1. Articles in category: Probes

    1-24 of 464 1 2 3 4 ... 18 19 20 »
    1. Dual-path handheld system for cornea and retina imaging using optical coherence tomography

      Dual-path handheld system for cornea and retina imaging using optical coherence tomography

      A dual-path handheld system is proposed for cornea and retina imaging using spectral domain optical coherence tomography. The handheld sample arm is designed to acquire two images simultaneously. Both eyes of a person can be imaged at the same time to obtain the images of the cornea of one eye and the retina of the other eye. Cornea, retina, and optic disc images are acquired with the proposed sample arm. Experimental results demonstrate the usefulness of this system for imaging of different eye segments. This system reduces the time required for imaging of the two eyes and is cost effective.

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    2. Endoscopic optical coherence tomography using compressive sensing

      Endoscopic optical coherence tomography using compressive sensing

      Conventionally endoscopic OCT images are reconstructed by uniform sampling in both axial and transverse direction of the image. To shorten the scanning time and reduce the acquisition data, we propose to sparsely sample the axial scans and use compressive sensing (CS) to reconstruct the full endoscopic OCT image with randomly chosen axial scans that are much less than conventional Nyquist criteria requirement. And we study the ratio of sparse sampling numerically and experimentally that are required to reconstruct acceptable OCT images. We demonstrate that the OCT image acquisition time can be significantly reduced because of much less acquired data.

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    3. Two-axis polydimethylsiloxane-based electromagnetic microelectromechanical system scanning mirror for optical coherence tomography

      Two-axis polydimethylsiloxane-based electromagnetic microelectromechanical system scanning mirror for optical coherence tomography

      Compact size and fast imaging abilities are key requirements for the clinical implementation of an optical coherence tomography (OCT) system. Among the various small-sized technology, a microelectromechanical system (MEMS) scanning mirror is widely used in a miniaturized OCT system. However, the complexities of conventional MEMS fabrication processes and relatively high costs have restricted fast clinical translation and commercialization of the OCT systems. To resolve these problems, we developed a two-axis polydimethylsiloxane (PDMS)-based MEMS (2A-PDMS-MEMS) scanning mirror through simple processes with low costs. It had a small size of 15 × 15 × 15    mm 3 15×15×15  mm3 , was fast ...

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    4. Miniaturization of plastic lens by injection molding for disposable endoscopie optical coherence tomography system

      Miniaturization of plastic lens by injection molding for disposable endoscopie optical coherence tomography system

      Minimally invasive robotic surgery required disposable endoscopie optical coherence tomography (OCT) for high-resolution deep tissue imaging and cross-contamination prevention. Here, we developed a miniaturized plastic lens by injection molding for developing a disposable endoscopie optical coherence tomography system for the first time. Injection molding provided low-cost and high-production rate to produce a disposable plastic lens and enabled the miniaturization of plastic lens. Transmittance and curvature of the plastic lens was measured. The plastic lens was integrated with an endoscopie OCT system, and the images of human-skin and microspheres embedded in agarose gel were captured. We are currently trying to integrate ...

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      Mentions: Ki Hean Kim
    5. Method and apparatus for automated scanning probe microscopy

      Method and apparatus for automated scanning probe microscopy

      This invention concerns scanning probe microscopes and related instruments ("SPMs") when used to investigate or measure large samples whose size is a multiple of the typical operational scanning area of an SPM, say 150 .mu.m.times.150 .mu.m at most. To avoid frequent readjustments or other time-consuming human interaction and errors when focusing the SPM, a multi-step, automated method for the SPM-scanning of large samples is disclosed, comprising a "coarse", i.e. low resolution, non-SPM scanning or mapping step adapted to scan a large sample and providing an integral map of the sample, followed by a preferably mathematical ...

