an 8 μm spot size using a pullback to generate volumetric data over 16 mm with a pixel spacing of 5 μm in the longitudinal direction. Three-dimensional OCT (3D-OCT) imaging was performed in patients with a cross section of pathologies undergoing standard upper and lower endoscopy at the Veterans Affairs Boston Healthcare System (VABHS). Patients with Barrett's esophagus, dysplasia, and inflammatory bowel disease were imaged. The use of distally actuated imaging catheters allowed OCT imaging with more flexibility such as volumetric imaging in the terminal ileum and the assessment of the hiatal hernia using retroflex imaging. The high rotational stability of the micromotor enabled 3D volumetric imaging with micron scale volumetric accuracy for both en face and cross-sectional imaging. The ability to perform 3D OCT imaging in the GI tract with microscopic accuracy should enable a wide range of studies to investigate the ability of OCT to detect pathology as well as assess treatment response.

Gastroesophageal reflux disease. Scintigraphic, endoscopic and histologic considerations

Energy Technology Data Exchange (ETDEWEB)

Kault, B.; Halvorsen, T.; Petersen, H.; Grette, K.; Myrvold, H.E.

1986-01-01

Radionucleotide scintigraphy and esophagoscopy with biopsy were carried out in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. GER was visualized by scintigraphy in 86.1% of the patients. Endoscopic and histologic esophagitis were found in 68.1% and 58.4% of the patients, respectively, whereas both examinations taken together showed evidence of esophagitis in 82%. Histologic evidence of esophagitis was found in nearly all patients with severe endoscopic changes, and in 43.7% of the patients with no endoscopic abnormality. Scintigraphic reflux was demonstrated more frequently in the patients with severe endoscopic esophagitis (97.5%) than in those with no or only mild endoscopic changes (78.6%). Scintigraphic reflux was found in 91.5% and 78.5% of the patients with and without histologic evidence of esophagitis. 15 of the 18 patients (83.3%) without endoscopic and histologic abnormalities in the esophagus had scintigraphic evidence of reflux. The present study strongly supports the clinical significance of scintigraphy in GER disease and confirms that esophageal biopsy specimens increase the sensitivity of endoscopic evaluation. 31 refs.

Anatomic variants of interest in endoscopic sinus surgery: role of computed tomography

International Nuclear Information System (INIS)

Alonso, S.; Arenas, J.; Fernandez, F.; Gil, S.; Guirau, M. D.

2000-01-01

The detailed radiological study of the anatomy of the nasal cavities and paranasal sinus is essential prior to endoscopic sinus surgery since, on the one hand, it discloses the extent of the disease and, on the other hand, it aids in the detection of the numerous anatomic variants, some of which are of great interest to the endoscopic as the lack of preoperative knowledge of them may increase the risk of complications. the objective of the present report is to review these variants, stressing those that may be associated with a greater surgical risk. Although coronal computed tomography is the technique of choice for pre endoscopy examination, certain structures and anatomic variants are better viewed in axial images. These exceptions include anterior and posterior walls of the frontal sinuses, the anatomic relationships between posterior ethmoid complex and the sphenoid sinus, the relationships between the sphenoid sinus and the optic nerve, and the detection of Onodi cells. Thus, we recommend that the radiological examination include both coronal and axial images. (Author) 16 refs

Fiber Optic Bragg Grating Sensors for Thermographic Detection of Subsurface Anomalies

Science.gov (United States)

Allison, Sidney G.; Winfree, William P.; Wu, Meng-Chou

2009-01-01

Conventional thermography with an infrared imager has been shown to be an extremely viable technique for nondestructively detecting subsurface anomalies such as thickness variations due to corrosion. A recently developed technique using fiber optic sensors to measure temperature holds potential for performing similar inspections without requiring an infrared imager. The structure is heated using a heat source such as a quartz lamp with fiber Bragg grating (FBG) sensors at the surface of the structure to detect temperature. Investigated structures include a stainless steel plate with thickness variations simulated by small platelets attached to the back side using thermal grease. A relationship is shown between the FBG sensor thermal response and variations in material thickness. For comparison, finite element modeling was performed and found to agree closely with the fiber optic thermography results. This technique shows potential for applications where FBG sensors are already bonded to structures for Integrated Vehicle Health Monitoring (IVHM) strain measurements and can serve dual-use by also performing thermographic detection of subsurface anomalies.

3D Endoscope to Boost Safety, Cut Cost of Surgery

Science.gov (United States)

2015-01-01

Researchers at the Jet Propulsion Laboratory worked with the brain surgeon who directs the Skull Base Institute in Los Angeles to create the first endoscope fit for brain surgery and capable of producing 3D video images. It is also the first to be able to steer its lens back and forth. These improvements to visibility are expected to improve safety, speeding patient recovery and reducing medical costs.

Imaging the Antarctic Ice Sheet Subsurface with the HF GPR TAPIR

Science.gov (United States)

Le Gall, A.; Ciarletti, V.; Berthelier, J.; Reineix, A.; Ney, R.; Bonaimé, S.; Corbel, C.

2006-12-01

An HF impulse polarimetric Ground Penetrating Radar (GPR) operating at very low frequencies (ranging from ~2 to 8MHz) has been developed in the frame of the NetLander mission. This instrument, named TAPIR (Terrestrial And Planetary Investigation by Radar), was designed to probe the Martian subsurface down to kilometric depth and search for potential water reservoirs. Although the NetLander mission was cancelled in 2003, the interest on the exploration of Martian subsurface was recently enhanced by the promising observations of the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) on board of the ESA Mars Express orbiter. In particular, MARSIS detected the base of the North Polar Layered Deposits, penetrating up to ~1.8km the ice-rich upper layer of the underground. Such results suggest that TAPIR, which operates in the same frequency range as MARSIS and can performed a higher number of coherent integrations, is able to reach deeper structures. Yet, in contrast with classical GPRs, TAPIR can not move onto the surface and thus won't provide 2D or 3D scan of the subsurface. To retrieve, in spite of this NetLander restraint, the 3D distribution of the reflecting facets of the underground, the instrument was equipped with two electrical dipoles and a rotating magnetic sensor. These antennas allow to derive, from the measured values of 5 components of the wave field, the direction of arrival of the reflected waves hence the inclination of the buried reflectors. The first validation of this innovative concept was carried out during the RANETA (RAdar of NEtlander in Terre Adélie) campaign organized by the Institute Paul-Emile Victor in January-February 2004. This campaign took place on the Antarctic ice sheet close to the French-Italian Cap Prudhomme station. 8 soundings of the ice shelf were performed on various sites corresponding to different altitudes above the sea level (ranging from ~285m to ~1100m). We shall provide a detailed description of the

Spatial resolution and the geologic interpretation of Martian morphology - implications for subsurface volatiles

International Nuclear Information System (INIS)

Zimbelman, J.R.

1987-01-01

Viking Orbiter images of the Acheron Fossae on Mars are presented and analyzed, with an emphasis on the impact of image resolution on the interpretation. High-resolution (less than 10 m/pixel) images reveal small mounds which can be interpreted as aeolian dunes, but these features are not evident on images with resolution of 50 m/pixel or greater. Also reported are the results of a visual inspection of 527 usable high-resolution images: it is found that all of the morphological features identified can arise in the absence of subsurface volatiles. 21 references

Endoscopic optical coherence tomography with a modified microelectromechanical systems mirror for detection of bladder cancers

Science.gov (United States)

Xie, Tuqiang; Xie, Huikai; Fedder, Gary K.; Pan, Yingtian

2003-11-01

Experimental results of a modified micromachined microelectromechanical systems (MEMS) mirror for substantial enhancement of the transverse laser scanning performance of endoscopic optical coherence tomography (EOCT) are presented. Image distortion due to buckling of MEMS mirror in our previous designs was analyzed and found to be attributed to excessive internal stress of the transverse bimorph meshes. The modified MEMS mirror completely eliminates bimorph stress and the resultant buckling effect, which increases the wobbling-free angular optical actuation to greater than 37°, exceeding the transverse laser scanning requirements for EOCT and confocal endoscopy. The new optical coherence tomography (OCT) endoscope allows for two-dimensional cross-sectional imaging that covers an area of 4.2 mm × 2.8 mm (limited by scope size) and at roughly 5 frames/s instead of the previous area size of 2.9 mm × 2.8 mm and is highly suitable for noninvasive and high-resolution imaging diagnosis of epithelial lesions in vivo. EOCT images of normal rat bladders and rat bladder cancers are compared with the same cross sections acquired with conventional bench-top OCT. The results clearly demonstrate the potential of EOCT for in vivo imaging diagnosis and precise guidance for excisional biopsy of early bladder cancers.

Endoscopic optical coherence tomography with a focus-adjustable probe.

