Rabe H, Grohs B, Schmidt R M, Schloo R, Bömelburg T, Jorch G
Department of Paediatrics, University Hospital of Münster, FRG.
Pediatr Radiol. 1990;20(4):277-81. doi: 10.1007/BF02019666.
Acoustic power output levels were measured in four different pulsed Doppler systems (transcranial, Duplex mode, colour mode, miniature for continuous monitoring) currently used for examination of fetal and infant blood flow velocities. The frequencies of the transducers ranged from 2 to 8 MHz. The devices were studied at three to five different intensity settings. The measurements were performed using the radiation force balance of the Fraunhofer-Institut, which was especially adapted for this study. Each of the four devices was tested while running in its commonly used mode, and comparison showed that their acoustic power values varied widely: 96.8 mW (2 MHz, EME TC2-64B), 8.7 mW (5 MHz, ATL Mk 500), 61.9 mW (3.5 MHz, Acuson 128) and 13.5 mW (5 MHz, HP 77020). All transducers had total power output levels below the limits recommended by the American Institute for Ultrasound in Medicine and Biology in the conclusions on a thermal bioeffects mechanism, which were approved in October 1987.
在目前用于检测胎儿和婴儿血流速度的四种不同脉冲多普勒系统（经颅、双工模式、彩色模式、用于连续监测的微型系统）中测量了声功率输出水平。换能器的频率范围为2至8兆赫。在三到五个不同的强度设置下对这些设备进行了研究。测量是使用弗劳恩霍夫研究所的辐射力平衡进行的，该平衡是专门为此研究而调整的。四个设备中的每一个都在其常用模式下运行时进行了测试，比较表明它们的声功率值差异很大：96.8毫瓦（2兆赫，EME TC2 - 64B）、8.7毫瓦（5兆赫，ATL Mk 500）、61.9毫瓦（3.5兆赫，Acuson 128）和13.5毫瓦（5兆赫，HP 77020）。所有换能器的总功率输出水平均低于美国医学和生物学超声学会在1987年10月批准的关于热生物效应机制的结论中推荐的限值。