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    6. Planar and Integrated MEMS Micromirrors Based Endoscopic Optical Coherence Tomography (Thesis)

      Planar and Integrated MEMS Micromirrors Based Endoscopic Optical Coherence Tomography (Thesis)

      Optical coherence tomography (OCT) is a thriving imaging modality which provides high-resolution, in vivo, real-time, non-invasive, cross-sectional imaging capability for biomedical applications. Over the past decade, OCT has become a standard clinical diagnosis tool for ophthalmology. However, human organs other than eyeballs are all highly scattering tissues, which limits the OCT penetration depth to ~2 mm. Therefore, endoscopic OCT probes with small diameter must be developed for imaging internal organs. The key component of an endoscopic OCT probe is the optical scanner. Thus, the first objective of this work is to develop miniature optical scanners using microelectromechanical system (MEMS) technology ...

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    7. Micrometer-resolution in-fiber OCT probe with tunable working distance

      Micrometer-resolution in-fiber OCT probe with tunable working distance

      Optical coherence tomography (OCT) is an attractive modality in biomedical imaging systems due to its non-invasive imaging character. Since the image quality of OCT may be limited by the decrease of transverse resolution away from the focus spot, working distance tunable probe can be a strategy to overcome such limitation and maintain high transverse resolution at different imaging depths. In this paper, a miniature, working distance-tunable in-fiber OCT probe is demonstrated. The influences of the graded index fiber (GIF) length as well as the air cavity length on the working distance and the transverse resolution are simulated and discussed. Experimental ...

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    8. Common-path optical coherence tomography using a microelectromechanical-system-based endoscopic probe

      Common-path optical coherence tomography using a microelectromechanical-system-based endoscopic probe

      This paper presents a common-path (CP) swept-source optical coherence tomography (SSOCT) system based on a special endoscopic probe design with an in-line internal reflection as the reference and a two-axis electrothermal microelectromechanical system mirror for image scanning. The rear surface of a gradient reflective index (GRIN) lens inside the probe is set as the reference reflection plane. The length of the GRIN lens is optimized to eliminate the artifacts in SSOCT images successfully. Doppler OCT is also demonstrated based on the CP endoscopic probe. The diameter of the probe is only 2.5 mm, so it can be easily inserted ...

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    9. Tomography probe

      Tomography probe

      An optical probe suitable for medical or dental tomography is switchable between a rotating and non-rotating mode to control interference between source signals and data signals. The probe is suitably constructed in an in-line configuration and uses Faraday rotators which rotate polarization in the same direction in a rotating mode and rotate polarization in opposite directions in a non-rotating mode.

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    10. University of Washington Receives NIH Grant for Needle Biopsy Preservation and Preparation for Rapid 2D Pathology of Pancreas

      University of Washington Receives NIH Grant for Needle Biopsy Preservation and Preparation for Rapid 2D Pathology of Pancreas

      University of Washington Receives a 2016 NIH Grant for $235,226 for Needle Biopsy Preservation and Preparation for Rapid 2D Pathology of Pancreas. The principal investigator is Eric Seibel. The program began in 2014 and ends in 2017. Below is a summary of the proposed work. There are over three million needle biopsies performed every year in the USA, typically for the diagnosis of breast, prostate, thyroid, lung, liver, and pancreatic cancers. Because needle biopsies are less invasive than surgical biopsies, they are much more cost-effective. However, a major limitation for all needle biopsies are that the pathologist or cytologist ...

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    11. Astigmatism corrected common path probe for optical coherence tomography

      Astigmatism corrected common path probe for optical coherence tomography

      Background and Objectives Optical coherence tomography (OCT) catheters for intraluminal imaging are subject to various artifacts due to reference-sample arm dispersion imbalances and sample arm beam astigmatism. The goal of this work was to develop a probe that minimizes such artifacts. Materials and Methods Our probe was fabricated using a single mode fiber at the tip of which a glass spacer and graded index objective lens were spliced to achieve the desired focal distance. The signal was reflected using a curved reflector to correct for astigmatism caused by the thin, protective, transparent sheath that surrounds the optics. The probe design ...

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    12. OCT probe using PZT

      OCT probe using PZT

      An optical coherence tomography (OCT) probe using lead zirconate titanate (PZT). In the OCT probe using PZT, a sine wave is induced from a vibrator made of a piezoelectric element, so that an image in which the scanning range is increased can be captured due to the vibration of the vibrator. A decrease in the vibration of the vibrator can be minimized by optimizing the position where the base fixes the vibrator.

