A low-cost solution to follow the evolution of arrhythmic patients

The aim of this paper is to discuss the main features of a system designed to study the evolution of arrhythmic patients doing their daily activities. The proposed system is composed by three parts: a small battery-powered device designed to acquire and transmit, via Bluetooth, an ECG channel; a mobile application based on Android operating system to process the ECG and a web application. The ECG device is able to acquire and transmit the ECG continuously since it is turn on. The Android application receives the ECG data; QRS complexes are detected and classified and RR intervals are measured to compute heart rate. All these information is uploading to a web application using GSM/GPRS network and HTTP protocol. The web application stores each ECG file in a SQL database; cardiologists can check ECG strips and analyze trend charts associated to each patient. Also, cardiologist can call any patient in order to adjust his drug treatment. The ECG device is easy to use, patient only have to attach three electrodes to his skin and press the ON/OFF button. Two ECG device's prototypes have been tested according to the IEC 60601-2-47 standard and all the tests were passed successfully. The Android application has been tested with three hundred three-minute ECG strips; Bluetooth communication was without errors. QRS complex detection algorithm was tested with MIT-BIH database and the sensitivity was 99,03%. Web application provides graphical tools to analyse the ECG and its measurements. The SQL database has been tested without any problem to store or recover information.