Sample and hold circuitry for monitoring voltages in an implantable neurostimulator

摘要

Sample and hold circuitry for monitoring electrodes and other voltages in an implantable neurostimulator is disclosed. The sample and hold circuitry in one embodiment contains multiplexers to selected appropriate voltages and to pass them to two storage capacitors during two different measurement phases. The capacitors are in a later stage serially connected to add the two voltages stored on the capacitors, and voltages present at the top and bottom of the serial connection are then input to a differential amplifier to compute their difference. The sample and hold circuitry is particularly useful in calculating the resistance between two electrodes, and is further particularly useful when resistance is measured using a biphasic pulse. The sample and hold circuitry is flexible, and can be used to measure other voltages of interest during biphasic or monophasic pulsing.

主权项

1. Circuitry for an implantable stimulator device configured to provide a stimulation pulse having at least first and second phases between first and second electrodes, the circuitry comprising:
a first capacitor; a second capacitor; and switching circuitry, wherein the switching circuitry is configured to:
store a first voltage between the first and second electrodes across the first capacitor during the first pulse phase,store a second voltage between the first and second electrodes across the second capacitor during the second pulse phase, andserially connect the first and second capacitors to produce a sum of the first and second voltage after the second pulse phase.