Techniques for Sensing and Adjusting a Compliance Voltage in an Implantable Stimulator Device

摘要

Disclosed herein are methods and circuitry for monitoring and adjusting a compliance voltage in an implantable stimulator devices to an optimal value that is sufficiently high to allow for proper circuit performance (i.e., sufficient current output), but low enough that power is not needlessly wasted via excessive voltage drops across the current output circuitry. The algorithm measures output voltages across the current source and sink circuitry during at least periods of actual stimulation when both the current sources and sinks are operable, and adjusts the compliance voltage so as to reduce these output voltages to within guard band values preferably indicative for operation in transistor saturation. The output voltages can additionally be monitored during periods between stimulation pulses to improve the accuracy of the measurement, and is further beneficial in that such additional measurements are not perceptible to the patient.

主权项

1. An implantable medical device, comprising:
a source circuit coupled to a compliance voltage, wherein the source circuit is configured to source a sequence of current pulses to at least a first electrode; a sink circuit coupled to a reference voltage, wherein the sink circuit is configured to sink the sequence of current pulses from at least a second electrode; voltage sensor circuitry configured to measure a first voltage across at least the source circuit and a second voltage across at least the sink circuit, wherein the first and second voltages are measured between the current pulses when neither of the source or sink circuits is activated to issue one of the current pulses; and regulator circuitry configured to adjust the compliance voltage in accordance with at least the first and second voltages.