There is provided a metal structure that holds the display unit, as the main structure, and a casing structure that is integrally molded from resin onto the metal structure. The output signals contain errors due to component shortcomings and manufacturing imperfections. Parameters representative of cardiac rhythm are derived from the far-field cardiac electrical signals. In response to receiving the input, the ME may display a view of the second portion of the graphical model. Similar and related methods, apparatuses, systems, and computer program products are also provided.