According to the invention, a finger-operated switch for activating and operating an ultrasonic surgical handpiece is provided. The
power output of the surgical handpiece is responsive and proportional to the pressure applied to the finger-operated switch. The finger-operated switch includes, but not limited to, force sensitive resistors whose resistance is proportional to the force applied by the finger of the
human operator of the surgical handpiece, force sensitive capacitors whose
capacitance is proportional to the pressure, deflection or compression of the
insulation layer between two electrodes or is proportional to the spacing between the two conductive
layers, strain gauges mounted underneath or integral to the housing of the surgical handpiece such that the pressure applied thereto results in an output change in the strain gauges, magnets or ferromagnets encased or embedded in an
elastomer with a sensor inside the surgical handpiece that detects the
field strength of the
magnet and monitors changes relative to the force applied to the handpiece housing, and piezo film or piezo
ceramic whose charge or
voltage is proportional to the force applied.