USB Based ECG Acquisition System

Abstract

Acquisition of ECG data from patients in Intensive Care Unit (ICU) following surgery is a vital part of cardiac disease detection and rehabilitation monitoring and therefore it is a standard function of ICU physiological monitors and monitoring systems. Recently, some authors have introduced continuous ECG monitoring and processing into cardiac disease prediction research. Such studies have to be performed on as many subjects as possible in order to acquire large enough amount of data, which imposes a necessity for simultaneous data acquisition from multiple patients. Current equipment found in a typical ICU is not designed to fulfill such demands and usually cannot be easily interfaced to a standard computer intended for signal data recording. The aim of this project was to design and develop a simple ECG acquisition system composed of a single recording and storage device (personal computer) and a sufficient number of pickup ECG amplifiers simultaneously connected to the recording device on a single bus. We chose USB for interconnecting the system because of its speed, reliability and power-supply and plug and play capabilities. USB is widely spread and every modern computer has multiple USB ports used for connecting peripheral devices and as such it fulfilled the demands of our project. In order to allow complete control of the recording device to amplifier interface we developed custom USB drivers designed for Microsoft Windows XP operating system. The system was evaluated with eight amplifiers working simultaneously and no data loss was detected.