1. Articles in category: Probes

    1-24 of 687 1 2 3 4 ... 27 28 29 »
    1. Bimodal endoscopic probe combining white-light microscopy and optical coherence tomography

      Bimodal endoscopic probe combining white-light microscopy and optical coherence tomography

      We present a novel bimodal endoscopic imaging probe that can simultaneously provide full-field white-light video microscopy and confocal optical coherence tomography (OCT) depth scans. The two modalities rely on spectrally separated optical paths that run partially in parallel through a micro-optical bench system, which has a cross-section of only 2   mm × 2.76   mm 2 mm×2.76 mm and is realized via standard silicon micromachining techniques. With a numerical aperture of 0.061, the video modality has a resolution and field of view of 9.3 and 1240   μm × 1080   μm 1240 μm×1080 μm , respectively. The resolution is ...

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    2. An optically-guided cochlear implant sheath for real-time monitoring of electrode insertion into the human cochlea

      An optically-guided cochlear implant sheath for real-time monitoring of electrode insertion into the human cochlea

      In cochlear implant surgery, insertion of perimodiolar electrode arrays into the scala tympani can be complicated by trauma or even accidental translocation of the electrode array within the cochlea. In patients with partial hearing loss, cochlear trauma can not only negatively affect implant performance, but also reduce residual hearing function. These events have been related to suboptimal positioning of the cochlear implant electrode array with respect to critical cochlear walls of the scala tympani (modiolar wall, osseous spiral lamina and basilar membrane). Currently, the position of the electrode array in relation to these walls cannot be assessed during the insertion ...

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    3. Novel microendoscope design improves bio-imaging

      Novel microendoscope design improves bio-imaging

      Microendoscopes using fiber optics are becoming increasingly important imaging tools, but they have physical limitations. They are essential for applications that require a long working distance, high resolution, and a minimum probe diameter. A paper in IEEE Photonics Journal by Karol Karnowski of Poland’s International Centre for Translational Eye Research , Gavrielle Untracht of Technical University of Denmark , Michael Hackmann of University of Western Australia , Onur Cetinkaya of ICTER and David Sampson of the University of Surrey, UK, sheds new light on modern microendoscopes. The researchers show that endoscopic imaging probes, particularly those for so-called side viewing, combining fiber-optic (GRIN ...

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    4. How to improve microendoscopes? New probe design brings promises to improve biomedical imaging

      How to improve microendoscopes? New probe design brings promises to improve biomedical imaging

      Microendoscopes are the cornerstone of modern medical diagnostics—they allow us to see what we could not even describe two decades ago. The technology is constantly improving, with ICTER scientists contributing to the development of the probes. Microendoscopes using fiber optics are becoming increasingly important imaging tools, but they have physical limitations. They are essential for applications that require a long working distance, high resolution, and a minimum probe diameter. A new research paper by Dr. Karol Karnowski of ICTER, Dr. Gavrielle Untracht of the Technical University of Denmark (DTU), Dr. Michael Hackmann of the University of Western Australia (UWA ...

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    5. Superior Imaging Performance of All-Fiber, Two-Focusing-Element Microendoscopes

      Superior Imaging Performance of All-Fiber, Two-Focusing-Element Microendoscopes

      All-fiber-optic imaging microendoscopes are emerging as an important tool in bioimaging studies, including those conducted with optical coherence tomography, but physical limitations constrain the achievable beam characteristics of designs using a single focusing element. These constraints are especially relevant for applications that require a long working distance, high resolution, and/or minimal probe diameter. Through detailed analysis based on ABCD matrix modelling, we show that side-viewing probes combining a graded-index (GRIN) fiber with a ball lens – GRIN-ball-lens probes (GBLPs) – offer superior performance over a range of numerical apertures and pave the way for a broader range of imaging applications. The ...

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    6. Atherectomy catheters with imaging

      Atherectomy catheters with imaging

      An atherectomy catheter includes an elongate flexible catheter body, an elongate deflectable distal tip coupled to the catheter body at a hinge point, a rotatable cutter near the distal end of the catheter body, and a drive shaft extending within the catheter body and configured to rotate the cutter. The atherectomy catheter further includes an optical fiber extending through the drive shaft substantially on-axis with the catheter body and attached to the cutter. The optical fiber is configured to rotate with the drive shaft. The atherectomy catheter further includes a wedge configured to deflect the distal tip away from the ...

