1. Articles in category: Probes

    241-264 of 512 « 1 2 ... 8 9 10 11 12 13 14 ... 20 21 22 »
    1. Full range spectral domain optical coherence tomography using a fiber-optic probe as a self-phase shifter

      Full range spectral domain optical coherence tomography using a fiber-optic probe as a self-phase shifter

      We present a full range handheld probe type spectral domain optical coherence tomography (SD-OCT) method. Here, the sample arm is composed of a tilted fiber-optic cantilever scanner; thus, the phase shift concurrently occurs while sample scanning. With the phase shift, we could achieve a full range complex-conjugate-free OCT image with no additional phase shifters in the reference arm. To realize this technique, a magnetically actuated probe was adopted. Full range SD-OCT images of a pearl, human fingernail, and human tooth were subsequently obtained using this suggested probe. The scanning range and acquisition speed were 3 mm and 20  frames/s ...

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    2. Numerical analysis of astigmatism correction in gradient refractive index lens based optical coherence tomography catheters

      Numerical analysis of astigmatism correction in gradient refractive index lens based optical coherence tomography catheters

      Endoscopic optical coherence tomography (OCT) catheters comprise a transparent tube to separate the imaging instrument from tissues. This tube acts as a cylindrical lens, introducing astigmatism into the beam. In this report, we quantified this negative effect using optical simulations of OCT catheter devices, and discuss possible compensation strategies. For esophageal imaging, the astigmatism is aggravated by the long working distance. For intracoronary imaging, the beam quality is degraded due to the liquid imaging environment. A nearly circular beam profile can be achieved by a curved focusing optics. We also consider the method of matching refractive indices, and it is ...

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    3. Rotation transmitting mechanism and optical scanning probe

      Rotation transmitting mechanism and optical scanning probe

      A rotation transmitting mechanism comprises: a three-layered coil that has an innermost layer coil portion, a middle layer coil portion and an outermost layer coil portion with alternating winding directions; and at least one elastic band that is fit to an outer peripheral area of said three-layered coil to press said outermost layer coil portion toward an inner peripheral side.

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    4. Apparatus for generating sectional images of tissue

      Apparatus for generating sectional images of tissue

      A generation of sectional images of tissue is provided. In this arrangement a first light-conducting fiber of a device for generating sectional tissue images according to the optical coherence tomography principle, which light-conducting fiber is rotatably accommodated within a catheter tube, is additionally connected to a device for generating light in a further wavelength range and for detecting fluorescent light. With its use sectional tissue images produced according to the optical coherence tomography principle can be superimposed with fluorescent images.

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      Mentions: Siemens
    5. Article and method for applying a coupling agent for a non-invasive optical probe

      Article and method for applying a coupling agent for a non-invasive optical probe

      This invention provides an article of manufacture and method for controlling the application of a coupling agent, such as a silicone oil or mineral oil, on a surface of a tissue prior to contacting the tissue with an apparatus for non-invasive optical measurement of the concentration of an analyte. The article ensures that a specific quantity of the coupling agent is deposited in a uniform layer over the entire target area of the tissue, thereby enhancing both the optical signal and the repeatability of thermal and optical coupling with the components of the apparatus. The article comprises a backing and ...

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    6. Feature Of The Week 7/8/12: University of Western Australia Demostrates Freehand Lateral Scanning of OCT Needle Probes

      Feature Of The Week 7/8/12: University of Western Australia Demostrates Freehand Lateral Scanning of OCT Needle Probes

      The University of Western Australia has been very active in advancing the field of OCT needle probes (e.g. search "needle probe" or similar searches in search box). This includes: making ultra-small probes, developing high-quality 3D imaging in needles, developing novel depth of focus extension techniques, and investigating the technology in human breast cancer patients, Recently they have published on a technique to allow for free hand lateral scanning of an OCT needle probe using a magnetic tracking system. Below is a summary of this recent work. -Eric Swanson We present a high-resolution three-dimensional position tracking method that allows an ...

