1. 1-18 of 18
    1. Progress of Intravascular Optical Coherence Tomography Image Technology and Vascular Three-Dimensional Reconstruction

      Progress of Intravascular Optical Coherence Tomography Image Technology and Vascular Three-Dimensional Reconstruction

      Intravascular optical coherence tomography (IV-OCT) is a new intervention imaging technology for the diagnosis of coronary heart disease. Because of its high-resolution and non-invasive characteristics, it is widely used in clinical medicine. It has a revolutionary impact on coronary artery disease diagnosis, prognosis and treatment decisions. This paper studied this hot topic, gave the basic concepts of intravascular OCT image sequences. In accordance with current development studies, the key technology for three-dimensional reconstruction of the coronary vascular system is proposed and analyzed. On this basis, we proposed future research directions on IV-OCT vascular three-dimensional reconstruction, including clinical trial frequency domain ...

      Read Full Article
    2. Material Defects in Ceramic Crowns Identification by Optical Coherence Tomography and MicroCT

      Material Defects in Ceramic Crowns Identification by Optical Coherence Tomography and MicroCT

      Full ceramic crowns are considered revolutionary in developing the concept of aesthetic dentistry. Appreciate their aesthetic appearance particularly raise the cost prices, they do not ensure the risk of fractures and cracks which sometimes face the clinician after their insertion directly into the mouth. As a result of the fracture may occur between disputes team dentist-dental technician. The purpose of this study was to identify flaws of material included in the pottery table analyzing the full ceramic crowns using non-invasive technologies. As materials we use 25 full ceramic crowns (e. max, IVOCLAR) obtained through the technology of pressing were used ...

      Read Full Article
    3. Investigation of Biodegradable Composite Coated Magnesium Alloy Using Optical Coherence Tomography

      Investigation of Biodegradable Composite Coated Magnesium Alloy Using Optical Coherence Tomography

      Optical coherence tomography (OCT) was used to characterize poly (lactic-co-glycolic acid) (PLGA) and nanophase hydroxyapatite (nHA) / PLGA coatings on magnesium (Mg) substrates before and after immersion in revised simulated body fluid (rSBF) under standard cell culture conditions. The OCT images clearly showed: the surface of the coatings, the metallic surface underneath the coatings, the presence of a dispersed phase within the polymer matrix, and defects and structural changes to the coatings. This study demonstrated the potential utility of OCT for performing quality assurance tests and for tracking the physical effects of degradation upon biomedical implants due to its ability to ...

      Read Full Article
    4. Non-Contact Creep Measurement Based on Fourier Domain Optical Coherence Tomography

      Non-Contact Creep Measurement Based on Fourier Domain Optical Coherence Tomography

      A non-contact Fourier-domain optical coherence creep tomography (OCCT) is developed and employed in real-time non-contact creep measurement. Experiments on thermal deformation were carried out by using the self-developed OCCT to measure a high-temperature structure. In the OCCT system, a high-performance spectrometer, and a thermal light are, respectively, employed as the detector and the light source. Due to the broadband of the spectrometer and light source, the system provided high robust performance with an excellent deformation measurement resolution of sub-millimeter scale. Due to the energy leakage effect of FFT, a spectrum correction technique was employed to enhance the resolution of the ...

      Read Full Article
    5. Optical Imaging of Oral Squamous Cell Carcinoma Using Optical Coherence Tomography and Micro CT

      Optical Imaging of Oral Squamous Cell Carcinoma Using Optical Coherence Tomography and Micro CT

      Oral squamous cell carcinoma (OSCC) constitutes 90% of oral cancer. Early detection is a cornerstone to improve survival and to reduce diagnostic delay. We propose optical coherence tomography (OCT), as a non-invasive diagnosis method. OCT represents a new high-resolution optical technique that permits 3D, real-time imaging of near surface abnormalities in complex tissues. In the present study half of the excisional biopsy was directed to the pathologist and the other half was assigned for OCT and Micro-CT investigation. For the OCT imaging it was used an OCT prototype (1300 nm), Synchrotron Radiation Micro-CT and histopathology validated the results. Areas of ...

