1. Articles in category: Probes

    241-264 of 464 « 1 2 ... 8 9 10 11 12 13 14 ... 18 19 20 »
    1. A forward-imaging needle-type OCT probe for image guided stereotactic procedures

      A forward-imaging needle-type OCT probe for image guided stereotactic procedures
      A forward-imaging needle-type optical coherence tomography (OCT) probe with Doppler OCT (DOCT) capability has the potential to solve critical challenges in interventional procedures. A case in point is stereotactic neurosurgery where probes are advanced into the brain based on predetermined coordinates. Laceration of blood vessels in front of the advancing probe is an unavoidable complication with current methods. Moreover, cerebrospinal fluid (CSF) leakage during surgery can shift the brain rendering the predetermined coordinates unreliable. In order to address these challenges, we developed a forward-imaging OCT probe (740 μm O.D.) using a gradient-index (GRIN) rod lens that can provide real-time ...
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    2. Scanning and Tunable Micro-Optics for Endoscopic Optical Coherence Tomography

      Scanning and Tunable Micro-Optics for Endoscopic Optical Coherence Tomography
      The design, fabrication, and integration of micro-optical components for beam focus and steering are demonstrated in an endoscopic optical coherence tomography (OCT) system. The relevant components, a membrane-based microfluidic tunable microlens and an electrostatic 2-D scanning micromirror, are fabricated using silicon and polymer-based microelectromechanical system technologies. All components are assembled inside a 4.5 $muhbox{m}$ diameter probe. The design of the optical system, including substantiation of the need for focal length tunability, is presented, along with performance data of an OCT system using these components. A lateral resolution of about 13 $muhbox{m}$ is achieved, an improvement over fixed-focal ...
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    3. Feature Of The Week 11/27/11: Langevin Institute and LLTech Investigate In Vivo Cellular Full-Field OCT Imaging with a Rigid Endoscopic Probe

      Feature Of The Week 11/27/11: Langevin Institute and LLTech Investigate In Vivo Cellular Full-Field OCT Imaging with a Rigid Endoscopic Probe

      Full-Field OCT (FFOCT) is a particular approach of OCT that directly takes “en face” 2-D images with an isotropic resolution around 1µm [1]. With such a high resolution FFOCT systems can produce images that are similar to that obtained with classical histology procedures and can thus be important tools for pathology [2]. This is why we want to combine the interest of a setup with a needle probe with the performances of FFOCT.A FFOCT system with probe has to address the problem of keeping the performances of FFOCT in a setup using a miniaturized, medically safe probe. As proposed ...

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    4. Endoscope two dimensional scanning fiber probe and the driving method

      Endoscope two dimensional scanning fiber probe and the driving method
      We design and fabricate an endoscope scanning fiber probe based on the piezoelectric transducer (PZT) for optical coherence tomography (OCT) to perform two-dimensional scanning. The driving part of the optical fiber probe is composed of two piezoelectric ceramics and a thin conductive substrate. The optical fiber is fixed in the middle of the piezoelectric ceramics to form a configuration of cantilever. A sine wave is employed for driving the PZT to make the cantilever vibrate along the vertical direction and form a line scanning. A saw tooth wave is load on the PZT to make the cantilever vibrate along the ...
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    5. Catheter system and method for boring through blocked vascular passages

      Catheter system and method for boring through blocked vascular passages
      A rotating cutting head catheter for passage through chronic total occlusions or other refractory atherosclerotic plaque from diseased arteries is disclosed. The catheter's rotating cutting head is designed to reside safely within an outer protective sheath when not in use. The outer protective sheath contains one or more helical grooves or slots, and the cutting head contains protruding blades or projections that fit into these helical grooves or slots. Application of torque to an inner catheter or wire attached to the cutting head applies spin to the cutting head, and the force of the sheath's helical grooves or ...
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    6. Portable optical coherence tomography (OCT) devices and related systems

