Conjugation of fiber-coupled wide-band light sources and acousto-optical spectral elements

NASA Astrophysics Data System (ADS)

Machikhin, Alexander; Batshev, Vladislav; Polschikova, Olga; Khokhlov, Demid; Pozhar, Vitold; Gorevoy, Alexey

2017-12-01

Endoscopic instrumentation is widely used for diagnostics and surgery. The imaging systems, which provide the hyperspectral information of the tissues accessible by endoscopes, are particularly interesting and promising for in vivo photoluminescence diagnostics and therapy of tumour and inflammatory diseases. To add the spectral imaging feature to standard video endoscopes, we propose to implement acousto-optical (AO) filtration of wide-band illumination of incandescent-lamp-based light sources. To collect maximum light and direct it to the fiber-optic light guide inside the endoscopic probe, we have developed and tested the optical system for coupling the light source, the acousto-optical tunable filter (AOTF) and the light guide. The system is compact and compatible with the standard endoscopic components.

Passively Driven Probe Based on Miniaturized Propeller for Intravascular Optical Coherence Tomography.

PubMed

Lu, Yu; Li, Zhongliang; Nan, Nan; Bu, Yang; Liu, Xuebo; Xu, Xiangdong; Wang, Xuan; Sasaki, Osami; Wang, Xiangzhao

2018-03-26

Optical coherent tomography (OCT) has enabled clinical applications ranging from ophthalmology to cardiology that revolutionized in vivo medical diagnostics in the last few decades, and a variety of endoscopic probes have been developed in order to meet the needs of various endoscopic OCT imaging. We propose a passive driven intravascular optical coherent tomography (IV-OCT) probe in this paper. Instead of using any electrically driven scanning device, the probe makes use of the kinetic energy of the fluid that flushes away the blood during the intravascular optical coherence tomography imaging. The probe converts it into the rotational kinetic energy of the propeller, and the rotation of the rectangular prism mounted on the propeller shaft enables the scanning of the beam. The probe is low cost, and enables unobstructed stable circumferential scanning over 360 deg. The experimental results show that the probe scanning speed can exceed 100 rotations per second (rps). Spectral-domain OCT imaging of a phantom and porcine cardiac artery are demonstrated with axial resolution of 13.6 μm, lateral resolution of 22 μm, and sensitivity of 101.7 dB. We present technically the passively driven IV-OCT probe in full detail and discuss how to optimize the probe in further.

MEMS scanning micromirror for optical coherence tomography.

PubMed

Strathman, Matthew; Liu, Yunbo; Keeler, Ethan G; Song, Mingli; Baran, Utku; Xi, Jiefeng; Sun, Ming-Ting; Wang, Ruikang; Li, Xingde; Lin, Lih Y

2015-01-01

This paper describes an endoscopic-inspired imaging system employing a micro-electromechanical system (MEMS) micromirror scanner to achieve beam scanning for optical coherence tomography (OCT) imaging. Miniaturization of a scanning mirror using MEMS technology can allow a fully functional imaging probe to be contained in a package sufficiently small for utilization in a working channel of a standard gastroesophageal endoscope. This work employs advanced image processing techniques to enhance the images acquired using the MEMS scanner to correct non-idealities in mirror performance. The experimental results demonstrate the effectiveness of the proposed technique.

MEMS scanning micromirror for optical coherence tomography

PubMed Central

Strathman, Matthew; Liu, Yunbo; Keeler, Ethan G.; Song, Mingli; Baran, Utku; Xi, Jiefeng; Sun, Ming-Ting; Wang, Ruikang; Li, Xingde; Lin, Lih Y.

2014-01-01

This paper describes an endoscopic-inspired imaging system employing a micro-electromechanical system (MEMS) micromirror scanner to achieve beam scanning for optical coherence tomography (OCT) imaging. Miniaturization of a scanning mirror using MEMS technology can allow a fully functional imaging probe to be contained in a package sufficiently small for utilization in a working channel of a standard gastroesophageal endoscope. This work employs advanced image processing techniques to enhance the images acquired using the MEMS scanner to correct non-idealities in mirror performance. The experimental results demonstrate the effectiveness of the proposed technique. PMID:25657887

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

NASA Astrophysics Data System (ADS)

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.

Doppler imaging using spectrally-encoded endoscopy

PubMed Central

Yelin, Dvir; Bouma, B. E.; Rosowsky, J. J.; Tearney, G. J.

2009-01-01

The capability to image tissue motion such as blood flow through an endoscope could have many applications in medicine. Spectrally encoded endoscopy (SEE) is a recently introduced technique that utilizes a single optical fiber and miniature diffractive optics to obtain endoscopic images through small diameter probes. Using spectral-domain interferometry, SEE is furthermore capable of three-dimensional volume imaging at video rates. Here we show that by measuring relative spectral phases, this technology can additionally measure Doppler shifts. Doppler SEE is demonstrated in flowing Intralipid phantoms and vibrating middle ear ossicles. PMID:18795020

Dual-modality endoscopic probe for tissue surface shape reconstruction and hyperspectral imaging enabled by deep neural networks.

PubMed

Lin, Jianyu; Clancy, Neil T; Qi, Ji; Hu, Yang; Tatla, Taran; Stoyanov, Danail; Maier-Hein, Lena; Elson, Daniel S

2018-06-15

Surgical guidance and decision making could be improved with accurate and real-time measurement of intra-operative data including shape and spectral information of the tissue surface. In this work, a dual-modality endoscopic system has been proposed to enable tissue surface shape reconstruction and hyperspectral imaging (HSI). This system centers around a probe comprised of an incoherent fiber bundle, whose fiber arrangement is different at the two ends, and miniature imaging optics. For 3D reconstruction with structured light (SL), a light pattern formed of randomly distributed spots with different colors is projected onto the tissue surface, creating artificial texture. Pattern decoding with a Convolutional Neural Network (CNN) model and a customized feature descriptor enables real-time 3D surface reconstruction at approximately 12 frames per second (FPS). In HSI mode, spatially sparse hyperspectral signals from the tissue surface can be captured with a slit hyperspectral imager in a single snapshot. A CNN based super-resolution model, namely "super-spectral-resolution" network (SSRNet), has also been developed to estimate pixel-level dense hypercubes from the endoscope cameras standard RGB images and the sparse hyperspectral signals, at approximately 2 FPS. The probe, with a 2.1 mm diameter, enables the system to be used with endoscope working channels. Furthermore, since data acquisition in both modes can be accomplished in one snapshot, operation of this system in clinical applications is minimally affected by tissue surface movement and deformation. The whole apparatus has been validated on phantoms and tissue (ex vivo and in vivo), while initial measurements on patients during laryngeal surgery show its potential in real-world clinical applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Recent advances in targeted endoscopic imaging: Early detection of gastrointestinal neoplasms

PubMed Central

Kwon, Yong-Soo; Cho, Young-Seok; Yoon, Tae-Jong; Kim, Ho-Shik; Choi, Myung-Gyu

2012-01-01

Molecular imaging has emerged as a new discipline in gastrointestinal endoscopy. This technology encompasses modalities that can visualize disease-specific morphological or functional tissue changes based on the molecular signature of individual cells. Molecular imaging has several advantages including minimal damage to tissues, repetitive visualization, and utility for conducting quantitative analyses. Advancements in basic science coupled with endoscopy have made early detection of gastrointestinal cancer possible. Molecular imaging during gastrointestinal endoscopy requires the development of safe biomarkers and exogenous probes to detect molecular changes in cells with high specificity anda high signal-to-background ratio. Additionally, a high-resolution endoscope with an accurate wide-field viewing capability must be developed. Targeted endoscopic imaging is expected to improve early diagnosis and individual therapy of gastrointestinal cancer. PMID:22442742

Integrated Raman spectroscopy and trimodal wide-field imaging techniques for real-time in vivo tissue Raman measurements at endoscopy.

PubMed

Huang, Zhiwei; Teh, Seng Khoon; Zheng, Wei; Mo, Jianhua; Lin, Kan; Shao, Xiaozhuo; Ho, Khek Yu; Teh, Ming; Yeoh, Khay Guan

2009-03-15

We report an integrated Raman spectroscopy and trimodal (white-light reflectance, autofluorescence, and narrow-band) imaging techniques for real-time in vivo tissue Raman measurements at endoscopy. A special 1.8 mm endoscopic Raman probe with filtering modules is developed, permitting effective elimination of interference of fluorescence background and silica Raman in fibers while maximizing tissue Raman collections. We demonstrate that high-quality in vivo Raman spectra of upper gastrointestinal tract can be acquired within 1 s or subseconds under the guidance of wide-field endoscopic imaging modalities, greatly facilitating the adoption of Raman spectroscopy into clinical research and practice during routine endoscopic inspections.

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

NASA Astrophysics Data System (ADS)

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.

Intravital imaging of mouse colonic adenoma using MMP-based molecular probes with multi-channel fluorescence endoscopy.

PubMed

Oh, Gyungseok; Yoo, Su Woong; Jung, Yebin; Ryu, Yeon-Mi; Park, Youngrong; Kim, Sang-Yeob; Kim, Ki Hean; Kim, Sungjee; Myung, Seung-Jae; Chung, Euiheon

2014-05-01

Intravital imaging has provided molecular, cellular and anatomical insight into the study of tumor. Early detection and treatment of gastrointestinal (GI) diseases can be enhanced with specific molecular markers and endoscopic imaging modalities. We present a wide-field multi-channel fluorescence endoscope to screen GI tract for colon cancer using multiple molecular probes targeting matrix metalloproteinases (MMP) conjugated with quantum dots (QD) in AOM/DSS mouse model. MMP9 and MMP14 antibody (Ab)-QD conjugates demonstrate specific binding to colonic adenoma. The average target-to-background (T/B) ratios are 2.10 ± 0.28 and 1.78 ± 0.18 for MMP14 Ab-QD and MMP9 Ab-QD, respectively. The overlap between the two molecular probes is 67.7 ± 8.4%. The presence of false negative indicates that even more number of targeting could increase the sensitivity of overall detection given heterogeneous molecular expression in tumors. Our approach indicates potential for the screening of small or flat lesions that are precancerous.

Common path endoscopic probes for optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Singh, Kanwarpal; Gardecki, Joseph A.; Tearney, Guillermo J.

2017-02-01

Background: Dispersion imbalance and polarization mismatch between the reference and sample arm signals can lead to image quality degradation in optical coherence tomography (OCT). One approach to reduce these image artifacts is to employ a common-path geometry in fiber-based probes. In this work, we report an 800 um diameter all-fiber common-path monolithic probe for coronary artery imaging where the reference signal is generated using an inline fiber partial reflector. Methods: Our common-path probe was designed for swept-source based Fourier domain OCT at 1310 nm wavelength. A face of a coreless fiber was coated with gold and spliced to a standard SMF-28 single mode fiber creating an inline partial reflector, which acted as a reference surface. The other face of the coreless fiber was shaped into a ball lens for focusing. The optical elements were assembled within a 560 µm diameter drive shaft, which was attached to a rotary junction. The drive shaft was placed inside a transparent sheath having an outer diameter of 800 µm. Results: With a source input power of 30mW, the inline common-path probe achieved a sensitivity of 104 dB. Images of human finger skin showed the characteristic layers of skin as well as features such as sweat ducts. Images of coronary arteries ex vivo obtained with this probe enabled visualization of the characteristic architectural morphology of the normal artery wall and known features of atherosclerotic plaque. Conclusion: In this work, we have demonstrated a common path OCT probe for cardiovascular imaging. The probe is easy to fabricate, will reduce system complexity and overall cost. We believe that this design will be helpful in endoscopic applications that require high resolution and a compact form factor.

Endoscopic optical coherence tomography: technologies and clinical applications [Invited

PubMed Central

Gora, Michalina J.; Suter, Melissa J.; Tearney, Guillermo J.; Li, Xingde

2017-01-01

In this paper, we review the current state of technology development and clinical applications of endoscopic optical coherence tomography (OCT). Key design and engineering considerations are discussed for most OCT endoscopes, including side-viewing and forward-viewing probes, along with different scanning mechanisms (proximal-scanning versus distal-scanning). Multi-modal endoscopes that integrate OCT with other imaging modalities are also discussed. The review of clinical applications of endoscopic OCT focuses heavily on diagnosis of diseases and guidance of interventions. Representative applications in several organ systems are presented, such as in the cardiovascular, digestive, respiratory, and reproductive systems. A brief outlook of the field of endoscopic OCT is also discussed. PMID:28663882

A Clinical Wide-Field Fluorescence Endoscopic Device for Molecular Imaging Demonstrating Cathepsin Protease Activity in Colon Cancer.

PubMed

Sensarn, Steven; Zavaleta, Cristina L; Segal, Ehud; Rogalla, Stephan; Lee, Wansik; Gambhir, Sanjiv S; Bogyo, Matthew; Contag, Christopher H

2016-12-01

Early and effective detection of cancers of the gastrointestinal tract will require novel molecular probes and advances in instrumentation that can reveal functional changes in dysplastic and malignant tissues. Here, we describe adaptation of a wide-field clinical fiberscope to perform wide-field fluorescence imaging while preserving its white-light capability for the purpose of providing wide-field fluorescence imaging capability to point-of-care microscopes. We developed and used a fluorescent fiberscope to detect signals from a quenched probe, BMV109, that becomes fluorescent when cleaved by, and covalently bound to, active cathepsin proteases. Cathepsins are expressed in inflammation- and tumor-associated macrophages as well as directly from tumor cells and are a promising target for cancer imaging. The fiberscope has a 1-mm outer diameter enabling validation via endoscopic exams in mice, and therefore we evaluated topically applied BMV109 for the ability to detect colon polyps in an azoxymethane-induced colon tumor model in mice. This wide-field endoscopic imaging device revealed consistent and clear fluorescence signals from BMV109 that specifically localized to the polypoid regions as opposed to the normal adjacent colon tissue (p < 0.004) in the murine colon carcinoma model. The sensitivity of detection of BMV109 with the fluorescence fiberscope suggested utility of these tools for early detection at hard-to-reach sites. The fiberscope was designed to be used in conjunction with miniature, endoscope-compatible fluorescence microscopes for dual wide-field and microscopic cancer detection.

Catheter-based flexible microcoil RF detectors for internal magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Ahmad, M. M.; Syms, R. R. A.; Young, I. R.; Mathew, B.; Casperz, W.; Taylor-Robinson, S. D.; Wadsworth, C. A.; Gedroyc, W. M. W.

2009-07-01

Flexible catheter probes for magnetic resonance imaging (MRI) of the bile duct are demonstrated. The probes consist of a cytology brush modified to accept a resonant RF detector based on a spiral microcoil and hybrid integrated capacitors, and are designed for insertion into the duct via a non-magnetic endoscope during endoscopic retrograde cholangiopancreatography (ERCP). The coil must be narrow enough (<3 mm) to pass through the biopsy channel of the endoscope and sufficiently flexible to turn through 90° to enter the duct. Coils are fabricated as multi-turn electroplated conductors on a flexible base, and two designs formed on SU-8 and polyimide substrates are compared. It is shown that careful control of thermal load is used to obtain useable mechanical properties from SU-8, and that polyimide/SU-8 composites offer improved mechanical reliability. Good electrical performance is demonstrated and sub-millimetre resolution is obtained in 1H MRI experiments at 1.5 T magnetic field strength using test phantoms and in vitro liver tissue.

Spectral-domain optical coherence tomography for endoscopic imaging

NASA Astrophysics Data System (ADS)

Chen, Xiaodong; Li, Qiao; Li, Wanhui; Wang, Yi; Yu, Daoyin

2007-02-01

Optical coherence tomography (OCT) is an emerging cross-sectional imaging technology. It uses broadband light sources to achieve axial image resolutions on the few micron scale. OCT is widely applied to medical imaging, it can get cross-sectional image of bio-tissue (transparent and turbid) with non-invasion and non-touch. In this paper, the principle of OCT is presented and the crucial parameters of the system are discussed in theory. With analysis of different methods and medical endoscopic system's feature, a design which combines the spectral domain OCT (SDOCT) technique and endoscopy is put forward. SDOCT provides direct access to the spectrum of the optical signal. It is shown to provide higher imaging speed when compared to time domain OCT. At the meantime, a novel OCT probe which uses advanced micromotor to drive reflecting prism is designed according to alimentary tract endoscopic feature. A simple optical coherence tomography system has been developed based on a fiber-based Michelson interferometer and spectrometer. An experiment which uses motor to drive prism to realize rotating imaging is done. Images obtained with this spectral interferometer are presented. The results verify the feasibility of endoscopic optical coherence tomography system with rotating scan.

A Clinical Wide-Field Fluorescence Endoscopic Device for Molecular Imaging Demonstrating Cathepsin Protease Activity in Colon Cancer

PubMed Central

Sensarn, Steven; Zavaleta, Cristina L.; Segal, Ehud; Rogalla, Stephan; Lee, Wansik; Gambhir, Sanjiv S.; Bogyo, Matthew; Contag, Christopher H.

2017-01-01

Purpose Early and effective detection of cancers of the gastrointestinal tract will require novel molecular probes and advances in instrumentation that can reveal functional changes in dysplastic and malignant tissues. Here, we describe adaptation of a wide-field clinical fiberscope to perform wide-field fluorescence imaging while preserving its white-light capability for the purpose of providing wide-field fluorescence imaging capability to point-of-care microscopes. Procedures We developed and used a fluorescent fiberscope to detect signals from a quenched probe, BMV109, that becomes fluorescent when cleaved by, and covalently bound to, active cathepsin proteases. Cathepsins are expressed in inflammation- and tumor-associated macrophages as well as directly from tumor cells and are a promising target for cancer imaging. The fiberscope has a 1-mm outer diameter enabling validation via endoscopic exams in mice, and therefore we evaluated topically applied BMV109 for the ability to detect colon polyps in an azoxymethane-induced colon tumor model in mice. Results This wide-field endoscopic imaging device revealed consistent and clear fluorescence signals from BMV109 that specifically localized to the polypoid regions as opposed to the normal adjacent colon tissue (p < 0.004) in the murine colon carcinoma model. Conclusions The sensitivity of detection of BMV109 with the fluorescence fiberscope suggested utility of these tools for early detection at hard-to-reach sites. The fiberscope was designed to be used in conjunction with miniature, endoscope-compatible fluorescence microscopes for dual wide-field and microscopic cancer detection. PMID:27154508

An automatic detection method for the boiler pipe header based on real-time image acquisition

NASA Astrophysics Data System (ADS)

Long, Yi; Liu, YunLong; Qin, Yongliang; Yang, XiangWei; Li, DengKe; Shen, DingJie

2017-06-01

Generally, an endoscope is used to test the inner part of the thermal power plants boiler pipe header. However, since the endoscope hose manual operation, the length and angle of the inserted probe cannot be controlled. Additionally, it has a big blind spot observation subject to the length of the endoscope wire. To solve these problems, an automatic detection method for the boiler pipe header based on real-time image acquisition and simulation comparison techniques was proposed. The magnetic crawler with permanent magnet wheel could carry the real-time image acquisition device to complete the crawling work and collect the real-time scene image. According to the obtained location by using the positioning auxiliary device, the position of the real-time detection image in a virtual 3-D model was calibrated. Through comparing of the real-time detection images and the computer simulation images, the defects or foreign matter fall into could be accurately positioning, so as to repair and clean up conveniently.

Rapid and sensitive detection of early esophageal squamous cell carcinoma with fluorescence probe targeting dipeptidylpeptidase IV

PubMed Central

Onoyama, Haruna; Kamiya, Mako; Kuriki, Yugo; Komatsu, Toru; Abe, Hiroyuki; Tsuji, Yosuke; Yagi, Koichi; Yamagata, Yukinori; Aikou, Susumu; Nishida, Masato; Mori, Kazuhiko; Yamashita, Hiroharu; Fujishiro, Mitsuhiro; Nomura, Sachiyo; Shimizu, Nobuyuki; Fukayama, Masashi; Koike, Kazuhiko; Urano, Yasuteru; Seto, Yasuyuki

2016-01-01

Early detection of esophageal squamous cell carcinoma (ESCC) is an important prognosticator, but is difficult to achieve by conventional endoscopy. Conventional lugol chromoendoscopy and equipment-based image-enhanced endoscopy, such as narrow-band imaging (NBI), have various practical limitations. Since fluorescence-based visualization is considered a promising approach, we aimed to develop an activatable fluorescence probe to visualize ESCCs. First, based on the fact that various aminopeptidase activities are elevated in cancer, we screened freshly resected specimens from patients with a series of aminopeptidase-activatable fluorescence probes. The results indicated that dipeptidylpeptidase IV (DPP-IV) is specifically activated in ESCCs, and would be a suitable molecular target for detection of esophageal cancer. Therefore, we designed, synthesized and characterized a series of DPP-IV-activatable fluorescence probes. When the selected probe was topically sprayed onto endoscopic submucosal dissection (ESD) or surgical specimens, tumors were visualized within 5 min, and when the probe was sprayed on biopsy samples, the sensitivity, specificity and accuracy reached 96.9%, 85.7% and 90.5%. We believe that DPP-IV-targeted activatable fluorescence probes are practically translatable as convenient tools for clinical application to enable rapid and accurate diagnosis of early esophageal cancer during endoscopic or surgical procedures. PMID:27245876

Imaging pancreatobiliary ductal system with optical coherence tomography: A review

PubMed Central

Mahmud, Mohammad S; May, Gray R; Kamal, Mohammad M; Khwaja, Ahmed S; Sun, Carry; Vitkin, Alex; Yang, Victor XD

2013-01-01

An accurate, noninvasive and cost-effective method of in situ tissue evaluation during endoscopy would be highly advantageous for the detection of dysplasia or early cancer and for identifying different disease stages. Optical coherence tomography (OCT) is a noninvasive, high-resolution (1-10 μm) emerging optical imaging method with potential for identifying microscopic subsurface features in the pancreatic and biliary ductal system. Tissue microstructure of pancreaticobiliary ductal system has been successfully imaged by inserting an OCT probe through a standard endoscope operative channel. High-resolution OCT images and the technique’s endoscopic compatibility have allowed for the microstructural diagnostic of the pancreatobiliary diseases. In this review, we discussed currently available pancreaticobiliary ductal imaging systems to assess the pancreatobiliary tissue microstructure and to evaluate varieties of pancreaticobiliary disorders and diseases. Results show that OCT can improve the quality of images of pancreatobiliary system during endoscopic retrograde cholangiopancheatography procedure, which may be important in distinguishing between the neoplastic and non-neoplastic lesions. PMID:24255746

Spatial-scanning hyperspectral imaging probe for bio-imaging applications

NASA Astrophysics Data System (ADS)

Lim, Hoong-Ta; Murukeshan, Vadakke Matham

2016-03-01

The three common methods to perform hyperspectral imaging are the spatial-scanning, spectral-scanning, and snapshot methods. However, only the spectral-scanning and snapshot methods have been configured to a hyperspectral imaging probe as of today. This paper presents a spatial-scanning (pushbroom) hyperspectral imaging probe, which is realized by integrating a pushbroom hyperspectral imager with an imaging probe. The proposed hyperspectral imaging probe can also function as an endoscopic probe by integrating a custom fabricated image fiber bundle unit. The imaging probe is configured by incorporating a gradient-index lens at the end face of an image fiber bundle that consists of about 50 000 individual fiberlets. The necessary simulations, methodology, and detailed instrumentation aspects that are carried out are explained followed by assessing the developed probe's performance. Resolution test targets such as United States Air Force chart as well as bio-samples such as chicken breast tissue with blood clot are used as test samples for resolution analysis and for performance validation. This system is built on a pushbroom hyperspectral imaging system with a video camera and has the advantage of acquiring information from a large number of spectral bands with selectable region of interest. The advantages of this spatial-scanning hyperspectral imaging probe can be extended to test samples or tissues residing in regions that are difficult to access with potential diagnostic bio-imaging applications.

A 2.5-mm diameter probe for photoacoustic and ultrasonic endoscopy

PubMed Central

Yang, Joon-Mo; Chen, Ruimin; Favazza, Christopher; Yao, Junjie; Li, Chiye; Hu, Zhilin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

2012-01-01

We have created a 2.5-mm outer diameter integrated photo-acoustic and ultrasonic mini-probe which can be inserted into a standard video endoscope’s instrument channel. A small-diameter focused ultrasonic transducer made of PMN-PT provides adequate signal sensitivity, and enables miniaturization of the probe. Additionally, this new endoscopic probe utilizes the same scanning mirror and micromotor-based built-in actuator described in our previous reports; however, the length of the rigid distal section of the new probe has been further reduced to ~35 mm. This paper describes the technical details of the mini-probe and presents experimental results that both quantify the imaging performance and demonstrate its in vivo imaging capability, which suggests that it could work as a mini-probe for certain clinical applications. PMID:23188360

Endoscopic Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Zhou, Chao; Fujimoto, James G.; Tsai, Tsung-Han; Mashimo, Hiroshi

New gastrointestinal (GI) cancers are expected to affect more than 290,200 new patients and will cause more than 144,570 deaths in the United States in 2013 [1]. When detected and treated early, the 5-year survival rate for colorectal cancer increases by a factor of 1.4 [1]. For esophageal cancer, the rate increases by a factor of 2 [1]. The majority of GI cancers begin as small lesions that are difficult to identify with conventional endoscopy. With resolutions approaching that of histopathology, optical coherence tomography (OCT) is well suited for detecting the changes in tissue microstructure associated with early GI cancers. Since the lesions are not endoscopically apparent, however, it is necessary to survey a relatively large area of the GI tract. Tissue motion is another limiting factor in the GI tract; therefore, in vivo imaging must be performed at extremely high speeds. OCT imaging can be performed using fiber optics and miniaturized lens systems, enabling endoscopic OCT inside the human body in conjunction with conventional video endoscopy. An OCT probe can be inserted through the working channel of a standard endoscope, thus enabling depth-resolved imaging of tissue microstructure in the GI tract with micron-scale resolution simultaneously with the endoscopic view (Fig. 68.1).

Image-guided intervention in the human bile duct using scanning fiber endoscope system

NASA Astrophysics Data System (ADS)

Seibel, Eric J.; Jo, Javier A.; Melville, C. David; Johnston, Richard S.; Naumann, Christopher R.; Saunders, Michael D.

2012-01-01

Bile duct cancers are increasing in frequency while being difficult to diagnose. Currently available endoscopic imaging devices used in the biliary tree are low resolution with poor image quality, leading to inadequate evaluation of indeterminate biliary strictures. However, a new ultrathin and flexible cholangioscope system has been successfully demonstrated in a human subject. This mini-cholangioscope system uses a scanning fiber endoscope (SFE) as a forward-imaging guidewire, dimensions of 1.2-mm diameter and 3-m length. Full color video (500-line resolution at 30Hz) is the standard SFE imaging mode using spiral scanning of red, green, and blue laser light at low power. Image-guided operation of the biopsy forceps was demonstrated in healthy human bile ducts with and without saline flushing. The laser-based video imaging can be switched to various modes to enhance tissue markers of disease, such as widefield fluorescence and enhanced spectral imaging. In parallel work, biochemical discrimination of tissue health in pig bile duct has been accomplished using fiberoptic delivery of pulsed UV illumination and time-resolved autofluorescence spectroscopic measurements. Implementation of time-resolved fluorescence spectroscopy for biochemical assessment of the bile duct wall is being done through a secondary endoscopic channel. Preliminary results indicate that adequate SNR levels (> 30 dB) can be achieved through a 50 micron fiber, which could serve as an optical biopsy probe. The SFE is an ideal mini-cholangioscope for integration of both tissue and molecular specific image contrast in the future. This will provide the physician with unprecedented abilities to target biopsy locations and perform endoscopically-guided therapies.

In vivo endoscopic optical coherence tomography by use of a rotational microelectromechanical system probe

NASA Astrophysics Data System (ADS)

Tran, Peter H.; Mukai, David S.; Brenner, Matthew; Chen, Zhongping

2004-06-01

A novel endoscopic optical coherence tomography probe was designed and constructed with a 1.9-mm microelectromechanical system (MEMS) motor. The new MEMS endoscopic probe design eliminates the need to couple the rotational energy from the proximal to the distal end of the probe. Furthermore, the endoscopic probe's sheath and fiber have the advantages of having a much smaller diameter and being more flexible than traditional endoscopes since no reinforcement is needed to couple the rotational torque. At the distal end, a prism mounted on a micromotor deflects the light rays to create a transverse circular-scanning pathway. Because our MEMS scanner does not require the coupling of a rotational single-mode fiber, a high scanning speed is possible while eliminating unstable optical signals caused by nonuniform coupling.

High-resolution handheld rigid endomicroscope based on full-field optical coherence tomography

NASA Astrophysics Data System (ADS)

Benoit a la Guillaume, Emilie; Martins, Franck; Boccara, Claude; Harms, Fabrice

2016-02-01

Full-field optical coherence tomography (FF-OCT) is a powerful tool for nondestructive assessment of biological tissue, i.e., for the structural examination of tissue in depth at a cellular resolution. Mostly known as a microscopy device for ex vivo analysis, FF-OCT has also been adapted to endoscopy setups since it shows good potential for in situ cancer diagnosis and biopsy guidance. Nevertheless, all the attempts to perform endoscopic FF-OCT imaging did not go beyond lab setups. We describe here, to the best of our knowledge, the first handheld FF-OCT endoscope based on a tandem interferometry assembly using incoherent illumination. A common-path passive imaging interferometer at the tip of an optical probe makes it robust and insensitive to environmental perturbations, and a low finesse Fabry-Perot processing interferometer guarantees a compact system. A good resolution (2.7 μm transverse and 6 μm axial) is maintained through the long distance, small diameter relay optics of the probe, and a good signal-to-noise ratio is achieved in a limited 100 ms acquisition time. High-resolution images and a movie of a rat brain slice have been recorded by moving the contact endoscope over the surface of the sample, allowing for tissue microscopic exploration at 20 μm under the surface. These promising ex vivo results open new perspectives for in vivo imaging of biological tissue, in particular, in the field of cancer and surgical margin assessment.

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

PubMed

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.

Miniaturized side-viewing imaging probe for fluorescence lifetime imaging (FLIM): validation with fluorescence dyes, tissue structural proteins and tissue specimens

PubMed Central

Elson, D S; Jo, J A

2007-01-01

We report a side viewing fibre-based endoscope that is compatible with intravascular imaging and fluorescence lifetime imaging microscopy (FLIM). The instrument has been validated through testing with fluorescent dyes and collagen and elastin powders using the Laguerre expansion deconvolution technique to calculate the fluorescence lifetimes. The instrument has also been tested on freshly excised unstained animal vascular tissues. PMID:19503759

Toward real-time quantification of fluorescence molecular probes using target/background ratio for guiding biopsy and endoscopic therapy of esophageal neoplasia.

PubMed

Jiang, Yang; Gong, Yuanzheng; Rubenstein, Joel H; Wang, Thomas D; Seibel, Eric J

2017-04-01

Multimodal endoscopy using fluorescence molecular probes is a promising method of surveying the entire esophagus to detect cancer progression. Using the fluorescence ratio of a target compared to a surrounding background, a quantitative value is diagnostic for progression from Barrett's esophagus to high-grade dysplasia (HGD) and esophageal adenocarcinoma (EAC). However, current quantification of fluorescent images is done only after the endoscopic procedure. We developed a Chan-Vese-based algorithm to segment fluorescence targets, and subsequent morphological operations to generate background, thus calculating target/background (T/B) ratios, potentially to provide real-time guidance for biopsy and endoscopic therapy. With an initial processing speed of 2 fps and by calculating the T/B ratio for each frame, our method provides quasireal-time quantification of the molecular probe labeling to the endoscopist. Furthermore, an automatic computer-aided diagnosis algorithm can be applied to the recorded endoscopic video, and the overall T/B ratio is calculated for each patient. The receiver operating characteristic curve was employed to determine the threshold for classification of HGD/EAC using leave-one-out cross-validation. With 92% sensitivity and 75% specificity to classify HGD/EAC, our automatic algorithm shows promising results for a surveillance procedure to help manage esophageal cancer and other cancers inspected by endoscopy.

Photoacoustic imaging of intestinal strictures: microscopic and macroscopic assessment in vivo (Conference Presentation)

NASA Astrophysics Data System (ADS)

Xu, Guan; Lei, Hao; Johnson, Laura A.; Moons, David S.; Ma, Teng; Zhou, Qifa; Rice, Michael D.; Ni, Jun; Wang, Xueding; Higgins, Peter D. R.

2017-03-01

The pathology of Crohn's disease (CD) is characterized by obstructing intestinal strictures because of inflammation (with high levels of hemoglobin), fibrosis (high levels of collagen), or a combination of both. Inflammatory strictures are medically treated. Fibrotic strictures have to be removed surgically. The accurate characterization of the strictures is therefore critical for the management of CD. Currently the comprehensive assessment of a stricture is difficult, as the standard diagnostic procedure, endoscopic biopsy, is superficial and with limited locations as well as depth. In our previous studies, photoacoustic imaging (PAI) has recovered the layered architectures and the relative content of the molecular components in human and animal tissues ex vivo. This study will investigate the capability of multispectral PAI in resolving the architecture and the molecular components of intestinal strictures in rats in vivo. PA images at 532, 1210 and 1310 nm targeting the strong optical absorption of hemoglobin, lipid and collagen were acquired using two approaches. A compact linear array, CL15-7, was used to transcutaneously acquire PA signals generated by the a fiber optics diffuser positioned within the inner lumen of the strictures. Another approach was to use an endoscopic capsule probe for acoustic resolution PA microscopy. The capsule probe is designed for human and therefore cannot fit into rat colon. The inner surface of the intestinal stricture was exposed and the probe was attached to the diseased location for imaging. The findings in PA images were confirmed by histology results.

High-sensitivity detection and monitoring of microcirculation using cutaneous and catheter probes for Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Yang, Victor X.; Gordon, M. L.; Qi, B.; Yue, E. Seng; Tang, S.; Bisland, Stuart K.; Pekar, J.; Lo, S.; Marcon, Norman E.; Wilson, B.; Vitkin, Alex

2003-07-01

Background: Currently clinical Doppler ultrasound cannot detect microvascular blood flow and it is difficult to provide depth discrimination using laser Doppler flowmetry. Doppler optical coherence tomography (DOCT) is a novel technique for noninvasive subsurface imaging of microcirculation and tissue structure. Aims: To design handheld and catheter-based DOCT probes for clinical cutaneous and endoscopic imaging. To develop signal processing techniques for real-time detection and quantification of microvascular blood flow. Methods: A DOCT system, with interchangeable cutaneous and catheter probes, was developed. The axial spatial resolution was 10 μm, and the velocity resolution was 20 μm/s, using a 1300 nm broadband infrared light. The system achieved real-time imaging with frame rates up to 32 Hz at 512 x 256 pixels per frame. We used the system to detect microcirculation in human skin and rat esophagus, and to monitor microvascular responses to photodynamic therapy (PDT) in a rat tumor model. Results: We present experimental results from in vivo DOCT imaging of microcirculation in human skin arterio-venous malformations (AVM), normal rat esophagus, and a rat gliosarcoma PDT model. In the PDT model, we followed microvascular responses to PDT and observed differences in the microcirculation during and after therapy, which can have important implications for PDT dosimetry and treatment optimization. Conclusions: To our knowledge, this is the first demonstration of endoscopic catheter-based DOCT detection of microcirculation in vivo. In addition, AVM can be detected using handheld cutaneous DOCT probes under clinical settings. DOCT may serve as a real-time monitoring tool for PDT dosimetry, especially for vascular targeting photosensitizers.

Minimally invasive multimode optical fiber microendoscope for deep brain fluorescence imaging

PubMed Central

Ohayon, Shay; Caravaca-Aguirre, Antonio; Piestun, Rafael; DiCarlo, James J.

2018-01-01

A major open challenge in neuroscience is the ability to measure and perturb neural activity in vivo from well defined neural sub-populations at cellular resolution anywhere in the brain. However, limitations posed by scattering and absorption prohibit non-invasive multi-photon approaches for deep (>2mm) structures, while gradient refractive index (GRIN) endoscopes are relatively thick and can cause significant damage upon insertion. Here, we present a novel micro-endoscope design to image neural activity at arbitrary depths via an ultra-thin multi-mode optical fiber (MMF) probe that has 5–10X thinner diameter than commercially available micro-endoscopes. We demonstrate micron-scale resolution, multi-spectral and volumetric imaging. In contrast to previous approaches, we show that this method has an improved acquisition speed that is sufficient to capture rapid neuronal dynamics in-vivo in rodents expressing a genetically encoded calcium indicator (GCaMP). Our results emphasize the potential of this technology in neuroscience applications and open up possibilities for cellular resolution imaging in previously unreachable brain regions. PMID:29675297

Design and performance of optical endoscopes for the early detection of cancer

NASA Astrophysics Data System (ADS)

Keenan, Maureen Molly

Cancer is a multistage, heterogeneous disease that develops through a series of genetic mutations. Early stage cancer is most responsive to treatment but can be the hardest to detect due to its small size, lack of definitive symptoms and potential location deep in the body. Whole body imaging methods, MRI/CT/PET, lack the necessary resolution to detect cellular level abnormalities. Optical methods, which have sufficient resolution, can be miniaturized into endoscopes, which are necessary to overcome limited penetration of light into tissue. By combining optical coherence tomography (OCT) and fluorescence imaging methods it is possible to create endoscopes sensitive to molecular and structural changes. I applied a dual-modality 2mm diameter rigid endoscope to the study of the natural history of colon cancer in a mouse model, and later applied this knowledge to the design and characterization of a 0.8 mm dual-modality flexible probe for use in human fallopian tubes. By using this endoscope, which is introduced through the natural orifice and is compatible with existing hysteroscopes, high-risk women could be screened in a procedure at a similar level of invasiveness as a colonoscopy. Therefore, the endoscope fills this gap in clinical care for women at high-risk for ovarian cancer.

Smart imaging of acute lung injury: exploration of myeloperoxidase activity using in vivo endoscopic confocal fluorescence microscopy.

PubMed

Chagnon, Frédéric; Bourgouin, Alexandra; Lebel, Réjean; Bonin, Marc-André; Marsault, Eric; Lepage, Martin; Lesur, Olivier

2015-09-15

The pathophysiology of acute lung injury (ALI) is well characterized, but its real-time assessment at bedside remains a challenge. When patients do not improve after 1 wk despite supportive therapies, physicians have to consider open lung biopsy (OLB) to identify the process(es) at play. Sustained inflammation and inadequate repair are often observed in this context. OLB is neither easy to perform in a critical setting nor exempt from complications. Herein, we explore intravital endoscopic confocal fluorescence microscopy (ECFM) of the lung in vivo combined with the use of fluorescent smart probe(s) activated by myeloperoxidase (MPO). MPO is a granular enzyme expressed by polymorphonuclear neutrophils (PMNs) and alveolar macrophages (AMs), catalyzing the synthesis of hypoclorous acid, a by-product of hydrogen peroxide. Activation of these probes was first validated in vitro in relevant cells (i.e., AMs and PMNs) and on MPO-non-expressing cells (as negative controls) and then tested in vivo using three rat models of ALI and real-time intravital imaging with ECFM. Semiquantitative image analyses revealed that in vivo probe-related cellular/background fluorescence was associated with corresponding enhanced lung enzymatic activity and was partly prevented by specific MPO inhibition. Additional ex vivo phenotyping was performed, confirming that fluorescent cells were neutrophil elastase(+) (PMNs) or CD68(+) (AMs). This work is a first step toward "virtual biopsy" of ALI without OLB. Copyright © 2015 the American Physiological Society.

Design of embedded endoscopic ultrasonic imaging system

NASA Astrophysics Data System (ADS)

Li, Ming; Zhou, Hao; Wen, Shijie; Chen, Xiodong; Yu, Daoyin

2008-12-01

Endoscopic ultrasonic imaging system is an important component in the endoscopic ultrasonography system (EUS). Through the ultrasonic probe, the characteristics of the fault histology features of digestive organs is detected by EUS, and then received by the reception circuit which making up of amplifying, gain compensation, filtering and A/D converter circuit, in the form of ultrasonic echo. Endoscopic ultrasonic imaging system is the back-end processing system of the EUS, with the function of receiving digital ultrasonic echo modulated by the digestive tract wall from the reception circuit, acquiring and showing the fault histology features in the form of image and characteristic data after digital signal processing, such as demodulation, etc. Traditional endoscopic ultrasonic imaging systems are mainly based on image acquisition and processing chips, which connecting to personal computer with USB2.0 circuit, with the faults of expensive, complicated structure, poor portability, and difficult to popularize. To against the shortcomings above, this paper presents the methods of digital signal acquisition and processing specially based on embedded technology with the core hardware structure of ARM and FPGA for substituting the traditional design with USB2.0 and personal computer. With built-in FIFO and dual-buffer, FPGA implement the ping-pong operation of data storage, simultaneously transferring the image data into ARM through the EBI bus by DMA function, which is controlled by ARM to carry out the purpose of high-speed transmission. The ARM system is being chosen to implement the responsibility of image display every time DMA transmission over and actualizing system control with the drivers and applications running on the embedded operating system Windows CE, which could provide a stable, safe and reliable running platform for the embedded device software. Profiting from the excellent graphical user interface (GUI) and good performance of Windows CE, we can not only clearly show 511×511 pixels ultrasonic echo images through application program, but also provide a simple and friendly operating interface with mouse and touch screen which is more convenient than the traditional endoscopic ultrasonic imaging system. Including core and peripheral circuits of FPGA and ARM, power network circuit and LCD display circuit, we designed the whole embedded system, achieving the desired purpose by implementing ultrasonic image display properly after the experimental verification, solving the problem of hugeness and complexity of the traditional endoscopic ultrasonic imaging system.

Which electrode? A comparison of four endoscopic methods of electrocoagulation in experimental bleeding ulcers.

PubMed Central

Swain, C P; Mills, T N; Shemesh, E; Dark, J M; Lewin, M R; Clifton, J S; Northfield, T C; Cotton, P B; Salmon, P R

1984-01-01

Several inexpensive endoscopic methods of electrocoagulation have been advocated for treatment of gastrointestinal haemorrhage. We compared four types of electrode: dry monopolar - Cameron Miller (M), liquid monopolar - Storz (L), bipolar - Bicap ACMI (B), and heater probe - Seattle (H). The electrical and thermal properties of these probes were studied using computerised monitoring of energy deposition and their efficacy and safety was tested in a randomised study in 140 experimental canine gastric ulcers. At optimal pulse settings 20J (M), 70J (L), 17J (B), 15J (H), effective haemostasis was achieved in all ulcers, the mean number of pulses being M5, L6, H6 and B11, the first three requiring significantly (p less than 0.01) less pulse than B. Relative safety of the electrodes was assessed by comparing the incidence of full thickness damage at histology: B24%, H20%, L58% and M69%; B and H proving significantly (p less than 0.01) safer than L and M. Sticking was assessed as H greater than B greater than M much greater than L. Insensitivity to extreme angulation and force of application was assessed as L greater than B greater than M (H is preset). Of the two safer electrodes the heater probe was more effective than the bipolar probe. Despite its greater tendency to stick than the other devices, the heater probe appeared the most promising of the endoscopic electrodes tested. Images Fig. 1 Fig. 2 PMID:6510772

Proof-of-concept of a laser mounted endoscope for touch-less navigated procedures

PubMed Central

Kral, Florian; Gueler, Oezguer; Perwoeg, Martina; Bardosi, Zoltan; Puschban, Elisabeth J; Riechelmann, Herbert; Freysinger, Wolfgang

2013-01-01

Background and Objectives During navigated procedures a tracked pointing device is used to define target structures in the patient to visualize its position in a registered radiologic data set. When working with endoscopes in minimal invasive procedures, the target region is often difficult to reach and changing instruments is disturbing in a challenging, crucial moment of the procedure. We developed a device for touch less navigation during navigated endoscopic procedures. Materials and Methods A laser beam is delivered to the tip of a tracked endoscope angled to its axis. Thereby the position of the laser spot in the video-endoscopic images changes according to the distance between the tip of the endoscope and the target structure. A mathematical function is defined by a calibration process and is used to calculate the distance between the tip of the endoscope and the target. The tracked tip of the endoscope and the calculated distance is used to visualize the laser spot in the registered radiologic data set. Results In comparison to the tracked instrument, the touch less target definition with the laser spot yielded in an over and above error of 0.12 mm. The overall application error in this experimental setup with a plastic head was 0.61 ± 0.97 mm (95% CI −1.3 to +2.5 mm). Conclusion Integrating a laser in an endoscope and then calculating the distance to a target structure by image processing of the video endoscopic images is accurate. This technology eliminates the need for tracked probes intraoperatively and therefore allows navigation to be integrated seamlessly in clinical routine. However, it is an additional chain link in the sequence of computer-assisted surgery thus influencing the application error. Lasers Surg. Med. 45:377–382, 2013. © 2013 Wiley Periodicals, Inc. PMID:23737122

Miniaturized ultrasound imaging probes enabled by CMUT arrays with integrated frontend electronic circuits.

PubMed

Khuri-Yakub, B T; Oralkan, Omer; Nikoozadeh, Amin; Wygant, Ira O; Zhuang, Steve; Gencel, Mustafa; Choe, Jung Woo; Stephens, Douglas N; de la Rama, Alan; Chen, Peter; Lin, Feng; Dentinger, Aaron; Wildes, Douglas; Thomenius, Kai; Shivkumar, Kalyanam; Mahajan, Aman; Seo, Chi Hyung; O'Donnell, Matthew; Truong, Uyen; Sahn, David J

2010-01-01

Capacitive micromachined ultrasonic transducer (CMUT) arrays are conveniently integrated with frontend integrated circuits either monolithically or in a hybrid multichip form. This integration helps with reducing the number of active data processing channels for 2D arrays. This approach also preserves the signal integrity for arrays with small elements. Therefore CMUT arrays integrated with electronic circuits are most suitable to implement miniaturized probes required for many intravascular, intracardiac, and endoscopic applications. This paper presents examples of miniaturized CMUT probes utilizing 1D, 2D, and ring arrays with integrated electronics.

Lens-free all-fiber probe with an optimized output beam for optical coherence tomography.

PubMed

Ding, Zhihua; Qiu, Jianrong; Shen, Yi; Chen, Zhiyan; Bao, Wen

2017-07-15

A high-efficiency lensless all-fiber probe for optical coherence tomography (OCT) is presented. The probe is composed of a segment of large-core multimode fiber (MMF), a segment of tapered MMF, and a length of single-mode fiber (SMF). A controllable output beam can be designed by a simple adjustment of its probe structure parameters (PSPs), instead of the selection of fibers with different optical parameters. A side-view probe with a diameter of 340 μm and a rigid length of 6.37 mm was fabricated, which provides an effective imaging range of ∼0.6  mm with a full width at half-maximum beam diameter of less than 30 μm. The insertion loss of the probe was measured to be 0.81 dB, ensuring a high sensitivity of 102.25 dB. Satisfactory images were obtained by the probe-based OCT system, demonstrating the feasibility of the probe for endoscopic OCT applications.

In-vivo gingival sulcus imaging using full-range, complex-conjugate-free, endoscopic spectral domain optical coherence tomography

NASA Astrophysics Data System (ADS)

Huang, Yong; Zhang, Kang; Yi, WonJin; Kang, Jin U.

2012-01-01

Frequent monitoring of gingival sulcus will provide valuable information for judging the presence and severity of periodontal disease. Optical coherence tomography, as a 3D high resolution high speed imaging modality is able to provide information for pocket depth, gum contour, gum texture, gum recession simultaneously. A handheld forward-viewing miniature resonant fiber-scanning probe was developed for in-vivo gingival sulcus imaging. The fiber cantilever driven by magnetic force vibrates at resonant frequency. A synchronized linear phase-modulation was applied in the reference arm by the galvanometer-driven reference mirror. Full-range, complex-conjugate-free, real-time endoscopic SD-OCT was achieved by accelerating the data process using graphics processing unit. Preliminary results showed a real-time in-vivo imaging at 33 fps with an imaging range of lateral 2 mm by depth 3 mm. Gap between the tooth and gum area was clearly visualized. Further quantification analysis of the gingival sulcus will be performed on the image acquired.

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

PubMed

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.

Simple, monolithic optical element for forward-viewing spectrally encoded endoscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Do, Dukho; Kang, Dongkyun; Ikuta, Mitsuhiro; Tearney, Guillermo J.

2016-03-01

Spectrally encoded endoscopy (SEE) is a miniature endoscopic technology that can acquire images of internal organs through a hair-thin probe. While most previously described SEE probes have been side viewing, forward-view (FV)-SEE is advantageous in certain clinical applications as it provides more natural navigation of the probe and has the potential to provide a wider field of view. Prior implementations of FV-SEE used multiple optical elements that increase fabrication complexity and may diminish the robustness of the device. In this paper, we present a new design that uses a monolithic optical element to realize FV-SEE imaging. The optical element is specially designed spacer, fabricated from a 500-μm-glass rod that has a mirror surface on one side and a grating stamped on its distal end. The mirror surface is used to change the incident angle on the grating to diffract the shortest wavelength of the spectrum so that it is parallel to the optical axis. Rotating the SEE optics creates a circular FV-SEE image. Custom-designed software processes FV-SEE images into circular images, which are displayed in real-time. In order to demonstrate this new design, we have constructed the FV-SEE optical element using a 1379 lines/mm diffraction grating. When illuminated with a source with a spectral bandwidth of 420-820 nm, the FV-SEE optical element provides 678 resolvable points per line. The imaging performance of the FV-SEE device was tested by imaging a USAF resolution target. SEE images showed that this new approach generates high quality images in the forward field with a field of view of 58°. Results from this preliminary study demonstrate that we can realize FV-SEE imaging with simple, monolithic, miniature optical element. The characteristics of this FV-SEE configuration will facilitate the development of robust miniature endoscopes for a variety of medical imaging applications.

Miniaturized Ultrasound Imaging Probes Enabled by CMUT Arrays with Integrated Frontend Electronic Circuits

PubMed Central

Khuri-Yakub, B. (Pierre) T.; Oralkan, Ömer; Nikoozadeh, Amin; Wygant, Ira O.; Zhuang, Steve; Gencel, Mustafa; Choe, Jung Woo; Stephens, Douglas N.; de la Rama, Alan; Chen, Peter; Lin, Feng; Dentinger, Aaron; Wildes, Douglas; Thomenius, Kai; Shivkumar, Kalyanam; Mahajan, Aman; Seo, Chi Hyung; O’Donnell, Matthew; Truong, Uyen; Sahn, David J.

2010-01-01

Capacitive micromachined ultrasonic transducer (CMUT) arrays are conveniently integrated with frontend integrated circuits either monolithically or in a hybrid multichip form. This integration helps with reducing the number of active data processing channels for 2D arrays. This approach also preserves the signal integrity for arrays with small elements. Therefore CMUT arrays integrated with electronic circuits are most suitable to implement miniaturized probes required for many intravascular, intracardiac, and endoscopic applications. This paper presents examples of miniaturized CMUT probes utilizing 1D, 2D, and ring arrays with integrated electronics. PMID:21097106

In vivo brain imaging using a portable 3.9 gram two-photon fluorescence microendoscope

NASA Astrophysics Data System (ADS)

Flusberg, Benjamin A.; Jung, Juergen C.; Cocker, Eric D.; Anderson, Erik P.; Schnitzer, Mark J.

2005-09-01

We introduce a compact two-photon fluorescence microendoscope based on a compound gradient refractive index endoscope probe, a DC micromotor for remote adjustment of the image plane, and a flexible photonic bandgap fiber for near distortion-free delivery of ultrashort excitation pulses. The imaging head has a mass of only 3.9 g and provides micrometer-scale resolution. We used portable two-photon microendoscopy to visualize hippocampal blood vessels in the brains of live mice.

Clinically compatible flexible wide-field multi-color fluorescence endoscopy with a porcine colon model

PubMed Central

Oh, Gyugnseok; Park, Youngrong; Yoo, Su Woong; Hwang, Soonjoo; Chin-Yu, Alexey V. Dan; Ryu, Yeon-Mi; Kim, Sang-Yeob; Do, Eun-Ju; Kim, Ki Hean; Kim, Sungjee; Myung, Seung-Jae; Chung, Euiheon

2017-01-01

Early detection of structural or molecular changes in dysplastic epithelial tissues is crucial for cancer screening and surveillance. Multi-targeting molecular endoscopic fluorescence imaging may improve noninvasive detection of precancerous lesions in the colon. Here, we report the first clinically compatible, wide-field-of-view, multi-color fluorescence endoscopy with a leached fiber bundle scope using a porcine model. A porcine colon model that resembles the human colon is used for the detection of surrogate tumors composed of multiple biocompatible fluorophores (FITC, ICG, and heavy metal-free quantum dots (hfQDs)). With an ex vivo porcine colon tumor model, molecular imaging with hfQDs conjugated with MMP14 antibody was achieved by spraying molecular probes on a mucosa layer that contains xenograft tumors. With an in vivo porcine colon embedded with surrogate tumors, target-to-background ratios of 3.36 ± 0.43, 2.70 ± 0.72, and 2.10 ± 0.13 were achieved for FITC, ICG, and hfQD probes, respectively. This promising endoscopic technology with molecular contrast shows the capacity to reveal hidden tumors and guide treatment strategy decisions. PMID:28270983

Sprayable enzyme-activatable fluorescent probes: kinetic mapping using dynamic fluorescence imaging can help detecting tiny cancer foci (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kobayashi, Hisataka

2017-02-01

Optical fluorescence-guided imaging is increasingly used to guide surgery and endoscopic procedures. Sprayable enzyme-activatable probes are particularly useful because of high target-to-background ratios that increase sensitivity for tiny cancer foci. However, green fluorescent activatable probes suffers from interference from autofluorescence found in biological tissue. Dynamic imaging followed by the kinetic analysis could be detected local enzyme activity and used to differentiate specific fluorescence arising from an activated probe in a tumor from autofluorescence in background tissues especially when low concentrations of the dye are applied to detect tiny cancer foci. Serial fluorescence imaging was performed using various concentrations of γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG) which was sprayed on the peritoneal surface with tiny implants of SHIN3-dsRed ovarian cancer tumors. Temporal differences in signal between specific green fluorescence in cancer foci and non-specific autofluorescence in background tissue was measured and processed into three kinetic maps reflecting maximum fluorescence signal (MF), wash-in rate (WIR), and area under the curve (AUC), respectively. Especially at lower concentrations, kinetic maps derived from dynamic fluorescence imaging were clearly superior to unprocessed images for detection small cancer foci.

Lung vasculature imaging using speckle variance optical coherence tomography

NASA Astrophysics Data System (ADS)

Cua, Michelle; Lee, Anthony M. D.; Lane, Pierre M.; McWilliams, Annette; Shaipanich, Tawimas; MacAulay, Calum E.; Yang, Victor X. D.; Lam, Stephen

2012-02-01

Architectural changes in and remodeling of the bronchial and pulmonary vasculature are important pathways in diseases such as asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. However, there is a lack of methods that can find and examine small bronchial vasculature in vivo. Structural lung airway imaging using optical coherence tomography (OCT) has previously been shown to be of great utility in examining bronchial lesions during lung cancer screening under the guidance of autofluorescence bronchoscopy. Using a fiber optic endoscopic OCT probe, we acquire OCT images from in vivo human subjects. The side-looking, circumferentially-scanning probe is inserted down the instrument channel of a standard bronchoscope and manually guided to the imaging location. Multiple images are collected with the probe spinning proximally at 100Hz. Due to friction, the distal end of the probe does not spin perfectly synchronous with the proximal end, resulting in non-uniform rotational distortion (NURD) of the images. First, we apply a correction algorithm to remove NURD. We then use a speckle variance algorithm to identify vasculature. The initial data show a vascaulture density in small human airways similar to what would be expected.

Dynamic focus-tracking MEMS scanning micromirror with low actuation voltages for endoscopic imaging.

PubMed

Strathman, Matthew; Liu, Yunbo; Li, Xingde; Lin, Lih Y

2013-10-07

We demonstrate a 3-D scanning micromirror device that combines 2-D beam scanning with focus control in the same device using micro-electro-mechanical-systems (MEMS) technology. 2-D beam scanning is achieved with a biaxial gimbal structure and focus control is obtained with a deformable mirror membrane surface. The micromirror with 800 micrometer diameter is designed to be sufficiently compact and efficient so that it can be incorporated into an endoscopic imaging probe in the future. The design, fabrication and characterization of the device are described in this paper. Using the focus-tracking MEMS scanning mirror, we achieved an optical scanning range of >16 degrees with <40 V actuation voltage at resonance and a tunable focal length between infinity and 25 mm with <100V applied bias.

Multimode-Optical-Fiber Imaging Probe

NASA Technical Reports Server (NTRS)

Jackson, Deborah

2000-01-01

Currently, endoscopic surgery uses single-mode fiber-bundles to obtain in vivo image information inside orifices of the body. This limits their use to the larger natural bodily orifices and to surgical procedures where there is plenty of room for manipulation. The knee joint, for example can be easily viewed with a fiber optic viewer, but joints in the finger cannot. However, there are a host of smaller orifices where fiber endoscopy would play an important role if a cost effective fiber probe were developed with small enough dimensions (< 250 microns). Examples of beneficiaries of micro-endoscopes are the treatment of the Eustatian tube of the middle ear, the breast ducts, tear ducts, coronary arteries, fallopian tubes, as well as the treatment of salivary duct parotid disease, and the neuro endoscopy of the ventricles and spinal canal. To solve this problem, this work describes an approach for recovering images from. tightly confined spaces using multimode fibers and analytically demonstrates that the concept is sound. The proof of concept draws upon earlier works that concentrated on image recovery after two-way transmission through a multimode fiber as well as work that demonstrated the recovery of images after one-way transmission through a multimode fiber. Both relied on generating a phase conjugated wavefront which was predistorted with the characteristics of the fiber. The described approach also relies on generating a phase conjugated wavefront, but utilizes two fibers to capture the image at some intermediate point (accessible by the fibers, but which is otherwise visually unaccessible).

Multimode-Optical-Fiber Imaging Probe

NASA Technical Reports Server (NTRS)

Jackson, Deborah

1999-01-01

Currently, endoscopic surgery uses single-mode fiber-bundles to obtain in vivo image information inside the orifices of the body. This limits their use to the larger natural orifices and to surgical procedures where there is plenty of room for manipulation. The knee joint, for example, can be easily viewed with a fiber optic viewer, but joints in the finger cannot. However, there are a host of smaller orifices where fiber endoscopy would play an important role if a cost effective fiber probe were developed with small enough dimensions (less than or equal to 250 microns). Examples of beneficiaries of micro-endoscopes are the treatment of the Eustatian tube of the middle ear, the breast ducts, tear ducts, coronary arteries, fallopian tubes, as well as the treatment of salivary duct parotid disease, and the neuro endoscopy of the ventricles and spinal canal. This work describes an approach for recovering images from tightly confined spaces using multimode. The concept draws upon earlier works that concentrated on image recovery after two-way transmission through a multimode fiber as well as work that demonstrated the recovery of images after one-way transmission through a multimode fiber. Both relied on generating a phase conjugated wavefront, which was predistorted with the characteristics of the fiber. The approach described here also relies on generating a phase conjugated wavefront, but utilizes two fibers to capture the image at some intermediate point (accessible by the fibers, but which is otherwise visually inaccessible).

Endoscopically-controlled electrohydraulic intracorporeal shock wave lithotripsy (EISL) of salivary stones.

PubMed

Königsberger, R; Feyh, J; Goetz, A; Kastenbauer, E

1993-02-01

Twenty-nine patients with salivary stones were treated with the endoscopically-controlled electrohydraulic shock wave lithotripsy (EISL). This new minimally invasive treatment of sialolithiasis is performed under local anesthesia on an outpatient basis with little inconvenience to the patient. For endoscopy, a flexible fibroscope with an additional probe to generate shock waves is placed into the submandibular duct and advanced until the stone is identified. For shock wave-induced stone disintegration, the probe electrode must be placed 1 mm in front of the concrement. The shock waves are generated by a sparkover at the tip of the probe. By means of the endoscopically-controlled shock wave lithotripsy it was possible to achieve complete stone fragmentation in 20 out of 29 patients without serious side effects. In three patients, only partial stone fragmentation could be achieved due to the stone quality. Endoscopically-controlled electrohydraulic intracorporeal shock wave lithotripsy represents a novel minimally invasive therapy for endoscopically accessible salivary gland stones. The advantage in comparison to the endoscopically-controlled laser lithotripsy will be discussed.

Fluorescence-based endoscopic imaging of Thomsen-Friedenreich antigen to improve early detection of colorectal cancer.

PubMed

Sakuma, Shinji; Yu, James Y H; Quang, Timothy; Hiwatari, Ken-Ichiro; Kumagai, Hironori; Kao, Stephanie; Holt, Alex; Erskind, Jalysa; McClure, Richard; Siuta, Michael; Kitamura, Tokio; Tobita, Etsuo; Koike, Seiji; Wilson, Kevin; Richards-Kortum, Rebecca; Liu, Eric; Washington, Kay; Omary, Reed; Gore, John C; Pham, Wellington

2015-03-01

Thomsen-Friedenreich (TF) antigen belongs to the mucin-type tumor-associated carbohydrate antigen. Notably, TF antigen is overexpressed in colorectal cancer (CRC) but is rarely expressed in normal colonic tissue. Increased TF antigen expression is associated with tumor invasion and metastasis. In this study, we sought to validate a novel nanobeacon for imaging TF-associated CRC in a preclinical animal model. We developed and characterized the nanobeacon for use with fluorescence colonoscopy. In vivo imaging was performed on an orthotopic rat model of CRC. Both white light and fluorescence colonoscopy methods were utilized to establish the ratio-imaging index for the probe. The nanobeacon exhibited specificity for TF-associated cancer. Fluorescence colonoscopy using the probe can detect lesions at the stage which is not readily confirmed by conventional visualization methods. Further, the probe can report the dynamic change of TF expression as tumor regresses during chemotherapy. Data from this study suggests that fluorescence colonoscopy can improve early CRC detection. Supplemented by the established ratio-imaging index, the probe can be used not only for early detection, but also for reporting tumor response during chemotherapy. Furthermore, since the data obtained through in vivo imaging confirmed that the probe was not absorbed by the colonic mucosa, no registered toxicity is associated with this nanobeacon. Taken together, these data demonstrate the potential of this novel probe for imaging TF antigen as a biomarker for the early detection and prediction of the progression of CRC at the molecular level. © 2014 UICC.