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    13. Circumferential optical coherence tomography angiography imaging of the swine esophagus using a micromotor balloon catheter

      Circumferential optical coherence tomography angiography imaging of the swine esophagus using a micromotor balloon catheter

      We demonstrate a micromotor balloon imaging catheter for ultrahigh speed endoscopic optical coherence tomography (OCT) which provides wide area, circumferential structural and angiographic imaging of the esophagus without contrast agents. Using a 1310 nm MEMS tunable wavelength swept VCSEL light source, the system has a 1.2 MHz A-scan rate and ~8.5 µm axial resolution in tissue. The micromotor balloon catheter enables circumferential imaging of the esophagus at 240 frames per second (fps) with a ~30 µm (FWHM) spot size. Volumetric imaging is achieved by proximal pullback of the micromotor assembly within the balloon at 1.5 mm/sec ...

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    14. Deep tissue volume imaging of birefringence through fibre-optic needle probes for the delineation of breast tumour

      Deep tissue volume imaging of birefringence through fibre-optic needle probes for the delineation of breast tumour

      Identifying tumour margins during breast-conserving surgeries is a persistent challenge. We have previously developed miniature needle probes that could enable intraoperative volume imaging with optical coherence tomography. In many situations, however, scattering contrast alone is insufficient to clearly identify and delineate malignant regions. Additional polarization-sensitive measurements provide the means to assess birefringence, which is elevated in oriented collagen fibres and may offer an intrinsic biomarker to differentiate tumour from benign tissue. Here, we performed polarization-sensitive optical coherence tomography through miniature imaging needles and developed an algorithm to efficiently reconstruct images of the depth-resolved tissue birefringence free of artefacts. First ex ...

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    15. 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 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 , respectively. The resolution is limited by the pixel spacing of the coherent fiber ...

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    16. Combination optical and ultrasonic imaging of an eye

      Combination optical and ultrasonic imaging of an eye

      A method and apparatus are disclosed for integrating optical coherence tomography (OCT) and very high frequency ultrasound (VHFU) imaging systems. An OCT probe and reference arm are mounted along with an ultrasound probe on a carriage capable of rotational, linear, and/or arcuate motion. The probe carriage may be immersed in water or other suitable medium. The OCT and VHFU probes move about the cornea surface such that the probe axes are substantially perpendicular relative to the cornea surface throughout a scan. The probes are able to be scanned in an arcuate path across the entire cornea surface. The method ...

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    17. Imaging probes and associated devices, systems, and methods utilizing speaker actuators

      Imaging probes and associated devices, systems, and methods utilizing speaker actuators

      Devices, systems, and methods that utilize a speaker to impart motion to an optical fiber positioned within an imaging probe are provided. In some embodiments, an ophthalmic imaging apparatus comprises an optical probe having a handle sized and shaped for handheld grasping by a user; and a cannula coupled to the handle, the cannula sized and shaped for insertion into an eye to be treated; an optical fiber positioned at least partially within the optical probe, the optical fiber configured to receive an imaging light from an imaging light source and guide the imaging light to an optical element positioned ...

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    18. Spectrally encoded miniature endoscopic imaging probe

      Spectrally encoded miniature endoscopic imaging probe

      A spectrally encoded endoscopic probe having high resolution and small diameter comprising at least one flexible optical fiber; an energy source; a grating through which said energy is transmitted such that the energy spectrum is dispersed; a lens for focusing the dispersed energy spectrum onto a sample such that the impingement spot for each wavelength is a separate position on the sample, the wavelength spectrum defining a wavelength encoded axis; means for mechanically scanning the sample with focused energy in a direction perpendicular to the wavelength encoded axis; a means for receiving energy reflected from the sample; and, a means ...