      Portable optical coherence tomography (OCT) devices and related systems
      Portable optical coherence tomography (OCT) devices including at least one mirror configured to scan at least two directions are provided. The portable OCT devices are configured to provide a portable interface to a sample that can be aligned to the sample without repositioning the sample. Related systems are also provided.
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    7. Numerical simulation of a gradient-index fibre probe and its properties of light propagation

      Numerical simulation of a gradient-index fibre probe and its properties of light propagation
      In order to verify the properties of the light propagating through a gradient-index (GRIN) fibre probe for optical coherence tomography (OCT), numerical simulation using the optical software GLAD is carried out. Firstly, the model of the GRIN fibre probe is presented, which is consisted of a single mode fibre (SMF), a no-core fibre (NCF), a GRIN fibre lens and an air path. Then, the software GLAD is adopted to numerically investigate how the lengths of the NCF and the GRIN fibre lens influence the performance of the Gaussian beam focusing through the GRIN fibre probe. The simulation results are well ...
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    8. Stationary-fiber rotary probe with unobstructed 360° view for optical coherence tomography

      Stationary-fiber rotary probe with unobstructed 360° view for optical coherence tomography
      A side-scanning fiber probe is a critical component for optical coherence tomography in medical imaging and diagnosis. We propose and fabricate an on-axis rotating probe that performs in situ, circumferential scanning that is shadow-free (not susceptible to shadow effects caused by the motor’s wires). A miniature motor that incorporates a bored-out shaft for the optical fiber is located at the distal end of the probe, which results in a more stable and uniform circumferential scan, free from wire-shadow interference effects. More importantly, this design, novel to our knowledge, compared to other probes avoids the insertion losses introduced by optical ...
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    9. Multimodal catheter system and method for intravascular analysis

      Multimodal catheter system and method for intravascular analysis
      Methods, apparatus, and systems for intravascular analysis combine at least three analytical modalities. In one implementation, intravascular ultrasound, optical coherence tomography, and near infrared spectroscopy are combined to enable detection of multiple, different abnormalities in the arterial morphology during a single intravascular procedure.
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      Mentions: InfraReDx
    10. High capacity debulking catheter with distal driven cutting wheel

      High capacity debulking catheter with distal driven cutting wheel
      An atherectomy catheter includes a rotary cutting knife that is driven from the distal (nose) or side (circumference) direction. The catheter collects plaque shavings in a hollow collection chamber mounted in between the rotary cutting knife and the main catheter tubing. In contrast to prior art designs, which utilized nose mounted plaque collection chambers, the present design is able to store a substantially larger volume of removed plaque, thus increasing the length of time and amount of plaque removal that can be accomplished before the catheter must be removed from the body and cleaned. This decreases medical procedure time, allows ...
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    11. Optical rotary adapter and optical tomographic imaging system using the same

      Optical rotary adapter and optical tomographic imaging system using the same
      The optical rotary adapter is used with an optical tomographic imaging system for acquiring an optical tomographic image of an object under measurement. The adapter includes a fixed sleeve, a stationary optical fiber supported by the fixed sleeve and having an inclined end face, a stationary collimating lens spaced a given distance from the inclined end face, a mounting cylinder carried rotatably with respect to the fixed sleeve, a rotary optical fiber mounted to the mounting cylinder and having an inclined end face, a rotary collimating lens mounted to the mounting cylinder and disposed with a given distance from the ...
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    12. Miniature Optical Elements For Fiber-Optic Beam Shaping

      Miniature Optical Elements For Fiber-Optic Beam Shaping
      In part, the invention relates to optical caps having at least one lensed surface configured to redirect and focus light outside of the cap. The cap is placed over an optical fiber. Optical radiation travels through the fiber and interacts with the optical surface or optical surfaces of the cap, resulting in a beam that is either focused at a distance outside of the cap or substantially collimated. The optical elements such as the elongate caps described herein can be used with various data collection modalities such optical coherence tomography. In part, the invention relates to a lens assembly that ...
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    13. Full-range Fourier domain optical coherence tomography imaging probe with a magnetic-driven resonant fiber cantilever