Real-time high-velocity resolution color Doppler OCT

NASA Astrophysics Data System (ADS)

Westphal, Volker; Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

2001-05-01

Color Doppler optical coherence tomography (CDOCT), also called Optical Doppler Tomography) is a noninvasive optical imaging technique, which allows for micron-scale physiological flow mapping simultaneous with morphological OCT imaging. Current systems for real-time endoscopic optical coherence tomography (EOCT) would be enhanced by the capability to visualize sub-surface blood flow for applications in early cancer diagnosis and the management of bleeding ulcers. Unfortunately, previous implementations of CDOCT have either been sufficiently computationally expensive (employing Fourier or Hilbert transform techniques) to rule out real-time imaging of flow, or have been restricted to imaging of excessively high flow velocities when used in real time. We have developed a novel Doppler OCT signal-processing strategy capable of imaging physiological flow rates in real time. This strategy employs cross-correlation processing of sequential A-scans in an EOCT image, as opposed to autocorrelation processing as described previously. To measure Doppler shifts in the kHz range using this technique, it was necessary to stabilize the EOCT interferometer center frequency, eliminate parasitic phase noise, and to construct a digital cross correlation unit able to correlate signals of megahertz bandwidth by a fixed lag of up to a few ms. The performance of the color Doppler OCT system was demonstrated in a flow phantom, demonstrating a minimum detectable flow velocity of ~0.8 mm/s at a data acquisition rate of 8 images/second (with 480 A-scans/image) using a handheld probe. Dynamic flow as well as using it freehanded was shown. Flow was also detectable in a phantom in combination with a clinical usable endoscopic probe.

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

NASA Astrophysics Data System (ADS)

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

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

PubMed

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.

All-optical endoscopic probe for high resolution 3D photoacoustic tomography

NASA Astrophysics Data System (ADS)

Ansari, R.; Zhang, E.; Desjardins, A. E.; Beard, P. C.

2017-03-01

A novel all-optical forward-viewing photoacoustic probe using a flexible coherent fibre-optic bundle and a Fabry- Perot (FP) ultrasound sensor has been developed. The fibre bundle, along with the FP sensor at its distal end, synthesizes a high density 2D array of wideband ultrasound detectors. Photoacoustic waves arriving at the sensor are spatially mapped by optically scanning the proximal end face of the bundle in 2D with a CW wavelength-tunable interrogation laser. 3D images are formed from the detected signals using a time-reversal image reconstruction algorithm. The system has been characterized in terms of its PSF, noise-equivalent pressure and field of view. Finally, the high resolution 3D imaging capability has been demonstrated using arbitrary shaped phantoms and duck embryo.

Miniature all-optical probe for photoacoustic and ultrasound dual-modality imaging

NASA Astrophysics Data System (ADS)

Li, Guangyao; Guo, Zhendong; Chen, Sung-Liang

2018-02-01

Photoacoustic (PA) imaging forms an image based on optical absorption contrasts with ultrasound (US) resolution. In contrast, US imaging is based on acoustic backscattering to provide structural information. In this study, we develop a miniature all-optical probe for high-resolution PA-US dual-modality imaging over a large imaging depth range. The probe employs three individual optical fibers (F1-F3) to achieve optical generation and detection of acoustic waves for both PA and US modalities. To offer wide-angle laser illumination, fiber F1 with a large numerical aperture (NA) is used for PA excitation. On the other hand, wide-angle US waves are generated by laser illumination on an optically absorbing composite film which is coated on the end face of fiber F2. Both the excited PA and backscattered US waves are detected by a Fabry-Pérot cavity on the tip of fiber F3 for wide-angle acoustic detection. The wide angular features of the three optical fibers make large-NA synthetic aperture focusing technique possible and thus high-resolution PA and US imaging. The probe diameter is less than 2 mm. Over a depth range of 4 mm, lateral resolutions of PA and US imaging are 104-154 μm and 64-112 μm, respectively, and axial resolutions of PA and US imaging are 72-117 μm and 31-67 μm, respectively. To show the imaging capability of the probe, phantom imaging with both PA and US contrasts is demonstrated. The results show that the probe has potential for endoscopic and intravascular imaging applications that require PA and US contrast with high resolution.

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

NASA Astrophysics Data System (ADS)

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.

Dynamic focus-tracking MEMS scanning micromirror with low actuation voltages for endoscopic imaging

PubMed Central

Strathman, Matthew; Liu, Yunbo; Li, Xingde; Lin, Lih Y.

2013-01-01

We demonstrate a 3-D scanning micromirror device that combines 2-D beam scanning with focus control in the same device using micro-electro-mechanical-systems (MEMS) technology. 2-D beam scanning is achieved with a biaxial gimbal structure and focus control is obtained with a deformable mirror membrane surface. The micromirror with 800 micrometer diameter is designed to be sufficiently compact and efficient so that it can be incorporated into an endoscopic imaging probe in the future. The design, fabrication and characterization of the device are described in this paper. Using the focus-tracking MEMS scanning mirror, we achieved an optical scanning range of >16 degrees with <40 V actuation voltage at resonance and a tunable focal length between infinity and 25 mm with <100V applied bias. PMID:24104304

Passive OCT probe head for 3D duct inspection

NASA Astrophysics Data System (ADS)

Ford, Helen D.; Tatam, Ralph P.

2013-09-01

A passive, endoscopic optical coherence tomography (OCT) probe has been demonstrated, incorporating an imaging fibre bundle and 45° conical mirror, and with no electromechanical components at the probe tip. Circular scanning, of the beam projected onto the proximal face of the imaging bundle, produces a corresponding circular scan at the distal end of the bundle. The beam is turned through 90° by the conical mirror and converted into a radially-scanned sample beam, permitting circumferential OCT scanning in quasi-cylindrical ducts. OCT images, displayed as polar plots and as 3D reconstructions, are presented, showing the internal profile of a metallic test sample containing a 660 µm step in the internal wall. Results have been acquired using two methods: one that makes use of multiple beam-circle diameters, and a mechanical ‘pull-back’ technique. The effects of the convex surface of the conical mirror on spatial resolution are discussed, with suggested working distances given for different application regimes.

Correlation of endoscopic optical coherence tomography with histology

NASA Astrophysics Data System (ADS)

Westphal, Volker; Rollins, Andrew M.; Willis, Joseph; Sivak, Michael J., Jr.; Izatt, Joseph A.

2000-04-01

Optical Coherence Tomography (OCT) is a noninvasive optical imaging technique that allows high-resolution cross- sectional imaging of tissue microstructure. We have recently developed a system for endoscopic OCT (EOCT) to examine the gastrointestinal tract of humans in vivo. Compared to endoscopic ultrasonic devices it offers a higher resolution and does not require coupling gels or fluids. EOCT may lead to a versatile tool for biopsy site selection or optical biopsy itself. The EOCT unit is comprised of an interferometer unit with a high speed scanning reference arm and an endoscopically compatible radially scanning probe as the sample arm. Fast data acquisition allows real-time display. Temporal averaging for speckle reduction and a transformation to correct nonlinear scanning were included in the EOCT control software, both in real-time. During in vivo clinical trials, we have observe the structure of the mucosa and submucosa in several gastrointestinal organs as well as glands, blood vessels, pits, villi and crypts. The purpose of this study was to correlate images acquired in vitro with EOCT to corresponding histological sections. EOCT images were obtained on fresh specimens, which were then fixed in formalin and submitted for standard histology. Tissues examined were normal specimens, which were then fixed in formalin and submitted for standard histology. Tissues examined were normal specimens of stomach, ileum, colon and rectum. It was shown that he thickness of the mucosa correlates well with the first bright layer in EOCT. The R2-value was determined to be 0.69. The submucosa and the muscularis propria could be identified. Furthermore, we were able to show the effect of pressure on the tissue on the visible details in the EOCT images.

Endoscopic ultrasound description of liver segmentation and anatomy.

PubMed

Bhatia, Vikram; Hijioka, Susumu; Hara, Kazuo; Mizuno, Nobumasa; Imaoka, Hiroshi; Yamao, Kenji

2014-05-01

Endoscopic ultrasound (EUS) can demonstrate the detailed anatomy of the liver from the transgastric and transduodenal routes. Most of the liver segments can be imaged with EUS, except the right posterior segments. The intrahepatic vascular landmarks include the major hepatic veins, portal vein radicals, hepatic arterial branches, and the inferior vena cava, and the venosum and teres ligaments are other important intrahepatic landmarks. The liver hilum and gallbladder serve as useful surface landmarks. Deciphering liver segmentation and anatomy by EUS requires orienting the scan planes with these landmarkstructures, and is different from the static cross-sectional radiological images. Orientation during EUS requires appreciation of the numerous scan planes possible in real-time, and the direction of scanning from the stomach and duodenal bulb. We describe EUS imaging of the liver with a curved linear probe in a step-by-step approach, with the relevant anatomical details, potential applications, and pitfalls of this novel EUS application. © 2013 The Authors. Digestive Endoscopy © 2013 Japan Gastroenterological Endoscopy Society.

A novel integration of spectral-domain optical-coherence-tomography and laser-ablation system for precision treatment.

PubMed

Fan, Yingwei; Zhang, Boyu; Chang, Wei; Zhang, Xinran; Liao, Hongen

2018-03-01

Complete resection of diseased lesions reduces the recurrence of cancer, making it critical for surgical treatment. However, precisely resecting residual tumors is a challenge during operation. A novel integrated spectral-domain optical-coherence-tomography (SD-OCT) and laser-ablation therapy system for soft-biological-tissue resection is proposed. This is a prototype optical integrated diagnosis and therapeutic system as well as an optical theranostics system. We develop an optical theranostics system, which integrates SD-OCT, a laser-ablation unit, and an automatic scanning platform. The SD-OCT image of biological tissue provides an intuitive and clear view for intraoperative diagnosis and monitoring in real time. The effect of laser ablation is analyzed using a quantitative mathematical model. The automatic endoscopic scanning platform combines an endoscopic probe and an SD-OCT sample arm to provide optical theranostic scanning motion. An optical fiber and a charge-coupled device camera are integrated into the endoscopic probe, allowing detection and coupling of the OCT-aiming beam and laser spots. The integrated diagnostic and therapeutic system combines SD-OCT imaging and laser-ablation modules with an automatic scanning platform. OCT imaging, laser-ablation treatment, and the integration and control of diagnostic and therapeutic procedures were evaluated by performing phantom experiments. Furthermore, SD-OCT-guided laser ablation provided precision laser ablation and resection for the malignant lesions in soft-biological-tissue-lesion surgery. The results demonstrated that the appropriate laser-radiation power and duration time were 10 W and 10 s, respectively. In the laser-ablation evaluation experiment, the error reached approximately 0.1 mm. Another validation experiment was performed to obtain OCT images of the pre- and post-ablated craters of ex vivo porcine brainstem. We propose an optical integrated diagnosis and therapeutic system. The primary experimental results show the high efficiency and feasibility of our theranostics system, which is promising for realizing accurate resection of tumors in vivo and in situ in the future.

Confocal laser endomicroscopy in the "in vivo" histological diagnosis of the gastrointestinal tract.

PubMed

De Palma, Giovanni D

2009-12-14

Recent technological advances in miniaturization have allowed for a confocal scanning microscope to be integrated into a conventional flexible endoscope, or into trans-endoscopic probes, a technique now known as confocal endomicroscopy or confocal laser endomicroscopy. This newly-developed technology has enabled endoscopists to collect real-time in vivo histological images or "virtual biopsies" of the gastrointestinal mucosa during endoscopy, and has stimulated significant interest in the application of this technique in clinical gastroenterology. This review aims to evaluate the current data on the technical aspects and the utility of this new technology in clinical gastroenterology and its potential impact in the future, particularly in the screening or surveillance of gastrointestinal neoplasia.

Design and testing of an endoscopic photoacoustic probe for determination of treatment depth after photodynamic therapy

NASA Astrophysics Data System (ADS)

Viator, John A.; Paltauf, Guenther; Jacques, Steven L.; Prahl, Scott A.

2001-06-01

An endoscopic photoacoustic probe is designed and tested for use in PDT treatment of esophageal cancer. The probe, measuring less than 2.5 mm in diameter, was designed to fit within the lumen of an endoscope that will be inserted into an esophagus after PDT. PDT treatment results in a blanched, necrotic layer of cancerous tissue over a healthy, deeper layer of perfused tissue. The photoacoustic probe was designed to use acoustic propagation time to determine the thickness of the blanched surface of the esophagus, which corresponds to treatment depth. A side-firing 600 micrometers fiber delivered 532 nm laser light to induce acoustic waves in the perfused layer of the esophagus beneath the blanched (treated) layer. A PVDF transducer detected the induced acoustic waves and transmitted the signal to an oscilloscope. The probe was tested on clear and turbid tissue phantom layers over an optically absorbing dye solution.

Targeted Endoscopic Imaging

PubMed Central

Li, Meng; Wang, Thomas D

2011-01-01

Summary Endoscopy has undergone explosive technological growth in over recent years, and with the emergence of targeted imaging, its truly transformative power and impact in medicine lies just over the horizon. Today, our ability to see inside the digestive tract with medical endoscopy is headed toward exciting crossroads. The existing paradigm of making diagnostic decisions based on observing structural changes and identifying anatomical landmarks may soon be replaced by visualizing functional properties and imaging molecular expression. In this novel approach, the presence of intracellular and cell surface targets unique to disease are identified and used to predict the likelihood of mucosal transformation and response to therapy. This strategy can result in the development of new methods for early cancer detection, personalized therapy, and chemoprevention. This targeted approach will require further development of molecular probes and endoscopic instruments, and will need support from the FDA for streamlined regulatory oversight. Overall, this molecular imaging modality promises to significantly broaden the capabilities of the gastroenterologist by providing a new approach to visualize the mucosa of the digestive tract in a manner that has never been seen before. PMID:19423025

Peroral endoscopic pyloromyotomy is efficacious and safe for refractory gastroparesis: prospective trial with assessment of pyloric function.

PubMed

Jacques, Jérémie; Pagnon, Lauriane; Hure, Florent; Legros, Romain; Crepin, Sabrina; Fauchais, Anne-Laure; Palat, Sylvain; Ducrotté, Philippe; Marin, Benoit; Fontaine, Sebastien; Boubaddi, Nour Edine; Clement, Marie-Pierre; Sautereau, Denis; Loustaud-Ratti, Veronique; Gourcerol, Guillaume; Monteil, Jacques

2018-06-12

 Gastroparesis is a functional disorder with a variety of symptoms that is characterized by delayed gastric emptying in the absence of mechanical obstruction. A recent series of retrospective studies has demonstrated that peroral endoscopic pyloromyotomy (G-POEM) is a promising endoscopic procedure for treating patients with refractory gastroparesis. The aim of this prospective study was to evaluate the feasibility, safety, and efficacy of G-POEM.  20 patients with refractory gastroparesis (10 diabetic and 10 nondiabetic) were prospectively included in the trial. Patients were treated by G-POEM after evaluation of pyloric function using an endoscopic functional luminal imaging probe. Clinical responses were evaluated using the Gastroparesis Cardinal Symptom Index (GCSI), and quality of life was assessed using the Patient Assessment of Upper Gastrointestinal Disorders - Quality of Life scale and the Gastrointestinal Quality of Life Index scores. Gastric emptying was measured using 4-hour scintigraphy before G-POEM and at 3 months.  Feasibility of the procedure was 100 %. Compared with baseline values, G-POEM significantly improved symptoms (GCSI: 1.3 vs. 3.5; P  < 0.001), quality of life, and gastric emptying (T½: 100 vs. 345 minutes, P  < 0.001; %H2: 56.0 % vs. 81.5 %, P  < 0.001; %H4: 15.0 % vs. 57.5 %, P  = 0.003) at 3 months. The clinical success of G-POEM using the functional imaging probe inflated to 50 mL had specificity of 100 % and sensitivity of 72.2 % ( P  = 0.04; 95 % confidence interval 0.51 - 0.94; area under the curve 0.72) at a distensibility threshold of 9.2 mm 2 /mmHg.  G-POEM was efficacious and safe for treating refractory gastroparesis, especially in patients with low pyloric distensibility. © Georg Thieme Verlag KG Stuttgart · New York.

Optical Coherence Microscopy

NASA Astrophysics Data System (ADS)

Aguirre, Aaron D.; Zhou, Chao; Lee, Hsiang-Chieh; Ahsen, Osman O.; Fujimoto, James G.

Cellular imaging of human tissues remains an important advance for many clinical applications of optical coherence tomography (OCT). Imaging cells with traditional OCT systems has not been possible due to the limited transverse resolution of such techniques. Optical coherence microscopy (OCM) refers to OCT methods that achieve high transverse resolution to visualize cells and subcellular features. This chapter provides a comprehensive discussion of the rationale for cellular imaging in human tissues as well as a review of the key technological advances required to achieve it. Time domain and Fourier domain OCM approaches are described with an emphasis on state of the art system designs, including miniaturized endoscopic imaging probes. Clinical applications are discussed and multiple examples of cellular imaging in human tissues are provided.

Design of signal reception and processing system of embedded ultrasonic endoscope

NASA Astrophysics Data System (ADS)

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.

Ultraminiature video-rate forward-view spectrally encoded endoscopy with straight axis configuration

NASA Astrophysics Data System (ADS)

Wang, Zhuo; Wu, Tzu-Yu; Hamm, Mark A.; Altshuler, Alexander; Mach, Anderson T.; Gilbody, Donald I.; Wu, Bin; Ganesan, Santosh N.; Chung, James P.; Ikuta, Mitsuhiro; Brauer, Jacob S.; Takeuchi, Seiji; Honda, Tokuyuki

2017-02-01

As one of the smallest endoscopes that have been demonstrated, the spectrally encoded endoscope (SEE) shows potential for the use in minimally invasive surgeries. While the original SEE is designed for side-view applications, the forwardview (FV) scope is more desired by physicians for many clinical applications because it provides a more natural navigation. Several FV SEEs have been designed in the past, which involve either multiple optical elements or one optical element with multiple optically active surfaces. Here we report a complete FV SEE which comprises a rotating illumination probe within a drive cable, a sheath and a window to cover the optics, a customized spectrometer, hardware controllers for both motor control and synchronization, and a software suite to capture, process and store images and videos. In this solution, the optical axis is straight and the dispersion element, i.e. the grating, is designed such that the slightly focused light after the focusing element will be dispersed by the grating, covering forward view angles with high diffraction efficiencies. As such, the illumination probe is fabricated with a diameter of only 275 μm. The twodimensional video-rate image acquisition is realized by rotating the illumination optics at 30 Hz. In one finished design, the scope diameter including the window assembly is 1.2 mm.

Multimodal 3D cancer-mimicking optical phantom

PubMed Central

Smith, Gennifer T.; Lurie, Kristen L.; Zlatev, Dimitar V.; Liao, Joseph C.; Ellerbee Bowden, Audrey K.

2016-01-01

Three-dimensional (3D) organ-mimicking phantoms provide realistic imaging environments for testing various aspects of optical systems, including for evaluating new probe designs, characterizing the diagnostic potential of new technologies, and assessing novel image processing algorithms prior to validation in real tissue. We introduce and characterize the use of a new material, Dragon Skin (Smooth-On Inc.), and fabrication technique, air-brushing, for fabrication of a 3D phantom that mimics the appearance of a real organ under multiple imaging modalities. We demonstrate the utility of the material and technique by fabricating the first 3D, hollow bladder phantom with realistic normal and multi-stage pathology features suitable for endoscopic detection using the gold standard imaging technique, white light cystoscopy (WLC), as well as the complementary imaging modalities of optical coherence tomography and blue light cystoscopy, which are aimed at improving the sensitivity and specificity of WLC to bladder cancer detection. The flexibility of the material and technique used for phantom construction allowed for the representation of a wide range of diseased tissue states, ranging from inflammation (benign) to high-grade cancerous lesions. Such phantoms can serve as important tools for trainee education and evaluation of new endoscopic instrumentation. PMID:26977369

Identification of early cancerous lesion of esophagus with endoscopic images by hyperspectral image technique (Conference Presentation)

NASA Astrophysics Data System (ADS)

Huang, Shih-Wei; Chen, Shih-Hua; Chen, Weichung; Wu, I.-Chen; Wu, Ming Tsang; Kuo, Chie-Tong; Wang, Hsiang-Chen

2016-03-01

This study presents a method to identify early esophageal cancer within endoscope using hyperspectral imaging technology. The research samples are three kinds of endoscopic images including white light endoscopic, chromoendoscopic, and narrow-band endoscopic images with different stages of pathological changes (normal, dysplasia, dysplasia - esophageal cancer, and esophageal cancer). Research is divided into two parts: first, we analysis the reflectance spectra of endoscopic images with different stages to know the spectral responses by pathological changes. Second, we identified early cancerous lesion of esophagus by principal component analysis (PCA) of the reflectance spectra of endoscopic images. The results of this study show that the identification of early cancerous lesion is possible achieve from three kinds of images. In which the spectral characteristics of NBI endoscopy images of a gray area than those without the existence of the problem the first two, and the trend is very clear. Therefore, if simply to reflect differences in the degree of spectral identification, chromoendoscopic images are suitable samples. The best identification of early esophageal cancer is using the NBI endoscopic images. Based on the results, the use of hyperspectral imaging technology in the early endoscopic esophageal cancer lesion image recognition helps clinicians quickly diagnose. We hope for the future to have a relatively large amount of endoscopic image by establishing a hyperspectral imaging database system developed in this study, so the clinician can take this repository more efficiently preliminary diagnosis.

Feasibility of Newly Developed Endoscopic Ultrasound with Zone Sonography Technology for Diagnosis of Pancreatic Diseases

PubMed Central

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

2013-01-01

Background/Aims To confirm the feasibility of using newly developed endoscopic ultrasound (EUS) with Zone sonography™ technology (ZST; Fujifilm Corp.). Methods Seventy-five patients with pancreatic disorders were enrolled: 45 with intraductal papillary mucinous neoplasm; 15 with ductal carcinoma; five with neuroendocrine tumors; three with serous cystic neoplasms; and seven with simple cysts. The endoscopes used were EG-530UR2 and EG-530UT2 (Fujifilm Corp.). Two items were evaluated: visualization depth among four frequencies and image quality after automatic adjustment of sound speed (AASS), assessed using a 5-scale Likert scale by two endosonographers blinded to disease status. Because sound speed could be manually controlled, besides AASS, image quality at sound speeds of 1,440 and 1,600 m/sec were also assessed. Results In all cases, sufficient images were obtained in the range of 3 cm from the EUS probe. Judgments of image quality before AASS were 3.49±0.50, 3.65±0.48, respectively. After AASS, A and B scored 4.36±0.48 and 4.40±0.49 (p<0.0001). There were significant differences in the data before and after AASS and plus 60 m/sec, but no significant difference between the datasets were seen after AASS and at sound speeds manually set for minus 100 m/sec. Conclusions EUS with ZST was shown to be feasible in this preliminary experiment. Further evaluation of this novel technology is necessary and awaited. PMID:23898392

Feasibility of newly developed endoscopic ultrasound with zone sonography technology for diagnosis of pancreatic diseases.

PubMed

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

2013-07-01

To confirm the feasibility of using newly developed endoscopic ultrasound (EUS) with Zone sonography™ technology (ZST; Fujifilm Corp.). Seventy-five patients with pancreatic disorders were enrolled: 45 with intraductal papillary mucinous neoplasm; 15 with ductal carcinoma; five with neuroendocrine tumors; three with serous cystic neoplasms; and seven with simple cysts. The endoscopes used were EG-530UR2 and EG-530UT2 (Fujifilm Corp.). Two items were evaluated: visualization depth among four frequencies and image quality after automatic adjustment of sound speed (AASS), assessed using a 5-scale Likert scale by two endosonographers blinded to disease status. Because sound speed could be manually controlled, besides AASS, image quality at sound speeds of 1,440 and 1,600 m/sec were also assessed. In all cases, sufficient images were obtained in the range of 3 cm from the EUS probe. Judgments of image quality before AASS were 3.49±0.50, 3.65±0.48, respectively. After AASS, A and B scored 4.36±0.48 and 4.40±0.49 (p<0.0001). There were significant differences in the data before and after AASS and plus 60 m/sec, but no significant difference between the datasets were seen after AASS and at sound speeds manually set for minus 100 m/sec. EUS with ZST was shown to be feasible in this preliminary experiment. Further evaluation of this novel technology is necessary and awaited.

Fluorescence and Spectral Imaging

PubMed Central

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

2007-01-01

Early identification of dysplasia remains a critical goal for diagnostic endoscopy since early discovery directly improves patient survival because it allows endoscopic or surgical intervention with disease localized without lymph node involvement. Clinical studies have successfully used tissue autofluorescence with conventional white light endoscopy and biopsy for detecting adenomatous colonic polyps, differentiating benign hyperplastic from adenomas with acceptable sensitivity and specificity. In Barrett's esophagus, the detection of dysplasia remains problematic because of background inflammation, whereas in the squamous esophagus, autofluorescence imaging appears to be more dependable. Point fluorescence spectroscopy, although playing a crucial role in the pioneering mechanistic development of fluorescence endoscopic imaging, does not seem to have a current function in endoscopy because of its nontargeted sampling and suboptimal sensitivity and specificity. Other point spectroscopic modalities, such as Raman spectroscopy and elastic light scattering, continue to be evaluated in clinical studies, but still suffer the significant disadvantages of being random and nonimaging. A recent addition to the fluorescence endoscopic imaging arsenal is the use of confocal fluorescence endomicroscopy, which provides real-time optical biopsy for the first time. To improve detection of dysplasia in the gastrointestinal tract, a new and exciting development has been the use of exogenous fluorescence contrast probes that specifically target a variety of disease-related cellular biomarkers using conventional fluorescent dyes and novel potent fluorescent nanocrystals (i.e., quantum dots). This is an area of great promise, but still in its infancy, and preclinical studies are currently under way. PMID:18167619

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

PubMed

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.

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

PubMed Central

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.

2013-01-01

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. PMID:23847737

Monte Carlo analysis on probe performance for endoscopic diffuse optical spectroscopy of tubular organ

NASA Astrophysics Data System (ADS)

Zhang, Yunyao; Zhu, Jingping; Cui, Weiwen; Nie, Wei; Li, Jie; Xu, Zhenghong

2015-03-01

We investigated the performance of endoscopic diffuse optical spectroscopy probes with circular or linear fiber arrangements for tubular organ cancer detection. Probe performance was measured by penetration depth. A Monte Carlo model was employed to simulate light transport in the hollow cylinder that both emits and receives light from the inner boundary of the sample. The influence of fiber configurations and tissue optical properties on penetration depth was simulated. The results show that under the same condition, probes with circular fiber arrangement penetrate deeper than probes with linear fiber arrangement, and the difference between the two probes' penetration depth decreases with an increase in the 'distance between source and detector (SD)' and the radius of the probe. Other results show that the penetration depths and their differences both decrease with an increase in the absorption coefficient and the reduced scattering coefficient but remain constant with changes in the anisotropy factor. Moreover, the penetration depth was more affected by the absorption coefficient than the reduced scattering coefficient. It turns out that in NIR band, probes with linear fiber arrangements are more appropriate for diagnosing superficial cancers, whereas probes with circular fiber arrangements should be chosen for diagnosing adenocarcinoma. But in UV-VIS band, the two probe configurations exhibit nearly the same. These results are useful in guiding endoscopic diffuse optical spectroscopy-based diagnosis for esophageal, cervical, colorectal and other cancers.

Development of an endoscopic fluorescence image-guided OCT probe for oral cancer detection

NASA Astrophysics Data System (ADS)

McNichols, Roger J.; Gowda, Ashok; Bell, Brent A.; Johnigan, Richard M.; Calhoun, Karen H.; Motamedi, Massoud

2001-06-01

Oral squamous cell carcinoma is a disease which progresses through a number of well-defined morphological and biochemical changes. Optical coherence tomography (OCT) is a rapidly-evolving, non-invasive imaging modality which allows detailed probing of subsurface tissue structures with resolution on the order of microns. While this technique offers tremendous potential as a diagnostic tool for detection and characterization of oral cancer, OCT imaging is presently associated with a field of view on the order of millimeters, and acquisition time on the order of seconds. Thus, OCT's utility as a rapid cancer screening technique is presently limited. On the other hand, imaging of tissue autofluorescence provides a very rapid, high-throughput method for cancer screening. However, while autofluorescence measures may be sensitive to cancer, they are often non- specific and lead to a large number of false positives. In the present work, we have developed a fluorescence image guided optical coherence tomographic (FIG-OCT) probe in which tissue autofluorescence images are simultaneously used to guide OCT image acquisition of suspicious regions in real time. We have begun pre-clinical pilot studies with this instrument in a DMBA-induced model of oral cancer in the hamster cheek pouch. Initial results indicate that the FIG- OCT approach shows promise as a rapid and effective tool for screening of oral cancer.

In Vivo Biomarkers for Targeting Colorectal Neoplasms

PubMed Central

Hsiung, Pei-Lin; Wang, Thomas

2011-01-01

Summary Colorectal carcinoma continues to be a leading cause of cancer morbidity and mortality despite widespread adoption of screening methods. Targeted detection and therapy using recent advances in our knowledge of in vivo cancer biomarkers promise to significantly improve methods for early detection, risk stratification, and therapeutic intervention. The behavior of molecular targets in transformed tissues is being comprehensively assessed using new techniques of gene expression profiling and high throughput analyses. The identification of promising targets is stimulating the development of novel molecular probes, including significant progress in the field of activatable and peptide probes. These probes are being evaluated in small animal models of colorectal neoplasia and recently in the clinic. Furthermore, innovations in optical imaging instrumentation are resulting in the scaling down of size for endoscope compatibility. Advances in target identification, probe development, and novel instruments are progressing rapidly, and the integration of these technologies has a promising future in molecular medicine. PMID:19126961

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

NASA Astrophysics Data System (ADS)

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.

Endoscopic add-on stiffness probe for real-time soft surface characterisation in MIS.

PubMed

Faragasso, A; Stilli, A; Bimbo, J; Noh, Y; Liu, H; Nanayakkara, T; Dasgupta, P; Wurdemann, H A; Althoefer, K

2014-01-01

This paper explores a novel stiffness sensor which is mounted on the tip of a laparoscopic camera. The proposed device is able to compute stiffness when interacting with soft surfaces. The sensor can be used in Minimally Invasive Surgery, for instance, to localise tumor tissue which commonly has a higher stiffness when compared to healthy tissue. The purely mechanical sensor structure utilizes the functionality of an endoscopic camera to the maximum by visually analyzing the behavior of trackers within the field of view. Two pairs of spheres (used as easily identifiable features in the camera images) are connected to two springs with known but different spring constants. Four individual indenters attached to the spheres are used to palpate the surface. During palpation, the spheres move linearly towards the objective lens (i.e. the distance between lens and spheres is changing) resulting in variations of their diameters in the camera images. Relating the measured diameters to the different spring constants, a developed mathematical model is able to determine the surface stiffness in real-time. Tests were performed using a surgical endoscope to palpate silicon phantoms presenting different stiffness. Results show that the accuracy of the sensing system developed increases with the softness of the examined tissue.

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

PubMed

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 < .005) and a 69% loss in the open procedure group (mean preoperative LESp, 24.2 ± 3.2 mm Hg; mean postoperative LESp, 7.4 ± 4 mm Hg; P < .005). The EndoFLIP monitoring did not show any distensibility difference between the 2 techniques, with the main improvement occurring when the clasp circular fibers were taken. Healthy animal model; small sample. Endoscopic submucosal esophageal 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.

Extraction of endoscopic images for biomedical figure classification

NASA Astrophysics Data System (ADS)

Xue, Zhiyun; You, Daekeun; Chachra, Suchet; Antani, Sameer; Long, L. R.; Demner-Fushman, Dina; Thoma, George R.

2015-03-01

Modality filtering is an important feature in biomedical image searching systems and may significantly improve the retrieval performance of the system. This paper presents a new method for extracting endoscopic image figures from photograph images in biomedical literature, which are found to have highly diverse content and large variability in appearance. Our proposed method consists of three main stages: tissue image extraction, endoscopic image candidate extraction, and ophthalmic image filtering. For tissue image extraction we use image patch level clustering and MRF relabeling to detect images containing skin/tissue regions. Next, we find candidate endoscopic images by exploiting the round shape characteristics that commonly appear in these images. However, this step needs to compensate for images where endoscopic regions are not entirely round. In the third step we filter out the ophthalmic images which have shape characteristics very similar to the endoscopic images. We do this by using text information, specifically, anatomy terms, extracted from the figure caption. We tested and evaluated our method on a dataset of 115,370 photograph figures, and achieved promising precision and recall rates of 87% and 84%, respectively.

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

PubMed Central

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 leakage. The accuracy of the measurements was 1.20 + 0.21 mm (mean +/−SD). Conclusion Image-based pre-operative vascular and neural element segmentation, especially with 3D reconstruction, is highly informative preoperatively and potentially could assist less experienced neurosurgeons in preventing vascular and neural injury during TSS. Additionally, the accuracy found in this study is comparable to previously reported neuronavigation measurements. This novel preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients. PMID:27302558

Contrast-enhanced endoscopic ultrasonography in digestive diseases.

PubMed

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.

In Vivo Cancer Biomarkers of Esophageal Neoplasia

PubMed Central

Lu, Shaoying; Wang, Thomas D

2011-01-01

Summary The emergence of in vivo cancer biomarkers is promising tool for early detection, risk stratification, and therapeutic intervention in the esophagus, where adenocarcinoma is increasing at a rate that is faster than any other in industrialized nations. Exciting advances in target identification, probe development, and optical instrumentation are creating tremendous new opportunities for advancing techniques of molecular imaging. Progress in these areas is being made with small animal models of esophageal cancer using surgical approaches to induce reflux of acid and bile, and these findings are beginning to be evaluated in the clinic. Further identification of relevant targets, characterization of specific probes, and development of endoscopic imaging technologies are needed to further this direction in the field of molecular medicine. In the future, new methods that use in vivo cancer biomarkers for the early detection of neoplastic changes in the setting of Barrett's esophagus will become available. PMID:19126962

Quantitative endoscopy: initial accuracy measurements.

PubMed

Truitt, T O; Adelman, R A; Kelly, D H; Willging, J P

2000-02-01

The geometric optics of an endoscope can be used to determine the absolute size of an object in an endoscopic field without knowing the actual distance from the object. This study explores the accuracy of a technique that estimates absolute object size from endoscopic images. Quantitative endoscopy involves calibrating a rigid endoscope to produce size estimates from 2 images taken with a known traveled distance between the images. The heights of 12 samples, ranging in size from 0.78 to 11.80 mm, were estimated with this calibrated endoscope. Backup distances of 5 mm and 10 mm were used for comparison. The mean percent error for all estimated measurements when compared with the actual object sizes was 1.12%. The mean errors for 5-mm and 10-mm backup distances were 0.76% and 1.65%, respectively. The mean errors for objects <2 mm and > or =2 mm were 0.94% and 1.18%, respectively. Quantitative endoscopy estimates endoscopic image size to within 5% of the actual object size. This method remains promising for quantitatively evaluating object size from endoscopic images. It does not require knowledge of the absolute distance of the endoscope from the object, rather, only the distance traveled by the endoscope between images.

Subjective pain perception during calculus detection with use of a periodontal endoscope.

PubMed

Poppe, Kjersta; Blue, Christine

2014-04-01

Periodontal endoscopes are relatively new to the dental field. The purpose of this study was to determine the amount of pain reported by subjects with periodontal disease after experiencing the use of a periodontal endoscope compared with the use of a periodontal probe during calculus detection. A total of 30 subjects with at least 4 sites of 5 to 8 mm pocket depths were treated with scaling and root planing therapy in a split-mouth design. The 2 quadrants were randomly assigned to either S/RP with tactile determination of calculus using an 11/12 explorer, or S/RP treatment with endoscopic detection of calculus. Each subject's pain experience was determined by via a Heft-Parker Visual Analogue Scale (VAS), which measured perceived pain level during periodontal probing and during subgingival visualization via endoscopy. Since subjects expressing some level of dental anxiety generally express increased levels of pain, a pre-treatment survey was also given to determine each subject's level of dental anxiety in order to eliminate dental anxiety as a confounding factor in determining the expressed level of pain. The level of perceived pain was significantly lower with the periodontal endoscope versus the probe (mean VAS 33.0 mm versus 60.2 mm, p<0.0001). Subjects who indicated some level of dental anxiety did express increased pain levels, but these levels were not statistically significant. Subjects did not find the periodontal endoscope to elicit significant anxiety or pain during subgingival visualization.

Advanced endoscopic imaging to improve adenoma detection

PubMed Central

Neumann, Helmut; Nägel, Andreas; Buda, Andrea

2015-01-01

Advanced endoscopic imaging is revolutionizing our way on how to diagnose and treat colorectal lesions. Within recent years a variety of modern endoscopic imaging techniques was introduced to improve adenoma detection rates. Those include high-definition imaging, dye-less chromoendoscopy techniques and novel, highly flexible endoscopes, some of them equipped with balloons or multiple lenses in order to improve adenoma detection rates. In this review we will focus on the newest developments in the field of colonoscopic imaging to improve adenoma detection rates. Described techniques include high-definition imaging, optical chromoendoscopy techniques, virtual chromoendoscopy techniques, the Third Eye Retroscope and other retroviewing devices, the G-EYE endoscope and the Full Spectrum Endoscopy-system. PMID:25789092

Endoscopic measurements using a panoramic annular lens

NASA Technical Reports Server (NTRS)

Gilbert, John A.; Matthys, Donald R.

1992-01-01

The objective of this project was to design, build, demonstrate, and deliver a prototype system for making measurements within cavities. The system was to utilize structured lighting as the means for making measurements and was to rely on a stationary probe, equipped with a unique panoramic annular lens, to capture a cylindrical view of the illuminated cavity. Panoramic images, acquired with a digitizing camera and stored in a desk top computer, were to be linearized and analyzed by mouse-driven interactive software.

Doppler Endoscopic Probe Monitoring of Blood Flow Improves Risk Stratification and Outcomes of Patients With Severe Nonvariceal Upper Gastrointestinal Hemorrhage.

PubMed

Jensen, Dennis M; Kovacs, Thomas O G; Ohning, Gordon V; Ghassemi, Kevin; Machicado, Gustavo A; Dulai, Gareth S; Sedarat, Alireza; Jutabha, Rome; Gornbein, Jeffrey

2017-05-01

For 4 decades, stigmata of recent hemorrhage in patients with nonvariceal lesions have been used for risk stratification and endoscopic hemostasis. The arterial blood flow that underlies the stigmata rarely is monitored, but can be used to determine risk for rebleeding. We performed a randomized controlled trial to determine whether Doppler endoscopic probe monitoring of blood flow improves risk stratification and outcomes in patients with severe nonvariceal upper gastrointestinal hemorrhage. In a single-blind study performed at 2 referral centers we assigned 148 patients with severe nonvariceal upper gastrointestinal bleeding (125 with ulcers, 19 with Dieulafoy's lesions, and 4 with Mallory Weiss tears) to groups that underwent standard, visually guided endoscopic hemostasis (control, n = 76), or endoscopic hemostasis assisted by Doppler monitoring of blood flow under the stigmata (n = 72). The primary outcome was the rate of rebleeding after 30 days; secondary outcomes were complications, death, and need for transfusions, surgery, or angiography. There was a significant difference in the rates of lesion rebleeding within 30 days of endoscopic hemostasis in the control group (26.3%) vs the Doppler group (11.1%) (P = .0214). The odds ratio for rebleeding with Doppler monitoring was 0.35 (95% confidence interval, 0.143-0.8565) and the number needed to treat was 7. In a randomized controlled trial of patients with severe upper gastrointestinal hemorrhage from ulcers or other lesions, Doppler probe guided endoscopic hemostasis significantly reduced 30-day rates of rebleeding compared with standard, visually guided hemostasis. Guidelines for nonvariceal gastrointestinal bleeding should incorporate these results. ClinicalTrials.gov no: NCT00732212 (CLIN-013-07F). Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Fatal air embolism during endoscopic retrograde cholangiopancreatography (ERCP): An 'impossible' diagnosis for the forensic pathologist.

PubMed

Marchesi, Matteo; Battistini, Alessio; Pellegrinelli, Moira; Gentile, Guendalina; Zoja, Riccardo

2016-01-01

Fatal air embolism related to endoscopic retrograde cholangiopancreatography is a very rare phenomenon. The authors describe the case of a 51-year-old female patient who developed this mortal complication; a computed tomography (CT) examination was performed in articulo mortis by the physicians. Autopsy was unreliable because of bizarre post-mortem changes (reabsorption of intra-cardiac gas vs. conservation of intra-cranial gas) and a lack of strong diagnostic value of histological findings. The right diagnosis was possible thanks only to the CT examination that permitted the assumption of this possible cause of death before the autopsy and to prepare the necessary procedures to recognise and probe air embolism. This case exemplifies how early post-mortem imaging can be crucial to avoid a wrong diagnosis. © The Author(s) 2015.

Advanced endoscopic imaging: European Society of Gastrointestinal Endoscopy (ESGE) Technology Review.

PubMed

East, James E; Vleugels, Jasper L; Roelandt, Philip; Bhandari, Pradeep; Bisschops, Raf; Dekker, Evelien; Hassan, Cesare; Horgan, Gareth; Kiesslich, Ralf; Longcroft-Wheaton, Gaius; Wilson, Ana; Dumonceau, Jean-Marc

2016-11-01

Background and aim: This technical review is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). It addresses the utilization of advanced endoscopic imaging in gastrointestinal (GI) endoscopy. Methods: This technical review is based on a systematic literature search to evaluate the evidence supporting the use of advanced endoscopic imaging throughout the GI tract. Technologies considered include narrowed-spectrum endoscopy (narrow band imaging [NBI]; flexible spectral imaging color enhancement [FICE]; i-Scan digital contrast [I-SCAN]), autofluorescence imaging (AFI), and confocal laser endomicroscopy (CLE). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendation and the quality of evidence. Main recommendations: 1. We suggest advanced endoscopic imaging technologies improve mucosal visualization and enhance fine structural and microvascular detail. Expert endoscopic diagnosis may be improved by advanced imaging, but as yet in community-based practice no technology has been shown consistently to be diagnostically superior to current practice with high definition white light. (Low quality evidence.) 2. We recommend the use of validated classification systems to support the use of optical diagnosis with advanced endoscopic imaging in the upper and lower GI tracts (strong recommendation, moderate quality evidence). 3. We suggest that training improves performance in the use of advanced endoscopic imaging techniques and that it is a prerequisite for use in clinical practice. A learning curve exists and training alone does not guarantee sustained high performances in clinical practice. (Weak recommendation, low quality evidence.) Conclusion: Advanced endoscopic imaging can improve mucosal visualization and endoscopic diagnosis; however it requires training and the use of validated classification systems. © Georg Thieme Verlag KG Stuttgart · New York.

Analysis of the color rendition of flexible endoscopes

NASA Astrophysics Data System (ADS)

Murphy, Edward M.; Hegarty, Francis J.; McMahon, Barry P.; Boyle, Gerard

2003-03-01

Endoscopes are imaging devices routinely used for the diagnosis of disease within the human digestive tract. Light is transmitted into the body cavity via incoherent fibreoptic bundles and is controlled by a light feedback system. Fibreoptic endoscopes use coherent fibreoptic bundles to provide the clinician with an image. It is also possible to couple fibreoptic endoscopes to a clip-on video camera. Video endoscopes consist of a small CCD camera, which is inserted into gastrointestinal tract, and associated image processor to convert the signal to analogue RGB video signals. Images from both types of endoscope are displayed on standard video monitors. Diagnosis is dependent upon being able to determine changes in the structure and colour of tissues and biological fluids, and therefore is dependent upon the ability of the endoscope to reproduce the colour of these tissues and fluids with fidelity. This study investigates the colour reproduction of flexible optical and video endoscopes. Fibreoptic and video endoscopes alter image colour characteristics in different ways. The colour rendition of fibreoptic endoscopes was assessed by coupling them to a video camera and applying video colorimetric techniques. These techniques were then used on video endoscopes to assess how the colour rendition of video endoscopes compared with that of optical endoscopes. In both cases results were obtained at fixed illumination settings. Video endoscopes were then assessed with varying levels of illumination. Initial results show that at constant luminance endoscopy systems introduce non-linear shifts in colour. Techniques for examining how this colour shift varies with illumination intensity were developed and both methodology and results will be presented. We conclude that more rigorous quality assurance is required to reduce colour error and are developing calibration procedures applicable to medical endoscopes.

A wireless narrowband imaging chip for capsule endoscope.

PubMed

Lan-Rong Dung; Yin-Yi Wu

2010-12-01

This paper presents a dual-mode capsule gastrointestinal endoscope device. An endoscope combined with a narrowband image (NBI), has been shown to be a superior diagnostic tool for early stage tissue neoplasms detection. Nevertheless, a wireless capsule endoscope with the narrowband imaging technology has not been presented in the market up to now. The narrowband image acquisition and power dissipation reduction are the main challenges of NBI capsule endoscope. In this paper, we present the first narrowband imaging capsule endoscope that can assist clinical doctors to effectively diagnose early gastrointestinal cancers, profited from our dedicated dual-mode complementary metal-oxide semiconductor (CMOS) sensor. The dedicated dual-mode CMOS sensor can offer white-light and narrowband images. Implementation results show that the proposed 512 × 512 CMOS sensor consumes only 2 mA at a 3-V power supply. The average current of the NBI capsule with an 8-Mb/s RF transmitter is nearly 7 ~ 8 mA that can continuously work for 6 ~ 8 h with two 1.5-V 80-mAh button batteries while the frame rate is 2 fps. Experimental results on backside mucosa of a human tongue and pig's small intestine showed that the wireless NBI capsule endoscope can significantly improve the image quality, compared with a commercial-of-the-shelf capsule endoscope for gastrointestinal tract diagnosis.

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

PubMed

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.

Design of a handheld optical coherence microscopy endoscope

NASA Astrophysics Data System (ADS)

Korde, Vrushali R.; Liebmann, Erica; Barton, Jennifer K.

2011-06-01

Optical coherence microscopy (OCM) combines coherence gating, high numerical aperture optics, and a fiber-core pinhole to provide high axial and lateral resolution with relatively large depth of imaging. We present a handheld rigid OCM endoscope designed for small animal surgical imaging, with a 6-mm diam tip, 1-mm scan width, and 1-mm imaging depth. X-Y scanning is performed distally with mirrors mounted to micro galvonometer scanners incorporated into the endoscope handle. The endoscope optical design consists of scanning doublets, an afocal Hopkins relay lens system, a 0.4 numerical aperture water immersion objective, and a cover glass. This endoscope can resolve laterally a 1.4-μm line pair feature and has an axial resolution (full width half maximum) of 5.4 μm. Images taken with this endoscope of fresh ex-vivo mouse ovaries show structural features, such as corpus luteum, primary follicles, growing follicles, and fallopian tubes. This rigid handheld OCM endoscope can be useful for a variety of minimally invasive and surgical imaging applications.

The Clinical Accuracy of Endoscopic Ultrasonography and White Light Imaging in Gastric Endoscopic Submucosal Dissection

PubMed Central

Park, Soon Hong; Sung, Sang Hun; Lee, Seung Jun; Jung, Min Kyu; Kim, Sung Kook

2012-01-01

Purpose Gastric mucosal neoplastic lesions should have characteristic endoscopic features for successful endoscopic submucosal dissection. Materials and Methods Out of the 1,010 endoscopic submucosal dissection, we enrolled 62 patients that had the procedure cancelled. Retrospectively, whether the reasons for cancelling the endoscopic submucosal dissection were consistent with the indications for an endoscopic submucosal dissection were assessed by analyzing the clinical outcomes of the patients that had the surgery. Results The cases were divided into two groups; the under-diagnosed group (30 cases; unable to perform an endoscopic submucosal dissection) and the over-diagnosed group (32 cases; unnecessary to perform an endoscopic submucosal dissection), according to the second endoscopic findings, compared with the index conventional white light image. There were six cases in the under-diagnosed group with advanced gastric cancer on the second conventional white light image endoscopy, 17 cases with submucosal invasion on endoscopic ultrasonography findings, 5 cases with a size greater than 3 cm and ulcer, 1 case with diffuse infiltrative endoscopic features, and 1 case with lymph node involvement on computed tomography. A total of 25 patients underwent a gastrectomy to remove a gastric adenocarcinoma. The overall accuracy of the decision to cancel the endoscopic submucosal dissection was 40% (10/25) in the subgroup that had the surgery. Conclusions The accuracy of the decision to cancel the endoscopic submucosal dissection, after conventional white light image and endoscopic ultrasonography, was low in this study. Other diagnostic options are needed to arrive at an accurate decision on whether to perform a gastric endoscopic submucosal dissection. PMID:22792522

Fluorescence multi-scale endoscopy and its applications in the study and diagnosis of gastro-intestinal diseases: set-up design and software implementation

NASA Astrophysics Data System (ADS)

Gómez-García, Pablo Aurelio; Arranz, Alicia; Fresno, Manuel; Desco, Manuel; Mahmood, Umar; Vaquero, Juan José; Ripoll, Jorge

2015-06-01

Endoscopy is frequently used in the diagnosis of several gastro-intestinal pathologies as Crohn disease, ulcerative colitis or colorectal cancer. It has great potential as a non-invasive screening technique capable of detecting suspicious alterations in the intestinal mucosa, such as inflammatory processes. However, these early lesions usually cannot be detected with conventional endoscopes, due to lack of cellular detail and the absence of specific markers. Due to this lack of specificity, the development of new endoscopy technologies, which are able to show microscopic changes in the mucosa structure, are necessary. We here present a confocal endomicroscope, which in combination with a wide field fluorescence endoscope offers fast and specific macroscopic information through the use of activatable probes and a detailed analysis at cellular level of the possible altered tissue areas. This multi-modal and multi-scale imaging module, compatible with commercial endoscopes, combines near-infrared fluorescence (NIRF) measurements (enabling specific imaging of markers of disease and prognosis) and confocal endomicroscopy making use of a fiber bundle, providing a cellular level resolution. The system will be used in animal models exhibiting gastro-intestinal diseases in order to analyze the use of potential diagnostic markers in colorectal cancer. In this work, we present in detail the set-up design and the software implementation in order to obtain simultaneous RGB/NIRF measurements and short confocal scanning times.

Design of a modified endoscope illuminator for spectral imaging of colorectal tissues

NASA Astrophysics Data System (ADS)

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

2017-02-01

The gold standard for locating colonic polyps is a white light endoscope in a colonoscopy, however, polyps smaller than 5 mm can be easily missed. Modified procedures such as narrow band imaging have shown only marginal increases in detection rates. Spectral imaging is a potential solution to improve the sensitivity and specificity of colonoscopies by providing the ability to distinguish molecular fluorescence differences in tissues. The goal of this work is to implement a spectral endoscopic light source to acquire spectral image data of colorectal tissues. A beta-version endoscope light source was developed, by retrofitting a white light endoscope light source (Olympus, CLK-4) with 16 narrow band LEDs. This redesigned, beta-prototype uses high-power LEDs with a minimum output of 500 mW to provide sufficient spectral output (0.5 mW) through the endoscope. A mounting apparatus was designed to provide sufficient heat dissipation. Here, we report recent results of our tests to characterize the intensity output through the light source and endoscope to determine the flat spectral output for imaging and intensity losses through the endoscope. We also report preliminary spectral imaging data from transverse pig colon that demonstrates the ability to result in working practical spectral data. Preliminary results of this revised prototype spectral endoscope system demonstrate that there is sufficient power to allow the imaging process to continue and potentially determine spectral differences in cancerous and normal tissue from imaging ex vivo pairs. Future work will focus on building a spectral library for the colorectal region and refining the user interface the system for in vivo use.

[Experience of Fusion image guided system in endonasal endoscopic surgery].

PubMed

Wen, Jingying; Zhen, Hongtao; Shi, Lili; Cao, Pingping; Cui, Yonghua

2015-08-01

To review endonasal endoscopic surgeries aided by Fusion image guided system, and to explore the application value of Fusion image guided system in endonasal endoscopic surgeries. Retrospective research. Sixty cases of endonasal endoscopic surgeries aided by Fusion image guided system were analysed including chronic rhinosinusitis with polyp (n = 10), fungus sinusitis (n = 5), endoscopic optic nerve decompression (n = 16), inverted papilloma of the paranasal sinus (n = 9), ossifying fibroma of sphenoid bone (n = 1), malignance of the paranasal sinus (n = 9), cerebrospinal fluid leak (n = 5), hemangioma of orbital apex (n = 2) and orbital reconstruction (n = 3). Sixty cases of endonasal endoscopic surgeries completed successfully without any complications. Fusion image guided system can help to identify the ostium of paranasal sinus, lamina papyracea and skull base. Fused CT-CTA images, or fused MR-MRA images can help to localize the optic nerve or internal carotid arteiy . Fused CT-MR images can help to detect the range of the tumor. It spent (7.13 ± 1.358) minutes for image guided system to do preoperative preparation and the surgical navigation accuracy reached less than 1mm after proficient. There was no device localization problem because of block or head set loosed. Fusion image guided system make endonasal endoscopic surgery to be a true microinvasive and exact surgery. It spends less preoperative preparation time, has high surgical navigation accuracy, improves the surgical safety and reduces the surgical complications.

Endoscopic Sex Identification in Chelonians and Birds (Psittacines, Passerines, and Raptors).

PubMed

Divers, Stephen J

2015-09-01

Despite the advent of DNA probes for sex identification of many avian and some reptile species, clinicians involved with zoos, conservation projects, or breeders may still be asked to perform "surgical sexing." This article describes the practical approach to performing endoscopic sex identification in psittacines and chelonians, including patient preparation, anesthesia, and endoscopic procedure. Copyright © 2015 Elsevier Inc. All rights reserved.

Endoscopes with latest technology and concept.

PubMed

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.

Evaluation of endoscopic entire 3D image acquisition of the digestive tract using a stereo endoscope

NASA Astrophysics Data System (ADS)

Yoshimoto, Kayo; Watabe, Kenji; Fujinaga, Tetsuji; Iijima, Hideki; Tsujii, Masahiko; Takahashi, Hideya; Takehara, Tetsuo; Yamada, Kenji

2017-02-01

Because the view angle of the endoscope is narrow, it is difficult to get the whole image of the digestive tract at once. If there are more than two lesions in the digestive tract, it is hard to understand the 3D positional relationship among the lesions. Virtual endoscopy using CT is a present standard method to get the whole view of the digestive tract. Because the virtual endoscopy is designed to detect the irregularity of the surface, it cannot detect lesions that lack irregularity including early cancer. In this study, we propose a method of endoscopic entire 3D image acquisition of the digestive tract using a stereo endoscope. The method is as follows: 1) capture sequential images of the digestive tract by moving the endoscope, 2) reconstruct 3D surface pattern for each frame by stereo images, 3) estimate the position of the endoscope by image analysis, 4) reconstitute the entire image of the digestive tract by combining the 3D surface pattern. To confirm the validity of this method, we experimented with a straight tube inside of which circles were allocated at equal distance of 20 mm. We captured sequential images and the reconstituted image of the tube revealed that the distance between each circle was 20.2 +/- 0.3 mm (n=7). The results suggest that this method of endoscopic entire 3D image acquisition may help us understand 3D positional relationship among the lesions such as early esophageal cancer that cannot be detected by virtual endoscopy using CT.

The endoscopic diagnosis of nonerosive reflux disease using flexible spectral imaging color enhancement image: a feasibility trial.

PubMed

Miyasaka, M; Hirakawa, M; Nakamura, K; Tanaka, F; Mimori, K; Mori, M; Honda, H

2011-08-01

Nonerosive reflux disease (NERD) is classified into grade M (minimal change, endoscopically; erythema without sharp demarcation, whitish turbidity, and/or invisibility of vessels due to these findings) and grade N (normal) in the modified Los Angeles classification system in Japan. However, the classification of grades M and N NERD is not included in the original Los Angeles system because interobserver agreement for the conventional endoscopic diagnosis of grades M or N NERD is poor. Flexible spectral imaging color enhancement (FICE) is a virtual chromoendoscopy technique that enhances mucosal and vascular visibility. The aim of this study is to evaluate whether the endoscopic diagnosis of grades M or N NERD using FICE images is feasible. Between April 2006 and May 2008, 26 NERD patients and 31 controls were enrolled in the present study. First, an experienced endoscopist assessed the color pattern of minimal change in FICE images using conventional endoscopic images and FICE images side-by-side and comparing the proportion of minimal change between the two groups. Second, three blinded endoscopists assessed the presence or absence of minimal change in both groups using conventional endoscopic images and FICE images separately. Intraobserver variability was compared using McNemar's test, and interobserver agreement was described using the kappa value. Minimal changes, such as erythema and whitish turbidity, which were detected using conventional endoscopic images, showed up as navy blue and pink-white, respectively, in color using FICE images in the present FICE mode. The NERD group had a higher proportion of minimal change, compared with the control group (77% and 48%, respectively) (P= 0.033). In all three readers, the detection rates of minimal change using FICE images were greater than those using conventional endoscopic images (P= 0.025, <0.0001, and 0.034 for readers A, B, and C, respectively). The kappa values for all pairs of three readers using FICE images were between 0.683 and 0.812, while those using conventional endoscopic images were between 0.364 and 0.624. Thus, the endoscopic diagnosis of grades M or N NERD using FICE images is feasible and may improve interobserver agreement. © 2011 Copyright the Authors. Journal compilation © 2011, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

Real-time ultrasound-guided endoscopic surgery for putaminal hemorrhage.

PubMed

Sadahiro, Hirokazu; Nomura, Sadahiro; Goto, Hisaharu; Sugimoto, Kazutaka; Inamura, Akinori; Fujiyama, Yuichi; Yamane, Akiko; Oku, Takayuki; Shinoyama, Mizuya; Suzuki, Michiyasu

2015-11-01

Endoscopic surgery plays a significant role in the treatment of intracerebral hemorrhage. However, the residual hematoma cannot be measured intraoperatively from the endoscopic view, and it is difficult to determine the precise location of the endoscope within the hematoma cavity. The authors attempted to develop real-time ultrasound-guided endoscopic surgery using a bur-hole-type probe. From November 2012 to March 2014, patients with hypertensive putaminal hemorrhage who underwent endoscopic hematoma removal were enrolled in this study. Real-time ultrasound guidance was performed with a bur-hole-type probe that was advanced via a second bur hole, which was placed in the temporal region. Ultrasound was used to guide insertion of the endoscope sheath as well as to provide information regarding the location of the hematoma during surgical evacuation. Finally, the cavity was irrigated with artificial cerebrospinal fluid and was observed as a low-echoic space, which facilitated detection of residual hematoma. Ten patients with putaminal hemorrhage>30 cm3 were included in this study. Their mean age (±SD) was 60.9±8.6 years, and the mean preoperative hematoma volume was 65.2±37.1 cm3. The mean percentage of hematoma that was evacuated was 96%±3%. None of the patients exhibited rebleeding after surgery. This navigation method was effective in demonstrating both the real-time location of the endoscope and real-time viewing of the residual hematoma. Use of ultrasound guidance minimized the occurrence of brain injury due to hematoma evacuation.

Miniature injection-molded optics for fiber-optic, in vivo confocal microscopy

NASA Astrophysics Data System (ADS)

Chidley, Matthew D.; Liang, Chen; Descour, Michael R.; Sung, Kung-Bin; Richards-Kortum, Rebecca R.; Gillenwater, Ann

2002-12-01

In collaboration with the Department of Biomedical Engineering at the University of Texas at Austin and the UT MD Anderson Cancer Center, a laser scanning fiber confocal reflectance microscope (FCRM) system has been designed and tested for in vivo detection of cervical and oral pre-cancers. This system along with specially developed diagnosis algorithms and techniques can achieve an unprecedented specificity and sensitivity for the diagnosis of pre-cancers in epithelial tissue. The FCRM imaging system consists of an NdYAG laser (1064 nm), scanning mirrors/optics, precision pinhole, detector, and an endoscopic probe (the objective). The objective is connected to the rest of the imaging system via a fiber bundle. The fiber bundle allows the rest of the system to be remotely positioned in a convenient location. Only the objective comes into contact with the patient. It is our intent that inexpensive mass-produced disposable endoscopic probes would be produced for large clinical trials. This paper touches on the general design process of developing a miniature, high numerical aperture, injection-molded (IM) objective. These IM optical designs are evaluated and modified based on manufacturing and application constraints. Based on these driving criteria, one specific optical design was chosen and a detailed tolerance analysis was conducted. The tolerance analysis was custom built to create a realistic statistical analysis for integrated IM lens elements that can be stacked one on top of another using micro-spheres resting in tiny circular grooves. These configurations allow each lens element to be rotated and possibly help compensate for predicted manufacturing errors. This research was supported by a grant from the National Institutes of Health (RO1 CA82880). Special thanks go to Applied Image Group/Optics for the numerous fabrication meetings concerning the miniature IM objective.

Ultrahigh sensitivity endoscopic camera using a new CMOS image sensor: providing with clear images under low illumination in addition to fluorescent images.

PubMed

Aoki, Hisae; Yamashita, Hiromasa; Mori, Toshiyuki; Fukuyo, Tsuneo; Chiba, Toshio

2014-11-01

We developed a new ultrahigh-sensitive CMOS camera using a specific sensor that has a wide range of spectral sensitivity characteristics. The objective of this study is to present our updated endoscopic technology that has successfully integrated two innovative functions; ultrasensitive imaging as well as advanced fluorescent viewing. Two different experiments were conducted. One was carried out to evaluate the function of the ultrahigh-sensitive camera. The other was to test the availability of the newly developed sensor and its performance as a fluorescence endoscope. In both studies, the distance from the endoscopic tip to the target was varied and those endoscopic images in each setting were taken for further comparison. In the first experiment, the 3-CCD camera failed to display the clear images under low illumination, and the target was hardly seen. In contrast, the CMOS camera was able to display the targets regardless of the camera-target distance under low illumination. Under high illumination, imaging quality given by both cameras was quite alike. In the second experiment as a fluorescence endoscope, the CMOS camera was capable of clearly showing the fluorescent-activated organs. The ultrahigh sensitivity CMOS HD endoscopic camera is expected to provide us with clear images under low illumination in addition to the fluorescent images under high illumination in the field of laparoscopic surgery.

Terahertz endoscopic imaging for colorectal cancer detection: Current status and future perspectives

PubMed Central

Doradla, Pallavi; Joseph, Cecil; Giles, Robert H

2017-01-01

Terahertz (THz) imaging is progressing as a robust platform for myriad applications in the field of security, health, and material science. The THz regime, which comprises wavelengths spanning from microns to millimeters, is non-ionizing and has very low photon energy: Making it inherently safe for biological imaging. Colorectal cancer is one of the most common causes of death in the world, while the conventional screening and standard of care yet relies exclusively on the physician’s experience. Researchers have been working on the development of a flexible THz endoscope, as a potential tool to aid in colorectal cancer screening. This involves building a single-channel THz endoscope, and profiling the THz response from colorectal tissue, and demonstrating endogenous contrast levels between normal and diseased tissue when imaging in reflection modality. The current level of contrast provided by the prototype THz endoscopic system represents a significant step towards clinical endoscopic application of THz technology for in-vivo colorectal cancer screening. The aim of this paper is to provide a short review of the recent advances in THz endoscopic technology and cancer imaging. In particular, the potential of single-channel THz endoscopic imaging for colonic cancer screening will be highlighted. PMID:28874955

21 CFR 884.4100 - Endoscopic electrocautery and accessories.

Code of Federal Regulations, 2012 CFR

2012-04-01

... coagulate fallopian tube tissue with a probe heated by low-voltage energy. This generic type of device may include the following accessories: electrical generators, probes, and electrical cables. (b...

