Bhagat P, Hajjar W, Kadaba M
Ultrasonics. 1976 Nov;14(6):283-5. doi: 10.1016/0041-624x(76)90038-x.
Nerve-muscle preparations of Sprague Dawley rats were exposed to low dosage ultrasound. The objectives were to measure the velocity of propagation and attenuation of ultrasonic energy in both the relaxed and contracted states. A tension-measuring system and associated ultrasonic instrumentation were designed to measure the tension developed in stimulated muscle and its corresponding acoustic parameters, ie the attenuation coefficient, alpha (db cm-1) and the velocity of propagation, c (ms-1). Each test was performed at ultrasonic frequencies 3.1, 5.35, and 7.68 MHz and with the preparation maintained at 23 +/- 0.5 degrees C. Attenuation of ultrasonic energy was observed to increase by 10 +/- 0.5% in the active state from its value in the relaxed state. The relation between the attenuation and the acoustic frequency was found to be approximately linear over the frequency range tested. The velocity of propagation in the active state did not change appreciably from its value in the relaxed state and was observed to be independent of the acoustic frequency in the range used.
将斯普拉格·道利大鼠的神经肌肉标本暴露于低剂量超声下。目的是测量超声能量在松弛和收缩状态下的传播速度和衰减。设计了一个张力测量系统和相关的超声仪器，以测量受刺激肌肉中产生的张力及其相应的声学参数，即衰减系数α（分贝/厘米）和传播速度c（米/秒）。每次测试在3.1、5.35和7.68兆赫的超声频率下进行，标本保持在23±0.5摄氏度。观察到超声能量的衰减在活动状态下比在松弛状态下的值增加了10±0.5%。在所测试的频率范围内，发现衰减与声频之间的关系近似线性。活动状态下的传播速度与松弛状态下的值相比没有明显变化，并且在所使用的频率范围内观察到与声频无关。
