A sensor array apparatus for monitoring medical signals includes a flexible substrate adapted for positioning relative to the torso of a patient. The flexible substrate includes a central segment defining a central axis and is adapted to generally conform to an area extending along the sternum of a patient. The flexible substrate further includes an upper segment extending traversal across the central segment and adapted to generally conform to the chest area of a patient and a lower segment extending traversal across the central segment and adapted to generally conform to the abdominal area of the patient. The apparatus further includes a medical electrode disposed on at least one of the segments and a connector in electrical communication with the medical electrode and adapted to connect to an electronic monitoring system.