21 CFR 884.4100 - Endoscopic electrocautery and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... coagulate fallopian tube tissue with a probe heated by low-voltage energy. This generic type of device may include the following accessories: electrical generators, probes, and electrical cables. (b...

21 CFR 884.4100 - Endoscopic electrocautery and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... coagulate fallopian tube tissue with a probe heated by low-voltage energy. This generic type of device may include the following accessories: electrical generators, probes, and electrical cables. (b...

21 CFR 884.4100 - Endoscopic electrocautery and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... coagulate fallopian tube tissue with a probe heated by low-voltage energy. This generic type of device may include the following accessories: electrical generators, probes, and electrical cables. (b...

Real-time endoscopic image orientation correction system using an accelerometer and gyrosensor.

PubMed

Lee, Hyung-Chul; Jung, Chul-Woo; Kim, Hee Chan

2017-01-01

The discrepancy between spatial orientations of an endoscopic image and a physician's working environment can make it difficult to interpret endoscopic images. In this study, we developed and evaluated a device that corrects the endoscopic image orientation using an accelerometer and gyrosensor. The acceleration of gravity and angular velocity were retrieved from the accelerometer and gyrosensor attached to the handle of the endoscope. The rotational angle of the endoscope handle was calculated using a Kalman filter with transmission delay compensation. Technical evaluation of the orientation correction system was performed using a camera by comparing the optical rotational angle from the captured image with the rotational angle calculated from the sensor outputs. For the clinical utility test, fifteen anesthesiology residents performed a video endoscopic examination of an airway model with and without using the orientation correction system. The participants reported numbers written on papers placed at the left main, right main, and right upper bronchi of the airway model. The correctness and the total time it took participants to report the numbers were recorded. During the technical evaluation, errors in the calculated rotational angle were less than 5 degrees. In the clinical utility test, there was a significant time reduction when using the orientation correction system compared with not using the system (median, 52 vs. 76 seconds; P = .012). In this study, we developed a real-time endoscopic image orientation correction system, which significantly improved physician performance during a video endoscopic exam.

Dynamic optical projection of acquired luminescence for aiding oncologic surgery

NASA Astrophysics Data System (ADS)

Sarder, Pinaki; Gullicksrud, Kyle; Mondal, Suman; Sudlow, Gail P.; Achilefu, Samuel; Akers, Walter J.

2013-12-01

Optical imaging enables real-time visualization of intrinsic and exogenous contrast within biological tissues. Applications in human medicine have demonstrated the power of fluorescence imaging to enhance visualization in dermatology, endoscopic procedures, and open surgery. Although few optical contrast agents are available for human medicine at this time, fluorescence imaging is proving to be a powerful tool in guiding medical procedures. Recently, intraoperative detection of fluorescent molecular probes that target cell-surface receptors has been reported for improvement in oncologic surgery in humans. We have developed a novel system, optical projection of acquired luminescence (OPAL), to further enhance real-time guidance of open oncologic surgery. In this method, collected fluorescence intensity maps are projected onto the imaged surface rather than via wall-mounted display monitor. To demonstrate proof-of-principle for OPAL applications in oncologic surgery, lymphatic transport of indocyanine green was visualized in live mice for intraoperative identification of sentinel lymph nodes. Subsequently, peritoneal tumors in a murine model of breast cancer metastasis were identified using OPAL after systemic administration of a tumor-selective fluorescent molecular probe. These initial results clearly show that OPAL can enhance adoption and ease-of-use of fluorescence imaging in oncologic procedures relative to existing state-of-the-art intraoperative imaging systems.

21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... high frequency electrical current through tissue between two electrical contacts of a probe. This generic type of device may include the following accessories: an electrical generator, probes, and...

21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2012 CFR

2012-04-01

... high frequency electrical current through tissue between two electrical contacts of a probe. This generic type of device may include the following accessories: an electrical generator, probes, and...

21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... high frequency electrical current through tissue between two electrical contacts of a probe. This generic type of device may include the following accessories: an electrical generator, probes, and...

21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... high frequency electrical current through tissue between two electrical contacts of a probe. This generic type of device may include the following accessories: an electrical generator, probes, and...

Morphologic three-dimensional scanning of fallopian tubes to assist ovarian cancer diagnosis

NASA Astrophysics Data System (ADS)

Madore, Wendy-Julie; De Montigny, Etienne; Deschênes, Andréanne; Benboujja, Fouzi; Leduc, Mikaël; Mes-Masson, Anne-Marie; Provencher, Diane M.; Rahimi, Kurosh; Boudoux, Caroline; Godbout, Nicolas

2017-07-01

The majority of high-grade serous ovarian cancers is now believed to originate in the fallopian tubes. Therefore, current practices include the pathological examination of excised fallopian tubes. Detection of tumors in the fallopian tubes using current clinical approaches remains difficult but is of critical importance to achieve accurate staging and diagnosis. Here, we present an intraoperative imaging system for the detection of human fallopian tube lesions. The system is based on optical coherence tomography (OCT) to access subepithelial tissue architecture. To demonstrate that OCT could identify lesions, we analyzed 180 OCT volumes taken from five different ovarian lesions and from healthy fallopian tubes, and compared them to standard pathological review. We demonstrated that qualitative features could be matched to pathological conditions. We then determined the feasibility of intraluminal imaging of intact human fallopian tubes by building a dedicated endoscopic single-fiber OCT probe to access the mucosal layer inside freshly excised specimens from five patients undergoing prophylactic surgeries. The probe insertion into the lumen acquired images over the entire length of the tubes without damaging the mucosa, providing the first OCT images of intact human fallopian tubes.

3-D endoscopic imaging using plenoptic camera.

PubMed

Le, Hanh N D; Decker, Ryan; Opferman, Justin; Kim, Peter; Krieger, Axel; Kang, Jin U

2016-06-01

Three-dimensional endoscopic imaging using plenoptic technique combined with F-matching algorithm has been pursued in this study. A custom relay optics was designed to integrate a commercial surgical straight endoscope with a plenoptic camera.

Laser scanning endoscope for diagnostic medicine

NASA Astrophysics Data System (ADS)

Ouimette, Donald R.; Nudelman, Sol; Spackman, Thomas; Zaccheo, Scott

1990-07-01

A new type of endoscope is being developed which utilizes an optical raster scanning system for imaging through an endoscope. The optical raster scanner utilizes a high speed, multifaceted, rotating polygon mirror system for horizontal deflection, and a slower speed galvanometer driven mirror as the vertical deflection system. When used in combination, the optical raster scanner traces out a raster similar to an electron beam raster used in television systems. This flying spot of light can then be detected by various types of photosensitive detectors to generate a video image of the surface or scene being illuminated by the scanning beam. The optical raster scanner has been coupled to an endoscope. The raster is projected down the endoscope, thereby illuminating the object to be imaged at the distal end of the endoscope. Elemental photodetectors are placed at the distal or proximal end of the endoscope to detect the reflected illumination from the flying spot of light. This time sequenced signal is captured by an image processor for display and processing. This technique offers the possibility for very small diameter endoscopes since illumination channel requirements are eliminated. Using various lasers, very specific spectral selectivity can be achieved to optimum contrast of specific lesions of interest. Using several laser lines, or a white light source, with detectors of specific spectral response, multiple spectrally selected images can be acquired simultaneously. The potential for co-linear therapy delivery while imaging is also possible.

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

PubMed

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.

High-speed upper-airway imaging using full-range optical coherence tomography

NASA Astrophysics Data System (ADS)

Jing, Joseph; Zhang, Jun; Loy, Anthony Chin; Wong, Brian J. F.; Chen, Zhongping

2012-11-01

Obstruction in the upper airway can often cause reductions in breathing or gas exchange efficiency and lead to rest disorders such as sleep apnea. Imaging diagnosis of the obstruction region has been accomplished using computed tomography (CT) and magnetic resonance imaging (MRI). However CT requires the use of ionizing radiation, and MRI typically requires sedation of the patient to prevent motion artifacts. Long-range optical coherence tomography (OCT) has the potential to provide high-speed three-dimensional tomographic images with high resolution and without the use of ionizing radiation. In this paper, we present work on the development of a long-range OCT endoscopic probe with 1.2 mm OD and 20 mm working distance used in conjunction with a modified Fourier domain swept source OCT system to acquire structural and anatomical datasets of the human airway. Imaging from the bottom of the larynx to the end of the nasal cavity is completed within 40 s.

Multiphoton gradient index endoscopy for evaluation of diseased human prostatic tissue ex vivo

NASA Astrophysics Data System (ADS)

Huland, David M.; Jain, Manu; Ouzounov, Dimitre G.; Robinson, Brian D.; Harya, Diana S.; Shevchuk, Maria M.; Singhal, Paras; Xu, Chris; Tewari, Ashutosh K.

2014-11-01

Multiphoton microscopy can instantly visualize cellular details in unstained tissues. Multiphoton probes with clinical potential have been developed. This study evaluates the suitability of multiphoton gradient index (GRIN) endoscopy as a diagnostic tool for prostatic tissue. A portable and compact multiphoton endoscope based on a 1-mm diameter, 8-cm length GRIN lens system probe was used. Fresh ex vivo samples were obtained from 14 radical prostatectomy patients and benign and malignant areas were imaged and correlated with subsequent H&E sections. Multiphoton GRIN endoscopy images of unfixed and unprocessed prostate tissue at a subcellular resolution are presented. We note several differences and identifying features of benign versus low-grade versus high-grade tumors and are able to identify periprostatic tissues such as adipocytes, periprostatic nerves, and blood vessels. Multiphoton GRIN endoscopy can be used to identify both benign and malignant lesions in ex vivo human prostate tissue and may be a valuable diagnostic tool for real-time visualization of suspicious areas of the prostate.

3-D endoscopic imaging using plenoptic camera

PubMed Central

Le, Hanh N. D.; Decker, Ryan; Opferman, Justin; Kim, Peter; Krieger, Axel

2017-01-01

Three-dimensional endoscopic imaging using plenoptic technique combined with F-matching algorithm has been pursued in this study. A custom relay optics was designed to integrate a commercial surgical straight endoscope with a plenoptic camera. PMID:29276806

Sparse aperture endoscope

DOEpatents

Fitch, J.P.

1999-07-06

An endoscope is disclosed which reduces the volume needed by the imaging part, maintains resolution of a wide diameter optical system, while increasing tool access, and allows stereographic or interferometric processing for depth and perspective information/visualization. Because the endoscope decreases the volume consumed by imaging optics such allows a larger fraction of the volume to be used for non-imaging tools, which allows smaller incisions in surgical and diagnostic medical applications thus produces less trauma to the patient or allows access to smaller volumes than is possible with larger instruments. The endoscope utilizes fiber optic light pipes in an outer layer for illumination, a multi-pupil imaging system in an inner annulus, and an access channel for other tools in the center. The endoscope is amenable to implementation as a flexible scope, and thus increases it's utility. Because the endoscope uses a multi-aperture pupil, it can also be utilized as an optical array, allowing stereographic and interferometric processing. 7 figs.

Sparse aperture endoscope

DOEpatents

Fitch, Joseph P.

1999-07-06

An endoscope which reduces the volume needed by the imaging part thereof, maintains resolution of a wide diameter optical system, while increasing tool access, and allows stereographic or interferometric processing for depth and perspective information/visualization. Because the endoscope decreases the volume consumed by imaging optics such allows a larger fraction of the volume to be used for non-imaging tools, which allows smaller incisions in surgical and diagnostic medical applications thus produces less trauma to the patient or allows access to smaller volumes than is possible with larger instruments. The endoscope utilizes fiber optic light pipes in an outer layer for illumination, a multi-pupil imaging system in an inner annulus, and an access channel for other tools in the center. The endoscope is amenable to implementation as a flexible scope, and thus increases the utility thereof. Because the endoscope uses a multi-aperture pupil, it can also be utilized as an optical array, allowing stereographic and interferometric processing.

A 3D photographic capsule endoscope system with full field of view

NASA Astrophysics Data System (ADS)

Ou-Yang, Mang; Jeng, Wei-De; Lai, Chien-Cheng; Kung, Yi-Chinn; Tao, Kuan-Heng

2013-09-01

Current capsule endoscope uses one camera to capture the surface image in the intestine. It can only observe the abnormal point, but cannot know the exact information of this abnormal point. Using two cameras can generate 3D images, but the visual plane changes while capsule endoscope rotates. It causes that two cameras can't capture the images information completely. To solve this question, this research provides a new kind of capsule endoscope to capture 3D images, which is 'A 3D photographic capsule endoscope system'. The system uses three cameras to capture images in real time. The advantage is increasing the viewing range up to 2.99 times respect to the two camera system. The system can accompany 3D monitor provides the exact information of symptom points, helping doctors diagnose the disease.

An All-Fiber-Optic Combined System of Noncontact Photoacoustic Tomography and Optical Coherence Tomography

PubMed Central

Eom, Jonghyun; Shin, Jun Geun; Park, Soongho; Rim, Sunghwan; Lee, Byeong Ha

2016-01-01

We propose an all-fiber-based dual-modal imaging system that combines noncontact photoacoustic tomography (PAT) and optical coherence tomography (OCT). The PAT remotely measures photoacoustic (PA) signals with a 1550-nm laser on the surface of a sample by utilizing a fiber interferometer as an ultrasound detector. The fiber-based OCT, employing a swept-source laser centered at 1310 nm, shares the sample arm of the PAT system. The fiber-optic probe for the combined system was homemade with a lensed single-mode fiber (SMF) and a large-core multimode fiber (MMF). The compact and robust common probe is capable of obtaining both the PA and the OCT signals at the same position without any physical contact. Additionally, the MMF of the probe delivers the short pulses of a Nd:YAG laser to efficiently excite the PA signals. We experimentally demonstrate the feasibility of the proposed dual-modal system with a phantom made of a fishing line and a black polyethylene terephthalate fiber in a tissue mimicking solution. The all-fiber-optic system, capable of providing complementary information about absorption and scattering, has a promising potential in minimally invasive and endoscopic imaging. PMID:27213392

An All-Fiber-Optic Combined System of Noncontact Photoacoustic Tomography and Optical Coherence Tomography.

PubMed

Eom, Jonghyun; Shin, Jun Geun; Park, Soongho; Rim, Sunghwan; Lee, Byeong Ha

2016-05-20

We propose an all-fiber-based dual-modal imaging system that combines noncontact photoacoustic tomography (PAT) and optical coherence tomography (OCT). The PAT remotely measures photoacoustic (PA) signals with a 1550-nm laser on the surface of a sample by utilizing a fiber interferometer as an ultrasound detector. The fiber-based OCT, employing a swept-source laser centered at 1310 nm, shares the sample arm of the PAT system. The fiber-optic probe for the combined system was homemade with a lensed single-mode fiber (SMF) and a large-core multimode fiber (MMF). The compact and robust common probe is capable of obtaining both the PA and the OCT signals at the same position without any physical contact. Additionally, the MMF of the probe delivers the short pulses of a Nd:YAG laser to efficiently excite the PA signals. We experimentally demonstrate the feasibility of the proposed dual-modal system with a phantom made of a fishing line and a black polyethylene terephthalate fiber in a tissue mimicking solution. The all-fiber-optic system, capable of providing complementary information about absorption and scattering, has a promising potential in minimally invasive and endoscopic imaging.

Endoscopic Optical Coherence Tomography for Clinical Gastroenterology

PubMed Central

Tsai, Tsung-Han; Fujimoto, James G.; Mashimo, Hiroshi

2014-01-01

Optical coherence tomography (OCT) is a real-time optical imaging technique that is similar in principle to ultrasonography, but employs light instead of sound waves and allows depth-resolved images with near-microscopic resolution. Endoscopic OCT allows the evaluation of broad-field and subsurface areas and can be used ancillary to standard endoscopy, narrow band imaging, chromoendoscopy, magnification endoscopy, and confocal endomicroscopy. This review article will provide an overview of the clinical utility of endoscopic OCT in the gastrointestinal tract and of recent achievements using state-of-the-art endoscopic 3D-OCT imaging systems. PMID:26852678

Towards standardized assessment of endoscope optical performance: geometric distortion

NASA Astrophysics Data System (ADS)

Wang, Quanzeng; Desai, Viraj N.; Ngo, Ying Z.; Cheng, Wei-Chung; Pfefer, Joshua

2013-12-01

Technological advances in endoscopes, such as capsule, ultrathin and disposable devices, promise significant improvements in safety, clinical effectiveness and patient acceptance. Unfortunately, the industry lacks test methods for preclinical evaluation of key optical performance characteristics (OPCs) of endoscopic devices that are quantitative, objective and well-validated. As a result, it is difficult for researchers and developers to compare image quality and evaluate equivalence to, or improvement upon, prior technologies. While endoscope OPCs include resolution, field of view, and depth of field, among others, our focus in this paper is geometric image distortion. We reviewed specific test methods for distortion and then developed an objective, quantitative test method based on well-defined experimental and data processing steps to evaluate radial distortion in the full field of view of an endoscopic imaging system. Our measurements and analyses showed that a second-degree polynomial equation could well describe the radial distortion curve of a traditional endoscope. The distortion evaluation method was effective for correcting the image and can be used to explain other widely accepted evaluation methods such as picture height distortion. Development of consensus standards based on promising test methods for image quality assessment, such as the method studied here, will facilitate clinical implementation of innovative endoscopic devices.

Endoscopic techniques in aesthetic plastic surgery.

PubMed

McCain, L A; Jones, G

1995-01-01

There has been an explosive interest in endoscopic techniques by plastic surgeons over the past two years. Procedures such as facial rejuvenation, breast augmentation and abdominoplasty are being performed with endoscopic assistance. Endoscopic operations require a complex setup with components such as video camera, light sources, cables and hard instruments. The Hopkins Rod Lens system consists of optical fibers for illumination, an objective lens, an image retrieval system, a series of rods and lenses, and an eyepiece for image collection. Good illumination of the body cavity is essential for endoscopic procedures. Placement of the video camera on the eyepiece of the endoscope gives a clear, brightly illuminated large image on the monitor. The video monitor provides the surgical team with the endoscopic image. It is important to become familiar with the equipment before actually doing cases. Several options exist for staff education. In the operating room the endoscopic cart needs to be positioned to allow a clear unrestricted view of the video monitor by the surgeon and the operating team. Fogging of the endoscope may be prevented during induction by using FREDD (a fog reduction/elimination device) or a warm bath. The camera needs to be white balanced. During the procedure, the nurse monitors the level of dissection and assesses for clogging of the suction.

Volume holographic reflection endoscope for in-vivo ovarian cancer clinical studies

NASA Astrophysics Data System (ADS)

Howlett, I. D.; Gordon, M.; Brownlee, J. W.; Barton, J. K.; Kostuk, R. K.

2014-03-01

We present the design for an endoscopic system capable of imaging tissues of the ovary at two selected imaging depths simultaneously. The method utilizes a multiplexed volume hologram to select wavefronts from different depths within the tissue. It is the first demonstration of an endoscopic volume holographic imaging system. The endoscope uses both gradient index (GRIN) optical components and off the shelf singlet lenses to relay an image from the distal tip to the proximal end. The endoscope has a minimum diameter of 3.75 mm. The system length is 30 cm which is connected to a handle that includes the holographic components and optics that relay the image to a camera. Preliminary evaluation of the endoscope was performed with tissue phantoms and calibrated targets, which shows lateral resolution ≍ 4 μm at an operating wavelength of 660 nm. The hologram is recorded in phenanthraquinone doped poly methacrylate and is designed to produce images from two tissue depths. One image is obtained at the tissue surface and the second 70 μm below the surface. This method requires no mechanical scanning and acquires an image at the camera frame rate. The preliminary ex-vivo results show good correlation with histology sections of the same tissue sections.

A beam-splitter-type 3-D endoscope for front view and front-diagonal view images.

PubMed

Kamiuchi, Hiroki; Masamune, Ken; Kuwana, Kenta; Dohi, Takeyoshi; Kim, Keri; Yamashita, Hiromasa; Chiba, Toshio

2013-01-01

In endoscopic surgery, surgeons must manipulate an endoscope inside the body cavity to observe a large field-of-view while estimating the distance between surgical instruments and the affected area by reference to the size or motion of the surgical instruments in 2-D endoscopic images on a monitor. Therefore, there is a risk of the endoscope or surgical instruments physically damaging body tissues. To overcome this problem, we developed a Ø7- mm 3-D endoscope that can switch between providing front and front-diagonal view 3-D images by simply rotating its sleeves. This 3-D endoscope consists of a conventional 3-D endoscope and an outer and inner sleeve with a beam splitter and polarization plates. The beam splitter was used for visualizing both the front and front-diagonal view and was set at 25° to the outer sleeve's distal end in order to eliminate a blind spot common to both views. Polarization plates were used to avoid overlap of the two views. We measured signal-to-noise ratio (SNR), sharpness, chromatic aberration (CA), and viewing angle of this 3-D endoscope and evaluated its feasibility in vivo. Compared to the conventional 3-D endoscope, SNR and sharpness of this 3-D endoscope decreased by 20 and 7 %, respectively. No significant difference was found in CA. The viewing angle for both the front and front-diagonal views was about 50°. In the in vivo experiment, this 3-D endoscope can provide clear 3-D images of both views by simply rotating its inner sleeve. The developed 3-D endoscope can provide the front and front-diagonal view by simply rotating the inner sleeve, therefore the risk of damage to fragile body tissues can be significantly decreased.

Confocal Endomicroscopy: Instrumentation and Medical Applications

PubMed Central

Jabbour, Joey M.; Saldua, Meagan A.; Bixler, Joel N.; Maitland, Kristen C.

2013-01-01

Advances in fiber optic technology and miniaturized optics and mechanics have propelled confocal endomicroscopy into the clinical realm. This high resolution, non-invasive imaging technology provides the ability to microscopically evaluate cellular and sub-cellular features in tissue in vivo by optical sectioning. Because many cancers originate in epithelial tissues accessible by endoscopes, confocal endomicroscopy has been explored to detect regions of possible neoplasia at an earlier stage by imaging morphological features in vivo that are significant in histopathologic evaluation. This technique allows real-time assessment of tissue which may improve diagnostic yield by guiding biopsy. Research and development continues to reduce the overall size of the imaging probe, increase the image acquisition speed, and improve resolution and field of view of confocal endomicroscopes. Technical advances will continue to enable application to less accessible organs and more complex systems in the body. Lateral and axial resolutions down to 0.5 μm and 3 μm, respectively, field of view as large as 800×450 μm, and objective lens and total probe outer diameters down to 350 μm and 1.25 mm, respectively, have been achieved. We provide a review of the historical developments of confocal imaging in vivo, the evolution of endomicroscope instrumentation, and the medical applications of confocal endomicroscopy. PMID:21994069

Multi-modality endoscopic imaging for the detection of colorectal cancer

NASA Astrophysics Data System (ADS)

Wall, Richard Andrew

Optical coherence tomography (OCT) is an imaging method that is considered the optical analog to ultrasound, using the technique of optical interferometry to construct two-dimensional depth-resolved images of tissue microstructure. With a resolution on the order of 10 um and a penetration depth of 1-2 mm in highly scattering tissue, fiber optics-coupled OCT is an ideal modality for the inspection of the mouse colon with its miniaturization capabilities. In the present study, the complementary modalities laser-induced fluorescence (LIF), which offers information on the biochemical makeup of the tissue, and surface magnifying chromoendoscopy, which offers high contrast surface visualization, are combined with OCT in endoscopic imaging systems for the greater specificity and sensitivity in the differentiation between normal and neoplastic tissue, and for the visualization of biomarkers which are indicative of early events in colorectal carcinogenesis. Oblique incidence reflectometry (OIR) also offers advantages, allowing the calculation of bulk tissue optical properties for use as a diagnostic tool. The study was broken up into three specific sections. First, a dual-modality OCTLIF imaging system was designed, capable of focusing light over 325-1300 nm using a reflective distal optics design. A dual-modality fluorescence-based SMC-OCT system was then designed and constructed, capable of resolving the stained mucosal crypt structure of the in vivo mouse colon. The SMC-OCT instrument's OIR capabilities were then modeled, as a modified version of the probe was used measure tissue scattering and absorption coefficients.

21 CFR 884.4160 - Unipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... temperatures by directing a high frequency electrical current through the tissue between an energized probe and... generator, probes and electrical cables, and a patient grounding plate. This generic type of device does not...

21 CFR 884.4160 - Unipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... temperatures by directing a high frequency electrical current through the tissue between an energized probe and... generator, probes and electrical cables, and a patient grounding plate. This generic type of device does not...

21 CFR 884.4160 - Unipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2012 CFR

2012-04-01

... temperatures by directing a high frequency electrical current through the tissue between an energized probe and... generator, probes and electrical cables, and a patient grounding plate. This generic type of device does not...

21 CFR 884.4160 - Unipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... temperatures by directing a high frequency electrical current through the tissue between an energized probe and... generator, probes and electrical cables, and a patient grounding plate. This generic type of device does not...

21 CFR 884.4160 - Unipolar endoscopic coagulator-cutter and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... temperatures by directing a high frequency electrical current through the tissue between an energized probe and... generator, probes and electrical cables, and a patient grounding plate. This generic type of device does not...

Photoacoustic endoscopy probe using a coherent fibre-optic bundle and Fabry-Pérot ultrasound sensor (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ansari, Rehman; Beard, Paul C.; Zhang, Edward Z.; Desjardins, Adrien E.

2016-03-01

There is considerable interest in the development of photoacoustic endoscopy (PAE) probes for the clinical assessment of pathologies in the gastrointestinal (GI) tract, guiding minimally invasive laparoscopic surgeries and applications in foetal medicine. However, most previous PAE probes integrate mechanical scanners and piezoelectric transducers at the distal end which can be technically complex, expensive and pose challenges in achieving the necessary level of miniaturisation. We present two novel all-optical forward-viewing endoscopic probes operating in widefield tomography mode that have the potential to overcome these limitations. In one configuration, the probe comprises a transparent 40 MHz Fabry-Pérot ultrasound sensor deposited at the tip of a rigid, 3 mm diameter coherent fibre-optic bundle. In this way, the distal end of coherent fibre bundle acts as a 2D array of wideband ultrasound detectors. In another configuration, an optical relay is used between the distal end face of flexible fibre bundle and the Fabry-Pérot sensor to enlarge the lateral field of view to 6 mm x 6 mm. In both configurations, the pulsed excitation laser beam is full-field coupled into the fibre bundle at the proximal end for uniform backward-mode illumination of the tissue at the probe tip. In order to record the photoacoustic waves arriving at the probe tip, the proximal end of the fibre bundle is optically scanned in 2D with a CW wavelength-tunable interrogation laser beam thereby interrogating different spatial points on the sensor. A time-reversal image reconstruction algorithm was used to reconstruct a 3D image from the detected signals. The 3D field of view of the flexible PAE probe is 6 mm x 6 mm x 6 mm and the axial and lateral spatial resolution is 30 µm and 90 µm, respectively. 3D imaging capability is demonstrated using tissue phantoms, ex vivo tissues and in vivo. To the best of our knowledge, this is the first forward-viewing implementation of a photoacoustic endoscopy probe, and it offers several advantages over previous distal-end scanning probes. These include a high degree of miniaturisation, no moving parts at the distal end and simple and inexpensive fabrication with the potential to realise disposable probes for clinical imaging of the GI tract and other minimally invasive applications.

Can an endocytoscope system (ECS) predict histology in neoplastic lesions?

PubMed

Eberl, T; Jechart, G; Probst, A; Golczyk, M; Bittinger, M; Scheubel, R; Arnholdt, H; Knuechel, R; Messmann, H

2007-06-01

An endocytoscope system (ECS) has recently been developed with the possibility of super-high magnification of gastrointestinal mucosa, thus allowing in vivo imaging of living cells. The aim of the present study was to assess the potential of ECS in the prediction of histology in both normal gastrointestinal mucosa and neoplastic lesions. In total, 76 patients (57 men, 19 women; age range 37-86 years) with neoplastic lesions in the esophagus, stomach, or colon were enrolled into the study and underwent esophagogastroduodenoscopy or colonoscopy. After staining with 1% methylene blue, the mucosa was examined with the ECS probe (x 450 and x 1100 magnification), and video sequences were recorded on video disk. Biopsies from the examined areas were taken for histology and served as the gold standard. The endocytoscope video sequences were evaluated by two blinded pathologists. Finally the results were compared with those resulting from the evaluation of an experienced endoscopist who was aware of the macroscopic endoscopic pictures and the endocytoscope image results. A total of 25 patients with esophageal lesions, 28 patients with colonic lesions, and 23 patients with gastric lesions were examined. The sensitivity and specificity for the evaluation of the blinded pathologists was 81% and 100%, respectively, in the esophagus, 56% and 89% in the stomach, and 79% and 90% in the colon. If an endoscopist evaluated the endocytoscopic pictures in combination with the macroscopic endoscopic images sensitivity and specificity increased significantly. First experiences with ECS show good sensitivity rates even by blinded assessment for esophageal and colonic lesions. Sensitivity for neoplastic lesions in the stomach is lower because of gastric mucous secretion. Combining the endoscopic and cytoscopic appearance of the lesion may further enhance the diagnostic value of the method.

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

PubMed

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.

Ultrahigh-resolution endoscopic optical coherence tomography

NASA Astrophysics Data System (ADS)

Chen, Yu; Herz, Paul R.; Hsiung, Pei-Lin; Aguirre, Aaron D.; Mashimo, Hiroshi; Desai, Saleem; Pedrosa, Macos; Koski, Amanda; Schmitt, Joseph M.; Fujimoto, James G.

2005-01-01

Early detection of gastrointestinal cancer is essential for the patient treatment and medical care. Endoscopically guided biopsy is currently the gold standard for the diagnosis of early esophageal cancer, but can suffer from high false negative rates due to sampling errors. Optical coherence tomography (OCT) is an emerging medical imaging technology which can generate high resolution, cross-sectional images of tissue in situ and in real time, without the removal of tissue specimen. Although endoscopic OCT has been used successfully to identify certain pathologies in the gastrointestinal tract, the resolution of current endoscopic OCT systems has been limited to 10 - 15 m for clinical procedures. In this study, in vivo imaging of the gastrointestinal tract is demonstrated at a three-fold higher resolution (< 5 m), using a portable, broadband, Cr4+:Forsterite laser as the optical light source. Images acquired from the esophagus, gastro-esophageal junction and colon on animal model display tissue microstructures and architectural details at high resolution, and the features observed in the OCT images are well-matched with histology. The clinical feasibility study is conducted through delivering OCT imaging catheter using standard endoscope. OCT images of normal esophagus, Barrett's esophagus, and esophageal cancers are demonstrated with distinct features. The ability of high resolution endoscopic OCT to image tissue morphology at an unprecedented resolution in vivo would facilitate the development of OCT as a potential imaging modality for early detection of neoplastic changes.

Chip-on-the-tip ultra-compact flexible endoscopic epifluorescence video-microscope for in-vivo imaging in medical and biomedical fields

NASA Astrophysics Data System (ADS)

Matz, Gregor; Messerschmidt, Bernhard; Göbel, Werner; Filser, Severin; Betz, Christian; Kunze, Marcel; Flaemig, Sven; Ehrhardt, André; Irion, Klaus-Martin; Herms, Jochen; Gross, Herbert

2017-02-01

We demonstrate a flexible stand-alone, minimally invasive video-endomicroscope with an outer diameter of 1.6 mm and a length of the rigid tip of 6.7 mm that enables surgeons and biologists to image hardly accessible regions in-vivo in epifluorescence mode. The 60 mg light device improves state-of-the-art objectives by a double deflection approach using a side-fire fiber in combination with spherical microlenses, GRIN-lenses with a specific adapted gradient index profile and an extremely miniaturized chip-on-the-tip camera to achieve an excellent imaging quality. A high NA of 0.7 enables the observation of subcellular features within the entire field of view with a diameter of 183 μm, assure a bright and high-contrast image and promise a good overview during the intervention. Ex-vivo measurements of biological samples confirmed the functionality of the probe.

Fabrication and analysis of cylindrical diffusing optical fiber probe for photodynamic therapy in cancer treatment

NASA Astrophysics Data System (ADS)

Park, Gaye; Lee, HyeYeon; Cho, HyungSu; Kim, DaeYoung; Han, JaeWan; Ouh, ChiHwan; Jung, ChangHyun

2018-02-01

The treatment using photodynamic therapy (PDT) among cancer treatment methods shows remedial value in various cancers. The optical fiber probe infiltrates into affected parts of the tissues that are difficult to access, such as pancreatic cancer, carcinoma of extrahepatic bile duct, prostate cancer, and bladder cancer by using endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography (EUS) with various types of diffusing tips. In this study, we developed cylindrical diffusing optical fiber probe (CDOFP) for PDT, manufactured ball-shaped end which is easily infiltrated into tissues with diffusing length ranging from 10mm to 40mm through precision laser processing, and conducted beam profile characterization of manufactured CDOFP. Also, chemical reaction between photo-sensitizer and laser in PDT is important, and hence the thermal effect in tissues as per diffusing length of probe was also studied as it was used in a recent study.

Sterilization, high-level disinfection, and environmental cleaning.

PubMed

Rutala, William A; Weber, David J

2011-03-01

Failure to perform proper disinfection and sterilization of medical devices may lead to introduction of pathogens, resulting in infection. New techniques have been developed for achieving high-level disinfection and adequate environmental cleanliness. This article examines new technologies for sterilization and high-level disinfection of critical and semicritical items, respectively, and because semicritical items carry the greatest risk of infection, the authors discuss reprocessing semicritical items such as endoscopes and automated endoscope reprocessors, endocavitary probes, prostate biopsy probes, tonometers, laryngoscopes, and infrared coagulation devices. In addition, current issues and practices associated with environmental cleaning are reviewed. Copyright © 2011. Published by Elsevier Inc.

A feasibility study of an integrated NIR/gamma/visible imaging system for endoscopic sentinel lymph node mapping.

PubMed

Kang, Han Gyu; Lee, Ho-Young; Kim, Kyeong Min; Song, Seong-Hyun; Hong, Gun Chul; Hong, Seong Jong

2017-01-01

The aim of this study is to integrate NIR, gamma, and visible imaging tools into a single endoscopic system to overcome the limitation of NIR using gamma imaging and to demonstrate the feasibility of endoscopic NIR/gamma/visible fusion imaging for sentinel lymph node (SLN) mapping with a small animal. The endoscopic NIR/gamma/visible imaging system consists of a tungsten pinhole collimator, a plastic focusing lens, a BGO crystal (11 × 11 × 2 mm 3 ), a fiber-optic taper (front = 11 × 11 mm 2 , end = 4 × 4 mm 2 ), a 122-cm long endoscopic fiber bundle, an NIR emission filter, a relay lens, and a CCD camera. A custom-made Derenzo-like phantom filled with a mixture of 99m Tc and indocyanine green (ICG) was used to assess the spatial resolution of the NIR and gamma images. The ICG fluorophore was excited using a light-emitting diode (LED) with an excitation filter (723-758 nm), and the emitted fluorescence photons were detected with an emission filter (780-820 nm) for a duration of 100 ms. Subsequently, the 99m Tc distribution in the phantom was imaged for 3 min. The feasibility of in vivo SLN mapping with a mouse was investigated by injecting a mixture of 99m Tc-antimony sulfur colloid (12 MBq) and ICG (0.1 mL) into the right paw of the mouse (C57/B6) subcutaneously. After one hour, NIR, gamma, and visible images were acquired sequentially. Subsequently, the dissected SLN was imaged in the same way as the in vivo SLN mapping. The NIR, gamma, and visible images of the Derenzo-like phantom can be obtained with the proposed endoscopic imaging system. The NIR/gamma/visible fusion image of the SLN showed a good correlation among the NIR, gamma, and visible images both for the in vivo and ex vivo imaging. We demonstrated the feasibility of the integrated NIR/gamma/visible imaging system using a single endoscopic fiber bundle. In future, we plan to investigate miniaturization of the endoscope head and simultaneous NIR/gamma/visible imaging with dichroic mirrors and three CCD cameras. © 2016 American Association of Physicists in Medicine.

A high definition Mueller polarimetric endoscope for tissue characterisation (Conference Presentation)

NASA Astrophysics Data System (ADS)

Qi, Ji; Elson, Daniel

2016-03-01

The mechanism of most medical endoscopes is based on the interaction between light and biological tissue, inclusive of absorption, elastic scattering and fluorescence. In essence, the metrics of those interactions are obtained from the fundamental properties of light as an electro-magnetic waves, namely, the radiation intensity and wavelength. As another fundamental property of light, polarisation can not only reveal tissue scattering and absorption information from a different perspective, but is also able to provide a fresh insight into directional tissue birefringence properties induced by birefringent compositions and anisotropic fibrous structures, such as collagen, elastin, muscle fibre, etc at the same time. Here we demonstrate a low cost high definition Muller polarimetric endoscope with minimal alteration of a rigid endoscope. By imaging birefringent tissue mimicking phantoms and a porcine bladder, we show that this novel endoscopic imaging modality is able to provide different information of interest from unpolarised endoscopic imaging, including linear depolarization, circular depolarization, birefringence, optic axis orientation and dichroism. This endoscope can potentially be employed for better tissue visualisation and benefit endoscopic investigations and intra-operative guidance.

Quantitative imaging of the human upper airway: instrument design and clinical studies

NASA Astrophysics Data System (ADS)

Leigh, M. S.; Armstrong, J. J.; Paduch, A.; Sampson, D. D.; Walsh, J. H.; Hillman, D. R.; Eastwood, P. R.

2006-08-01

Imaging of the human upper airway is widely used in medicine, in both clinical practice and research. Common imaging modalities include video endoscopy, X-ray CT, and MRI. However, no current modality is both quantitative and safe to use for extended periods of time. Such a capability would be particularly valuable for sleep research, which is inherently reliant on long observation sessions. We have developed an instrument capable of quantitative imaging of the human upper airway, based on endoscopic optical coherence tomography. There are no dose limits for optical techniques, and the minimally invasive imaging probe is safe for use in overnight studies. We report on the design of the instrument and its use in preliminary clinical studies, and we present results from a range of initial experiments. The experiments show that the instrument is capable of imaging during sleep, and that it can record dynamic changes in airway size and shape. This information is useful for research into sleep disorders, and potentially for clinical diagnosis and therapies.

Panorama imaging for image-to-physical registration of narrow drill holes inside spongy bones

NASA Astrophysics Data System (ADS)

Bergmeier, Jan; Fast, Jacob Friedemann; Ortmaier, Tobias; Kahrs, Lüder Alexander

2017-03-01

Image-to-physical registration based on volumetric data like computed tomography on the one side and intraoperative endoscopic images on the other side is an important method for various surgical applications. In this contribution, we present methods to generate panoramic views from endoscopic recordings for image-to-physical registration of narrow drill holes inside spongy bone. One core application is the registration of drill poses inside the mastoid during minimally invasive cochlear implantations. Besides the development of image processing software for registration, investigations are performed on a miniaturized optical system, achieving 360° radial imaging with one shot by extending a conventional, small, rigid, rod lens endoscope. A reflective cone geometry is used to deflect radially incoming light rays into the endoscope optics. Therefore, a cone mirror is mounted in front of a conventional 0° endoscope. Furthermore, panoramic images of inner drill hole surfaces in artificial bone material are created. Prior to drilling, cone beam computed tomography data is acquired from this artificial bone and simulated endoscopic views are generated from this data. A qualitative and quantitative image comparison of resulting views in terms of image-to-image registration is performed. First results show that downsizing of panoramic optics to a diameter of 3mm is possible. Conventional rigid rod lens endoscopes can be extended to produce suitable panoramic one-shot image data. Using unrolling and stitching methods, images of the inner drill hole surface similar to computed tomography image data of the same surface were created. Registration is performed on ten perturbations of the search space and results in target registration errors of (0:487 +/- 0:438)mm at the entry point and (0:957 +/- 0:948)mm at the exit as well as an angular error of (1:763 +/- 1:536)°. The results show suitability of this image data for image-to-image registration. Analysis of the error components in different directions reveals a strong influence of the pattern structure, meaning higher diversity results into smaller errors.

Advanced endoscopic imaging in gastric neoplasia and preneoplasia

PubMed Central

Lee, Jonathan W J; Lim, Lee Guan; Yeoh, Khay Guan

2017-01-01

Conventional white light endoscopy remains the current standard in routine clinical practice for early detection of gastric cancer. However, it may not accurately diagnose preneoplastic gastric lesions. The technological advancements in the field of endoscopic imaging for gastric lesions are fast growing. This article reviews currently available advanced endoscopic imaging modalities, in particular chromoendoscopy, narrow band imaging and confocal laser endomicroscopy, and their corresponding evidence shown to improve diagnosis of preneoplastic gastric lesions. Raman spectrometry and polarimetry are also introduced as promising emerging technologies. PMID:28176895

Comparison of methods for quantitative evaluation of endoscopic distortion

NASA Astrophysics Data System (ADS)

Wang, Quanzeng; Castro, Kurt; Desai, Viraj N.; Cheng, Wei-Chung; Pfefer, Joshua

2015-03-01

Endoscopy is a well-established paradigm in medical imaging, and emerging endoscopic technologies such as high resolution, capsule and disposable endoscopes promise significant improvements in effectiveness, as well as patient safety and acceptance of endoscopy. However, the field lacks practical standardized test methods to evaluate key optical performance characteristics (OPCs), in particular the geometric distortion caused by fisheye lens effects in clinical endoscopic systems. As a result, it has been difficult to evaluate an endoscope's image quality or assess its changes over time. The goal of this work was to identify optimal techniques for objective, quantitative characterization of distortion that are effective and not burdensome. Specifically, distortion measurements from a commercially available distortion evaluation/correction software package were compared with a custom algorithm based on a local magnification (ML) approach. Measurements were performed using a clinical gastroscope to image square grid targets. Recorded images were analyzed with the ML approach and the commercial software where the results were used to obtain corrected images. Corrected images based on the ML approach and the software were compared. The study showed that the ML method could assess distortion patterns more accurately than the commercial software. Overall, the development of standardized test methods for characterizing distortion and other OPCs will facilitate development, clinical translation, manufacturing quality and assurance of performance during clinical use of endoscopic technologies.

Development of terahertz endoscopic system for cancer detection

NASA Astrophysics Data System (ADS)

Doradla, Pallavi; Alavi, Karim; Joseph, Cecil S.; Giles, Robert H.

2016-02-01

Terahertz (THz) imaging is emerging as a robust platform for a myriad of applications in the fields of security, health, astronomy and material science. The terahertz regime with wavelengths spanning from microns to millimeters is a potentially safe and noninvasive medical imaging modality for detecting cancers. Endoscopic imaging systems provide high flexibility in examining the interior surfaces of an organ or tissue. Researchers have been working on the development of THz endoscopes with photoconductive antennas, which necessarily operate under high voltage, and require at least two channels to measure the reflected signal from the specimen. This manuscript provides the design and imperative steps involved in the development of a single-channel terahertz endoscopic system. The continuous-wave terahertz imaging system utilizes a single flexible terahertz waveguide channel to transmit and collect the back reflected intrinsic terahertz signal from the sample and is capable of operation in both transmission and reflection modalities. To determine the feasibility of using a terahertz endoscope for cancer detection, the co- and cross-polarized terahertz remittance from human colonic tissue specimens were collected at 584 GHz frequency. The two dimensional terahertz images obtained using polarization specific detection exhibited intrinsic contrast between cancerous and normal regions of fresh colorectal tissue. The level of contrast observed using endoscopic imaging correlates well with the contrast levels observed in the free space ex vivo terahertz reflectance studies of human colonic tissue. The prototype device developed in this study represents a significant step towards clinical endoscopic application of THz technology for in vivo colon cancer screening.

A dual-reflective electrothermal MEMS micromirror for full circumferential scanning endoscopic imaging

NASA Astrophysics Data System (ADS)

Wu, Lei; Xie, Huikai

2008-02-01

This paper reports the design, fabrication and measurements of a dual-reflective, single-crystal silicon based micromirror that can perform full circumferential scanning (FCS) for endoscopic optical coherence tomography (EOCT). In the proposed FCS-EOCT probe, two optical fibers are used to deliver light beams to either surface of the micromirror, which can rotate +/-45° (or 90°) and thus a 180° optical scanning is obtained from each mirror surface, resulting in full circumferential scans. A novel surface- and bulk-combined micromachining process based on SOI wafers is developed for fabricating the dual reflective micromirror. The single-crystal-silicon device layer of SOI wafers is used for mirror flatness, and Al is coated on both sides for high reflectivity. With one light beam delivered to each mirror surface, full 360° scans have been observed. Other measured data include the resonant frequency: 328Hz, radius of curvatures: - 124 mm (front surface) and 127 mm (back surface), and the reflectances: 81.3% (front surface) and 79.0% (back surface).

Advanced Endoscopic Navigation: Surgical Big Data, Methodology, and Applications.

PubMed

Luo, Xiongbiao; Mori, Kensaku; Peters, Terry M

2018-06-04

Interventional endoscopy (e.g., bronchoscopy, colonoscopy, laparoscopy, cystoscopy) is a widely performed procedure that involves either diagnosis of suspicious lesions or guidance for minimally invasive surgery in a variety of organs within the body cavity. Endoscopy may also be used to guide the introduction of certain items (e.g., stents) into the body. Endoscopic navigation systems seek to integrate big data with multimodal information (e.g., computed tomography, magnetic resonance images, endoscopic video sequences, ultrasound images, external trackers) relative to the patient's anatomy, control the movement of medical endoscopes and surgical tools, and guide the surgeon's actions during endoscopic interventions. Nevertheless, it remains challenging to realize the next generation of context-aware navigated endoscopy. This review presents a broad survey of various aspects of endoscopic navigation, particularly with respect to the development of endoscopic navigation techniques. First, we investigate big data with multimodal information involved in endoscopic navigation. Next, we focus on numerous methodologies used for endoscopic navigation. We then review different endoscopic procedures in clinical applications. Finally, we discuss novel techniques and promising directions for the development of endoscopic navigation.

Endoscopic third ventriculostomy

PubMed Central

Yadav, Yad Ram; Parihar, Vijay; Pande, Sonjjay; Namdev, Hemant; Agarwal, Moneet

2012-01-01

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 long term follow up. PMID:22865970

Performance evaluation of stereo endoscopic imaging system incorporating TFT-LCD.

PubMed

Song, C-G; Park, S-K

2005-01-01

This paper presents a 3D endoscopic video system designed to improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery. In a comparison of the polarized and electric shutter-type stereo imaging systems, the former was found to be superior in terms of both accuracy and speed for knot-tying and for the loop pass test. The results of our experiments show that the proposed 3D endoscopic system has a sufficiently wide viewing angle and zone for multi-viewing, and that it provides better image quality and more stable optical performance compared with the electric shutter-type.

Adjustable-Viewing-Angle Endoscopic Tool for Skull Base and Brain Surgery

NASA Technical Reports Server (NTRS)

Bae, Youngsam; Liao, Anna; Manohara, Harish; Shahinian, Hrayr

2008-01-01

The term Multi-Angle and Rear Viewing Endoscopic tooL (MARVEL) denotes an auxiliary endoscope, now undergoing development, that a surgeon would use in conjunction with a conventional endoscope to obtain additional perspective. The role of the MARVEL in endoscopic brain surgery would be similar to the role of a mouth mirror in dentistry. Such a tool is potentially useful for in-situ planetary geology applications for the close-up imaging of unexposed rock surfaces in cracks or those not in the direct line of sight. A conventional endoscope provides mostly a frontal view that is, a view along its longitudinal axis and, hence, along a straight line extending from an opening through which it is inserted. The MARVEL could be inserted through the same opening as that of the conventional endoscope, but could be adjusted to provide a view from almost any desired angle. The MARVEL camera image would be displayed, on the same monitor as that of the conventional endoscopic image, as an inset within the conventional endoscopic image. For example, while viewing a tumor from the front in the conventional endoscopic image, the surgeon could simultaneously view the tumor from the side or the rear in the MARVEL image, and could thereby gain additional visual cues that would aid in precise three-dimensional positioning of surgical tools to excise the tumor. Indeed, a side or rear view through the MARVEL could be essential in a case in which the object of surgical interest was not visible from the front. The conceptual design of the MARVEL exploits the surgeon s familiarity with endoscopic surgical tools. The MARVEL would include a miniature electronic camera and miniature radio transmitter mounted on the tip of a surgical tool derived from an endo-scissor (see figure). The inclusion of the radio transmitter would eliminate the need for wires, which could interfere with manipulation of this and other surgical tools. The handgrip of the tool would be connected to a linkage similar to that of an endo-scissor, but the linkage would be configured to enable adjustment of the camera angle instead of actuation of a scissor blade. It is envisioned that thicknesses of the tool shaft and the camera would be less than 4 mm, so that the camera-tipped tool could be swiftly inserted and withdrawn through a dime-size opening. Electronic cameras having dimensions of the order of millimeters are already commercially available, but their designs are not optimized for use in endoscopic brain surgery. The variety of potential endoscopic, thoracoscopic, and laparoscopic applications can be expected to increase as further development of electronic cameras yields further miniaturization and improvements in imaging performance.

3D-printed phantom for the characterization of non-uniform rotational distortion (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hohert, Geoffrey; Pahlevaninezhad, Hamid; Lee, Anthony; Lane, Pierre M.

2016-03-01

Endoscopic catheter-based imaging systems that employ a 2-dimensional rotary or 3-dimensional rotary-pullback scanning mechanism require constant angular velocity at the distal tip to ensure correct angular registration of the collected signal. Non-uniform rotational distortion (NURD) - often present due to a variety of mechanical issues - can result in inconsistent position and velocity profiles at the tip, limiting the accuracy of any measurements. Since artifacts like NURD are difficult to identify and characterize during tissue imaging, phantoms with well-defined patterns have been used to quantify position and/or velocity error. In this work we present a fast, versatile, and cost-effective method for making fused deposition modeling 3D printed phantoms for identifying and quantifying NURD errors along an arbitrary user-defined pullback path. Eight evenly-spaced features are present at the same orientation at all points on the path such that deviations from expected geometry can be quantified for the imaging catheter. The features are printed vertically and then folded together around the path to avoid issues with printer head resolution. This method can be adapted for probes of various diameters and for complex imaging paths with multiple bends. We demonstrate imaging using the 3D printed phantoms with a 1mm diameter rotary-pullback OCT catheter and system as a means of objectively evaluating the mechanical performance of similarly constructed probes.

Enhanced differential evolution to combine optical mouse sensor with image structural patches for robust endoscopic navigation.

PubMed

Luo, Xiongbiao; Jayarathne, Uditha L; McLeod, A Jonathan; Mori, Kensaku

2014-01-01

Endoscopic navigation generally integrates different modalities of sensory information in order to continuously locate an endoscope relative to suspicious tissues in the body during interventions. Current electromagnetic tracking techniques for endoscopic navigation have limited accuracy due to tissue deformation and magnetic field distortion. To avoid these limitations and improve the endoscopic localization accuracy, this paper proposes a new endoscopic navigation framework that uses an optical mouse sensor to measure the endoscope movements along its viewing direction. We then enhance the differential evolution algorithm by modifying its mutation operation. Based on the enhanced differential evolution method, these movement measurements and image structural patches in endoscopic videos are fused to accurately determine the endoscope position. An evaluation on a dynamic phantom demonstrated that our method provides a more accurate navigation framework. Compared to state-of-the-art methods, it improved the navigation accuracy from 2.4 to 1.6 mm and reduced the processing time from 2.8 to 0.9 seconds.

Image segmentation of pyramid style identifier based on Support Vector Machine for colorectal endoscopic images.

PubMed

Okamoto, Takumi; Koide, Tetsushi; Sugi, Koki; Shimizu, Tatsuya; Anh-Tuan Hoang; Tamaki, Toru; Raytchev, Bisser; Kaneda, Kazufumi; Kominami, Yoko; Yoshida, Shigeto; Mieno, Hiroshi; Tanaka, Shinji

2015-08-01

With the increase of colorectal cancer patients in recent years, the needs of quantitative evaluation of colorectal cancer are increased, and the computer-aided diagnosis (CAD) system which supports doctor's diagnosis is essential. In this paper, a hardware design of type identification module in CAD system for colorectal endoscopic images with narrow band imaging (NBI) magnification is proposed for real-time processing of full high definition image (1920 × 1080 pixel). A pyramid style image segmentation with SVMs for multi-size scan windows, which can be implemented on an FPGA with small circuit area and achieve high accuracy, is proposed for actual complex colorectal endoscopic images.

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

PubMed

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.

A high definition Mueller polarimetric endoscope for tissue characterisation

NASA Astrophysics Data System (ADS)

Qi, Ji; Elson, Daniel S.

2016-05-01

The contrast mechanism of medical endoscopy is mainly based on metrics of optical intensity and wavelength. As another fundamental property of light, polarization can not only reveal tissue scattering and absorption information from a different perspective, but can also provide insight into directional tissue birefringence properties to monitor pathological changes in collagen and elastin. Here we demonstrate a low cost wide field high definition Mueller polarimetric endoscope with minimal alterations to a rigid endoscope. We show that this novel endoscopic imaging modality is able to provide a number of image contrast mechanisms besides traditional unpolarized radiation intensity, including linear depolarization, circular depolarization, cross-polarization, directional birefringence and dichroism. This enhances tissue features of interest, and additionally reveals tissue micro-structure and composition, which is of central importance for tissue diagnosis and image guidance for surgery. The potential applications of the Mueller polarimetric endoscope include wide field early epithelial cancer diagnosis, surgical margin detection and energy-based tissue fusion monitoring, and could further benefit a wide range of endoscopic investigations through intra-operative guidance.

Endoscopic ultrasound

MedlinePlus

... page: //medlineplus.gov/ency/article/007646.htm Endoscopic ultrasound To use the sharing features on this page, please enable JavaScript. Endoscopic ultrasound is a type of imaging test. It is ...

Design of an autofocus capsule endoscope system and the corresponding 3D reconstruction algorithm.

PubMed

Zhang, Wei; Jin, Yi-Tao; Guo, Xin; Su, Jin-Hui; You, Su-Ping

2016-10-01

A traditional capsule endoscope can only take 2D images, and most of the images are not clear enough to be used for diagnosing. A 3D capsule endoscope can help doctors make a quicker and more accurate diagnosis. However, blurred images negatively affect reconstruction accuracy. A compact, autofocus capsule endoscope system is designed in this study. Using a liquid lens, the system can be electronically controlled to autofocus, and without any moving elements. The depth of field of the system is in the 3-100 mm range and its field of view is about 110°. The images captured by this optical system are much clearer than those taken by a traditional capsule endoscope. A 3D reconstruction algorithm is presented to adapt to the zooming function of our proposed system. Simulations and experiments have shown that more feature points can be correctly matched and a higher reconstruction accuracy can be achieved by this strategy.

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

NASA Astrophysics Data System (ADS)

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.

Intraoperative Ultrasound to Assess for Pancreatic Duct Injuries

DTIC Science & Technology

2015-04-01

cholecystocholangiopancreatography is often nondiagnostic, gastroenterologists may not be available for endoscopic retrograde cholangiopancreatography (ERCP...10MHz.We use the SonoSite MicroMaxx SLT 10-5 MHz 52mm broadband linear array intraoperative US probe ( FUJIFILM SonoSite, Inc., Bothell, WA). The duct...Intraoperative US Availability Is gastroenterology available? Is the fluoroscopic and endoscopic equipment available? Is MRCP available? Is a

Endoscopic near-infrared dental imaging with indocyanine green: a pilot study.

PubMed

Li, Zhongqiang; Yao, Shaomian; Xu, Jian; Wu, Ye; Li, Chunhong; He, Ziying

2018-06-01

Current dental diagnosis, especially tooth abnormalities, relies largely on X-ray-based imaging, a technique that requires specialized skills and suffers from ionizing radiation. Here, we present a pilot study in rats of an efficient, ionizing-radiation-free and easy-to-use alternative for dental imaging. Postnatal rats at different ages were injected with indocyanine green and molars were imaged by a laboratory-designed endoscopic near-infrared (NIR) dental imaging system. The results indicate that the endoscopic NIR dental imaging can be used to observe the morphology of postnatal rat molars, especially at early postnatal stages when morphology of the molar is indistinguishable under visible conditions. A small abnormal cusp was observed and distinguished from the normal cusps by the NIR dental imaging system. Dental structures, such as unerupted molars, can be imaged as soon as 10 min after the injection of indocyanine green; imaging after 24 h shows improved imaging contrast. Overall, the endoscopic NIR fluorescence dental imaging system described here may be useful in dental research; this technique may serve as a safe, real-time imaging tool for dental diagnosis and treatment beyond experimental systems in the future. © 2018 New York Academy of Sciences.

Rendering-based video-CT registration with physical constraints for image-guided endoscopic sinus surgery

NASA Astrophysics Data System (ADS)

Otake, Y.; Leonard, S.; Reiter, A.; Rajan, P.; Siewerdsen, J. H.; Ishii, M.; Taylor, R. H.; Hager, G. D.

2015-03-01

We present a system for registering the coordinate frame of an endoscope to pre- or intra- operatively acquired CT data based on optimizing the similarity metric between an endoscopic image and an image predicted via rendering of CT. Our method is robust and semi-automatic because it takes account of physical constraints, specifically, collisions between the endoscope and the anatomy, to initialize and constrain the search. The proposed optimization method is based on a stochastic optimization algorithm that evaluates a large number of similarity metric functions in parallel on a graphics processing unit. Images from a cadaver and a patient were used for evaluation. The registration error was 0.83 mm and 1.97 mm for cadaver and patient images respectively. The average registration time for 60 trials was 4.4 seconds. The patient study demonstrated robustness of the proposed algorithm against a moderate anatomical deformation.

Intra-operative registration for image enhanced endoscopic sinus surgery using photo-consistency.

PubMed

Chen, Min Si; Gonzalez, Gerardo; Lapeer, Rudy

2007-01-01

The purpose of this paper is to present an intensity based algorithm for aligning 2D endoscopic images with virtual images generated from pre-operative 3D data. The proposed algorithm uses photo-consistency as the measurement of similarity between images, provided the illumination is independent from the viewing direction.

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

PubMed

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.

Robust feature tracking for endoscopic pose estimation and structure recovery

NASA Astrophysics Data System (ADS)

Speidel, S.; Krappe, S.; Röhl, S.; Bodenstedt, S.; Müller-Stich, B.; Dillmann, R.

2013-03-01

Minimally invasive surgery is a highly complex medical discipline with several difficulties for the surgeon. To alleviate these difficulties, augmented reality can be used for intraoperative assistance. For visualization, the endoscope pose must be known which can be acquired with a SLAM (Simultaneous Localization and Mapping) approach using the endoscopic images. In this paper we focus on feature tracking for SLAM in minimally invasive surgery. Robust feature tracking and minimization of false correspondences is crucial for localizing the endoscope. As sensory input we use a stereo endoscope and evaluate different feature types in a developed SLAM framework. The accuracy of the endoscope pose estimation is validated with synthetic and ex vivo data. Furthermore we test the approach with in vivo image sequences from da Vinci interventions.

Automatic localization of endoscope in intraoperative CT image: A simple approach to augmented reality guidance in laparoscopic surgery.

PubMed

Bernhardt, Sylvain; Nicolau, Stéphane A; Agnus, Vincent; Soler, Luc; Doignon, Christophe; Marescaux, Jacques

2016-05-01

The use of augmented reality in minimally invasive surgery has been the subject of much research for more than a decade. The endoscopic view of the surgical scene is typically augmented with a 3D model extracted from a preoperative acquisition. However, the organs of interest often present major changes in shape and location because of the pneumoperitoneum and patient displacement. There have been numerous attempts to compensate for this distortion between the pre- and intraoperative states. Some have attempted to recover the visible surface of the organ through image analysis and register it to the preoperative data, but this has proven insufficiently robust and may be problematic with large organs. A second approach is to introduce an intraoperative 3D imaging system as a transition. Hybrid operating rooms are becoming more and more popular, so this seems to be a viable solution, but current techniques require yet another external and constraining piece of apparatus such as an optical tracking system to determine the relationship between the intraoperative images and the endoscopic view. In this article, we propose a new approach to automatically register the reconstruction from an intraoperative CT acquisition with the static endoscopic view, by locating the endoscope tip in the volume data. We first describe our method to localize the endoscope orientation in the intraoperative image using standard image processing algorithms. Secondly, we highlight that the axis of the endoscope needs a specific calibration process to ensure proper registration accuracy. In the last section, we present quantitative and qualitative results proving the feasibility and the clinical potential of our approach. Copyright © 2016 Elsevier B.V. All rights reserved.

Vital-dye enhanced fluorescence imaging of gastrointestinal mucosa: metaplasia, neoplasia, inflammation

PubMed Central

Muldoon, Timothy J; Polydorides, Alexandros D; Maru, Dipen M; Harpaz, Noam; Harris, Michael T; Hofstettor, Wayne; Hiotis, Spiros P; Kim, Sanghyun A; Ky, Alex J; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca

2012-01-01

Background Confocal endomicroscopy has revolutionized endoscopy by offering sub-cellular images of gastrointestinal epithelium; however, field-of-view is limited. There is a need for multi-scale endoscopy platforms that use widefield imaging to better direct placement of high-resolution probes. Design Feasibility Study Objective This study evaluates the feasibility of a single agent, proflavine hemisulfate, as a contrast medium during both widefield and high resolution imaging to characterize morphologic changes associated with a variety of gastrointestinal conditions. Setting U.T. M.D. Anderson Cancer Center (Houston, TX) and Mount Sinai Medical Center (New York, NY) Patients, Interventions, and Main Outcome Measurements Surgical specimens were obtained from 15 patients undergoing esophagectomy/colectomy. Proflavine, a vital fluorescent dye, was applied topically. Specimens were imaged with a widefield multispectral microscope and a high-resolution microendoscope. Images were compared to histopathology. Results Widefield-fluorescence imaging enhanced visualization of morphology, including the presence and spatial distribution of glands, glandular distortion, atrophy and crowding. High-resolution imaging of widefield-abnormal areas revealed that neoplastic progression corresponded to glandular heterogeneity and nuclear crowding in dysplasia, with glandular effacement in carcinoma. These widefield and high-resolution image features correlated well with histopathology. Limitations This imaging approach must be validated in vivo with a larger sample size. Conclusions Multi-scale proflavine-enhanced fluorescence imaging can delineate epithelial changes in a variety of gastrointestinal conditions. Distorted glandular features seen with widefield imaging could serve as a critical ‘bridge’ to high-resolution probe placement. An endoscopic platform combining the two modalities with a single vital-dye may facilitate point-of-care decision-making by providing real-time, in vivo diagnoses. PMID:22301343

Vital-dye enhanced fluorescence imaging of GI mucosa: metaplasia, neoplasia, inflammation.