Science.gov (United States)

Liao, Wenchao; Chen, Tianyuan; Wang, Chengming; Zhang, Wenxin; Peng, Zhangkai; Zhang, Xiao; Ai, Shengnan; Fu, Deyong; Zhou, Tieying; Xue, Ping

2017-10-15

We present a focus-adjustable endoscopic probe for optical coherence tomography (OCT), which is able to acquire images with different focal planes and overcome depth-of-focus limitations by image fusing. The use of a two-way shape-memory-alloy spring enables the probe to adjust working distance over 1.5 mm, providing a large scanning range with high resolution and no sensitivity loss. Equipped with a homemade hollow-core ultrasonic motor, the probe is capable of performing an unobstructed 360 deg field-of-view distal scanning. Both the axial resolution and the best lateral resolution are ∼4  μm, with a sensitivity of 100.3 dB. Spectral-domain OCT imaging of phantom and biological tissues with the probe is also demonstrated.

Endoscopic treatment of vesicoureteral reflux in pediatric patients

Directory of Open Access Journals (Sweden)

Jong Wook Kim

2013-04-01

Full Text Available Endoscopic treatment is a minimally invasive treatment for managing patients with vesicoureteral reflux (VUR. Although several bulking agents have been used for endoscopic treatment, dextranomer/hyaluronic acid is the only bulking agent currently approved by the U.S. Food and Drug Administration for treating VUR. Endoscopic treatment of VUR has gained great popularity owing to several obvious benefits, including short operative time, short hospital stay, minimal invasiveness, high efficacy, low complication rate, and reduced cost. Initially, the success rates of endoscopic treatment have been lower than that of open antireflux surgery. However, because injection techniques have been developed, a recent study showed higher success rates of endoscopic treatment than open surgery in the treatment of patients with intermediate- and high-grade VUR. Despite the controversy surrounding its effectiveness, endoscopic treatment is considered a valuable treatment option and viable alternative to long-term antibiotic prophylaxis.

High-resolution subsurface imaging and neural network recognition: Non-intrusive buried substance location. Final report

Energy Technology Data Exchange (ETDEWEB)

Sternberg, B.K.; Poulton, M.M.

1997-01-26

A high-frequency, high-resolution electromagnetic (EM) imaging system has been developed for environmental geophysics surveys. Some key features of this system include: (1) rapid surveying to allow dense spatial sampling over a large area, (2) high-accuracy measurements which are used to produce a high-resolution image of the subsurface, (3) measurements which have excellent signal-to-noise ratio over a wide bandwidth (31 kHz to 32 MHz), (4) elimination of electric-field interference at high frequencies, (5) large-scale physical modeling to produce accurate theoretical responses over targets of interest in environmental geophysics surveys, (6) rapid neural network interpretation at the field site, and (7) visualization of complex structures during the survey. Four major experiments were conducted with the system: (1) Data were collected for several targets in our physical modeling facility. (2) The authors tested the system over targets buried in soil. (3) The authors conducted an extensive survey at the Idaho National Engineering Laboratory (INEL) Cold Test Pit (CTP). The location of the buried waste, category of waste, and thickness of the clay cap were successfully mapped. (4) The authors ran surveys over the acid pit at INEL. This was an operational survey over a hot site. The interpreted low-resistivity region correlated closely with the known extent of the acid pit.

High-resolution subsurface imaging and neural network recognition: Non-intrusive buried substance location. Final report

International Nuclear Information System (INIS)

Sternberg, B.K.; Poulton, M.M.

1997-01-01

A high-frequency, high-resolution electromagnetic (EM) imaging system has been developed for environmental geophysics surveys. Some key features of this system include: (1) rapid surveying to allow dense spatial sampling over a large area, (2) high-accuracy measurements which are used to produce a high-resolution image of the subsurface, (3) measurements which have excellent signal-to-noise ratio over a wide bandwidth (31 kHz to 32 MHz), (4) elimination of electric-field interference at high frequencies, (5) large-scale physical modeling to produce accurate theoretical responses over targets of interest in environmental geophysics surveys, (6) rapid neural network interpretation at the field site, and (7) visualization of complex structures during the survey. Four major experiments were conducted with the system: (1) Data were collected for several targets in our physical modeling facility. (2) The authors tested the system over targets buried in soil. (3) The authors conducted an extensive survey at the Idaho National Engineering Laboratory (INEL) Cold Test Pit (CTP). The location of the buried waste, category of waste, and thickness of the clay cap were successfully mapped. (4) The authors ran surveys over the acid pit at INEL. This was an operational survey over a hot site. The interpreted low-resistivity region correlated closely with the known extent of the acid pit

SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

International Nuclear Information System (INIS)

Randle, D.C.

2000-01-01

The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I andC) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I andC and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I andC systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I andC systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored

Endoscopic versus surgical drainage treatment of calcific chronic pancreatitis.

Science.gov (United States)

Jiang, Li; Ning, Deng; Cheng, Qi; Chen, Xiao-Ping

2018-04-21

Endoscopic therapy and surgery are both conventional treatments to remove pancreatic duct stones that developed during the natural course of chronic pancreatitis. However, few studies comparing the effect and safety between surgery drainage and endoscopic drainage (plus Extracorporeal Shock Wave Lithotripsy, ESWL).The aim of this study was to compare the benefits between endoscopic and surgical drainage of the pancreatic duct for patients with calcified chronic pancreatitis. A total of 86 patients were classified into endoscopic/ESWL (n = 40) or surgical (n = 46) treatment groups. The medical records of these patients were retrospectively analyzed. Pain recurrence and hospital stays were similar between the endoscopic/ESWL treatment and surgery group. However, endoscopic/ESWL treatment yielded significantly lower medical expense and less complications compared with the surgical treatment. In selective patients, endoscopic/ESWL treatment could achieve comparable efficacy to the surgical treatment. With lower medical expense and less complications, endoscopic/ESWL treatment would be much preferred to be the initial treatment of choice for patients with calcified chronic pancreatitis. Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Asymptomatic Esophageal Varices Should Be Endoscopically Treated

Directory of Open Access Journals (Sweden)

Nib Soehendra

1998-01-01

Full Text Available Endoscopic treatment has generally been accepted in the management of bleeding esophageal varices. Both the control of acute variceal bleeding and elective variceal eradication to prevent recurrent bleeding can be achieved via endoscopic methods. In contrast to acute and elective treatment, the role of endoscopic therapy in asymptomatic patients who have never had variceal bleeding remains controversial because of the rather disappointing results obtained from prophylactic sclerotherapy. Most published randomized controlled trials showed that prophylactic sclerotherapy had no effect on survival. In some studies, neither survival rate nor bleeding risk was improved. In this article, the author champions the view that asymptomatic esophageal varices should be endoscopically treated.

Synthetic aperture integration (SAI) algorithm for SAR imaging

Science.gov (United States)

Chambers, David H; Mast, Jeffrey E; Paglieroni, David W; Beer, N. Reginald

2013-07-09

A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Endoscopic Management of an Intramural Sinus Leak After Per- Oral Endoscopic Myotomy

Science.gov (United States)

Al Taii, Haider; Confer, Bradley; Gabbard, Scott; Kroh, Matthew; Jang, Sunguk; Rodriguez, John; Parsi, Mansour A.; Vargo, John J.; Ponsky, Jeffrey

2016-01-01

Per-oral endoscopic myotomy (POEM) was developed less than a decade ago for the treatment of achalasia. Its minimally invasive approach and the favorable short-term outcome have led to rapid adoption of the technique throughout the world. As with any new technique, there will be adverse events, and it is important that effective treatments for these adverse events be discussed. We present a case of successful endoscopic management of an intramural sinus leak after a POEM procedure using tandem fully covered esophageal stents. PMID:27921057

Thematic survey of subsurface drainage systems in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Tlapáková, L.; Žaloudík, J.; Kolejka, Jaromír

2016-01-01

Roč. 13, č. 2 (2016), s. 55-65 ISSN 1744-5647 Institutional support: RVO:68145535 Keywords : subsurface drainage system * remote sensing * image interpretation * drainage recognition and mapping Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 2.174, year: 2016 http://www.tandfonline.com/doi/full/10.1080/17445647.2016.1259129?scroll=top&needAccess=true

Integrated approach to 3-D seismic acquisition geometry analysis : Emphasizing the influence of the inhomogeneous subsurface

NARCIS (Netherlands)

van Veldhuizen, E.J.

2006-01-01

The seismic reflection method for imaging of the earth's interior is an essential part of the exploration and exploitation of hydrocarbon resources. A seismic survey should be designed such that the acquired data leads to a sufficiently accurate subsurface image. The survey geometry analysis method

Endoscopic versus open bursectomy of lateral malleolar bursitis.

Science.gov (United States)

Choi, Jae Hyuck; Lee, Kyung Tai; Lee, Young Koo; Kim, Dong Hyun; Kim, Jeong Ryoul; Chung, Woo Chull; Cha, Seung Do

2012-06-01

Compare the result of endoscopic versus open bursectomy in lateral malleolar bursitis. Prospective evaluation of 21 patients (22 ankles) undergoing either open or endoscopic excision of lateral malleolar bursitis. The median age was 64 (38-79) years old. The median postoperative follow-up was 15 (12-18) months. Those patients undergoing endoscopic excision showed a higher satisfaction rate (excellent 9, good 2) than open excision (excellent 4, good 3, fair 1). The wounds also healed earlier in the endoscopic group although the operation time was slightly longer. One patient in the endoscopic group had recurrence of symptoms but complications in the open group included one patient with skin necrosis, one patient with wound dehiscence, and two patients of with superficial peroneal nerve injury. Endoscopic resection of the lateral malleolar bursitis is a promising technique and shows favorable results compared to the open resection. Therapeutic studies-Investigating the result of treatment, Level II.

