Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Downsampling01:20

Downsampling

816
When considering a sampled sequence with zero values between sampling instants, one can replace it by taking every N-th value of the sequence. At these integer multiples of N, the original and sampled sequences coincide. This process, known as decimation, involves extracting every N-th sample from a sequence, thereby creating a more efficient sequence.
The Fourier transform of the decimated sequence reveals a combination of scaled and shifted versions of the original spectrum. This...
816
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)01:20

¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

1.9K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.9K
Linear Approximation in Frequency Domain01:26

Linear Approximation in Frequency Domain

447
Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar.
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
447
Upsampling01:22

Upsampling

715
Managing signal sampling rates is essential in digital signal processing to maintain signal integrity. A decimated signal, characterized by a reduced frequency range due to its lower sampling rate, can be upsampled by inserting zeros between each sample. This upsampling process expands the original spectrum and introduces repeated spectral replicas at intervals dictated by the new Nyquist frequency. To refine this zero-inserted sequence, it is passed through a lowpass filter with a cutoff...
715
NMR Spectroscopy: Chemical Shift Overview01:15

NMR Spectroscopy: Chemical Shift Overview

4.1K
The position of the absorption signal of a sample is reported relative to the position of the signal of tetramethylsilane (TMS), which is added as an internal reference while recording spectra. The difference between the absorption frequencies of the sample and TMS (in Hz) is divided by the spectrometer operating frequency (in MHz) to obtain a dimensionless quantity called the chemical shift. It is reported on the δ (delta) scale and expressed in parts per million.
For instance, the proton...
4.1K
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations01:08

IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations

2.3K
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
2.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Segmentation-guided photon pooling enables robust single-cell analysis and fast fluorescence lifetime imaging microscopy.

Journal of biomedical optics·2026
Same author

Lagrangian deformation tracking for strain imaging.

Progress in biomedical engineering (Bristol, England)·2026
Same author

FLIM Playground: An interactive, end-to-end graphical user interface for analyzing single cells with fluorescence lifetime imaging microscopy.

Cell reports methods·2026
Same author

Geometry aware neural radiance fields for freehand ultrasound reconstruction.

Biomedical physics & engineering express·2026
Same author

3D Freehand Ultrasound Reconstruction of the Carotid Artery.

Ultrasound in medicine & biology·2026
Same author

Introducing ARONG, A 3D Reconstruction Method for Highly Deformed Histology.

Journal of imaging informatics in medicine·2026
Same journal

Theoretical Foundations of the Echo Envelope Statistical Modeling: A Tutorial.

IEEE transactions on ultrasonics, ferroelectrics, and frequency control·2025
Same journal

Practical Demonstrations of FR3-Band Thin-Film Lithium Niobate Acoustic Filter Design.

IEEE transactions on ultrasonics, ferroelectrics, and frequency control·2025
Same journal

Real-Time Heterogeneous Helical Wave Spectrum Method for Transabdominal Passive Acoustic Mapping.

IEEE transactions on ultrasonics, ferroelectrics, and frequency control·2025
Same journal

Cascaded Plane Wave Ultrasound Velocity Vector Imaging: In Vivo Feasibility in Carotid Arteries.

IEEE transactions on ultrasonics, ferroelectrics, and frequency control·2025
Same journal

Quantitative Acoustic Attenuation Scanning Using a Phase-Insensitive Ultrasound Computed Tomography System.

IEEE transactions on ultrasonics, ferroelectrics, and frequency control·2025
Same journal

FPGA-Accelerated CNN Reconstruction for Low-Power Sparse-Array Ultrasound Imaging.

IEEE transactions on ultrasonics, ferroelectrics, and frequency control·2025
See all related articles

Related Experiment Video

Updated: Apr 12, 2026

ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis
07:11

ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis

Published on: August 19, 2021

3.1K

Performance evaluation of the spectral centroid downshift method for attenuation estimation.

Kayvan Samimi, Tomy Varghese

    IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
    |May 13, 2015
    PubMed
    Summary
    This summary is machine-generated.

    This study analyzes the spectral centroid downshift (CDS) method for estimating ultrasonic attenuation in tissues. A new model predicts CDS method performance, improving accuracy for tissue characterization.

    More Related Videos

    High Speed Sub-GHz Spectrometer for Brillouin Scattering Analysis
    13:31

    High Speed Sub-GHz Spectrometer for Brillouin Scattering Analysis

    Published on: December 22, 2015

    15.9K
    Split Point Analysis and Uncertainty Quantification of Thermal-Optical Organic/Elemental Carbon Measurements
    10:22

    Split Point Analysis and Uncertainty Quantification of Thermal-Optical Organic/Elemental Carbon Measurements

    Published on: September 7, 2019

    8.9K

    Related Experiment Videos

    Last Updated: Apr 12, 2026

    ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis
    07:11

    ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis

    Published on: August 19, 2021

    3.1K
    High Speed Sub-GHz Spectrometer for Brillouin Scattering Analysis
    13:31

    High Speed Sub-GHz Spectrometer for Brillouin Scattering Analysis

    Published on: December 22, 2015

    15.9K
    Split Point Analysis and Uncertainty Quantification of Thermal-Optical Organic/Elemental Carbon Measurements
    10:22

    Split Point Analysis and Uncertainty Quantification of Thermal-Optical Organic/Elemental Carbon Measurements

    Published on: September 7, 2019

    8.9K

    Area of Science:

    • Medical Imaging
    • Biomedical Engineering
    • Acoustics

    Background:

    • Frequency-dependent ultrasonic attenuation is crucial for quantitative ultrasound and tissue characterization.
    • The spectral centroid downshift (CDS) method is a common technique for estimating attenuation.
    • Understanding CDS method performance is essential for accurate tissue differentiation.

    Purpose of the Study:

    • To statistically analyze the performance of the spectral centroid downshift (CDS) method for ultrasonic attenuation estimation.
    • To develop and validate a parametric model for predicting CDS method accuracy under various conditions.
    • To compare theoretical predictions with experimental results for attenuation estimation variance.

    Main Methods:

    • Developed a parametric model for the signal power spectrum, including Gaussian spectral profile, attenuation, windowing, and electronic noise.
    • Calculated spectral moments to estimate second-order centroid statistics.
    • Derived a theoretical expression for the variance of the maximum likelihood estimator of the attenuation coefficient.
    • Compared theoretical predictions with experimental variances using simulated and phantom data across a range of scan parameters (SNR, pulse bandwidth, center frequency, window length).

    Main Results:

    • The developed model accurately predicts the variance of attenuation estimation using the CDS method.
    • Theoretical predictions showed acceptable agreement with experimentally estimated variances.
    • Observed differences were smaller than 0.05 dB/cm/MHz across investigated parameter ranges.
    • The model successfully predicts achievable attenuation estimation variance based on scan parameters.

    Conclusions:

    • The validated parametric model provides a tool for predicting the performance of the CDS method for ultrasonic attenuation estimation.
    • This model aids in optimizing scan parameters to achieve the best attenuation estimation variance.
    • The findings contribute to more accurate quantitative ultrasound for tissue characterization.