An implantable
neural stimulation system, such as an auditory Fully Implantable
System (FIS), includes: (1) an
implanted device capable of providing desired tissue or
nerve stimulation; and (2) a
remote control unit that provides a mechanism for readily controlling the
implant device, i.e., for selectively adjusting certain stimulation parameters associated with the tissue stimulation of the
implanted device. The
remote control unit uses a first
signal path to send signals to the
implant device, and a second
signal path to receive signals from the
implant device. The combination of these two
signal paths provides a full-duplex channel between the
remote control unit and the implant device through which air appropriate control and status signals may be sent and received. In one embodiment, the first signal path comprises an
audio signal path through which audio control signals, e.g., a tone sequence or a 32-bit word FSK modulated between 300 and 1200 Hz, are sent; and the second signal path comprises a RF signal path through which a BPSK, QPSK or FM modulated RF signal is received. The full-duplex channel allows operation of the remote
control unit, i.e., allows signals to be successfully sent to and received from the implant device, from as far away as 45-60 cm from the implant device.