一种胎儿心电信号采集系统的设计与实现

Design and implementation of FECG signal acquisition system

目的:针对传统的胎儿心电采集系统难以满足实时性和低幅度高噪声的问题,设计并实现一种基于片上系统(system on chip,SoC)的胎儿心电信号实时采集和显示系统。方法:PC机通过USB转串口线向ARM处理器(advanced RISC machines,ARM)发送命令,ARM对命令进行识别后控制ADS1294芯片工作。母亲腹壁上的生理信号通过标准的导联线传入ADS1294芯片,ADS1294将模拟信号转换成数字信号,并通过外围串行接口(serial peripheral interface,SPI)将转换后的信号送入ARM。ARM把数据封装成固定的格式,数据通过串口传输到PC机中,PC机再将滤波后的信号显示出来。结果:该系统能够从母亲腹壁上采集到胎儿心电信号,同时将胎儿心电信号转换成24位数字信号并将数据存储在PC机中。结论:该胎儿心电采集系统结构简单、性能优异,并且可应用于胎儿心电监护设备上,具有一定的实用价值。

Objective To design and implement a real-time FECG signal acquisition and displaying system based on system on chip （SoC） to eliminate the shortcomings of the traditional one in timeliness, low amplitude and high noise. Methods The command was sent to advanced RISC machine （ARM） processor from PC through USB serial port, and then recognized by ARM for the control of ADS1294 chip. The physiological signals at the maternal abdominal wall were introduced into ADS1294 chip by the standard cable. The chip transformed the analog signals into digital ones, and then the digital signals were sent to ARM by the serial peripheral interface （SPI）. The data were encapsulated by ARM with fixed formation and transmitted to PC, and then the filtered signals could be displayed on PC. Results The system could acquire FECG signals from the maternal abdominal wall, and transform them into 24-bit digital signals and then stored them in PC. Conclusion The FECG monitoring system has a simple structure and high performances, and can be used in FECG monitoring devices practically.