1. Articles in category: Probes

    1-24 of 616 1 2 3 4 ... 24 25 26 »
    1. Stick-slip nonuniform rotation distortion correction in distal scanning optical coherence tomography catheters

      Stick-slip nonuniform rotation distortion correction in distal scanning optical coherence tomography catheters

      We present a robust and fiducial-marker-free algorithm that can identify and correct stick-slip distortion caused by nonuniform rotation (or beam scanning) in distally scanned catheters for endoscopic optical coherence tomography (OCT) images. This algorithm employs spatial frequency analysis to select and remove distortions. We demonstrate the feasibility of this algorithm on images acquired from ex vivo rat colon with a distally scanned DC motor-based endoscope. The proposed algorithm can be applied to general endoscopic OCT images for correcting nonuniform rotation distortion.

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    2. Fiber-Needle Swept-Source Optical Coherence Tomography for the Real-Time Visualization of the Transversus Abdominis Plane Block Procedure in a Swine Model

      Fiber-Needle Swept-Source Optical Coherence Tomography for the Real-Time Visualization of the Transversus Abdominis Plane Block Procedure in a Swine Model

      Background: Fascia blocks (eg, the transversus abdominis plane [TAP] block) target the intermuscular fascia layers. Ultrasound techniques have allowed peripheral blocks to be performed with accuracy and safety, however, with limitations. Optical coherence tomography (OCT) is based on low-coherence interferometry. In this study, we examined the ability of OCT to identify the TAP. Methods: A swept-source OCT probe was placed in a 17-gauge needle to obtain imaging. The needle was inserted within 2 different angle ranges (0°-30° and 30°-60°) on a slice of pork belly to assess imaging characteristics. A series of real-time OCT imaging of the muscle ...

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    3. Feasibility of combined optical coherence tomography and autofluorescence imaging for visualization of needle biopsy placement

      Feasibility of combined optical coherence tomography and autofluorescence imaging for visualization of needle biopsy placement

      Significance: Diagnosis of suspicious lung nodules requires precise collection of relevant biopsies for histopathological analysis. Using optical coherence tomography and autofluorescence imaging (OCT-AFI) to improve diagnostic yield in parts of the lung inaccessible to larger imaging methods may allow for reducing complications related to the alternative of computed tomography-guided biopsy. Aim: Feasibility of OCT-AFI combined with a commercially available lung biopsy needle was demonstrated for visualization of needle puncture sites in airways with diameters as small as 1.9 mm. Approach: A miniaturized OCT-AFI imaging stylet was developed to be inserted through an 18G biopsy needle. We present design considerations ...

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    4. Optical probe

      Optical probe

      An optical probe includes an optical source that generates an optical beam that propagates from a proximal end to a distal end of an optical fiber that imparts a transformation of a spatial profile of the optical beam. An optical control device imparts a compensating spatial profile on the optical beam that at least partially compensates for the transformation of the spatial profile of the optical beam imparted by the optical fiber in response to a control signal from a signal processor. A distal optical source generates a calibration light that propagates through the one or more optical waveguides from ...

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      Mentions: Eric A. Swanson
    5. Miniaturized all fiber probe for optical coherence tomography and pH detection of biological tissue

      Miniaturized all fiber probe for optical coherence tomography and pH detection of biological tissue

      We present a novel all‐fiber probe with 710‐μm outside diameter for combined optical coherence tomography and pH detection. In cancer surgery, a significant challenge is how to completely remove the malignant tumor without cutting too much normal tissue. The difference between cancer tissue and normal tissue not only lies in morphology and structure but also in tissue pH, where malignant tissue has a lower pH. This dual‐modality probe combined optical coherence tomography and pH detection of biological tissue, is expected to determine whether the tissue is cancerous quickly and accuporcine ely. The probe utilizes a typical three ...

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    6. Feasibility Study to Assess a Trans-nasal Intestinal Potential Difference Probe

      Feasibility Study to Assess a Trans-nasal Intestinal Potential Difference Probe

      Increased gastrointestinal (GI) permeability is associated to several GI conditions that affect millions of people worldwide. Healthy intestinal walls limit only specific molecules to cross into the body. "Leaky gut" is a condition of unregulated and increased gut permeability that allows unwanted antigens, pathogens and microbial toxins into the bloodstream(1). This in turn leads to a subsequent immune response that includes the production of inflammatory mediators. Leaky gut is a key feature in celiac disease, Crohn's disease, inflammatory bowel disease (IBD), and environmental enteropathy and have been associated with systemic diseases including type 1 diabetes, autoimmune hepatitis, and ...