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    7. Static and dynamic imaging of alveoli using optical coherence tomography needle probes

      Static and dynamic imaging of alveoli using optical coherence tomography needle probes

      Imaging of alveoli in situ has for the most part been infeasible due to the high resolution required to discern individual alveoli and limited access to alveoli beneath the lung surface. In this study, we present a novel technique to image alveoli using optical coherence tomography (OCT). We propose the use of OCT needle probes, where the distal imaging probe has been miniaturized and encased within a hypodermic needle (as small as 30-gauge, outer diameter 310 μm), allowing insertion deep within the lung tissue with minimal tissue distortion. Such probes enable imaging at a resolution of ~12 μm within a ...

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    8. Optical tomographic imaging apparatus including a beam scattering structure

      Optical tomographic imaging apparatus including a beam scattering structure

      In the optical tomographic imaging apparatus according to an aspect of the present invention, since a stable light intensity can be secured for a reflected light beam of a measurement light beam reflected off of a transmitting surface of a probe outer casing as a returning light beam to an optical fiber, the optical path length difference between a reference light beam and the measurement light beam can be precisely adjusted by adjusting the optical path length of the reference light beam with an optical path length adjusting device. In addition, a signal of a measurement object can be reliably ...

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    9. Scanning mechanisms for imaging probe

      Scanning mechanisms for imaging probe

      The present invention provides scanning mechanisms for imaging probes for imaging mammalian tissues and structures using high resolution imaging, including high frequency ultrasound and/or optical coherence tomography. The imaging probes include adjustable rotational drive mechanism for imparting rotational motion to an imaging assembly containing either optical or ultrasound transducers which emit energy into the surrounding area. The imaging assembly includes a scanning mechanism including a movable member configured to deliver the energy beam along a path out of said elongate hollow shaft at a variable angle with respect to said longitudinal axis to give forward and side viewing capability ...

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    10. All-Fiber Probes Hold Promise for Medical Imaging Applications

      All-Fiber Probes Hold Promise for Medical Imaging Applications

      Optical fiber probes are still in the early stages of manufacturing, but filament fusion technology enables many probe designs, from ball lenses to fiber lenses, among others. Cleaving fiber bundles with high quality and good throughput facilitates their manufacturing and provides a cost-effective solution for device makers. Optical fiber components have been widely used in optical communication, fiber laser systems, fiber optic gyroscopes and fiber sensing applications. Recently, fiber optic probes have been adopted for in vivo optical imaging of internal tissues via optical coherent tomography (OCT), a technology used for morphological imaging of biological systems such as the retina ...

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    11. Intravascular atherosclerotic imaging with combined fluorescence and optical coherence tomography probe based on a double-clad fiber combiner

      Intravascular atherosclerotic imaging with combined fluorescence and optical coherence tomography probe based on a double-clad fiber combiner

      We developed a multimodality fluorescence and optical coherence tomography probe based on a double-clad fiber (DCF) combiner. The probe is composed of a DCF combiner, grin lens, and micromotor in the distal end. An integrated swept-source optical coherence tomography and fluorescence intensity imaging system was developed based on the combined probe for the early diagnoses of atherosclerosis. This system is capable of real-time data acquisition and processing as well as image display. For fluorescence imaging, the inflammation of atherosclerosis and necrotic core formed with the annexin V–conjugated Cy5.5 were imaged. Ex vivo imaging of New Zealand white rabbit ...

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    12. Torque limiter for an OCT catheter

      Torque limiter for an OCT catheter

      An apparatus comprising a torque wire connected to an imaging probe; and a torque limiter defining a bore, a first end of the torque limiter being in mechanical communication with a motor, a second end of the torque limiter being in mechanical communication with the torque wire, the torque wire being disposed through the bore of the torque limiter. The torque limiter comprises a member defining at least one cutout which causes the torque limiter to break when rotational force on the torque wire exceeds a predetermined amount, thereby decoupling the motor from the torque wire.

