Development of an embedded system for real time Heart Rate Variability analysis

Electrocardiogram (ECG) is the most preferably used noninvasive test for diagnosis of cardiac rhythm. Irregular rhythm of heart beats is measured in terms of Heart Rate Variability (HRV). Analysis of HRV plays an important role in automated diagnosis of cardiac status. This paper deals with development of an embedded system suitable for real time HRV analysis. A low cost embedded system for monitoring an ECG has been developed using operational amplifiers and a Microchip´s microcontroller. Digitized ECG has been transmitted serially to computer for real time analysis of HRV. Nonlinear energy associated with QRS complex is highest amongst the ECG beat. This feature has been utilized for QRS detection. Rest all the statistical markers for HRV are then computed with reference to the detected QRS. HRV analysis of 10 real subjects has been carried out using the embedded system. Results show that the proposed low cost embedded system is suitable for real time HRV analysis.