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      Mentions: Avinger
    7. 3D-printed fiber-based zeroth- and high-order Bessel beam generator

      3D-printed fiber-based zeroth- and high-order Bessel beam generator

      Bessel beams (BBs) have gained prominence thanks to their diffraction-free propagation and self-healing properties. These beams are conventionally generated using different approaches, namely by transforming a narrow circular beam with a lens, using axicons or holographic beam-shaping techniques. These methods involve space-consuming optics. To overcome this limitation, in the past, efforts have been made to create BBs directly from optical fibers. However, these solutions have limited capability to generate BBs with on-demand optical parameters and only focused on creating zeroth-order BBs. Here, we propose a photonic structure that uses stacked miniaturized optical elements 3D printed in a single step on ...

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    8. Customized fiber generates Bessel beams

      Customized fiber generates Bessel beams

      An all fiber-based approach to generating special optical beams, called Bessel beams, could open up new applications in imaging, optical trapping and communications. Bessel beams look quite different from the usual Gaussian light beams found in optics. In particular, they possess several interesting properties including self-healing, diffraction-free propagation and the ability to carry orbital angular momentum (OAM). This family of beams—also known as vortex beams with a characteristic ring-like shape and a dark central region—include different "orders" of beams carrying different values of OAM.

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    9. Dual-modality fluorescence lifetime imaging-optical coherence tomography intravascular catheter system with freeform catheter optics

      Dual-modality fluorescence lifetime imaging-optical coherence tomography intravascular catheter system with freeform catheter optics

      Significance: Intravascular imaging is key to investigations into atherosclerotic plaque pathobiology and cardiovascular diagnostics overall. The development of multimodal imaging devices compatible with intracoronary applications has the potential to address limitations of currently available single-modality systems. Aim: We designed and characterized a robust, high performance multimodal imaging system that combines optical coherence tomography (OCT) and multispectral fluorescence lifetime imaging (FLIm) for intraluminal simultaneous assessment of structural and biochemical properties of coronary arteries. Approach: Several shortcomings of existing FLIm-OCT catheter systems are addressed by adopting key features, namely (1) a custom fiber optic rotary joint based on an air bearing, (2 ...

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      Mentions: UC Davis
    10. Flexible method for shaping laser beams extends depth-of-focus for OCT imaging

      Flexible method for shaping laser beams extends depth-of-focus for OCT imaging

      esearchers have developed a new method for flexibly creating various needle-shaped laser beams. These long, narrow beams can be used to improve optical coherence tomography (OCT), a noninvasive and versatile imaging tool that is used for scientific research and various types of clinical diagnoses. "Needle-shaped laser beams can effectively extend the depth-of-focus of an OCT system, improving the lateral resolution, signal-to-noise ratio, contrast and image quality over a long depth range," said research team leader Adam de la Zerda from Stanford University School of Medicine. "However, before now, implementing a specific needle-shaped beam has been difficult due to the lack ...

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    11. Flexible method for generating needle-shaped beams and its application in optical coherence tomography

      Flexible method for generating needle-shaped beams and its application in optical coherence tomography

      Needle-shaped beams (NBs) featuring a long depth-of-focus (DOF) can drastically improve the resolution of microscopy systems. However, thus far, the implementation of a specific NB has been onerous due to the lack of a common, flexible generation method. Here we develop a spatially multiplexed phase pattern that creates many axially closely spaced foci as a universal platform for customizing various NBs, allowing flexible manipulations of beam length and diameter, uniform axial intensity, and sub-diffraction-limit beams. NBs designed via this method successfully extended the DOF of our optical coherence tomography (OCT) system. It revealed clear individual epidermal cells of the entire ...

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    12. Multimodal imaging needle combining optical coherence tomography and fluorescence for imaging of live breast cancer cells labeled with a fluorescent analog of tamoxifen

      Multimodal imaging needle combining optical coherence tomography and fluorescence for imaging of live breast cancer cells labeled with a fluorescent analog of tamoxifen

      Significance: Imaging needles consist of highly miniaturized focusing optics encased within a hypodermic needle. The needles may be inserted tens of millimeters into tissue and have the potential to visualize diseased cells well beyond the penetration depth of optical techniques applied externally. Multimodal imaging needles acquire multiple types of optical signals to differentiate cell types. However, their use has not previously been demonstrated with live cells. Aim: We demonstrate the ability of a multimodal imaging needle to differentiate cell types through simultaneous optical coherence tomography (OCT) and fluorescence imaging. Approach: We characterize the performance of a multimodal imaging needle. This ...