Detecting Subsurface Agricultural Tile Drainage using GIS and Remote Sensing Technique

Science.gov (United States)

Budhathoki, M.; Gokkaya, K.; Tank, J. L.; Christopher, S. F.; Hanrahan, B.

2015-12-01

Subsurface tile drainage is a common practice in many of the row crop dominated agricultural lands in the Upper Midwest, which increases yield by making the soil more productive. It is reported that nearly half of all cropland in Indiana benefits from some sort of artificial drainage. However, subsurface tile has a significant negative impact on surface water quality by providing a fast means of transport for nutrients from fertilizers. Therefore, generating spatial data of tile drainage in the field is important and useful for agricultural landscape and hydrological studies. Subsurface tile drains in Indiana's croplands are not widely mapped. In this study, we will delineate subsurface tile drainage in agricultural land in Shatto Ditch watershed, located in Kosciusko County, Indiana. We will use geo-spatial methodology, which was purposed by earlier researchers to detect tile drainage. We will use aerial color-infrared and satellite imagery along with Light Detection and Ranging (LiDAR) data. In order to map tile lines with possible accuracy, we will use GIS-based analysis in combination with remotely sensed data. This research will be comprised of three stages: 1) masking out the potential drainage area using a decision tree rule based on land cover information, soil drainage category, surface slope, and satellite image differencing technique, 2) delineate tile lines using image processing techniques, and 3) check the accuracy of mapped tile lines with ground control points. To our knowledge, this study will be the first to check the accuracy of mapping with ground truth data. Based on the accuracy of results, we will extend the methodology to greater spatial scales. The results are expected to contribute to better characterizing and controlling water pollution sources in Indiana, which is a major environmental problem.

Fully wireless pressure sensor based on endoscopy images

Science.gov (United States)

Maeda, Yusaku; Mori, Hirohito; Nakagawa, Tomoaki; Takao, Hidekuni

2018-04-01

In this paper, the result of developing a fully wireless pressure sensor based on endoscopy images for an endoscopic surgery is reported for the first time. The sensor device has structural color with a nm-scale narrow gap, and the gap is changed by air pressure. The structural color of the sensor is acquired from camera images. Pressure detection can be realized with existing endoscope configurations only. The inner air pressure of the human body should be measured under flexible-endoscope operation using the sensor. Air pressure monitoring, has two important purposes. The first is to quantitatively measure tumor size under a constant air pressure for treatment selection. The second purpose is to prevent the endangerment of a patient due to over transmission of air. The developed sensor was evaluated, and the detection principle based on only endoscopy images has been successfully demonstrated.

A 3D scanning laser endoscope architecture utilizing a circular piezoelectric membrane

Science.gov (United States)

Khayatzadeh, Ramin; Çivitci, Fehmi; Ferhanoğlu, Onur

2017-12-01

A piezo-scanning fiber endoscopic device architecture is proposed for 3D imaging or ablation. The endoscopic device consists of a piezoelectric membrane that is placed perpendicular to the optical axis, a fiber optic cable that extends out from and actuated by the piezoelectric membrane, and one or multiple lenses for beam delivery and collection. Unlike its counterparts that utilize piezoelectric cylinders for fiber actuation, the proposed architecture offers quasi-static actuation in the axial direction along with resonant actuation in the lateral directions forming a 3D scanning pattern, allowing adjustment of the focus plane. The actuation of the four-quadrant piezoelectric membrane involves driving of two orthogonal electrodes with AC signals for lateral scanning, while simultaneously driving all electrodes for axial scanning and focus adjustment. We have characterized piezoelectric membranes (5 -15mm diameter) with varying sizes to monitor axial displacement behavior with respect to applied DC voltage. We also demonstrate simultaneous lateral and axial actuation on a resolution target, and observe the change of lateral resolution on a selected plane through performing 1D cross-sectional images, as an indicator of focal shift through axial actuation. Based on experimental results, we identify the optical and geometrical parameters for optimal 3D imaging of tissue samples. Our findings reveal that a simple piezoelectric membrane, having comparable dimensions and drive voltage requirement with off-the-shelf MEMS scanner chips, offers tissue epithelial imaging with sub-cellular resolution.

Contrast-enhanced endoscopic ultrasonography

DEFF Research Database (Denmark)

Reddy, Nischita K; Ioncica, Ana Maria; Saftoiu, Adrian

2011-01-01

Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...

Is endoscopic nodular gastritis associated with premalignant lesions?

Science.gov (United States)

Niknam, R; Manafi, A; Maghbool, M; Kouhpayeh, A; Mahmoudi, L

2015-06-01

Nodularity on the gastric mucosa is occasionally seen in general practice. There is no consensus about the association of nodular gastritis and histological premalignant lesions. This study is designed to investigate the prevalence of histological premalignant lesions in dyspeptic patients with endoscopic nodular gastritis. Consecutive patients with endoscopic nodular gastritis were compared with an age- and sex-matched control group. Endoscopic nodular gastritis was defined as a miliary nodular appearance of the gastric mucosa on endoscopy. Biopsy samples of stomach tissue were examined for the presence of atrophic gastritis, intestinal metaplasia, and dysplasia. The presence of Helicobacter pylori infection was determined by histology. From 5366 evaluated patients, a total of 273 patients with endoscopic nodular gastritis and 1103 participants as control group were enrolled. H. pylori infection was detected in 87.5% of the patients with endoscopic nodular gastritis, whereas 73.8% of the control group were positive for H. pylori (p gastritis were significantly higher than in the control group. Prevalence of atrophic gastritis and complete intestinal metaplasia were also more frequent in patients with endoscopic nodular gastritis than in the control group. Dysplasia, incomplete intestinal metaplasia and H. pylori infection are significantly more frequent in patients with endoscopic nodular gastritis. Although further studies are needed before a clear conclusion can be reached, we suggest that endoscopic nodular gastritis might serve as a premalignant lesion and could be biopsied in all patients for the possibility of histological premalignancy, in addition to H. pylori infection.

Subsurface clade of Geobacteraceae that predominates in a diversity of Fe(III)-reducing subsurface environments

Science.gov (United States)

Holmes, Dawn E.; O'Neil, Regina A.; Vrionis, Helen A.; N'Guessan, Lucie A.; Ortiz-Bernad, Irene; Larrahondo, Maria J.; Adams, Lorrie A.; Ward, Joy A.; Nicoll , Julie S.; Nevin, Kelly P.; Chavan, Milind A.; Johnson, Jessica P.; Long, Philip E.; Lovely, Derek R.

2007-01-01

There are distinct differences in the physiology of Geobacter species available in pure culture. Therefore, to understand the ecology of Geobacter species in subsurface environments, it is important to know which species predominate. Clone libraries were assembled with 16S rRNA genes and transcripts amplified from three subsurface environments in which Geobacter species are known to be important members of the microbial community: (1) a uranium-contaminated aquifer located in Rifle, CO, USA undergoing in situ bioremediation; (2) an acetate-impacted aquifer that serves as an analog for the long-term acetate amendments proposed for in situ uranium bioremediation and (3) a petroleum-contaminated aquifer in which Geobacter species play a role in the oxidation of aromatic hydrocarbons coupled with the reduction of Fe(III). The majority of Geobacteraceae 16S rRNA sequences found in these environments clustered in a phylogenetically coherent subsurface clade, which also contains a number of Geobacter species isolated from subsurface environments. Concatamers constructed with 43 Geobacter genes amplified from these sites also clustered within this subsurface clade. 16S rRNA transcript and gene sequences in the sediments and groundwater at the Rifle site were highly similar, suggesting that sampling groundwater via monitoring wells can recover the most active Geobacter species. These results suggest that further study of Geobacter species in the subsurface clade is necessary to accurately model the behavior of Geobacter species during subsurface bioremediation of metal and organic contaminants.

Development of a fluorescence endoscopic system for pH mapping of gastric tissue

Science.gov (United States)

Rochon, Philippe; Mordon, Serge; Buys, Bruno; Dhelin, Guy; Lesage, Jean C.; Chopin, Claude

2003-10-01

Measurement of gastro intestinal intramucosal pH (pHim) has been recognized as an important factor in the detection of hypoxia induced dysfonctions. However, current pH measurements techniques are limited in terms of time and spatial resolutions. A major advance in accurate pH measurement was the development of the ratiometric fluorescent indicator dye, 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). BCECF which pKa is in the physiological pH range is suitable for pH tissue measurements in vivo. This study aimed to develop and evaluate an endoscopic imaging system for real time pH measurements in the stomach in order to provide to ICU a new tool for gastro intestinal intramucosal pH (pHim) measurements. This fluorescence imaging technique should allow the temporal exploration of sequential events, particularly in ICU where the pHim provides a predictive information of the patient' status. The experimental evaluations of this new and innovative endoscopic fluorescence system confirms the accuracy of pH measurement using BCECF.

A technical review of flexible endoscopic multitasking platforms.

