A mechanical force switch for a medical device, wherein the switch comprises a switching piston (10), a hollow body (30) defining a body interior cavity (32, 34) in which the switching piston is moveably disposed along a piston axis to define a switch-making piston position and a switch-breaking piston position, and a bias device (50) imparting a variable longitudinal bias to the switching piston to retain the switching piston in the switch-making piston position or the switch-breaking piston position until an external force imparted to the switching system exceeds the longitudinal bias. An electrically-conductive contact (80, 160) is physically coupled to the switching piston and moveable between the two positions to define a switch-making state and a switch-breaking state, respectively.