PubMed

Thekkek, Nadhi; Muldoon, Timothy; Polydorides, Alexandros D; Maru, Dipen M; Harpaz, Noam; Harris, Michael T; Hofstettor, Wayne; Hiotis, Spiros P; Kim, Sanghyun A; Ky, Alex Jenny; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca

2012-04-01

Confocal endomicroscopy has revolutionized endoscopy by offering subcellular images of the GI epithelium; however, the field of view is limited. Multiscale endoscopy platforms that use widefield imaging are needed to better direct the placement of high-resolution probes. Feasibility study. This study evaluated the feasibility of a single agent, proflavine hemisulfate, as a contrast medium during both widefield and high-resolution imaging to characterize the morphologic changes associated with a variety of GI conditions. The University of Texas MD Anderson Cancer Center, Houston, Texas, and Mount Sinai Medical Center, New York, New York. PATIENTS, INTERVENTIONS, AND MAIN OUTCOME MEASUREMENTS: Resected specimens were obtained from 15 patients undergoing EMR, esophagectomy, or colectomy. Proflavine hemisulfate, a vital fluorescent dye, was applied topically. The specimens were imaged with a widefield multispectral microscope and a high-resolution microendoscope. The images were compared with histopathologic examination. Widefield fluorescence imaging enhanced visualization of morphology, including the presence and spatial distribution of glands, glandular distortion, atrophy, and crowding. High-resolution imaging of widefield abnormal areas revealed that neoplastic progression corresponded to glandular heterogeneity and nuclear crowding in dysplasia, with glandular effacement in carcinoma. These widefield and high-resolution image features correlated well with the histopathologic features. This imaging approach must be validated in vivo with a larger sample size. Multiscale proflavine-enhanced fluorescence imaging can delineate epithelial changes in a variety of GI conditions. Distorted glandular features seen with widefield imaging could serve as a critical bridge to high-resolution probe placement. An endoscopic platform combining the two modalities with a single vital dye may facilitate point-of-care decision making by providing real-time, in vivo diagnoses. Copyright © 2012 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Linked color imaging application for improving the endoscopic diagnosis accuracy: a pilot study.

PubMed

Sun, Xiaotian; Dong, Tenghui; Bi, Yiliang; Min, Min; Shen, Wei; Xu, Yang; Liu, Yan

2016-09-19

Endoscopy has been widely used in diagnosing gastrointestinal mucosal lesions. However, there are still lack of objective endoscopic criteria. Linked color imaging (LCI) is newly developed endoscopic technique which enhances color contrast. Thus, we investigated the clinical application of LCI and further analyzed pixel brightness for RGB color model. All the lesions were observed by white light endoscopy (WLE), LCI and blue laser imaging (BLI). Matlab software was used to calculate pixel brightness for red (R), green (G) and blue color (B). Of the endoscopic images for lesions, LCI had significantly higher R compared with BLI but higher G compared with WLE (all P < 0.05). R/(G + B) was significantly different among 3 techniques and qualified as a composite LCI marker. Our correlation analysis of endoscopic diagnosis with pathology revealed that LCI was quite consistent with pathological diagnosis (P = 0.000) and the color could predict certain kinds of lesions. ROC curve demonstrated at the cutoff of R/(G+B) = 0.646, the area under curve was 0.646, and the sensitivity and specificity was 0.514 and 0.773. Taken together, LCI could improve efficiency and accuracy of diagnosing gastrointestinal mucosal lesions and benefit target biopsy. R/(G + B) based on pixel brightness may be introduced as a objective criterion for evaluating endoscopic images.

Improving patient and user safety during endoscopic investigation of the pancreatic and biliary ducts

NASA Astrophysics Data System (ADS)

Chandler, John E.; Melville, C. David; Lee, Cameron M.; Saunders, Michael D.; Burkhardt, Matthew R.; Seibel, Eric J.

2011-03-01

Endoscopic investigation of the main pancreatic duct and biliary ducts is called endoscopic retrograde cholangiopancreatography (ERCP), and carries a risk of pancreatitis for the patient. During ERCP, a metal guidewire is inserted into the pancreatobiliary duct from a side-viewing large endoscope within the duodenum. To verify correct placement of the ERCP guidewire, an injection of radiopaque dye is required for fluoroscopic imaging, which exposes the patient and clinical team to x-ray radiation. A safer and more effective means to access the pancreatobiliary system can use direct optical imaging, although the endoscope diameter and stiffness will be significantly larger than a guidewire's. To quantify this invasiveness before human testing, a synthetic force-sensing pancreas was fabricated and attached to an ERCP training model. The invasiveness of a new, 1.7-mm diameter, steerable scanning fiber endoscope (SFE) was compared to the standard ERCP guidewire of 0.89-mm (0.035") diameter that is not steerable. Although twice as large and significantly stiffer than the ERCP guidewire, the SFE generated lower or significantly less average force during insertion at all 4 sensor locations (P<0.05) within the main pancreatic duct. Therefore, the addition of steering and forward visualization at the tip of the endoscope reduced the invasiveness of the in vitro ERCP procedure. Since fluoroscopy is not required, risks associated with dye injection and x-ray exposure can be eliminated when using direct optical visualization. Finally, the SFE provides wide-field high resolution imaging for image-guided interventions, laser-based fluorescence biomarker imaging, and spot spectral analysis for future optical biopsy.

Three-Dimensional Photoacoustic Endoscopic Imaging of the Rabbit Esophagus

PubMed Central

Yao, Junjie; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

2015-01-01

We report photoacoustic and ultrasonic endoscopic images of two intact rabbit esophagi. To investigate the esophageal lumen structure and microvasculature, we performed in vivo and ex vivo imaging studies using a 3.8-mm diameter photoacoustic endoscope and correlated the images with histology. Several interesting anatomic structures were newly found in both the in vivo and ex vivo images, which demonstrates the potential clinical utility of this endoscopic imaging modality. In the ex vivo imaging experiment, we acquired high-resolution motion-artifact-free three-dimensional photoacoustic images of the vasculatures distributed in the walls of the esophagi and extending to the neighboring mediastinal regions. Blood vessels with apparent diameters as small as 190 μm were resolved. Moreover, by taking advantage of the dual-mode high-resolution photoacoustic and ultrasound endoscopy, we could better identify and characterize the anatomic structures of the esophageal lumen, such as the mucosal and submucosal layers in the esophageal wall, and an esophageal branch of the thoracic aorta. In this paper, we present the first photoacoustic images showing the vasculature of a vertebrate esophagus and discuss the potential clinical applications and future development of photoacoustic endoscopy. PMID:25874640

Three-dimensional photoacoustic endoscopic imaging of the rabbit esophagus.

PubMed

Yang, Joon Mo; Favazza, Christopher; Yao, Junjie; Chen, Ruimin; Zhou, Qifa; Shung, K Kirk; Wang, Lihong V

2015-01-01

We report photoacoustic and ultrasonic endoscopic images of two intact rabbit esophagi. To investigate the esophageal lumen structure and microvasculature, we performed in vivo and ex vivo imaging studies using a 3.8-mm diameter photoacoustic endoscope and correlated the images with histology. Several interesting anatomic structures were newly found in both the in vivo and ex vivo images, which demonstrates the potential clinical utility of this endoscopic imaging modality. In the ex vivo imaging experiment, we acquired high-resolution motion-artifact-free three-dimensional photoacoustic images of the vasculatures distributed in the walls of the esophagi and extending to the neighboring mediastinal regions. Blood vessels with apparent diameters as small as 190 μm were resolved. Moreover, by taking advantage of the dual-mode high-resolution photoacoustic and ultrasound endoscopy, we could better identify and characterize the anatomic structures of the esophageal lumen, such as the mucosal and submucosal layers in the esophageal wall, and an esophageal branch of the thoracic aorta. In this paper, we present the first photoacoustic images showing the vasculature of a vertebrate esophagus and discuss the potential clinical applications and future development of photoacoustic endoscopy.

Reevaluation of JPEG image compression to digitalized gastrointestinal endoscopic color images: a pilot study

NASA Astrophysics Data System (ADS)

Kim, Christopher Y.

1999-05-01

Endoscopic images p lay an important role in describing many gastrointestinal (GI) disorders. The field of radiology has been on the leading edge of creating, archiving and transmitting digital images. With the advent of digital videoendoscopy, endoscopists now have the ability to generate images for storage and transmission. X-rays can be compressed 30-40X without appreciable decline in quality. We reported results of a pilot study using JPEG compression of 24-bit color endoscopic images. For that study, the result indicated that adequate compression ratios vary according to the lesion and that images could be compressed to between 31- and 99-fold smaller than the original size without an appreciable decline in quality. The purpose of this study was to expand upon the methodology of the previous sty with an eye towards application for the WWW, a medium which would expand both clinical and educational purposes of color medical imags. The results indicate that endoscopists are able to tolerate very significant compression of endoscopic images without loss of clinical image quality. This finding suggests that even 1 MB color images can be compressed to well under 30KB, which is considered a maximal tolerable image size for downloading on the WWW.

Augmented reality image guidance for minimally invasive coronary artery bypass

NASA Astrophysics Data System (ADS)

Figl, Michael; Rueckert, Daniel; Hawkes, David; Casula, Roberto; Hu, Mingxing; Pedro, Ose; Zhang, Dong Ping; Penney, Graeme; Bello, Fernando; Edwards, Philip

2008-03-01

We propose a novel system for image guidance in totally endoscopic coronary artery bypass (TECAB). A key requirement is the availability of 2D-3D registration techniques that can deal with non-rigid motion and deformation. Image guidance for TECAB is mainly required before the mechanical stabilization of the heart, thus the most dominant source of non-rigid deformation is the motion of the beating heart. To augment the images in the endoscope of the da Vinci robot, we have to find the transformation from the coordinate system of the preoperative imaging modality to the system of the endoscopic cameras. In a first step we build a 4D motion model of the beating heart. Intraoperatively we can use the ECG or video processing to determine the phase of the cardiac cycle. We can then take the heart surface from the motion model and register it to the stereo-endoscopic images of the da Vinci robot using 2D-3D registration methods. We are investigating robust feature tracking and intensity-based methods for this purpose. Images of the vessels available in the preoperative coordinate system can then be transformed to the camera system and projected into the calibrated endoscope view using two video mixers with chroma keying. It is hoped that the augmented view can improve the efficiency of TECAB surgery and reduce the conversion rate to more conventional procedures.

Using optical coherence tomography to detect bacterial biofilms on foley catheters (Conference Presentation)

NASA Astrophysics Data System (ADS)

Heidari, Andrew E.; Oh, Kyungjin; Chen, Zhongping

2017-02-01

Urinary tract infections(UTI) pose a serious problem for hospital patients accounting for 33% of all hospital acquired(nosocomial) infections with indwelling foley catheters. The presence of an indwelling foley catheter provides a scaffolding for circulating planktonic bacteria to adhere to and to form microbial biofilm communities that would typically be hindered by the body's innate immune system response. It is these biofilm communities that form on the inner lumen of foley catheters that provide a reservoir of pathogenic bacteria that could dislodge or disperse from the biofilm and infect urethra or bladder mucosal tissue in the urinary tract. Current diagnostic techniques of urine microbiological cultures are lacking in differentiating asymptomatic bacteriuria and symptomatic catheter-associated urinary tract infection(CAUTI) since almost all patients with chronic indwelling catheters are almost universally bacteriuruic. There is an unmet need of a diagnostic tool to assess the difference between the pathogenesis of asymptomatic bacteriuria and CAUTI, specifically at the site of the native biofilm formation. Optical Coherence Tomography(OCT) is an emerging high resolution, minimally invasive tomographic imaging technique that has shown promise in imaging biofilm structures previously in an endoscopic setting of the airway in-vivo and in microfluidic chambers. OCT can be adapted to image various sized biological surfaces and orifices such as airway branches and blood vessels by using a variety of minature endoscopic probes. In this work OCT will be used to image biofilm structure in-vitro on the inner lumen of extravasated critical care patient's foley catheters. Scanning electron microscopy will be conducted post OCT to confirm the presence of bacterial biofilm in OCT images.

Experimental assessment of a 3-D plenoptic endoscopic imaging system.

PubMed

Le, Hanh N D; Decker, Ryan; Krieger, Axel; Kang, Jin U

2017-01-01

An endoscopic imaging system using a plenoptic technique to reconstruct 3-D information is demonstrated and analyzed in this Letter. The proposed setup integrates a clinical surgical endoscope with a plenoptic camera to achieve a depth accuracy error of about 1 mm and a precision error of about 2 mm, within a 25 mm × 25 mm field of view, operating at 11 frames per second.

Experimental assessment of a 3-D plenoptic endoscopic imaging system

PubMed Central

Le, Hanh N. D.; Decker, Ryan; Krieger, Axel; Kang, Jin U.

2017-01-01

An endoscopic imaging system using a plenoptic technique to reconstruct 3-D information is demonstrated and analyzed in this Letter. The proposed setup integrates a clinical surgical endoscope with a plenoptic camera to achieve a depth accuracy error of about 1 mm and a precision error of about 2 mm, within a 25 mm × 25 mm field of view, operating at 11 frames per second. PMID:29449863

Ultra-high definition (8K UHD) endoscope: our first clinical success.

PubMed

Yamashita, Hiromasa; Aoki, Hisae; Tanioka, Kenkichi; Mori, Toshiyuki; Chiba, Toshio

2016-01-01

We have started clinical application of 8K ultra-high definition (UHD; 7680 × 4320 pixels) imaging technology, which is a 16-fold higher resolution than the current 2K high-definition (HD; 1920 × 1080 pixels) technology, to an endoscope for advanced laparoscopic surgery. Based on preliminary testing experience and with subsequent technical and system improvements, we then proceeded to perform two cases of cholecystectomy and were able to achieve clinical success with an 8K UHD endoscopic system, which consisted of an 8K camera, a 30-degrees angled rigid endoscope with a lens adapter, a pair of 300-W xenon light sources, an 85-inch 8K LCD and an 8K video recorder. These experimental and clinical studies revealed the engineering and clinical feasibility of the 8K UHD endoscope, enabling us to have a positive outlook on its prospective use in clinical practice. The 8K UHD endoscopy promises to open up new possibilities for intricate procedures including anastomoses of thin nerves and blood vessels as well as more confident surgical resections of a diversity of cancer tissues. 8K endoscopic imaging, compared to imaging by the current 2K imaging technology, is very likely to lead to major changes in the future of medical practice.

Adaptive marker-free registration using a multiple point strategy for real-time and robust endoscope electromagnetic navigation.

PubMed

Luo, Xiongbiao; Wan, Ying; He, Xiangjian; Mori, Kensaku

2015-02-01

Registration of pre-clinical images to physical space is indispensable for computer-assisted endoscopic interventions in operating rooms. Electromagnetically navigated endoscopic interventions are increasingly performed at current diagnoses and treatments. Such interventions use an electromagnetic tracker with a miniature sensor that is usually attached at an endoscope distal tip to real time track endoscope movements in a pre-clinical image space. Spatial alignment between the electromagnetic tracker (or sensor) and pre-clinical images must be performed to navigate the endoscope to target regions. This paper proposes an adaptive marker-free registration method that uses a multiple point selection strategy. This method seeks to address an assumption that the endoscope is operated along the centerline of an intraluminal organ which is easily violated during interventions. We introduce an adaptive strategy that generates multiple points in terms of sensor measurements and endoscope tip center calibration. From these generated points, we adaptively choose the optimal point, which is the closest to its assigned the centerline of the hollow organ, to perform registration. The experimental results demonstrate that our proposed adaptive strategy significantly reduced the target registration error from 5.32 to 2.59 mm in static phantoms validation, as well as from at least 7.58 mm to 4.71 mm in dynamic phantom validation compared to current available methods. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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

PubMed

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.

Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope

NASA Astrophysics Data System (ADS)

Wall, R. Andrew; Barton, Jennifer K.

2012-02-01

A side-viewing, 2 mm diameter, surface magnifying chromoendoscopy (SMC)-optical coherence tomography (OCT) endoscope has been designed for simultaneous, non-destructive surface fluorescence visualization and cross-sectional imaging. We apply this endoscope to in vivo examination of mouse colon. A 30,000 element fiber bundle is combined with single mode fibers. The distal optics consist of a gradient-index lens and spacer to provide a magnification of 1 at a working distance of 1.58 mm in air, necessary to image the sample through a 0.23 mm thick outer glass envelope, and an aluminized right-angle prism fixed to the distal end of the GRIN lens assembly. The resulting 1:1 imaging system is capable of 3.9 μm lateral and 2.3 μm axial resolution in the OCT channel, and 125 lp/mm resolution across a 0.70 mm field of view in the SMC channel. The endoscope can perform high contrast crypt visualization, molecular imaging, and cross-sectional imaging of colon microstructure.

Cascaded deep decision networks for classification of endoscopic images

NASA Astrophysics Data System (ADS)

Murthy, Venkatesh N.; Singh, Vivek; Sun, Shanhui; Bhattacharya, Subhabrata; Chen, Terrence; Comaniciu, Dorin

2017-02-01

Both traditional and wireless capsule endoscopes can generate tens of thousands of images for each patient. It is desirable to have the majority of irrelevant images filtered out by automatic algorithms during an offline review process or to have automatic indication for highly suspicious areas during an online guidance. This also applies to the newly invented endomicroscopy, where online indication of tumor classification plays a significant role. Image classification is a standard pattern recognition problem and is well studied in the literature. However, performance on the challenging endoscopic images still has room for improvement. In this paper, we present a novel Cascaded Deep Decision Network (CDDN) to improve image classification performance over standard Deep neural network based methods. During the learning phase, CDDN automatically builds a network which discards samples that are classified with high confidence scores by a previously trained network and concentrates only on the challenging samples which would be handled by the subsequent expert shallow networks. We validate CDDN using two different types of endoscopic imaging, which includes a polyp classification dataset and a tumor classification dataset. From both datasets we show that CDDN can outperform other methods by about 10%. In addition, CDDN can also be applied to other image classification problems.

Novel Multisensor Probe for Monitoring Bladder Temperature During Locoregional Chemohyperthermia for Nonmuscle-Invasive Bladder Cancer: Technical Feasibility Study

PubMed Central

Geijsen, Debby E.; Zum Vörde Sive Vörding, Paul J.; Schooneveldt, Gerben; Sijbrands, Jan; Hulshof, Maarten C.; de la Rosette, Jean; de Reijke, Theo M.; Crezee, Hans

2013-01-01

Abstract Background and Purpose: The effectiveness of locoregional hyperthermia combined with intravesical instillation of mitomycin C to reduce the risk of recurrence and progression of intermediate- and high-risk nonmuscle-invasive bladder cancer is currently investigated in clinical trials. Clinically effective locoregional hyperthermia delivery necessitates adequate thermal dosimetry; thus, optimal thermometry methods are needed to monitor accurately the temperature distribution throughout the bladder wall. The aim of the study was to evaluate the technical feasibility of a novel intravesical device (multi-sensor probe) developed to monitor the local bladder wall temperatures during loco-regional C-HT. Materials and Methods: A multisensor thermocouple probe was designed for deployment in the human bladder, using special sensors to cover the bladder wall in different directions. The deployment of the thermocouples against the bladder wall was evaluated with visual, endoscopic, and CT imaging in bladder phantoms, porcine models, and human bladders obtained from obduction for bladder volumes and different deployment sizes of the probe. Finally, porcine bladders were embedded in a phantom and subjected to locoregional heating to compare probe temperatures with additional thermometry inside and outside the bladder wall. Results: The 7.5 cm thermocouple probe yielded optimal bladder wall contact, adapting to different bladder volumes. Temperature monitoring was shown to be accurate and representative for the actual bladder wall temperature. Conclusions: Use of this novel multisensor probe could yield a more accurate monitoring of the bladder wall temperature during locoregional chemohyperthermia. PMID:24112045

Doppler endoscopic probe as a guide to risk stratification and definitive hemostasis of peptic ulcer bleeding.

PubMed

Jensen, Dennis M; Ohning, Gordon V; Kovacs, Thomas O G; Ghassemi, Kevin A; Jutabha, Rome; Dulai, Gareth S; Machicado, Gustavo A

2016-01-01

For more than 4 decades endoscopists have relied on ulcer stigmata for risk stratification and as a guide to hemostasis. None used arterial blood flow underneath stigmata to predict outcomes. For patients with severe peptic ulcer bleeding (PUB), we used a Doppler endoscopic probe (DEP) for (1) detection of blood flow underlying stigmata of recent hemorrhage (SRH), (2) quantitating rates of residual arterial blood flow under SRH after visually directed standard endoscopic treatment, and (3) comparing risks of rebleeding and actual 30-day rebleed rates for spurting arterial bleeding (Forrest [F] IA) and oozing bleeding (F IB). Prospective cohort study of 163 consecutive patients with severe PUB and different SRH. All blood flow detected by the DEP was arterial. Detection rates were 87.4% in major SRH-spurting arterial bleeding (F IA), non-bleeding visible vessel (F IIA), clot (F IIB)-and were significantly lower at 42.3% (P < .0001) for an intermediate group of oozing bleeding (F IB) or flat spot (F IIC). For spurting bleeding (F IA) versus oozing (F IB), baseline DEP arterial flow was 100% versus 46.7%, residual blood flow detected after endoscopic hemostasis was 35.7% versus 0%, and 30-day rebleed rates were 28.6% versus 0% (all P < .05). (1) For major SRH versus oozing or spot, the arterial blood flow detection rate by the DEP was significantly higher, indicating a higher rebleed risk. (2) Before and after endoscopic treatment, spurting (F IA) PUB had significantly higher rates of blood flow detection than oozing (F IB) PUB and a significantly higher 30-day rebleed rate. (3) The DEP is recommended as a new endoscopic guide with SRH to improve risk stratification and potentially definitive hemostasis for PUB. Published by Elsevier Inc.

High-frequency ultrasound probe sonography staging for colorectal neoplasia with superficial morphology: its utility and impact on patient management.

PubMed

Urban, Ondrej; Kliment, Martin; Fojtik, Petr; Falt, Premysl; Orhalmi, Julius; Vitek, Petr; Holeczy, Pavol

2011-10-01

This prospective study aimed to evaluate the impact of high-frequency ultrasound probe sonography (HFUPS) staging on the management of patients with superficial colorectal neoplasia (SCN) as determined by the endoscopic characteristics of lesions. Consecutive patients referred for endoscopic treatment of nonpedunculated SCN were enrolled in this study. A lesion was considered high risk if a depressed area or invasive pit pattern was present. The gold standard for final staging included histology from endoscopic or surgical resection. The impact on treatment was defined as any modification of the therapeutic algorithm based on the result of the HFUPS examination compared with that based on endoscopy alone. In this study, 48 lesions in 48 patients were evaluated. Of these, 28 (58%) were considered high risk, and the remaining 20 (42%) were regarded as low risk. A total of seven lesions (15%) that could not be examined with HFUPS and another non-neoplastic lesion were excluded from final analysis. For the remaining 40 lesions, the overall accuracy of the HFUPS examination to predict the correct T-stage was 90% (95% confidence interval [CI], 77-96%). The HFUPS examination had a positive impact on the treatment of 0 low-risk and 11 high-risk (42%) lesions. The impact of HFUPS on the treatment of SCN depends on their endoscopic characteristics. It is negligible for low-risk SCNs, and these lesions can be treated on the basis of their endoscopic appearance alone. Nevertheless, compared with endoscopy alone, HFUPS changed the subsequent therapeutic approach in a positive way for up to 42% of high-risk lesions, including those with a depressed component and an invasive pit pattern. These endoscopic features can therefore be recommended as the entry criteria for an HFUPS examination.

Doppler Endoscopic Probe as a Guide to Risk Stratification and Definitive Hemostasis of Peptic Ulcer Bleeding

PubMed Central

Jensen, Dennis M.; Ohning, Gordon V.; Kovacs, Thomas OG; Ghassemi, Kevin A.; Jutabha, Rome; Dulai, Gareth S.; Machicado, Gustavo A.

2015-01-01

Background and Aims For more than 4 decades endoscopists have relied on ulcer stigmata for risk stratification and as a guide to hemostasis. None used arterial blood flow underneath stigmata to predict outcomes. For patients with severe peptic ulcer bleeding (PUBs), we used Doppler endoscopic probe (DEP) for: 1. detection of blood flow underlying stigmata of recent hemorrhage (SRH), 2. quantitating rates of residual arterial blood flow under SRH after visually directed standard endoscopic treatment, and 3. comparing risks of rebleeding and actual 30 day rebleed rates for spurting arterial bleeding (Forrest – FIA) and oozing bleeding (FIB). Methods Prospective cohort study of 163 consecutive patients with severe PUBs and different SRH. Results All blood flow detected by DEP was arterial. Detection rates were 87.4% in major SRH - spurting arterial bleeding (FIA), non bleeding visible vessel (FIIA), clot (FIIB) - and significantly lower at 42.3% (p<0.0001) for intermediate group of oozing bleeding (FIB) or flat spot (FIIC). For spurting bleeding (FIA) vs. oozing (FIB), baseline DEP arterial flow was 100% vs. 46.7%; residual blood flow detected after endoscopic hemostasis was 35.7% vs. 0%; and 30 day rebleed rates were 28.6% vs. 0% (all p<0.05). Conclusions 1. For major SRH vs. oozing or spot, the arterial blood flow detection rates by DEP was significantly higher, indicating a higher rebleed risk. 2. Before and after endoscopic treatment, spurting FIA PUB’s had significantly higher rates of blood flow detection than oozing FIB PUB’s and a significantly higher 30 rebleed rate. 3. DEP is recommended as a new endoscopic guide with SRH to improve risk stratification and potentially definitive hemostasis for PUBs. PMID:26318834

Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope

NASA Astrophysics Data System (ADS)

Wall, R. Andrew; Barton, Jennifer K.

2012-08-01

A side-viewing, 2.3-mm diameter, surface magnifying chromoendoscopy-optical coherence tomography (SMC-OCT) endoscope has been designed for simultaneous, nondestructive surface fluorescence visualization and cross-sectional imaging. We apply this endoscope to in vivo examination of the mouse colon. A 30,000 element fiber bundle is combined with single mode fibers, for SMC and OCT imaging, respectively. The distal optics consist of a gradient-index lens and spacer to provide a 1× magnification at a working distance of 1.58 mm in air, necessary to image the sample through a 0.23-mm thick outer glass envelope, and an aluminized right-angle prism fixed to the distal end of the gradient-index lens assembly. The resulting 1∶1 imaging system is capable of 3.9-μm lateral and 2.3-μm axial resolution in the OCT channel, and 125-lp/mm resolution across a 0.70-mm field of view in the SMC channel. The endoscope can perform high contrast crypt visualization, molecular imaging, and cross-sectional imaging of colon microstructure.

Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope

PubMed Central

Wall, R. Andrew

2012-01-01

Abstract. A side-viewing, 2.3-mm diameter, surface magnifying chromoendoscopy-optical coherence tomography (SMC-OCT) endoscope has been designed for simultaneous, nondestructive surface fluorescence visualization and cross-sectional imaging. We apply this endoscope to in vivo examination of the mouse colon. A 30,000 element fiber bundle is combined with single mode fibers, for SMC and OCT imaging, respectively. The distal optics consist of a gradient-index lens and spacer to provide a 1× magnification at a working distance of 1.58 mm in air, necessary to image the sample through a 0.23-mm thick outer glass envelope, and an aluminized right-angle prism fixed to the distal end of the gradient-index lens assembly. The resulting 1∶1 imaging system is capable of 3.9-µm lateral and 2.3-µm axial resolution in the OCT channel, and 125-lp/mm resolution across a 0.70-mm field of view in the SMC channel. The endoscope can perform high contrast crypt visualization, molecular imaging, and cross-sectional imaging of colon microstructure. PMID:23224190

Probe-based confocal laser endomicroscopy in the margin delineation of early gastric cancer for endoscopic submucosal dissection.

PubMed

Park, Jun Chul; Park, Yehyun; Kim, Hyun Ki; Jo, Jeong-Hyeon; Park, Chan Hyuk; Kim, Eun Hye; Jung, Da Hyun; Chung, Hyunsoo; Shin, Sung Kwan; Lee, Sang Kil; Lee, Yong Chan

2017-05-01

We evaluated probe-based confocal laser endomicroscopy (pCLE) in the margin delineation of early gastric cancer (EGC) for endoscopic submucosal dissection in comparison with white-light imaging with chromoendoscopy (CE). We conducted a prospective, randomized controlled study from November 2013 to October 2014 in a tertiary referral hospital. A total of 101 patients scheduled for endoscopic submucosal dissection due to differentiated EGC were randomized into pCLE and CE groups (pCLE 51, CE 50). Markings were made by electrocautery at the proximal and distal tumor margins, as determined by either pCLE or CE. The distance from the marking to the tumor margin was measured in the resected specimen histopathologically and was compared between the two groups by a linear mixed model. Among 104 lesions, 80 lesions with 149 markings (pCLE 68, CE 81) were analyzed after excluding undifferentiated EGCs (n = 8) and unidentifiable markings (n = 13). Although the complete resection rate showed no difference between the groups (94.6% vs 93.2%, P = 1.000), the median distance from the marking to the margin was shorter in the pCLE group (1.3 vs 1.8 mm, P = 0.525) and the proportion of the distance <1 mm was higher (43.9% vs 27.6%, P = 0.023) in the pCLE group. Finally, subgroup analysis with superficial flat lesions (18 lesions, 31 marking dots) showed a significantly decreased distance in the pCLE group (0.5 vs 3.1 mm, P = 0.007). Among EGCs with superficial flat morphology, in which the accurate evaluation of lateral extent is difficult with CE, pCLE would be useful for more precise margin delineation. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

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

NASA Astrophysics Data System (ADS)

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.

Optical biopsy on head and neck tissue using full-field OCT: a pilot study

NASA Astrophysics Data System (ADS)

De Leeuw, Frédéric; Latrive, Anne; Casiraghi, Odile; Ferchiou, Malek; Harms, Fabrice; Boccara, Claude; Laplace-Builhé, Corinne

2014-03-01

Here we evaluate the clinical value of Full-Field OCT imaging in the management of patients with Head and Neck cancers by making a reliable histological diagnosis on FFOCT images produced during preoperative procedure. FFOCT performs a true "virtual extemporaneous exam" that we want to compare to the gold standard (extemporaneous and conventional histology with H and E staining). This new optical technology could be useful when diagnosing a lesion, cancerous or precancerous, or at the time of its surgical management. Full-Field Optical Coherence Tomography virtually slices the tissue using white light interferometry to produce in-depth 2D images with an isotropic resolution around 1 micrometer. With such a high resolution FFOCT systems produce "optical biopsy" images that are similar to that obtained with classical histology procedures, but without any staining and in only a few minutes. We imaged freshly excised samples from patients, of mouth, tongue, epiglottis and larynx tissues, both healthy and cancerous. FFOCT images were acquired and later compared with histology of the same samples. Common features were identified and characteristics of each tissue type were matched in order to form an image atlas for pathologist training. We were able to identify indicators of tumors such as heterogeneities in cell distribution, surrounding stroma, anomalous keratinization… In conclusion, FFOCT is a fast, non-invasive, non-destructive imaging tool that can be inserted into the pathology lab workflow and can provide a quick assessment of microscopic tissue architecture and content. Furthermore we are developing a similar system with a rigid endoscopic probe in order to do in vivo and in situ high-resolution imaging. Our probe could thus guide the surgeon in real time before and during excision and ensure a more precise gesture.

Trimodal color-fluorescence-polarization endoscopy aided by a tumor selective molecular probe accurately detects flat lesions in colitis-associated cancer

NASA Astrophysics Data System (ADS)

Charanya, Tauseef; York, Timothy; Bloch, Sharon; Sudlow, Gail; Liang, Kexian; Garcia, Missael; Akers, Walter J.; Rubin, Deborah; Gruev, Viktor; Achilefu, Samuel

2014-12-01

Colitis-associated cancer (CAC) arises from premalignant flat lesions of the colon, which are difficult to detect with current endoscopic screening approaches. We have developed a complementary fluorescence and polarization reporting strategy that combines the unique biochemical and physical properties of dysplasia and cancer for real-time detection of these lesions. Using azoxymethane-dextran sodium sulfate (AOM-DSS) treated mice, which recapitulates human CAC and dysplasia, we show that an octapeptide labeled with a near-infrared (NIR) fluorescent dye selectively identified all precancerous and cancerous lesions. A new thermoresponsive sol-gel formulation allowed topical application of the molecular probe during endoscopy. This method yielded high contrast-to-noise ratios (CNR) between adenomatous tumors (20.6±1.65) and flat lesions (12.1±1.03) and surrounding uninvolved colon tissue versus CNR of inflamed tissues (1.62±0.41). Incorporation of nanowire-filtered polarization imaging into NIR fluorescence endoscopy shows a high depolarization contrast in both adenomatous tumors and flat lesions in CAC, reflecting compromised structural integrity of these tissues. Together, the real-time polarization imaging provides real-time validation of suspicious colon tissue highlighted by molecular fluorescence endoscopy.

Endoscopic image-guided thermal therapy using targeted near infrared fluorescent gold nanorods (Conference Presentation)

NASA Astrophysics Data System (ADS)

Elson, Daniel S.

2016-09-01

We present an in vivo study of endoscopic fluorescence image-guided photothermal therapy of human oesophageal adenocarcinoma in a murine xenograft model, using intratumoural or intravenous gold nanorods functionalised with Cy5.5 and EGFR.

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

PubMed

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 < 0.01). The success rate of ROI selection diminished as the number of separated regions increased. However, separated regions up to 12 with a region size of 160 × 160 pixels were selected with no failure. Surgical tasks on a phantom model and a cadaver were attempted to verify the feasibility in a clinical environment. Hands-free endoscope manipulation without releasing the instruments in hand was achieved. The proposed method requires only a small, low-cost camera and an image processing. The technique enables surgeons to perform solo surgeries without a camera assistant.

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

PubMed

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 rights reserved.

Design of the computerized 3D endoscopic imaging system for delicate endoscopic surgery.

PubMed

Song, Chul-Gyu; Kang, Jin U

2011-02-01

This paper describes a 3D endoscopic video system designed to improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery. In a comparison of the polarized and conventional electric shutter-type stereo imaging systems, the former was found to be superior in terms of both accuracy and speed for suturing and for the loop pass test. Among the groups performing loop passing and suturing, there was no significant difference in the task performance between the 2D and 3D modes, however, suturing was performed 15% (p < 0.05) faster in 3D mode by both groups. The results of our experiments show that the proposed 3D endoscopic system has a sufficiently wide viewing angle and zone for multi-viewing.

3D imaging with a single-aperture 3-mm objective lens: concept, fabrication, and test

NASA Astrophysics Data System (ADS)

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

2011-10-01

There are many advantages to minimally invasive surgery (MIS). An endoscope is the optical system of choice by the surgeon for MIS. The smaller the incision or opening made to perform the surgery, the smaller the optical system needed. For minimally invasive neurological and skull base surgeries the openings are typically 10-mm in diameter (dime sized) or less. The largest outside diameter (OD) endoscope used is 4mm. A significant drawback to endoscopic MIS is that it only provides a monocular view of the surgical site thereby lacking depth information for the surgeon. A stereo view would provide the surgeon instantaneous depth information of the surroundings within the field of view, a significant advantage especially during brain surgery. Providing 3D imaging in an endoscopic objective lens system presents significant challenges because of the tight packaging constraints. This paper presents a promising new technique for endoscopic 3D imaging that uses a single lens system with complementary multi-bandpass filters (CMBFs), and describes the proof-of-concept demonstrations performed to date validating the technique. These demonstrations of the technique have utilized many commercial off-the- shelf (COTS) components including the ones used in the endoscope objective.

Development of the local magnification method for quantitative evaluation of endoscope geometric distortion

NASA Astrophysics Data System (ADS)

Wang, Quanzeng; Cheng, Wei-Chung; Suresh, Nitin; Hua, Hong

2016-05-01

With improved diagnostic capabilities and complex optical designs, endoscopic technologies are advancing. As one of the several important optical performance characteristics, geometric distortion can negatively affect size estimation and feature identification related diagnosis. Therefore, a quantitative and simple distortion evaluation method is imperative for both the endoscopic industry and the medical device regulatory agent. However, no such method is available yet. While the image correction techniques are rather mature, they heavily depend on computational power to process multidimensional image data based on complex mathematical model, i.e., difficult to understand. Some commonly used distortion evaluation methods, such as the picture height distortion (DPH) or radial distortion (DRAD), are either too simple to accurately describe the distortion or subject to the error of deriving a reference image. We developed the basic local magnification (ML) method to evaluate endoscope distortion. Based on the method, we also developed ways to calculate DPH and DRAD. The method overcomes the aforementioned limitations, has clear physical meaning in the whole field of view, and can facilitate lesion size estimation during diagnosis. Most importantly, the method can facilitate endoscopic technology to market and potentially be adopted in an international endoscope standard.

3D Imaging with a Single-Aperture 3-mm Objective Lens: Concept, Fabrication and Test

NASA Technical Reports Server (NTRS)

Korniski, Ron; Bae, Sam Y.; Shearn, Mike; Manohara, Harish; Shahinian, Hrayr

2011-01-01

There are many advantages to minimally invasive surgery (MIS). An endoscope is the optical system of choice by the surgeon for MIS. The smaller the incision or opening made to perform the surgery, the smaller the optical system needed. For minimally invasive neurological and skull base surgeries the openings are typically 10-mm in diameter (dime sized) or less. The largest outside diameter (OD) endoscope used is 4mm. A significant drawback to endoscopic MIS is that it only provides a monocular view of the surgical site thereby lacking depth information for the surgeon. A stereo view would provide the surgeon instantaneous depth information of the surroundings within the field of view, a significant advantage especially during brain surgery. Providing 3D imaging in an endoscopic objective lens system presents significant challenges because of the tight packaging constraints. This paper presents a promising new technique for endoscopic 3D imaging that uses a single lens system with complementary multi-bandpass filters (CMBFs), and describes the proof-of-concept demonstrations performed to date validating the technique. These demonstrations of the technique have utilized many commercial off-the-shelf (COTS) components including the ones used in the endoscope objective.

Quantitative, Noninvasive Imaging of DNA Damage in Vivo of Prostate Cancer Therapy by Transurethral Photoacoustic (TUPA) Imaging

DTIC Science & Technology

2014-10-01

provided the funding to devise a trans-urethral photoacoustic endoscope , which has the potential to obtain higher resolution by using a high frequency...modality. This grant has provided the funding to devise a trans-urethral photoacoustic endoscope , which has the potential to obtain higher resolution by...multimode optical fiber (UM22-600, Thorlabs) was placed which is positioned statically along the axis of the endoscope . A parabolic acoustic

Towards automated visual flexible endoscope navigation.

PubMed

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.

Geometric estimation of intestinal contraction for motion tracking of video capsule endoscope

NASA Astrophysics Data System (ADS)

Mi, Liang; Bao, Guanqun; Pahlavan, Kaveh

2014-03-01

Wireless video capsule endoscope (VCE) provides a noninvasive method to examine the entire gastrointestinal (GI) tract, especially small intestine, where other endoscopic instruments can barely reach. VCE is able to continuously provide clear pictures in short fixed intervals, and as such researchers have attempted to use image processing methods to track the video capsule in order to locate the abnormalities inside the GI tract. To correctly estimate the speed of the motion of the endoscope capsule, the radius of the intestinal track must be known a priori. Physiological factors such as intestinal contraction, however, dynamically change the radius of the small intestine, which could bring large errors in speed estimation. In this paper, we are aiming to estimate the radius of the contracted intestinal track. First a geometric model is presented for estimating the radius of small intestine based on the black hole on endoscopic images. To validate our proposed model, a 3-dimentional virtual testbed that emulates the intestinal contraction is then introduced in details. After measuring the size of the black holes on the test images, we used our model to esimate the radius of the contracted intestinal track. Comparision between analytical results and the emulation model parameters has verified that our proposed method could preciously estimate the radius of the contracted small intestine based on endoscopic images.

Next generation of optical diagnostics for bladder cancer using probe-based confocal laser endomicroscopy

NASA Astrophysics Data System (ADS)

Liu, Jen-Jane; Chang, Timothy C.; Pan, Ying; Hsiao, Shelly T.; Mach, Kathleen E.; Jensen, Kristin C.; Liao, Joseph C.

2012-02-01

Real-time imaging with confocal laser endomicroscopy (CLE) probes that fit in standard endoscopes has emerged as a clinically feasible technology for optical biopsy of bladder cancer. Confocal images of normal, inflammatory, and neoplastic urothelium obtained with intravesical fluorescein can be differentiated by morphologic characteristics. We compiled a confocal atlas of the urinary tract using these diagnostic criteria to be used in a prospective diagnostic accuracy study. Patients scheduled to undergo transurethral resection of bladder tumor underwent white light cystoscopy (WLC), followed by CLE, and histologic confirmation of resected tissue. Areas that appeared normal by WLC were imaged and biopsied as controls. We imaged and prospectively analyzed 135 areas in 57 patients. We show that CLE improves the diagnostic accuracy of WLC for diagnosing benign tissue, low and high grade cancer. Interobserver studies showed a moderate level of agreement by urologists and nonclinical researchers. Despite morphologic differences between inflammation and cancer, real-time differentiation can still be challenging. Identification of bladder cancer-specific contrast agents could provide molecular specificity to CLE. By using fluorescently-labeled antibodies or peptides that bind to proteins expressed in bladder cancer, we have identified putative molecular contrast agents for targeted imaging with CLE. We describe one candidate agent - anti-CD47 - that was instilled into bladder specimens. The tumor and normal urothelium were imaged with CLE, with increased fluorescent signal demonstrated in areas of tumor compared to normal areas. Thus, cancer-specificity can be achieved using molecular contrast agents ex vivo in conjunction with CLE.

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

NASA Astrophysics Data System (ADS)

Venugopal, Vivek; Park, Minho; Ashitate, Yoshitomo; Neacsu, Florin; Kettenring, Frank; Frangioni, John V.; Gangadharan, Sidhu P.; Gioux, Sylvain

2013-12-01

We report the design, characterization, and validation of an optimized simultaneous color and near-infrared (NIR) fluorescence rigid endoscopic imaging system for minimally invasive surgery. This system is optimized for illumination and collection of NIR wavelengths allowing the simultaneous acquisition of both color and NIR fluorescence at frame rates higher than 6.8 fps with high sensitivity. The system employs a custom 10-mm diameter rigid endoscope optimized for NIR transmission. A dual-channel light source compatible with the constraints of an endoscope was built and includes a plasma source for white light illumination and NIR laser diodes for fluorescence excitation. A prism-based 2-CCD camera was customized for simultaneous color and NIR detection with a highly efficient filtration scheme for fluorescence imaging of both 700- and 800-nm emission dyes. The performance characterization studies indicate that the endoscope can efficiently detect fluorescence signal from both indocyanine green and methylene blue in dimethyl sulfoxide at the concentrations of 100 to 185 nM depending on the background optical properties. Finally, we performed the validation of this imaging system in vivo during a minimally invasive procedure for thoracic sentinel lymph node mapping in a porcine model.

Reconstruction, Enhancement, Visualization, and Ergonomic Assessment for Laparoscopic Surgery

DTIC Science & Technology

2007-02-01

support and upgrade of the REVEAL display system and tool suite in the University of Maryland Medical Center’s Simulation Center, (2) stereo video display...technology deployment, (3) stereo probe calibration benchmarks and support tools , (4) the production of research media, (5) baseline results from...endoscope can be used to generate a stereoscopic view for a surgeon, as with the DaVinci robot in use today. In order to use such an endoscope for

Feasibility of Obtaining Quantitative 3-Dimensional Information Using Conventional Endoscope: A Pilot Study

PubMed Central

Hyun, Jong Jin; Keum, Bora; Seo, Yeon Seok; Kim, Yong Sik; Jeen, Yoon Tae; Lee, Hong Sik; Um, Soon Ho; Kim, Chang Duck; Ryu, Ho Sang; Lim, Jong-Wook; Woo, Dong-Gi; Kim, Young-Joong; Lim, Myo-Taeg

2012-01-01

Background/Aims Three-dimensional (3D) imaging is gaining popularity and has been partly adopted in laparoscopic surgery or robotic surgery but has not been applied to gastrointestinal endoscopy. As a first step, we conducted an experiment to evaluate whether images obtained by conventional gastrointestinal endoscopy could be used to acquire quantitative 3D information. Methods Two endoscopes (GIF-H260) were used in a Borrmann type I tumor model made of clay. The endoscopes were calibrated by correcting the barrel distortion and perspective distortion. Obtained images were converted to gray-level image, and the characteristics of the images were obtained by edge detection. Finally, data on 3D parameters were measured by using epipolar geometry, two view geometry, and pinhole camera model. Results The focal length (f) of endoscope at 30 mm was 258.49 pixels. Two endoscopes were fixed at predetermined distance, 12 mm (d12). After matching and calculating disparity (v2-v1), which was 106 pixels, the calculated length between the camera and object (L) was 29.26 mm. The height of the object projected onto the image (h) was then applied to the pinhole camera model, and the result of H (height and width) was 38.21 mm and 41.72 mm, respectively. Measurements were conducted from 2 different locations. The measurement errors ranged from 2.98% to 7.00% with the current Borrmann type I tumor model. Conclusions It was feasible to obtain parameters necessary for 3D analysis and to apply the data to epipolar geometry with conventional gastrointestinal endoscope to calculate the size of an object. PMID:22977798

Correction of motion artifacts in endoscopic optical coherence tomography and autofluorescence images based on azimuthal en face image registration.

PubMed

Abouei, Elham; Lee, Anthony M D; Pahlevaninezhad, Hamid; Hohert, Geoffrey; Cua, Michelle; Lane, Pierre; Lam, Stephen; MacAulay, Calum

2018-01-01

We present a method for the correction of motion artifacts present in two- and three-dimensional in vivo endoscopic images produced by rotary-pullback catheters. This method can correct for cardiac/breathing-based motion artifacts and catheter-based motion artifacts such as nonuniform rotational distortion (NURD). This method assumes that en face tissue imaging contains slowly varying structures that are roughly parallel to the pullback axis. The method reduces motion artifacts using a dynamic time warping solution through a cost matrix that measures similarities between adjacent frames in en face images. We optimize and demonstrate the suitability of this method using a real and simulated NURD phantom and in vivo endoscopic pulmonary optical coherence tomography and autofluorescence images. Qualitative and quantitative evaluations of the method show an enhancement of the image quality. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Novel computer-based endoscopic camera

NASA Astrophysics Data System (ADS)

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.

Targeted detection of murine colonic dysplasia in vivo with flexible multispectral scanning fiber endoscopy

NASA Astrophysics Data System (ADS)

Miller, Sharon J.; Lee, Cameron M.; Joshi, Bishnu P.; Gaustad, Adam; Seibel, Eric J.; Wang, Thomas D.

2012-02-01

Gastrointestinal cancers are heterogeneous and can overexpress several protein targets that can be imaged simultaneously on endoscopy using multiple molecular probes. We aim to demonstrate a multispectral scanning fiber endoscope for wide-field fluorescence detection of colonic dysplasia. Excitation at 440, 532, and 635 nm is delivered into a single spiral scanning fiber, and fluorescence is collected by a ring of light-collecting optical fibers placed around the instrument periphery. Specific-binding peptides are selected with phage display technology using the CPC;Apc mouse model of spontaneous colonic dysplasia. Validation of peptide specificity is performed on flow cytometry and in vivo endoscopy. The peptides KCCFPAQ, AKPGYLS, and LTTHYKL are selected and labeled with 7-diethylaminocoumarin-3-carboxylic acid (DEAC), 5-carboxytetramethylrhodamine (TAMRA), and CF633, respectively. Separate droplets of KCCFPAQ-DEAC, AKPGYLS-TAMRA, and LTTHYKL-CF633 are distinguished at concentrations of 100 and 1 μM. Separate application of the fluorescent-labeled peptides demonstrate specific binding to colonic adenomas. The average target/background ratios are 1.71+/-0.19 and 1.67+/-0.12 for KCCFPAQ-DEAC and AKPGYLS-TAMRA, respectively. Administration of these two peptides together results in distinct binding patterns in the blue and green channels. Specific binding of two or more peptides can be distinguished in vivo using a novel multispectral endoscope to localize colonic dysplasia on real-time wide-field imaging.

Radiological and endoscopic imaging methods in the management of cystic pancreatic neoplasms.

PubMed

Aslan, Ahmet; Inan, Ibrahim; Orman, Süleyman; Aslan, Mine; Acar, Murat

2017-01-01

The management of cystic pancreatic neoplasm (CPN) is a clinical dilemma because of its clinical presentations and malignant potential. Surgery is the best treatment choice ; however, pancreatic surgery still has high complication rates, even in experienced centers. Imaging methods have a definitive role in the management of CPN and computed tomography, magnetic resonance imaging, and endoscopic ultrasonography are the preferred methods since they can reveal the suspicious features for malignancy. Therefore, radiologists, gastroenterologists, endoscopists, and surgeons should be aware of the common features of CPN, its discrete presentations on imaging methods, and the limitations of these modalities in the management of the disease. This study aims to review the radiological and endoscopic imaging methods used for the management of CPN. © Acta Gastro-Enterologica Belgica.

Possibilities of lasers within NOTES.

PubMed

Stepp, Herbert; Sroka, Ronald

2010-10-01

Lasers possess unique properties that render them versatile light sources particularly for NOTES. Depending on the laser light sources used, diagnostic as well as therapeutic purposes can be achieved. The diagnostic potential offered by innovative concepts such as new types of ultra-thin endoscopes and optical probes supports the physician with optical information of ultra-high resolution, tissue discrimination and manifold types of fluorescence detection. In addition, the potential 3-D capability promises enhanced recognition of tissue type and pathological status. These diagnostic techniques might enable or at least contribute to accurate and safe procedures within the spatial restrictions inherent with NOTES. The therapeutic potential ranges from induction of phototoxic effects over tissue welding, coagulation and tissue cutting to stone fragmentation. As proven in many therapeutic laser endoscopic treatment concepts, laser surgery is potentially bloodless and transmits the energy without mechanical forces. Specialized NOTES endoscopes will likely incorporate suitable probes for improving diagnostic procedures, laser fibres with advantageous light delivery possibility or innovative laser beam manipulation systems. NOTES training centres may support the propagation of the complex handling and the safety aspects for clinical use to the benefit of the patient.

Fiber-Laser-Based Ultrasound Sensor for Photoacoustic Imaging

PubMed Central

Liang, Yizhi; Jin, Long; Wang, Lidai; Bai, Xue; Cheng, Linghao; Guan, Bai-Ou

2017-01-01

Photoacoustic imaging, especially for intravascular and endoscopic applications, requires ultrasound probes with miniature size and high sensitivity. In this paper, we present a new photoacoustic sensor based on a small-sized fiber laser. Incident ultrasound waves exert pressures on the optical fiber laser and induce harmonic vibrations of the fiber, which is detected by the frequency shift of the beating signal between the two orthogonal polarization modes in the fiber laser. This ultrasound sensor presents a noise-equivalent pressure of 40 Pa over a 50-MHz bandwidth. We demonstrate this new ultrasound sensor on an optical-resolution photoacoustic microscope. The axial and lateral resolutions are 48 μm and 3.3 μm. The field of view is up to 1.57 mm2. The sensor exhibits strong resistance to environmental perturbations, such as temperature changes, due to common-mode cancellation between the two orthogonal modes. The present fiber laser ultrasound sensor offers a new tool for all-optical photoacoustic imaging. PMID:28098201

Design and modeling of a prototype fiber scanning CARS endoscope

NASA Astrophysics Data System (ADS)

Veilleux, Isra"l.; Doucet, Michel; Coté, Patrice; Verreault, Sonia; Fortin, Michel; Paradis, Patrick; Leclair, Sébastien; Da Costa, Ralph S.; Wilson, Brian C.; Seibel, Eric; Mermut, Ozzy; Cormier, Jean-François

2010-02-01

An endoscope capable of Coherent Anti-Stokes Raman scattering (CARS) imaging would be of significant clinical value for improving early detection of endoluminal cancers. However, developing this technology is challenging for many reasons. First, nonlinear imaging techniques such as CARS are single point measurements thus requiring fast scanning in a small footprint if video rate is to be achieved. Moreover, the intrinsic nonlinearity of this modality imposes several technical constraints and limitations, mainly related to pulse and beam distortions that occur within the optical fiber and the focusing objective. Here, we describe the design and report modeling results of a new CARS endoscope. The miniature microscope objective design and its anticipated performance are presented, along with its compatibility with a new spiral scanningfiber imaging technology developed at the University of Washington. This technology has ideal attributes for clinical use, with its small footprint, adjustable field-of-view and high spatial-resolution. This compact hybrid fiber-based endoscopic CARS imaging design is anticipated to have a wide clinical applicability.

Navigation technique for MR-endoscope system using a wireless accelerometer-based remote control device.

PubMed

Kumamoto, Etsuko; Takahashi, Akihiro; Matsuoka, Yuichiro; Morita, Yoshinori; Kutsumi, Hiromu; Azuma, Takeshi; Kuroda, Kagayaki

2013-01-01

The MR-endoscope system can perform magnetic resonance (MR) imaging during endoscopy and show the images obtained by using endoscope and MR. The MR-endoscope system can acquire a high-spatial resolution MR image with an intraluminal radiofrequency (RF) coil, and the navigation system shows the scope's location and orientation inside the human body and indicates MR images with a scope view. In order to conveniently perform an endoscopy and MR procedure, the design of the user interface is very important because it provides useful information. In this study, we propose a navigation system using a wireless accelerometer-based controller with Bluetooth technology and a navigation technique to set the intraluminal RF coil using the navigation system. The feasibility of using this wireless controller in the MR shield room was validated via phantom examinations of the influence on MR procedures and navigation accuracy. In vitro examinations using an isolated porcine stomach demonstrated the effectiveness of the navigation technique using a wireless remote-control device.

Hollow fiber-optic Raman probes for small experimental animals

NASA Astrophysics Data System (ADS)

Katagiri, Takashi; Hattori, Yusuke; Suzuki, Toshiaki; Matsuura, Yuji; Sato, Hidetoshi

2007-02-01

Two types of hollow fiber-optic probes are developed to measure the in vivo Raman spectra of small animals. One is the minimized probe which is end-sealed with the micro-ball lens. The measured spectra reflect the information of the sample's sub-surface. This probe is used for the measurement of the esophagus and the stomach via an endoscope. The other probe is a confocal Raman probe which consists of a single fiber and a lens system. It is integrated into the handheld microscope. A simple and small multimodal probe is realized because the hollow optical fiber requires no optical filters. The performance of each probe is examined and the effectiveness of these probes for in vivo Raman spectroscopy is shown by animal tests.

An enhanced narrow-band imaging method for the microvessel detection

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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.

Correction of rotational distortion for catheter-based en face OCT and OCT angiography

PubMed Central

Ahsen, Osman O.; Lee, Hsiang-Chieh; Giacomelli, Michael G.; Wang, Zhao; Liang, Kaicheng; Tsai, Tsung-Han; Potsaid, Benjamin; Mashimo, Hiroshi; Fujimoto, James G.

2015-01-01

We demonstrate a computationally efficient method for correcting the nonuniform rotational distortion (NURD) in catheter-based imaging systems to improve endoscopic en face optical coherence tomography (OCT) and OCT angiography. The method performs nonrigid registration using fiducial markers on the catheter to correct rotational speed variations. Algorithm performance is investigated with an ultrahigh-speed endoscopic OCT system and micromotor catheter. Scan nonuniformity is quantitatively characterized, and artifacts from rotational speed variations are significantly reduced. Furthermore, we present endoscopic en face OCT and OCT angiography images of human gastrointestinal tract in vivo to demonstrate the image quality improvement using the correction algorithm. PMID:25361133

Optic for an endoscope/borescope having high resolution and narrow field of view

DOEpatents

Stone, Gary F.; Trebes, James E.

2003-10-28

An optic having optimized high spatial resolution, minimal nonlinear magnification distortion while at the same time having a limited chromatic focal shift or chromatic aberrations. The optic located at the distal end of an endoscopic inspection tool permits a high resolution, narrow field of view image for medical diagnostic applications, compared to conventional optics for endoscopic instruments which provide a wide field of view, low resolution image. The image coverage is over a narrow (<20 degrees) field of view with very low optical distortion (<5% pin cushion or barrel distortion. The optic is also optimized for best color correction as well as to aid medical diagnostics.

Nanowire-based single-cell endoscopy

NASA Astrophysics Data System (ADS)

Yan, Ruoxue; Park, Ji-Ho; Choi, Yeonho; Heo, Chul-Joon; Yang, Seung-Man; Lee, Luke P.; Yang, Peidong

2012-03-01

One-dimensional smart probes based on nanowires and nanotubes that can safely penetrate the plasma membrane and enter biological cells are potentially useful in high-resolution and high-throughput gene and drug delivery, biosensing and single-cell electrophysiology. However, using such probes for optical communication across the cellular membrane at the subwavelength level remains limited. Here, we show that a nanowire waveguide attached to the tapered tip of an optical fibre can guide visible light into intracellular compartments of a living mammalian cell, and can also detect optical signals from subcellular regions with high spatial resolution. Furthermore, we show that through light-activated mechanisms the endoscope can deliver payloads into cells with spatial and temporal specificity. Moreover, insertion of the endoscope into cells and illumination of the guided laser did not induce any significant toxicity in the cells.

The effect of light intensity on image quality in endoscopic ear surgery.

PubMed

McCallum, R; McColl, J; Iyer, A

2018-05-16

Endoscopic ear surgery is a rapidly developing field with many advantages. But endoscopes can reach temperatures of over 110°C at the tip, raising safety concerns. Reducing the intensity of the light source reduces temperatures produced. However, quality of images at lower light intensities has not yet been studied. We set out to study the effect of light intensity on image quality in EES. Prospective study of patients undergoing EES from April to October 2016. Consecutive images of the same operative field at 10%, 30%, 50% and 100% light intensities were taken. Eight international experts were asked to each evaluate 100 anonymised, randomised images. District General Hospital. Twenty patients. Images were evaluated on a 5-point Likert scale (1 = significantly worse than average; 5 = significantly better than average) for detail of anatomy; colour contrast; overall quality; and suitability for operating. Mean scores for photographs at 10%, 30%, 50% and 100% light intensity were 3.22 (SD 0.93), 3.15 (SD 0.84), 3.08 (SD 0.88) and 3.10 (SD 0.86), respectively. In ANOVA models for the scores on each of the scales (anatomy, colour contrast, overall quality and suitability for operating), the effects of rater and patient were highly significant (P < .0005) but light intensity was non-significant (P = .34, .32, .21, .15, respectively). Images taken during surgery by our endoscope and operative camera have no loss of quality when taken at lower light intensities. We recommend the surgeon considers use of lower light intensities in endoscopic ear surgery. © 2018 John Wiley & Sons Ltd.

Implementation of real-time digital endoscopic image processing system

NASA Astrophysics Data System (ADS)

Song, Chul Gyu; Lee, Young Mook; Lee, Sang Min; Kim, Won Ky; Lee, Jae Ho; Lee, Myoung Ho

1997-10-01

Endoscopy has become a crucial diagnostic and therapeutic procedure in clinical areas. Over the past four years, we have developed a computerized system to record and store clinical data pertaining to endoscopic surgery of laparascopic cholecystectomy, pelviscopic endometriosis, and surgical arthroscopy. In this study, we developed a computer system, which is composed of a frame grabber, a sound board, a VCR control board, a LAN card and EDMS. Also, computer system controls peripheral instruments such as a color video printer, a video cassette recorder, and endoscopic input/output signals. Digital endoscopic data management system is based on open architecture and a set of widely available industry standards; namely Microsoft Windows as an operating system, TCP/IP as a network protocol and a time sequential database that handles both images and speech. For the purpose of data storage, we used MOD and CD- R. Digital endoscopic system was designed to be able to store, recreate, change, and compress signals and medical images. Computerized endoscopy enables us to generate and manipulate the original visual document, making it accessible to a virtually unlimited number of physicians.

Comparison of adrenaline injection and bipolar electrocoagulation for the arrest of peptic ulcer bleeding

PubMed Central

Lin, H; Tseng, G; Perng, C; Lee, F; Chang, F; Lee, S

1999-01-01

BACKGROUND—Peptic ulcers with active bleeding or a non-bleeding visible vessel require aggressive endoscopic treatment. 
AIMS—To determine whether endoscopic adrenaline injection alone or contact probe therapy following injection is a suitable treatment for peptic ulcer bleeding. 
METHODS—A total of 96 patients with active bleeding or non-bleeding visible vessels received adrenaline alone, bipolar electrocoagulation alone, or combined treatment (n=32 in each group). 
RESULTS—Initial haemostasis was not achieved in one patient in the adrenaline group, two in the gold probe group, and two in the injection gold probe group (p>0.1). Rebleeding episodes were fewer in the injection gold probe group (2/30, 6.7%) than in the gold probe group (9/30, 30%, p=0.04) and in the adrenaline group (11/31, 35.5%, p=0.01). Treatment failure (other therapy required) was rarer in the injection gold probe group (4/32, 12.5%) than in the adrenaline group (12/32, 37.5%, p=0.04). The volume of blood transfused after entry of the study was less in the injection gold probe group (mean 491 ml) than in the adrenaline group (1548ml, p<0.0001) and the gold probe group (1105 ml, p<0.01). Duration of hospital stay, numbers of patients requiring urgent surgery, and death rate were not statistically different among the three groups. 
CONCLUSIONS—For patients with peptic ulcer bleeding, combined adrenaline injection and gold probe treatment offers an advantage in preventing rebleeding and decreasing the need for blood transfusion. 

 Keywords: gold probe; haemostasis; injectional therapy; rebleeding; shock; peptic ulcer PMID:10205211

Oblique incidence reflectometry: optical models and measurements using a side-viewing gradient index lens-based endoscopic imaging system

NASA Astrophysics Data System (ADS)

Wall, R. Andrew; Barton, Jennifer K.

2014-06-01

A side-viewing, 2.3-mm diameter oblique incidence reflectometry endoscope has been designed to obtain optical property measurements of turbid samples. Light from a single-mode fiber is relayed obliquely onto the tissue with a gradient index lens-based distal optics assembly and the resulting diffuse reflectance profile is imaged and collected with a 30,000 element, 0.72 mm clear aperture fiber bundle. Sampling the diffuse reflectance in two-dimensions allows for fitting of the reflected intensity profile to a well-known theoretical model, permitting the extraction of both absorption and reduced scattering coefficients of the tissue sample. Models and measurements of the endoscopic imaging system are presented in tissue phantoms and in vivo mouse colon, verifying the endoscope's capabilities to accurately measure effective attenuation coefficient and differentiate diseased from normal colon.

Scanning fiber endoscopy with highly flexible, 1-mm catheterscopes for wide-field, full-color imaging

PubMed Central

Lee, Cameron M.; Engelbrecht, Christoph J.; Soper, Timothy D.; Helmchen, Fritjof; Seibel, Eric J.