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    19. Imaging probes and associated devices, systems, and methods utilizing lever arm actuators

      Imaging probes and associated devices, systems, and methods utilizing lever arm actuators

      Devices, systems, and methods that utilize a mechanical structure, such as a lever arm or a flexure mechanism, and an electrically energizable member, such as an actuator, to impart motion to an optical fiber positioned within an imaging probe are provided. In some embodiments, an ophthalmic imaging probe can include a handle; a cannula coupled to the handle; an optical fiber positioned at least partially within the handle and the cannula, the optical fiber configured to receive an imaging light from an imaging light source and guide the imaging light to an optical element positioned within a distal portion of ...

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    20. Optical deflection element and optical deflection device

      Optical deflection element and optical deflection device

      An optical deflection element is provided with a substrate; an optical waveguide film made of an electro-optic medium, and constituting an optical waveguide formed on the substrate; a first electrode pair disposed on an incident side of the optical waveguide film at a position facing a film thickness direction of the optical waveguide film, and configured to deflect a light beam transmitting through the optical waveguide film in an in-plane direction of the optical waveguide film in accordance with a first applied voltage; and a second electrode pair disposed on an output side of the optical waveguide film at a ...

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      Mentions: Panasonic
    21. Active depth-guding handheld micro-forceps for membranectomy based on CP-SSOCT

      Active depth-guding handheld micro-forceps for membranectomy based on CP-SSOCT

      In this study, we demonstrate a handheld motion-compensated micro-forceps system using common-path swept source optical coherence tomography with highly accurate depth-targeting and depth-locking for Epiretinal Membrane Peeling. Two motors and a touch sensor were used to separate the two independent motions: motion compensation and tool-tip manipulation. A smart motion monitoring and guiding algorithm was devised for precise and intuitive freehand control. Ex-vivo bovine eye experiments were performed to evaluate accuracy in a bovine retina retinal membrane peeling model. The evaluation demonstrates system capabilities of 40 um accuracy when peeling the epithelial layer of bovine retina.

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    22. A 2-axis Polydimethylsiloxane (PDMS) based electromagnetic MEMS scanning mirror for optical coherence tomography

      A 2-axis Polydimethylsiloxane (PDMS) based electromagnetic MEMS scanning mirror for optical coherence tomography

      Optical coherence tomography (OCT) is a noninvasive imaging tool for visualizing cross-sectional images of biological tissues on a microscale. Various microelectromechanical system (MEMS) techniques have been applied to OCT for endoscopic catheters and handheld probes. Despite having several advantages such as compact sizes and high speeds for real-time imaging, the complexities of the fabrication processes and relatively high costs were bottlenecks for fast clinical translation and commercialization of the earlier MEMS scanners. To overcome these issues, we developed a 2-axis polydimethylsiloxane (PDMS)-based electromagnetic MEMS scanning mirror based on flexible, cost-effective, and handleable PDMS. The size of this MEMS scanner ...

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    23. Optical coherence tomography probe design for reduced artifact generation and manufacturability

      Optical coherence tomography probe design for reduced artifact generation and manufacturability

      Many fiber based probes used in Optical Coherence Tomography (OCT) are comprised of a spacer, GRIN lens, fiber, and a microprism. This design form suffers from many material interfaces, which induce back reflections into the sample arm of the interferometer. With so many interfaces, these probes can produce artifacts in the system’s imaging window. We present a design which has just two interfaces to minimize image artifacts. The two components of this design are the fiber endface and a reflective optic. With optimization, these two components can produce back reflections below -90dB which will minimize image artifacts. This will ...

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      Mentions: Corning
    24. Interferometric force sensor for surgical instruments

      Interferometric force sensor for surgical instruments

      A surgical tool system according to an embodiment of the current invention includes a surgical tool, and an interferometry system optically coupled to the surgical tool. The surgical tool includes a body section, a sensor section at least one of attached to or integral with the body section, and a surgical section at least one of attached to or integral with the sensor section at an opposing end of the sensor section from the body section. The sensor section comprises an interferometric optical sensor defining a reference distance that changes in response to at least one of a force or ...

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    1-24 of 464 1 2 3 4 ... 18 19 20 »
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