1. Articles from Shuwen Wei

    1-4 of 4
    1. Stabilizing the phase of swept-source optical coherence tomography by a wrapped Gaussian mixture model

      Stabilizing the phase of swept-source optical coherence tomography by a wrapped Gaussian mixture model

      The phase of an optical coherence tomography (OCT) signal carries critical information about particle micro-displacements. However, swept-source OCT (SSOCT) suffers from phase instability problems due to trigger jitters from the swept source. In this Letter, a wrapped Gaussian mixture model (WGMM) is proposed to stabilize the phase of SSOCT systems. A closed-form iteration solution of the WGMM is derived using the expectation-maximization algorithm. Necessary approximations are made for real-time graphic processing unit implementation. The performance of the proposed method is demonstrated through ex vivo, in vivo, and flow phantom experiments. The results show the robustness of the method in different ...

      Read Full Article
    2. Optical flow optical coherence tomography for determining accurate velocity fields

      Optical flow optical coherence tomography for determining accurate velocity fields

      Determining micron-scale fluid flow velocities using optical coherence tomography (OCT) is important in both biomedical research and clinical diagnosis. Numerous methods have been explored to quantify the flow information, which can be divided into either phase-based or amplitude-based methods. However, phase-based methods, such as Doppler methods, are less sensitive to transverse velocity components and suffer from wrapped phase and phase instability problems for axial velocity components. On the other hand, amplitude-based methods, such as speckle variance OCT, correlation mapping OCT and split-spectrum amplitude-decorrelation angiography, focus more on segmenting flow areas than quantifying flow velocities. In this paper, we propose optical ...

      Read Full Article
    3. Selective retina therapy monitoring by speckle variance optical coherence tomography for dosimetry control

      Selective retina therapy monitoring by speckle variance optical coherence tomography for dosimetry control

      Significance: Selective retina therapy (SRT) selectively targets the retinal pigment epithelium (RPE) and reduces negative side effects by avoiding thermal damages of the adjacent photoreceptors, the neural retina, and the choroid. However, the selection of proper laser energy for the SRT is challenging because of ophthalmoscopically invisible lesions in the RPE and different melanin concentrations among patients or even regions within an eye. Aim: We propose and demonstrate SRT monitoring based on speckle variance optical coherence tomography (svOCT) for dosimetry control. Approach: M-scans, time-resolved sequence of A-scans, of ex vivo bovine retina irradiated by 1.7-μs duration laser pulses ...

      Read Full Article
    4. Intraoperative Speckle Variance Optical Coherence Tomography for Tissue Temperature Monitoring During Cutaneous Laser Therapy

      Intraoperative Speckle Variance Optical Coherence Tomography for Tissue Temperature Monitoring During Cutaneous Laser Therapy

      Background: Tissue temperature monitoring during cutaneous laser therapy can lead to safer and more effective treatments. In this study, we investigate the use of speckle variance optical coherence tomography (svOCT) to monitor real-time temperature changes in the excised human skin tissue sample during laser irradiation. Methods: To accomplish this, we combined the pulse laser system with a reference-based svOCT system. To calibrate the svOCT, the ex-vivo human skin samples from three individuals with tissues collected from the arm, face, and back were heated with 1-degree increments. Additionally, linear regression was used to extract and evaluate the linear relationship between the ...

      Read Full Article
    1-4 of 4
  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
  2. Topics in the News

    1. (4 articles) Johns Hopkins University
  3. Popular Articles

  4. Picture Gallery

    Intraoperative Speckle Variance Optical Coherence Tomography for Tissue Temperature Monitoring During Cutaneous Laser Therapy Selective retina therapy monitoring by speckle variance optical coherence tomography for dosimetry control Optical flow optical coherence tomography for determining accurate velocity fields Stabilizing the phase of swept-source optical coherence tomography by a wrapped Gaussian mixture model New insights from non-invasive imaging: from prospection of skin photodamages to training with mobile application Short-sighted woman assumes debilitating headaches mean she needs new glasses but discovers she has multiple sclerosis Shedding light on the impact of microplastics on lentil seedling growth Comparison of radial peripapillary capillary density results of individuals with and without Helicobacter pylori infection Ai, Oct Operate in Tandem to Detect Plaque Erosion in the Heart Noninvasive, in vivo, characterization of cutaneous metastases using a novel multimodal RCM-OCT imaging device: A case-series Mimickers of punctate inner retinal toxoplasmosis on optical coherence tomography Measuring collagen injury depth for burn severity determination using polarization sensitive optical coherence tomography