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首页> 外文期刊>IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control >Attenuation coefficient and propagation speed estimates of intercostal tissue as a function of pig age
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Attenuation coefficient and propagation speed estimates of intercostal tissue as a function of pig age

机译：猪肋间组织的衰减系数和传播速度估计

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摘要

Attention coefficient and propagation speed of intercostal tissues were estimated from chest walls removed postmortem (pm) from 15 5.3 /spl plusmn/ 2.3-day-old, 19 31 /spl plusmn/ 6-day-old, and 15 61 /spl plusmn/ 3-day-old crossbred pigs. These ultrasonic propagation properties were determined from measurements through the intercostal tissues, from the surface of the skin to the parietal pleura. The chest walls were placed in a 0.9% sodium chloride solution, sealed in freezer bags, and stored at -15/spl deg/C prior to measurements. When evaluated, chest-wall storage time ranged between 1 and 477 days pm. All chest walls were allowed to equilibrate to 22/spl deg/C in a water bath prior to evaluation. There was an age dependency of the intercostal tissue propagation speed, with the speed increasing with increasing age. The attenuation coefficient of intercostal tissue was shown to be independent of the age of the pig at the discrete frequencies of 3.1 and 6.2 MHz. For pig intercostal tissues, the estimated attenuation coefficient over the 3.1-9.2 MHz frequency range was A = 1.94f/sup 0.90/ where A is in decibels per centimeter (dB/cm) and f is the ultrasonic frequency in megahertz. In order to determine if there was an effect of storage time pm on estimates of attenuation coefficient, a second experiment was conducted. Five of the youngest pig chest walls measured on day 1 pm in the first experiment were stored at 4/spl deg/C prior to the first evaluation then stored at -15/spl deg/C before being measured again at 108 days pm. There was no difference in the estimated intercostal tissue attenuation coefficient as a function of storage time pm.
机译：死后（pm）从15 5.3 / spl plusmn / 2.3天龄，19 31 / spl plusmn / 6天龄和15 61 / spl plusmn /中去除的胸壁估计肋间组织的注意系数和繁殖速度3天大的杂种猪。这些超声传播特性是通过对肋间组织（从皮肤表面到顶胸膜）的测量确定的。将胸壁置于0.9％的氯化钠溶液中，密封在冷冻袋中，并在测量前以-15 / spl℃/℃的温度保存。评估时，胸壁存储时间为下午1到477天。在评估之前，在水浴中使所有胸壁平衡至22 / spl℃/℃。肋间组织的繁殖速度与年龄有关，并且随着年龄的增长而增加。结果表明，在3.1和6.2 MHz的离散频率下，肋间组织的衰减系数与猪的年龄无关。对于猪肋间组织，在3.1-9.2 MHz频率范围内的估计衰减系数为A = 1.94f / sup 0.90 /，其中A以分贝/厘米（dB / cm）为单位，f是以兆赫兹为单位的超声频率。为了确定存储时间pm对衰减系数的估计是否有影响，进行了第二个实验。在第一个实验的下午1点测量的最年轻猪胸壁中的五个，在第一次评估之前以4 / spl deg / C保存，然后在-15 / spl deg / C存储，然后在晚上108天再次测量。估计的肋间组织衰减系数与存储时间pm的函数没有差异。

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