Patient posture determination and stimulation program adjustment in an implantable stimulator device using impedance fingerprinting

摘要

Methods and circuitry for determining an implanted-neurostimulator patient's position, and adjusting a situation program delivered by the neurostimulator based on the determined position, is disclosed. Impedance measurements of the patient's tissue are taken at the neurostimulator's electrodes, which measurements can comprise complex impedance measurements (magnitude and phase) taken at different frequencies. Such impedance measurements, which can be taken interleaved with stimulation therapy, are used to determine an “impedance fingerprint.” This fingerprint can be compared to other known fingerprints stored in the IPG, which known fingerprints are associated with particular stimulation programs. When a measured fingerprint matches one stored in the IPG, the stimulation program associated with the stored fingerprint is automatically used for patient therapy. As different measured fingerprints are encountered, the IPG can learn and store a new stimulation program for such fingerprint by remembering stimulation parameters selected by the patient when such fingerprint is encountered.

主权项

1. An implantable stimulator device, comprising:
a plurality of electrodes configured to provide electrical stimulation to a patient; and circuitry comprising an impedance algorithm configured to determine an impedance between a plurality of combinations of the electrodes at a plurality of different frequencies during quiet periods when the electrical stimulation at a first frequency is not occurring, and to determine a measured impedance fingerprint from the determined impedances, wherein the impedance algorithm is further configured to select a stimulation program to be provided to the electrodes in accordance with the measured impedance fingerprint.