#$%^&*AU2015200204A120150205.pdf#####Abstract A device for gathering data has first and second electrodes. The first electrode is coupled to a surface of interest, and the second electrode is coupled to "everything else" or "the air". The first electrode is shielded from the second, and from most sources of parasitic capacitance, by a shield that is driven by an active driver that drives the shield to track, and ideally to match, the instantaneous potential of the electrode. The second electrode is likewise shielded in a similar way from most sources of parasitic capacitance. These shields likewise help to limit the extent to which RFI from the device electronics couples with either of the electrodes. In this way the sensing device achieves a markedly better signal-to-noise ratio at frequency bands of interest.1/1 FIG. 1 106 107 10 1 108 103 102 FIG. 2 Prior Art /-204 208 N 201 209-.E 203 102 FIG. 3 104\ 301 303 106 307 3708 309 103-, 302 305 105- 36