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    13. MEMS-VCSEL swept-source optical coherence tomography for multi-MHz endoscopic ...

      MEMS-VCSEL swept-source optical coherence tomography for multi-MHz endoscopic ...

      Swept-source optical coherence tomography (SS-OCT) enables volumetric imaging of subsurface structure, but applications requiring wide fields of view, rapid imaging, and higher resolutions have been challenging because of the need for multi-MHz A-scan rates. Until now, achieving multi-MHz A-scan rates has been limited to Fourier-domain mode-locked lasers or stretched-pulse lasers. We describe a microelectromechanical-system, vertical-cavity surface-emitting laser (MEMS-VCSEL) for SS-OCT at A-scan rates of 2.4 and 3.0 MHz using a dual-channel acquisition system. Dual-channel operation enables simultaneous acquisition of Mach-Zehnder interferometer (MZI) fringes for sweep-to-sweep calibration and resampling, overcoming inherent optical clock limitations in state-of-the-art digitizers. We demonstrate ...

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    14. Flexible, high-resolution micro-optical coherence tomography endobronchial probe toward in vivo imaging of cilia

      Flexible, high-resolution micro-optical coherence tomography endobronchial probe toward in vivo imaging of cilia

      We report the design and fabrication of a flexible, longitudinally scanning high-resolution micro-optical coherence tomography (μOCT) endobronchial probe, optimized for micro-anatomical imaging in airways. The 2.4 mm diameter and flexibility of the probe allows it to be inserted into the instrument channel of a standard bronchoscope, enabling real-time video guidance of probe placement. To generate a depth-of-focus enhancing annular beam, we utilized a new fabrication method, whereby a hollow glass ferrule was angle-polished and gold-coated to produce an elongated annular reflector. We present validation data that verifies the preservation of linear scanning, despite the use of flexible materials. When ...

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    15. Passively scanned, single-fiber optical coherence tomography probes for gastrointestinal devices

      Passively scanned, single-fiber optical coherence tomography probes for gastrointestinal devices

      Background/objectives: Optical coherence tomography (OCT) uses low coherence interferometry to obtain depth-resolved tissue reflectivity profiles (M-mode) and transverse beam scanning to create images of two-dimensional tissue morphology (B-mode). Endoscopic OCT imaging probes typically employ proximal or distal mechanical beam scanning mechanisms that increase cost, complexity, and size. Here, we demonstrate in the gastrointestinal (GI) tracts of unsedated human patients, that a passive, single-fiber probe can be used to guide device placement, conduct device-tissue physical contact sensing, and obtain two-dimensional OCT images via M-to-B-mode conversion. Materials and methods: We designed and developed ultrasmall, manually scannable, side- and forward-viewing single fiber-optic ...

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    16. Ex-vivo evaluation of miniaturized probes for endoscopic optical coherence tomography in urothelial cancer diagnostics

      Ex-vivo evaluation of miniaturized probes for endoscopic optical coherence tomography in urothelial cancer diagnostics

      Background: The gold standard for detecting bladder cancer is white light cystoscopy (WLC) and resection of suspicious lesions. In this study, we evaluate two miniaturized Optical Coherence Tomography (OCT) probes for endoscopic use, regarding their applicability in diagnosing urothelial cancer. Materials and methods: In total, 33 patients who underwent a radical cystectomy were included. Preoperative oncological staging and determining the indication for the surgical intervention were done following the latest European Association of Urology (EAU) guidelines. Samples were taken from bladder tissue after bladder removal and prepared for OCT measurement. Additionally, porcine bladder samples were used as reference tissue. We ...

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    17. Epidural anesthesia needle guidance by forward-view endoscopic optical coherence tomography and deep learning

      Epidural anesthesia needle guidance by forward-view endoscopic optical coherence tomography and deep learning

      Epidural anesthesia requires injection of anesthetic into the epidural space in the spine. Accurate placement of the epidural needle is a major challenge. To address this, we developed a forward-view endoscopic optical coherence tomography (OCT) system for real-time imaging of the tissue in front of the needle tip during the puncture. We tested this OCT system in porcine backbones and developed a set of deep learning models to automatically process the imaging data for needle localization. A series of binary classification models were developed to recognize the five layers of the backbone, including fat, interspinous ligament, ligamentum flavum, epidural space ...

