Measurements of ultrasonic pulse distortion produced by human chest wall
Measurements of ultrasonic pulse distortion produced by human chest wall
复制标题
人体胸壁产生的超声脉冲畸变测量
DOI：
10.1121/1.414170
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发表时间：
1995
影响因子：
2.4
通讯作者：
R. Waag
中科院分区：
文献类型：
--
作者：
L. M. Hinkelman;Thomas L. Szabo;R. Waag
通过二维孔径测量了通过人体胸壁标本传输产生的超声波波前畸变。测量的脉冲波阵面有时会被传输脉冲与肋骨骨和软骨结构相互作用产生的二次波阵面破坏。二次波前在接收到的波形中产生了较大的畸变，干扰了软组织不均匀性引起的波前畸变的测定。通过减小分析区域，将二次波前的影响降到最低。计算了这些受限区域与参考区域之间的到达时间和能级差异，从而解释了几何延迟和扩散。通过计算波形相似系数来评估频谱变化，该系数因波形形状的变化而从1.0下降。16种不同肋间隙测量波形到达时间波动的平均（±s.d） rms值为21.3（±8.4）ns，平均相关长度为2.50（±0.62）mm，能量水平波动的平均rms值为1.57（±0.45）dB，平均相关长度为1.98（±0.33）mm，平均波形相似系数为0.964（±0.012）。对于胸壁标本的软组织不均匀性，平均均数到达时间和能量水平波动小于腹壁测量值的一半。然而，虽然到达时间波动的平均相关长度不到腹壁的一半，但能级波动的平均相关长度与腹壁相似。
Ultrasonic wavefront distortion produced by transmission through human chest wall specimens was measured over a two-dimensional aperture. Measured pulse wavefronts were sometimes disrupted by secondary wavefronts produced by interaction between the transmitted pulses and the bone and cartilage structures of the rib cage. The secondary wavefronts produced large distortions in the received waveforms and interfered with the determination of the wavefront distortion caused by soft-tissue inhomogeneities. The effects of secondary wavefronts were minimized by reducing the region of analysis. Differences in arrival time and energy level between these restricted regions and references that account for geometric delay and spreading were computed. Spectral changes were assessed by calculating a waveform similarity factor that is decreased from 1.0 by changes in waveform shape. For 16 different intercostal spaces, the arrival time fluctuations of the measured waveforms had an average (±s.d.) rms value of 21.3 (±8.4) ns and an average correlation length of 2.50 (±0.62) mm. The energy level fluctuations had an average rms value of 1.57 (±0.45) dB and an average correlation length of 1.98 (±0.33) mm, and the average waveform similarity factor was 0.964 (±0.012). For soft-tissue inhomogeneities in chest wall specimens, the average rms arrival time and energy level fluctuations were less than half those measured for the abdominal wall. However, although the average correlation length of the arrival time fluctuations was less than half that found for the abdominal wall, the average correlation length of the energy level fluctuations was similar to that of the abdominal wall.
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影响因子：
2.4
作者：
HINKELMAN, LM;LIU, DL;WAAG, RC
通讯作者：
WAAG, RC
影响因子：
2.4
作者：
LIU, DL;WAAG, RC
通讯作者：
WAAG, RC
使用到达时间的最小均方误差估计对超声脉冲焦点退化进行时移补偿。
DOI：
10.1121/1.408348
发表时间：
1994
期刊：
The Journal of the Acoustical Society of America
影响因子：
--
作者：
Liu,DL;Waag,RC
通讯作者：
Waag,RC
影响因子：
2.4
作者：
HINKELMAN, LM;LIU, DL;STEINBERG, BD
通讯作者：
STEINBERG, BD