System and method for using impedance to determine proximity and orientation of segmented electrodes

摘要

A method for implanting a neurostimulation lead within a patient includes measuring impedances of electrodes on the lead in order to correctly position the lead relative to a target tissue region. The electrodes are circumferentially segmented electrodes that are spaced from each other about the longitudinal axis of the lead. When the difference between the impedances of the electrodes exceeds a threshold value, the lead is in the correct position. In accordance with another embodiment, impedance measurements are used to select which one of the electrodes is closest to the target tissue region. By determining which electrode has the highest impedance and which electrode has the lowest impedance, the type of tissue adjacent to each electrode can be determined based on the conductivity properties of the tissue. The target tissue region may be a spinal cord, a posterior longitudinal ligament, white matter, or gray matter.

主权项

1. A system for providing therapy to a patient, the system for use with a neurostimulation lead positioned relative to a target tissue region having different conductive properties than other tissue proximate the neurostimulation lead, the neurostimulation lead having a longitudinal axis and an electrode ring segmented into two segmented electrodes circumferentially spaced from each other about the longitudinal axis, the system comprising:
an impedance monitor configured for being coupled to the segmented electrodes and for measuring an impedance for each of the segmented electrodes to provide impedance data for each of the segmented electrodes, the impedance data for each of the segmented electrodes being dependent on conductive properties of tissue proximate to the segmented electrode; a processor configured for analyzing the impedance data for each of the segmented electrodes to select the segmented electrode from the two segmented electrodes of the electrode ring that is closest to the target tissue region; and a controller configured for instructing a neurostimulator to convey electrical stimulation energy from the selected segmented electrode.