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    18. Methods, devices, and support structures for assembling optical fibers in catheter tips

      Methods, devices, and support structures for assembling optical fibers in catheter tips

      Described herein are methods, devices, and support structures for assembling optical fibers in catheter tips and facilitating alignment and structural support. A method for assembling a plurality of optical fibers and lenses in a support structure for an ablation catheter includes providing a support structure with a proximal end, a body, and a distal end, wherein the distal end includes a plurality of alignment orifices or slits.

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      Mentions: MedLumics
    19. Imaging probe with rotatable core

      Imaging probe with rotatable core

      The present disclosure provides for an imaging probe with a rotatable core which allows for rotating imaging assembly that is larger in diameter than the lumen in which the rotatable core resides, as well as methods to construct said probes. The imaging probes are generally elongate flexible imaging catheters for use in cardiovascular procedures.

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    20. Apparatus, device and method for capsule microscopy

      Apparatus, device and method for capsule microscopy

      An exemplary apparatus for obtaining data for at least one portion within at least one luminal or hollow sample can be provided. For example, the apparatus can include a first optical arrangement configured to transceive at least one electromagnetic radiation to and from the portion(s). The apparatus can also include a wavelength dispersive second arrangement, which can be configured to disperse the electromagnetic radiation(s). A housing can be provided with a shape of a pill, and enclosing the first and second arrangements.

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    21. In vivo PS-OCT needle probe scan of human skeletal muscle

      In vivo PS-OCT needle probe scan of human skeletal muscle

      Polarization-sensitive optical coherence tomography (PS-OCT) derived birefringence values effectively identify skeletal muscle structural disruption due to muscular dystrophy and exercise-related muscle damage in animal models in ex vivo tissue. The purpose of this investigation was to determine if a PS-OCT needle probe inserted into the leg of a human subject could accurately identify various anatomical structures with implications for use as a diagnostic tool for the determination of skeletal muscle pathology. A healthy middle-aged subject participated in this study. A custom-built PS-OCT system was interfaced with a side-viewing fiber-optic needle probe inserted into the subject’s vastus lateralis muscle via ...

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    22. Esophageal optical coherence tomography image synthesis using an adversarially learned variational autoencoder

      Esophageal optical coherence tomography image synthesis using an adversarially learned variational autoencoder

      Endoscopic optical coherence tomography (OCT) imaging offers a non-invasive way to detect esophageal lesions on the microscopic scale, which is of clinical potential in the early diagnosis and treatment of esophageal cancers. Recent studies focused on applying deep learning-based methods in esophageal OCT image analysis and achieved promising results, which require a large data size. However, traditional data augmentation techniques generate samples that are highly correlated and sometimes far from reality, which may not lead to a satisfied trained model. In this paper, we proposed an adversarial learned variational autoencoder (AL-VAE) to generate high-quality esophageal OCT samples. The AL-VAE combines ...

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    23. Dual-mode endoscope offers unprecedented insights into uterine health

      Dual-mode endoscope offers unprecedented insights into uterine health

      Researchers have developed a new endoscope that combines ultrasound with optical coherence tomography (OCT) to assess structural features of the lining of the uterus, called the endometrium, in unprecedented detail. The new probe could one day help doctors diagnose infertility problems that are related to endometrial receptivity with greater accuracy than current imaging technologies while reducing the need for invasive biopsies.

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    24. Integrated US-OCT-NIRF Tri-modality Endoscopic Imaging System for Pancreaticobiliary Duct Imaging

      Integrated US-OCT-NIRF Tri-modality Endoscopic Imaging System for Pancreaticobiliary Duct Imaging

      Pancreaticobiliary carcinomas is a highly malignant gastrointestinal tumor. Most pancreaticobiliary cancers arise from epithelial proliferations within the pancreaticobiliary ducts, referred to as pancreatic intraepithelial neoplasias (PanINs). Some PanINs are benign metaplasia, while others progress to invasive duct adenocarcinoma (IDAC). However, there is no standard programme to diagnose the progression from PanINs to IDAC. In this study, we present a tri-modality imaging system, which integrates ultrasound (US), optical coherence tomography (OCT), and near-infrared fluorescence (NIRF) for pancreaticobiliary duct imaging. This system can obtain OCT, US, and NIRF images in real time with a frame rate of 30 frames per second. For ...

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    1-24 of 687 1 2 3 4 ... 27 28 29 »
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    1. (2 articles) University of Western Australia
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