The primary aim of this clinical investigation is to examine a prototype of a quantitative monitoring instrument that will meet most, if not all, of the clinical requirements.

This is a blinded, single-center, prospective study in patients during surgery, requiring use of neuromuscular blockade. Neurostimulation will be used to monitor objective responses, as per current clinical routine. Data collection of Tetragraph EMG responses will be unavailable to the clinician for clinical decision-making, as per current clinical routine, but will be stored on the interfaced SD card.

Inclusion Criteria

1. Age 18 years or older.
2. American Society of Anesthesiology (ASA) physical status I-III criteria (Table I).
3. Subject has provided verbal consent
4. BMI <39

Exclusion Criteria

1. Presence of an underlying neuromuscular disease.
2. Presence of renal or hepatic disease.
3. Subject has open skin sores in the locations needed for electrode application (forearms).
4. Patients on oral anticholinesterase, anti-seizure medications, and magnesium sulfate.

The study population for this study includes patients receiving neuromuscular blocking agents during a surgical procedure.