相关实验视频
Updated: Jul 24, 2025

05:57
Blood Flow Imaging with Ultrafast Doppler
Published on: October 14, 2020
7.7K
简化和加速实施SVD用于过超高速功率多普勒图像
Baptiste Pialot1, Lionel Augeul2, Lorena Petrusca1
1Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, CREATIS UMR 5220, U1294, F-69621, Lyon, France.
Ultrasonics
|July 7, 2023
概括
一个新的算法,功率奇数值分解 (pSVD),通过简化噪声过,显著加快了超快功率多普勒 (UPD) 成像. 这一进步使得先进的微血管成像更容易获得临床使用.
科学领域:
- 超声波成像 超声波成像
- 医学诊断 医学诊断 医学诊断
- 生物医学工程 生物医学工程
背景情况:
- 超快速功率多普勒 (UPD) 对于微血管疾病的诊断至关重要.
- 单值分解 (SVD) 是 UPD 中的一个关键过器,但在计算上是密集和复杂的.
- 目前的SVD限制阻碍了高效的UPD算法的开发.
研究的目的:
- 引入功率SVD (pSVD),这是UPD的简化和加速算法.
- 解决UPD中传统SVD的计算负担和复杂性.
- 提高UPD基于SVD的过的速度和特异性.
主要方法:
- pSVD利用了SVD在UPD图像中的独特数学特性.
- 它可以从时间单一向量直接计算与血液相关的SVD组件.
- 性能在体外和体内被评估,与SVD和随机SVD (rSVD) 相比.
主要成果:
- pSVD 在体内将SVD运行时间缩短了5-12倍,而不会影响图像质量.
- 与rSVD相比,psVD提供了可比或更快的计算 (高达3倍).
- pSVD为隔离组织子空间提供了额外的估计器.
结论:
- pSVD是临床UPD实施的一个有价值的工具.
- 该算法简化和加速了用于超声波成像的SVD.
- 它增强了UPD用于诊断微血管疾病的潜力.
相关概念视频
Upsampling
265
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...
265
Fast Decoupled and DC Powerflow
241
The fast decoupled power flow method addresses contingencies in power system operations, such as generator outages or transmission line failures. This method provides quick power flow solutions, essential for real-time system adjustments. Fast decoupled power flow algorithms simplify the Jacobian matrix by neglecting certain elements, leading to two sets of decoupled equations:
241
Fast Fourier Transform
392
The Fast Fourier Transform (FFT) is a computational algorithm designed to compute the Discrete Fourier Transform (DFT) efficiently. By breaking down the calculations into smaller, manageable sections, the FFT significantly reduces the computational complexity involved. Direct computation of an N-point DFT requires N2 complex multiplications, whereas the FFT algorithm needs only (N/2)log2N multiplications, offering a much faster performance.
The computational efficiency of the FFT becomes...
The computational efficiency of the FFT becomes...
392
Reconstruction of Signal using Interpolation
249
Signal processing techniques are essential for accurately converting continuous signals to digital formats and vice versa. When a continuous signal is sampled with a period T, the resulting sampled signal exhibits replicas of the original spectrum in the frequency domain, spaced at intervals equal to the sampling frequency. To handle this sampled signal, a zero-order hold method can be applied, which creates a piecewise constant signal by retaining each sample's value until the next...
249
Doppler Effect - II
3.4K
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...
3.4K
Downsampling
192
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...
The Fourier transform of the decimated sequence reveals a combination of scaled and shifted versions of the original spectrum. This...
192

