"Electrical field ("E-field") sensor systems that sense displacement or
change in displacement of one body relative to another." In general, the
bodies 110, 112 are within an electrical field and displacement of a body
causes a change in the E-field. A field sensor 290 detects this change
and a processor 275 translates it to a change in position of the
displaced body 110. The E-fields are generated by electrodes (or an
electrode and a ground member) that generate the E-field. The systems
include detectors 240 that detect changes in the E-field, such as
capacitance, and transmit these to the processor 275.