2011-01-01

In modern endoscopy, wide field of view and full color are considered necessary for navigating inside the body, inspecting tissue for disease and guiding interventions such as biopsy or surgery. Current flexible endoscope technologies suffer from reduced resolution when device diameter shrinks. Endoscopic procedures today using coherent fiber bundle technology, on the scale of 1 mm, are performed with such poor image quality that the clinician’s vision meets the criteria for legal blindness. Here, we review a new and versatile scanning fiber imaging technology and describe its implementation for ultrathin and flexible endoscopy. This scanning fiber endoscope (SFE) or catheterscope enables high quality, laser-based, video imaging for ultrathin clinical applications while also providing new options for in vivo biological research of subsurface tissue and high resolution fluorescence imaging. PMID:20336702

Early outcomes of endoscopic transsphenoidal surgery for adult craniopharyngiomas.

PubMed

Jane, John A; Kiehna, Erin; Payne, Spencer C; Early, Stephen V; Laws, Edward R

2010-04-01

Although the transsphenoidal approach for subdiaphragmatic craniopharyngiomas has been performed for many years, there are few reports describing the role of the endoscopic transsphenoidal technique for suprasellar craniopharyngiomas. The purpose of this study was to report the outcomes of the endoscopic transsphenoidal approach for adults with craniopharyngiomas in whom the goal was gross-total resection. Twelve patients were identified who were older than 18 years at the time of their pure endoscopic transsphenoidal surgery. Their medical records and imaging studies were retrospectively reviewed. Gross-total resection was achieved in 42% of cases when assessed by intraoperative impression alone and in 75% when assessed by the first postoperative MR imaging study. However, 83% of patients achieved at least a 95% resection when assessed by both intraoperative impression and the first postoperative MR imaging study. Permanent diabetes insipidus occurred postoperatively in 44% of patients. Six (67%) of 9 patients who had a functioning hypothalamic-pituitary axis preoperatively developed panhypopituitarism after surgery. Visual improvement or normalization occurred in 78% of patients with preoperative visual deficits. Although no patient experienced a postoperative CSF leak, 1 patient was treated for meningitis. The authors have achieved a high rate of radical resection and symptomatic improvement with the endoscopic transsphenoidal technique for both subdiaphragmatic (sellar/suprasellar) and supradiaphragmatic (suprasellar) craniopharyngiomas. However, this is also associated with a high incidence of new endocrinopathy. Endoscopic assessment of tumor resection may be more sensitive for residual tumor than the first postoperative MR imaging study.

Design and implementation of fiber-based multiphoton endoscopy with microelectromechanical systems scanning

PubMed Central

Tang, Shuo; Jung, Woonggyu; McCormick, Daniel; Xie, Tuqiang; Su, Jiangping; Ahn, Yeh-Chan; Tromberg, Bruce J.; Chen, Zhongping

2010-01-01

A multiphoton endoscopy system has been developed using a two-axis microelectromechanical systems (MEMS) mirror and double-cladding photonic crystal fiber (DCPCF). The MEMS mirror has a 2-mm-diam, 20-deg optical scanning angle, and 1.26-kHz and 780-Hz resonance frequencies on the x and y axes. The maximum number of resolvable focal spots of the MEMS scanner is 720×720 on the x and y axes, which indicates that the MEMS scanner can potentially support high-resolution multiphoton imaging. The DCPCF is compared with standard single-mode fiber and hollow-core photonic bandgap fiber on the basis of dispersion, attenuation, and coupling efficiency properties. The DCPCF has high collection efficiency, and its dispersion can be compensated by grating pairs. Three configurations of probe design are investigated, and their imaging quality and field of view are compared. A two-lens configuration with a collimation and a focusing lens provides the optimum imaging performance and packaging flexibility. The endoscope is applied to image fluorescent microspheres and bovine knee joint cartilage. PMID:19566298

Broadband rotary joint for high speed ultrahigh resolution endoscopic OCT imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Alemohammad, Milad; Yuan, Wu; Mavadia-Shukla, Jessica; Liang, Wenxuan; Yu, Xiaoyun; Yu, Shaoyong; Li, Xingde

2016-03-01

Endoscopic OCT is a promising technology enabling noninvasive in vivo imaging of internal organs, such as the gastrointestinal tract and airways. The past few years have witnessed continued efforts to achieve ultrahigh resolution and speed. It is well-known that the axial resolution in OCT imaging has a quadratic dependence on the central wavelength. While conventional OCT endoscopes operate in 1300 nm wavelength, the second-generation endoscopes are designed for operation around 800 nm where turn-key, broadband sources are becoming readily available. Traditionally 1300 nm OCT endoscopes are scanned at the proximal end, and a broadband fiber-optic rotary joint as a key component in scanning endoscopic OCT is commercially available. Bandwidths in commercial 800 nm rotary joints are unfortunately compromised due to severe chromatic aberration, which limits the resolution afforded by the broadband light source. In the past we remedied this limitation by using a home-made capillary-tube-based rotary joint where the maximum reliable speed is ~10 revolutions/second. In this submission we report our second-generation, home-built high-speed and broadband rotary joint for 800 nm wavelength, which uses achromatic doublets in order achieve broadband achromatic operation. The measured one-way throughput of the rotary joint is >67 % while the fluctuation of the double-pass coupling efficiency during 360° rotation is less than +/-5 % at a speed of 70 revolutions/second. We demonstrate the operation of this rotary joint in conjunction with our ultrahigh-resolution (2.4 µm in air) diffractive catheter by three-dimensional full-circumferential endoscopic imaging of guinea pig esophagus at 70 frames per second in vivo.

A pilot trial of ambulatory monitoring of gastric motility using a modified magnetic capsule endoscope.

PubMed

Kim, Hee Man; Choi, Ja Sung; Cho, Jae Hee

2014-04-30

The magnetic capsule endoscope has been modified to be fixed inside the stomach and to monitor the gastric motility. This pilot trial was designed to investigate the feasibility of the magnetic capsule endoscope for monitoring gastric motility. The magnetic capsule endoscope was swallowed by the healthy volunteer and maneuvered by the external magnet on his abdomen surface inside the stomach. The magnetic capsule endoscope transmitted image of gastric peristalsis. This simple trial suggested that the real-time ambulatory monitoring of gastric motility should be feasible by using the magnetic capsule endoscope.

Compact probing system using remote imaging for industrial plant maintenance

NASA Astrophysics Data System (ADS)

Ito, F.; Nishimura, A.

2014-03-01

Laser induced breakdown spectroscopy (LIBS) and endoscope observation were combined to design a remote probing device. We use this probing device to inspect a crack of the inner wall of the heat exchanger. Crack inspection requires speed at first, and then it requires accuracy. Once Eddy Current Testing (ECT) finds a crack with a certain signal level, another method should confirm it visually. We are proposing Magnetic particle Testing (MT) using specially fabricated the Magnetic Particle Micro Capsule (MPMC). For LIBS, a multichannel spectrometer and a Q-switch YAG laser were used. Irradiation area is 270 μm, and the pulse energy was 2 mJ. This pulse energy corresponds to 5-2.2 MW/cm2. A composite-type optical fiber was used to deliver both laser energy and optical image. Samples were prepared to heat a zirconium alloy plate by underwater arc welding in order to demonstrate severe accidents of nuclear power plants. A black oxide layer covered the weld surface and white particles floated on water surface. Laser induced breakdown plasma emission was taken into the spectroscope using this optical fiber combined with telescopic optics. As a result, we were able to simultaneously perform spectroscopic measurement and observation. For MT, the MPMC which gathered in the defective area is observed with this fiber. The MPMC emits light by the illumination of UV light from this optical fiber. The size of a defect is estimated with this amount of emission. Such technology will be useful for inspection repair of reactor pipe.

LC-lens array with light field algorithm for 3D biomedical applications

NASA Astrophysics Data System (ADS)

Huang, Yi-Pai; Hsieh, Po-Yuan; Hassanfiroozi, Amir; Martinez, Manuel; Javidi, Bahram; Chu, Chao-Yu; Hsuan, Yun; Chu, Wen-Chun

2016-03-01

In this paper, liquid crystal lens (LC-lens) array was utilized in 3D bio-medical applications including 3D endoscope and light field microscope. Comparing with conventional plastic lens array, which was usually placed in 3D endoscope or light field microscope system to record image disparity, our LC-lens array has higher flexibility of electrically changing its focal length. By using LC-lens array, the working distance and image quality of 3D endoscope and microscope could be enhanced. Furthermore, the 2D/3D switching ability could be achieved if we turn off/on the electrical power on LClens array. In 3D endoscope case, a hexagonal micro LC-lens array with 350um diameter was placed at the front end of a 1mm diameter endoscope. With applying electric field on LC-lens array, the 3D specimen would be recorded as from seven micro-cameras with different disparity. We could calculate 3D construction of specimen with those micro images. In the other hand, if we turn off the electric field on LC-lens array, the conventional high resolution 2D endoscope image would be recorded. In light field microscope case, the LC-lens array was placed in front of the CMOS sensor. The main purpose of LC-lens array is to extend the refocusing distance of light field microscope, which is usually very narrow in focused light field microscope system, by montaging many light field images sequentially focusing on different depth. With adjusting focal length of LC-lens array from 2.4mm to 2.9mm, the refocusing distance was extended from 1mm to 11.3mm. Moreover, we could use a LC wedge to electrically shift the optics axis and increase the resolution of light field.

Techniques of imaging of the aorta and its first order branches by endoscopic ultrasound (with videos)

PubMed Central

Sharma, Malay; Rai, Praveer; Mehta, Varun; Rameshbabu, C. S.

2015-01-01

Endoscopic ultrasonography (EUS) is a useful modality for imaging of the blood vessels of the mediastinum and abdomen. The aorta acts as an important home base during EUS imaging. The aorta and its branches are accessible by standard angiographic methods, but endosonography also provides a unique opportunity to evaluate the aorta and its branches. This article describes the techniques of imaging of different part of the aorta by EUS. PMID:26020043

New endoscopic and cytologic tools for cancer surveillance in the digestive tract

PubMed Central

Brentnall, Teresa A.; Dominitz, Jason A.

2009-01-01

Synopsis Cancer surveillance is an increasing part of everyday practice in gastrointestinal endoscopy due to the identification of high risk groups from genetic and biomarker testing, genealogic and epidemiologic studies, and the increasing number of cancer survivors. An efficient surveillance program requires a cost-effective means for image-guided cancer detection and biopsy. A laser-based tethered-capsule endoscope with enhanced spectral imaging is introduced for unsedated surveillance of the lower esophagus. An ultrathin version of this same endoscope technology provides a 1.2-mm guidewire with imaging capability and cannula-style tools are proposed for image-guided biopsy. Advanced 3D cell visualization techniques are described for increasing the sensitivity of early cancer diagnosis from hematoxylin-stained cells sampled from the pancreatic and biliary ducts. PMID:19423026

Endoscopic ultrasound: state-of-the-art GI tumor staging

NASA Astrophysics Data System (ADS)

Trowers, Eugene A.

1999-06-01

Videoendoscopy has truly enlarged the scope of diagnostic and therapeutic gastroenterology. However, videoendoscopic examinations are limited to the mucosal surface. Endoscopic ultrasound allows the endoscopist a view beyond the intestinal wall which opens the door to a variety of new gastroenterologic techniques. The evaluation of plain images in combination with contrast-enhanced imags has been found to be helpful when applied to CT and MRI. A similar advantage may be found for endoscopic ultrasound (EUS) studies. The efficacy of EUS with and without contrast enhancement is critically reviewed.

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

PubMed

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.

A CMOS One-chip Wireless Camera with Digital Image Transmission Function for Capsule Endoscopes

NASA Astrophysics Data System (ADS)

Itoh, Shinya; Kawahito, Shoji; Terakawa, Susumu

This paper presents the design and implementation of a one-chip camera device for capsule endoscopes. This experimental chip integrates functional circuits required for capsule endoscopes and digital image transmission function. The integrated functional blocks include an image array, a timing generator, a clock generator, a voltage regulator, a 10b cyclic A/D converter, and a BPSK modulator. It can be operated autonomously with 3 pins (VDD, GND, and DATAOUT). A prototype image sensor chip which has 320x240 effective pixels was fabricated using 0.25μm CMOS image sensor process and the autonomous imaging was demonstrated. The chip size is 4.84mmx4.34mm. With a 2.0 V power supply, the analog part consumes 950μW and the total power consumption at 2 frames per second (fps) is 2.6mW. Error-free image transmission over a distance of 48cm at 2.5Mbps corresponding to 2fps has been succeeded with inductive coupling.

In vivo imaging in the oral cavity by endoscopic optical coherence tomography.

PubMed

Walther, Julia; Schnabel, Christian; Tetschke, Florian; Rosenauer, Tobias; Golde, Jonas; Ebert, Nadja; Baumann, Michael; Hannig, Christian; Koch, Edmund

2018-03-01

The common way to diagnose hard and soft tissue irregularities in the oral cavity is initially the visual inspection by an experienced dentist followed by further medical examinations, such as radiological imaging and/or histopathological investigation. For the diagnosis of oral hard and soft tissues, the detection of early transformations is mostly hampered by poor visual access, low specificity of the diagnosis techniques, and/or limited feasibility of frequent screenings. Therefore, optical noninvasive diagnosis of oral tissue is promising to improve the accuracy of oral screening. Considering this demand, a rigid handheld endoscopic scanner was developed for optical coherence tomography (OCT). The novelty is the usage of a commercially near-infrared endoscope with fitting optics in combination with an established spectral-domain OCT system of our workgroup. By reaching a high spatial resolution, in vivo images of anterior and especially posterior dental and mucosal tissues were obtained from the oral cavity of two volunteers. The convincing image quality of the endoscopic OCT device is particularly obvious for the imaging of different regions of the human soft palate with highly scattering fibrous layer and capillary network within the lamina propria. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Catheter-based photoacoustic endoscope

PubMed Central

Yang, Joon-Mo; Li, Chiye; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

2014-01-01

Abstract. We report a flexible shaft-based mechanical scanning photoacoustic endoscopy (PAE) system that can be potentially used for imaging the human gastrointestinal tract via the instrument channel of a clinical video endoscope. The development of such a catheter endoscope has been an important challenge to realize the technique’s benefits in clinical settings. We successfully implemented a prototype PAE system that has a 3.2-mm diameter and 2.5-m long catheter section. As the instrument’s flexible shaft and scanning tip are fully encapsulated in a plastic catheter, it easily fits within the 3.7-mm diameter instrument channel of a clinical video endoscope. Here, we demonstrate the intra-instrument channel workability and in vivo animal imaging capability of the PAE system. PMID:24887743

Characterization of photoacoustic sources in tissue using time domain measurements

NASA Astrophysics Data System (ADS)

Viator, John Andrew

Photoacoustic phenomenon in tissue and tissue phantoms is investigated with the particular goal of discrimination of diseased and healthy tissue. Propagation of broadband photoacoustic sources in tissue phantoms is studied with emphasis on attenuation, dispersion, and diffraction. Attenuation of photoacoustic waves induced by a circular laser spot on an absorber/air interface is modeled by the on-axis approximation of the acoustic field of a baffled piston source. Dispersion is studied in a diffraction free situation, where the disk of irradiation was created by a 5 mm laser spot on a 200 cm -1 solution. The genesis of diffraction in an absorbing solution was displayed by showing the merging of a boundary wave with a plane wave from a circular laser spot on an absorbing solution. Depth profiling of absorbing tissue phantoms and stained tissue was shown using a photoacoustic method. Acrylamide gels with layers of different optical absorption and stained elastin biomaterials were irradiated with stress confined laser pulses. The resulting acoustic waves were detected with a lithium niobate wideband acoustic transducer and processed in an algorithm to determine absorption coefficient as a function of depth. Spherical photoacoustic sources were generated in optically clear and turbid tissue phantoms. Propagation time and acoustic pulse duration were used to determine location and size, respectively. The photoacoustic sources were imaged using a multiplicative backprojection scheme. Image sources from acoustic boundaries were detected and dipole sources were detected and imaged. Finally an endoscopic photoacoustic probe was designed, built, and tested for use in determining treatment depth after palliative photodynamic therapy of esophageal cancer. The probe was less than 2.5 mm in diameter and consisted of a side firing 600 mum optical fiber to deliver laser energy and a 890 mum diameter, side viewing piezoelectric detector. The sensitivity of the probe was determined. The probe was also tested on coagulated and non-coagulated liver, ex vivo and on normally perfused and underperfused human skin, in vivo.

Flexible micro-OCT endobronchial probe for imaging of mucociliary transport (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cui, Dongyao; Chu, Kengyeh K.; Unglert, Carolin I.; Ford, Tim N.; Carruth, Robert W.; Hyun, Daryl; Singh, Kanwarpal; Birket, Susan E.; Solomon, George M.; Rowe, Steve M.; Tearney, Guillermo J.

2016-03-01

Mucociliary clearance (MCC) plays a significant role in maintaining the health of human respiratory system by eliminating foreign particles trapped within mucus. Failure of this mechanism in diseases such as cystic fibrosis and chronic obstructive pulmonary disease (COPD) leads to airway blockage and lung infection, causing morbidity and mortality. The volume of airway mucus and the periciliary liquid encapsulating the cilia, in addition to ciliary beat frequency and velocity of mucociliary transport, are vital parameters of airway health. However, the diagnosis of disease pathogenesis and advances of novel therapeutics are hindered by the lack of tools for visualization of ciliary function in vivo. Our laboratory has previously developed a 1-µm resolution optical coherence tomography method, termed Micro-OCT, which is capable of visualizing mucociliary transport and quantitatively capturing epithelial functional metrics. We have also miniaturized Micro-OCT optics in a first-generation rigid 4mm Micro-OCT endoscope utilizing a common-path design and an apodizing prism configuration to produce an annular profile sample beam, and reported the first in vivo visualization of mucociliary transport in swine. We now demonstrate a flexible 2.5 mm Micro-OCT probe that can be inserted through the instrument channel of standard flexible bronchoscopes, allowing bronchoscopic navigation to smaller airways and greatly improving clinical utility. Longitudinal scanning over a field of view of more than 400 µm at a frame rate of 40 Hz was accomplished with a driveshaft transduced by a piezo-electric stack motor. We present characterization and imaging results from the flexible micro-OCT probe and progress towards clinical translation. The ability of the bronchoscope-compatible micro-OCT probe to image mucus clearance and epithelial function will enable studies of cystic fibrosis pathogenesis in small airways, provide diagnosis of mucociliary clearance disorders, and allow individual responses to treatments to be monitored.

Ultrahigh-resolution optical coherence elastography through a micro-endoscope: towards in vivo imaging of cellular-scale mechanics

PubMed Central

Fang, Qi; Curatolo, Andrea; Wijesinghe, Philip; Yeow, Yen Ling; Hamzah, Juliana; Noble, Peter B.; Karnowski, Karol; Sampson, David D.; Ganss, Ruth; Kim, Jun Ki; Lee, Woei M.; Kennedy, Brendan F.

2017-01-01

In this paper, we describe a technique capable of visualizing mechanical properties at the cellular scale deep in living tissue, by incorporating a gradient-index (GRIN)-lens micro-endoscope into an ultrahigh-resolution optical coherence elastography system. The optical system, after the endoscope, has a lateral resolution of 1.6 µm and an axial resolution of 2.2 µm. Bessel beam illumination and Gaussian mode detection are used to provide an extended depth-of-field of 80 µm, which is a 4-fold improvement over a fully Gaussian beam case with the same lateral resolution. Using this system, we demonstrate quantitative elasticity imaging of a soft silicone phantom containing a stiff inclusion and a freshly excised malignant murine pancreatic tumor. We also demonstrate qualitative strain imaging below the tissue surface on in situ murine muscle. The approach we introduce here can provide high-quality extended-focus images through a micro-endoscope with potential to measure cellular-scale mechanics deep in tissue. We believe this tool is promising for studying biological processes and disease progression in vivo. PMID:29188108

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

PubMed

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.

Improving the image discontinuous problem by using color temperature mapping method

NASA Astrophysics Data System (ADS)

Jeng, Wei-De; Mang, Ou-Yang; Lai, Chien-Cheng; Wu, Hsien-Ming

2011-09-01

This article mainly focuses on image processing of radial imaging capsule endoscope (RICE). First, it used the radial imaging capsule endoscope (RICE) to take the images, the experimental used a piggy to get the intestines and captured the images, but the images captured by RICE were blurred due to the RICE has aberration problems in the image center and lower light uniformity affect the image quality. To solve the problems, image processing can use to improve it. Therefore, the images captured by different time can use Person correlation coefficient algorithm to connect all the images, and using the color temperature mapping way to improve the discontinuous problem in the connection region.

Micro-optical fiber probe for use in an intravascular Raman endoscope.

PubMed

Komachi, Yuichi; Sato, Hidetoshi; Aizawa, Katsuo; Tashiro, Hideo

2005-08-01

We believe that we have developed the narrowest optical-fiber Raman probe ever reported, 600 microm in total diameter, that can be inserted into coronary arteries. The selection of suitable optical fibers, filters, and a processing method is discussed. Custom-made filters attached to the front end of a probe eliminate the background Raman signals of the optical fiber itself. The experimental evaluation of various optical fibers is carried out for the selection of suitable fibers. Measurement of the Raman spectra of an atherosclerotic lesion of a rabbit artery in vitro demonstrates the excellent performance of the micro-Raman probe.

Endoscopic high-resolution auto fluorescence imaging and optical coherence tomography of airways in vivo (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pahlevaninezhad, Hamid; Lee, Anthony; Hohert, Geoffrey; Schwartz, Carley; Shaipanich, Tawimas; Ritchie, Alexander J.; Zhang, Wei; MacAulay, Calum E.; Lam, Stephen; Lane, Pierre M.

2016-03-01

In this work, we present multimodal imaging of peripheral airways in vivo using an endoscopic imaging system capable of co-registered optical coherence tomography and autofluorescence imaging (OCT-AFI). This system employs a 0.9 mm diameter double-clad fiber optic-based catheter for endoscopic imaging of small peripheral airways. Optical coherence tomography (OCT) can visualize detailed airway morphology in the lung periphery and autofluorescence imaging (AFI) can visualize fluorescent tissue components such as collagen and elastin, improving the detection of airway lesions. Results from in vivo imaging of 40 patients indicate that OCT and AFI offer complementary information that may increase the ability to identify pulmonary nodules in the lung periphery and improve the safety of biopsy collection by identifying large blood vessels. AFI can rapidly visualize in vivo vascular networks using fast scanning parameters resulting in vascular-sensitive imaging with less breathing/cardiac motion artifacts compared to Doppler OCT imaging. By providing complementary information about structure and function of tissue, OCT-AFI may improve site selection during biopsy collection in the lung periphery.

Treatments for achalasia in 2017: how to choose among them.

PubMed

Kahrilas, Peter J; Pandolfino, John E

2017-07-01

To review recent advances in achalasia diagnostics and therapeutics. The cardinal feature of achalasia, impaired lower esophageal sphincter (LES) relaxation, can occur in association with varied patterns of esophageal contractility. The Chicago Classification distinguishes among these as follows: without contractility (type I), with panesophageal pressurization (type II), with premature (spastic) distal esophageal contractions (type III), or even with preserved peristalsis [esophagogastric junction (EGJ) outlet obstruction]. Physiological testing also reveals achalasia-like syndromes that also benefit from achalasia therapies. Coincident with this has been the development of peroral endoscopic myotomy (POEM), an endoscopic technique for performing an esophageal myotomy. Hence, the option now exists to either selectively ablate the LES (pneumatic dilation, laparoscopic Heller myotomy, or POEM) or to ablate the sphincter and create a myotomy along some or the entire adjacent smooth muscle esophagus (POEM). Each achalasia syndrome has unique treatment considerations; type II achalasia responds well to all therapies, whereas type III responds best to POEM. Emerging data support the concept that optimal management of achalasia is phenotype-specific, guided by high-resolution manometry, and, in some instance, functional luminal imaging probe studies. This opinion article reviews the varied characteristic and treatment considerations of achalasia syndromes as currently understood.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ingram, S; Rao, A; Wendt, R

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 cameramore » 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.« less

Development of a cylindrical diffusing optical fiber probe for pancreatic cancer therapy

NASA Astrophysics Data System (ADS)

Lee, Sangyeob; Park, Gaye; Park, Jihoon; Yu, Sungkon; Ha, Myungjin; Jang, Seulki; Ouh, Chihwan; Jung, Changhyun; Jung, Byungjo

2017-02-01

Although the patients with cancer on pancreas or pancreaticobiliary duct have been increased, it is very difficult to detect and to treat the pancreatic cancer because of its low accessibility and obtuseness. The pancreatic cancer has been diagnosed using ultrasonography, blood test, CT, endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasonography (EUS) and etc. Normally, light can be delivered to the target by optical fibers through the ERCP or EUS. Diffusing optical fibers have been developed with various methods. However, many of them have mechanical and biological problems in the use of small-bend-radius apparatus or in tissue area. This study developed a therapeutic cylindrical diffusing optical fiber probe (CDOFP) for ERCP and EUS which has moderate flexibility and solidity to treat the cancer on pancreaticobiliary duct or pancreas. The CDOFP consists of a biocompatible Teflon tube and multimode glass fiber which has diffusing area processed with laser and high refractive index resin. The CDOFP was characterized to investigate the clinical feasibility and other applications of light therapy using diffusing optical fiber. The results presented that the CDOFP may be used in clinic by combining with endoscopic method, such as ERCP or EUS, to treat cancer on pancreas and pancreaticobiliary duct.

A video-based speed estimation technique for localizing the wireless capsule endoscope inside gastrointestinal tract.

PubMed

Bao, Guanqun; Mi, Liang; Geng, Yishuang; Zhou, Mingda; Pahlavan, Kaveh

2014-01-01

Wireless Capsule Endoscopy (WCE) is progressively emerging as one of the most popular non-invasive imaging tools for gastrointestinal (GI) tract inspection. As a critical component of capsule endoscopic examination, physicians need to know the precise position of the endoscopic capsule in order to identify the position of intestinal disease. For the WCE, the position of the capsule is defined as the linear distance it is away from certain fixed anatomical landmarks. In order to measure the distance the capsule has traveled, a precise knowledge of how fast the capsule moves is urgently needed. In this paper, we present a novel computer vision based speed estimation technique that is able to extract the speed of the endoscopic capsule by analyzing the displacements between consecutive frames. The proposed approach is validated using a virtual testbed as well as the real endoscopic images. Results show that the proposed method is able to precisely estimate the speed of the endoscopic capsule with 93% accuracy on average, which enhances the localization accuracy of the WCE to less than 2.49 cm.

Chip-on-the-tip compact flexible endoscopic epifluorescence video-microscope for in-vivo imaging in medicine and biomedical research

PubMed Central

Matz, Gregor; Messerschmidt, Bernhard; Göbel, Werner; Filser, Severin; Betz, Christian S.; Kirsch, Matthias; Uckermann, Ortrud; Kunze, Marcel; Flämig, Sven; Ehrhardt, André; Irion, Klaus-Martin; Haack, Mareike; Dorostkar, Mario M.; Herms, Jochen; Gross, Herbert

2017-01-01

We demonstrate a 60 mg light video-endomicroscope with a cylindrical shape of the rigid tip of only 1.6 mm diameter and 6.7 mm length. A novel implementation method of the illumination unit in the endomicroscope is presented. It allows for the illumination of the biological sample with fiber-coupled LED light at 455 nm and the imaging of the red-shifted fluorescence light above 500 nm in epi-direction. A large numerical aperture of 0.7 leads to a sub-cellular resolution and yields to high-contrast images within a field of view of 160 μm. A miniaturized chip-on-the-tip CMOS image sensor with more than 150,000 pixels captures the multicolor images at 30 fps. Considering size, plug-and-play capability, optical performance, flexibility and weight, we hence present a probe which sets a new benchmark in the field of epifluorescence endomicroscopes. Several ex-vivo and in-vivo experiments in rodents and humans suggest future application in biomedical fields, especially in the neuroscience community, as well as in medical applications targeting optical biopsies or the detection of cellular anomalies. PMID:28717570

Fully wireless pressure sensor based on endoscopy images

NASA Astrophysics Data System (ADS)

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.

In vivo white light and contrast-enhanced vital-dye fluorescence imaging of Barrett's-related neoplasia in a single-endoscopic insertion

NASA Astrophysics Data System (ADS)

Tang, Yubo; Carns, Jennifer; Polydorides, Alexandros D.; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca R.

2016-08-01

A modular video endoscope is developed to enable both white light imaging (WLI) and vital-dye fluorescence imaging (VFI) in a single-endoscopic insertion for the early detection of cancer in Barrett's esophagus (BE). We demonstrate that VFI can be achieved in conjunction with white light endoscopy, where appropriate white balance is used to correct for the presence of the emission filter. In VFI mode, a contrast enhancement feature is implemented in real time to further highlight glandular patterns in BE and related malignancies without introducing artifacts. In a pilot study, we demonstrate accurate correlation of images in two widefield modalities, with representative images showing the disruption and effacement of glandular architecture associated with cancer development in BE. VFI images of these alterations exhibit enhanced contrast when compared to WLI. Results suggest that the usefulness of VFI in the detection of BE-related neoplasia should be further evaluated in future in vivo studies.

Image Quality Analysis of Various Gastrointestinal Endoscopes: Why Image Quality Is a Prerequisite for Proper Diagnostic and Therapeutic Endoscopy

PubMed Central

Ko, Weon Jin; An, Pyeong; Ko, Kwang Hyun; Hahm, Ki Baik; Hong, Sung Pyo

2015-01-01

Arising from human curiosity in terms of the desire to look within the human body, endoscopy has undergone significant advances in modern medicine. Direct visualization of the gastrointestinal (GI) tract by traditional endoscopy was first introduced over 50 years ago, after which fairly rapid advancement from rigid esophagogastric scopes to flexible scopes and high definition videoscopes has occurred. In an effort towards early detection of precancerous lesions in the GI tract, several high-technology imaging scopes have been developed, including narrow band imaging, autofocus imaging, magnified endoscopy, and confocal microendoscopy. However, these modern developments have resulted in fundamental imaging technology being skewed towards red-green-blue and this technology has obscured the advantages of other endoscope techniques. In this review article, we have described the importance of image quality analysis using a survey to consider the diversity of endoscope system selection in order to better achieve diagnostic and therapeutic goals. The ultimate aims can be achieved through the adoption of modern endoscopy systems that obtain high image quality. PMID:26473119

Design and implementation of magnetically maneuverable capsule endoscope system with direction reference for image navigation.

PubMed

Sun, Zhen-Jun; Ye, Bo; Sun, Yi; Zhang, Hong-Hai; Liu, Sheng

2014-07-01

This article describes a novel magnetically maneuverable capsule endoscope system with direction reference for image navigation. This direction reference was employed by utilizing a specific magnet configuration between a pair of external permanent magnets and a magnetic shell coated on the external capsule endoscope surface. A pair of customized Cartesian robots, each with only 4 degrees of freedom, was built to hold the external permanent magnets as their end-effectors. These robots, together with their external permanent magnets, were placed on two opposite sides of a "patient bed." Because of the optimized configuration based on magnetic analysis between the external permanent magnets and the magnetic shell, a simplified control strategy was proposed, and only two parameters, yaw step angle and moving step, were necessary for the employed robotic system. Step-by-step experiments demonstrated that the proposed system is capable of magnetically maneuvering the capsule endoscope while providing direction reference for image navigation. © IMechE 2014.

MEMS-based liquid lens for capsule endoscope

NASA Astrophysics Data System (ADS)

Seo, S. W.; Han, S.; Seo, J. H.; Kim, Y. M.; Kang, M. S.; Min, N. G.; Choi, W. B.; Sung, M. Y.

2008-03-01

The capsule endoscope, a new application area of digital imaging, is growing rapidly but needs the versatile imaging capabilities such as auto-focusing and zoom-in to be an active diagnostic tool. The liquid lens based on MEMS technology can be a strong candidate because it is able to be small enough. In this paper, a cylinder-type liquid lens was designed based on Young-Lippmann model and then fabricated with MEMS technology combining the silicon thin-film process and the wafer bonding process. The focal length of the lens module including the fabricated liquid lens was changed reproducibly as a function of the applied voltage. With the change of 30V in the applied bias, the focal length of the constructed lens module could be tuned in the range of about 42cm. The fabricated liquid lens was also proven to be small enough to be adopted in the capsule endoscope, which means the liquid lens can be utilized for the imaging capability improvement of the capsule endoscope.

Real-time fusion of endoscopic views with dynamic 3-D cardiac images: a phantom study.

PubMed

Szpala, Stanislaw; Wierzbicki, Marcin; Guiraudon, Gerard; Peters, Terry M

2005-09-01

Minimally invasive robotically assisted cardiac surgical systems currently do not routinely employ 3-D image guidance. However, preoperative magnetic resonance and computed tomography (CT) images have the potential to be used in this role, if appropriately registered with the patient anatomy and animated synchronously with the motion of the actual heart. This paper discusses the fusion of optical images of a beating heart phantom obtained from an optically tracked endoscope, with volumetric images of the phantom created from a dynamic CT dataset. High quality preoperative dynamic CT images are created by first extracting the motion parameters of the heart from the series of temporal frames, and then applying this information to animate a high-quality heart image acquired at end systole. Temporal synchronization of the endoscopic and CT model is achieved by selecting the appropriate CT image from the dynamic set, based on an electrocardiographic trigger signal. The spatial error between the optical and virtual images is 1.4 +/- 1.1 mm, while the time discrepancy is typically 50-100 ms. Index Terms-Image guidance, image warping, minimally invasive cardiac surgery, virtual endoscopy, virtual reality.

Studies On Endoscopic Local Hyperthermia Using Nd-YAG Laser

NASA Astrophysics Data System (ADS)

Tsunekawa, H.; Kanemaki, N.; Furusawa, A.; Hotta, M.; Kuroiwa, A.; Nishida, M.; Mori, N.; Watanabe, Y.; Morise, K.; Iizuka, A.

1987-03-01

Attempting a new method of laser irradiation for depressed gastric carcinoma, using a newly developed interstitial probe and laser attenuator, we applied local hyperthermia with prolonged low watt contact irradiation. Experimental studies were performed with this probe, using BDF1 mice injected hypodermically with Lewis lung carcinoma. A laser power of 2.0 w at the tip of fiber produced the most desirable temperature curve, about 43 - 60°C at the irradiation site. Clinical applications were carried out on 15 patients with early gastric carcinoma (mainly depressed), 10 preoperative pilot cases and 5 inoperable cases. In follow-up operations and biopsies gastric carcinoma was found to have completely dis-appeared in 2 of the preoperative and 4 of the inoperable cases. In the remaining 8 preoperative cases residual traces of carcinoma were found at the margin of the laser ulcer, but not at the bottom of it. We propose that endoscopic local hyperthermia using interstitial probe and low power irradiation (2.0 W) is the safest and most suitable method of dealing with depressed carcinoma.

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

NASA Astrophysics Data System (ADS)

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.

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

PubMed

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.

Implemented a wireless communication system for VGA capsule endoscope.

PubMed

Moon, Yeon-Kwan; Lee, Jyung Hyun; Park, Hee-Joon; Cho, Jin-Ho; Choi, Hyun-Chul

2014-01-01

Recently, several medical devices that use wireless communication are under development. In this paper, the small size frequency shift keying (FSK) transmitter and a monofilar antenna for the capsule endoscope, enabling the medical device to transmit VGA-size images of the intestine. To verify the functionality of the proposed wireless communication system, computer simulations and animal experiments were performed with the implemented capsule endoscope that includes the proposed wireless communication system. Several fundamental experiments are carried out using the implemented transmitter and antenna, and animal in-vivo experiments were performed to verify VGA image transmission.

First Evaluation of the New Thin Convex Probe Endobronchial Ultrasound Scope: A Human Ex Vivo Lung Study.

PubMed

Patel, Priya; Wada, Hironobu; Hu, Hsin-Pei; Hirohashi, Kentaro; Kato, Tatsuya; Ujiie, Hideki; Ahn, Jin Young; Lee, Daiyoon; Geddie, William; Yasufuku, Kazuhiro

2017-04-01

Endobronchial ultrasonography (EBUS)-guided transbronchial needle aspiration allows for sampling of mediastinal lymph nodes. The external diameter, rigidity, and angulation of the convex probe EBUS renders limited accessibility. This study compares the accessibility and transbronchial needle aspiration capability of the prototype thin convex probe EBUS against the convex probe EBUS in human ex vivo lungs rejected for transplant. The prototype thin convex probe EBUS (BF-Y0055; Olympus, Tokyo, Japan) with a thinner tip (5.9 mm), greater upward angle (170 degrees), and decreased forward oblique direction of view (20 degrees) was compared with the current convex probe EBUS (6.9-mm tip, 120 degrees, and 35 degrees, respectively). Accessibility and transbronchial needle aspiration capability was assessed in ex vivo human lungs declined for lung transplant. The distance of maximum reach and sustainable endoscopic limit were measured. Transbronchial needle aspiration capability was assessed using the prototype 25G aspiration needle in segmental lymph nodes. In all evaluated lungs (n = 5), the thin convex probe EBUS demonstrated greater reach and a higher success rate, averaging 22.1 mm greater maximum reach and 10.3 mm further endoscopic visibility range than convex probe EBUS, and could assess selectively almost all segmental bronchi (98% right, 91% left), demonstrating nearly twice the accessibility as the convex probe EBUS (48% right, 47% left). The prototype successfully enabled cytologic assessment of subsegmental lymph nodes with adequate quality using the dedicated 25G aspiration needle. Thin convex probe EBUS has greater accessibility to peripheral airways in human lungs and is capable of sampling segmental lymph nodes using the aspiration needle. That will allow for more precise assessment of N1 nodes and, possibly, intrapulmonary lesions normally inaccessible to the conventional convex probe EBUS. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

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

PubMed

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ingram, W; Rao, A; Wendt, R

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 asmore » 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 framework that is clinically valuable and requires no specialized equipment.« less

Quantitative evaluation of in vivo vital-dye fluorescence endoscopic imaging for the detection of Barrett’s-associated neoplasia

PubMed Central

Thekkek, Nadhi; Lee, Michelle H.; Polydorides, Alexandros D.; Rosen, Daniel G.; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca

2015-01-01

Abstract. Current imaging tools are associated with inconsistent sensitivity and specificity for detection of Barrett’s-associated neoplasia. Optical imaging has shown promise in improving the classification of neoplasia in vivo. The goal of this pilot study was to evaluate whether in vivo vital dye fluorescence imaging (VFI) has the potential to improve the accuracy of early-detection of Barrett’s-associated neoplasia. In vivo endoscopic VFI images were collected from 65 sites in 14 patients with confirmed Barrett’s esophagus (BE), dysplasia, or esophageal adenocarcinoma using a modular video endoscope and a high-resolution microendoscope (HRME). Qualitative image features were compared to histology; VFI and HRME images show changes in glandular structure associated with neoplastic progression. Quantitative image features in VFI images were identified for objective image classification of metaplasia and neoplasia, and a diagnostic algorithm was developed using leave-one-out cross validation. Three image features extracted from VFI images were used to classify tissue as neoplastic or not with a sensitivity of 87.8% and a specificity of 77.6% (AUC=0.878). A multimodal approach incorporating VFI and HRME imaging can delineate epithelial changes present in Barrett’s-associated neoplasia. Quantitative analysis of VFI images may provide a means for objective interpretation of BE during surveillance. PMID:25950645

Quantitative evaluation of in vivo vital-dye fluorescence endoscopic imaging for the detection of Barrett's-associated neoplasia.

PubMed

Thekkek, Nadhi; Lee, Michelle H; Polydorides, Alexandros D; Rosen, Daniel G; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca

2015-05-01

Current imaging tools are associated with inconsistent sensitivity and specificity for detection of Barrett's-associated neoplasia. Optical imaging has shown promise in improving the classification of neoplasia in vivo. The goal of this pilot study was to evaluate whether in vivo vital dye fluorescence imaging (VFI) has the potential to improve the accuracy of early-detection of Barrett's-associated neoplasia. In vivo endoscopic VFI images were collected from 65 sites in 14 patients with confirmed Barrett's esophagus (BE), dysplasia, oresophageal adenocarcinoma using a modular video endoscope and a high-resolution microendoscope(HRME). Qualitative image features were compared to histology; VFI and HRME images show changes in glandular structure associated with neoplastic progression. Quantitative image features in VFI images were identified for objective image classification of metaplasia and neoplasia, and a diagnostic algorithm was developed using leave-one-out cross validation. Three image features extracted from VFI images were used to classify tissue as neoplastic or not with a sensitivity of 87.8% and a specificity of 77.6% (AUC = 0.878). A multimodal approach incorporating VFI and HRME imaging can delineate epithelial changes present in Barrett's-associated neoplasia. Quantitative analysis of VFI images may provide a means for objective interpretation of BE during surveillance.

Importance of histological evaluation in endoscopic resection of early colorectal cancer

PubMed Central

Yoshida, Naohisa; Naito, Yuji; Yagi, Nobuaki; Yanagisawa, Akio

2012-01-01

The diagnostic criteria for colonic intraepithelial tumors vary from country to country. While intramucosal adenocarcinoma is recognized in Japan, in Western countries adenocarcinoma is diagnosed only if the tumor invades to the submucosa and accesses the muscularis mucosae. However, endoscopic therapy, including endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), is used worldwide to treat adenoma and early colorectal cancer. Precise histopathological evaluation is important for the curativeness of these therapies as inappropriate endoscopic therapy causes local recurrence of the tumor that may develop into fatal metastasis. Therefore, colorectal ESD and EMR are not indicated for cancers with massive submucosal invasion. However, diagnosis of cancer with massive submucosal invasion by endoscopy is limited, even when magnifying endoscopy for pit pattern and narrow band imaging and flexible spectral imaging color of enhancement are performed. Therefore, occasional cancers with massive submucosal invasion will be treated by ESD and EMR. Precise histopathological evaluation of these lesions should be performed in order to determine the necessity of additional therapy, including surgical resection. PMID:22532932

Image-Based Navigation for Functional Endoscopic Sinus Surgery Using Structure From Motion.

PubMed

Leonard, Simon; Reiter, Austin; Sinha, Ayushi; Ishii, Masaru; Taylor, Russel H; Hager, Gregory D

2016-01-01

Functional Endoscopic Sinus Surgery (FESS) is a challenging procedure for otolaryngologists and is the main surgical approach for treating chronic sinusitis, to remove nasal polyps and open up passageways. To reach the source of the problem and to ultimately remove it, the surgeons must often remove several layers of cartilage and tissues. Often, the cartilage occludes or is within a few millimeters of critical anatomical structures such as nerves, arteries and ducts. To make FESS safer, surgeons use navigation systems that register a patient to his/her CT scan and track the position of the tools inside the patient. Current navigation systems, however, suffer from tracking errors greater than 1 mm, which is large when compared to the scale of the sinus cavities, and errors of this magnitude prevent from accurately overlaying virtual structures on the endoscope images. In this paper, we present a method to facilitate this task by 1) registering endoscopic images to CT data and 2) overlaying areas of interests on endoscope images to improve the safety of the procedure. First, our system uses structure from motion (SfM) to generate a small cloud of 3D points from a short video sequence. Then, it uses iterative closest point (ICP) algorithm to register the points to a 3D mesh that represents a section of a patients sinuses. The scale of the point cloud is approximated by measuring the magnitude of the endoscope's motion during the sequence. We have recorded several video sequences from five patients and, given a reasonable initial registration estimate, our results demonstrate an average registration error of 1.21 mm when the endoscope is viewing erectile tissues and an average registration error of 0.91 mm when the endoscope is viewing non-erectile tissues. Our implementation SfM + ICP can execute in less than 7 seconds and can use as few as 15 frames (0.5 second of video). Future work will involve clinical validation of our results and strengthening the robustness to initial guesses and erectile tissues.

Image-based navigation for functional endoscopic sinus surgery using structure from motion

NASA Astrophysics Data System (ADS)

Leonard, Simon; Reiter, Austin; Sinha, Ayushi; Ishii, Masaru; Taylor, Russell H.; Hager, Gregory D.

2016-03-01

Functional Endoscopic Sinus Surgery (FESS) is a challenging procedure for otolaryngologists and is the main surgical approach for treating chronic sinusitis, to remove nasal polyps and open up passageways. To reach the source of the problem and to ultimately remove it, the surgeons must often remove several layers of cartilage and tissues. Often, the cartilage occludes or is within a few millimeters of critical anatomical structures such as nerves, arteries and ducts. To make FESS safer, surgeons use navigation systems that register a patient to his/her CT scan and track the position of the tools inside the patient. Current navigation systems, however, suffer from tracking errors greater than 1 mm, which is large when compared to the scale of the sinus cavities, and errors of this magnitude prevent from accurately overlaying virtual structures on the endoscope images. In this paper, we present a method to facilitate this task by 1) registering endoscopic images to CT data and 2) overlaying areas of interests on endoscope images to improve the safety of the procedure. First, our system uses structure from motion (SfM) to generate a small cloud of 3D points from a short video sequence. Then, it uses iterative closest point (ICP) algorithm to register the points to a 3D mesh that represents a section of a patients sinuses. The scale of the point cloud is approximated by measuring the magnitude of the endoscope's motion during the sequence. We have recorded several video sequences from five patients and, given a reasonable initial registration estimate, our results demonstrate an average registration error of 1.21 mm when the endoscope is viewing erectile tissues and an average registration error of 0.91 mm when the endoscope is viewing non-erectile tissues. Our implementation SfM + ICP can execute in less than 7 seconds and can use as few as 15 frames (0.5 second of video). Future work will involve clinical validation of our results and strengthening the robustness to initial guesses and erectile tissues.

White Paper AGA: Advanced Imaging in Barrett's Esophagus.

PubMed

Sharma, Prateek; Brill, Joel; Canto, Marcia; DeMarco, Daniel; Fennerty, Brian; Gupta, Neil; Laine, Loren; Lieberman, David; Lightdale, Charles; Montgomery, Elizabeth; Odze, Robert; Tokar, Jeffrey; Kochman, Michael

2015-12-01

Enhanced imaging technologies such as narrow band imaging, flexible spectral imaging color enhancement, i-Scan, confocal laser endomicroscopy, and optical coherence tomography are readily available for use by endoscopists in routine clinical practice. In November 2014, the American Gastroenterological Association's Center for GI Innovation and Technology conducted a 2-day workshop to discuss endoscopic image enhancement technologies, focusing on their role in 2 specific clinical conditions (colon polyps and Barrett's esophagus) and on issues relating to training and implementation of these technologies (white papers). Although the majority of the studies that use enhanced imaging technologies have been positive, these techniques ideally need to be validated in larger cohorts and in community centers. As it stands today, detailed endoscopic examination with high-definition white-light endoscopy and random 4-quadrant biopsy remains the standard of care. However, the workshop panelists agreed that in the hands of endoscopists who have met the preservation and incorporation of valuable endoscopic innovation thresholds (diagnostic accuracy) with enhanced imaging techniques (specific technologies), use of the technique in Barrett's esophagus patients is appropriate. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

Capturing and stitching images with a large viewing angle and low distortion properties for upper gastrointestinal endoscopy

NASA Astrophysics Data System (ADS)

Liu, Ya-Cheng; Chung, Chien-Kai; Lai, Jyun-Yi; Chang, Han-Chao; Hsu, Feng-Yi

2013-06-01

Upper gastrointestinal endoscopies are primarily performed to observe the pathologies of the esophagus, stomach, and duodenum. However, when an endoscope is pushed into the esophagus or stomach by the physician, the organs behave similar to a balloon being gradually inflated. Consequently, their shapes and depth-of-field of images change continually, preventing thorough examination of the inflammation or anabrosis position, which delays the curing period. In this study, a 2.9-mm image-capturing module and a convoluted mechanism was incorporated into the tube like a standard 10- mm upper gastrointestinal endoscope. The scale-invariant feature transform (SIFT) algorithm was adopted to implement disease feature extraction on a koala doll. Following feature extraction, the smoothly varying affine stitching (SVAS) method was employed to resolve stitching distortion problems. Subsequently, the real-time splice software developed in this study was embedded in an upper gastrointestinal endoscope to obtain a panoramic view of stomach inflammation in the captured images. The results showed that the 2.9-mm image-capturing module can provide approximately 50 verified images in one spin cycle, a viewing angle of 120° can be attained, and less than 10% distortion can be achieved in each image. Therefore, these methods can solve the problems encountered when using a standard 10-mm upper gastrointestinal endoscope with a single camera, such as image distortion, and partial inflammation displays. The results also showed that the SIFT algorithm provides the highest correct matching rate, and the SVAS method can be employed to resolve the parallax problems caused by stitching together images of different flat surfaces.

Real-time tracking and virtual endoscopy in cone-beam CT-guided surgery of the sinuses and skull base in a cadaver model.

PubMed

Prisman, Eitan; Daly, Michael J; Chan, Harley; Siewerdsen, Jeffrey H; Vescan, Allan; Irish, Jonathan C

2011-01-01

Custom software was developed to integrate intraoperative cone-beam computed tomography (CBCT) images with endoscopic video for surgical navigation and guidance. A cadaveric head was used to assess the accuracy and potential clinical utility of the following functionality: (1) real-time tracking of the endoscope in intraoperative 3-dimensional (3D) CBCT; (2) projecting an orthogonal reconstructed CBCT image, at or beyond the endoscope, which is parallel to the tip of the endoscope corresponding to the surgical plane; (3) virtual reality fusion of endoscopic video and 3D CBCT surface rendering; and (4) overlay of preoperatively defined contours of anatomical structures of interest. Anatomical landmarks were contoured in CBCT of a cadaveric head. An experienced endoscopic surgeon was oriented to the software and asked to rate the utility of the navigation software in carrying out predefined surgical tasks. Utility was evaluated using a rating scale for: (1) safely completing the task; and (2) potential for surgical training. Surgical tasks included: (1) uncinectomy; (2) ethmoidectomy; (3) sphenoidectomy/pituitary resection; and (4) clival resection. CBCT images were updated following each ablative task. As a teaching tool, the software was evaluated as "very useful" for all surgical tasks. Regarding safety and task completion, the software was evaluated as "no advantage" for task (1), "minimal" for task (2), and "very useful" for tasks (3) and (4). Landmark identification for structures behind bone was "very useful" for both categories. The software increased surgical confidence in safely completing challenging ablative tasks by presenting real-time image guidance for highly complex ablative procedures. In addition, such technology offers a valuable teaching aid to surgeons in training. Copyright © 2011 American Rhinologic Society-American Academy of Otolaryngic Allergy, LLC.

A Knowledge-Based System for the Computer Assisted Diagnosis of Endoscopic Images

NASA Astrophysics Data System (ADS)

Kage, Andreas; Münzenmayer, Christian; Wittenberg, Thomas

Due to the actual demographic development the use of Computer-Assisted Diagnosis (CAD) systems becomes a more important part of clinical workflows and clinical decision making. Because changes on the mucosa of the esophagus can indicate the first stage of cancerous developments, there is a large interest to detect and correctly diagnose any such lesion. We present a knowledge-based system which is able to support a physician with the interpretation and diagnosis of endoscopic images of the esophagus. Our system is designed to support the physician directly during the examination of the patient, thus prodving diagnostic assistence at the point of care (POC). Based on an interactively marked region in an endoscopic image of interest, the system provides a diagnostic suggestion, based on an annotated reference image database. Furthermore, using relevant feedback mechanisms, the results can be enhanced interactively.

Optical Design with Narrow-Band Imaging for a Capsule Endoscope.

PubMed

Yen, Chih-Ta; Lai, Zong-Wei; Lin, Yu-Ting; Cheng, Hsu-Chih

2018-01-01

The study proposes narrow-band imaging (NBI) lens design of 415 nm and 540 nm of a capsule endoscope (CE). The researches show that in terms of the rate of accuracy in detecting and screening neoplastic and nonneoplastic intestinal lesions, the NBI system outperformed that of traditional endoscopes and rivaled that of chromoendoscopes. In the proposed NBI CE optical system, the simulation result shows the field of view (FOV) was 109.8°; the modulation transfer function (MTF) could achieve 12.5% at 285 lp/mm and 34.1% at 144 lp/mm. The relative illumination reaches more than 60%, and the system total length was less than 4 mm. Finally, this design provides high-quality images for a 300-megapixel 1/4 ″ CMOS image sensor with a pixel size of 1.75  μ m.

Integration of single-fiber reflectance spectroscopy into ultrasound-guided endoscopic lung cancer staging of mediastinal lymph nodes

NASA Astrophysics Data System (ADS)

Kanick, Stephen Chad; van der Leest, Cor; Aerts, Joachim G. J. V.; Hoogsteden, Henk C.; Kaščáková, Slávka; Sterenborg, Henricus J. C. M.; Amelink, Arjen

2010-01-01

We describe the incorporation of a single-fiber reflectance spectroscopy probe into the endoscopic ultrasound fine-needle aspiration (EUS-FNA) procedure utilized for lung cancer staging. A mathematical model is developed to extract information about the physiological and morphological properties of lymph tissue from single-fiber reflectance spectra, e.g., microvascular saturation, blood volume fraction, bilirubin concentration, average vessel diameter, and Mie slope. Model analysis of data from a clinical pilot study shows that the single-fiber reflectance measurement is capable of detecting differences in the physiology between normal and metastatic lymph nodes. Moreover, the clinical data show that probe manipulation within the lymph node can perturb the in vivo environment, a concern that must be carefully considered when developing a sampling strategy. The data show the feasibility of this novel technique; however, the potential clinical utility has yet to be determined.

Fundamentals of bipolar high-frequency surgery.

PubMed

Reidenbach, H D

1993-04-01

In endoscopic surgery a very precise surgical dissection technique and an efficient hemostasis are of decisive importance. The bipolar technique may be regarded as a method which satisfies both requirements, especially regarding a high safety standard in application. In this context the biophysical and technical fundamentals of this method, which have been known in principle for a long time, are described with regard to the special demands of a newly developed field of modern surgery. After classification of this method into a general and a quasi-bipolar mode, various technological solutions of specific bipolar probes, in a strict and in a generalized sense, are characterized in terms of indication. Experimental results obtained with different bipolar instruments and probes are given. The application of modern microprocessor-controlled high-frequency surgery equipment and, wherever necessary, the integration of additional ancillary technology into the specialized bipolar instruments may result in most useful and efficient tools of a key technology in endoscopic surgery.

Image navigation as a means to expand the boundaries of fluorescence-guided surgery

NASA Astrophysics Data System (ADS)

Brouwer, Oscar R.; Buckle, Tessa; Bunschoten, Anton; Kuil, Joeri; Vahrmeijer, Alexander L.; Wendler, Thomas; Valdés-Olmos, Renato A.; van der Poel, Henk G.; van Leeuwen, Fijs W. B.

2012-05-01

Hybrid tracers that are both radioactive and fluorescent help extend the use of fluorescence-guided surgery to deeper structures. Such hybrid tracers facilitate preoperative surgical planning using (3D) scintigraphic images and enable synchronous intraoperative radio- and fluorescence guidance. Nevertheless, we previously found that improved orientation during laparoscopic surgery remains desirable. Here we illustrate how intraoperative navigation based on optical tracking of a fluorescence endoscope may help further improve the accuracy of hybrid surgical guidance. After feeding SPECT/CT images with an optical fiducial as a reference target to the navigation system, optical tracking could be used to position the tip of the fluorescence endoscope relative to the preoperative 3D imaging data. This hybrid navigation approach allowed us to accurately identify marker seeds in a phantom setup. The multispectral nature of the fluorescence endoscope enabled stepwise visualization of the two clinically approved fluorescent dyes, fluorescein and indocyanine green. In addition, the approach was used to navigate toward the prostate in a patient undergoing robot-assisted prostatectomy. Navigation of the tracked fluorescence endoscope toward the target identified on SPECT/CT resulted in real-time gradual visualization of the fluorescent signal in the prostate, thus providing an intraoperative confirmation of the navigation accuracy.

Quantitative evaluation of three advanced laparoscopic viewing technologies: a stereo endoscope, an image projection display, and a TFT display.

PubMed

Wentink, M; Jakimowicz, J J; Vos, L M; Meijer, D W; Wieringa, P A

2002-08-01

Compared to open surgery, minimally invasive surgery (MIS) relies heavily on advanced technology, such as endoscopic viewing systems and innovative instruments. The aim of the study was to objectively compare three technologically advanced laparoscopic viewing systems with the standard viewing system currently used in most Dutch hospitals. We evaluated the following advanced laparoscopic viewing systems: a Thin Film Transistor (TFT) display, a stereo endoscope, and an image projection display. The standard viewing system was comprised of a monocular endoscope and a high-resolution monitor. Task completion time served as the measure of performance. Eight surgeons with laparoscopic experience participated in the experiment. The average task time was significantly greater (p <0.05) with the stereo viewing system than with the standard viewing system. The average task times with the TFT display and the image projection display did not differ significantly from the standard viewing system. Although the stereo viewing system promises improved depth perception and the TFT and image projection displays are supposed to improve hand-eye coordination, none of these systems provided better task performance than the standard viewing system in this pelvi-trainer experiment.

Design and analysis of radial imaging capsule endoscope (RICE) system.

PubMed

Ou-Yang, Mang; Jeng, Wei-De

2011-02-28

In this study, a radial imaging capsule endoscope (RICE) system is designed, which differs from a conventional front imaging capsule endoscope (FICE) system. To observe the wrinkled intima of the intestine, which spreads without folding around the circumference of the capsule when a capsule endoscope with a diameter that slightly exceeds that of the intestine passes through it, the RICE uses a cone mirror, a radial window shell, and a focus optical module that comprise the radial imaging system. This concept was demonstrated in a packaged optical simulator. The RICE optical model also has been established and verified by many simulations and experiments. In minimizing the sagittal and tangential aberrations, the optical module of the RICE has achieved an F-number of 4.2, a viewing angle of 65.08°, and an RMS radius of the 4th to 6th fields of less than 17 um. A comparison of these characteristics with those of the focus optical module that is used in FICE lenses reveals that the spot size is 50% larger for each field, and the modulation transfer function (MTF) is remarkably improved from 7% to 36% at 100 lp/mm on the 5th field of the sagittal plane.

Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler.

PubMed

Beaudette, Kathy; Baac, Hyoung Won; Madore, Wendy-Julie; Villiger, Martin; Godbout, Nicolas; Bouma, Brett E; Boudoux, Caroline

2015-04-01

Double-clad fiber (DCF) is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and co-registered optical coherence tomography (OCT) and laser tissue coagulation. The DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light. We herein present a novel DCFC designed and built to combine both signals within a DCF (>90% of single-mode transmission; >65% multimode coupling). Potential OCT imaging degradation mechanisms are also investigated and solutions to mitigate them are presented. The combined DCFC-based system was used to induce coagulation of an ex vivo swine esophagus allowing a real-time assessment of thermal dynamic processes. We therefore demonstrate a DCFC-based system combining OCT imaging with laser coagulation through a single fiber, thus enabling both modalities to be performed simultaneously and in a co-registered manner. Such a system enables endoscopic image-guided laser marking of superficial epithelial tissues or laser thermal therapy of epithelial lesions in pathologies such as Barrett's esophagus.

Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler

PubMed Central

Beaudette, Kathy; Baac, Hyoung Won; Madore, Wendy-Julie; Villiger, Martin; Godbout, Nicolas; Bouma, Brett E.; Boudoux, Caroline

2015-01-01

Double-clad fiber (DCF) is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and co-registered optical coherence tomography (OCT) and laser tissue coagulation. The DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light. We herein present a novel DCFC designed and built to combine both signals within a DCF (>90% of single-mode transmission; >65% multimode coupling). Potential OCT imaging degradation mechanisms are also investigated and solutions to mitigate them are presented. The combined DCFC-based system was used to induce coagulation of an ex vivo swine esophagus allowing a real-time assessment of thermal dynamic processes. We therefore demonstrate a DCFC-based system combining OCT imaging with laser coagulation through a single fiber, thus enabling both modalities to be performed simultaneously and in a co-registered manner. Such a system enables endoscopic image-guided laser marking of superficial epithelial tissues or laser thermal therapy of epithelial lesions in pathologies such as Barrett’s esophagus. PMID:25909013

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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.

Monitoring blood-flow in the mouse cochlea using an endoscopic laser speckle contrast imaging system

PubMed Central

Yu, Sunkon; Jung, Byungjo; Choi, Jin Sil

2018-01-01

Laser speckle contrast imaging (LSCI) enables continuous high-resolution assessment of microcirculation in real-time. We applied an endoscope to LSCI to measure cochlear blood-flow in an ischemia–reperfusion mouse model. We also explored whether using xenon light in combination with LSCI facilitates visualization of anatomical position. Based on a previous preliminary study, the appropriate wavelength for penetrating the thin bony cochlea was 830 nm. A 2.7-mm-diameter endoscope was used, as appropriate for the size of the mouse cochlea. Our endoscopic LSCI system was used to illuminate the right cochlea after dissection of the mouse. We observed changes in the speckle signals when we applied the endoscopic LSCI system to the ischemia-reperfusion mouse model. The anatomical structure of the mouse cochlea and surrounding structures were clearly visible using the xenon light. The speckle signal of the cochlea was scattered, with an intensity that varied between that of the stapes (with the lowest signal), the negative control, and the stapedial artery (with the highest signal), the positive control. In the cochlear ischemia–reperfusion mouse model, the speckle signal of the cochlea decreased during the ischemic phase, and increased during the reperfusion phase, clearly reflecting cochlear blood-flow. The endoscopic LSCI system generates high-resolution images in real-time, allowing visualization of blood-flow and its changes in the mouse cochlea. Anatomical structures were clearly matched using LSCI along with visible light. PMID:29489849

Monitoring blood-flow in the mouse cochlea using an endoscopic laser speckle contrast imaging system.

PubMed

Kong, Tae Hoon; Yu, Sunkon; Jung, Byungjo; Choi, Jin Sil; Seo, Young Joon

2018-01-01

Laser speckle contrast imaging (LSCI) enables continuous high-resolution assessment of microcirculation in real-time. We applied an endoscope to LSCI to measure cochlear blood-flow in an ischemia-reperfusion mouse model. We also explored whether using xenon light in combination with LSCI facilitates visualization of anatomical position. Based on a previous preliminary study, the appropriate wavelength for penetrating the thin bony cochlea was 830 nm. A 2.7-mm-diameter endoscope was used, as appropriate for the size of the mouse cochlea. Our endoscopic LSCI system was used to illuminate the right cochlea after dissection of the mouse. We observed changes in the speckle signals when we applied the endoscopic LSCI system to the ischemia-reperfusion mouse model. The anatomical structure of the mouse cochlea and surrounding structures were clearly visible using the xenon light. The speckle signal of the cochlea was scattered, with an intensity that varied between that of the stapes (with the lowest signal), the negative control, and the stapedial artery (with the highest signal), the positive control. In the cochlear ischemia-reperfusion mouse model, the speckle signal of the cochlea decreased during the ischemic phase, and increased during the reperfusion phase, clearly reflecting cochlear blood-flow. The endoscopic LSCI system generates high-resolution images in real-time, allowing visualization of blood-flow and its changes in the mouse cochlea. Anatomical structures were clearly matched using LSCI along with visible light.

