3-Lead Wireless ECG

This document presents an overview of the design process undertaken, as well as the project specifications in the design and implementation of a low cost wearable ECG system. A detailed explanation of the various modules of the design and their implementations is provided. Each module was successfully simulated and then implemented. There exists a demand for such systems as current implementations are complex to use, high in cost and inaccessible to the vast majority of South Africans. The system design aims to provide solutions to the problems encountered in acquiring from the body, as well as providing remote transmission, of ECG data. Two separate devices have been constructed to achieve the overall goal. A remote device is attached to the person being monitored. The remote device acquires the raw ECG data from the Leads which are placed in predefined areas of the body. The necessary filter requirements (for ECG frequency band selection) and formatting of filtered ECG data (for transmission) both occur in the DSPic microcontroller which is present in the mobile unit. The data is transmitted wirelessly using a low-cost RF Transceiver. A second Data acquisition unit is connected to USB port of a P.C. The unit has a second transceiver to receive and decode the data received from the remote unit. The data is then transmitted via the USB to the P.C for display. A user friendly graphical interface (GUI) was constructed using Visual Basic 6.0 enterprise edition. The GUI allows for the monitoring of real time ECG data. A database was implemented using MS Access 2000. This allowed for storage of the ECG data. The report provides a theoretical section on the 3-Lead ECG as well as how the heart generates the ECG signal. The design is then dissected into various models which are discussed individually. A separate section is provided on the integration of these modules.