      Read Full Article
    6. Pearl Thickness Measurements from Optical Coherence Tomography Images

      Pearl Thickness Measurements from Optical Coherence Tomography Images

      By measuring the thickness of the nacreous layer, pearl optical coherence tomography (OCT) images are now increasingly used in identification and characterization. An approach to automated thickness measurement of pearl OCT image has been reported in this paper. A Total Variational (TV) Model filter has been used to remove noise in images. After the image filtering, edges are detected by self-adaptive Canny operator. In the end we used circle fitting technologies to archive the goal of automated thickness measurement. The experimental results show this approach is accurate and adaptable.

      Read Full Article
    7. A Fast Algorithm for Automatic Detection of Anterior Chamber Angle Points and Measurement of Central Corneal Thickness for Anterior Chamber OCT Images

      A Fast Algorithm for Automatic Detection of Anterior Chamber Angle Points and Measurement of Central Corneal Thickness for Anterior Chamber OCT Images

      This paper proposed a fast algorithm to detect anterior chamber angle points and measure central corneal thickness for anterior chamber optical coherence tomography (OCT) images automatically. This algorithm uses biggest connected regions method to get the anterior chamber region, and detects the anterior chamber angle points (ACAPs) in this region firstly. Secondly, the algorithm uses ACAPs to obtain the real position of central cornea then measures the central corneal thickness of anterior chamber. The proposed algorithm was tested on 74 anterior chamber OCT images and provided accurate measurements in about 90 milliseconds.

      Read Full Article
    8. Research on Measurement System of Biological Tissue Parameters Based on Optical Coherence Tomography

      Research on Measurement System of Biological Tissue Parameters Based on Optical Coherence Tomography

      In order to measure the optical parameters of biological tissue accurately and non-invasive, the measurement system based on optical coherence tomography was analyzed and designed from two aspects of hardware and software. The refractive index was calibrated by standard refractive index solutions, experiments were preformed to obtain refractive index of tissue samples and scattering coefficient of Intralipid TM solution with different concentrations. Results show that the experimental values of refractive index agree with the standard values roughly and scattering coefficient linear relate with concentration in Intralipid TM solution. The measurement system designed in our experiment is accurate and reliable, simple ...

      Read Full Article
    9. A New Denoising Approach for Optical Coherence Tomography Image Based on the Total Variational Model

      A New Denoising Approach for Optical Coherence Tomography Image Based on the Total Variational Model

      The traditional total variational (TV) model performs well for most noise image. However, the method will lose some information and details for the image which has rich texture and tiny boundary. Therefore, according to the requirements of the OCT pearl image, a novel denoising approach based on the TV model is proposed in this paper. This method combined the adaptive image denoising model and the novel fidelity term. Numerical experiments show that the proposed method can remove the noise while preserving significant image details. At pearl OCT image the method achieves at least 0.1dB gain over other existing denoising ...

      Read Full Article
    10. Spectral-Domain Optical Coherence Tomography for Material Detection

      Spectral-Domain Optical Coherence Tomography for Material Detection

      Optical coherence tomography is a non-invasive cross-sectional imaging technology for inhomogeneous samples. Spectral-domain optical coherence tomography is introduced to measure film and Silicon dovetail groove in this paper. A novel method is used to deal with the interference spectrum to improve the quality of the two-dimensional cross-sectional image. The experimental result shows the microstructure of the two samples can be clearly seen as expected. From the visualized two-dimensional cross-sectional imaging, the film thickness and the dimension of the Silicon dovetail groove are obtained with this technique. It is experimentally demonstrated that this system is useful for imaging the microstructure of ...

      Read Full Article
    11. Assembled Singlemode and Graded Index Fibers Simulating Collimator for All Fiber Common-Path Optical Coherence Tomography

      Assembled Singlemode and Graded Index Fibers Simulating Collimator for All Fiber Common-Path Optical Coherence Tomography
      A single mode fiber assembled with a specified length graded index multimode fiber as a collimator, which is used in common-path optical coherence tomography (CPOCT) is described in this paper. Compared with conventional collimator lens, this assembled fibers structure possesses the advantages of small volume, easy to be fused or connected with other part of the CPOCT system. Furthermore, with this assembled structure an all fiber CPOCT system is constructed which has the potential to detect the internal bodily organs and tissues of human being. Numerical simulation and experiments are implemented to verify the effectiveness of this method.
      Read Full Article
    12. Mobile Optical Coherence Tomography Sensor for Surface Layers Testing