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      Mentions: St. Jude Medical
    13. Forward imaging OCT endoscopic catheter based on MEMS lens scanning

      Forward imaging OCT endoscopic catheter based on MEMS lens scanning

      This Letter reports a fully packaged microelectromechanical system (MEMS) endoscopic catheter for forward imaging optical coherence tomography (OCT). Two-dimensional optical scanning of Lissajous patterns was realized by the orthogonal movement of two commercial aspherical glass lenses laterally mounted on two resonating electrostatic MEMS microstages at low operating voltages. The MEMS lens scanner was integrated on a printed circuit board and packaged with an aluminum housing, a gradient index fiber collimator, and an objective lens. A home-built spectral-domain OCT system with 60 kHz A-line acquisition rate was combined with the endoscopic MEMS catheter. Three-dimensional images of 256×256×995 voxels were ...

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    14. Chemically Etched Single Mode Fiber Tip for High Lateral Resolution Imaging in Optical Coherence Tomography

      Chemically Etched Single Mode Fiber Tip for High Lateral Resolution Imaging in Optical Coherence Tomography

      In this paper, we propose a high lateral resolution common-path Fourier domain optical coherence tomography (OCT) system with the use of a chemically etched single mode fibre. In our experiments, a single mode optical fibre of 840 nm was used for preparing the tapered tips. Our system used a conical microlens that was chemically etched by a selective chemical etching technique using an etching solution of buffered hydrofluoric acid (BHF). From the experimental results, we verified that our proposed optical coherence tomography system could operate as a common-path Fourier domain OCT system and the apex angle of the chemically etched ...

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    15. Method and apparatus for monitoring blood constituent levels in biological tissue

      Method and apparatus for monitoring blood constituent levels in biological tissue

      In accordance with the invention, a low coherence interferometer is used to non-invasively monitor the concentration of glucose in blood by shining a light over a surface area of human or animal tissue, continuously scanning the light over a two dimensional area of the surface, collecting the reflected light from within the tissue and constructively interfering this reflected light with light reflected along a reference path to scan the tissue in depth. Since the reflection spectrum is sensitive to glucose concentration at particular wavelengths, measurement and analysis of the reflected light provides a measure of the level of glucose in ...

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    16. Optical Coherence Tomography And Illumination Using Common Light Source

      Optical Coherence Tomography And Illumination Using Common Light Source

      A light source for a surgical system includes a broadband light source operable to produce broadband light. The light source further includes a wavelength splitter adapted to split the broadband light into illumination light having a spectral range covering at least a majority of the visible spectrum and surgical light having a spectral range outside of the spectral range of the illumination light. The light source then includes at least one surgical module adapted to control application of the surgical light. The light source also includes first and second coupling optics. The first coupling optics are configured to optically couple ...

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    17. Enabling freehand lateral scanning of optical coherence tomography needle probes with a magnetic tracking system

      Enabling freehand lateral scanning of optical coherence tomography needle probes with a magnetic tracking system

      We present a high-resolution three-dimensional position tracking method that allows an optical coherence tomography (OCT) needle probe to be scanned laterally by hand, providing the high degree of flexibility and freedom required in clinical usage. The method is based on a magnetic tracking system, which is augmented by cross-correlation-based resampling and a two-stage moving window average algorithm to improve upon the tracker's limited intrinsic spatial resolution, achieving 18 µm RMS position accuracy. A proof-of-principle system was developed, with successful image reconstruction demonstrated on phantoms and on ex vivo human breast tissue validated against histology. This freehand scanning method could ...

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    18. Miniature actuator mechanism for intravascular imaging

      Miniature actuator mechanism for intravascular imaging

      The present invention relates to a new intravascular imaging device based on a Shape Memory Alloy (SMA) actuator mechanism embedded inside an elongate member such as a guide wire or catheter. The present invention utilizes a novel SMA mechanism to provide side-looking imaging by providing movement for an ultrasound transducer or optical coherence tomography (OCT) element. This novel SMA actuator mechanism can be easily fabricated in micro-scale, providing an advantage over existing imaging devices because it offers the ability to miniaturize the overall size of the device, while the use of multiple transducer crystals maximizes field of view of ultrasound ...