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    7. Tethered capsule en face optical coherence tomography for imaging Barrett’s oesophagus in unsedated patients

      Tethered capsule en face optical coherence tomography for imaging Barrett’s oesophagus in unsedated patients

      Objective Barrett’s oesophagus (BE) screening outside the endoscopy suite can identify patients for surveillance and reduce mortality. Tethered capsule optical coherence tomography (OCT) can volumetrically image oesophageal mucosa in unsedated patients and detect features of BE. We investigated ultrahigh-speed tethered capsule swept-source OCT (SS-OCT), improved device design, developed procedural techniques and measured capsule contact, longitudinal pullback non-uniformity and patient toleration. Design OCT was performed in 16 patients prior to endoscopic surveillance/treatment. Unsedated patients swallowed the capsule with sips of water and the tether was pulled back to image the oesophagus. SS-OCT at 1 000 000 A-scans/s enabled ...

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    8. System and method for detecting optical probe connection

      System and method for detecting optical probe connection

      A catheter system includes an electronic console; a catheter having a proximal end attachable to the console and a distal end configured to house therein an optical probe; an optical fiber configured to transmit from the console to the optical probe excitation radiation of a first wavelength, and configured to return to the console an optical response signal having a second wavelength longer than the first wavelength; a detector configured to detect intensity of the optical response signal; and a processor configured to determine, based on the detected intensity of the optical response signal, whether the catheter is properly connected ...

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    9. System and method for facilitating manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device

      System and method for facilitating manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device

      According to exemplary embodiments of the present disclosure, apparatus, device and method can be provided which can provide imaging of biological tissues, e.g., luminal organs in vivo, using optical techniques in an automatic or semiautomatic manner. The exemplary apparatus, device and method can utilize a tethered capsule catheter with a mechanism for manual, semi-automatic or automatic traversing in the luminal organ with a controlled velocity and/or image quality. The exemplary apparatus can include feedback information about tension applied to the catheter during its movement that can be used to adjust velocity and assure patient comfort and safety for ...

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    10. Chronic total occlusion crossing devices with imaging

      Chronic total occlusion crossing devices with imaging

      An imaging device includes a hollow flexible shaft having a central longitudinal axis and an imaging window therein. An optical fiber extends within the hollow flexible shaft substantially along the central axis. A distal tip of the optical fiber is attached to the hollow flexible shaft and aligned with the imaging window so as to transfer an optical coherence tomography signal through the imaging window. A handle is attached to the hollow flexible shaft configured rotate the hollow flexible shaft at speeds of greater than 1,000 rpm.

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      Mentions: Avinger
    11. Needle tip force estimation by deep learning from raw spectral OCT data

      Needle tip force estimation by deep learning from raw spectral OCT data

      Purpose Needle placement is a challenging problem for applications such as biopsy or brachytherapy. Tip force sensing can provide valuable feedback for needle navigation inside the tissue. For this purpose, fiber-optical sensors can be directly integrated into the needle tip. Optical coherence tomography (OCT) can be used to image tissue. Here, we study how to calibrate OCT to sense forces, e.g., during robotic needle placement. Methods We investigate whether using raw spectral OCT data without a typical image reconstruction can improve a deep learning-based calibration between optical signal and forces. For this purpose, we consider three different needles with ...

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    12. Ultrathin monolithic 3D printed optical coherence tomography endoscopy for preclinical and clinical use

      Ultrathin monolithic 3D printed optical coherence tomography endoscopy for preclinical and clinical use

      Preclinical and clinical diagnostics increasingly rely on techniques to visualize internal organs at high resolution via endoscopes. Miniaturized endoscopic probes are necessary for imaging small luminal or delicate organs without causing trauma to tissue. However, current fabrication methods limit the imaging performance of highly miniaturized probes, restricting their widespread application. To overcome this limitation, we developed a novel ultrathin probe fabrication technique that utilizes 3D microprinting to reliably create side-facing freeform micro-optics (<130 µm diameter) on single-mode fibers. Using this technique, we built a fully functional ultrathin aberration-corrected optical coherence tomography probe. This is the smallest freeform 3D imaging probe ...

