A mechanical force switch configured to be disposed along a longitudinal device axis of a medical device, the switch comprising: an electrically conductive switching piston forming a first of two electrical contacts, said piston having: a longitudinal piston axis to be disposed parallel to the longitudinal device axis; and a bias-device contact; a hollow body defining a body interior cavity in which said piston is movably disposed along said piston axis to define: a switch-making piston position at a first longitudinal position with respect to said body; and a switch-breaking piston position at a second longitudinal position with respect to said body different from said first longitudinal position; an end stop defining a second interior cavity in which said piston is movably disposed, said end stop being at least partly disposed in said body interior cavity; a bias device being disposed about at least a portion of said piston between said end stop and said bias-device contact and configured to impart a variable longitudinal bias thereagainst to retain said piston in one of two positions selected from said switch-making position and said switch-breaking position until an external force imparted to said piston along said longitudinal piston axis exceeds said longitudinal bias and, when the external force exceeds said longitudinal bias, said piston moves to the other of said two positions, a magnitude of said longitudinal bias being dependent upon a longitudinal position of said end stop within said body interior cavity; and an electrically conductive second contact electrically insulated from said piston and forming a second of said two electrical contacts, said first and second electrical contacts being in said switch-making state when said piston is in said switch-making position and in said switch-breaking state when said piston is in said switch-breaking position. a longitudinal piston axis to be disposed parallel to the longitudinal device axis; and a bias-device contact; a hollow body defining a body interior cavity in which said piston is movably disposed along said piston axis to define: a switch-making piston position at a first longitudinal position with respect to said body; and a switch-breaking piston position at a second longitudinal position with respect to said body different from said first longitudinal position; an end stop defining a second interior cavity in which said piston is movably disposed, said end stop being at least partly disposed in said body interior cavity; a bias device being disposed about at least a portion of said piston between said end stop and said bias-device contact and configured to impart a variable longitudinal bias thereagainst to retain said piston in one of two positions selected from said switch-making position and said switch-breaking position until an external force imparted to said piston along said longitudinal piston axis exceeds said longitudinal bias and, when the external force exceeds said longitudinal bias, said piston moves to the other of said two positions, a magnitude of said longitudinal bias being dependent upon a longitudinal position of said end stop within said body interior cavity; and an electrically conductive second contact electrically insulated from said piston and forming a second of said two electrical contacts, said first and second electrical contacts being in said switch-making state when said piston is in said switch-making position and in said switch-breaking state when said piston is in said switch-breaking position. a switch-making piston position at a first longitudinal position with respect to said body; and a switch-breaking piston position at a second longitudinal position with respect to said body different from said first longitudinal position; an end stop defining a second interior cavity in which said piston is movably disposed, said end stop being at least partly disposed in said body interior cavity; a bias device being disposed about at least a portion of said piston between said end stop and said bias-device contact and configured to impart a variable longitudinal bias thereagainst to retain said piston in one of two positions selected from said switch-making position and said switch-breaking position until an external force imparted to said piston along said longitudinal piston axis exceeds said longitudinal bias and, when the external force exceeds said longitudinal bias, said piston moves to the other of said two positions, a magnitude of said longitudinal bias being dependent upon a longitudinal position of said end stop within said body interior cavity; and an electrically conductive second contact electrically insulated from said piston and forming a second of said two electrical contacts, said first and second electrical contacts being in said switch-making state when said piston is in said switch-making position and in said switch-breaking state when said piston is in said switch-breaking position.