The overarching aim of this project is to modulate the pulse-width during stimulation of pedicle screws and record the response thresholds associated with each PWM setting. During this initial phase of the investigation, no further data will be collected.

In vivo electrical stimulation of pedicle screws is a well-documented modality for evaluating potential breach of the pedicle wall. However, previous research has focused primarily on the stimulation threshold intensity required to elicit a neurophysiological response. Other stimulation parameters, such as pulse-width, remain uninvestigated. The goal is to obtain data on the pulse-width vs. CMAP relationship.

Inclusion Criteria:

• A patient will be eligible for study participation once they have been booked for a surgery involving pedicle screw placement and intraoperative neuromonitoring.

Exclusion Criteria:

• The study excludes neonates, minors, pregnant women, prisoners and cognitively impaired patients.