A polarity thresholding algorithm that has recently been developed for split-spectrum processing for ultrasonic coherent noise reduction is theoretically analyzed to evaluate its performance. The probability density function (PDF) of the output of the algorithm is derived and used to calculate the theoretical signal-to-noise ratio (SNR) enhancement and the receiver operating characteristics. The performance limits of the algorithm are also established. Some experimental results of SNR enhancement obtained with the polarity thresholding algorithm are presented.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1109/58.16976 | DOI Listing |
Biomed Opt Express
February 2023
Department of Biomedical Science, College of Medicine, Korea University, Seoul 02841, Republic of Korea.
Biomedical researchers use optical coherence microscopy (OCM) for its high resolution in real-time label-free tomographic imaging. However, OCM lacks bioactivity-related functional contrast. We developed an OCM system that can measure changes in intracellular motility (indicating cellular process states) via pixel-wise calculations of intensity fluctuations from metabolic activity of intracellular components.
View Article and Find Full Text PDFAnn N Y Acad Sci
August 2021
Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
We trained a deep learning algorithm to use skin optical coherence tomography (OCT) angiograms to differentiate between healthy and type 2 diabetic mice. OCT angiograms were acquired with a custom-built OCT system based on an akinetic swept laser at 1322 nm with a lateral resolution of ∼13 μm and using split-spectrum amplitude decorrelation. Our data set consisted of 24 stitched angiograms of the full ear, with a size of approximately 8.
View Article and Find Full Text PDFDetermining 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.
View Article and Find Full Text PDFSensors (Basel)
August 2020
Department of Civil Engineering, Brunel University London, Kingston Lane, Uxbridge UB8 3PH, UK.
Ultrasonic guided wave (UGW) testing is widely applied in numerous industry areas for the examination of pipelines where structural integrity is of concern. Guided wave testing is capable of inspecting long lengths of pipes from a single tool location using some arrays of transducers positioned around the pipe. Due to dispersive propagation and the multimodal behavior of UGW, the received signal is usually degraded and noisy, that reduce the inspection range and sensitivity to small defects.
View Article and Find Full Text PDFTransl Vis Sci Technol
February 2020
Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, Western Australia, Australia.
Purpose: To determine the impact of an AngioVue software upgrade on total retinal thickness (RT) and inner retinal vessel density (VD) measurements derived from optical coherence tomography angiography (OCTA).
Methods: Optovue OCTA images (3 × 3 mm) from 126 individuals (105 healthy eyes and 72 eyes with retinal disease) were acquired before an upgrade of the AngioVue software, which resulted in an inward shift of the outer boundary of the inner retinal vessels and improved Bruch's membrane segmentation. Total RT and inner retinal VD values were extracted before and after the software upgrade for comparison.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!