Biological processes voltage discharge and amplification appts. - has shielded discharge electrode insulated from body and connected via shielded wire to FET electrode

摘要

Appts. for discharging and amplifying voltages occuring in biological process comrpises a discharge electrode (10) to which is connected an amplifier. The electrode is separated by an insulating layer (16) from the bodily location selected for deriving the voltages, and shielded on its other sides, and connected via a shielded wire (18) connected to the electrode shield to the first gate electrode of a double-gate FET (24) in source circuit. In the supply wire leading to the first gate electrode is a first resistor (32) disposed within the wire shield (20) which is connected to the second gate electrode and source electrode. The appts. is used e.g for EEG's and ECG's and is free from electrical interference.