Science.gov (United States)

Yeung, Baldwin Po Man; Gourlay, Terence

2012-01-01

Further development of advanced therapeutic endoscopic techniques and natural orifice translumenal endoscopic surgery (NOTES) requires a powerful flexible endoscopic multitasking platform. Medline search was performed to identify literature relating to flexible endoscopic multitasking platform from year 2004-2011 using keywords: Flexible endoscopic multitasking platform, NOTES, Instrumentation, Endoscopic robotic surgery, and specific names of various endoscopic multitasking platforms. Key articles from articles references were reviewed. Flexible multitasking platforms can be classified as either mechanical or robotic. Purely mechanical systems include the dual channel endoscope (DCE) (Olympus), R-Scope (Olympus), the EndoSamurai (Olympus), the ANUBIScope (Karl-Storz), Incisionless Operating Platform (IOP) (USGI), and DDES system (Boston Scientific). Robotic systems include the MASTER system (Nanyang University, Singapore) and the Viacath (Hansen Medical). The DCE, the R-Scope, the EndoSamurai and the ANUBIScope have integrated visual function and instrument manipulation function. The IOP and DDES systems rely on the conventional flexible endoscope for visualization, and instrument manipulation is integrated through the use of a flexible, often lockable, multichannel access device. The advantage of the access device concept is that it allows optics and instrument dissociation. Due to the anatomical constrains of the pharynx, systems are designed to have a diameter of less than 20 mm. All systems are controlled by traction cable system actuated either by hand or by robotic machinery. In a flexible system, this method of actuation inevitably leads to significant hysteresis. This problem will be accentuated with a long endoscope such as that required in performing colonic procedures. Systems often require multiple operators. To date, the DCE, the R-Scope, the IOP, and the Viacath system have data published relating to their application in human. Alternative forms of

Limited endoscopic transsphenoidal approach for cavernous sinus biopsy: illustration of 3 cases and discussion.

Science.gov (United States)

Graillon, T; Fuentes, S; Metellus, P; Adetchessi, T; Gras, R; Dufour, H

2014-01-01

Advances in transsphenoidal surgery and endoscopic techniques have opened new perspectives for cavernous sinus (CS) approaches. The aim of this study was to assess the advantages and disadvantages of limited endoscopic transsphenoidal approach, as performed in pituitary adenoma surgery, for CS tumor biopsy illustrated with three clinical cases. The first case was a 46-year-old woman with a prior medical history of parotid adenocarcinoma successfully treated 10 years previously. The cavernous sinus tumor was revealed by right third and sixth nerve palsy and increased over the past three years. A tumor biopsy using a limited endoscopic transsphenoidal approach revealed an adenocarcinoma metastasis. Complementary radiosurgery was performed. The second case was a 36-year-old woman who consulted for diplopia with right sixth nerve palsy and amenorrhea with hyperprolactinemia. Dopamine agonist treatment was used to restore the patient's menstrual cycle. Cerebral magnetic resonance imaging (MRI) revealed a right sided CS tumor. CS biopsy, via a limited endoscopic transsphenoidal approach, confirmed a meningothelial grade 1 meningioma. Complementary radiosurgery was performed. The third case was a 63-year-old woman with progressive installation of left third nerve palsy and visual acuity loss, revealing a left cavernous sinus tumor invading the optic canal. Surgical biopsy was performed using an enlarged endoscopic transsphenoidal approach to the decompress optic nerve. Biopsy results revealed a meningothelial grade 1 meningioma. Complementary radiotherapy was performed. In these three cases, no complications were observed. Mean hospitalization duration was 4 days. Reported anatomical studies and clinical series have shown the feasibility of reaching the cavernous sinus using an endoscopic endonasal approach. Trans-foramen ovale CS percutaneous biopsy is an interesting procedure but only provides cell analysis results, and not tissue analysis. However, radiotherapy and

Development of stereo endoscope system with its innovative master interface for continuous surgical operation.

Science.gov (United States)

Kim, Myungjoon; Lee, Chiwon; Hong, Nhayoung; Kim, Yoon Jae; Kim, Sungwan

2017-06-24

Although robotic laparoscopic surgery has various benefits when compared with conventional open surgery and minimally invasive surgery, it also has issues to overcome and one of the issues is the discontinuous surgical flow that occurs whenever control is swapped between the endoscope system and the operating robot arm system. This can lead to problems such as collision between surgical instruments, injury to patients, and increased operation time. To achieve continuous surgical operation, a wireless controllable stereo endoscope system is proposed which enables the simultaneous control of the operating robot arm system and the endoscope system. The proposed system consists of two improved novel master interfaces (iNMIs), a four-degrees of freedom (4-DOFs) endoscope control system (ECS), and a simple three-dimensional (3D) endoscope. In order to simultaneously control the proposed system and patient side manipulators of da Vinci research kit (dVRK), the iNMIs are installed to the master tool manipulators of dVRK system. The 4-DOFs ECS consists of four servo motors and employs a two-parallel link structure to provide translational and fulcrum point motion to the simple 3D endoscope. The images acquired by the endoscope undergo stereo calibration and rectification to provide a clear 3D vision to the surgeon as available in clinically used da Vinci surgical robot systems. Tests designed to verify the accuracy, data transfer time, and power consumption of the iNMIs were performed. The workspace was calculated to estimate clinical applicability and a modified peg transfer task was conducted with three novice volunteers. The iNMIs operated for 317 min and moved in accordance with the surgeon's desire with a mean latency of 5 ms. The workspace was calculated to be 20378.3 cm 3 , which exceeds the reference workspace of 549.5 cm 3 . The novice volunteers were able to successfully execute the modified peg transfer task designed to evaluate the proposed system's overall

Characterization of Subsurface Defects in Ceramic Rods by Laser Scattering and Fractography

International Nuclear Information System (INIS)

Zhang, J. M.; Sun, J. G.; Andrews, M. J.; Ramesh, A.; Tretheway, J. S.; Longanbach, D. M.

2006-01-01

Silicon nitride ceramics are leading materials being evaluated for valve train components in diesel engine applications. The surface and subsurface defects and damage induced by surface machining can significantly affect component strength and lifetime. In this study, a nondestructive evaluation (NDE) technique based upon laser scattering has been utilized to analyze eight transversely ground silicon nitride cylindrical rods before fracture tests. The fracture origins (machining cracks or material-inherent flaws) identified by fractography after fracture testing were correlated with laser scattering images. The results indicate that laser scattering is able to identify possible fracture origin in the silicon nitride subsurface without the need for destructive fracture tests

Endoscopic biopsy of foramen of Monro and third ventricle lesions guided by frameless neuronavigation: usefulness and limitations.

Science.gov (United States)

Prat, Ricardo; Galeano, Inmaculada

2009-09-01

To describe our institution experience regarding the usefulness and limitations of frameless neuronavigation in the endoscopic biopsy of foramen of Monro and third ventricle lesions. We report our experience with 22 patients harbouring intraventricular lesions located in the region of the foramen of Monro or the third ventricle who underwent endoscopic biopsy guided by the neuronavigation system. Nine lesions were located on the posterior aspect of the third ventricle or at the pineal region, and thirteen lesions were located at the foramen of Monro or anterior third ventricle region. The endoscopes were introduced via an operating sheath, which had previously been inserted with a trocar under neuronavigational control. After approaching the foramen of Monro from the planned angle, surgery was continued under direct visualisation until the lesion was reached, if it was located on the third ventricle. In cases where the lesion was located at the foramen of Monro, an excellent view of the lesion was obtained and neuronavigation was used to determine the location of critical areas. Histological examination of biopsy specimens obtained endoscopically was diagnostic in all cases. Open surgery following endoscopic biopsy was only needed in 1 patient out of 22. In our experience, image-guided neuroendoscopy can improve the accuracy of the endoscopic approach, minimising brain trauma. It can be particularly helpful when performing a brain biopsy in the absence of clear intraventricular landmarks or in the event of adverse visual conditions such as intraventricular bleeding.

Usefulness of combined percutaneous-endoscopic rendezvous techniques after failed therapeutic endoscopic retrograde cholangiography in the era of endoscopic ultrasound guided rendezvous.

Science.gov (United States)

Yang, Min Jae; Kim, Jin Hong; Hwang, Jae Chul; Yoo, Byung Moo; Kim, Soon Sun; Lim, Sun Gyo; Won, Je Hwan

2017-12-01

The rendezvous approach is a salvage technique after failure of endoscopic retrograde cholangiography (ERC). In certain circumstances, percutaneous-endoscopic rendezvous (PE-RV) is preferred, and endoscopic ultrasound-guided rendezvous (EUS-RV) is difficult to perform. We aimed to evaluate PE-RV outcomes, describe the PE-RV techniques, and identify potential indications for PE-RV over EUS-RV.Retrospective analysis was conducted of a prospectively designed ERC database between January 2005 and December 2016 at a tertiary referral center including cases where PE-RV was used as a salvage procedure after ERC failure.During the study period, PE-RV was performed in 42 cases after failed therapeutic ERC; 15 had a surgically altered enteric anatomy. The technical success rate of PE-RV was 92.9% (39/42), with a therapeutic success rate of 88.1% (37/42). Potential indications for PE-RV over EUS-RV were identified in 23 cases, and either PE-RV or EUS-RV could have effectively been used in 19 cases. Endoscopic bile duct access was successfully achieved with PE-RV in 39 cases with accessible biliary orifice using one of PE-RV cannulation techniques (classic, n = 11; parallel, n = 19; and adjunctive maneuvers, n = 9).PE-RV uses a unique technology and has clinical indications that distinguish it from EUS-RV. Therefore, PE-RV can still be considered a useful salvage technique for the treatment of biliary obstruction after ERC failure.

