一种基于数字解调模式的无线超声多普勒胎儿监护仪系统的设计及实现

Design and implementation of a wireless ultrasound fetal heart monitoring system based on digital demodulation mode

传统超声多普勒胎儿监护仪均采用模拟解调进行胎儿心率的分析,由于该模式下的解调信号为单路信号,无法进行矢量分析,因此在实际应用过程中,存在着对二尖瓣的正负向运动的重复识别,造成心率翻倍现象。设计并实现了一种基于数字解调模式的无线超声多普勒胎儿监护系统,其采用时域加窗方式对超声回波信号进行数字解调处理,并根据计算所得到的矢量速度曲线进行心率分析,该系统能够有效避免心率翻倍现象。同时,该系统采用主机与探头之间的数据无线传输方案,极大地方便了操作人员使用。根据标准胎心仿体测试结果,所提系统能够有效抑制传统设备所存在的心率翻倍缺陷,实现稳定、可靠和便捷的胎儿监护。

Traditional ultrasound Doppler fetal monitor uses analog demodulation to analyze fetal heart rate. Because the demodulated signal in this mode is a single channel signal, vector analysis can not be carried out. Therefore, in the practical application process, there is repeated recognition of positive and negative movement of mitral valve, resulting in the phenomenon of heart rate doubling. In this research, designed and implemented a wireless ultrasound Doppler fetal monitoring system based on digital demodulation mode. The system uses the time domain windowing method to demodulate the ultrasonic echo signal, and analyzes the heart rate according to the vector velocity curve. The system can effectively avoid the phenomenon of heart rate doubling. At the same time, the system uses the data wireless transmission scheme between the host and probes, which greatly facilitates the use of operators. According to the results of standard fetal heart phantom test, the system can effectively solve the defect of heart rate doubling existing in traditional equipment, and realize stable, reliable and convenient fetal monitoring.