      Full-range Fourier domain optical coherence tomography imaging probe with a magnetic-driven resonant fiber cantilever
      In this work, we developed a full-range Fourier domain optical coherence tomography (FD-OCT) imaging probe with a magnetic-driven resonant fiber cantilever. A galvanometer-driven reference mirror provides a linear phase modulation to each M-scan/B-scan frame to enable complex conjugate-free, full-range FD-OCT imaging. A fiber cantilever inside the probe is driven by a low-voltage miniature magnetic transducer. The fiber cantilever scans at its resonant frequency synchronized to the phase modulation induced by the reference mirror. Using a CCD line-scan camera-based spectrometer, we demonstrated real-time full-range FD-OCT at 34 frame/s (1024 pixel lateral × 2048 pixel axial).
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    14. In vivo and in situ cellular imaging full-field optical coherence tomography with a rigid endoscopic probe

      In vivo and in situ cellular imaging full-field optical coherence tomography with a rigid endoscopic probe
      Full-field OCT has proved to be a powerful high-resolution cellular imaging tool for biological tissues. However the standard bulk full-field OCT setup does not match the size requirements for most in situ and in vivo imaging applications. We adapted its principle into a rigid needle-like probe using two coupled interferometers and incoherent illumination: an external processing interferometer is used for in-depth scanning, while a distal common-path interferometer at the tip of the probe collects light backscattered from the tissue. Our experimental setup achieves an axial and transversal resolution in tissue of 1.8 µm and 3.5 µm respectively, for ...
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    15. Multiple beam source for a multi-beam interferometer and multi-beam interferometer

      Multiple beam source for a multi-beam interferometer and multi-beam interferometer
      A multi-beam interferometer, typically for use in Optical Coherence Tomography, comprising a multiple beam source, the source being arranged so as to provide, in use, a plurality of beams of light for use in the interferometer, the source comprising: a light source arranged to, in use, emit a beam of light; and a rattle plate comprising a first reflective surface and a second reflective surface facing one another, the second reflective surface being only partially reflective.
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    16. Ultrathin side-viewing needle probe for optical coherence tomography

      Ultrathin side-viewing needle probe for optical coherence tomography

      We present the smallest reported side-viewing needle probe for optical coherence tomography (OCT). Design, fabrication, optical characterization, and initial application of a 30-gauge (outer diameter 0.31 mm) needle probe are demonstrated. Extreme miniaturization is achieved by using a simple all-fiber probe design incorporating an angle-polished and reflection-coated fiber-tip beam deflector. When inserted into biological tissue, aqueous interstitial fluids reduce the probe’s inherent astigmatism ratio to 1.8, resulting in a working distance of 300 μm and a depth-of-field of 550 μm with beam diameters below 30 μm. The needle probe was interfaced with an 840 nm spectral-domain OCT ...

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    17. What Are Safe Margins of Resection for Invasive and In Situ Breast Cancer?

      What Are Safe Margins of Resection for Invasive and In Situ Breast Cancer?
      equate surgical margins in breast-conserving surgery are an important predictor of local recurrence (LR) rates. The definition of tumor-free margins in National Surgical Adjuvant Breast and Bowel Project (NSABP) trials requires that tumor cells do not touch ink, but subsequent retrospective single-institution studies have suggested that wider margins confer greater protection against LR. Particularly wide margins have been proposed for ductal carcinoma in situ. However, wider margin requirements lead to higher re-excision rates, with attendant economic, psychological, and cosmetic costs, and perhaps increased mastectomy rates. Juxtaposed against these concerns about optimal margin width, a meta-analysis of clinical trials has demonstrated ...
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    18. Feature Of The Week 9/11/11: Researchers at University of Florida Probe Into Miniature MEMs for OCT Imaging