Geoelectrical monitoring of simulated subsurface leakage to support high-hazard nuclear decommissioning at the Sellafield Site, UK

Energy Technology Data Exchange (ETDEWEB)

Kuras, Oliver, E-mail: oku@bgs.ac.uk [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Wilkinson, Paul B.; Meldrum, Philip I.; Oxby, Lucy S. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Uhlemann, Sebastian [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); ETH-Swiss Federal Institute of Technology, Institute of Geophysics, Sonneggstr. 5, 8092 Zurich (Switzerland); Chambers, Jonathan E. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Binley, Andrew [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Graham, James [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); Smith, Nicholas T. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); School of Earth, Atmospheric and Environmental Sciences, Williamson Building, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Atherton, Nick [Sellafield Ltd, Albion Square, Swingpump Lane, Whitehaven CA28 7NE (United Kingdom)

2016-10-01

A full-scale field experiment applying 4D (3D time-lapse) cross-borehole Electrical Resistivity Tomography (ERT) to the monitoring of simulated subsurface leakage was undertaken at a legacy nuclear waste silo at the Sellafield Site, UK. The experiment constituted the first application of geoelectrical monitoring in support of decommissioning work at a UK nuclear licensed site. Images of resistivity changes occurring since a baseline date prior to the simulated leaks revealed likely preferential pathways of silo liquor simulant flow in the vadose zone and upper groundwater system. Geophysical evidence was found to be compatible with historic contamination detected in permeable facies in sediment cores retrieved from the ERT boreholes. Results indicate that laterally discontinuous till units forming localized hydraulic barriers substantially affect flow patterns and contaminant transport in the shallow subsurface at Sellafield. We conclude that only geophysical imaging of the kind presented here has the potential to provide the detailed spatial and temporal information at the (sub-)meter scale needed to reduce the uncertainty in models of subsurface processes at nuclear sites. - Graphical abstract: 3D fractional resistivity change (resistivity change Δρ divided by baseline resistivity ρ{sub 0}) image showing results of Stage 1 silo liquor simulant injection. The black line delineates the preferential flow path; green cylinders show regions of historic contamination found in sediment cores from ERT boreholes. - Highlights: • 4D geoelectrical monitoring at Sellafield detected and tracked simulated silo leaks. • ERT revealed likely pathways of silo liquor simulant flow in the subsurface. • The method can reduce uncertainty in subsurface process models at nuclear sites. • Has been applied in this form at a UK nuclear licensed site for the first time • Study demonstrates value of 4D geophysics for nuclear decommissioning.

The Serpentinite Subsurface Microbiome

Science.gov (United States)

Schrenk, M. O.; Nelson, B. Y.; Brazelton, W. J.

2011-12-01

Microbial habitats hosted in ultramafic rocks constitute substantial, globally-distributed portions of the subsurface biosphere, occurring both on the continents and beneath the seafloor. The aqueous alteration of ultramafics, in a process known as serpentinization, creates energy rich, high pH conditions, with low concentrations of inorganic carbon which place fundamental constraints upon microbial metabolism and physiology. Despite their importance, very few studies have attempted to directly access and quantify microbial activities and distributions in the serpentinite subsurface microbiome. We have initiated microbiological studies of subsurface seeps and rocks at three separate continental sites of serpentinization in Newfoundland, Italy, and California and compared these results to previous analyses of the Lost City field, near the Mid-Atlantic Ridge. In all cases, microbial cell densities in seep fluids are extremely low, ranging from approximately 100,000 to less than 1,000 cells per milliliter. Culture-independent analyses of 16S rRNA genes revealed low-diversity microbial communities related to Gram-positive Firmicutes and hydrogen-oxidizing bacteria. Interestingly, unlike Lost City, there has been little evidence for significant archaeal populations in the continental subsurface to date. Culturing studies at the sites yielded numerous alkaliphilic isolates on nutrient-rich agar and putative iron-reducing bacteria in anaerobic incubations, many of which are related to known alkaliphilic and subsurface isolates. Finally, metagenomic data reinforce the culturing results, indicating the presence of genes associated with organotrophy, hydrogen oxidation, and iron reduction in seep fluid samples. Our data provide insight into the lifestyles of serpentinite subsurface microbial populations and targets for future quantitative exploration using both biochemical and geochemical approaches.

Microbial activity in the terrestrial subsurface

International Nuclear Information System (INIS)

Kaiser, J.P.; Bollag, J.M.

1990-01-01

Little is known about the layers under the earth's crust. Only in recent years have techniques for sampling the deeper subsurface been developed to permit investigation of the subsurface environment. Prevailing conditions in the subsurface habitat such as nutrient availability, soil composition, redox potential, permeability and a variety of other factors can influence the microflora that flourish in a given environment. Microbial diversity varies between geological formations, but in general sandy soils support growth better than soils rich in clay. Bacteria predominate in subsurface sediments, while eukaryotes constitute only 1-2% of the microorganisms. Recent investigations revealed that most uncontaminated subsurface soils support the growth of aerobic heteroorganotrophic bacteria, but obviously anaerobic microorganisms also exist in the deeper subsurface habitat. The microorganisms residing below the surface of the earth are capable of degrading both natural and xenobiotic contaminants and can thereby adapt to growth under polluted conditions. (author) 4 tabs, 77 refs

Use of Remote Sensing for Identification and Description of Subsurface Drainage System Condition

Directory of Open Access Journals (Sweden)

Lenka Tlapáková

2015-01-01

Full Text Available The paper presents basic facts and knowledge of special survey focused on detection and evaluation methods of subsurface drainage systems by means of remote sensing. It is aimed at the complex analysis of applied processes in spatial localization, classification or assessment of subsurface drainage systems’ actual condition by means of distance research methods. Data collection, their analysis and interpretation have been shown in seven experimental areas in the Czech Republic. Mainly it means determination of potential, application principles and limits of pracical use of different technologies and image data obtained by remote sensing in solving questions.

Balancing the shortcomings of microscope and endoscope: endoscope-assisted technique in microsurgical removal of recurrent epidermoid cysts in the posterior fossa.

Science.gov (United States)

Ebner, F H; Roser, F; Thaher, F; Schittenhelm, J; Tatagiba, M

2010-10-01

We report about endoscope-assisted surgery of epidermoid cysts in the posterior fossa focusing on the application of neuro-endoscopy and the clinical outcome in cases of recurrent epidermoid cysts. 25 consecutively operated patients with an epidermoid cyst in the posterior fossa were retrospectively analysed. Surgeries were performed both with an operating microscope (OPMI Pentero or NC 4, Zeiss Company, Oberkochen, Germany) and endoscopic equipment (4 mm rigid endoscopes with 30° and 70° optics; Karl Storz Company, Tuttlingen, Germany) under continuous intraoperative monitoring. Surgical reports and DVD-recordings were evaluated for identification of adhesion areas and surgical details. 7 (28%) of the 25 patients were recurrences of previously operated epidermoid cysts. Mean time to recurrence was 17 years (8-22 years). In 5 cases the endoscope was used as an adjunctive tool for inspection/endoscope-assisted removal of remnants. The effective time of use of the endoscope was limited to the end stage of the procedure, but was very effective. In a modern operative setting and with the necessary surgical experience recurrent epidermoid cysts may be removed with excellent clinical results. The combined use of microscope and endoscope offers relevant advantages in demanding anatomic situations. © Georg Thieme Verlag KG Stuttgart · New York.

Endoscopic Radiofrequency Ablation-Assisted Resection of Juvenile Nasopharyngeal Angiofibroma: Comparison with Traditional Endoscopic Technique.

Science.gov (United States)

McLaughlin, Eamon J; Cunningham, Michael J; Kazahaya, Ken; Hsing, Julianna; Kawai, Kosuke; Adil, Eelam A

2016-06-01

To evaluate the feasibility of radiofrequency surgical instrumentation for endoscopic resection of juvenile nasopharyngeal angiofibroma (JNA) and to test the hypothesis that endoscopic radiofrequency ablation-assisted (RFA) resection will have superior intraoperative and/or postoperative outcomes as compared with traditional endoscopic (TE) resection techniques. Case series with chart review. Two tertiary care pediatric hospitals. Twenty-nine pediatric patients who underwent endoscopic transnasal resection of JNA from January 2000 to December 2014. Twenty-nine patients underwent RFA (n = 13) or TE (n = 16) JNA resection over the 15-year study period. Mean patient age was not statistically different between the 2 groups (P = .41); neither was their University of Pittsburgh Medical Center classification stage (P = .79). All patients underwent preoperative embolization. Mean operative times were not statistically different (P = .29). Mean intraoperative blood loss and the need for a transfusion were also not statistically different (P = .27 and .47, respectively). Length of hospital stay was not statistically different (P = .46). Recurrence rates did not differ between groups (P = .99) over a mean follow-up period of 2.3 years. There were no significant differences between RFA and TE resection in intraoperative or postoperative outcome parameters. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Taking NOTES: translumenal flexible endoscopy and endoscopic surgery.

