Patent ID: 6996435
Filing Date: 2006-02-07
Classification: A61B

Abstract:
1. An implantable amplifying circuit for recording electrical signals generated by a nerve and detected by a pair of electrode wires in contact with the nerve, the amplifying circuit comprising: a preamplifier having a pair of inputs for receiving signals from the pair of electrode wires, the preamplifier including a differential pair of input MOSFET transistors having a low input current that serves as a first protection circuit to limit current flow through the nerve and the electrode wires, a pair of bipolar transistors and a current mirror that are driven with differential outputs of the MOSFET input transistors and producing a single-ended nerve output signal; a common signal line adapted to connect a body ground of a patient to a common voltage of the amplifying circuit; a second protection circuit disposed in series with the common signal line including a parallel resistor/capacitor combination to limit current flow through the nerve and the common signal line.