Image partitioning and illumination in image-based pose detection for teleoperated flexible endoscopes.

PubMed

Bell, Charreau S; Obstein, Keith L; Valdastri, Pietro

2013-11-01

Colorectal cancer is one of the leading causes of cancer-related deaths in the world, although it can be effectively treated if detected early. Teleoperated flexible endoscopes are an emerging technology to ease patient apprehension about the procedure, and subsequently increase compliance. Essential to teleoperation is robust feedback reflecting the change in pose (i.e., position and orientation) of the tip of the endoscope. The goal of this study is to first describe a novel image-based tracking system for teleoperated flexible endoscopes, and subsequently determine its viability in a clinical setting. The proposed approach leverages artificial neural networks (ANNs) to learn the mapping that links the optical flow between two sequential images to the change in the pose of the camera. Secondly, the study investigates for the first time how narrow band illumination (NBI) - today available in commercial gastrointestinal endoscopes - can be applied to enhance feature extraction, and quantify the effect of NBI and white light illumination (WLI), as well as their color information, on the strength of features extracted from the endoscopic camera stream. In order to provide the best features for the neural networks to learn the change in pose based on the image stream, we investigated two different imaging modalities - WLI and NBI - and we applied two different spatial partitions - lumen-centered and grid-based - to create descriptors used as input to the ANNs. An experiment was performed to compare the error of these four variations, measured in root mean square error (RMSE) from ground truth given by a robotic arm, to that of a commercial state-of-the-art magnetic tracker. The viability of this technique for a clinical setting was then tested using the four ANN variations, a magnetic tracker, and a commercial colonoscope. The trial was performed by an expert endoscopist (>2000 lifetime procedures) on a colonoscopy training model with porcine blood, and the RMSE of the ANN output was calculated with respect to the magnetic tracker readings. Using the image stream obtained from the commercial endoscope, the strength of features extracted was evaluated. In the first experiment, the best ANNs resulted from grid-based partitioning under WLI (2.42mm RMSE) for position, and from lumen-centered partitioning under NBI (1.69° RMSE) for rotation. By comparison, the performance of the tracker was 2.49mm RMSE in position and 0.89° RMSE in rotation. The trial with the commercial endoscope indicated that lumen-centered partitioning was the best overall, while NBI outperformed WLI in terms of illumination modality. The performance of lumen-centered partitioning with NBI was 1.03±0.8mm RMSE in positional degrees of freedom (DOF), and 1.26±0.98° RMSE in rotational DOF, while with WLI, the performance was 1.56±1.15mm RMSE in positional DOF and 2.45±1.90° RMSE in rotational DOF. Finally, the features extracted under NBI were found to be twice as strong as those extracted under WLI, but no significance in feature strengths was observed between a grayscale version of the image, and the red, blue, and green color channels. This work demonstrates that both WLI and NBI, combined with feature partitioning based on the anatomy of the colon, provide valid mechanisms for endoscopic camera pose estimation via image stream. Illumination provided by WLI and NBI produce ANNs with similar performance which are comparable to that of a state-of-the-art magnetic tracker. However, NBI produces features that are stronger than WLI, which enables more robust feature tracking, and better performance of the ANN in terms of accuracy. Thus, NBI with lumen-centered partitioning resulted the best approach among the different variations tested for vision-based pose estimation. The proposed approach takes advantage of components already available in commercial gastrointestinal endoscopes to provide accurate feedback about the motion of the tip of the endoscope. This solution may serve as an enabling technology for closed-loop control of teleoperated flexible endoscopes. Copyright © 2013 Elsevier B.V. All rights reserved.

A High-Resolution Endoscope of Small Diameter Using Electromagnetically Vibration of Single Fiber

NASA Astrophysics Data System (ADS)

Matsunaga, Tadao; Hino, Ryunosuke; Makishi, Wataru; Esashi, Masayoshi; Haga, Yoichi

For high resolution visual inspection in the narrow space of the human body, small diameter endoscope has been developed which utilize electromagnetically vibration of single fiber. Thin endoscopes are effective for inspection in the narrow space of the human body, for example, in the blood vessel, lactiferous duct for detection infiltration of breast cancer, and periodontal gap between gingiva and tooth. This endoscope consists of single optical fiber and photofabricated driving coils. A collimator lens and a cylindrical permanent magnet are fixed on the optical fiber, and the tilted driving coils have been patterned on a 1.08 mm outer diameter thin tube. The fiber is positioned at the center of the tube which is patterned the coils. When an electrical alternating current at the resonance frequency is supplied to the coils, the permanent magnet which is fixed to the fiber is vibrated electromagnetically and scanned one or two dimensionally. This paper reports small diameter endoscope by using electromagnetically vibration of single fiber. Optical coherence tomography imaging has also been carried out with the fabricated endoscope and cross-section image of sub-surface skin of thumb was observed.

Analysis of Preoperative Airway Examination with the CMOS Video Rhino-laryngoscope.

PubMed

Tsukamoto, Masanori; Hitosugi, Takashi; Yokoyama, Takeshi

2017-05-01

Endoscopy is one of the most useful clinical techniques in difficult airway management Comparing with the fibroptic endoscope, this compact device is easy to operate and can provide the clear image. In this study, we investigated its usefulness in the preoperative examination of endoscopy. Patients undergoing oral maxillofacial surgery were enrolled in this study. We performed preoperative airway examination by electronic endoscope (The CMOS video rhino-laryngoscope, KARL STORZ Endoscopy Japan, Tokyo). The system is composed of a videoendoscope, a compact video processor and a video recorder. In addition, the endoscope has a small color charge coupled device (CMOS) chip built into the tip of the endoscope. The outer diameter of the tip of this scope is 3.7 mm. In this study, electronic endoscope was used for preoperative airway examination in 7 patients. The preoperative airway examination with electronic endoscope was performed successfully in all the patients except one patient The patient had the symptoms such as nausea and vomiting at the examination. We could perform preoperative airway examination with excellent visualization and convenient recording of video sequence images with the CMOS video rhino-laryngoscope. It might be a especially useful device for the patients of difficult airways.

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

PubMed

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 < 0.001 for each). On review by expert radiologists, the sensitivity of MDCT increased to 83.3% in cases where the pancreatic duct was visualized, with fair IOA (κ = 0.34). Expert review of MRCPs did not identify any additional cases of 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.

Soft tissue navigation for laparoscopic prostatectomy: evaluation of camera pose estimation for enhanced visualization

NASA Astrophysics Data System (ADS)

Baumhauer, M.; Simpfendörfer, T.; Schwarz, R.; Seitel, M.; Müller-Stich, B. P.; Gutt, C. N.; Rassweiler, J.; Meinzer, H.-P.; Wolf, I.

2007-03-01

We introduce a novel navigation system to support minimally invasive prostate surgery. The system utilizes transrectal ultrasonography (TRUS) and needle-shaped navigation aids to visualize hidden structures via Augmented Reality. During the intervention, the navigation aids are segmented once from a 3D TRUS dataset and subsequently tracked by the endoscope camera. Camera Pose Estimation methods directly determine position and orientation of the camera in relation to the navigation aids. Accordingly, our system does not require any external tracking device for registration of endoscope camera and ultrasonography probe. In addition to a preoperative planning step in which the navigation targets are defined, the procedure consists of two main steps which are carried out during the intervention: First, the preoperatively prepared planning data is registered with an intraoperatively acquired 3D TRUS dataset and the segmented navigation aids. Second, the navigation aids are continuously tracked by the endoscope camera. The camera's pose can thereby be derived and relevant medical structures can be superimposed on the video image. This paper focuses on the latter step. We have implemented several promising real-time algorithms and incorporated them into the Open Source Toolkit MITK (www.mitk.org). Furthermore, we have evaluated them for minimally invasive surgery (MIS) navigation scenarios. For this purpose, a virtual evaluation environment has been developed, which allows for the simulation of navigation targets and navigation aids, including their measurement errors. Besides evaluating the accuracy of the computed pose, we have analyzed the impact of an inaccurate pose and the resulting displacement of navigation targets in Augmented Reality.

Application of optical coherence tomography and high-frequency ultrasound imaging during noninvasive laser vasectomy

NASA Astrophysics Data System (ADS)

Cilip, Christopher M.; Allaf, Mohamad E.; Fried, Nathaniel M.

2012-04-01

A noninvasive approach to vasectomy may eliminate male fear of complications related to surgery and increase its acceptance. Noninvasive laser thermal occlusion of the canine vas deferens has recently been reported. Optical coherence tomography (OCT) and high-frequency ultrasound (HFUS) are compared for monitoring laser thermal coagulation of the vas in an acute canine model. Bilateral noninvasive laser coagulation of the vas was performed in six dogs (n=12 vasa) using a Ytterbium fiber laser wavelength of 1075 nm, incident power of 9.0 W, pulse duration of 500 ms, pulse rate of 1 Hz, and 3-mm-diameter spot. Cryogen spray cooling was used to prevent skin burns during the procedure. An OCT system with endoscopic probe and a HFUS system with 20-MHz transducer were used to image the vas immediately before and after the procedure. Vasa were then excised and processed for gross and histologic analysis for comparison with OCT and HFUS images. OCT provided high-resolution, superficial imaging of the compressed vas within the vas ring clamp, while HFUS provided deeper imaging of the vas held manually in the scrotal fold. Both OCT and high HFUS are promising imaging modalities for real-time confirmation of vas occlusion during noninvasive laser vasectomy.

Comparison of organic electroluminescence and liquid crystal displays for clinical utility in orthopedic endoscopic surgery.

PubMed

Dezawa, Akira; Sairyo, Koichi

2014-05-01

Organic electroluminescence displays (OELD) use organic materials that self-emit light with the passage of an electric current. OELD provide high contrast, excellent color reproducibility at low brightness, excellent video images, and less restricted viewing angles. OELD are thus promising for medical use. This study compared the utility of an OELD with conventional liquid crystal displays (LCD) for imaging in orthopedic endoscopic surgery. One OELD and two conventional LCD that were indistinguishable in external appearance were used in this study. Images from 18 patients were displayed simultaneously on three monitors and evaluated by six orthopedic surgeons with extensive surgical experience. Images were shown for 2 min, repeated twice, and viewed from the front and side (diagonally). Surgeon rated both clinical utility (12 parameters) and image quality (11 parameters) for each image on a 5-point scale: 1, very good; 2, good; 3, average; 4, poor; and 5, very poor. For clinical utility in 16 percutaneous endoscopic discectomy cases, mean scores for all 12 parameters were significantly better on the OELD than on the LCD, including organ distinguishability (2.1 vs 3.2, respectively), lesion identification (2.2 vs 3.1), and overall viewing impression (2.1 vs 3.1). For image quality, all 11 parameters were better on the OELD than on LCD. Significant differences were identified in six parameters, including contrast (1.8 vs 2.9), color reproducibility in dark areas (1.8 vs 2.9), and viewing angle (2.2 vs 2.9). The high contrast and excellent color reproducibility of the OELD reduced the constraints of imaging under endoscopy, in which securing a field of view may be difficult. Distinguishability of organs was good, including ligaments, dura mater, nerves, and adipose tissue, contributing to good stereoscopic images of the surgical field. These findings suggest the utility of OELD for excellent display of surgical images and for enabling safe and highly accurate endoscopic surgery. © 2014 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.

The cranial nuchal bursa: anatomy, ultrasonography, magnetic resonance imaging and endoscopic approach.

PubMed

Abuja, G A; García-López, J M; Manso-Díaz, G; Spoormakers, T J P; Taeymans, O

2014-11-01

Although an uncommon condition, cranial nuchal bursitis can affect the performance of the equine athlete. The anatomy is not well described and there are no reports of diagnostic imaging for endoscopic approaches. To describe the anatomy, ultrasonographic and magnetic resonance features of and endoscopic approach to the cranial nuchal bursa in horses. Experimental cadaver study. Four cranial nuchal bursae were dissected, 4 specimens were frozen to prepare anatomical sections and 2 were injected with latex to document surface landmarks and topographical anatomy and to identify the possible sites for endoscopic access. Six cadaveric specimens were used to describe the ultrasonographic and magnetic resonance features of the cranial nuchal bursa before and after intrabursal injection. Sixteen cadaver specimens were evaluated with a rigid arthroscope and gross dissection to determine the endoscopic appearance of the bursa. The cranial nuchal bursa could be identified consistently in all cadavers, using ultrasonographic and magnetic resonance on both pre- and post injection specimens. Cranial and caudal endoscopic approaches and instrument portals were developed for the cranial nuchal bursa. Using either approach, the entire extent of the bursa could be evaluated, but separate approaches for left and right compartments of the bursa were needed owing to the lack of manoeuvrability when examining the contralateral compartment. The cranial nuchal bursa can be identified on ultrasonographic and magnetic resonance images. An endoscopic approach to the cranial nuchal bursa is clinically feasible and offered an easy, repeatable entry into the cranial nuchal bursa, which allowed adequate observation of the structures within the bursa. This may be of help for diagnosis and treatment of conditions affecting the cranial nuchal bursa in horses. © 2014 EVJ Ltd.

Computer-aided diagnosis of colorectal polyp histology by using a real-time image recognition system and narrow-band imaging magnifying colonoscopy.

PubMed

Kominami, Yoko; Yoshida, Shigeto; Tanaka, Shinji; Sanomura, Yoji; Hirakawa, Tsubasa; Raytchev, Bisser; Tamaki, Toru; Koide, Tetsusi; Kaneda, Kazufumi; Chayama, Kazuaki

2016-03-01

It is necessary to establish cost-effective examinations and treatments for diminutive colorectal tumors that consider the treatment risk and surveillance interval after treatment. The Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) committee of the American Society for Gastrointestinal Endoscopy published a statement recommending the establishment of endoscopic techniques that practice the resect and discard strategy. The aims of this study were to evaluate whether our newly developed real-time image recognition system can predict histologic diagnoses of colorectal lesions depicted on narrow-band imaging and to satisfy some problems with the PIVI recommendations. We enrolled 41 patients who had undergone endoscopic resection of 118 colorectal lesions (45 nonneoplastic lesions and 73 neoplastic lesions). We compared the results of real-time image recognition system analysis with that of narrow-band imaging diagnosis and evaluated the correlation between image analysis and the pathological results. Concordance between the endoscopic diagnosis and diagnosis by a real-time image recognition system with a support vector machine output value was 97.5% (115/118). Accuracy between the histologic findings of diminutive colorectal lesions (polyps) and diagnosis by a real-time image recognition system with a support vector machine output value was 93.2% (sensitivity, 93.0%; specificity, 93.3%; positive predictive value (PPV), 93.0%; and negative predictive value, 93.3%). Although further investigation is necessary to establish our computer-aided diagnosis system, this real-time image recognition system may satisfy the PIVI recommendations and be useful for predicting the histology of colorectal tumors. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Systems workplace for endoscopic surgery.

PubMed

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.

Endoscopic detection of murine colonic dysplasia using a novel fluorescence-labeled peptide

NASA Astrophysics Data System (ADS)

Miller, Sharon J.; Joshi, Bishnu P.; Gaustad, Adam; Fearon, Eric R.; Wang, Thomas D.

2011-03-01

Current endoscopic screening does not detect all pre-malignant (dysplastic) colorectal mucosa, thus requiring the development of more sensitive, targeted techniques to improve detection. The presented work utilizes phage display to identify a novel peptide binder to colorectal dysplasia in a CPC;Apc mouse model. A wide-field, small animal endoscope capable of fluorescence excitation (450-475 nm) identified polyps via white light and also collected fluorescence images (510 nm barrier filter) of peptide binding. The peptide bound ~2-fold greater to the colonic adenomas when compared to the control peptide. We have imaged fluorescence-labeled peptide binding in vivo that is specific towards distal colonic adenomas.

Results from the commissioning of a multi-modal endoscope for ultrasound and time of flight PET

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bugalho, Ricardo

2015-07-01

The EndoTOFPET-US collaboration has developed a multi-modal imaging system combining Ultrasound with Time-of-Flight Positron Emission Tomography into an endoscopic imaging device. The objective of the project is to obtain a coincidence time resolution of about 200 ps FWHM and to achieve about 1 mm spatial resolution of the PET system, while integrating all the components in a very compact detector suitable for endoscopic use. This scanner aims to be exploited for diagnostic and surgical oncology, as well as being instrumental in the clinical test of new biomarkers especially targeted for prostate and pancreatic cancer. (authors)

Imaging of endoscopic cystogastrostomy in pancreatic walled-off necrosis: what the radiologist needs to know.

PubMed

Abou Karam, Anthony; Bagherpour, Arya; Calleros, Jesus; Laks, Shaked

2018-04-04

Acute pancreatitis is a frequent entity encountered by radiologists. In 2012, the Atlanta criteria were revised to help radiologists use a common nomenclature when describing acute pancreatitis and its complications. One delayed complication of acute necrotizing pancreatitis in walled-off necrosis, a collection seen at least 4 weeks after an episode of acute pancreatic necrosis and/or acute peripancreatic necrosis. Multiple treatments have been adapted in the setting of walled-off necrosis, including endoscopic cystogastrostomy. The focus of this article is to familiarize the radiologist with the imaging appearance of this procedure as well as, review the outcomes and potential complications of endoscopic cystogastrostomy.

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

PubMed

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.

Endoscopic laser range scanner for minimally invasive, image guided kidney surgery

NASA Astrophysics Data System (ADS)

Friets, Eric; Bieszczad, Jerry; Kynor, David; Norris, James; Davis, Brynmor; Allen, Lindsay; Chambers, Robert; Wolf, Jacob; Glisson, Courtenay; Herrell, S. Duke; Galloway, Robert L.

2013-03-01

Image guided surgery (IGS) has led to significant advances in surgical procedures and outcomes. Endoscopic IGS is hindered, however, by the lack of suitable intraoperative scanning technology for registration with preoperative tomographic image data. This paper describes implementation of an endoscopic laser range scanner (eLRS) system for accurate, intraoperative mapping of the kidney surface, registration of the measured kidney surface with preoperative tomographic images, and interactive image-based surgical guidance for subsurface lesion targeting. The eLRS comprises a standard stereo endoscope coupled to a steerable laser, which scans a laser fan beam across the kidney surface, and a high-speed color camera, which records the laser-illuminated pixel locations on the kidney. Through calibrated triangulation, a dense set of 3-D surface coordinates are determined. At maximum resolution, the eLRS acquires over 300,000 surface points in less than 15 seconds. Lower resolution scans of 27,500 points are acquired in one second. Measurement accuracy of the eLRS, determined through scanning of reference planar and spherical phantoms, is estimated to be 0.38 +/- 0.27 mm at a range of 2 to 6 cm. Registration of the scanned kidney surface with preoperative image data is achieved using a modified iterative closest point algorithm. Surgical guidance is provided through graphical overlay of the boundaries of subsurface lesions, vasculature, ducts, and other renal structures labeled in the CT or MR images, onto the eLRS camera image. Depth to these subsurface targets is also displayed. Proof of clinical feasibility has been established in an explanted perfused porcine kidney experiment.

Novel multiplexed low coherence interferometry endoscopic probe for analyzing the cervical epithelium in vivo (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ho, Derek; Chu, Kengyeh K.; Crose, Michael; Desoto, Michael; Peters, Jennifer J.; Murtha, Amy P.; Wax, Adam

2017-02-01

The cervix is primarily composed of two types of epithelium: stratified squamous ectocervix and simple columnar endocervix. In between these two layers lies a metaplastic squamocolumnar junction commonly referred to as the transformation zone (T-zone). During puberty, the cervical epithelium undergoes dynamic changes including cervical ectropion and increased area and rates of metaplasia. Although these metaplastic changes have been linked to higher incidence of cervical cancer among young women, research in this field has been limited to surface analysis using computerized planimetry of colopophotographs. Here, we present a novel multiplexed low coherence interferometry (mLCI) system for interrogating the cervical epithelium. The system is comprised of 6 parallel Mach-Zehnder interferometers in a time-multiplexed configuration that increases throughput by 6-fold to realize a combined 36-channel acquisition. A custom designed endoscopic handheld probe is used to collect sparsely sampled, depth-resolved scattering intensity profiles (A-scans) from a large field of view (25 x 25 mm) on the cervical epithelium in vivo. The instrument incorporates white light imaging through a plastic fiber bundle to co-register the mLCI A-scans to colpophotographs which are analyzed by a clinician to manually segment the cervical epithelium. Our preliminary data shows significant differences in characteristic A-scans from endocervical and ectocervical epithelium. These results demonstrate the feasibility of using mLCI as both a research tool for studying the relationship between cervical ectopy and cancer as well as a clinical instrument for identifying the at-risk T-zone on the cervix in vivo as a means to improve biopsy targeting. Further analysis will be performed to develop an algorithm for distinguishing the mLCI A-scans of endocervical, ectocervical, and metaplastic epithelium in real time.

Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Huang, David

Optical coherence tomography (OCT) is a new method for noninvasive cross-sectional imaging in biological systems. In OCT, the longitudinal locations of tissue structures are determined by measuring the time-of-flight delays of light backscattered from these structures. The optical delays are measured by low coherence interferometry. Information on lateral position is provided by transverse scanning of the probe beam. The two dimensional map of optical scattering from internal tissue microstructures is then represented in a false-color or grayscale image. OCT is the optical analog of ultrasonic pulse-echo imaging, but with greatly improved spatial resolutions (a few microns). This thesis describes the development of this new high resolution tomographic imaging technology and the demonstration of its use in a variety of tissues under both in vitro and in vivo conditions. In vitro OCT ranging and imaging studies were performed using human ocular and arterial tissues, two clinically relevant examples of transparent and turbid media, respectively. In the anterior eye, precise measurements of cornea and anterior chamber dimensions were made. In the arterial specimens, the differentiation between fatty -calcified and fibromuscular tissues was demonstrated. In vivo OCT imaging in the retina and optic nerve head in human subjects was also performed. The delineation of retinal layers, which has not been possible with other noninvasive imaging techniques, is demonstrated in these OCT images. OCT has high spatial resolution but limited penetration into turbid tissue. It has potential for diagnostic applications where high resolution is needed and optical access is available, such as in the eye, skin, surgically exposed tissues, and surfaces that can be reached by various catheters and endoscopic probes. In particular, the measurement of fine retinal structures promises improvements in the diagnosis and management of glaucoma, macular edema and other vitreo-retinal diseases. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253 -1690.).

10-channel fiber array fabrication technique for parallel optical coherence tomography system

NASA Astrophysics Data System (ADS)

Arauz, Lina J.; Luo, Yuan; Castillo, Jose E.; Kostuk, Raymond K.; Barton, Jennifer

2007-02-01

Optical Coherence Tomography (OCT) shows great promise for low intrusive biomedical imaging applications. A parallel OCT system is a novel technique that replaces mechanical transverse scanning with electronic scanning. This will reduce the time required to acquire image data. In this system an array of small diameter fibers is required to obtain an image in the transverse direction. Each fiber in the array is configured in an interferometer and is used to image one pixel in the transverse direction. In this paper we describe a technique to package 15μm diameter fibers on a siliconsilica substrate to be used in a 2mm endoscopic probe tip. Single mode fibers are etched to reduce the cladding diameter from 125μm to 15μm. Etched fibers are placed into a 4mm by 150μm trench in a silicon-silica substrate and secured with UV glue. Active alignment was used to simplify the lay out of the fibers and minimize unwanted horizontal displacement of the fibers. A 10-channel fiber array was built, tested and later incorporated into a parallel optical coherence system. This paper describes the packaging, testing, and operation of the array in a parallel OCT system.

Endoscopic Skull Base Surgery

PubMed Central

Senior, Brent A

2008-01-01

Endoscopic skull base surgery has undergone rapid advancement in the past decade moving from pituitary surgery to suprasellar lesions and now to a myriad of lesions extending from the cribriform plate to C2 and laterally out to the infratemporal fossa and petrous apex. Evolution of several technological advances as well as advances in understanding of endoscopic anatomy and the development of surgical techniques both in resection and reconstruction have fostered this capability. Management of benign disease via endoscopic methods is largely accepted now but more data is needed before the controversy on the role of endoscopic management of malignant disease is decided. Continued advances in surgical technique, navigation systems, endoscopic imaging technology, and robotics assure continued brisk evolution in this expanding field. PMID:19434274

Cascade classification of endocytoscopic images of colorectal lesions for automated pathological diagnosis

NASA Astrophysics Data System (ADS)

Itoh, Hayato; Mori, Yuichi; Misawa, Masashi; Oda, Masahiro; Kudo, Shin-ei; Mori, Kensaku

2018-02-01

This paper presents a new classification method for endocytoscopic images. Endocytoscopy is a new endoscope that enables us to perform conventional endoscopic observation and ultramagnified observation of cell level. This ultramagnified views (endocytoscopic images) make possible to perform pathological diagnosis only on endo-scopic views of polyps during colonoscopy. However, endocytoscopic image diagnosis requires higher experiences for physicians. An automated pathological diagnosis system is required to prevent the overlooking of neoplastic lesions in endocytoscopy. For this purpose, we propose a new automated endocytoscopic image classification method that classifies neoplastic and non-neoplastic endocytoscopic images. This method consists of two classification steps. At the first step, we classify an input image by support vector machine. We forward the image to the second step if the confidence of the first classification is low. At the second step, we classify the forwarded image by convolutional neural network. We reject the input image if the confidence of the second classification is also low. We experimentally evaluate the classification performance of the proposed method. In this experiment, we use about 16,000 and 4,000 colorectal endocytoscopic images as training and test data, respectively. The results show that the proposed method achieves high sensitivity 93.4% with small rejection rate 9.3% even for difficult test data.

A portable high-definition electronic endoscope based on embedded system

NASA Astrophysics Data System (ADS)

Xu, Guang; Wang, Liqiang; Xu, Jin

2012-11-01

This paper presents a low power and portable highdefinition (HD) electronic endoscope based on CortexA8 embedded system. A 1/6 inch CMOS image sensor is used to acquire HD images with 1280 *800 pixels. The camera interface of A8 is designed to support images of various sizes and support multiple inputs of video format such as ITUR BT601/ 656 standard. Image rotation (90 degrees clockwise) and image process functions are achieved by CAMIF. The decode engine of the processor plays back or records HD videos at speed of 30 frames per second, builtin HDMI interface transmits high definition images to the external display. Image processing procedures such as demosaicking, color correction and auto white balance are realized on the A8 platform. Other functions are selected through OSD settings. An LCD panel displays the real time images. The snapshot pictures or compressed videos are saved in an SD card or transmited to a computer through USB interface. The size of the camera head is 4×4.8×15 mm with more than 3 meters working distance. The whole endoscope system can be powered by a lithium battery, with the advantages of miniature, low cost and portability.

Pilot-study on the feasibility of sentinel node navigation surgery in combination with thoracolaparoscopic lymphadenectomy without esophagectomy in early esophageal adenocarcinoma patients.

PubMed

Künzli, H T; van Berge Henegouwen, M I; Gisbertz, S S; van Esser, S; Meijer, S L; Bennink, R J; Wiezer, M J; Seldenrijk, C A; Bergman, J J G H M; Weusten, B L A M

2017-11-01

High-risk submucosal esophageal adenocarcinoma's might be treated curatively by means of radical endoscopic resection, followed by thoracolaparoscopic lymphadenectomy without concomitant esophagectomy. A preclinical study has shown the feasibility and safety of this approach; however, no studies are performed in a clinical setting. In addition, sentinel node navigation surgery could be valuable in tailoring the extent of the lymphadenectomy. This study aimed to evaluate the feasibility and safety of thoracolaparoscopic lymphadenectomy without esophagectomy (phase I) and sentinel node navigation surgery (phase II) in patients with early esophageal adenocarcinoma. Patients with T1N0M0 early esophageal adenocarcinoma scheduled for esophagectomy without neoadjuvant therapy were included. Phase I: Two-field, esophagus preserving, thoracolaparoscopic lymphadenectomy was performed, followed by esophagectomy in the same session. Primary outcome parameters were the number of lymph nodes resected, and number of retained lymph nodes in the esophagectomy specimen. Phase II: A radioactive tracer was injected endoscopically the day before surgery. Static imaging was performed 15 and 120 minutes after injection. The day of surgery, sentinel node navigation surgery followed by esophagectomy was performed. Primary outcome parameters were the percentage of patients with a detectable sentinel node, and the concordance between static imaging and probe-based detection of sentinel node. Phase I: Five patients were included, and a median of 30 (IQR: 25-46) lymph nodes was resected. A median of 6 (IQR: 2-9) retained lymph nodes was found in the esophagectomy specimen. No acute adverse events occurred, but near the end of lymphadenectomy esophageal discoloration was observed, possibly indicating ischemia. Phase II: In all five included patients sentinel nodes could be visualized and resected, at a median of 3 (IQR: 2-5) locations. There was a high concordance between imaging and probe-based detection of sentinel nodes. In conclusion, sentinel node navigation surgery followed by lymphadenectomy without concomitant esophagectomy seems feasible in patients with high-risk submucosal early esophageal adenocarcinoma. More evidence is however needed before applying this technique in clinical practice. © The Authors 2017. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

PubMed

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.

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

PubMed

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.

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

PubMed Central

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

An ultra-low-power image compressor for capsule endoscope.

PubMed

Lin, Meng-Chun; Dung, Lan-Rong; Weng, Ping-Kuo

2006-02-25

Gastrointestinal (GI) endoscopy has been popularly applied for the diagnosis of diseases of the alimentary canal including Crohn's Disease, Celiac disease and other malabsorption disorders, benign and malignant tumors of the small intestine, vascular disorders and medication related small bowel injury. The wireless capsule endoscope has been successfully utilized to diagnose diseases of the small intestine and alleviate the discomfort and pain of patients. However, the resolution of demosaicked image is still low, and some interesting spots may be unintentionally omitted. Especially, the images will be severely distorted when physicians zoom images in for detailed diagnosis. Increasing resolution may cause significant power consumption in RF transmitter; hence, image compression is necessary for saving the power dissipation of RF transmitter. To overcome this drawback, we have been developing a new capsule endoscope, called GICam. We developed an ultra-low-power image compression processor for capsule endoscope or swallowable imaging capsules. In applications of capsule endoscopy, it is imperative to consider battery life/performance trade-offs. Applying state-of-the-art video compression techniques may significantly reduce the image bit rate by their high compression ratio, but they all require intensive computation and consume much battery power. There are many fast compression algorithms for reducing computation load; however, they may result in distortion of the original image, which is not good for use in the medical care. Thus, this paper will first simplify traditional video compression algorithms and propose a scalable compression architecture. As the result, the developed video compressor only costs 31 K gates at 2 frames per second, consumes 14.92 mW, and reduces the video size by 75% at least.

Dual-Channel Endoscopic Indocyanine Green Fluorescence Angiography for Clipping of Cerebral Aneurysms.

PubMed

Cho, Won-Sang; Kim, Jeong Eun; Kang, Hyun-Seung; Ha, Eun Jin; Jung, Minwoong; Lee, Choonghee; Shin, Il Hyung; Kang, Uk

2017-04-01

Neuroendoscopy is useful for assessing status of perforators, parent arteries, and aneurysms beyond the straight line of microscopic view during aneurysm clipping. We aimed to evaluate the clinical usefulness of our endoscopic indocyanine green angiography (ICGA) system, which can simultaneously display visible light and indocyanine green fluorescent images. Surgical clipping of 16 unruptured aneurysms in 10 patients was performed via the keyhole approach. Using our endoscopic ICGA and commercial microscopic ICGA systems, we prospectively compared 10 targeted cerebral aneurysms at the posterior communicating (n = 4) and anterior choroidal (n = 6) arteries. Microscopic ICGA and endoscopic ICGA were feasible during surgery. Microscopic ICGA displayed 50% of branch orifices, 100% of branch trunks, and 20% of exact clip positions, whereas endoscopic ICGA showed 100% of these. Based on endoscopic ICGA findings such as incomplete clipping and compromise of parent arteries or branches, clips were repositioned in 2 cases, and additional clips were applied in 2 cases. Complete occlusion and residual neck states were achieved in 6 and 4 aneurysms after surgery. There were no neurologic deficits within 3 months after surgery except for frontalis palsy and anosmia in each patient. The endoscopic ICGA system with dual imaging of visible light and indocyanine green fluorescence was very useful for assessing geometry of aneurysms and surrounding vessels before clipping and for evaluating completeness of clip position after clipping. Copyright © 2017 Elsevier Inc. All rights reserved.

Molecular Imaging: Current Status and Emerging Strategies

PubMed Central

Pysz, Marybeth A.; Gambhir, Sanjiv S.; Willmann, Jürgen K.

2011-01-01

In vivo molecular imaging has a great potential to impact medicine by detecting diseases in early stages (screening), identifying extent of disease, selecting disease- and patient-specific therapeutic treatment (personalized medicine), applying a directed or targeted therapy, and measuring molecular-specific effects of treatment. Current clinical molecular imaging approaches primarily use PET- or SPECT-based techniques. In ongoing preclinical research novel molecular targets of different diseases are identified and, sophisticated and multifunctional contrast agents for imaging these molecular targets are developed along with new technologies and instrumentation for multimodality molecular imaging. Contrast-enhanced molecular ultrasound with molecularly-targeted contrast microbubbles is explored as a clinically translatable molecular imaging strategy for screening, diagnosing, and monitoring diseases at the molecular level. Optical imaging with fluorescent molecular probes and ultrasound imaging with molecularly-targeted microbubbles are attractive strategies since they provide real-time imaging, are relatively inexpensive, produce images with high spatial resolution, and do not involve exposure to ionizing irradiation. Raman spectroscopy/microscopy has emerged as a molecular optical imaging strategy for ultrasensitive detection of multiple biomolecules/biochemicals with both in vivo and ex vivo versatility. Photoacoustic imaging is a hybrid of optical and ultrasound modalities involving optically-excitable molecularly-targeted contrast agents and quantitative detection of resulting oscillatory contrast agent movement with ultrasound. Current preclinical findings and advances in instrumentation such as endoscopes and microcatheters suggest that these molecular imaging modalities have numerous clinical applications and will be translated into clinical use in the near future. PMID:20541650

Biophotonic endoscopy: a review of clinical research techniques for optical imaging and sensing of early gastrointestinal cancer

PubMed Central

Coda, Sergio; Siersema, Peter D.; Stamp, Gordon W. H.; Thillainayagam, Andrew V.

2015-01-01

Detection, characterization, and staging constitute the fundamental elements in the endoscopic diagnosis of gastrointestinal diseases, but histology still remains the diagnostic gold standard. New developments in endoscopic techniques may challenge histopathology in the near future. An ideal endoscopic technique should combine a wide-field, “red flag” screening technique with an optical contrast or microscopy method for characterization and staging, all simultaneously available during the procedure. In theory, biophotonic advances have the potential to unite these elements to allow in vivo “optical biopsy.” These techniques may ultimately offer the potential to increase the rates of detection of high risk lesions and the ability to target biopsies and resections, and so reduce the need for biopsy, costs, and uncertainty for patients. However, their utility and sensitivity in clinical practice must be evaluated against those of conventional histopathology. This review describes some of the most recent applications of biophotonics in endoscopic optical imaging and metrology, along with their fundamental principles and the clinical experience that has been acquired in their deployment as tools for the endoscopist. Particular emphasis has been placed on translational label-free optical techniques, such as fluorescence spectroscopy, fluorescence lifetime imaging microscopy (FLIM), two-photon and multi-photon microscopy, second harmonic generation (SHG) and third harmonic generation (THG) imaging, optical coherence tomography (OCT), diffuse reflectance, Raman spectroscopy, and molecular imaging. PMID:26528489

Fluoroscopy-Guided Endoscopic Removal of Foreign Bodies.

PubMed

Kim, Junhwan; Ahn, Ji Yong; So, Seol; Lee, Mingee; Oh, Kyunghwan; Jung, Hwoon-Yong

2017-03-01

In most cases of ingested foreign bodies, endoscopy is the first treatment of choice. Moreover, emergency endoscopic removal is required for sharp and pointed foreign bodies such as animal or fish bones, food boluses, and button batteries due to the increased risks of perforation, obstruction, and bleeding. Here, we presented two cases that needed emergency endoscopic removal of foreign bodies without sufficient fasting time. Foreign bodies could not be visualized by endoscopy due to food residue; therefore, fluoroscopic imaging was utilized for endoscopic removal of foreign bodies in both cases.

Fluorescence-Raman Dual Modal Endoscopic System for Multiplexed Molecular Diagnostics

NASA Astrophysics Data System (ADS)

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.

3D endoscopic imaging using structured illumination technique (Conference Presentation)

NASA Astrophysics Data System (ADS)

Le, Hanh N. D.; Nguyen, Hieu; Wang, Zhaoyang; Kang, Jin U.

2017-02-01

Surgeons have been increasingly relying on minimally invasive surgical guidance techniques not only to reduce surgical trauma but also to achieve accurate and objective surgical risk evaluations. A typical minimally invasive surgical guidance system provides visual assistance in two-dimensional anatomy and pathology of internal organ within a limited field of view. In this work, we propose and implement a structure illumination endoscope to provide a simple, inexpensive 3D endoscopic imaging to conduct high resolution 3D imagery for use in surgical guidance system. The system is calibrated and validated for quantitative depth measurement in both calibrated target and human subject. The system exhibits a depth of field of 20 mm, depth resolution of 0.2mm and a relative accuracy of 0.1%. The demonstrated setup affirms the feasibility of using the structured illumination endoscope for depth quantization and assisting medical diagnostic assessments

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

NASA Astrophysics Data System (ADS)

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

2018-02-01

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 and a higher order mode fibre with anomalous dispersion properties, fused in series using a long period grating. We show that using this fibre assembly, a simple and robust pulsed laser delivery system without any free-space optics, which is thus suitable for clinical use, can be realised.

Optical design of a dual wave band catadioptric endoscope for the Joint European Torus

NASA Astrophysics Data System (ADS)

Greco, Vincenzo; Maddaluno, Giorgio

2004-02-01

In this paper we describe the optical design of a catadioptric endoscope for the Joint European Torus (JET). The JET is the flagship experiment in the European nuclear fusion research programme. It is a large tokamak (Russian acronym for "toroidal magnetic chamber") system located at Culham (UK). At the centre of this machine there is a toroidal (ring - shaped) vacuum vessel where the plasma is confined by magnetic fields. The endoscope explores in two wave bands (4.2 μm - 4.4 μm and 0.6 μm - 0.7 μm) an entire cross section of the vacuum vessel. It then creates for each wave band an image onto a separate area image sensor, located 5500 mm away from the plasma behind a concrete shield. The endoscope performs two different functions namely: infrared thermography on plasma facing components and in vessel inspection.

Endoscopic management of chronic radiation proctitis

PubMed Central

Rustagi, Tarun; Mashimo, Hiroshi

2011-01-01

Chronic radiation proctopathy occurs in 5%-20% of patients following pelvic radiotherapy. Although many cases resolve spontaneously, some lead to chronic symptoms including diarrhea, tenesmus, urgency and persistent rectal bleeding with iron deficiency anemia requiring blood transfusions. Treatments for chronic radiation proctitis remain unsatisfactory and the basis of evidence for various therapies is generally insufficient. There are very few controlled or prospective trials, and comparisons between therapies are limited because of different evaluation methods. Medical treatments, including formalin, topical sucralfate, 5-amino salicylic acid enemas, and short chain fatty acids have been used with limited success. Surgical management is associated with high morbidity and mortality. Endoscopic therapy using modalities such as the heater probe, neodymium:yttrium-aluminium-garnet laser, potassium titanyl phosphate laser and bipolar electrocoagulation has been reported to be of some benefit, but with frequent complications. Argon plasma coagulation is touted to be the preferred endoscopic therapy due to its efficacy and safety profile. Newer methods of endoscopic ablation such as radiofrequency ablation and cryotherapy have been recently described which may afford broader areas of treatment per application, with lower rate of complications. This review will focus on endoscopic ablation therapies, including such newer modalities, for chronic radiation proctitis. PMID:22147960

Endoscopic management of chronic radiation proctitis.

PubMed

Rustagi, Tarun; Mashimo, Hiroshi

2011-11-07

Chronic radiation proctopathy occurs in 5%-20% of patients following pelvic radiotherapy. Although many cases resolve spontaneously, some lead to chronic symptoms including diarrhea, tenesmus, urgency and persistent rectal bleeding with iron deficiency anemia requiring blood transfusions. Treatments for chronic radiation proctitis remain unsatisfactory and the basis of evidence for various therapies is generally insufficient. There are very few controlled or prospective trials, and comparisons between therapies are limited because of different evaluation methods. Medical treatments, including formalin, topical sucralfate, 5-amino salicylic acid enemas, and short chain fatty acids have been used with limited success. Surgical management is associated with high morbidity and mortality. Endoscopic therapy using modalities such as the heater probe, neodymium:yttrium-aluminium-garnet laser, potassium titanyl phosphate laser and bipolar electrocoagulation has been reported to be of some benefit, but with frequent complications. Argon plasma coagulation is touted to be the preferred endoscopic therapy due to its efficacy and safety profile. Newer methods of endoscopic ablation such as radiofrequency ablation and cryotherapy have been recently described which may afford broader areas of treatment per application, with lower rate of complications. This review will focus on endoscopic ablation therapies, including such newer modalities, for chronic radiation proctitis.

Endoscopic ultrasound-guided techniques for diagnosing pancreatic mass lesions: Can we do better?

PubMed Central

Storm, Andrew C; Lee, Linda S

2016-01-01

The diagnostic approach to a possible pancreatic mass lesion relies first upon various non-invasive imaging modalities, including computed tomography, ultrasound, and magnetic resonance imaging techniques. Once a suspect lesion has been identified, tissue acquisition for characterization of the lesion is often paramount in developing an individualized therapeutic approach. Given the high prevalence and mortality associated with pancreatic cancer, an ideal approach to diagnosing pancreatic mass lesions would be safe, highly sensitive, and reproducible across various practice settings. Tools, in addition to radiologic imaging, currently employed in the initial evaluation of a patient with a pancreatic mass lesion include serum tumor markers, endoscopic retrograde cholangiopancreatography, and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). EUS-FNA has grown to become the gold standard in tissue diagnosis of pancreatic lesions. PMID:27818584

Fluorescence endoscopy using fiber speckle illumination

NASA Astrophysics Data System (ADS)

Nakano, Shuhei; Katagiri, Takashi; Matsuura, Yuji

2018-02-01

An endoscopic fluorescence imaging system based on fiber speckle illumination is proposed. In this system, a multimode fiber for transmission of excitation laser light and collection of fluorescence is inserted into a conventional flexible endoscope. Since the excitation laser light has random speckle structure, one can detect fluorescence signal corresponding to the irradiation pattern if the sample contains fluorophores. The irradiation pattern can be captured by the endoscope camera when the excitation wavelength is within the sensitivity range of the camera. By performing multiple measurements while changing the irradiation pattern, a fluorescence image is reconstructed by solving a norm minimization problem. The principle of our method was experimentally demonstrated. A 2048 pixels image of quantum dots coated on a frosted glass was successfully reconstructed by 32 measurements. We also confirmed that our method can be applied on biological tissues.

Design of wormlike automated robotic endoscope: dynamic interaction between endoscopic balloon and surrounding tissues.

PubMed

Poon, Carmen C Y; Leung, Billy; Chan, Cecilia K W; Lau, James Y W; Chiu, Philip W Y

2016-02-01

The current design of capsule endoscope is limited by the inability to control the motion within gastrointestinal tract. The rising incidence of gastrointestinal cancers urged improvement in the method of screening endoscopy. This preclinical study aimed to design and develop a novel locomotive module for capsule endoscope. We investigated the feasibility and physical properties of this newly designed caterpillar-like capsule endoscope with a view to enhancing screening endoscopy. This study consisted of preclinical design and experimental testing on the feasibility of automated locomotion for a prototype caterpillar endoscope. The movement was examined first in the PVC tube and then in porcine intestine. The image captured was transmitted to handheld device to confirm the control of movement. The balloon pressure and volume as well as the contact force between the balloon and surroundings were measured when the balloon was inflated inside (1) a hard PVC tube, (2) a soft PVC tube, (3) muscular sites of porcine colons and (4) less muscular sites of porcine colons. The prototype caterpillar endoscope was able to move inward and backward within the PVC tubing and porcine intestine. Images were able to be captured from the capsule endoscope attached and being observed with a handheld device. Using the onset of a contact force as indication of the buildup of the gripping force between the balloon and the lumen walls, it is concluded from the results of this study that the rate of change in balloon pressure and volume is two good estimators to optimize the inflation of the balloon. The results of this study will facilitate further refinement in the design of caterpillar robotic endoscope to move inside the GI tract.

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

NASA Astrophysics Data System (ADS)

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.

Applications of rigid and flexible GRIN-endoscopes

NASA Astrophysics Data System (ADS)

Schenkl, Selma; Ehlers, Alexander; Riemann, Iris; Messerschmidt, Bernhard; Bückle, Rainer; König, Karsten

2007-02-01

Multiphoton autofluorescence imaging became an important technique for minimal invasive examination of cells in biological tissue. Rigid and flexible endoscopes based on gradient index lenses (GRIN-lenses) extend this minimalinvasive technique to deep lying cell layers, inner body and specimens, difficult to access. In the rigid endoscope, a GRIN-lens overcomes the limited depth range, given by the working distance of the microscope objective. The focus of the conventional laser scanning tomography is reproduced tens of millimeters in the specimen under study by the GRIN-lens (diameter 1.8 and 3 μm). We will present images of fluorescent beads, proteins cells and skin tissue, as well as first in vivo measurements on human skin. The autofluorescence signal stems from the endogenous fluorophore elastin and SHG from collagen. The flexible endoscope dispenses completely the need of a microscope next to the specimen of interest. The excitation laser pulses is delivered via a well-characterized photonic crystal fiber and subsequently focused by a newly designed GRIN-lens system. The fluorescence, also transferred by a fiber is detected by a PMT detector. We will show the excellent imaging qualities of a newly developed GRIN-lens system with high-resolution images of proteins, cells and plant tissue and give an out-look on multiphoton endoscopy.

Design and validation of a near-infrared fluorescence endoscope for detection of early esophageal malignancy

NASA Astrophysics Data System (ADS)

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

2016-08-01

Barrett's esophagus is a known precursor lesion to esophageal adenocarcinoma. In these patients, early detection of premalignant disease, known as dysplasia, allows curative minimally invasive endoscopic therapy, but is confounded by a lack of contrast in white light endoscopy. Imaging fluorescently labeled lectins applied topically to the tissue has the potential to more accurately delineate dysplasia, but tissue autofluorescence limits both sensitivity and contrast when operating in the visible region. To overcome this challenge, we synthesized near-infrared (NIR) fluorescent wheat germ agglutinin (WGA-IR800CW) and constructed a clinically translatable bimodal NIR and white light endoscope. Images of NIR and white light with a field of view of 63 deg and an image resolution of 182 μm are coregistered and the honeycomb artifact arising from the fiber bundle is removed. A minimum detectable concentration of 110 nM was determined using a dilution series of WGA-IR800CW. We demonstrated ex vivo that this system can distinguish between gastric and squamous tissue types in mouse stomachs (p=0.0005) and accurately detect WGA-IR800CW fluorescence in human esophageal resections (compared with a gold standard imaging system, rs>0.90). Based on these findings, future work will optimize the bimodal endoscopic system for clinical trials in Barrett's surveillance.

Endoscopic Therapy in Crohn's Disease: Principle, Preparation, and Technique.

PubMed

Chen, Min; Shen, Bo

2015-09-01

Stricture and fistula are common complications of Crohn's disease. Endoscopic balloon dilation and needle-knife stricturotomy has become a valid treatment option for Crohn's disease-associated strictures. Endoscopic therapy is also increasingly used in Crohn's disease-associated fistula. Preprocedural preparations, including routine laboratory testing, imaging examination, anticoagulant management, bowel cleansing and proper sedation, are essential to ensure a successful and safe endoscopic therapy. Adverse events, such as perforation and excessive bleeding, may occur during endoscopic intervention. The endoscopist should be well trained, always be cautious, anticipate for possible procedure-associated complications, be prepared for damage control during endoscopy, and have surgical backup ready. In this review, we discuss the principle, preparation, techniques of endoscopic therapy, as well as the prevention and management of endoscopic procedure-associated complications. We propose that inflammatory bowel disease endoscopy may be a part of training for "super" gastroenterology fellows, i.e., those seeking a career in advanced endoscopy or in inflammatory bowel disease.

Optical coherence tomography vs. high-frequency ultrasound during noninvasive laser coagulation of the canine vas deferens

NASA Astrophysics Data System (ADS)

Cilip, Christopher M.; Allaf, Mohamad E.; Fried, Nathaniel M.

2012-02-01

A noninvasive approach to vasectomy may eliminate male fear of complications related to surgery and increase its acceptance. Noninvasive laser thermal occlusion of the canine vas deferens has recently been reported. In this study, optical coherence tomography (OCT) and high-frequency ultrasound (HFUS) are compared for monitoring laser thermal coagulation of the vas in an acute canine model. Bilateral noninvasive laser coagulation of the vas was performed in 6 dogs (n=12 vasa) using a Ytterbium fiber laser wavelength of 1075 nm, incident power of 9.0 W, pulse duration of 500 ms, pulse rate of 1 Hz, and 3-mm-diameter spot. Cryogen spray cooling was used to prevent skin burns during the procedure. An OCT system with endoscopic probe and a HFUS system with 20-MHz transducer were used to image the vas immediately before and after the procedure. Vasa were then excised and processed for gross and histologic analysis for comparison with OCT and HFUS images. OCT provided high-resolution, superficial imaging of the compressed vas within the vas ring clamp, while HFUS provided deeper imaging of the vas held manually in the scrotal fold. Both OCT and high HFUS are promising imaging modalities for real-time confirmation of vas occlusion during noninvasive laser vasectomy.

Wireless technologies for robotic endoscope in gastrointestinal tract.

PubMed

Gao, P; Yan, G; Wang, Z; Liu, H

2012-07-01

This paper introduces wireless technologies for use with robotic endoscopes in the gastrointestinal tract. The technologies include wireless power transmission (WPT), wireless remote control (WRC), and wireless image transmission (WIT). WPT, based on the electromagnetic coupling principle, powers active locomotion actuators and other peripherals in large air gaps. WRC, based on real-time bidirectional communication, has a multikernel frame in vivo to realize real-time multitasking. WIT provides a continuous dynamic image with a revolution of 320 × 240 pixel at 30 fps for in vitro diagnosis. To test these wireless technologies, three robotic endoscope prototypes were fabricated and equipped with the customized modules. The experimental results show that the wireless technologies have value for clinical applications.

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

PubMed Central

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

Design of illumination system in ring field capsule endoscope

NASA Astrophysics Data System (ADS)

Jeng, Wei-De; Mang, Ou-Yang; Chen, Yu-Ta; Wu, Ying-Yi

2011-03-01

This paper is researching about the illumination system in ring field capsule endoscope. It is difficult to obtain the uniform illumination on the observed object because the light intensity of LED will be changed along its angular displacement and same as luminous intensity distribution curve. So we use the optical design software which is Advanced Systems Analysis Program (ASAP) to build a photometric model for the optimal design of LED illumination system in ring field capsule endoscope. In this paper, the optimal design of illumination uniformity in the ring field capsule endoscope is from origin 0.128 up to optimum 0.603 and it would advance the image quality of ring field capsule endoscope greatly.

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

PubMed

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.

Upper Nasopharyngeal Corridor for Transnasal Endoscopic Drainage of Petroclival Cholesterol Granulomas: Alternative Access in Conchal Sphenoid Patients.

PubMed

Turan, Nefize; Baum, Griffin R; Holland, Christopher M; Ahmad, Faiz U; Henriquez, Oswaldo A; Pradilla, Gustavo

2016-03-01

Background Cholesterol granulomas arising at the petrous apex can be treated via traditional open surgical, endoscopic, and endoscopic-assisted approaches. Endoscopic approaches require access to the sphenoid sinus, which is technically challenging in patients with conchal sphenoidal anatomy. Clinical Presentation A 55-year-old woman presented with intermittent headaches and tinnitus. Formal audiometry demonstrated moderately severe bilateral hearing loss. CT of the temporal bones and sella revealed a well-demarcated expansile lytic mass. MRI of the face, orbit, and neck showed a right petrous apex mass measuring 22 × 18 × 19 mm that was hyperintense on T1- and T2-weighted images without enhancement, consistent with a cholesterol granuloma. The patient had a conchal sphenoidal anatomy. Operative Technique Herein, we present an illustrative case of a low-lying petroclival cholesterol granuloma in a patient with conchal sphenoidal anatomy to describe an alternative high nasopharyngeal corridor for endoscopic transnasal transclival access. Postoperative Course Postoperatively, the patient's symptoms recovered and no complications occurred. Follow-up imaging demonstrated a patent drainage tract without evidence of recurrence. Conclusion In patients with a conchal sphenoid sinus, endoscopic transnasal transclival access can be gained using a high nasopharyngeal approach. This corridor facilitates safe access to these lesions and others in this location.

Optical Biopsy: A New Frontier in Endoscopic Detection and Diagnosis

PubMed Central

WANG, THOMAS D.; VAN DAM, JACQUES

2007-01-01

Endoscopic diagnosis currently relies on the ability of the operator to visualize abnormal patterns in the image created by light reflected from the mucosal surface of the gastrointestinal tract. Advances in fiber optics, light sources, detectors, and molecular biology have led to the development of several novel methods for tissue evaluation in situ. The term “optical biopsy” refers to methods that use the properties of light to enable the operator to make an instant diagnosis at endoscopy, previously possible only by using histological or cytological analysis. Promising imaging techniques include fluorescence endoscopy, optical coherence tomography, confocal microendoscopy, and molecular imaging. Point detection schemes under development include light scattering and Raman spectroscopy. Such advanced diagnostic methods go beyond standard endoscopic techniques by offering improved image resolution, contrast, and tissue penetration and providing biochemical and molecular information about mucosal disease. This review describes the basic biophysics of light-tissue interactions, assesses the strengths and weaknesses of each method, and examines clinical and preclinical evidence for each approach. PMID:15354274

[Design and Implementation of Image Interpolation and Color Correction for Ultra-thin Electronic Endoscope on FPGA].

PubMed

Luo, Qiang; Yan, Zhuangzhi; Gu, Dongxing; Cao, Lei

This paper proposed an image interpolation algorithm based on bilinear interpolation and a color correction algorithm based on polynomial regression on FPGA, which focused on the limited number of imaging pixels and color distortion of the ultra-thin electronic endoscope. Simulation experiment results showed that the proposed algorithm realized the real-time display of 1280 x 720@60Hz HD video, and using the X-rite color checker as standard colors, the average color difference was reduced about 30% comparing with that before color correction.

Miniature objective lens with variable focus for confocal endomicroscopy

PubMed Central

Kim, Minkyu; Kang, DongKyun; Wu, Tao; Tabatabaei, Nima; Carruth, Robert W.; Martinez, Ramses V; Whitesides, George M.; Nakajima, Yoshikazu; Tearney, Guillermo J.

2014-01-01

Spectrally encoded confocal microscopy (SECM) is a reflectance confocal microscopy technology that can rapidly image large areas of luminal organs at microscopic resolution. One of the main challenges for large-area SECM imaging in vivo is maintaining the same imaging depth within the tissue when patient motion and tissue surface irregularity are present. In this paper, we report the development of a miniature vari-focal objective lens that can be used in an SECM endoscopic probe to conduct adaptive focusing and to maintain the same imaging depth during in vivo imaging. The vari-focal objective lens is composed of an aspheric singlet with an NA of 0.5, a miniature water chamber, and a thin elastic membrane. The water volume within the chamber was changed to control curvature of the elastic membrane, which subsequently altered the position of the SECM focus. The vari-focal objective lens has a diameter of 5 mm and thickness of 4 mm. A vari-focal range of 240 μm was achieved while maintaining lateral resolution better than 2.6 μm and axial resolution better than 26 μm. Volumetric SECM images of swine esophageal tissues were obtained over the vari-focal range of 260 μm. SECM images clearly visualized cellular features of the swine esophagus at all focal depths, including basal cell nuclei, papillae, and lamina propria. PMID:25574443

Endoscopic Endonasal Approach for a Suprasellar Craniopharyngioma.

PubMed

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 .

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

NASA Astrophysics Data System (ADS)

Frisch, Benjamin

2013-12-01

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 detector system with a CTR better than 240 ps FWHM. We discuss the challenges in simulating such a system and introduce reconstruction algorithms based on graphics processing units (GPU).

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ingram, W; Yang, J; Beadle, B

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 themore » 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 Tracking is sensitive to erratic camera motion and local optima, but could be used in conjunction with anchor points found using Location Search.« less

Excitation-scanning hyperspectral imaging system for microscopic and endoscopic applications

NASA Astrophysics Data System (ADS)

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.

Asia-Pacific working group consensus on non-variceal upper gastrointestinal bleeding: an update 2018.

PubMed

Sung, Joseph Jy; Chiu, Philip Cy; Chan, Francis K L; Lau, James Yw; Goh, Khean-Lee; Ho, Lawrence Hy; Jung, Hwoon-Young; Sollano, Jose D; Gotoda, Takuji; Reddy, Nageshwar; Singh, Rajvinder; Sugano, Kentaro; Wu, Kai-Chun; Wu, Chun-Yin; Bjorkman, David J; Jensen, Dennis M; Kuipers, Ernst J; Lanas, Angel

2018-04-24

Non-variceal upper gastrointestinal bleeding remains an important emergency condition, leading to significant morbidity and mortality. As endoscopic therapy is the 'gold standard' of management, treatment of these patients can be considered in three stages: pre-endoscopic treatment, endoscopic haemostasis and post-endoscopic management. Since publication of the Asia-Pacific consensus on non-variceal upper gastrointestinal bleeding (NVUGIB) 7 years ago, there have been significant advancements in the clinical management of patients in all three stages. These include pre-endoscopy risk stratification scores, blood and platelet transfusion, use of proton pump inhibitors; during endoscopy new haemostasis techniques (haemostatic powder spray and over-the-scope clips); and post-endoscopy management by second-look endoscopy and medication strategies. Emerging techniques, including capsule endoscopy and Doppler endoscopic probe in assessing adequacy of endoscopic therapy, and the pre-emptive use of angiographic embolisation, are attracting new attention. An emerging problem is the increasing use of dual antiplatelet agents and direct oral anticoagulants in patients with cardiac and cerebrovascular diseases. Guidelines on the discontinuation and then resumption of these agents in patients presenting with NVUGIB are very much needed. The Asia-Pacific Working Group examined recent evidence and recommends practical management guidelines in this updated consensus statement. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Advanced Image Enhancement Method for Distant Vessels and Structures in Capsule Endoscopy

PubMed Central

Pedersen, Marius

2017-01-01

This paper proposes an advanced method for contrast enhancement of capsule endoscopic images, with the main objective to obtain sufficient information about the vessels and structures in more distant (or darker) parts of capsule endoscopic images. The proposed method (PM) combines two algorithms for the enhancement of darker and brighter areas of capsule endoscopic images, respectively. The half-unit weighted-bilinear algorithm (HWB) proposed in our previous work is used to enhance darker areas according to the darker map content of its HSV's component V. Enhancement of brighter areas is achieved thanks to the novel threshold weighted-bilinear algorithm (TWB) developed to avoid overexposure and enlargement of specular highlight spots while preserving the hue, in such areas. The TWB performs enhancement operations following a gradual increment of the brightness of the brighter map content of its HSV's component V. In other words, the TWB decreases its averaged weights as the intensity content of the component V increases. Extensive experimental demonstrations were conducted, and, based on evaluation of the reference and PM enhanced images, a gastroenterologist (Ø.H.) concluded that the PM enhanced images were the best ones based on the information about the vessels, contrast in the images, and the view or visibility of the structures in more distant parts of the capsule endoscopy images. PMID:29225668

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

PubMed

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.

Analysis and design of stereoscopic display in stereo television endoscope system

NASA Astrophysics Data System (ADS)

Feng, Dawei

2008-12-01

Many 3D displays have been proposed for medical use. When we design and evaluate new system, there are three demands from surgeons. Priority is the precision. Secondly, displayed images should be easy to understand, In addition, surgery lasts hours and hours, they do not like fatiguing display. The stereo television endoscope researched in this paper make celiac viscera image on the photosurface of the left and right CCD by imitating human binocular stereo vision effect by using the double-optical lines system. The left and right video signal will be processed by frequency multiplication and display on the monitor, people can observe the stereo image which has depth impression by using a polarized LCD screen and a pair of polarized glasses. Clinical experiments show that by using the stereo TV endoscope people can make minimally invasive surgery more safe and reliable, and can shorten the operation time, and can improve the operation accuracy.

Single lens system for forward-viewing navigation and scanning side-viewing optical coherence tomography

NASA Astrophysics Data System (ADS)

Tate, Tyler H.; McGregor, Davis; Barton, Jennifer K.

2017-02-01

The optical design for a dual modality endoscope based on piezo scanning fiber technology is presented including a novel technique to combine forward-viewing navigation and side viewing OCT. Potential applications include navigating body lumens such as the fallopian tube, biliary ducts and cardiovascular system. A custom cover plate provides a rotationally symmetric double reflection of the OCT beam to deviate and focus the OCT beam out the side of the endoscope for cross-sectional imaging of the tubal lumen. Considerations in the choice of the scanning fiber are explored and a new technique to increase the divergence angle of the scanning fiber to improve system performance is presented. Resolution and the necessary scanning density requirements to achieve Nyquist sampling of the full image are considered. The novel optical design lays the groundwork for a new approach integrating side-viewing OCT into multimodality endoscopes for small lumen imaging. KEYWORDS:

Two-photon microscopy using fiber-based nanosecond excitation.

PubMed

Karpf, Sebastian; Eibl, Matthias; Sauer, Benjamin; Reinholz, Fred; Hüttmann, Gereon; Huber, Robert

2016-07-01

Two-photon excitation fluorescence (TPEF) microscopy is a powerful technique for sensitive tissue imaging at depths of up to 1000 micrometers. However, due to the shallow penetration, for in vivo imaging of internal organs in patients beam delivery by an endoscope is crucial. Until today, this is hindered by linear and non-linear pulse broadening of the femtosecond pulses in the optical fibers of the endoscopes. Here we present an endoscope-ready, fiber-based TPEF microscope, using nanosecond pulses at low repetition rates instead of femtosecond pulses. These nanosecond pulses lack most of the problems connected with femtosecond pulses but are equally suited for TPEF imaging. We derive and demonstrate that at given cw-power the TPEF signal only depends on the duty cycle of the laser source. Due to the higher pulse energy at the same peak power we can also demonstrate single shot two-photon fluorescence lifetime measurements.

Fast calibration of electromagnetically tracked oblique-viewing rigid endoscopes.