Science.gov (United States)

Willingham, Field F; Brugge, William R

2007-09-01

To review the current state of natural orifice surgery and examine the concerns, challenges, and opportunities presented by translumenal research. Translumenal endoscopic procedures have been the focus of extensive research. Researchers have reported natural orifice translumenal endoscopic surgery in a swine model in several areas involving the abdominal cavity. Diagnostic procedures have included endoscopic peritoneoscopy, liver biopsy, lymphadenectomy, and abdominal exploration. Several gynecologic procedures including tubal ligation, oophorectomy, and partial hysterectomy have been demonstrated using current commercial endoscopes. Gastrointestinal surgical procedures, including gastrojejunostomy, cholecystectomy, splenectomy, and distal pancreatectomy have been performed successfully via transgastric and/or transcolonic approaches. There have been no studies of natural orifice translumenal endoscopic surgery procedures published in humans. While fundamental questions about the emerging technology have not been scrutinized, limitations of the large animal model will pose a challenge to the development of large randomized trials. While natural orifice translumenal endoscopic surgery may represent a paradigm shift and may offer significant benefits to patients, rigorous testing of the techniques is lacking and current data have been drawn from case series.

Thematic survey of subsurface drainage systems in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Tlapáková, L.; Žaloudík, Jiří; Kolejka, Jaromír

2017-01-01

Roč. 13, č. 2 (2017), s. 55-65 ISSN 1744-5647 Institutional support: RVO:60077344 ; RVO:68145535 Keywords : subsurface drainage system * remote sensing * image interpretation * drainage recognition and mapping Subject RIV: DJ - Water Pollution ; Quality; DE - Earth Magnetism, Geodesy, Geography (UGN-S) OBOR OECD: Environmental sciences (social aspects to be 5.7); Physical geography (UGN-S) Impact factor: 2.174, year: 2016

Mucosa-associated lymphoid tissue lymphoma studied with FDG-PET. A comparison with CT and endoscopic findings

International Nuclear Information System (INIS)

Enomoto, Keisuke; Hamada, Kenichiro; Inohara, Hidenori; Higuchi, Ichiro; Kubo, Takeshi; Hatazawa, Jun; Tomita, Yasuhiko

2008-01-01

We investigated the accumulation of 2-deoxy-2-[ 18 F] fluoro-D-glucose positron emission tomography (FDG-PET) in patients with mucosa-associated lymphoid tissue (MALT) lymphoma patients as compared with computerized tomography (CT) and endoscopic imaging. FDG-PET was performed on 13 untreated patients with MALT lymphoma. CT scanning of the affected areas was performed in all the patients to compare with the FDG-PET images. In five patients with gastric MALT lymphoma, comparison was also made with the endoscopic findings. Of the 13 untreated MALT lymphoma patients, all 8 non-gastric MALT lymphoma patients exhibited abnormal accumulation of FDG. However, in the five gastric MALT lymphoma patients, no abnormal FDG accumulation was observed. Although lesions could be confirmed on CT images from the patients other than those with gastric MALT lymphoma, the mucosal lesions of gastric MALT lymphoma could be observed only by endoscopy. FDG-PET can be used to detect MALT lymphoma when it forms mass lesions, whereas it is difficult to detect non-massive MALT lymphoma of gastrointestinal origin. (author)

Endoscopic approach to the infratemporal fossa

Directory of Open Access Journals (Sweden)

Ahmed Youssef

2014-06-01

Conclusions: Endoscopic endonasal transpterygoid approach is considered one of the most useful surgical solutions to manage selected tumors that involve the infratemporal fossa. A good understanding of the endoscopic anatomy of infratemporal fossa allows safe and complete resection of lesions arising or extending to infratemporal fossa.

Radio-interferometric imaging of the subsurface emissions from the planet Mercury

Science.gov (United States)

Burns, J. O.; Zeilik, M.; Gisler, G. R.; Borovsky, J. E.; Baker, D. N.

1987-01-01

The distribution of total and polarized intensities from Mercury's subsurface layers have been mapped using VLA observations. The first detection of a hot pole along the Hermean equator is reported and modeled as black-body reradiation from preferential diurnal heating. These observations appear to rule out any internal sources of heat within Mercury. Polarized emission from the limb of the planet is also found, and is understood in terms of the dielectric properties of the Hermean surface.

[Endoscopic ultrasound guided rendezvous for biliary drainage].

Science.gov (United States)

Knudsen, Marie Høxbro; Vilmann, Peter; Hassan, Hazem; Karstensen, John Gésdal

2015-04-27

Endoscopic retrograde cholangiography (ERCP) is currently standard treatment for biliary drainage. Endoscopic ultrasound guided rendezvous (EUS-RV) is a novel method to overcome an unsuccessful biliary drainage procedure. Under endoscopic ultrasound guidance a guidewire is passed via a needle from the stomach or duodenum to the common bile duct and from there on to the duodenum enabling ERCP. With a relatively high rate of success EUS-RV should be considered as an alternative to biliary drainage and surgical intervention.

Elimination of high titre HIV from fibreoptic endoscopes.

Science.gov (United States)

Hanson, P J; Gor, D; Jeffries, D J; Collins, J V

1990-06-01

Concern about contamination of fibreoptic endoscopes with human immunodeficiency virus (HIV) has generated a variety of disruptive and possibly unnecessary infection control practices in endoscopy units. Current recommendations on the cleaning and disinfection of endoscopes have been formulated without applied experimental evidence of the effective removal of HIV from endoscopes. To study the kinetics of elimination of HIV from endoscope surfaces, we artificially contaminated the suction-biopsy channels of five Olympus GIF XQ20 endoscopes with high titre HIV in serum. The air and water channels of two instruments were similarly contaminated. Contamination was measured by irrigating channels with viral culture medium and collecting 3 ml at the distal end for antigen immunoassay. Endoscopes were then cleaned manually in neutral detergent according to the manufacturer's recommendations and disinfected in 2% alkaline glutaraldehyde (Cidex, Surgikos) for two, four, and ten minutes. Contamination with HIV antigens was measured before and after cleaning and after each period of disinfection. Initial contamination comprised 4.8 x 10(4) to 3.5 x 10(6) pg HIV antigen/ml. Cleaning in detergent achieved a reduction to 165 pg/ml (99.93%) on one endoscope and to undetectable levels (100%) on four. After two minutes in alkaline glutaraldehyde all samples were negative and remained negative after the longer disinfection times. Air and water channels, where contaminated, were tested after 10 minutes' disinfection and were negative. These findings underline the importance of cleaning in removing HIV from endoscope and indicate that the use of dedicated equipment and long disinfection times are unnecessary.

X-ray imaging of subsurface dynamics in high-Z materials at the Diamond Light Source

Science.gov (United States)

Eakins, D. E.; Chapman, D. J.

2014-12-01

In this paper, we describe a new approach enabling study of subsurface dynamics in high-Z materials using the unique combination of high-energy synchrotron X-rays, a hybrid bunch structure, and a new dynamic loading platform. We detail the design and operation of the purpose-built, portable small bore gas-gun, which was installed on the I12 high-energy beamline at the Diamond Light Source and used to drive compression waves into solid and porous metal targets. Using a hybrid bunch structure and broadband X-ray pulses of up to 300 keV, radiographic snapshots were captured during various dynamic deformation processes in cm-scale specimens, thereby contributing to a more complete understanding of the evolution of mesoscale damage. Importantly, we highlight strategies for overcoming the challenges associated with using high-energy X-rays, and suggest areas for improvement needed to advance dynamic imaging through large-scale samples of relevance to engineering scenarios. These preliminary measurements demonstrate the feasibility of probing highly transient phenomena using the presented methodology.

X-ray imaging of subsurface dynamics in high-Z materials at the Diamond Light Source

International Nuclear Information System (INIS)

Eakins, D. E.; Chapman, D. J.

