Method for improving effective dynamic range of neural stimulation for artificial cochlear system, and reconfigurable current DAC-based neural stimulation IC chip therefor
The present disclosure discloses a method for improving an effective dynamic range including acquiring a hearing profile of a user, setting a section between a T level and a C level as a target range of a stimulation current for each of a plurality of electrodes included in an electrode array of a cochlear implant system based on the hearing profile, and mapping a plurality of current levels to an output current within the target range.
1 . A method for improving an effective dynamic range, the method comprising:
acquiring a hearing profile of a user;
setting a section between a T level and a C level as a target range of a stimulation current for each of a plurality of electrodes included in an electrode array of a cochlear implant system based on the hearing profile; and
mapping a plurality of current levels to an output current within the target range.
2 . The method of claim 1 , wherein in the mapping of the output current within the target range, a minimum current level among the plurality of current levels is mapped to the T level, a maximum current level among the plurality of current levels is mapped to the C level, and the other current levels are mapped to a current between the T level and the C level in a linear, exponential, or piecewise linear manner.
3 . A neural stimulation IC chip based on a current DAC, the neural stimulation IC chip comprising:
a clock & data recovery block configured to recover received data by using a clock;
a back telemetry block configured to transmit data;
a neural stimulator configured to transmit stimulation pulses to a plurality of electrodes included in an electrode array of a cochlear implant system;
a neural recorder configured to monitor electrode impedance and an electrically evoked compound action potential through the plurality of electrodes; and
a digital controller configured to control an input signal of the neural stimulator according to data decoded by the clock & data recovery block and configured to transmit a signal received from the neural recorder to an external device through the back telemetry block,
wherein the neural stimulator includes an offset DAC for setting a current offset and an incremental DAC for adding a predetermined current to the current offset, and generates and outputs a final output current by using output currents of the offset DAC and the incremental DAC.
4 . The neural stimulation IC chip of claim 3 ,
wherein the current offset is set to a T level based on a hearing profile of a user,
wherein the incremental DAC adds a predetermined amount of current such that a plurality of current levels are mapped to an output current between the T level and the C level.