1. A non-transitory computer-readable storage medium for storing instructions for invoking a function of a diagnostic instrument, the code, once executed, causing the instrument to display: a first navigational menu including at least one display element, the at least one display element having a touch sensitive active region therein and a graphical representation of functionality invoked via user selection of the display element by user contact with the touch sensitive active region, the display element and the touch sensitive active region being located on the same surface of a display screen of the diagnostic instrument; and a second navigational menu configured to be displayed responsive to contact on the touch sensitive active region of the at least one display element, the second navigational menu including a selection group related to a test suite of the diagnostic instrument; wherein the first and second navigational menus are displayed sized and positioned to be responsive to a gloved finger; and wherein the display screen is pressure sensitive and provides coordinate information regarding contact on the display screen including depth information, the depth information is used to determine a pressure applied to the display screen, and the pressure is used to define a user contact area.
7. The medium of claim 1 , wherein the touch sensitive active region comprises an area having a polygonal shape of at least ¼ square inch.