医用超声系统增益补偿电路的设计

Design of a gain compensating circuit for medical ultrasonic system

背景:为使深度不同但性质相同的界面反射的回波信号能显示出相同的幅值,必须根据深度(即时间)逐步增大放大器的增益,而使超声波在传播衰减过程中所引起远距离反射波弱的情况得到相应补偿。目的:为了补偿医学超声系统中回波信号的传输衰减问题,提出了一种时间增益补偿电路设计方案,阐述电路设计依据和原理。方法:针对医用超声系统的特点选择高信噪比、高带宽的可变增益放大器件VCA610,实现超声的增益补偿电路。结果与结论:该设计方案有效地解决了医用超声软组织测量过程中由声程导致的回波信号的非线性补偿问题。与传统的分立元件电路相比,该方案具有电路简单,TGC控制信号稳定可靠以及调节灵活等优点,能准确地补偿超声波在人体内的衰减,从而为医学测量系统的设计提供了一个新的可靠方法。

BACKGROUND：To make the echo signals reflected by interface with different depth and same property display the same amplitude,amplifier gain much be gradually increased based on depth（time）,and the situation that weak long-distance reflected wave caused by ultrasonic wave in the ultrasonic transmission attenuation process must be compensated.OBJECTIVE：To compensate the propagation attenuation of the echo signal in the medical ultrasonic system,a time gain compensating （TGC） circuit design scheme is presented,and the design basis and principles of the circuit are briefly introduced.METHODS：Aiming to the medical ultrasound system features,the variable gain amplifier parts VCA610 with high SNR,high-bandwidth were chosen to realize the ultrasonic gain compensation circuit.RESULTS and CONCLUSION：The design effectively solved the non-linear compensation of echo signals caused by echo distance in the medical ultrasound soft tissue measurement.Compared with traditional discrete components circuit,the scheme had the characteristics of simple circuit,stable and reliable TGC control signal,and flexible adjustment,etc.It can accurately compensate the attenuation of ultrasound in the human body,thus,provides a new and reliable method for the medical measurement system design.