Patent ID: 7578819

Claim:
A method for locating neural tissue in a patient's intervertebral foramen, so that the neural tissue can be avoided when decompressing the intervertebral foramen, the method comprising: advancing a probe along a path within an intervertebral foramen, the probe having a first surface oriented anteriorly and towards neural tissue within the intervertebral foramen and a second surface oriented posteriorly and away from the neural tissue; delivering a first electrical current to a first electrode along the first surface of the probe; delivering a second electrical current to a second electrode along the second surface of the probe; verifying that the neural tissue is anterior to the probe in the intervertebral foramen by monitoring neural response to the first and second electrical currents; determining a first threshold amount of electrical current required to stimulate measurable action potentials in the neural tissue via the first electrode; determining a second threshold amount of electrical current required to stimulate measurable action potentials in the neural tissue via the second electrode; comparing the first and second threshold amounts of current to determine which of the first and second surfaces is closest to the neural tissue; calculating a ratio of the threshold amount of current applied to the electrode farthest from the neural tissue compared to the threshold amount of current applied to the electrode closest to the neural tissue; and removing tissue from the intervertebral foramen posterior to the path of the probe with a tissue modification device, to reduce impingement of the neural tissue when the ratio is greater than or equal to 2.