2014-01-01

In this paper, we describe a new approach enabling study of subsurface dynamics in high-Z materials using the unique combination of high-energy synchrotron X-rays, a hybrid bunch structure, and a new dynamic loading platform. We detail the design and operation of the purpose-built, portable small bore gas-gun, which was installed on the I12 high-energy beamline at the Diamond Light Source and used to drive compression waves into solid and porous metal targets. Using a hybrid bunch structure and broadband X-ray pulses of up to 300 keV, radiographic snapshots were captured during various dynamic deformation processes in cm-scale specimens, thereby contributing to a more complete understanding of the evolution of mesoscale damage. Importantly, we highlight strategies for overcoming the challenges associated with using high-energy X-rays, and suggest areas for improvement needed to advance dynamic imaging through large-scale samples of relevance to engineering scenarios. These preliminary measurements demonstrate the feasibility of probing highly transient phenomena using the presented methodology

Significance of endoscopic screening and endoscopic resection for esophageal cancer in patients with hypopharyngeal cancer

International Nuclear Information System (INIS)

Morimoto, Masahiro; Nishiyama, Kinji; Nakamura, Satoaki

2010-01-01

The efficacy of endoscopic screening for esophageal cancer in patients with hypopharyngeal cancer remains controversial and its impact on prognosis has not been adequately discussed. We studied the use of endoscopic screening to detect esophageal cancer in hypopharyngeal cancer patients by analyzing the incidence, stage and prognosis. We included 64 patients with hypopharyngeal cancer who received radical radiotherapy at our institute. Chromoendoscopic esophageal examinations with Lugol dye solution were routinely performed at and after treatment for hypopharyngeal cancer. Twenty-eight esophageal cancers were detected in 28 (41%) patients (18 synchronous and 10 metachronous cancers). Of the 28 cancers, 23 were stage 0 or I cancer and 15 of these were treated with endoscopic resection. Local control was achieved in all of these 23 stage 0 or I cancers. The 5-year overall survival rates with esophageal cancer were 83% in stage 0, 47% in stage I and 0% in stage IIA-IVB. This study showed a strikingly high incidence of esophageal cancer in hypopharyngeal cancer patients. We suppose that the combination of early detection by chromoendoscopic examination and endoscopic resection for associated esophageal cancer in hypopharyngeal cancer patients improve prognosis and maintain quality of life. (author)

Limits of the endoscopic transnasal transtubercular approach.

Science.gov (United States)

Gellner, Verena; Tomazic, Peter V

2018-06-01

The endoscopic transnasal trans-sphenoidal transtubercular approach has become a standard alternative approach to neurosurgical transcranial routes for lesions of the anterior skull base in particular pathologies of the anterior tubercle, sphenoid plane, and midline lesions up to the interpeduncular cistern. For both the endoscopic and the transcranial approach indications must strictly be evaluated and tailored to the patients' morphology and condition. The purpose of this review was to evaluate the evidence in literature of the limitations of the endoscopic transtubercular approach. A PubMed/Medline search was conducted in January 2018 entering following keywords. Upon initial screening 7 papers were included in this review. There are several other papers describing the endoscopic transtubercular approach (ETTA). We tried to list the limitation factors according to the actual existing literature as cited. The main limiting factors are laterally extending lesions in relation to the optic canal and vascular encasement and/or unfavorable tumor tissue consistency. The ETTA is considered as a high level transnasal endoscopic extended skull base approach and requires excellent training, skills and experience.

Extended endoscopic endonasal surgery using three-dimensional endoscopy in the intra-operative MRI suite for supra-diaphragmatic ectopic pituitary adenoma.

Science.gov (United States)

Fuminari, Komatsu; Hideki, Atsumi; Manabu, Osakabe; Mitsunori, Matsumae

2015-01-01

We describe a supra-diaphragmatic ectopic pituitary adenoma that was safely removed using the extended endoscopic endonasal approach, and discuss the value of three-dimensional (3D) endoscopy and intra-operative magnetic resonance imaging (MRI) to this type of procedure. A 61-year-old-man with bitemporal hemianopsia was referred to our hospital, where MRI revealed an enhanced suprasellar tumor compressing the optic chiasma. The tumor extended on the planum sphenoidale and partially encased the right internal carotid artery. An endocrinological assessment indicated normal pituitary function. The extended endoscopic endonasal approach was taken using a 3D endoscope in the intraoperative MRI suite. The tumor was located above the diaphragma sellae and separated from the normal pituitary gland. The pathological findings indicated non-functioning pituitary adenoma and thus the tumor was diagnosed as a supra-diaphragmatic ectopic pituitary adenoma. Intra-operative MRI provided useful information to minimize dural opening and the supra-diaphragmatic ectopic pituitary adenoma was removed from the complex neurovascular structure via the extended endoscopic endonasal approach under 3D endoscopic guidance in the intra-operative suite. Safe and effective removal of a supra-diaphragmatic ectopic pituitary adenoma was accomplished via the extended endoscopic endonasal approach with visual information provided by 3D endoscopy and intra-operative MRI.

Laparoscopic-endoscopic rendezvous versus preoperative endoscopic sphincterotomy in people undergoing laparoscopic cholecystectomy for stones in the gallbladder and bile duct.

Science.gov (United States)

Vettoretto, Nereo; Arezzo, Alberto; Famiglietti, Federico; Cirocchi, Roberto; Moja, Lorenzo; Morino, Mario

2018-04-11

The management of gallbladder stones (lithiasis) concomitant with bile duct stones is controversial. The more frequent approach is a two-stage procedure, with endoscopic sphincterotomy and stone removal from the bile duct followed by laparoscopic cholecystectomy. The laparoscopic-endoscopic rendezvous combines the two techniques in a single-stage operation. To compare the benefits and harms of endoscopic sphincterotomy and stone removal followed by laparoscopic cholecystectomy (the single-stage rendezvous technique) versus preoperative endoscopic sphincterotomy followed by laparoscopic cholecystectomy (two stages) in people with gallbladder and common bile duct stones. We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, Science Citation Index Expanded Web of Science, and two trials registers (February 2017). We included randomised clinical trials that enrolled people with concomitant gallbladder and common bile duct stones, regardless of clinical status or diagnostic work-up, and compared laparoscopic-endoscopic rendezvous versus preoperative endoscopic sphincterotomy procedures in people undergoing laparoscopic cholecystectomy. We excluded other endoscopic or surgical methods of intraoperative clearance of the bile duct, e.g. non-aided intraoperative endoscopic retrograde cholangiopancreatography or laparoscopic choledocholithotomy (surgical incision of the common bile duct for removal of bile duct stones). We used standard methodological procedures recommended by Cochrane. We included five randomised clinical trials with 517 participants (257 underwent a laparoscopic-endoscopic rendezvous technique versus 260 underwent a sequential approach), which fulfilled our inclusion criteria and provided data for analysis. Trial participants were scheduled for laparoscopic cholecystectomy because of suspected cholecysto-choledocholithiasis. Male/female ratio was 0.7; age of men and women ranged from 21 years to 87

Endoscopic Palliation for Pancreatic Cancer

Directory of Open Access Journals (Sweden)

Mihir Bakhru

2011-04-01

Full Text Available Pancreatic cancer is devastating due to its poor prognosis. Patients require a multidisciplinary approach to guide available options, mostly palliative because of advanced disease at presentation. Palliation including relief of biliary obstruction, gastric outlet obstruction, and cancer-related pain has become the focus in patients whose cancer is determined to be unresectable. Endoscopic stenting for biliary obstruction is an option for drainage to avoid the complications including jaundice, pruritus, infection, liver dysfunction and eventually failure. Enteral stents can relieve gastric obstruction and allow patients to resume oral intake. Pain is difficult to treat in cancer patients and endoscopic procedures such as pancreatic stenting and celiac plexus neurolysis can provide relief. The objective of endoscopic palliation is to primarily address symptoms as well improve quality of life.

Cost-effectiveness of endoscopic ultrasonography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography in patients suspected of pancreaticobiliary disease

DEFF Research Database (Denmark)

Ainsworth, A P; Rafaelsen, S R; Wamberg, P A

2004-01-01

BACKGROUND: It is not known whether initial endoscopic ultrasonography (EUS) or magnetic resonance cholangiopancreatography (MRCP) is more cost effective than endoscopic retrograde cholangiopancreatography (ERCP). METHODS: A cost-effectiveness analysis of EUS, MRCP and ERCP was performed on 163...

Nitrogen patterns in subsurface waters of the Yzeron stream: effect of combined sewer overflows and subsurface-surface water mixing.

Science.gov (United States)

Aucour, A M; Bariac, T; Breil, P; Namour, P; Schmitt, L; Gnouma, R; Zuddas, P

2013-01-01

Urbanization subjects streams to increased nitrogen loads. Therefore studying nitrogen forms at the interface between urban stream and groundwater is important for water resource management. In this study we report results on water δ(18)O and nitrogen forms in subsurface waters of a stream (Yzeron, France). The sites studied were located upstream and downstream of combined sewer overflows (CSO) in a rural area and a periurban area, respectively. Water δ(18)O allowed us to follow the mixing of subsurface water with surface water. Dissolved organic nitrogen and organic carbon of fine sediment increased by 20-30% between rural and periurban subsurface waters in the cold season, under high flow. The highest nitrate levels were observed in rural subsurface waters in the cold season. The lowest nitrate levels were found in periurban subsurface waters in the warm season, under low flow. They corresponded to slow exchange of subsurface waters with channel water. Thus reduced exchange between surface and subsurface waters and organic-matter-rich input seemed to favor nitrate reduction in the downstream, periurban, subsurface waters impacted by CSO.

Endoscopic management of bile leaks after laparoscopic ...

African Journals Online (AJOL)

Endoscopic management of bile leaks after laparoscopic cholecystectomy. ... endoscopic management at a median of 12 days (range 2 - 104 days) after surgery. Presenting features included intra-abdominal collections with pain in 58 cases ...

A primer on endoscopic electronic medical records.

