Burst-pulse control of microstimulator for bladder controller

This paper presents a method for the control of the variable burst biphasic pulse of a bladder stimulator. The stimulator is used to pass current through the tissue and to generate useful action potentials. The binary-weighted digital-to-analog converter combined with a current mirror has been employed as a microstimulator because of its higher linearity without requiring the decoding of digital inputs. Given that the use of a biphasic pulse could prevent ion-charge accumulation in tissues, two pairs of switches controlled by different clock phases are implemented to provide the biphasic electrical stimulation pulses. According to measurement results, the pulse frequency can be programmed between 1.49 Hz and 47.66 Hz, the burst frequency can be controlled from 190.8 Hz to 763 Hz, and the pulse width can be adjusted between 21 μs and 325 μs. These stimulation parameters are adapted by the clock divider and by the number of controlled bits in the digital circuits.