Patent ID: 7935051

Claim:
A system for accessing a surgical target site, comprising: a distraction assembly to create a tissue distraction corridor in a lateral, trans-psoas path to a targeted spinal site, wherein said distraction assembly includes an elongate inner element and first and second dilators, the elongate inner element being positionable in a lumen of the first dilator and at least one of the elongate inner element and the first dilator includes at least one stimulation electrode, and the second dilator being advanceable over the first dilator to the targeted spinal site; a retraction assembly to retract tissue from said tissue distraction corridor to thereby form an operative corridor in the lateral, trans-psoas path to a targeted spinal site, the retraction assembly being guidable along at least one dilator of the distraction assembly to said targeted spinal site, wherein the retraction assembly includes a plurality of retractor blades for engaging the tissue to maintain the operative corridor in the lateral, trans-psoas path to a targeted spinal site; and a control unit to transmit an electrical stimulation signal to said at least one stimulation electrode and to receive an electromyographic (EMG) sensor signal of a neuromuscular response of a nerve depolarized by said stimulation signal, the control unit including a display device with a graphical user interface that displays information indicative of at least one of nerve proximity and nerve direction in response to the EMG sensor signal.