胎儿监护仪的电路研究

Research on the Electric Circuit of the Ultrasound Fetal Monitor

胎儿监护仪是一种已经广泛应用于临床的医疗器械,超声波对胎儿的损伤虽然尚未有医疗界定,但临床上仍需通过提高胎儿监护仪超声波信号的发射效率以及回波信号的接收灵敏度来降低超声波信号强度,以避免未知损伤的发生。本文基于分立元件设计了可用于胎儿监护仪的超声发射、接收和解调电路,能够降低集成电路形式的电源损耗,可通过阻抗匹配和多级谐振放大提高回波信号的接收灵敏度,且电路结构简单,解调效率高。测试验证结果表明整体电路的性能较好。

The ultrasound fetal monitor has been a kind of clinically widely-used medical devices. Although ultrasound’s damage to fetuses is still ill-deifned, the transmitting efifciency of the fetal monitor’s ultrasound signals and the receiving sensitivity of echo signals need to be increased to reduce the signal intensity of ultrasound and avoid the occurrence of un-known damages in its clinical application. In this paper, the simply-structured transmitter, receiver demodulation circuits are constructed based on the separate components to reduce the power loss and consumption of integrated circuits. With the characteristics of high efifciency of demodulation, the circuits can increase the receiving sensitivity of echo signals through impedance matching and multi-stage resonance ampliifcation. The whole circuit has demonstrated its outstanding performance in the veriifcation test.