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    19. Intraoperative handheld optical coherence tomography forward-viewing probe: physical performance and preliminary animal imaging

      Intraoperative handheld optical coherence tomography forward-viewing probe: physical performance and preliminary animal imaging

      A prototype intraoperative hand-held optical coherence tomography (OCT) imaging probe was developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic probe was designed based on electrostatically driven optical fibers, and packaged into a catheter probe in the form factor of clinically accepted Bayonet shaped neurosurgical probes. Optical properties of the probe were measured to have a ~20 μm spot size, 5 mm working distance and 4 mm field of view. Feasibility of this probe for structural and Doppler shift imaging was tested on porcine femoral blood vessel imaging.

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    20. Methods and devices for image-guided manipulation or sensing or anatomic structures

      Methods and devices for image-guided manipulation or sensing or anatomic structures

      Forward-looking ultrasound transducers are positioned at the tip of a transseptal catheter to facilitate transseptal puncture and interventions within the left atrium, pulmonary veins and mitral valve. Catheter devices and systems are guided by forward-looking ultrasound or optical coherence tomography imaging for penetrating from one location within a mammalian patient's body to another location, and/or performing diagnostic or therapeutic interventions. A penetrator, diagnostic, or interventional device (eg. probe, biopsy apparatus, electrode, needle) is positioned at the catheter tip and is advanceable from the catheter to a target location outside of the lumen in which the catheter is positioned ...

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    21. Optical tomographic imaging system

      Optical tomographic imaging system

      The optical tomographic imaging system includes a main body for acquiring an optical tomographic image, an optical probe having a rotary optical fiber for guiding the measuring and returning light, a measuring unit, and a sheath rotatably holding the rotary optical fiber and the measuring unit, a rotary drive unit for rotatably coupling the rotary optical fiber to a stationary optical fiber connected with the main body, an extra length handling mechanism for winding the optical probe into a loop having at least a minimum diameter and an attaching unit removably attaching the optical probe. The extra length handling mechanism ...

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    22. Ultrathin fiber probes with extended depth of focus for optical coherence tomography

      Ultrathin fiber probes with extended depth of focus for optical coherence tomography

      We report on a novel scheme for extending the depth of focus (DOF) of ultrathin (125 μm diameter) fiber probes for optical coherence tomography (OCT) using a simple phase mask consisting of graded-index (GRIN) fiber. The technique is compatible with existing all-in-fiber probe fabrication techniques, and our simulations show that it can provide a DOF gain of ∼2 at a modest ∼5  dB reduction of peak sensitivity. In a prototype device using commercially available GRIN fiber, a DOF gain of 1.55 is obtained, validated by beam profiling and OCT imaging.

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    23. Optical structure measuring apparatus and optical probe thereof

      Optical structure measuring apparatus and optical probe thereof

      In an embodiment of the present invention, an OCT probe is configured by including: a thin and long substantially cylindrical sheath whose distal end is closed; an n-reflecting surface body, as an irradiating device, which has n reflecting surfaces (with n being an integer of three or more) and which is provided in a distal end portion of the sheath; a torque transmitting coil, as a rotating device, which is provided along the longitudinal axis of the sheath and which transmits rotational torque for rotating each of the reflection surfaces of the n-reflecting surface body about the longitudinal axis of ...

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    24. Real-time three-dimensional optical coherence tomography image-guided core-needle biopsy system

      Real-time three-dimensional optical coherence tomography image-guided core-needle biopsy system

      Advances in optical imaging modalities, such as optical coherence tomography (OCT), enable us to observe tissue microstructure at high resolution and in real time. Currently, core-needle biopsies are guided by external imaging modalities such as ultrasound imaging and x-ray computed tomography (CT) for breast and lung masses, respectively. These image-guided procedures are frequently limited by spatial resolution when using ultrasound imaging, or by temporal resolution (rapid real-time feedback capabilities) when using x-ray CT. One feasible approach is to perform OCT within small gauge needles to optically image tissue microstructure. However, to date, no system or core-needle device has been developed ...

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    241-264 of 512 « 1 2 ... 8 9 10 11 12 13 14 ... 20 21 22 »
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    1. (1 articles) UC Irvine
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    1. (1 articles) Julia Walther
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