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    13. Device and system for doppler optical coherence tomography (OCT) of the human middle ear

      Device and system for doppler optical coherence tomography (OCT) of the human middle ear

      A device for Doppler optical coherence tomography (Doppler OCT), preferably of the human middle ear, is proposed. The device has an endoscope unit for at least partial insertion into the auditory canal. A sound source, a sound receiver, and OCT optics are integrated in the endoscope unit.

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    14. An imaging analysis and reconstruction method for multiple-micro-electro-mechanical system mirrors-based off-centre scanning optical coherence tomography probe

      An imaging analysis and reconstruction method for multiple-micro-electro-mechanical system mirrors-based off-centre scanning optical coherence tomography probe

      An endoscopic optical coherence tomography (OCT) probe that can perform full circumferential scans using a circular array of six micro-electro-mechanical system (MEMS) mirrors has been developed. Inside the OCT probe, each of the six MEMS mirrors forms an independent scanning unit; circumferential OCT images are acquired by off-centre scanning and combining the image data from the individual multiple scanning units. Here, an imaging analysis and reconstruction (IAR) method is proposed to construct endoscopic OCT volumetric images from the multiple individual MEMS scanning unit. Imaging procedures of six-MEMS mirrors-based, eight-MEMS mirrors-based and twelve-MEMS mirrors-based OCT probes have been analyzed theoretically. All ...

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    15. Flexible endoscopic micro-optical coherence tomography for three-dimensional imaging of the arterial microstructure

      Flexible endoscopic micro-optical coherence tomography for three-dimensional imaging of the arterial microstructure

      Micro-optical coherence tomography (µOCT) is a novel imaging approach enabling visualization of the microstructures of biological tissues at a cellular or sub-cellular level. However, it has been challenging to develop a miniaturized flexible endoscopic µOCT probe allowing helical luminal scanning. In this study, we built a flexible endoscopic µOCT probe with an outer diameter of 1.2 mm, which acquires three-dimensional images of the arterial microstructures via helical scanning with an axial and lateral resolutions of 1.83 µm and 3.38 µm in air, respectively. Furthermore, the depth of focus of the µOCT imaging probe was extended two-fold using ...

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    16. Device and methods for color corrected OCT imaging endoscope/catheter to achieve high-resolution

      Device and methods for color corrected OCT imaging endoscope/catheter to achieve high-resolution

      The present invention is directed to an achromatic endoscope which employs a diffractive microlens. Along with a broadband rotary joint and a custom 800 nm SD-OCT system, ultrahigh-resolution 3D volumetric imaging over a large area becomes possible. The diffractive microlens can be used directly with a GRIN lens, making the endoscope design simpler and cost effective. Preliminary ex vivo 3D intraluminal imaging was performed with the endoscope in conjunction with a home-built broadband rotary joint and a spectral-domain OCT system, demonstrating the performance of the diffractive endoscope. Considering the miniature OCT imaging probe is the required component for using the ...

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    17. Intravascular imaging and guide catheter detection methods and systems

      Intravascular imaging and guide catheter detection methods and systems

      In part, the disclosure relates to computer-based methods, devices, and systems suitable for detecting a delivery catheter using intravascular data. In one embodiment, the delivery catheter is used to position the intravascular data collection probe. The probe can collect data suitable for generating one or more representations of a blood vessel with respect to which the delivery catheter can be detected.

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      Mentions: Abbot
    18. Imaging system includes imaging probe and delivery devices

      Imaging system includes imaging probe and delivery devices

      An imaging system is provided comprising an imaging probe and at least one delivery device. The imaging probe comprises an elongate shaft, a rotatable optical core and an optical assembly. The elongate shaft comprises a proximal end, a distal portion, and a lumen extending between the proximal end and the distal portion. The rotatable optical core is positioned within the lumen of the elongate shaft and comprises a proximal end and a distal end. The rotatable optical core is configured to optically and mechanically connect with an interface unit. The optical assembly is positioned in the elongate shaft distal portion ...

