题目：基于LabVIEW的PC通用胎心音采集系统

摘要：
本文详细阐述了基于PC机的胎心音采集系统的实现方案。
系统分为硬件和软件两部分。硬件由心音传感器、心音预处理电路、A/D卡、PC机组成。软件部分由胎心音信号采集部分，分析部分，波形显示部分和数据存储部分组成。
心音传感器采用NIHON KOHDEN TA-701T加速度型心音传感器。心音预处理电路为自行结合实验环境设计。A/D卡采用北京优采公司的UA301型USB接口12位A/D转换卡。实验所用PC为目前主流的中低端配置电脑。
系统软件构建在Windows 2000环境下，使用LabVIEW 7.0 Express编程平台进行编程开发。程序采集部分主要对A/D卡进行控制，控制采集硬件的设备开启与关闭、设备使用的采样率及采样通道的个数等一些相关设置。分析部分主要通过对数据的功率谱分析，进行一定的波形调理，以优化用于显示部分的数据。存储部分，使用高速磁盘流技术，占用很少的系统资源，将进行中高速采集的原始数据，无遗漏的保存起来，以便进行再分析。整个软件系统的运行控制以Queue技术作为保证，在充分使用系统时间碎片条件下，保护各个线程互不干扰，稳定不间断地数据采集，数据无缺失，且不会出现重复显示现象。
它开发的目的是改变传统的胎心音监护仪功能单一，数据处理手段原始的现状。充分利用PC的兼容性、可移植性、低成本及其强大的功能，现代编程技术的继承性和高度自动化的新一代虚拟仪器，构建具有无创性、方便快捷且费用低廉，与其它心血管检查方法有互补作用的，可作为临床、科研和教学的实用性系统。

关键字：胎心音，采集系统，LabVIEW

Title: PC Fetal Heart Sound Acquisition System Based on LabVIEW
Abstract :
This thesis intends to explore the means of the realization of a fetal heart sound acquisition system based on PC.
This system is based on two parts—the hardware and the software. The hardware part consists of a phonocardiographic sensor, a heart sound signal preprocessing circuit, an A/D card, and a personal computer, while the software one consists of a fetal heart sound acquisition program block, a signal analysis program block, a wave-form chart display program block and a data storage function block.
The phonocardiographic sensor used is the NIHON KOHDEN direct –contact acceleration-type heart-sound sensor Model TA-701T. The heart sound signal preprocessing circuit is designed and produced according to laboratorial need. The A/D card is the USB interfacing 12-bit one Model UA301 produced by Beijing Youcai Company, and the PC used is the extensively used moderate configuration one.
The software system is programmed with LabVIEW 7.0 Express under the Windows 2000 operation system. The acquisition program of it is used to switch on or off of the hardware equipments, initial the sampling rate, the number of acquisition channel and other relevant setups with the A/D card. The analysis program block works on the optimization of the data used for display through the analysis of the power spectrum of those data, and some signal conditioning. The storage part, with the use of the technique of high speed HDD data string, saves up the original data collected for further analysis while occupying little system resources. The programmatically controlling of the whole software system is under the technique of Queue, which enables full usage of time fragments of CPU, non-interdisturbance of individual threads, stabilization of the collecting of data, and non-missing and non-repetition of the data to be collected.
The purpose of this system is to change the present state of the simpleness of function and backwardness of data processing method of the present fetal heart sound warding equipments. It creates a non-invasive, convenient and low-priced system based on the compatibility, transplantability, low cost and powerful functions of personal computers，and the successivity feature of modern programming technology and the new highly automatic virtual equipments. It can be used as a supplement to other cardiovascular examination methods and at the same time be applied to clinical, research and teaching uses.

Key words: fetal heart sound, acquisition system, LabVIEW