PubMed

Liu, Xinyang; Rice, Christina E; Shekhar, Raj

2017-10-01

The oblique-viewing (i.e., angled) rigid endoscope is a commonly used tool in conventional endoscopic surgeries. The relative rotation between its two moveable parts, the telescope and the camera head, creates a rotation offset between the actual and the projection of an object in the camera image. A calibration method tailored to compensate such offset is needed. We developed a fast calibration method for oblique-viewing rigid endoscopes suitable for clinical use. In contrast to prior approaches based on optical tracking, we used electromagnetic (EM) tracking as the external tracking hardware to improve compactness and practicality. Two EM sensors were mounted on the telescope and the camera head, respectively, with considerations to minimize EM tracking errors. Single-image calibration was incorporated into the method, and a sterilizable plate, laser-marked with the calibration pattern, was also developed. Furthermore, we proposed a general algorithm to estimate the rotation center in the camera image. Formulas for updating the camera matrix in terms of clockwise and counterclockwise rotations were also developed. The proposed calibration method was validated using a conventional [Formula: see text], 5-mm laparoscope. Freehand calibrations were performed using the proposed method, and the calibration time averaged 2 min and 8 s. The calibration accuracy was evaluated in a simulated clinical setting with several surgical tools present in the magnetic field of EM tracking. The root-mean-square re-projection error averaged 4.9 pixel (range 2.4-8.5 pixel, with image resolution of [Formula: see text] for rotation angles ranged from [Formula: see text] to [Formula: see text]. We developed a method for fast and accurate calibration of oblique-viewing rigid endoscopes. The method was also designed to be performed in the operating room and will therefore support clinical translation of many emerging endoscopic computer-assisted surgical systems.

Endoscopic placement of the small-bowel video capsule by using a capsule endoscope delivery device.

PubMed

Holden, Jeremy P; Dureja, Parul; Pfau, Patrick R; Schwartz, Darren C; Reichelderfer, Mark; Judd, Robert H; Danko, Istvan; Iyer, Lalitha V; Gopal, Deepak V

2007-05-01

Capsule endoscopy performed via the traditional peroral route is technically challenging in patients with dysphagia, gastroparesis, and/or abnormal upper-GI (UGI) anatomy. To describe the indications and outcomes of cases in which the AdvanCE capsule endoscope delivery device, which has recently been cleared by the Food and Drug Administration, was used. Retrospective, descriptive, case series. Tertiary care, university hospital. We report a case series of 16 consecutive patients in whom the AdvanCE delivery device was used. The study period was May 2005 through July 2006. Endoscopic delivery of the video capsule to the proximal small bowel by using the AdvanCE delivery device. Indications, technique, and completeness of small bowel imaging in patients who underwent endoscopic video capsule delivery. The AdvanCE delivery device was used in 16 patients ranging in age from 3 to 74 years. The primary indications for endoscopic delivery included inability to swallow the capsule (10), altered UGI anatomy (4), and gastroparesis (2). Of the 4 patients with altered UGI anatomy, 3 had dual intestinal loop anatomy (ie, Bilroth-II procedure, Whipple surgery, Roux-en-Y gastric bypass) and 1 had a failed Nissen fundoplication. In all cases, the capsule was easily deployed without complication, and complete small intestinal imaging was achieved. Small patient size. Endoscopic placement of the Given PillCam by use of the AdvanCE delivery device was safe and easily performed in patients for whom capsule endoscopy would otherwise have been contraindicated or technically challenging.

Super-achromatic microprobe for ultrahigh-resolution endoscopic OCT imaging at 800 nm (Conference Presentation)

NASA Astrophysics Data System (ADS)

Yuan, Wu; Alemohammad, Milad; Yu, Xiaoyun; Yu, Shaoyong; Li, Xingde

2016-03-01

In this paper, we report a super-achromatic microprobe made with fiber-optic ball lens to enable ultrahigh-resolution endoscopic OCT imaging. An axial resolution of ~2.4 µm (in air) can be achieved with a 7-fs Ti:Sapphire laser. The microprobe has minimal astigmatism which affords a high transverse resolution of ~5.6 µm. The miniaturized microprobe has an outer diameter of ~520 µm including the encasing metal guard and can be used to image small luminal organs. The performance of the ultrahigh-resolution OCT microprobe was demonstrated by imaging rat esophagus, guinea pig esophagus, and mouse rectum in vivo.

Capsule endoscope localization based on computer vision technique.

PubMed

Liu, Li; Hu, Chao; Cai, Wentao; Meng, Max Q H

2009-01-01

To build a new type of wireless capsule endoscope with interactive gastrointestinal tract examination, a localization and orientation system is needed for tracking 3D location and 3D orientation of the capsule movement. The magnetic localization and orientation method produces only 5 DOF, but misses the information of rotation angle along capsule's main axis. In this paper, we presented a complementary orientation approach for the capsule endoscope, and the 3D rotation can be determined by applying computer vision technique on the captured endoscopic images. The experimental results show that the complementary orientation method has good accuracy and high feasibility.

[Digital imaging and robotics in endoscopic surgery].

PubMed

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).

In vivo imaging of pulmonary nodule and vasculature using endoscopic co-registered optical coherence tomography and autofluorescence imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Pahlevaninezhad, Hamid; Lee, Anthony; Hohert, Geoffrey; Schwartz, Carely; Shaipanich, Tawimas; Ritchie, Alexander J.; Zhang, Wei; MacAulay, Calum E.; Lam, Stephen; Lane, Pierre M.

2016-03-01

Peripheral lung nodules found by CT-scans are difficult to localize and biopsy bronchoscopically particularly for those ≤ 2 cm in diameter. In this work, we present the results of endoscopic co-registered optical coherence tomography and autofluorescence imaging (OCT-AFI) of normal and abnormal peripheral airways from 40 patients using 0.9 mm diameter fiber optic rotary pullback catheter. Optical coherence tomography (OCT) can visualize detailed airway morphology endoscopically in the lung periphery. Autofluorescence imaging (AFI) can visualize fluorescing tissue components such as collagen and elastin, enabling the detection of airway lesions with high sensitivity. Results indicate that AFI of abnormal airways is different from that of normal airways, suggesting that AFI can provide a sensitive visual presentation for rapidly identifying possible sites of pulmonary nodules. AFI can also rapidly visualize in vivo vascular networks using fast scanning parameters resulting in vascular-sensitive imaging with less breathing/cardiac motion artifacts compared to Doppler OCT imaging. It is known that tumor vasculature is structurally and functionally different from normal vessels. Thus, AFI can be potentially used for differentiating normal and abnormal lung vasculature for studying vascular remodeling.

Fibre-optic nonlinear optical microscopy and endoscopy.

PubMed

Fu, L; Gu, M

2007-06-01

Nonlinear optical microscopy has been an indispensable laboratory tool of high-resolution imaging in thick tissue and live animals. Rapid developments of fibre-optic components in terms of growing functionality and decreasing size provide enormous opportunities for innovations in nonlinear optical microscopy. Fibre-based nonlinear optical endoscopy is the sole instrumentation to permit the cellular imaging within hollow tissue tracts or solid organs that are inaccessible to a conventional optical microscope. This article reviews the current development of fibre-optic nonlinear optical microscopy and endoscopy, which includes crucial technologies for miniaturized nonlinear optical microscopy and their embodiments of endoscopic systems. A particular attention is given to several classes of photonic crystal fibres that have been applied to nonlinear optical microscopy due to their unique properties for ultrashort pulse delivery and signal collection. Furthermore, fibre-optic nonlinear optical imaging systems can be classified into portable microscopes suitable for imaging behaving animals, rigid endoscopes that allow for deep tissue imaging with minimally invasive manners, and flexible endoscopes enabling imaging of internal organs. Fibre-optic nonlinear optical endoscopy is coming of age and a paradigm shift leading to optical microscope tools for early cancer detection and minimally invasive surgery.

Towards real time 2D to 3D registration for ultrasound-guided endoscopic and laparoscopic procedures.

PubMed

San José Estépar, Raúl; Westin, Carl-Fredrik; Vosburgh, Kirby G

2009-11-01

A method to register endoscopic and laparoscopic ultrasound (US) images in real time with pre-operative computed tomography (CT) data sets has been developed with the goal of improving diagnosis, biopsy guidance, and surgical interventions in the abdomen. The technique, which has the potential to operate in real time, is based on a new phase correlation technique: LEPART, which specifies the location of a plane in the CT data which best corresponds to the US image. Validation of the method was carried out using an US phantom with cyst regions and with retrospective analysis of data sets from animal model experiments. The phantom validation study shows that local translation displacements can be recovered for each US frame with a root mean squared error of 1.56 +/- 0.78 mm in less than 5 sec, using non-optimized algorithm implementations. A new method for multimodality (preoperative CT and intraoperative US endoscopic images) registration to guide endoscopic interventions was developed and found to be efficient using clinically realistic datasets. The algorithm is inherently capable of being implemented in a parallel computing system so that full real time operation appears likely.

Ultrahigh resolution optical coherence elastography combined with a rigid micro-endoscope (Conference Presentation)

NASA Astrophysics Data System (ADS)

Fang, Qi; Curatolo, Andrea; Wijesinghe, Philip; Hamzah, Juliana; Ganss, Ruth; Noble, Peter B.; Karnowski, Karol; Sampson, David D.; Kim, Jun Ki; Lee, Wei M.; Kennedy, Brendan F.

2017-02-01

The mechanical forces that living cells experience represent an important framework in the determination of a range of intricate cellular functions and processes. Current insight into cell mechanics is typically provided by in vitro measurement systems; for example, atomic force microscopy (AFM) measurements are performed on cells in culture or, at best, on freshly excised tissue. Optical techniques, such as Brillouin microscopy and optical elastography, have been used for ex vivo and in situ imaging, recently achieving cellular-scale resolution. The utility of these techniques in cell mechanics lies in quick, three-dimensional and label-free mechanical imaging. Translation of these techniques toward minimally invasive in vivo imaging would provide unprecedented capabilities in tissue characterization. Here, we take the first steps along this path by incorporating a gradient-index micro-endoscope into an ultrahigh resolution optical elastography system. Using this endoscope, a lateral resolution of 2 µm is preserved over an extended depth-of-field of 80 µm, achieved by Bessel beam illumination. We demonstrate this combined system by imaging stiffness of a silicone phantom containing stiff inclusions and a freshly excised murine liver tissue. Additionally, we test this system on murine ribs in situ. We show that our approach can provide high quality extended depth-of-field images through an endoscope and has the potential to measure cell mechanics deep in tissue. Eventually, we believe this tool will be capable of studying biological processes and disease progression in vivo.

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

PubMed

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.

Endoscopic surgical management of a large Morel-Lavallée lesion.

PubMed

Walls, Andrew; McMahon, Samuel E; MacDonald, Jonathan; Bunn, Jonathan

2017-09-23

The Morel-Lavallée lesion is a closed degloving injury that usually occurs following high-energy trauma. We present a case demonstrating endoscopic management of this lesion. A 44-year-old man fell from scaffolding. Initial assessment demonstrated no significant injury. An ultrasound scan 2 days post injury revealed a large fluid collection along the lateral right thigh. This subsequently became infected and did not respond to antibiotic therapy.Due to the extent of the lesion, we were reluctant to perform a traditional open drainage. An endoscopic probe was inserted at the proximal and distal poles of the lesion and the wound debrided.This resulted in a rapid improvement in symptoms and a complete resolution of the lesion at 1 year postsurgery, with no wound-associated morbidity.This is only the second description of endoscopic debridement of a large, acute Morel-Lavallée lesion, with an excellent outcome. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

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

PubMed Central

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.

PubMed

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

2016-01-01

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.

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

NASA Astrophysics Data System (ADS)

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.

Fluorescence lifetime endoscopy using TCSPC for the measurement of FRET in live cells

PubMed Central

Fruhwirth, Gilbert O.; Ameer-Beg, Simon; Cook, Richard; Watson, Timothy; Ng, Tony; Festy, Frederic

2010-01-01

Development of remote imaging for diagnostic purposes has progressed dramatically since endoscopy began in the 1960’s. The recent advent of a clinically licensed intensity-based fluorescence micro-endoscopic instrument has offered the prospect of real-time cellular resolution imaging. However, interrogating protein-protein interactions deep inside living tissue requires precise fluorescence lifetime measurements to derive the Förster resonance energy transfer between two tagged fluorescent markers. We developed a new instrument combining remote fiber endoscopic cellular-resolution imaging with TCSPC-FLIM technology to interrogate and discriminate mixed fluorochrome labeled beads and expressible GFP/TagRFP tags within live cells. Endoscopic-FLIM (e-FLIM) data was validated by comparison with data acquired via conventional FLIM and e-FLIM was found to be accurate for both bright bead and dim live cell samples. The fiber based micro-endoscope allowed remote imaging of 4 µm and 10 µm beads within a thick Matrigel matrix with confident fluorophore discrimination using lifetime information. More importantly, this new technique enabled us to reliably measure protein-protein interactions in live cells embedded in a 3D matrix, as demonstrated by the dimerization of the fluorescent protein-tagged membrane receptor CXCR4. This cell-based application successfully demonstrated the suitability and great potential of this new technique for in vivo pre-clinical biomedical and possibly human clinical applications. PMID:20588974

New flexible endoscope for otologic application

NASA Astrophysics Data System (ADS)

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.

Optic Nerve Atrophy Due to Long-Standing Compression by Planum Sphenoidale Meningioma.

PubMed

Di Somma, Alberto; Kaen, Ariel Matias; Cárdenas Ruiz-Valdepeñas, Eugenio; Cavallo, Luigi Maria

2018-05-01

In this study we report an uncommon endoscopic endonasal image of an atrophic optic nerve as seen after surgical removal of a suprasellar meningioma. The peculiarity of this case is the long-lasting underestimated ocular symptomatology of the patient who reported a 15-year history of impairment of vision on her left eye. A 51-year-old woman was admitted to our hospital complaining of a 15-year history of impairment of vision on her left eye. After making serendipitously the diagnosis of a suprasellar mass, we performed endoscopic endonasal surgery. The tumor was reached from below and removed safely, without manipulation of the optic pathways. At the end of tumor removal, the impressive left optic nerve atrophy due to enduring local tumor compression was visualized. To the best of our knowledge, no endoscopic endonasal image with such features has been provided in the pertinent literature. Possibly, this contribution will help identify damaged optic nerves during endoscopic endonasal surgery. Copyright © 2018 Elsevier Inc. All rights reserved.

Computer-aided decision support systems for endoscopy in the gastrointestinal tract: a review.

PubMed

Liedlgruber, Michael; Uhl, Andreas

2011-01-01

Today, medical endoscopy is a widely used procedure to inspect the inner cavities of the human body. The advent of endoscopic imaging techniques-allowing the acquisition of images or videos-created the possibility for the development of the whole new branch of computer-aided decision support systems. Such systems aim at helping physicians to identify possibly malignant abnormalities more accurately. At the beginning of this paper, we give a brief introduction to the history of endoscopy, followed by introducing the main types of endoscopes which emerged so far (flexible endoscope, wireless capsule endoscope, and confocal laser endomicroscope). We then give a brief introduction to computer-aided decision support systems specifically targeted at endoscopy in the gastrointestinal tract. Then we present general facts and figures concerning computer-aided decision support systems and summarize work specifically targeted at computer-aided decision support in the gastrointestinal tract. This summary is followed by a discussion of some common issues concerning the approaches reviewed and suggestions of possible ways to resolve them.

Automated working distance adjustment for a handheld OCT-Laryngoscope

NASA Astrophysics Data System (ADS)

Donner, Sabine; Bleeker, Sebastian; Ripken, Tammo; Krueger, Alexander

2014-03-01

Optical coherence tomography (OCT) is an imaging technique which enables diagnosis of vocal cord tissue structure by non-contact optical biopsies rather than invasive tissue biopsies. For diagnosis on awake patients OCT was adapted to a rigid indirect laryngoscope. The working distance must match the probe-sample distance, which varies from patient to patient. Therefore the endoscopic OCT sample arm has a variable working distance of 40 mm to 80 mm. The current axial position is identified by automated working distance adjustments based on image processing. The OCT reference plane and the focal plane of the sample arm are moved according to position errors. Repeated position adjustment during the whole diagnostic procedure keeps the tissue sample at the optimal axial position. The auto focus identifies and adjusts the working distance within the range of 50 mm within a maximum time of 2.7 s. Continuous image stabilisation reduces axial sample movement within the sampling depth for handheld OCT scanning. Rapid autofocus reduces the duration of the diagnostic procedure and axial position stabilisation eases the use of the OCT laryngoscope. Therefore this work is an important step towards the integration of OCT into indirect laryngoscopes.

Endoscopic surgical management of sinonasal inverted papilloma extending to frontal sinuses.

PubMed

Takahashi, Yukiko; Shoji, Fumi; Katori, Yukio; Hidaka, Hiroshi; Noguchi, Naoya; Abe, Yasuhiro; Kakuta, Risako Kakuta; Suzuki, Takahiro; Suzuki, Yusuke; Ohta, Nobuo; Kakehata, Seiji; Okamoto, Yoshitaka

2016-11-10

Sinonasal inverted papilloma has been traditionally managed with external surgical approaches. Advances in imaging guidance systems, surgical instrumentation, and intraoperative multi-visualization have led to a gradual shift from external approaches to endoscopic surgery. However, for anatomical and technical reasons, endoscopic surgery of sinonasal inverted papilloma extending to the frontal sinuses is still challenging. Here, we present our experience in endoscopic surgical management of sinonasal inverted papilloma extending to one or both frontal sinuses. We present 10 cases of sinonasal inverted papilloma extending to the frontal sinuses and successfully removed by endoscopic median drainage (Draf III procedure) under endoscopic guidance without any additional external approach. The whole cavity of the frontal sinuses was easily inspected at the end of the surgical procedure. No early or late complications were observed. No recurrence was identified after an average follow-up period of 39.5 months. Use of an endoscopic median drainage approach to manage sinonasal inverted papilloma extending to one or both frontal sinuses is feasible and seems effective.

Minimally invasive photopolymerization in intervertebral disc tissue cavities

NASA Astrophysics Data System (ADS)

Schmocker, Andreas M.; Khoushabi, Azadeh; Gantenbein-Ritter, Benjamin; Chan, Samantha; Bonél, Harald Marcel; Bourban, Pierre-Etienne; Mânson, Jan Anders; Schizas, Constantin; Pioletti, Dominique; Moser, Christophe

2014-03-01

Photopolymerized hydrogels are commonly used for a broad range of biomedical applications. As long as the polymer volume is accessible, gels can easily be hardened using light illumination. However, in clinics, especially for minimally invasive surgery, it becomes highly challenging to control photopolymerization. The ratios between polymerizationvolume and radiating-surface-area are several orders of magnitude higher than for ex-vivo settings. Also tissue scattering occurs and influences the reaction. We developed a Monte Carlo model for photopolymerization, which takes into account the solid/liquid phase changes, moving solid/liquid-boundaries and refraction on these boundaries as well as tissue scattering in arbitrarily designable tissue cavities. The model provides a tool to tailor both the light probe and the scattering/absorption properties of the photopolymer for applications such as medical implants or tissue replacements. Based on the simulations, we have previously shown that by adding scattering additives to the liquid monomer, the photopolymerized volume was considerably increased. In this study, we have used bovine intervertebral disc cavities, as a model for spinal degeneration, to study photopolymerization in-vitro. The cavity is created by enzyme digestion. Using a custom designed probe, hydrogels were injected and photopolymerized. Magnetic resonance imaging (MRI) and visual inspection tools were employed to investigate the successful photopolymerization outcomes. The results provide insights for the development of novel endoscopic light-scattering polymerization probes paving the way for a new generation of implantable hydrogels.

3D surface reconstruction for laparoscopic computer-assisted interventions: comparison of state-of-the-art methods

NASA Astrophysics Data System (ADS)

Groch, A.; Seitel, A.; Hempel, S.; Speidel, S.; Engelbrecht, R.; Penne, J.; Höller, K.; Röhl, S.; Yung, K.; Bodenstedt, S.; Pflaum, F.; dos Santos, T. R.; Mersmann, S.; Meinzer, H.-P.; Hornegger, J.; Maier-Hein, L.

2011-03-01

One of the main challenges related to computer-assisted laparoscopic surgery is the accurate registration of pre-operative planning images with patient's anatomy. One popular approach for achieving this involves intraoperative 3D reconstruction of the target organ's surface with methods based on multiple view geometry. The latter, however, require robust and fast algorithms for establishing correspondences between multiple images of the same scene. Recently, the first endoscope based on Time-of-Flight (ToF) camera technique was introduced. It generates dense range images with high update rates by continuously measuring the run-time of intensity modulated light. While this approach yielded promising results in initial experiments, the endoscopic ToF camera has not yet been evaluated in the context of related work. The aim of this paper was therefore to compare its performance with different state-of-the-art surface reconstruction methods on identical objects. For this purpose, surface data from a set of porcine organs as well as organ phantoms was acquired with four different cameras: a novel Time-of-Flight (ToF) endoscope, a standard ToF camera, a stereoscope, and a High Definition Television (HDTV) endoscope. The resulting reconstructed partial organ surfaces were then compared to corresponding ground truth shapes extracted from computed tomography (CT) data using a set of local and global distance metrics. The evaluation suggests that the ToF technique has high potential as means for intraoperative endoscopic surface registration.

The reliability of endoscopic examination in assessment of arytenoid cartilage movement in horses. Part II. Influence of side of examination, reexamination, and sedation.

PubMed

Ducharme, N G; Hackett, R P; Fubini, S L; Erb, H N

1991-01-01

Twenty Thoroughbred and Standardbred horses underwent endoscopic evaluation of arytenoid cartilage movement twice within 1 week. Each time, a flexible endoscope was passed without sedation through the right nostril and the left nostril, and through the right nostril 5 minutes after administration of xylazine hydrochloride (0.55 mg/kg or 1.1 mg/kg intravenously). Laryngeal cartilage movement was videorecorded. All videotaped images were reviewed by three veterinarians and subjectively placed in one of four grades. The intraobserver agreement rate varied from 52.6% for examination under sedation with 1.1 mg/kg of xylazine to 89.5% for unsedated reexamination through the left nostril. The effect of the various observations on median laryngeal grade was calculated. Examination under xylazine hydrochloride at either dosage yielded a change in median laryngeal grade from the unsedated examination in 45% of the evaluations. Reevaluation through the right or left nostril resulted in a different median laryngeal grade in 21% and 5% of the examinations, respectively. Objective measurements of the rima glottidis obtained by computer-assisted morphometric analysis of the recorded laryngeal images allowed laryngeal images to be dichotomized regardless of the condition of endoscopic examination. Endoscopic evaluation of laryngeal cartilage movement is subjective and is influenced by sedation with xylazine, evaluation through the alternate nostril, and different day of examination. The most consistent evaluation was obtained during repeated examination through the left nostril.

Capsule Endoscope Aspiration after Repeated Attempts for Ingesting a Patency Capsule

PubMed Central

Mannami, Tomohiko; Ikeda, Genyo; Seno, Satoru; Sonobe, Hiroshi; Fujiwara, Nobukiyo; Komoda, Minori; Edahiro, Satoru; Ohtawa, Yasuyuki; Fujimoto, Yoshimi; Sato, Naohiro; Kambara, Takeshi; Waku, Toshihiko

2015-01-01

Capsule endoscope aspiration into the respiratory tract is a rare complication of capsule endoscopy. Despite the potential seriousness of this complication, no accepted methods exist to accurately predict and therefore prevent it. We describe the case of an 85-year-old male who presented for evaluation of iron deficiency anemia. He complained of dysphagia while ingesting a patency capsule, with several attempts over a period of 5 min before he was successful. Five days later, he underwent capsule endoscopy, where he experienced similar symptoms in swallowing the capsule. The rest of the examination proceeded uneventfully. On reviewing the captured images, the capsule endoscope was revealed to be aspirated, remaining in the respiratory tract for approximately 220 s before images of the esophagus and stomach appeared. To our knowledge, this is the first documented case of a patient who experienced capsule endoscope aspiration after ingestion of a patency capsule. This case suggests that repeated attempts required for ingesting the patency capsule can predict capsule endoscope aspiration. We presume that paying sufficient attention to the symptoms of a patient who ingests a patency capsule could help us prevent serious complications such as aspiration of the capsule endoscope. In addition, this experience implies the potential risk for ingesting the patency capsule. We must be aware that the patency capsule could also be aspirated and there may be more unrecognized aspiration cases. PMID:26600772

Capsule Endoscope Aspiration after Repeated Attempts for Ingesting a Patency Capsule.

PubMed

Mannami, Tomohiko; Ikeda, Genyo; Seno, Satoru; Sonobe, Hiroshi; Fujiwara, Nobukiyo; Komoda, Minori; Edahiro, Satoru; Ohtawa, Yasuyuki; Fujimoto, Yoshimi; Sato, Naohiro; Kambara, Takeshi; Waku, Toshihiko

2015-01-01

Capsule endoscope aspiration into the respiratory tract is a rare complication of capsule endoscopy. Despite the potential seriousness of this complication, no accepted methods exist to accurately predict and therefore prevent it. We describe the case of an 85-year-old male who presented for evaluation of iron deficiency anemia. He complained of dysphagia while ingesting a patency capsule, with several attempts over a period of 5 min before he was successful. Five days later, he underwent capsule endoscopy, where he experienced similar symptoms in swallowing the capsule. The rest of the examination proceeded uneventfully. On reviewing the captured images, the capsule endoscope was revealed to be aspirated, remaining in the respiratory tract for approximately 220 s before images of the esophagus and stomach appeared. To our knowledge, this is the first documented case of a patient who experienced capsule endoscope aspiration after ingestion of a patency capsule. This case suggests that repeated attempts required for ingesting the patency capsule can predict capsule endoscope aspiration. We presume that paying sufficient attention to the symptoms of a patient who ingests a patency capsule could help us prevent serious complications such as aspiration of the capsule endoscope. In addition, this experience implies the potential risk for ingesting the patency capsule. We must be aware that the patency capsule could also be aspirated and there may be more unrecognized aspiration cases.

Ultrasound-assisted endoscopic partial plantar fascia release.

PubMed

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.

Ultrasound-Assisted Endoscopic Partial Plantar Fascia Release

PubMed Central

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. PMID:24265989

Biplane reconstruction and visualization of virtual endoscopic and fluoroscopic views for interventional device navigation

NASA Astrophysics Data System (ADS)

Wagner, Martin G.; Strother, Charles M.; Schafer, Sebastian; Mistretta, Charles A.

2016-03-01

Biplane fluoroscopic imaging is an important tool for minimally invasive procedures for the treatment of cerebrovascular diseases. However, finding a good working angle for the C-arms of the angiography system as well as navigating based on the 2D projection images can be a difficult task. The purpose of this work is to propose a novel 4D reconstruction algorithm for interventional devices from biplane fluoroscopy images and to propose new techniques for a better visualization of the results. The proposed reconstruction methods binarizes the fluoroscopic images using a dedicated noise reduction algorithm for curvilinear structures and a global thresholding approach. A topology preserving thinning algorithm is then applied and a path search algorithm minimizing the curvature of the device is used to extract the 2D device centerlines. Finally, the 3D device path is reconstructed using epipolar geometry. The point correspondences are determined by a monotonic mapping function that minimizes the reconstruction error. The three dimensional reconstruction of the device path allows the rendering of virtual fluoroscopy images from arbitrary angles as well as 3D visualizations like virtual endoscopic views or glass pipe renderings, where the vessel wall is rendered with a semi-transparent material. This work also proposes a combination of different visualization techniques in order to increase the usability and spatial orientation for the user. A combination of synchronized endoscopic and glass pipe views is proposed, where the virtual endoscopic camera position is determined based on the device tip location as well as the previous camera position using a Kalman filter in order to create a smooth path. Additionally, vessel centerlines are displayed and the path to the target is highlighted. Finally, the virtual endoscopic camera position is also visualized in the glass pipe view to further improve the spatial orientation. The proposed techniques could considerably improve the workflow of minimally invasive procedures for the treatment of cerebrovascular diseases.

Chronic radiation proctopathy: A practical review of endoscopic treatment.

PubMed

Lenz, Luciano; Rohr, Rachel; Nakao, Frank; Libera, Ermelindo; Ferrari, Angelo

2016-02-27

Chronic radiation proctopathy (CRP) is a troublesome complication of pelvic radiotherapy. The most common presentation is rectal bleeding. CRP symptoms interfere with daily activities and decrease quality of life. Rectal bleeding management in patients with CRP represents a conundrum for practitioners. Medical therapy is ineffective in general and surgical approach has a high morbid-mortality. Endoscopy has a role in the diagnosis, staging and treatment of this disease. Currently available endoscopic modalities are formalin, potassium titanyl phosphate laser, neodymium:yttrium-aluminum-garnet laser, argon laser, bipolar electrocoagulation (BiCAP), heater probe, band ligation, cryotherapy, radiofrequency ablation and argon plasma coagulation (APC). Among these options, APC is the most promising.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, Gary F.; Smith, John

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.

Processing urinary endoscopes in a low-temperature steam and formaldehyde autoclave.

PubMed Central

Gibson, G L

1977-01-01

Methods of disinfection and sterilisation of urinary endoscopes are considered. A small mobile low-temperature steam and formaldehyde autoclave (Miniclave 80) is evaluated and shown to be satisfactory for this purpose as judged by a variety of relevant microbiological test pieces. Images PMID:557503

High speed, wide velocity dynamic range Doppler optical coherence tomography (Part III): in vivo endoscopic imaging of blood flow in the rat and human gastrointestinal tracts

NASA Astrophysics Data System (ADS)

Yang, Victor X. D.; Gordon, Maggie L.; Tang, Shou-Jiang; Marcon, Norman E.; Gardiner, Geoffrey; Qi, Bing; Bisland, Stuart; Seng-Yue, Emily; Lo, Stewart; Pekar, Julius; Wilson, Brian C.; Vitkin, I. Alex

2003-09-01

We previously described a fiber based Doppler optical coherence tomography system [1] capable of imaging embryo cardiac blood flow at 4~16 frames per second with wide velocity dynamic range [2]. Coupling this system to a linear scanning fiber optical catheter design that minimizes friction and vibrations, we report here the initial results of in vivo endoscopic Doppler optical coherence tomography (EDOCT) imaging in normal rat and human esophagus. Microvascular flow in blood vessels less than 100 µm diameter was detected using a combination of color-Doppler and velocity variance imaging modes, during clinical endoscopy using a mobile EDOCT system.

Optical transfection using an endoscope-like system.

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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

In vivo endoscopic Doppler optical coherence tomography imaging of mouse colon

NASA Astrophysics Data System (ADS)

Welge, Weston A.; Barton, Jennifer K.

2016-03-01

Colorectal cancer remains the second deadliest cancer in the United States, despite the high sensitivity and specificity of colonoscopy and sigmoidoscopy. While these standard imaging procedures can accurately detect medium and large polyps, some studies have shown miss rates up to 25% for polyps less than 5 mm in diameter. An imaging modality capable of detecting small lesions could potentially improve patient outcomes. Optical coherence tomography (OCT) has been shown to be a powerful imaging modality for adenoma detection in a mouse model of colorectal cancer. While previous work has focused on analyzing the structural OCT images based on thickening of the mucosa and changes in light attenuation in depth, imaging the microvasculature of the colon may enable earlier detection of polyps. The structure and function of vessels grown to support tumor growth are markedly different from healthy vessels. Doppler OCT is capable of imaging microvessels in vivo. We developed a method of processing raw fringe data from a commercial swept-source OCT system using a lab-built miniature endoscope to extract microvessels. This method can be used to measure vessel count and density and to measure flow velocities. This may improve early detection and aid in the development of new chemopreventive and chemotherapeutic drugs. We present, to the best of our knowledge, the first endoscopic Doppler OCT images of in vivo mouse colon.

Endoscopic OCT for imaging of uterine body and cervix pathologies

NASA Astrophysics Data System (ADS)

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

1998-04-01

First results of endoscopic applications of optical coherence tomography (OCT) in gynecology are presented. We have studied mucosa of uterus, uterine cervix and vagina in vivo. Images of healthy endometrium in different stages of menstrual cycle have been recorded. For uterine cervix not only OCT data of normal state but some kids of pathology have been analyzed. Capability of OCT to identify alterations of mucosa makes this method promising for early diagnosis of tumors and precise guiding of excisional biopsy.

Endoscopic optical coherence tomography for imaging the tympanic membrane

NASA Astrophysics Data System (ADS)

Burkhardt, Anke; Walther, Julia; Cimalla, Peter; Bornitz, Matthias; Koch, Edmund

2011-06-01

Optical coherence tomography (OCT) is an imaging modality that enables micrometer-scale contactless subsurface imaging of biological tissue. Endoscopy, as another imaging method, has the potential of imaging tubular organs and cavities and therefore has opened up several application areas not accessible before. The combination of OCT and endoscopy uses the advantages of both methods and consequently allows additional imaging of structures beneath surfaces inside cavities. Currently, visual investigations on the surface of the human tympanic membrane are possible but only with expert eyes. up to now, visual imaging of the outer ear up to the tympanic membrane can be carried out by an otoscope, an operating microscope or an endoscope. In contrast to these devices, endoscopy has the advantage of imaging the whole tympanic membrane with one view. The intention of this research is the development of an endoscopic optical coherence tomography (EOCT) device for imaging the tympanic membrane depth-resolved and structures behind it. Detection of fluids in the middle ear, which function as an indicator for otitis media, could help to avoid the application of antibiotics. It is possible to detect a congeries of fluids with the otoscope but the ambition is to the early detection by OCT. The developed scanner head allows imaging in working distances in the range from zero up to 5 mm with a field of view of 2 mm. In the next step, the scanner head should be improved to increase the working distance and the field of view.

2D-3D registration using gradient-based MI for image guided surgery systems

NASA Astrophysics Data System (ADS)

Yim, Yeny; Chen, Xuanyi; Wakid, Mike; Bielamowicz, Steve; Hahn, James

2011-03-01

Registration of preoperative CT data to intra-operative video images is necessary not only to compare the outcome of the vocal fold after surgery with the preplanned shape but also to provide the image guidance for fusion of all imaging modalities. We propose a 2D-3D registration method using gradient-based mutual information. The 3D CT scan is aligned to 2D endoscopic images by finding the corresponding viewpoint between the real camera for endoscopic images and the virtual camera for CT scans. Even though mutual information has been successfully used to register different imaging modalities, it is difficult to robustly register the CT rendered image to the endoscopic image due to varying light patterns and shape of the vocal fold. The proposed method calculates the mutual information in the gradient images as well as original images, assigning more weight to the high gradient regions. The proposed method can emphasize the effect of vocal fold and allow a robust matching regardless of the surface illumination. To find the viewpoint with maximum mutual information, a downhill simplex method is applied in a conditional multi-resolution scheme which leads to a less-sensitive result to local maxima. To validate the registration accuracy, we evaluated the sensitivity to initial viewpoint of preoperative CT. Experimental results showed that gradient-based mutual information provided robust matching not only for two identical images with different viewpoints but also for different images acquired before and after surgery. The results also showed that conditional multi-resolution scheme led to a more accurate registration than single-resolution.

2D and 3D visualization methods of endoscopic panoramic bladder images

NASA Astrophysics Data System (ADS)

Behrens, Alexander; Heisterklaus, Iris; Müller, Yannick; Stehle, Thomas; Gross, Sebastian; Aach, Til

2011-03-01

While several mosaicking algorithms have been developed to compose endoscopic images of the internal urinary bladder wall into panoramic images, the quantitative evaluation of these output images in terms of geometrical distortions have often not been discussed. However, the visualization of the distortion level is highly desired for an objective image-based medical diagnosis. Thus, we present in this paper a method to create quality maps from the characteristics of transformation parameters, which were applied to the endoscopic images during the registration process of the mosaicking algorithm. For a global first view impression, the quality maps are laid over the panoramic image and highlight image regions in pseudo-colors according to their local distortions. This illustration supports then surgeons to identify geometrically distorted structures easily in the panoramic image, which allow more objective medical interpretations of tumor tissue in shape and size. Aside from introducing quality maps in 2-D, we also discuss a visualization method to map panoramic images onto a 3-D spherical bladder model. Reference points are manually selected by the surgeon in the panoramic image and the 3-D model. Then the panoramic image is mapped by the Hammer-Aitoff equal-area projection onto the 3-D surface using texture mapping. Finally the textured bladder model can be freely moved in a virtual environment for inspection. Using a two-hemisphere bladder representation, references between panoramic image regions and their corresponding space coordinates within the bladder model are reconstructed. This additional spatial 3-D information thus assists the surgeon in navigation, documentation, as well as surgical planning.

An endoscopic diffuse optical tomographic method with high resolution based on the improved FOCUSS method

NASA Astrophysics Data System (ADS)

Qin, Zhuanping; Ma, Wenjuan; Ren, Shuyan; Geng, Liqing; Li, Jing; Yang, Ying; Qin, Yingmei

2017-02-01

Endoscopic DOT has the potential to apply to cancer-related imaging in tubular organs. Although the DOT has relatively large tissue penetration depth, the endoscopic DOT is limited by the narrow space of the internal tubular tissue, so as to the relatively small penetration depth. Because some adenocarcinomas including cervical adenocarcinoma are located in deep canal, it is necessary to improve the imaging resolution under the limited measurement condition. To improve the resolution, a new FOCUSS algorithm along with the image reconstruction algorithm based on the effective detection range (EDR) is developed. This algorithm is based on the region of interest (ROI) to reduce the dimensions of the matrix. The shrinking method cuts down the computation burden. To reduce the computational complexity, double conjugate gradient method is used in the matrix inversion. For a typical inner size and optical properties of the cervix-like tubular tissue, reconstructed images from the simulation data demonstrate that the proposed method achieves equivalent image quality to that obtained from the method based on EDR when the target is close the inner boundary of the model, and with higher spatial resolution and quantitative ratio when the targets are far from the inner boundary of the model. The quantitative ratio of reconstructed absorption and reduced scattering coefficient can be up to 70% and 80% under 5mm depth, respectively. Furthermore, the two close targets with different depths can be separated from each other. The proposed method will be useful to the development of endoscopic DOT technologies in tubular organs.

Automatic specular reflections removal for endoscopic images

NASA Astrophysics Data System (ADS)

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.

Automatic classification of minimally invasive instruments based on endoscopic image sequences

NASA Astrophysics Data System (ADS)

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.

Ultrahigh speed en face OCT capsule for endoscopic imaging

PubMed Central

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.

2015-01-01

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. PMID:25909001

Ultrahigh speed en face OCT capsule for endoscopic imaging.

PubMed

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.

Fluorescence endoscopic imaging study of anastomotic recurrence of Crohn's disease after right ileocolonic resection

NASA Astrophysics Data System (ADS)

Mordon, Serge R.; Maunoury, Vincent; Klein, Olivier; Colombel, Jean-Frederic

1995-12-01

Crohn's disease is an inflammatory bowel disease of unknown etiology. Vasculitis is hypothesized but it was never demonstrated in vivo. This study aimed to evaluate the vascular mucosa perfusion using fluorescence imaging in 13 patients who had previously undergone eileocolonic resection and who agreed to participate in a prospective endoscopic study of anastomotic recurrence. This anastomotic recurrence rate is known to be high (73% after 1 year follow-up) and is characterized by ulcerations. The fluorescence study was started with an I.V. bolus injection of sodium fluorescein. The pre-anastomotic mucosa was endoscopically examined with blue light that stimulates fluorescein fluorescence. Fluorescence emission was recorded with an ultra-high-sensitivity camera connected to the endoscope via an interference filter (520 - 560 nm). A uniform fluorescence was observed a few seconds after the injection and lasted for 15 min in healthy subjects. In case of recurrence, the centers of the ulcerations displayed a very low fluorescence indicating localized ischemia. In contrast, the rims of the ulcers revealed brighter fluorescent images than those of normal mucosa. The anastomotic ulcerations of Crohn's disease recurrence exhibit a high fluorescence intensity at their margins indicating an increased mucosal blood flow and/or enhanced transcapillary diffusion. These findings support the hypothesis of a primary vasculitis in Crohn's disease.

Quantitative Evaluation of Adult Subglottic Stenosis Using Intraoperative Long-range Optical Coherence Tomography

PubMed Central

Sharma, Giriraj K.; Loy, Anthony Chin; Su, Erica; Jing, Joe; Chen, Zhongping; Wong, Brian J-F.; Verma, Sunil

2016-01-01

Objectives To determine the feasibility of long-range optical coherence tomography (LR-OCT) as a tool to intraoperatively image and measure the subglottis and trachea during suspension microlaryngoscopy before and after endoscopic treatment of subglottic stenosis (SGS). Methods Long-range optical coherence tomography of the adult subglottis and trachea was performed during suspension microlaryngoscopy before and after endoscopic treatment for SGS. The anteroposterior and transverse diameters, cross-sectional area (CSA), distance from the vocal cords, and length of the SGS were measured using a MATLAB software. Pre-intervention and postintervention airway dimensions were compared. Three-dimensional volumetric airway reconstructions were generated using medical image processing software (MIMICS). Results Intraoperative LR-OCT imaging was performed in 3 patients undergoing endoscopic management of SGS. Statistically significant differences in mean anteroposterior diameter (P < .01), transverse diameter (P < .001), and CSA (P < .001) were noted between pre-intervention and postintervention data. Three-dimensional airway models were viewed in cross-sectional format and via virtual “fly through” bronchoscopy. Conclusions This is the first report of intraoperative LR-OCT of the subglottic and tracheal airway before and after surgical management of SGS in humans. Long-range optical coherence tomography offers a practical means to measure the dimensions of SGS and acquire objective data on the response to endoscopic treatment of SGS. PMID:27354215

Endoscopic fluorescence imaging for early assessment of anastomotic recurrence of Crohn's disease

NASA Astrophysics Data System (ADS)

Mordon, Serge R.; Maunoury, Vincent; Geboes, K.; Klein, Olivier; Desreumaux, P.; Debaert, A.; Colombel, Jean-Frederic

1999-02-01

Crohn's disease is an inflammatory bowel disease of unknown etiology. The mechanism of the initial mucosal alterations is still unclear: ulcerations overlying lymphoid follicles and/or vasculitis have been proposed as the early lesions. We have developed a new and original method combining endoscopy of fluorescence angiography for identifying the early pathological lesions, occurring in the neo-terminal ileum after right ileocolonic resection. The patient population consisted of 10 subjects enrolled in a prospective protocol of endoscopic follow-up at 3 and 12 months after surgery. Fluorescence imaging showed small spots giving a bright fluorescence distributed singly in mucosa which appeared normal in routine endoscopy. Histopathological examination demonstrated that the fluorescence of small spots originated from small, usually superficial, erosive lesions. In several cases, these erosive lesions occurred over lymphoid follicles. Endoscopic fluorescence imaging provides a suitable means of investigating the initial aspect of the Crohn's disease process in displaying some correlative findings between fluorescent aspects and early pathological mucosal alterations.

Comparative Evaluation of the Ostium After External and Nonendoscopic Endonasal Dacryocystorhinostomy Using Image Processing (Matlabs and Image J) Softwares.

PubMed

Ganguly, Anasua; Kaza, Hrishikesh; Kapoor, Aditya; Sheth, Jenil; Ali, Mohammad Hasnat; Tripathy, Devjyoti; Rath, Suryasnata

The purpose of this study was to compare the characteristics of the ostium after external dacryocystorhinostomy and nonendoscopic endonasal dacryocystorhinostomy (NEN-DCR). This cross-sectional study included patients who underwent a successful external dacryocystorhinostomy or NEN-DCR and had ≥1 month follow up. Pictures of the ostium were captured with a nasal endoscope (4 mm, 30°) after inserting a lacrimal probe premarked at 2 mm. Image analyses were performed using Image J and Contour softwares. Of the 113 patients included, external dacryocystorhinostomy group had 53 patients and NEN-DCR group had 60 patients. The mean age of patients in the NEN-DCR group (38 years) was significantly (p < 0.05) lower than the external dacryocystorhinostomy group (50 years). There was no statistically significant difference (2 sample t test, p > 0.05) in mean follow up (6 vs. 4 months), maximum diameter of ostium (8 vs. 7 mm), perpendicular drawn to it (4 vs. 4 mm), area of ostium (43 vs. 36 mm), and the minimum distance between common internal punctum and edge of the ostium (1 vs. 1 mm) between the external and NEN-DCR groups. Image processing softwares offer simple and objective method to measure the ostium. While ostia are comparable in size, their relative position differs with posteriorly placed ostia in external compared with inferior in NEN-DCR.

A wideband spiral antenna for ingestible capsule endoscope systems: experimental results in a human phantom and a pig.

PubMed

Lee, Sang Heun; Lee, Jaebok; Yoon, Young Joong; Park, Sangbok; Cheon, Changyul; Kim, Kihyun; Nam, Sangwook

2011-06-01

This paper presents the design of a wideband spiral antenna for ingestible capsule endoscope systems and a comparison between the experimental results in a human phantom and a pig under general anesthesia. As wireless capsule endoscope systems transmit real-time internal biological image data at a high resolution to external receivers and because they operate in the human body, a small wideband antenna is required. To incorporate these properties, a thick-arm spiral structure is applied to the designed antenna. To make practical and efficient use of antennas inside the human body, which is composed of a high dielectric and lossy material, the resonance characteristics and radiation patterns were evaluated through a measurement setup using a liquid human phantom. The total height of the designed antenna is 5 mm and the diameter is 10 mm. The fractional bandwidth of the fabricated antenna is about 21% with a voltage standing-wave ratio of less than 2, and it has an isotropic radiation pattern. These characteristics are suitable for wideband capsule endoscope systems. Moreover, the received power level was measured using the proposed antenna, a circular polarized receiver antenna, and a pig under general anesthesia. Finally, endoscopic capsule images in the stomach and large intestine were captured using an on-off keying transceiver system.

Incidence of macroscopically occult neoplasias in Barrett's esophagus: are random biopsies dispensable in the era of advanced endoscopic imaging?

PubMed

Pohl, Juergen; Pech, Oliver; May, Andrea; Manner, Hendrik; Fissler-Eckhoff, Annette; Ell, Christian

2010-11-01

The gold standard for endoscopic surveillance of Barrett's esophagus (BE) includes targeted biopsies (TBs) from abnormalities as well as stepwise four-quadrant biopsies (4QBs) for detection of invisible high-grade intraepithelial neoplasias (HGINs) or early carcinomas (ECs). In a large mixed BE population, we investigated the rate of HGINs/ECs that are macroscopically occult to enhanced visualization with high-resolution endoscopy plus acetic acid chromoendoscopy. From January 2007 to December 2009, 701 consecutive BE patients were enrolled in a prospective study at a tertiary referral center. Of these, 406 patients had a history of HGIN/EC (high-risk group) and 295 patients did not (low-risk group). In 701 patients, 459 TBs and 5,485 4QBs were obtained. Altogether, 92 patients with 132 lesions containing HGINs/ECs were detected. For the diagnosis of HGINs/ECs, patient-related sensitivity and specificity rates of endoscopic imaging with TBs were 96.7 and 66.5%, with a positive and negative predictive value of 30.4 and 99.3%, respectively. In the high-risk group, 4QBs identified three additional patients (3.3%) with macroscopically occult HGINs/ECs. In the low-risk group, no HGINs/ECs were identified with either biopsy approach. Advanced endoscopic imaging identifies the vast majority of BE patients with early neoplasias, and the additive effect of 4QB is minimal. Therefore, in low- and high-risk patients, limiting endoscopic surveillance to guided biopsies is justified in specialized high-volume centers with permanent quality control. However, we do not advocate abandoning 4QB outside this setting.

Endoscopy Assisted Oncoplastic Breast Surgery (EAOBS)

PubMed Central

Soybir, Gürsel; Fukuma, Eisuke

2015-01-01

Endoscopic oncoplastic breast surgery represents a minimal invasive approach with the aim of both removing cancer safely and also restoring the breast image. It has less noticeable scar, excellent cosmetic outcomes, high patient satisfaction rate and recently reported relatively long term safety. Operative techniques for both endoscopic breast conserving surgery and endoscopic nipple/areola/skin sparing mastectomy have been described in detail. Two different working planes in which one of them is subcutaneous and the other one is sub-mammary planes are being used during the surgery. Surgical techniqe needs some instruments such as endoscopic retractor, light guided specific mammary retractor, wound protector and bipolar scissor. Endoscopic breast retractors provide magnified visualization and extensive posterior dissection facility. Tunneling method and hydrodissection simplify the technique in the subcutaneous field. Oncoplastic reconstruction techniques are also applied after the tumor resection by endoscopic method. Complication rates of endoscopic breast surgery are similar to open breast surgery rates. Quite succesful local recurrence, distant metastasis and overall survival rates have been declared. However it looks reasonable to wait for the results with longer follow-up before having a judgement about oncologic efficiency and safety of the endoscopic breast cancer surgery. PMID:28331692

Quantitative ENT endoscopy: the future in the new millennium

NASA Astrophysics Data System (ADS)

Mueller, Andreas; Schubert, Mario

1999-06-01

In Otorhinolaryngology the endoscopic appraisal of luminal dimensions of the nose, the throat, the larynx and the trachea is a daily problem. Those concerned with endoscopy know, that endoscopes distort dimensions of examined anatomical structures. To draw conclusions on luminal dimensions from the endoscopic pictures additional measuring devices are required. We developed a new method of measuring luminal dimensions in rigid or flexible endoscopy. For this a laser beam directed radially marks the anatomical lumen of interest in the videoendoscopic vision. The laser ring becomes deformed according to the form of the cavity explored. By keeping the distance defined between the laser ring and the top of the endoscope, the endoscopic video image can be measured. A piece of software developed by us calculates from the pictures the cross sectional area as well as the extension of benign or malign stenosis of the cavity explored. The result of the endoscopic measuring procedure can be visualized 3D on a PC-monitor. We are going to demonstrate the result of our clinical experience in different otorhinolaryngological diseases with the new endoscopic measuring kit in comparison to standard endoscopy. A further perspective is the endoscopic measuring kit in comparison to standard endoscopy. A further perspective is the endoscopic assisted manufacturing (EAM) of anatomical adapted stents, tubes and cannules.

Mitigating fluorescence spectral overlap in wide-field endoscopic imaging

PubMed Central

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

Advanced virtual endoscopy for endoscopic transsphenoidal pituitary surgery.

PubMed

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.

The universal serial bus endoscope: design and initial clinical experience.

PubMed

Hernandez-Zendejas, Gregorio; Dobke, Marek K; Guerrerosantos, Jose

2004-01-01

Endoscopic forehead lift is a well-established procedure in aesthetic plastic surgery. Many agree that currently available video-endoscopic equipment is bulky, multipieced and sometimes cumbersome in the operating theater. A novel system, the Universal Serial Bus Endoscope (USBE) was designed to simplify and reduce the number of necessary equipment pieces in the endoscopic setup. The USBE is attached by a single cable to a Universal Serial Bus (USB) port of a laptop computer. A built-in miniaturized cold light source provides illumination. A built-in digital camera chip enables procedure recording. The real-time images and movies obtained with USBE are displayed on the computer's screen and recorded on the laptop's hard disk drive. In this study, 25 patients underwent endoscopic browlift using the USBE system to test its clinical usefulness, all with good results and without complications or need for revision. The USBE was found to be reliable and easier to use than current video-endoscope equipment. The operative time needed to complete the procedure by the authors was reduced approximately 50%. The design and main technical characteristics of the USBE are presented.

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

PubMed

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.

Label-free in vivo in situ diagnostic imaging by cellular metabolism quantification with a flexible multiphoton endomicroscope (Conference Presentation)

NASA Astrophysics Data System (ADS)

Leclerc, Pierre; Hage, Charles-Henri; Fabert, Marc; Brevier, Julien; O'Connor, Rodney P.; Bardet-Coste, Sylvia M.; Habert, Rémi; Braud, Flavie; Kudlinski, Alexandre; Louradour, Frederic

2017-02-01

Multiphoton microscopy is a cutting edge imaging modality leading to increasing advances in biology and also in the clinical field. To use it at its full potential and at the very heart of clinical practice, there have been several developments of fiber-based multiphoton microendoscopes. The application for those probes is now limited by few major restrictions, such as the difficulty to collect autofluorescence signals from tissues and cells theses being inherently weak (e.g. the ones from intracellular NADH or FAD metabolites). This limitation reduces the usefulness of microendoscopy in general, effectively restraining it to morphological imaging modality requiring staining of the tissues. Our aim is to go beyond this limitation, showing for the first time label-free cellular metabolism monitoring, in vivo in situ in real time. The experimental setup is an upgrade of a recently published one (Ducourthial et.al, Scientific Reports, 2016) where femtosecond pulse fiber delivery is further optimized thank's to a new transmissive-GRISM-based pulse stretcher permitting high energy throughput and wide bandwidth. This device allows fast sequential operation with two different excitation wavelengths for efficient two-photon excited NADH and FAD autofluorescence endoscopic detection (i.e. 860 nm for FAD and 760 nm for NADH), enabling cellular optical redox ratio quantification at 8 frames/s. The obtained results on cell models in vitro and also on animal models in vivo (e.g. neurons of a living mouse) prove that we accurately assess the level of NADH and FAD at subcellular resolution through a 3-meters-long fiber with our miniaturized probe (O.D. =2.2 mm).

Quantitative and qualitative analysis of the working area obtained by endoscope and microscope in pterional and orbitozigomatic approach to the basilar artery bifurcation using computed tomography based frameless stereotaxy: A cadaver study

PubMed Central

Filipce, Venko; Ammirati, Mario

2015-01-01

Objective: Basilar aneurisms are one of the most complex and challenging pathologies for neurosurgeons to treat. Endoscopy is a recently rediscovered neurosurgical technique that could lend itself well to overcome some of the vascular visualization challenges associated with this pathology. The purpose of this study was to quantify and compare the basilar artery (BA) bifurcation (tip of the basilar) working area afforded by the microscope and the endoscope using different approaches and image guidance. Materials and Methods: We performed a total of 9 dissections, including pterional (PT) and orbitozygomatic (OZ) approaches bilaterally in five whole, fresh cadaver heads. We used computed tomography based image guidance for intraoperative navigation as well as for quantitative measurements. We estimated the working area of the tip of the basilar, using both a rigid endoscope and an operating microscope. Operability was qualitatively assessed by the senior authors. Results: In microscopic exposure, the OZ approach provided greater working area (160 ± 34.3 mm2) compared to the PT approach (129.8 ± 37.6 mm2) (P > 0.05). The working area in both PT and OZ approaches using 0° and 30° endoscopes was larger than the one available using the microscope alone (P < 0.05). In the PT approach, both 0° and 30° endoscopes provided a working area greater than a microscopic OZ approach (P < 0.05) and an area comparable to the OZ endoscopic approach (P > 0.05). Conclusion: Integration of endoscope and microscope in both PT and OZ approaches can provide significantly greater surgical exposure of the BA bifurcation compared to that afforded by the conventional approaches alone. PMID:25972933

Image stitching and image reconstruction of intestines captured using radial imaging capsule endoscope

NASA Astrophysics Data System (ADS)

Ou-Yang, Mang; Jeng, Wei-De; Wu, Yin-Yi; Dung, Lan-Rong; Wu, Hsien-Ming; Weng, Ping-Kuo; Huang, Ker-Jer; Chiu, Luan-Jiau

2012-05-01

This study investigates image processing using the radial imaging capsule endoscope (RICE) system. First, an experimental environment is established in which a simulated object has a shape that is similar to a cylinder, such that a triaxial platform can be used to push the RICE into the sample and capture radial images. Then four algorithms (mean absolute error, mean square error, Pearson correlation coefficient, and deformation processing) are used to stitch the images together. The Pearson correlation coefficient method is the most effective algorithm because it yields the highest peak signal-to-noise ratio, higher than 80.69 compared to the original image. Furthermore, a living animal experiment is carried out. Finally, the Pearson correlation coefficient method and vector deformation processing are used to stitch the images that were captured in the living animal experiment. This method is very attractive because unlike the other methods, in which two lenses are required to reconstruct the geometrical image, RICE uses only one lens and one mirror.

Using typical endoscopic features to diagnose esophageal squamous papilloma.

PubMed

Wong, Ming-Wun; Bair, Ming-Joug; Shih, Shou-Chuan; Chu, Cheng-Hsin; Wang, Horng-Yuan; Wang, Tsang-En; Chang, Chen-Wang; Chen, Ming-Jen

2016-02-21

To better understand some of the superficial tiny lesions that are recognized as squamous papilloma of the esophagus (SPE) and receive a different pathological diagnosis. All consecutive patients with esophageal polypoid lesions detected by routine endoscopy at our Endoscopy Centre between October 2009 and June 2014 were retrospectively analysed. We enrolled patients with SPE or other superficial lesions to investigate four key endoscopic appearances (whitish color, exophytic growth, wart-like shape, and surface vessels) and used narrow band imaging (NBI) to distinguish their differences. These series endoscopic images of each patient were retrospectively reviewed by three experienced endoscopists with no prior access to the images. All lesion specimens obtained by forceps biopsy were fixed in formalin and processed for pathological examination. The following data were collected from patient medical records: gender, age, indications for esophagogastroduodenoscopy, and endoscopic characteristics including lesion location, number, color, size, surface morphology, surrounding mucosa, and surface vessels under NBI. Clinicopathological features were also compared. During the study period, 41 esophageal polypoid lesions from 5698 endoscopic examinations were identified retrospectively. These included 24 patients with pathologically confirmed SPE, 11 patients with squamous hyperplasia, three patients with glycogenic acanthosis, two patients with ectopic sebaceous glands, and one patient with a xanthoma. In the χ (2) test, exophytic growth (P = 0.003), a wart-like shape (P < 0.001), and crossing surface vessels under NBI (P = 0.001) were more frequently observed in SPE than in other lesion types. By contrast, there was no significant difference regarding the appearance of a whitish color between SPE and other lesion types (P = 0.872). The most sensitive characteristic was wart-like projections (81.3%) and the most specific was exophytic growth (87.5%). Promising positive predictive values of 84.2%, 80.8%, and 82.6% were noted for exophytic growth, wart-like projections, and surface vessel crossing on NBI, respectively. The use of three key typical endoscopic appearances--exophytic growth, a wart-like shape, and vessel crossing on the lesion surface under NBI--has a promising positive predictive value of 88.2%. This diagnostic triad is useful for the endoscopic diagnosis of SPE.

Using typical endoscopic features to diagnose esophageal squamous papilloma

PubMed Central

Wong, Ming-Wun; Bair, Ming-Joug; Shih, Shou-Chuan; Chu, Cheng-Hsin; Wang, Horng-Yuan; Wang, Tsang-En; Chang, Chen-Wang; Chen, Ming-Jen

2016-01-01

AIM: To better understand some of the superficial tiny lesions that are recognized as squamous papilloma of the esophagus (SPE) and receive a different pathological diagnosis. METHODS: All consecutive patients with esophageal polypoid lesions detected by routine endoscopy at our Endoscopy Centre between October 2009 and June 2014 were retrospectively analysed. We enrolled patients with SPE or other superficial lesions to investigate four key endoscopic appearances (whitish color, exophytic growth, wart-like shape, and surface vessels) and used narrow band imaging (NBI) to distinguish their differences. These series endoscopic images of each patient were retrospectively reviewed by three experienced endoscopists with no prior access to the images. All lesion specimens obtained by forceps biopsy were fixed in formalin and processed for pathological examination. The following data were collected from patient medical records: gender, age, indications for esophagogastroduodenoscopy, and endoscopic characteristics including lesion location, number, color, size, surface morphology, surrounding mucosa, and surface vessels under NBI. Clinicopathological features were also compared. RESULTS: During the study period, 41 esophageal polypoid lesions from 5698 endoscopic examinations were identified retrospectively. These included 24 patients with pathologically confirmed SPE, 11 patients with squamous hyperplasia, three patients with glycogenic acanthosis, two patients with ectopic sebaceous glands, and one patient with a xanthoma. In the χ2 test, exophytic growth (P = 0.003), a wart-like shape (P < 0.001), and crossing surface vessels under NBI (P = 0.001) were more frequently observed in SPE than in other lesion types. By contrast, there was no significant difference regarding the appearance of a whitish color between SPE and other lesion types (P = 0.872). The most sensitive characteristic was wart-like projections (81.3%) and the most specific was exophytic growth (87.5%). Promising positive predictive values of 84.2%, 80.8%, and 82.6% were noted for exophytic growth, wart-like projections, and surface vessel crossing on NBI, respectively. CONCLUSION: The use of three key typical endoscopic appearances - exophytic growth, a wart-like shape, and vessel crossing on the lesion surface under NBI - has a promising positive predictive value of 88.2%. This diagnostic triad is useful for the endoscopic diagnosis of SPE. PMID:26900297

[New guidelines on chronic pancreatitis : interdisciplinary treatment strategies].

PubMed

Lerch, M M; Bachmann, K A; Izbicki, J R

2013-02-01

Chronic pancreatitis is a common disorder associated with significant morbidity and mortality. Interdisciplinary consensus guidelines have recently updated the definitions and diagnostic criteria for chronic pancreatitis and provide a critical assessment of therapeutic procedures. Diagnostic imaging relies on endoscopic ultrasound (EUS) as the most sensitive technique, whereas computed tomography (CT) and magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) remain a frequent preoperative requirement. Endoscopic retrograde cholangiopancreatography (ERCP) is now used mostly as a therapeutic procedure except for the differential diagnosis of autoimmune pancreatitis. Complications of chronic pancreatitis, such as pseudocysts, duct stricture and intractable pain can be treated with endoscopic interventions as well as open surgery. In the treatment of pseudocysts endoscopic drainage procedures now prevail while pain treatment has greater long-term effectiveness following surgical procedures. Currently, endocopic as well as surgical treatment of chronic pancreatitis require an ever increasing degree of technical and medical expertise and are provided increasingly more often by interdisciplinary centres. Surgical treatment is superior to interventional therapy regarding the outcome of pain control and duodenum-preserving pancreatic head resection is presently the surgical procedure of choice.

Molecular confocal laser endomicroscopy: a novel technique for in vivo cellular characterization of gastrointestinal lesions.

PubMed

Karstensen, John Gásdal; Klausen, Pia Helene; Saftoiu, Adrian; Vilmann, Peter

2014-06-28

While flexible endoscopy is essential for macroscopic evaluation, confocal laser endomicroscopy (CLE) has recently emerged as an endoscopic method enabling visualization at a cellular level. Two systems are currently available, one based on miniprobes that can be inserted via a conventional endoscope or via a needle guided by endoscopic ultrasound. The second system has a confocal microscope integrated into the distal part of an endoscope. By adding molecular probes like fluorescein conjugated antibodies or fluorescent peptides to this procedure (either topically or systemically administered during on-going endoscopy), a novel world of molecular evaluation opens up. The method of molecular CLE could potentially be used for estimating the expression of important receptors in carcinomas, subsequently resulting in immediate individualization of treatment regimens, but also for improving the diagnostic accuracy of endoscopic procedures by identifying otherwise invisible mucosal lesions. Furthermore, studies have shown that fluorescein labelled drugs can be used to estimate the affinity of the drug to a target organ, which probably can be correlated to the efficacy of the drug. However, several of the studies in this research field have been conducted in animal facilities or in vitro, while only a limited number of trials have actually been carried out in vivo. Therefore, safety issues still needs further evaluations. This review will present an overview of the implications and pitfalls, as well as future challenges of molecular CLE in gastrointestinal diseases.

