Multichannel implantable cochlear stimulator having programmable bipolar, monopolar or multipolar electrode configurations

A multichannel implantable cochlear stimulator (ICS) for use with an external wearable processor (WP) system, said ICS comprising:

• receiver means for receiving a data signal from the WP, the data signal comprising a series of data frames containing an end of frame signal, each data frame comprising a plurality of data words, each data word defining an amplitude for an output stimulation current for a different output channel of the ICS, and a command word for controlling a processor means in the ICS;
• power supply means coupled to said receiver means for extracting a raw power signal from the data signal and generating a plurality of power signals therefrom that provide operating power to the ICS;
• a multiplicity of output stages within said ICS, one for each of a multiplicity of output channels provided by said ICS, with each output stage having an "A" and a "B" stimulating electrode connected thereto;
• indifferent electrode switch means within said ICS for connecting an indifferent electrode to each output stage;
• processor means coupled to said receiver means, multiplicity of output stages, and power supply means for serially processing the plurality of data words and command word in each data frame received by the receiver means, said processor means comprising:
• command detector means responsive to the command words for controlling the functions of the processor means, including setting an electrode configuration in each output stage of the ICS,
• data word latching means for successively storing the data words,
• switch means for successively generating and coupling a signal voltage representative of the output stimulation signal defined by the data word stored by the data word latching means to successive ones of the multiplicity of output stages;
• and wherein
• each of the multiplicity of output stages is contained within the ICS, is powered by the power signals generated by the power supply means, and includes:
• refresh voltage controller means for generating an isolated refresh voltage for the output channel,
• a voltage controlled current source powered by the isolated refresh voltage controller means for amplitude controlling, in accordance with the signal voltages coupled from the switch means, an output stimulation current,
• electronic switching matrix means responsive to the command detector means for configuring the "A" and "B" electrodes of each output stage, and the indifferent electrode, in a selected one of at least the following four electrode configurations:
• (1) bipolar stimulation, wherein the output stimulation current flows between the "A" and "B" electrodes of the output stage, (2) monopolar A stimulation, wherein the output stimulation current flows between the "A" electrode of the output stage and the indifferent electrode, (3) monopolar B stimulation, wherein the output stimulation current flows between the "B" electrode of the output stage and the indifferent electrode, and (4) multipolar stimulation, wherein the output stimulation current flows between the "A" or "B" electrode of one output stage and the "A" or "B" electrode of another output stage.