Science.gov (United States)

Atreja, Ashish; Rizk, Maged; Gurland, Brooke

2010-02-01

Endoscopic electronic medical record systems (EEMRs) are now increasingly utilized in many endoscopy centers. Modern EEMRs not only support endoscopy report generation, but often include features such as practice management tools, image and video clip management, inventory management, e-faxes to referring physicians, and database support to measure quality and patient outcomes. There are many existing software vendors offering EEMRs, and choosing a software vendor can be time consuming and confusing. The goal of this article is inform the readers about current functionalities available in modern EEMR and provide them with a framework necessary to find an EEMR that is best fit for their practice.

Endoscopic Ultrasonography in the Diagnosis of Gastric Subepithelial Lesions

Directory of Open Access Journals (Sweden)

Eun Jeong Gong

2016-09-01

Full Text Available Subepithelial lesions occasionally found in the stomach of patients undergoing endoscopy may be either benign lesions or tumors with malignant potential. They may also appear due to extrinsic compression. Discrimination of gastric subepithelial lesions begins with meticulous endoscopic examination for size, shape, color, mobility, consistency, and appearance of the overlying mucosa. Accurate diagnosis can be achieved with endoscopic ultrasonography, which provides useful information on the exact size, layer-of-origin, and characteristic morphologic features to support a definitive diagnosis. Endoscopic ultrasonography also aids in the prediction of malignant potential, especially in gastrointestinal stromal tumors. Features of subepithelial lesions identified on endoscopic ultrasonography can be used to determine whether further diagnostic procedures such as endoscopic resection, fine needle aspiration, or core biopsy are required. Endoscopic ultrasonography is a valuable tool for diagnosis and clinical decision making during follow-up of gastric subepithelial lesions.

Endoscopic Management of Tumor Bleeding from Inoperable Gastric Cancer

Science.gov (United States)

Kim, Young-Il

2015-01-01

Tumor bleeding is not a rare complication in patients with inoperable gastric cancer. Endoscopy has important roles in the diagnosis and primary treatment of tumor bleeding, similar to its roles in other non-variceal upper gastrointestinal bleeding cases. Although limited studies have been performed, endoscopic therapy has been highly successful in achieving initial hemostasis. One or a combination of endoscopic therapy modalities, such as injection therapy, mechanical therapy, or ablative therapy, can be used for hemostasis in patients with endoscopic stigmata of recent hemorrhage. However, rebleeding after successful hemostasis with endoscopic therapy frequently occurs. Endoscopic therapy may be a treatment option for successfully controlling this rebleeding. Transarterial embolization or palliative surgery should be considered when endoscopic therapy fails. For primary and secondary prevention of tumor bleeding, proton pump inhibitors can be prescribed, although their effectiveness to prevent bleeding remains to be investigated. PMID:25844339

Primary Signet Ring Cell Carcinoma of Rectum Diagnosed by Boring Biopsy in Combination with Endoscopic Mucosal Resection

Directory of Open Access Journals (Sweden)

Yoshito Hirata

2018-01-01

Full Text Available A 46-year-old man with severe back pain visited our hospital. Magnetic resonance imaging revealed extensive bone metastasis and rectal wall thickness. Colonoscopy revealed circumferential stenosis with edematous mucosa, suggesting colon cancer. However, histological findings of biopsy specimens revealed inflammatory cells but no malignant cells. The patient underwent endoscopic ultrasound, which demonstrated edematous wall thickness without destruction of the normal layer structure. After unsuccessful detection of neoplastic cells by boring biopsies, we performed endoscopic mucosal resection followed by boring biopsies that finally revealed signet ring cell carcinoma. Herein, we present a case and provide a review of the literature.

Platforms for hyperspectral imaging, in-situ optical and acoustical imaging in urbanized regions

Science.gov (United States)

Bostater, Charles R.; Oney, Taylor

2016-10-01

Hyperspectral measurements of the water surface of urban coastal waters are presented. Oblique bidirectional reflectance factor imagery was acquired made in a turbid coastal sub estuary of the Indian River Lagoon, Florida and along coastal surf zone waters of the nearby Atlantic Ocean. Imagery was also collected using a pushbroom hyperspectral imager mounted on a fixed platform with a calibrated circular mechatronic rotation stage. Oblique imagery of the shoreline and subsurface features clearly shows subsurface bottom features and rip current features within the surf zone water column. In-situ hyperspectral optical signatures were acquired from a vessel as a function of depth to determine the attenuation spectrum in Palm Bay. A unique stationary platform methodology to acquire subsurface acoustic images showing the presence of moving bottom boundary nephelometric layers passing through the acoustic fan beam. The acoustic fan beam imagery indicated the presence of oscillatory subsurface waves in the urbanized coastal estuary. Hyperspectral imaging using the fixed platform techniques are being used to collect hyperspectral bidirectional reflectance factor (BRF) measurements from locations at buildings and bridges in order to provide new opportunities to advance our scientific understanding of aquatic environments in urbanized regions.

The design of long wavelength planetary SAR sensor and its applications for monitoring shallow sub-surface of Moon and planets.

Science.gov (United States)

Kim, K.

2015-12-01

SAR observations over planetary surface have been conducted mainly in two ways. The first is the subsurface sounding, for example Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) and Shallow Surface Radar (SHARAD), using ground penetration capability of long wavelength electromagnetic waves. On the other hand, imaging SAR sensors using burst mode design have been employed to acquire surface observations in the presence of opaque atmospheres such as in the case of Venus and Titan. We propose a lightweight SAR imaging system with P/L band wavelength to cover the vertical observation gap of these planetary radar observation schemes. The sensor is for investigating prominent surface and near-subsurface geological structures and physical characteristics. Such measurements will support landers and rover missions as well as future manned missions. We evaluate required power consumption, and estimate mass and horizontal resolution, which can be as good as 3-7 meters. Initial specifications for P/L dual band SARs for the lunar case at 130 km orbital altitude were designed already based on a assumptions that sufficient size antenna (>3m width diameter or width about 3m and >10kg weight) can be equipped. Useful science measurements to be obtained include: (1) derivation of subsurface regolith depth; 2) Surface and shallow subsurface radar imaging, together with radar ranging techniques such as radargrammetry and inteferometry. The concepts in this study can be used as an important technical basis for the future solid plant/satellite missions and already proposed for the 2018 Korean Lunar mission.

Antibiotic prophylaxis for patients undergoing elective endoscopic ...

African Journals Online (AJOL)

Antibiotic prophylaxis for patients undergoing elective endoscopic retrograde cholangiopancreatography. M Brand, D Bisoz. Abstract. Background. Antibiotic prophylaxis for endoscopic retrograde cholangiopancreatography (ERCP) is controversial. We set out to assess the current antibiotic prescribing practice among ...

Endoscopic Instruments and Electrosurgical Unit for Colonoscopic Polypectomy

OpenAIRE

Park, Hong Jun

2016-01-01

Colorectal polypectomy is an effective method for prevention of colorectal cancer. Many endoscopic instruments have been used for colorectal polypectomy, such as snares, forceps, endoscopic clips, a Coagrasper, retrieval net, injector, and electrosurgery generator unit (ESU). Understanding the characteristics of endoscopic instruments and their proper use according to morphology and size of the colorectal polyp will enable endoscopists to perform effective polypectomy. I reviewed the characte...

Measurement of distances between anatomical structures using a translating stage with mounted endoscope

Science.gov (United States)

Kahrs, Lueder A.; Blachon, Gregoire S.; Balachandran, Ramya; Fitzpatrick, J. Michael; Labadie, Robert F.

2012-02-01

During endoscopic procedures it is often desirable to determine the distance between anatomical features. One such clinical application is percutaneous cochlear implantation (PCI), which is a minimally invasive approach to the cochlea via a single, straight drill path and can be achieved accurately using bone-implanted markers and customized microstereotactic frame. During clinical studies to validate PCI, traditional open-field cochlear implant surgery was performed and prior to completion of the surgery, a customized microstereotactic frame designed to achieve the desired PCI trajectory was attached to the bone-implanted markers. To determine whether this trajectory would have safely achieved the target, a sham drill bit is passed through the frame to ensure that the drill bit would reach the cochlea without damaging vital structures. Because of limited access within the facial recess, the distances from the bit to anatomical features could not be measured with calipers. We hypothesized that an endoscope mounted on a sliding stage that translates only along the trajectory, would provide sufficient triangulation to accurately measure these distances. In this paper, the design, fabrication, and testing of such a system is described. The endoscope is mounted so that its optical axis is approximately aligned with the trajectory. Several images are acquired as the stage is moved, and threedimensional reconstruction of selected points allows determination of distances. This concept also has applicability in a large variety of rigid endoscopic interventions including bronchoscopy, laparoscopy, and sinus endoscopy.

Medical imaging systems

Science.gov (United States)

Frangioni, John V

2013-06-25

A medical imaging system provides simultaneous rendering of visible light and diagnostic or functional images. The system may be portable, and may include adapters for connecting various light sources and cameras in open surgical environments or laparascopic or endoscopic environments. A user interface provides control over the functionality of the integrated imaging system. In one embodiment, the system provides a tool for surgical pathology.

Depth-resolved imaging of colon tumor using optical coherence tomography and fluorescence laminar optical tomography (Conference Presentation)