      Mobile Optical Coherence Tomography Sensor for Surface Layers Testing

      In the paper the new type of mobile sensor based on optical coherence tomography is presented. For increasing the measurement range the special dynamic focusing system which moves imaging plane during axial scanning process is used. Therefore developed system allows focusing on measured layer. Additionally, for image analysis the special type of CMOS matrix (called smart-pixel camera), synchronized with a reference mirror transducer, is applied. Due to hardware realization of a fringe contrast analysis simultaneously in each pixel with high frequency, the time of measurement decreases significantly. These advantages together with a compact design allow the sensor to be used ...

      Read Full Article
    13. Infrared Optical Path Adjustment Method for Common-Path Optical Coherence Tomography

      Infrared Optical Path Adjustment Method for Common-Path Optical Coherence Tomography

      A new, common-path, in-axis concentric beam-splitting Michelson interferometer is demonstrated for optical coherence tomography (OCT), which can be used to perform high-resolution cross-sectional in vivo and in situ imaging of biological tissues. A piece of glass tube with its inner diameter smaller than the beam-width of the collimated light is used to split the light into a reference and sample beam. In order to obtain the optimal spectral interferogram of this OCT system, an infrared optical path adjustment method was introduced in this paper

      Read Full Article
    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 ...

      Read Full Article
    15. 3-D Image Reconstruction in Optical Coherence Tomography Systems Based on VTK in OCT Systems

      3-D Image Reconstruction in Optical Coherence Tomography Systems Based on VTK in OCT Systems
      According to a ray casting algorithm,a method of 3-D image reconstruction in optical coherence tomography systems is presented. Volume data formed by a series of cross-sectional 2-D images are obtained experimentally in a traditional OCT system and a full-field OCT system. Using the ray casting algorithm, 3-D images have been reconstructed from these data base on VTK. The 3-D images rendering apparently reflect the corresponding details of samples.
      Read Full Article
    16. Resolution Improvement with Two-Dimensional Digital Focusing Method in Optical Coherence Tomography

      Resolution Improvement with Two-Dimensional Digital Focusing Method in Optical Coherence Tomography

      This paper presents a two-dimensional (2D) digital focusing method to alleviate the compromise between the resolution and depth of field (DOF) in spectral domain optical coherence tomography (SDOCT). A scalar diffraction model is developed to simulate the wave propagation process from out-of-focus scatterers and the inverse scattering problem is solved. The wavenumber domain algorithm is applied to improve the transverse resolution, and the matched filter to improve the axial resolution. Image reconstruction with spatially invariant resolution can be achieved. The 2D imaging experimental results of fresh pig liver prove the effectiveness of the proposed method.

      Read Full Article
      Mentions: Yi Wang
    17. High Speed Spectral Optical Coherence Tomography for Imaging Biological Tissue In Vivo

      High Speed Spectral Optical Coherence Tomography for Imaging Biological Tissue In Vivo
      A high speed spectral optical coherence tomography (SOCT) system was demonstrated. An achievable scanning speed of 92k line/sec has been reached and it can acquire 3-dimensional data sets in ~3 second. The axial resolution of ~13μm and lateral resolution of ~16μm have been realized. The system is capable of a theoretical depth measurement 3.2mm in air. We also measured the sensitivity performance corresponding to difference depth and it demonstrated that our system can differentiate signal form noise at 3mm pathlength difference. Using the system, human palm skin was measured in vivo.
      Read Full Article
    18. Experimental Investigation into High Speed FD-OCT Imaging Based on Orthogonally Polarized Light

      Experimental Investigation into High Speed FD-OCT Imaging Based on Orthogonally Polarized Light
      A phase shifting method based on orthogonal polarized light is proposed over complex Fourier domain optical coherence tomography (FD-OCT) to enhance the speed of OCT image scanning and to resist the environmental disturbance such as vibration. In the proposed approach, one simple wave plates (a quarter-wave plate ) are inserted into the system with appropriate rotational angles, the one interference data on orthogonal polarized directions will then manipulate with π/2 phase-shifting algorithm to reduce the scanning frequency. In other words, the proposed approach enables one-shot and full-range FD-OCT
      Read Full Article
    1-18 of 18
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks