Design Of Data Acquisition System For PCG And ECG Signal

In heart disease,congenital heart disease is a typical type of cardiovascular disease that we are very familiar with.From the medical analysis,changes in the signal of heart sounds and ECGs are early physiological responses to congenital heart disease,so analyzing the features of heart sounds and ECG signals provides an important basis for early screening and diagnosis and treatment of congenital heart disease.This paper studies the data acquisition system of heart sound ECG signal to help medical staff to play an auxiliary role in the diagnosis and treatment of congenital heart disease.It is of great practical significance to try to develop a collection and analysis device for heart sound ECG signals.In this paper,the sensor,signal conditioning circuit,NI(National Instruments)data acquisition card(USB-6002)as the lower computer and the programming software LabVIEW(Laboratory Virtual Instrument Engineering Workbench)and MATLAB to construct heart sound ECG data acquisition system.The system is divided into two ways to simultaneously collect heart sound signals and ECG signals.The hardware circuit uses a 5V regulated power supply to supply power.One heart sound signal passes through a conditioning circuit composed of a filter,an audio power amplifier,and a signal single-end-to-two-end output,etc.,to achieve simultaneous analysis of waveforms after auscultation and denoising.The other way is to use the conditioning circuit formed by the preamplifier,main amplifier,filter,and right leg drive circuit to achieve the function of amplification and filtering.Then,the conditioned heart sound(PCG)signal and electrocardiogram(ECG)signal are sent to the USB-6002 analog input for analog-to-digital conversion(A/D).After that,the data acquisition card is connected to the PC with a USB cable,and a feature-rich human-computer interaction interface is programmed and designed using LabVIEW.It is mainly divided into five functional modules: the system startup interface module,data acquisition module,data storage module,and database.Management module,data processing module.The database management module can be divided into two types: user login database and heart sound ECG database.The data processing module uses MATLAB software to complete wavelet denoising of heart sound ECG signals.The circuit used for signal conditioning in this paper is not only simple and low power consumption,but also easy to implement low cost.Using LabVIEW programming to achieve the signal acquisition and display storage;use the database connection tool and LabSQL to achieve standardized and efficient data storage;and use the form of wavelet denoising in the form of the wavelet,so that the waveform profile of the heart sound ECG signal after denoising becomes Smooth and clear,the overall denoising effect is significant.Really implements a simple programming technique that controls the connection between the instrument and the software.