The aim is to design a Modified Limb Lead (MLL) system, for specifically studying the characteristics of the atrial depolarization (P wave) and atrial repolarization (Ta wave) morphology in sinus rhythm healthy subjects. The present work investigated the involvement of the Ta wave in the MLL ECG recording and to study the characteristics and alternant of the Ta wave during the P-Ta interval. The MLL system is also used to record the ECGs in different subjects in order to study the characteristics and to assess the full duration of the Ta wave. The main focus is on the involvement of body surface potentials during normal atrial electrical activity and to assess the involvement of atrial repolarization wave in ECG. A modified limb electrode placed on the right side of the human torso which produces a MLL system is used to record the ECGs of the healthy subjects in sinus rhythm using the bipolar limb electrodes.