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    19. Low-cost, ultracompact handheld optical coherence tomography probe for in vivo oral maxillofacial tissue imaging

      Low-cost, ultracompact handheld optical coherence tomography probe for in vivo oral maxillofacial tissue imaging

      Significance: Optical coherence tomography (OCT) has proven useful for detecting various oral maxillofacial abnormalities. To apply it to clinical applications including biopsy guidance and routine screening, a handheld imaging probe is indispensable. OCT probes reported for oral maxillofacial imaging were either based on a bulky galvanometric mirror pair (not compact or long enough) or a distal-end microelectromechanical systems (MEMS) scanner (raised safety concerns), or adapted from fiber-optic catheters (ill-suited for oral cavity geometry). Aim: To develop a handheld probe featuring great compactness and excellent maneuverability for oral maxillofacial tissue imaging. Approach: A dual-axis MEMS scanner was deployed at the proximal ...

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    20. Miniaturized precalibration-based Lissajous scanning fiber probe for high speed endoscopic optical coherence tomography

      Miniaturized precalibration-based Lissajous scanning fiber probe for high speed endoscopic optical coherence tomography

      We present a miniaturized precalibration-based forward-viewing Lissajous scanning fiber probe for high speed endoscopic optical coherence tomography (OCT). The probe is based on an asymmetric fiber cantilever driven by the piezoelectric bender to realize two-dimensional (2D) Lissajous scanning. The stability and repeatability of the Lissajous scanning trajectory of the probe is tested by a position sensitive detector (PSD)-based position calibration setup. The two orthogonal resonant frequencies of the cantilever are measured to be 167.2 and 121 Hz. A 25 µm focal spot is formed at the working distance of 5 mm by the graded-index (GRIN) lens, and the ...

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    21. Real-time Lissajous imaging with a low-voltage 2-axis MEMS scanner based on electrothermal actuation

      Real-time Lissajous imaging with a low-voltage 2-axis MEMS scanner based on electrothermal actuation

      Laser scanning based on Micro-Electro-Mechanical Systems (MEMS) scanners has become very attractive for biomedical endoscopic imaging, such as confocal microscopy or Optical Coherence Tomography (OCT). These scanners are required to be fast to achieve real-time image reconstruction while working at low actuation voltage to comply with medical standards. In this context, we report a 2-axis Micro-Electro-Mechanical Systems (MEMS) electrothermal micro-scannercapable of imaging large fields of view at high frame rates, e.g. from 10 to 80 frames per second. For this purpose, Lissajous scan parameters are chosen to provide the optimal image quality within the scanner capabilities and the sampling ...

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    22. NTU scientists develop handheld, high-resolution medical imaging device

      NTU scientists develop handheld, high-resolution medical imaging device

      NTU scientists develop handheld, high-resolution medical imaging device with potential for bedside scanning Scientists at Nanyang Technological University, Singapore (NTU Singapore) have developed the prototype of a handheld medical imaging device that can produce images down to resolutions of 1 to 2 micrometres. This is detailed enough to spot the first signs of tumours in specific cells and is about 100 times higher resolution than what X-Ray, computed tomography (CT) and Magnetic Resonance Imaging (MRI) machines can provide. The technology behind the device is a result of six years of optical imaging research and was jointly developed by a team ...

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    23. Optical coherence tomography system with dual optical coherence tomography probes

      Optical coherence tomography system with dual optical coherence tomography probes

      An optical coherence tomography (OCT) system with dual optical coherence tomography probes is provided comprising: an optical scope comprising a distal end; a first OCT probe; and, a second OCT probe, each of the first OCT probe and the second OCT probe mechanically attached to the optical scope, the first OCT probe and the second OCT probe being substantially paraxial and configured to focus on a same scanning area, the optical scope configured to optically image the same scanning area using the distal end, the first OCT probe having a higher resolution than the second OCT probe.

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    24. Side-viewing endoscopic imaging probe for swept source optical coherence tomography

      Side-viewing endoscopic imaging probe for swept source optical coherence tomography

      Endoscopic optical coherence tomography (OCT) has many promising applications in the fields of medical research and clinical diagnosis. In this letter, we present a side-viewing endoscopic OCT probe based on a gradient index (GRIN) lens with an air gap. By adjusting the length of the air gap the optical performance of the probe can be flexibly tuned. The quantitative relationships between the optical performance parameters of the probe and its structural parameters are theoretically analyzed by using the ABCD beam transfer matrix theory. The developed probe has a maximum diameter of 1.4 mm and a rigid length of 11 ...

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    1-24 of 616 1 2 3 4 ... 24 25 26 »
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