Electromagnetic apparatus and method for nerve localization during spinal surgery

摘要

An electromagnetic pedicle awl utilizes a tightly focused time-varying magnetic flux to create a localized electromotive force (EMF) near the tip. The localized EMF creates localized eddy currents in nearby nerves which excite ionic nerve channels, the excitation being detected by an electromyographic recording device. The awl only excites nerves directly in front of and directly to the side of the tip. The awl is comprised of a tapered awl or drill tip in combination with a solid core surrounded by a solenoid. A pulsed electric current source drives the solenoid to create a time-varying magnetic field in the vicinity of the tapered tip. The awl or drill tip may be stationary with respect to the solenoid or it may rotate. The awl in combination with an EMG detector connected to a patient is sensitive to the pedicle hole position with respect to adjacent nerves and reduces false placement failure.