Integrated biophotonics in endoscopic oncology

NASA Astrophysics Data System (ADS)

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 endoscopic diagnosis is likely to be impacted by a combination of biomarkers and technology, and 'endoscopic molecular imaging' should be defined as "visualization of molecular characteristics with endoscopy". These innovations will allow us not only to locate a tumor or dysplastic lesion but also to visualize its molecular characteristics (e.g., DNA mutations and polymorphisms, gene and/or protein expression), and the activity of specific molecules and biological processes that affect tumor behavior and/or its response to therapy. In the near future, these methods should be promising technologies that will play a central role in gastrointestinal oncology.

[Three-dimensional endoscopic endonasal study of skull base anatomy].

PubMed

Abarca-Olivas, Javier; Monjas-Cánovas, Irene; López-Álvarez, Beatriz; Lloret-García, Jaime; Sanchez-del Campo, Jose; Gras-Albert, Juan Ramon; Moreno-López, Pedro

2014-01-01

Training in dissection of the paranasal sinuses and the skull base is essential for anatomical understanding and correct surgical techniques. Three-dimensional (3D) visualisation of endoscopic skull base anatomy increases spatial orientation and allows depth perception. To show endoscopic skull base anatomy based on the 3D technique. We performed endoscopic dissection in cadaveric specimens fixed with formalin and with the Thiel technique, both prepared using intravascular injection of coloured material. Endonasal approaches were performed with conventional 2D endoscopes. Then we applied the 3D anaglyph technique to illustrate the pictures in 3D. The most important anatomical structures and landmarks of the sellar region under endonasal endoscopic vision are illustrated in 3D images. The skull base consists of complex bony and neurovascular structures. Experience with cadaver dissection is essential to understand complex anatomy and develop surgical skills. A 3D view constitutes a useful tool for understanding skull base anatomy. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Central endoscopy reads in inflammatory bowel disease clinical trials: The role of the imaging core lab

PubMed Central

Ahmad, Harris; Berzin, Tyler M.; Yu, Hui Jing; Huang, Christopher S.; Mishkin, Daniel S.

2014-01-01

Clinical trials in inflammatory bowel disease (IBD) are evolving at a rapid pace by employing central reading for endoscopic mucosal assessment in a field that was, historically, largely based on assessments by local physicians. This transition from local to central reading carries with it numerous technical, operational, and scientific challenges, many of which can be resolved by imaging core laboratories (ICLs), a concept that has a longer history in clinical trials in a number of diseases outside the realm of gastroenterology. For IBD trials, ICLs have the dual goals of providing objective, consistent assessments of endoscopic findings using central-reading paradigms whilst providing important expertise with regard to operational issues and regulatory expectations. This review focuses on current approaches to using ICLs for central endoscopic reading in IBD trials. PMID:24994835

Endoscopic spectral-domain polarization-sensitive optical coherence tomography system

NASA Astrophysics Data System (ADS)

Wang, Yi; Chen, Xiaodong; Hu, Zhiqiang; Li, Qiao; Yu, Daoyin

2008-02-01

In this paper, we introduced a fiber-based endoscopic Spectral-domain Polarization-sensitive OCT (SD-PS-OCT) experimental scheme for detecting the internal organ disease, which is based on low-coherence interferometer and two spectrometers. The SD-PS-OCT has the advantages of both Spectral-domain OCT (SD-OCT) and Polarization-sensitive OCT (PS-OCT). It is able to get the real-time image of reflectivity and birefringence distribution of tissue at the same time. The usage of SD-PS-OCT in endoscopic diagnosing system provides it the possibility to detect the internal organ disease. Since SD-PS-OCT can image the pathological changes of biological tissue below surface (1-3mm) with high resolution (1-15μm), it is able to help diagnosing early diseases of internal organs, which makes it a biomedical technology with bright future.

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

NASA Astrophysics Data System (ADS)

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.

Computer-Aided Diagnosis Based on Convolutional Neural Network System for Colorectal Polyp Classification: Preliminary Experience.

PubMed

Komeda, Yoriaki; Handa, Hisashi; Watanabe, Tomohiro; Nomura, Takanobu; Kitahashi, Misaki; Sakurai, Toshiharu; Okamoto, Ayana; Minami, Tomohiro; Kono, Masashi; Arizumi, Tadaaki; Takenaka, Mamoru; Hagiwara, Satoru; Matsui, Shigenaga; Nishida, Naoshi; Kashida, Hiroshi; Kudo, Masatoshi

2017-01-01

Computer-aided diagnosis (CAD) is becoming a next-generation tool for the diagnosis of human disease. CAD for colon polyps has been suggested as a particularly useful tool for trainee colonoscopists, as the use of a CAD system avoids the complications associated with endoscopic resections. In addition to conventional CAD, a convolutional neural network (CNN) system utilizing artificial intelligence (AI) has been developing rapidly over the past 5 years. We attempted to generate a unique CNN-CAD system with an AI function that studied endoscopic images extracted from movies obtained with colonoscopes used in routine examinations. Here, we report our preliminary results of this novel CNN-CAD system for the diagnosis of colon polyps. A total of 1,200 images from cases of colonoscopy performed between January 2010 and December 2016 at Kindai University Hospital were used. These images were extracted from the video of actual endoscopic examinations. Additional video images from 10 cases of unlearned processes were retrospectively assessed in a pilot study. They were simply diagnosed as either an adenomatous or nonadenomatous polyp. The number of images used by AI to learn to distinguish adenomatous from nonadenomatous was 1,200:600. These images were extracted from the videos of actual endoscopic examinations. The size of each image was adjusted to 256 × 256 pixels. A 10-hold cross-validation was carried out. The accuracy of the 10-hold cross-validation is 0.751, where the accuracy is the ratio of the number of correct answers over the number of all the answers produced by the CNN. The decisions by the CNN were correct in 7 of 10 cases. A CNN-CAD system using routine colonoscopy might be useful for the rapid diagnosis of colorectal polyp classification. Further prospective studies in an in vivo setting are required to confirm the effectiveness of a CNN-CAD system in routine colonoscopy. © 2017 S. Karger AG, Basel.

Optical Coherence Tomography of the Tympanic Membrane and Middle Ear: A Review.

PubMed

Tan, Hsern Ern Ivan; Santa Maria, Peter Luke; Wijesinghe, Philip; Francis Kennedy, Brendan; Allardyce, Benjamin James; Eikelboom, Robert Henry; Atlas, Marcus David; Dilley, Rodney James

2018-05-01

Objective To evaluate the recent developments in optical coherence tomography (OCT) for tympanic membrane (TM) and middle ear (ME) imaging and to identify what further development is required for the technology to be integrated into common clinical use. Data Sources PubMed, Embase, Google Scholar, Scopus, and Web of Science. Review Methods A comprehensive literature search was performed for English language articles published from January 1966 to January 2018 with the keywords "tympanic membrane or middle ear,"optical coherence tomography," and "imaging." Conclusion Conventional imaging techniques cannot adequately resolve the microscale features of TM and ME, sometimes necessitating diagnostic exploratory surgery in challenging otologic pathology. As a high-resolution noninvasive imaging technique, OCT offers promise as a diagnostic aid for otologic conditions, such as otitis media, cholesteatoma, and conductive hearing loss. Using OCT vibrometry to image the nanoscale vibrations of the TM and ME as they conduct acoustic waves may detect the location of ossicular chain dysfunction and differentiate between stapes fixation and incus-stapes discontinuity. The capacity of OCT to image depth and thickness at high resolution allows 3-dimensional volumetric reconstruction of the ME and has potential use for reconstructive tympanoplasty planning and the follow-up of ossicular prostheses. Implications for Practice To achieve common clinical use beyond these initial discoveries, future in vivo imaging devices must feature low-cost probe or endoscopic designs and faster imaging speeds and demonstrate superior diagnostic utility to computed tomography and magnetic resonance imaging. While such technology has been available for OCT, its translation requires focused development through a close collaboration between engineers and clinicians.

Monitored transoral endoscopic thyroidectomy via long monopolar stimulation probe.

PubMed

Dionigi, Gianlorenzo; Wu, Che-Wei; Tufano, Ralph P; Rizzo, Antonio Giacomo; Anuwong, Angkoon; Sun, Hui; Carcoforo, Paolo; Antonino, Cancellieri; Portinari, Mattia; Kim, Hoon Yub

2018-01-01

This video aimed to describe the role of intraoperative neuromonitoring (IONM) during transoral endoscopic thyroidectomy vestibular approach (TOETVA) with emphasis given to IONM technical and technological notes, the identification of recurrent laryngeal nerve (RLN). Standardized technique of IONM consist in identifying and monitoring both the vagus nerve and the RLNs before and after resection (V1, V2, R1, R2). According to this report, IONM during TOETVA is feasible and safe in providing identification and function of laryngeal nerves. IONM enable surgeons to feel more comfortable with their initial approach to TOETVA or extended indications. Larger series are needed for appropriated evaluation of IONM in reduction of the rates for RLN complications.

Monitored transoral endoscopic thyroidectomy via long monopolar stimulation probe

PubMed Central

Wu, Che-Wei; Tufano, Ralph P.; Rizzo, Antonio Giacomo; Anuwong, Angkoon; Sun, Hui; Carcoforo, Paolo; Antonino, Cancellieri; Portinari, Mattia; Kim, Hoon Yub

2018-01-01

This video aimed to describe the role of intraoperative neuromonitoring (IONM) during transoral endoscopic thyroidectomy vestibular approach (TOETVA) with emphasis given to IONM technical and technological notes, the identification of recurrent laryngeal nerve (RLN). Standardized technique of IONM consist in identifying and monitoring both the vagus nerve and the RLNs before and after resection (V1, V2, R1, R2). According to this report, IONM during TOETVA is feasible and safe in providing identification and function of laryngeal nerves. IONM enable surgeons to feel more comfortable with their initial approach to TOETVA or extended indications. Larger series are needed for appropriated evaluation of IONM in reduction of the rates for RLN complications. PMID:29445610

Laser-induced fluorescence for the detection of esophageal and skin cancer

NASA Astrophysics Data System (ADS)

Vo-Dinh, Tuan; Panjehpour, Masoud; Overholt, Bergein F.; Julius, Clark E.; Overholt, Suzanne; Phan, Mary N.

2003-07-01

Laser-induced fluorescence (LIF) is used for in-vivo cancer diagnosis of the esophagus and skin cancer. For esophageal measurements a fiberoptic probe inserted through an endoscope was used. Autofluorescence of normal and malignant tissues were measured directly on patient skin without requiring an endoscope. Measurement of the fluorescence signal from the tissue was performed using laser excitation at 410 nm. The methodology was applied to differentiate normal and malignant tumors of the esophagus and malignant skin lesions. The results of this LIF approach were compared with histopathology results of the biopsy samples and indicated excellent agreement in the classification of normal and malignant tumors for the samples investigated.

Endoscopic device for functional imaging of the retina

NASA Astrophysics Data System (ADS)

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.

The Value of Intraoperative Magnetic Resonance Imaging in Endoscopic and Microsurgical Transsphenoidal Pituitary Adenoma Resection.

PubMed

Pal'a, Andrej; Knoll, Andreas; Brand, Christine; Etzrodt-Walter, Gwendolin; Coburger, Jan; Wirtz, Christian Rainer; Hlaváč, Michal

2017-06-01

The routine use of intraoperative magnetic resonance imaging (iMRI) helps to achieve gross total resection in transsphenoidal pituitary surgery. We compared the added value of iMRI for extent of resection in endoscopic versus microsurgical transsphenoidal adenomectomy. A total of 96 patients with pituitary adenoma were included. Twenty-eight consecutive patients underwent endoscopic transsphenoidal tumor resection. For comparison, we used a historic cohort of 68 consecutive patients treated microsurgically. We evaluated the additional resection after conducting iMRI using intraoperative and late postoperative volumetric tumor analysis 3 months after surgery. Demographic data, clinical symptoms, and complications as well as pituitary function were evaluated. We found significantly fewer additional resections after conducting iMRI in the endoscopic group (P = 0.042). The difference was even more profound in Knosp grade 0-2 adenomas (P = 0.029). There was no significant difference in Knosp grade 3-4 adenomas (P = 0.520). The endoscopic approach was associated with smaller intraoperative tumor volume (P = 0.023). No significant difference was found between both techniques in postoperative tumor volume (P = 0.228). Satisfactory results of pituitary function were significantly more often associated with an endoscopic approach in the multiple regression analysis (P = 0.007; odds ratio, 17.614; confidence interval 95%, 2.164-143.396). With the endoscopic approach, significantly more tumor volume reduction was achieved before conducting iMRI, decreasing the need for further resection. This finding was even more pronounced in adenomas graded Knosp 0-2. In the case of extensive and invasive adenomas with infiltration of cavernous sinus and suprasellar or parasellar extension, additional tumor resection and increase in the extent of resection was achieved with iMRI in both groups. The endoscopic approach seems to result in better endocrine outcomes, especially in Knosp grade 0-2 pituitary adenomas. Copyright © 2017 Elsevier Inc. All rights reserved.

Simultaneous fingerprint and high-wavenumber fiber-optic Raman endoscopy for in vivo diagnosis of laryngeal cancer

NASA Astrophysics Data System (ADS)

Lin, Kan; Zheng, Wei; Wang, Jianfeng; Lim, Chwee Ming; Huang, Zhiwei

2016-02-01

We report a unique simultaneous fingerprint (FP) and high-wavenumber (HW) fiber-optic confocal Raman spectroscopy for in vivo diagnosis of laryngeal cancer in the head and neck under wide-field endoscopic imaging. The simultaneous FP and HW Raman endoscopy technique was performed on 21 patients and differentiated laryngeal carcinoma from normal tissues with both sensitivity and specificity of ~85%. This study shows the great potential of the FP/HW Raman endoscopic technique developed for in vivo diagnosis of laryngeal carcinoma during routine endoscopic examination.

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

PubMed

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 (P<.01) compared with 2D CT plates. With a share of more than 75% of surgery performed by residents, surgical time was reduced by 38±12.3min in CRS and 42±27.9 in sinonasal polyposis. The fourth-year residents reached 100% surgical competence in critical surgical milestones with 16 surgeries (CI 12-19). The systematic use of Osirix® for visualisation and treatment of 3D sinonasal images from DICOM data files, along with the surgical team's ability to manipulate them as virtual 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.

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

NASA Astrophysics Data System (ADS)

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.

Medical-grade Sterilizable Target for Fluid-immersed Fetoscope Optical Distortion Calibration.

PubMed

Nikitichev, Daniil I; Shakir, Dzhoshkun I; Chadebecq, François; Tella, Marcel; Deprest, Jan; Stoyanov, Danail; Ourselin, Sébastien; Vercauteren, Tom

2017-02-23

We have developed a calibration target for use with fluid-immersed endoscopes within the context of the GIFT-Surg (Guided Instrumentation for Fetal Therapy and Surgery) project. One of the aims of this project is to engineer novel, real-time image processing methods for intra-operative use in the treatment of congenital birth defects, such as spina bifida and the twin-to-twin transfusion syndrome. The developed target allows for the sterility-preserving optical distortion calibration of endoscopes within a few minutes. Good optical distortion calibration and compensation are important for mitigating undesirable effects like radial distortions, which not only hamper accurate imaging using existing endoscopic technology during fetal surgery, but also make acquired images less suitable for potentially very useful image computing applications, like real-time mosaicing. In this paper proposes a novel fabrication method to create an affordable, sterilizable calibration target suitable for use in a clinical setup. This method involves etching a calibration pattern by laser cutting a sandblasted stainless steel sheet. This target was validated using the camera calibration module provided by OpenCV, a state-of-the-art software library popular in the computer vision community.

Augmented Endoscopic Images Overlaying Shape Changes in Bone Cutting Procedures.

PubMed

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.

High-speed imaging with endoscopic optical coherence tomography using bending vibration of optical fiber

NASA Astrophysics Data System (ADS)

Isago, Ryoichi; Nakamura, Kentaro

2009-10-01

In this report, we propose an endoscopic scanner head for optical coherence tomography (OCT) using bending vibration of an optical fiber. The optical fiber is attached to the center of a cylindrical piezoelectric actuator with four outer electrodes, and the voltages with the phase shift of π/2 are applied to the electrodes to excite a circular vibration of the fiber end. The output light from the fiber end is collimated by a lens, and deflected by 90 degrees using a cone mirror. The collimated light is scanned along the circumference of the endoscope due to the vibration of the optical fiber end. We made a prototype scanner head of 7.0 mm in outer diameter, and demonstrated tomographic imaging of tubular objects. The circumferential scan is carried out at 1 kHz which is the frequency of the fiber vibration, while the radial (depth) scan is performed at 20 kHz by the wavelength sweep of the light source. Two-dimensional OCT images were obtained in a short measuring time of 5 ms (flame rate of 200 fps), and three-dimensional dynamic imaging were demonstrated.

Medical-grade Sterilizable Target for Fluid-immersed Fetoscope Optical Distortion Calibration

PubMed Central

Chadebecq, François; Tella, Marcel; Deprest, Jan; Stoyanov, Danail; Ourselin, Sébastien; Vercauteren, Tom

2017-01-01

We have developed a calibration target for use with fluid-immersed endoscopes within the context of the GIFT-Surg (Guided Instrumentation for Fetal Therapy and Surgery) project. One of the aims of this project is to engineer novel, real-time image processing methods for intra-operative use in the treatment of congenital birth defects, such as spina bifida and the twin-to-twin transfusion syndrome. The developed target allows for the sterility-preserving optical distortion calibration of endoscopes within a few minutes. Good optical distortion calibration and compensation are important for mitigating undesirable effects like radial distortions, which not only hamper accurate imaging using existing endoscopic technology during fetal surgery, but also make acquired images less suitable for potentially very useful image computing applications, like real-time mosaicing. In this paper proposes a novel fabrication method to create an affordable, sterilizable calibration target suitable for use in a clinical setup. This method involves etching a calibration pattern by laser cutting a sandblasted stainless steel sheet. This target was validated using the camera calibration module provided by OpenCV, a state-of-the-art software library popular in the computer vision community. PMID:28287588

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

PubMed

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

2008-05-01

Histopathological diagnosis of intraorbital tumours 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 tumours. 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 tumours and contributed to the reduction of surgical trauma during the procedure. The technique was particularly useful in small, medially located, retrobulbar tumours and in unclear situations when the structure of the lesion resembled surrounding intraorbital tissue.

A design of endoscopic imaging system for hyper long pipeline based on wheeled pipe robot

NASA Astrophysics Data System (ADS)

Zheng, Dongtian; Tan, Haishu; Zhou, Fuqiang

2017-03-01

An endoscopic imaging system of hyper long pipeline is designed to acquire the inner surface image in advance for the hyper long pipeline detects measurement. The system consists of structured light sensors, pipe robots and control system. The pipe robot is in the form of wheel structure, with the sensor which is at the front of the vehicle body. The control system is at the tail of the vehicle body in the form of upper and lower computer. The sensor can be translated and scanned in three steps: walking, lifting and scanning, then the inner surface image can be acquired at a plurality of positions and different angles. The results of imaging experiments show that the system's transmission distance is longer, the acquisition angle is more diverse and the result is more comprehensive than the traditional imaging system, which lays an important foundation for later inner surface vision measurement.

Correction of motion artifacts in OCT-AFI data collected in airways (Conference Presentation)

NASA Astrophysics Data System (ADS)

Abouei, Elham; Lane, Pierre M.; Pahlevaninezhad, Hamid; Lee, Anthony; Lam, Stephen; MacAulay, Calum E.

2016-03-01

Abstract: Optical coherence tomography (OCT) provides in vivo imaging with near-histologic resolution of tissue morphology. OCT has been successfully employed in clinical practice in non-pulmonary fields of medicine such as ophthalmology and cardiology. Studies suggest that OCT has the potential to be a powerful tool for the detection and localization of malignant and non-malignant pulmonary diseases. The combination of OCT with autofluorescence imaging (AFI) provides valuable information about the structural and metabolic state of tissues. Successful application of OCT or OCT-AFI to the field of pulmonary medicine requires overcoming several challenges. This work address those associated with motion: cardiac cycle, breathing and non-uniform rotation distortion (NURD) artifacts. Mechanically rotated endoscopic probes often suffer from image degradation due to NURD. In addition cardiac and breathing motion artifacts may be present in-vivo that are not seen ex-vivo. These motion artifacts can be problematic in OCT-AFI systems with slower acquisition rates and have been observed to generate identifiable prominent artifacts which make confident interpretation of observed structures (blood vessels, etc) difficult. Understanding and correcting motion artifact could improve the image quality and interpretation. In this work, the motion artifacts in pulmonary OCT-AFI data sets are estimated in both AFI and OCT images using a locally adaptive registration algorithm that can be used to correct/reduce such artifacts. Performance of the algorithm is evaluated on images of a NURD phantom and on in-vivo OCT-AFI datasets of peripheral lung airways.

Toward Intraoperative Image-Guided Transoral Robotic Surgery

PubMed Central

Liu, Wen P.; Reaugamornrat, Sureerat; Deguet, Anton; Sorger, Jonathan M.; Siewerdsen, Jeffrey H.; Richmon, Jeremy; Taylor, Russell H.

2014-01-01

This paper presents the development and evaluation of video augmentation on the stereoscopic da Vinci S system with intraoperative image guidance for base of tongue tumor resection in transoral robotic surgery (TORS). Proposed workflow for image-guided TORS begins by identifying and segmenting critical oropharyngeal structures (e.g., the tumor and adjacent arteries and nerves) from preoperative computed tomography (CT) and/or magnetic resonance (MR) imaging. These preoperative planned data can be deformably registered to the intraoperative endoscopic view using mobile C-arm cone-beam computed tomography (CBCT) [1, 2]. Augmentation of TORS endoscopic video defining surgical targets and critical structures has the potential to improve navigation, spatial orientation, and confidence in tumor resection. Experiments in animal specimens achieved statistically significant improvement in target localization error when comparing the proposed image guidance system to simulated current practice. PMID:25525474

Application of Convolutional Neural Networks in the Diagnosis of Helicobacter pylori Infection Based on Endoscopic Images.

PubMed

Shichijo, Satoki; Nomura, Shuhei; Aoyama, Kazuharu; Nishikawa, Yoshitaka; Miura, Motoi; Shinagawa, Takahide; Takiyama, Hirotoshi; Tanimoto, Tetsuya; Ishihara, Soichiro; Matsuo, Keigo; Tada, Tomohiro

2017-11-01

The role of artificial intelligence in the diagnosis of Helicobacter pylori gastritis based on endoscopic images has not been evaluated. We constructed a convolutional neural network (CNN), and evaluated its ability to diagnose H. pylori infection. A 22-layer, deep CNN was pre-trained and fine-tuned on a dataset of 32,208 images either positive or negative for H. pylori (first CNN). Another CNN was trained using images classified according to 8 anatomical locations (secondary CNN). A separate test data set (11,481 images from 397 patients) was evaluated by the CNN, and 23 endoscopists, independently. The sensitivity, specificity, accuracy, and diagnostic time were 81.9%, 83.4%, 83.1%, and 198s, respectively, for the first CNN, and 88.9%, 87.4%, 87.7%, and 194s, respectively, for the secondary CNN. These values for the 23 endoscopists were 79.0%, 83.2%, 82.4%, and 230±65min (85.2%, 89.3%, 88.6%, and 253±92min by 6 board-certified endoscopists), respectively. The secondary CNN had a significantly higher accuracy than endoscopists (by 5.3%; 95% CI, 0.3-10.2). H. pylori gastritis could be diagnosed based on endoscopic images using CNN with higher accuracy and in a considerably shorter time compared to manual diagnosis by endoscopists. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Stereo Imaging Miniature Endoscope with Single Imaging Chip and Conjugated Multi-Bandpass Filters

NASA Technical Reports Server (NTRS)

Shahinian, Hrayr Karnig (Inventor); Bae, Youngsam (Inventor); White, Victor E. (Inventor); Shcheglov, Kirill V. (Inventor); Manohara, Harish M. (Inventor); Kowalczyk, Robert S. (Inventor)

2018-01-01

A dual objective endoscope for insertion into a cavity of a body for providing a stereoscopic image of a region of interest inside of the body including an imaging device at the distal end for obtaining optical images of the region of interest (ROI), and processing the optical images for forming video signals for wired and/or wireless transmission and display of 3D images on a rendering device. The imaging device includes a focal plane detector array (FPA) for obtaining the optical images of the ROI, and processing circuits behind the FPA. The processing circuits convert the optical images into the video signals. The imaging device includes right and left pupil for receiving a right and left images through a right and left conjugated multi-band pass filters. Illuminators illuminate the ROI through a multi-band pass filter having three right and three left pass bands that are matched to the right and left conjugated multi-band pass filters. A full color image is collected after three or six sequential illuminations with the red, green and blue lights.

In vivo endoscopic Doppler optical coherence tomography imaging of the colon

PubMed Central

Welge, Weston A.; Barton, Jennifer K.

2017-01-01

Background and Objective Colorectal cancer remains the second deadliest cancer in the United States. Several screening methods exist, however detection of small polyps remains a challenge. Optical coherence tomography has been demonstrated to be capable of detecting lesions as small as 1 mm in the mouse colon, but detection is based on measuring a doubling of the mucosa thickness. The colon microvasculature may be an attractive biomarker of early tumor development because tumor vessels are characterized by irregular structure and dysfunction. Our goal was to develop an endoscopic method of detecting and segmenting colon vessels using Doppler optical coherence tomography to enable future studies for improving early detection and development of novel chemopreventive agents. Method We conducted in vivo colon imaging in an azoxymethane (AOM)-treated mouse model of colorectal cancer using a miniature endoscope and a swept-source OCT system at 1040 nm with a 16 kHz sweep rate. We applied the Kasai autocorrelation algorithm to laterally oversampled OCT B-scans to resolve vascular flow in the mucosa and submucosa. Vessels were segmented by applying a series of image processing steps: (1) intensity thresholding, (2) two-dimensional matched filtering, and (3) histogram segmentation. Results We observed differences in the vessels sizes and spatial distribution in a mature adenoma compared to surrounding undiseased tissue and compared the results with histology. We also imaged flow in four young mice (2 AOM-treated and 2 control) showing no significant differences, which is expected so early after carcinogen exposure. We also present flow images of adenoma in a living mouse and a euthanized mouse to demonstrate that no flow is detected after euthanasia. Conclusion We present, to the best of our knowledge, the first Doppler OCT images of in vivo mouse colon collected with a fiber-based endoscope. We also describe a fast and robust image processing method for segmenting vessels in the colon. These results suggest that Doppler OCT is a promising imaging modality for vascular imaging in the colon that requires no exogenous contrast agents. PMID:27546786

Comparing the Roles of EUS, ERCP and MRCP in Idiopathic Acute Recurrent Pancreatitis

PubMed Central

Safari, Mohammad Taghi; Miri, Mohammad Bager; Ebadi, Shahram; Shahrokh, Shabnam; Alizadeh, Amir Houshang Mohammad

2016-01-01

Acute recurrent pancreatitis (ARP) is defined as more than two attacks of acute pancreatitis with complete or almost complete resolution of symptoms and signs of pancreatitis between episodes. The initial evaluation fails to detect the cause of ARP in 10%–30% of patients, whose condition is classified as idiopathic ARP. Endoscopic ultrasound (EUS) has gained increasing attention as a useful imaging modality for the pancreas and the extrahepatic biliary tree. The close proximity of the pancreas to the digestive tract allows EUS to obtain detailed images of this organ. This review aims to record pancreaticobiliary endoscopic ultrasound (EUS) and other imaging modalities in the clinical management of patients with idiopathic ARP. PMID:27375362

Comparing the Roles of EUS, ERCP and MRCP in Idiopathic Acute Recurrent Pancreatitis.

PubMed

Safari, Mohammad Taghi; Miri, Mohammad Bager; Ebadi, Shahram; Shahrokh, Shabnam; Mohammad Alizadeh, Amir Houshang

2016-01-01

Acute recurrent pancreatitis (ARP) is defined as more than two attacks of acute pancreatitis with complete or almost complete resolution of symptoms and signs of pancreatitis between episodes. The initial evaluation fails to detect the cause of ARP in 10%-30% of patients, whose condition is classified as idiopathic ARP. Endoscopic ultrasound (EUS) has gained increasing attention as a useful imaging modality for the pancreas and the extrahepatic biliary tree. The close proximity of the pancreas to the digestive tract allows EUS to obtain detailed images of this organ. This review aims to record pancreaticobiliary endoscopic ultrasound (EUS) and other imaging modalities in the clinical management of patients with idiopathic ARP.

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

PubMed

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.

Image-enhanced endoscopy with I-scan technology for the evaluation of duodenal villous patterns.

PubMed

Cammarota, Giovanni; Ianiro, Gianluca; Sparano, Lucia; La Mura, Rossella; Ricci, Riccardo; Larocca, Luigi M; Landolfi, Raffaele; Gasbarrini, Antonio

2013-05-01

I-scan technology is the newly developed endoscopic tool that works in real time and utilizes a digital contrast method to enhance endoscopic image. We performed a feasibility study aimed to determine the diagnostic accuracy of i-scan technology for the evaluation of duodenal villous patterns, having histology as the reference standard. In this prospective, single center, open study, patients undergoing upper endoscopy for an histological evaluation of duodenal mucosa were enrolled. All patients underwent upper endoscopy using high resolution view in association with i-scan technology. During endoscopy, duodenal villous patterns were evaluated and classified as normal, partial villous atrophy, or marked villous atrophy. Results were then compared with histology. One hundred fifteen subjects were recruited in this study. The endoscopist was able to find marked villous atrophy of the duodenum in 12 subjects, partial villous atrophy in 25, and normal villi in the remaining 78 individuals. The i-scan system was demonstrated to have great accuracy (100 %) in the detection of marked villous atrophy patterns. I-scan technology showed quite lower accuracy in determining partial villous atrophy or normal villous patterns (respectively, 90 % for both items). Image-enhancing endoscopic technology allows a clear visualization of villous patterns in the duodenum. By switching from the standard to the i-scan view, it is possible to optimize the accuracy of endoscopy in recognizing villous alteration in subjects undergoing endoscopic evaluation.

Towards non-contact photo-acoustic endoscopy using speckle pattern analysis

NASA Astrophysics Data System (ADS)

Lengenfelder, Benjamin; Mehari, Fanuel; Tang, Yuqi; Klämpfl, Florian; Zalevsky, Zeev; Schmidt, Michael

2017-03-01

Photoacoustic Tomography combines the advantages of optical and acoustic imaging as it makes use of the high optical contrast of tissue and the high resolution of ultrasound. Furthermore, high penetration depths in tissue in the order of several centimeters can be achieved by the combination of these modalities. Extensive research is being done in the field of miniaturization of photoacoustic devices, as photoacoustic imaging could be of significant benefits for the physician during endoscopic interventions. All the existing miniature systems are based on contact transducers for signal detection that are placed at the distal end of an endoscopic device. This makes the manufacturing process difficult and impedance matching to the inspected surface a requirement. The requirement for contact limits the view of the physician during the intervention. Consequently, a fiber based non-contact optical sensing technique would be highly beneficial for the development of miniaturized photoacoustic endoscopic devices. This work demonstrates the feasibility of surface displacement detection using remote speckle-sensing using a high speed camera and an imaging fiber bundle that is used in commercially available video endoscopes. The feasibility of displacement sensing is demonstrated by analysis of phantom vibrations which are induced by loudspeaker membrane oscillations. Since the usability of the remote speckle-sensing for photo-acoustic signal detection was already demonstrated, the fiber bundle approach demonstrates the potential for non-contact photoacoustic detections during endoscopy.

Endoscopic management of benign biliary strictures.

PubMed

Rustagi, Tarun; Jamidar, Priya A

2015-01-01

Benign biliary strictures are a common indication for endoscopic retrograde cholangiopancreatography (ERCP). Endoscopic management has evolved over the last 2 decades as the current standard of care. The most common etiologies of strictures encountered are following surgery and those related to chronic pancreatitis. High-quality cross-sectional imaging provides a road map for endoscopic management. Currently, sequential placement of multiple plastic biliary stents represents the preferred approach. There is an increasing role for the treatment of these strictures using covered metal stents, but due to conflicting reports of efficacies as well as cost and complications, this approach should only be entertained following careful consideration. Optimal management of strictures is best achieved using a team approach with the surgeon and interventional radiologist playing an important role.

Whole-animal imaging of bacterial infection using endoscopic excitation of β-lactamase (BlaC)-specific fluorogenic probe

NASA Astrophysics Data System (ADS)

Nooshabadi, Fatemeh; Yang, Hee-Jeong; Cheng, Yunfeng; Xie, Hexin; Rao, Jianghong; Cirillo, Jeffrey D.; Maitland, Kristen C.

2016-03-01

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains one of the most frequent causes of death worldwide. The slow growth rate of Mtb limits progress toward understanding tuberculosis including diagnosis of infections and evaluating therapeutic efficacy. Development of near-infrared (NIR) β-lactamase (BlaC)-specific fluorogenic substrate has made a significant breakthrough in the whole-animal imaging to detect Mtb infection. The reporter enzyme fluorescence (REF) system using a BlaC-specific fluorogenic substrate has improved the detection sensitivity in whole-animal optical imaging down to ~104 colony forming units (CFU) of bacteria, about 100-fold improvement over recombinant strains. However, improvement of detection sensitivity is strongly needed for clinical diagnosis of early stage infection at greater tissue depth. In order to improve detection sensitivity, we have integrated a fiber-based microendoscpe into a whole-animal imaging system to transmit the excitation light from the fiber bundle to the fluorescent target directly and measure fluorescent level using BlaC-specific REF substrate in the mouse lung. REF substrate, CNIR800, was delivered via aerosol route to the pulmonary infected mice with M. bovis BCG strain at 24 hours post-infection and groups of mice were imaged at 1-4 hours post-administration of the substrate using the integrated imaging system. In this study we evaluated the kinetics of CNIR800 substrate using REF technology using the integrated imaging system. Integration of these technologies has great promise for improved detection sensitivity allowing pre-clinical imaging for evaluation of new therapeutic agents.

Intraventricular and skull base neuroendoscopy in 2012: a global survey of usage patterns and the role of intraoperative neuronavigation.

PubMed

Esposito, Felice; Di Rocco, Federico; Zada, Gabriel; Cinalli, Giuseppe; Schroeder, Henry W S; Mallucci, Conor; Cavallo, Luigi M; Decq, Philippe; Chiaramonte, Carmela; Cappabianca, Paolo

2013-12-01

During the past decade, endoscopic intraventricular and skull base operations have become widely used for a variety of evolving indications. A global survey of practicing endoscopic neurosurgeons was performed to characterize patterns of usage regarding endoscopy equipment, instrumentation, and the indications for using image-guided surgery systems (IGSs). An online survey consisting of 8 questions was completed by 235 neurosurgeons with endoscopic surgical experience. Responses were entered into a database and subsequently analyzed. The median number of operations performed per year by intraventricular and skull base endoscopic surgeons was 27 and 25, respectively. Data regarding endoscopic equipment brand, diameter, and length are presented. The most commonly reported indications for IGSs during intraventricular endoscopic surgery were tumor biopsy/resection, intraventricular cyst fenestration, septostomy/pellucidotomy, endoscopic third ventriculostomy, and aqueductal stent placement. Intraventricular surgeons reported using IGSs for all cases in 16.6% and never in 24.4%. Overall, endoscopic skull base surgeons reported using IGSs for all cases in 23.9% and never in 18.9%. The most commonly reported indications for IGSs during endoscopic skull base operations were complex sinus/skull base anatomy, extended approaches, and reoperation. Many variations and permutations for performing intraventricular and skull base endoscopic surgery exist worldwide. Much can be learned by studying the patterns and indications for using various types of equipment and operative adjuncts such as IGSs. Copyright © 2013 Elsevier Inc. All rights reserved.

Blood detection in wireless capsule endoscope images based on salient superpixels.

PubMed

Iakovidis, Dimitris K; Chatzis, Dimitris; Chrysanthopoulos, Panos; Koulaouzidis, Anastasios

2015-08-01

Wireless capsule endoscopy (WCE) enables screening of the gastrointestinal (GI) tract with a miniature, optical endoscope packed within a small swallowable capsule, wirelessly transmitting color images. In this paper we propose a novel method for automatic blood detection in contemporary WCE images. Blood is an alarming indication for the presence of pathologies requiring further treatment. The proposed method is based on a new definition of superpixel saliency. The saliency of superpixels is assessed upon their color, enabling the identification of image regions that are likely to contain blood. The blood patterns are recognized by their color features using a supervised learning machine. Experiments performed on a public dataset using automatically selected first-order statistical features from various color components indicate that the proposed method outperforms state-of-the-art methods.

Endoscopic Skipping of the Terminal Ileum in Pediatric Crohn Disease.

PubMed

Mansuri, Ishrat; Fletcher, Joel G; Bruining, David H; Kolbe, Amy B; Fidler, Jeff L; Samuel, Sunil; Tung, Jeanne

2017-06-01

Pediatric small-bowel (SB) Crohn disease (CD) may be missed if the terminal ileum (TI) appears normal at endoscopy and SB imaging is not performed. We sought to estimate the prevalence and clinical characteristics of pediatric patients with CD and endoscopic skipping of the TI-that is, pediatric patients with active SB or upper gut inflammation and an endoscopically normal TI. This retrospective study included pediatric patients with CD who underwent both CT enterography (CTE) or MR enterography (MRE) and ileocolonoscopy within a 30-day period between July 2004 and April 2014. The physician global assessment was used as the reference standard for SB CD activity. Radiologists reviewed the CTE and MRE studies for inflammatory parameters; severity, length, and multifocality of SB inflammation; and the presence of penetrating complications. Of 170 patients who underwent ileal intubation, the TI was macroscopically normal or showed nonspecific inflammation in 73 patients (43%). Nearly half (36/73, 49%) of the patients with normal or nonspecific findings at ileocolonoscopy had radiologically active disease with a median length of SB involvement of 20 cm (range, 1 to > 100 cm). Seventeen (47%) of these patients had multifocal SB involvement and five (14%) had penetrating complications. Overall, endoscopic TI skipping was present in 43 (59%) patients with normal or nonspecific ileocolonoscopic findings: 20 with histologic inflammation (17 with positive imaging findings), 14 with inflammation at imaging only, and nine with proximal disease (upper gut, jejunum, or proximal ileum). There were no significant differences in the clinical parameters of the patients with and those without endoscopic TI skipping. Ileocolonoscopy may miss SB CD in pediatric patients that is due to isolated histologic, intramural, or proximal inflammation. Enterography is complementary to ileocolonoscopy in the evaluation of pediatric CD.

LED-based endoscopic light source for spectral imaging

NASA Astrophysics Data System (ADS)

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

2016-03-01

Colorectal cancer is the United States 3rd leading cancer in death rates.1 The current screening for colorectal cancer is an endoscopic procedure using white light endoscopy (WLE). There are multiple new methods testing to replace WLE, for example narrow band imaging and autofluorescence imaging.2 However, these methods do not meet the need for a higher specificity or sensitivity. The goal for this project is to modify the presently used endoscope light source to house 16 narrow wavelength LEDs for spectral imaging in real time while increasing sensitivity and specificity. The process to do such was to take an Olympus CLK-4 light source, replace the light and electronics with 16 LEDs and new circuitry. This allows control of the power and intensity of the LEDs. This required a larger enclosure to house a bracket system for the solid light guide (lightpipe), three new circuit boards, a power source and National Instruments hardware/software for computer control. The results were a successfully designed retrofit with all the new features. The LED testing resulted in the ability to control each wavelength's intensity. The measured intensity over the voltage range will provide the information needed to couple the camera for imaging. Overall the project was successful; the modifications to the light source added the controllable LEDs. This brings the research one step closer to the main goal of spectral imaging for early detection of colorectal cancer. Future goals will be to connect the camera and test the imaging process.

Image-enhanced endoscopy for diagnosis of colorectal tumors in view of endoscopic treatment

PubMed Central

Yoshida, Naohisa; Yagi, Nobuaki; Yanagisawa, Akio; Naito, Yuji

2012-01-01

Recently, image-enhanced endoscopy (IEE) has been used to diagnose gastrointestinal tumors. This method is a change from conventional white-light (WL) endoscopy without dyeing solution, requiring only the push of a button. In IEE, there are many advantages in diagnosis of neoplastic tumors, evaluation of invasion depth for cancerous lesions, and detection of neoplastic lesions. In narrow band imaging (NBI) systems (Olympus Medical Co., Tokyo, Japan), optical filters that allow narrow-band light to pass at wavelengths of 415 and 540 nm are used. Mucosal surface blood vessels are seen most clearly at 415 nm, which is the wavelength that corresponds to the hemoglobin absorption band, while vessels in the deep layer of the mucosa can be detected at 540 nm. Thus, NBI also can detect pit-like structures named surface pattern. The flexible spectral imaging color enhancement (FICE) system (Fujifilm Medical Co., Tokyo, Japan) is also an IEE but different to NBI. FICE depends on the use of spectral-estimation technology to reconstruct images at different wavelengths based on WL images. FICE can enhance vascular and surface patterns. The autofluorescence imaging (AFI) video endoscope system (Olympus Medical Co., Tokyo, Japan) is a new illumination method that uses the difference in intensity of autofluorescence between the normal area and neoplastic lesions. AFI light comprises a blue light for emitting and a green light for hemoglobin absorption. The aim of this review is to highlight the efficacy of IEE for diagnosis of colorectal tumors for endoscopic treatment. PMID:23293724

Holographic high-resolution endoscopic image recording

NASA Astrophysics Data System (ADS)

Bjelkhagen, Hans I.

1991-03-01

Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help

A robust motion estimation system for minimal invasive laparoscopy

NASA Astrophysics Data System (ADS)

Marcinczak, Jan Marek; von Öhsen, Udo; Grigat, Rolf-Rainer

2012-02-01

Laparoscopy is a reliable imaging method to examine the liver. However, due to the limited field of view, a lot of experience is required from the surgeon to interpret the observed anatomy. Reconstruction of organ surfaces provide valuable additional information to the surgeon for a reliable diagnosis. Without an additional external tracking system the structure can be recovered from feature correspondences between different frames. In laparoscopic images blurred frames, specular reflections and inhomogeneous illumination make feature tracking a challenging task. We propose an ego-motion estimation system for minimal invasive laparoscopy that can cope with specular reflection, inhomogeneous illumination and blurred frames. To obtain robust feature correspondence, the approach combines SIFT and specular reflection segmentation with a multi-frame tracking scheme. The calibrated five-point algorithm is used with the MSAC robust estimator to compute the motion of the endoscope from multi-frame correspondence. The algorithm is evaluated using endoscopic videos of a phantom. The small incisions and the rigid endoscope limit the motion in minimal invasive laparoscopy. These limitations are considered in our evaluation and are used to analyze the accuracy of pose estimation that can be achieved by our approach. The endoscope is moved by a robotic system and the ground truth motion is recorded. The evaluation on typical endoscopic motion gives precise results and demonstrates the practicability of the proposed pose estimation system.

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

PubMed

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.

Miniature endoscopic optical coherence tomography for calculus detection.

PubMed

Kao, Meng-Chun; Lin, Chun-Li; Kung, Che-Yen; Huang, Yi-Fung; Kuo, Wen-Chuan

2015-08-20

The effective treatment of periodontitis involves the detection and removal of subgingival dental calculus. However, subgingival calculus is more difficult to detect than supragingival calculus because it is firmly attached to root surfaces within periodontal pockets. To achieve a smooth root surface, clinicians often remove excessive amounts of root structure because of decreased visibility. In addition, enamel pearl, a rare type of ectopic enamel formation on the root surface, can easily be confused with dental calculus in the subgingival environment. In this study, we developed a fiber-probe swept-source optical coherence tomography (SSOCT) technique and combined it with the quantitative measurement of an optical parameter [standard deviation (SD) of the optical coherence tomography (OCT) intensity] to differentiate subgingival calculus from sound enamel, including enamel pearl. Two-dimensional circumferential images were constructed by rotating the miniprobe (0.9 mm diameter) while acquiring image lines, and the adjacent lines in each rotation were stacked to generate a three-dimensional volume. In OCT images, compared to sound enamel and enamel pearls, dental calculus showed significant differences (P<0.001) in SD values. Finally, the receiver operating characteristic curve had a high capacity (area under the curve=0.934) for discriminating between healthy regions (including enamel pearl) and dental calculus.

Central endoscopy reads in inflammatory bowel disease clinical trials: The role of the imaging core lab.

PubMed

Ahmad, Harris; Berzin, Tyler M; Yu, Hui Jing; Huang, Christopher S; Mishkin, Daniel S

2014-08-01

Clinical trials in inflammatory bowel disease (IBD) are evolving at a rapid pace by employing central reading for endoscopic mucosal assessment in a field that was, historically, largely based on assessments by local physicians. This transition from local to central reading carries with it numerous technical, operational, and scientific challenges, many of which can be resolved by imaging core laboratories (ICLs), a concept that has a longer history in clinical trials in a number of diseases outside the realm of gastroenterology. For IBD trials, ICLs have the dual goals of providing objective, consistent assessments of endoscopic findings using central-reading paradigms whilst providing important expertise with regard to operational issues and regulatory expectations. This review focuses on current approaches to using ICLs for central endoscopic reading in IBD trials. © The Author(s) 2014. Published by Oxford University Press and the Digestive Science Publishing Co. Limited.

Diagnosis and management of pancreaticopleural fistula.

PubMed

Tay, Clifton Ming; Chang, Stephen Kin Yong

2013-04-01

Pancreaticopleural fistula is a rare diagnosis requiring a high index of clinical suspicion due to the predominant manifestation of thoracic symptoms. The current literature suggests that confirmation of elevated pleural fluid amylase is the most important diagnostic test. Magnetic resonance cholangiopancreatography is the recommended imaging modality to visualise the fistula, as it is superior to both computed tomography and endoscopic retrograde cholangiopancreatography (ERCP) in delineating the tract within the pancreatic region. It is also less invasive than ERCP. While a trial of medical regimen has traditionally been the first-line treatment, failure would result in higher rates of complications. Hence, it is suggested that management strategies be planned based on pancreatic ductal imaging, with patients having poor chances of spontaneous closure undergoing either endoscopic or surgical intervention. We also briefly describe a case of pancreaticopleural fistula in a patient who was treated using a modified Puestow procedure after failed endoscopic treatment.

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

PubMed

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.

Screening, management and surveillance for the sessile serrated adenomas/polyps.

PubMed

Fu, Xiangsheng; Qiu, Ye; Zhang, Yali

2014-01-01

The incidence and mortality rates from right-sided colorectal cancers (CRCs) have not decreased, compared with the significant reduction of CRCs in the left colon in recent years. It is likely that a significant proportion of right-sided CRCs evolve from undetected sessile serrated adenomas/polyps (SSA/Ps) in the primary colonoscopy. Increasing evidences suggest that SSA/Ps are high-risk lesions, with 15% of the SSA/P patients developing subsequent CRCs or adenomas with high-grade dysplasia. However, there are many issues in the screening, management and surveillance of SSA/Ps. Based on new evidences, this review addresses major issues in the diagnostic criteria for the serrated polyps of the colorectum, new endoscopic techniques (high-resolution magnifying endoscopy, narrow-band imaging, autofluorescence imaging, confocal laser endoscopy, and endocytoscopy) for the realtime identification of SSA/Ps, and the management of SSA/Ps by endoscopic mucosal resection, endoscopic sub-mucosal dissection or surgical resection in practice.

Photometric stereo endoscopy.

PubMed

Parot, Vicente; Lim, Daryl; González, Germán; Traverso, Giovanni; Nishioka, Norman S; Vakoc, Benjamin J; Durr, Nicholas J

2013-07-01

While color video endoscopy has enabled wide-field examination of the gastrointestinal tract, it often misses or incorrectly classifies lesions. Many of these missed lesions exhibit characteristic three-dimensional surface topographies. An endoscopic system that adds topographical measurements to conventional color imagery could therefore increase lesion detection and improve classification accuracy. We introduce photometric stereo endoscopy (PSE), a technique which allows high spatial frequency components of surface topography to be acquired simultaneously with conventional two-dimensional color imagery. We implement this technique in an endoscopic form factor and demonstrate that it can acquire the topography of small features with complex geometries and heterogeneous optical properties. PSE imaging of ex vivo human gastrointestinal tissue shows that surface topography measurements enable differentiation of abnormal shapes from surrounding normal tissue. Together, these results confirm that the topographical measurements can be obtained with relatively simple hardware in an endoscopic form factor, and suggest the potential of PSE to improve lesion detection and classification in gastrointestinal imaging.

A large-scan-angle piezoelectric MEMS optical scanner actuated by a Nb-doped PZT thin film

NASA Astrophysics Data System (ADS)

Naono, Takayuki; Fujii, Takamichi; Esashi, Masayoshi; Tanaka, Shuji

2014-01-01

Resonant 1D microelectromechanical systems (MEMS) optical scanners actuated by piezoelectric unimorph actuators with a Nb-doped lead zirconate titanate (PNZT) thin film were developed for endoscopic optical coherence tomography (OCT) application. The MEMS scanners were designed as the resonance frequency was less than 125 Hz to obtain enough pixels per frame in OCT images. The device size was within 3.4 mm × 2.5 mm, which is compact enough to be installed in a side-imaging probe with 4 mm inner diameter. The fabrication process started with a silicon-on-insulator wafer, followed by PNZT deposition by the Rf sputtering and Si bulk micromachining process. The fabricated MEMS scanners showed maximum optical scan angles of 146° at 90 Hz, 148° at 124 Hz, 162° at 180 Hz, and 152° at 394 Hz at resonance in atmospheric pressure. Such wide scan angles were obtained by a drive voltage below 1.3 Vpp, ensuring intrinsic safety in in vivo uses. The scanner with the unpoled PNZT film showed three times as large a scan angle as that with a poled PZT films. A swept-source OCT system was constructed using the fabricated MEMS scanner, and cross-sectional images of a fingertip with image widths of 4.6 and 2.3 mm were acquired. In addition, a PNZT-based angle sensor was studied for feedback operation.

Narrow band imaging versus autofluorescence imaging for head and neck squamous cell carcinoma detection: a prospective study.

PubMed

Ni, X-G; Zhang, Q-Q; Wang, G-Q

2016-11-01

This study aimed to compare the diagnostic effectiveness of narrow band imaging and autofluorescence imaging for malignant laryngopharyngeal tumours. Between May 2010 and October 2010, 50 consecutive patients with suspected laryngopharyngeal tumour underwent endoscopic laryngopharynx examination. The morphological characteristics of laryngopharyngeal lesions were analysed using high performance endoscopic systems equipped with narrow band imaging and autofluorescence imaging modes. The diagnostic effectiveness of white light image, narrow band imaging and autofluorescence imaging endoscopy for benign and malignant laryngopharyngeal lesions was evaluated. Under narrow band imaging endoscopy, the superficial microvessels of squamous cell carcinomas appeared as dark brown spots or twisted cords. Under autofluorescence imaging endoscopy, malignant lesions appeared as bright purple. The sensitivity of malignant lesion diagnosis was not significantly different between narrow band imaging and autofluorescence imaging modes, but was better than for white light image endoscopy (χ2 = 12.676, p = 0.002). The diagnostic specificity was significantly better in narrow band imaging mode than in both autofluorescence imaging and white light imaging mode (χ2 = 8.333, p = 0.016). Narrow band imaging endoscopy is the best option for the diagnosis and differential diagnosis of laryngopharyngeal tumours.

A blue optical filter for narrow-band imaging in endoscopic capsules

NASA Astrophysics Data System (ADS)

Silva, M. F.; Ghaderi, M.; Goncalves, L. M.; de Graaf, G.; Wolffenbuttel, R. F.; Correia, J. H.

2014-05-01

This paper presents the design, simulation, fabrication, and characterization of a thin-film Fabry-Perot resonator composed of titanium dioxide (TiO2) and silicon dioxide (SiO2) thin-films. The optical filter is developed to be integrated with a light emitting diode (LED) for enabling narrow-band imaging (NBI) in endoscopy. The NBI is a high resolution imaging technique that uses spectrally centered blue light (415 nm) and green light (540 nm) to illuminate the target tissue. The light at 415 nm enhances the imaging of superficial veins due to their hemoglobin absorption, while the light at 540 nm penetrates deeper into the mucosa, thus enhances the sub-epithelial vessels imaging. Typically the endoscopes and endoscopic capsules use white light for acquiring images of the gastrointestinal (GI) tract. However, implementing the NBI technique in endoscopic capsules enhances their capabilities for the clinical applications. A commercially available blue LED with a maximum peak intensity at 404 nm and Full Width Half Maximum (FWHM) of 20 nm is integrated with a narrow band blue filter as the NBI light source. The thin film simulations show a maximum spectral transmittance of 36 %, that is centered at 415 nm with FWHM of 13 nm for combined the blue LED and a Fabry Perot resonator system. A custom made deposition scheme was developed for the fabrication of the blue optical filter by RF sputtering. RF powered reactive sputtering at 200 W with the gas flows of argon and oxygen that are controlled for a 5:1 ratio gives the optimum optical conditions for TiO2 thin films. For SiO2 thin films, a non-reactive RF sputtering at 150 W with argon gas flow at 15 sccm results in the best optical performance. The TiO2 and SiO2 thin films were fully characterized by an ellipsometer in the wavelength range between 250 nm to 1600 nm. Finally, the optical performance of the blue optical filter is measured and presented.

Three-photon imaging of ovarian cancer

NASA Astrophysics Data System (ADS)

Barton, Jennifer K.; Amirsolaimani, Babak; Rice, Photini; Hatch, Kenneth; Kieu, Khanh

2016-02-01

Optical imaging methods have the potential to detect ovarian cancer at an early, curable stage. Optical imaging has the disadvantage that high resolution techniques require access to the tissue of interest, but miniature endoscopes that traverse the natural orifice of the reproductive tract, or access the ovaries and fallopian tubes through a small incision in the vagina wall, can provide a minimally-invasive solution. We have imaged both rodent and human ovaries and fallopian tubes with a variety of endoscope-compatible modalities. The recent development of fiber-coupled femtosecond lasers will enable endoscopic multiphoton microscopy (MPM). We demonstrated two- and three-photon excited fluorescence (2PEF, 3PEF), and second- and third-harmonic generation microscopy (SHG, THG) in human ovarian and fallopian tube tissue. A study was undertaken to understand the mechanisms of contrast in these images. Six patients (normal, cystadenoma, and ovarian adenocarcinoma) provided ovarian and fallopian tube biopsies. The tissue was imaged with three-dimensional optical coherence tomography, multiphoton microscopy, and frozen for histological sectioning. Tissue sections were stained with hematoxylin and eosin, Masson's trichrome, and Sudan black. Approximately 1 μm resolution images were obtained with an excitation source at 1550 nm. 2PEF signal was absent. SHG signal was mainly from collagen. 3PEF and THG signal came from a variety of sources, including a strong signal from fatty connective tissue and red blood cells. Adenocarcinoma was characterized by loss of SHG signal, whereas cystic abnormalities showed strong SHG. There was limited overlap of two- and three- photon signals, suggesting that three-photon imaging can provide additional information for early diagnosis of ovarian cancer.

SECM half-inch tethered endoscopic capsule (HITEC) for esophageal imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kang, DongKyun; Kim, Minkyu; Carruth, Robert W.; Lu, Weina; Wu, Tao; Alali, Sanaz; Do, Dukho; Soomro, Amna R.; Grant, Catriona N.; Tiernan, Aubrey R.; Rosenberg, Mireille; Nishioka, Norman S.; Tearney, Guillermo J.

2016-03-01

Spectrally encoded confocal microscopy (SECM) is a high-speed confocal endomicroscopy technology that can image extremely large regions of human tissue at cellular resolution within a short imaging time. Previously, we have developed a 7-mm-diameter SECM endoscopic capsule and successfully demonstrated imaging of human esophagus in vivo. Even though we were able to successfully capture images with the previous capsule, it suffered from two limitations: (1) the capsule had a small diameter, which provided a limited contact between SECM capsule and esophagus; and (2) speckle noise in SECM images made it challenging to appreciate cellular features. In this paper, we present a new SECM capsule, termed SECM half-inch tethered endoscopic capsule (HITEC), which addresses the two aforementioned technical challenges. With the SECM HITEC, a dual-clad fiber was used to reduce the speckle noise. Miniature GRIN optics was used to increase the NA of the fiber from 0.09 to 0.25, which made it possible to build a SECM capsule with large diameter (12.7 mm) while maintaining a short rigid length (22 mm). A water-immersion objective lens was custom designed and manufactured to provide high NA of 0.7. We have manufactured the SECM HITEC catheter and tested its optical and mechanical performance. Lateral and axial resolution was measured as 1.2 µm and 13 µm, respectively. We have imaged swine esophageal tissues ex vivo, and SECM images clearly visualized cell nuclei. Non-uniform rotational distortion (NURD) was small, less than 5%. Preliminary results suggest that SECM HITEC provides sufficient optical and mechanical performance for tissue imaging. In a future clinical study, we will test the feasibility of utilizing SECM HITEC for improved cellular imaging human of the human esophagus in vivo.

Recent advances in high-performance fluorescent and bioluminescent RNA imaging probes.

PubMed

Xia, Yuqiong; Zhang, Ruili; Wang, Zhongliang; Tian, Jie; Chen, Xiaoyuan

2017-05-22

RNA plays an important role in life processes. Imaging of messenger RNAs (mRNAs) and micro-RNAs (miRNAs) not only allows us to learn the formation and transcription of mRNAs and the biogenesis of miRNAs involved in various life processes, but also helps in detecting cancer. High-performance RNA imaging probes greatly expand our view of life processes and enhance the cancer detection accuracy. In this review, we summarize the state-of-the-art high-performance RNA imaging probes, including exogenous probes that can image RNA sequences with special modification and endogeneous probes that can directly image endogenous RNAs without special treatment. For each probe, we review its structure and imaging principle in detail. Finally, we summarize the application of mRNA and miRNA imaging probes in studying life processes as well as in detecting cancer. By correlating the structures and principles of various probes with their practical uses, we compare different RNA imaging probes and offer guidance for better utilization of the current imaging probes and the future design of higher-performance RNA imaging probes.

Bioresponsive probes for molecular imaging: concepts and in vivo applications.

PubMed

van Duijnhoven, Sander M J; Robillard, Marc S; Langereis, Sander; Grüll, Holger

2015-01-01

Molecular imaging is a powerful tool to visualize and characterize biological processes at the cellular and molecular level in vivo. In most molecular imaging approaches, probes are used to bind to disease-specific biomarkers highlighting disease target sites. In recent years, a new subset of molecular imaging probes, known as bioresponsive molecular probes, has been developed. These probes generally benefit from signal enhancement at the site of interaction with its target. There are mainly two classes of bioresponsive imaging probes. The first class consists of probes that show direct activation of the imaging label (from "off" to "on" state) and have been applied in optical imaging and magnetic resonance imaging (MRI). The other class consists of probes that show specific retention of the imaging label at the site of target interaction and these probes have found application in all different imaging modalities, including photoacoustic imaging and nuclear imaging. In this review, we present a comprehensive overview of bioresponsive imaging probes in order to discuss the various molecular imaging strategies. The focus of the present article is the rationale behind the design of bioresponsive molecular imaging probes and their potential in vivo application for the detection of endogenous molecular targets in pathologies such as cancer and cardiovascular disease. Copyright © 2015 John Wiley & Sons, Ltd.

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

PubMed

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.

Rectal Tumour Staging with Endorectal Ultrasound: Is There Any Difference between Western and Eastern European Countries?

PubMed

Fábián, Anna; Bor, Renáta; Farkas, Klaudia; Bálint, Anita; Milassin, Ágnes; Rutka, Mariann; Tiszlavicz, László; Wittmann, Tibor; Nagy, Ferenc; Molnár, Tamás; Szepes, Zoltán

2016-01-01

Background. Rectal tumour management depends highly on locoregional extension. Rectal endoscopic ultrasound (ERUS) is a good alternative to computed tomography and magnetic resonance imaging. However, in Hungary only a small amount of rectal tumours is examined with ERUS. Methods. Our retrospective study (2006-2012) evaluates the diagnostic accuracy of ERUS and compares the results, the first data from Central Europe, with those from Western Europe. The effect of neoadjuvant therapy, rectal probe type, and investigator's experience were also assessed. Results. 311 of the 647 ERUS assessed locoregional extension. Histological comparison was available in 177 cases: 67 patients underwent surgery alone; 110 received neoadjuvant chemoradiotherapy (CRT); ERUS preceded CRT in 77 and followed it in 33 patients. T-staging was accurate in 72% of primarily operated patients. N-staging was less accurate (62%). CRT impaired staging accuracy (64% and 59% for T- and N-staging). Rigid probes were more accurate (79%). At least 30 examinations are needed to master the technique. Conclusions. The sensitivity of ERUS complies with the literature. ERUS is easy to learn and more accurate in early stages but unnecessary for restaging after CRT. Staging accuracy is similar in Western and Central Europe, although the number of examinations should be increased.

Endoscopic feature tracking for augmented-reality assisted prosthesis selection in mitral valve repair

NASA Astrophysics Data System (ADS)

Engelhardt, Sandy; Kolb, Silvio; De Simone, Raffaele; Karck, Matthias; Meinzer, Hans-Peter; Wolf, Ivo

2016-03-01

Mitral valve annuloplasty describes a surgical procedure where an artificial prosthesis is sutured onto the anatomical structure of the mitral annulus to re-establish the valve's functionality. Choosing an appropriate commercially available ring size and shape is a difficult decision the surgeon has to make intraoperatively according to his experience. In our augmented-reality framework, digitalized ring models are superimposed onto endoscopic image streams without using any additional hardware. To place the ring model on the proper position within the endoscopic image plane, a pose estimation is performed that depends on the localization of sutures placed by the surgeon around the leaflet origins and punctured through the stiffer structure of the annulus. In this work, the tissue penetration points are tracked by the real-time capable Lucas Kanade optical flow algorithm. The accuracy and robustness of this tracking algorithm is investigated with respect to the question whether outliers influence the subsequent pose estimation. Our results suggest that optical flow is very stable for a variety of different endoscopic scenes and tracking errors do not affect the position of the superimposed virtual objects in the scene, making this approach a viable candidate for annuloplasty augmented reality-enhanced decision support.

Endoscopic ultrasound-guided biliary drainage

PubMed Central

Chavalitdhamrong, Disaya; Draganov, Peter V

2012-01-01

Endoscopic ultrasound (EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography (ERCP). EUS-guided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques. EUS-guided biliary drainage is an attractive option because of its minimally invasive, single step procedure which provides internal biliary decompression. Multiple investigators have reported high success and low complication rates. Unfortunately, high quality prospective data are still lacking. We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure. PMID:22363114

Endoscopic Ultrasound Elastography: Current Clinical Use in Pancreas.

PubMed

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.