      Feature Of The Week 9/11/11: Researchers at University of Florida Probe Into Miniature MEMs for OCT Imaging
      Researchers at the University of Florida, let by Dr. Huikai Xie, have been active for many years in developing advanced optical scanning technology using MEMS technology. Such technology is important for OCT and other optical imaging modalities. Below is a summary of some of their recent work.Endoscopic optical coherence tomography (OCT) imaging is very useful since it can replace risky, painful and time-consuming biopsy. However Endoscopic OCT is also very challenging, because fast lateral optical scan must be realized in a small imaging probe that must be able to fit into the small biopsy channel of endoscopes. MEMS technology ...
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    19. Design optimization and implementation of a miniature optical coherence tomography probe based on a MEMS mirror

      Design optimization and implementation of a miniature optical coherence tomography probe based on a MEMS mirror
      Optical coherence tomography (OCT) provides non-invasive cross-sectional imaging capability and high resolution, but it has very limited applications inside human body because of the stringent size requirements for accessing the internal organs. Micro-Electro-Mechanical Systems (MEMS) is an emerging technology that can make devices with small size and fast speed. This paper reports the design optimization of a MEMS mirror-based miniature OCT probe. The probe consists of three main parts: a GRIN lens module (1.3 mm in diameter), a MEMS mirror (1.7 mm x 1.55 mm), and a stainless steel mount. A special assembly holder is designed for ...
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    20. Common-path low-coherence interferometry fiber-optic sensor guided microincision

      Common-path low-coherence interferometry fiber-optic sensor guided microincision
      We propose and demonstrate a common-path low-coherence interferometry (CP-LCI) fiber-optic sensor guided precise microincision. The method tracks the target surface and compensates the tool-to-surface relative motion with better than ±5 μm resolution using a precision micromotor connected to the tool tip. A single-fiber distance probe integrated microdissector was used to perform an accurate 100 μm incision into the surface of an Intralipid phantom. The CP-LCI guided incision quality in terms of depth was evaluated afterwards using three-dimensional Fourier-domain optical coherence tomography imaging, which showed significant improvement of incision accuracy compared to free-hand-only operations.
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    21. Analytical method for designing gradient-index fiber probes

      Analytical method for designing gradient-index fiber probes
      An analytical method was investigated to design the gradient-index (GRIN) fiber probe based on characteristic parameters of a Gaussian beam propagating through the probe. First, a typical model of the GRIN fiber probe was presented, consisting of a single mode fiber, a no-core fiber (NCF), and a GRIN fiber lens. Second, a complex beam parameter matrix transformation method was adopted to derive the mathematical expressions of characteristic parameters, such as beam waist location, beam waist radius, and Rayleigh range. Then, MATLAB software was used to analyze the impact of the length of NCF and the length of the GRIN fiber ...
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    22. Catheters for optical coherence tomography

      Catheters for optical coherence tomography

      The objective of this review article is to overview technology, clinical evidence, and future applications to date optical coherence tomography (OCT) probes to yield the diagnostic purpose. We have reviewed the designing, construction and working of different categories of OCT probes developed for optical diagnostics having a potential for non invasive and improved detection of different types of cancer as well as other neoplasm. Rotational and balloon catheters, imaging needles and hand-held, linear scanning, multichannel, micro electro mechanical systems (MEMS) technology based, dynamic focusing, forward view imaging, and common path interferometer based probes have been discussed in details. The fiber ...

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    23. Microball lens integrated fiber probe for optical frequency domain imaging

      Microball lens integrated fiber probe for optical frequency domain imaging
      An integrated microball lens fiber catheter probe is demonstrated, which has better lateral resolution and longer working distance than a corresponding bare fiber probe with diverging beam for Fourier domain optical coherence tomography (FDOCT). Simulation results are shown to gain the effect of the distance between the microball lens and the bare fiber to the focusing plane and beam width. The freedom of modifying the working distance and lateral resolution is shown. This is achieved by changing the gap distance between the single-mode fiber and the microball lens within the packaged surgical needle catheter without using an additional beam expander ...
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    241-264 of 464 « 1 2 ... 8 9 10 11 12 13 14 ... 18 19 20 »
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