Withdrew study equipment issue.

The purpose of this study is to examine whether noninvasive, transcutaneous vagal nerve stimulation (tcVNS) (Gammacore Sapphire Device) can help restore consciousness in patients in the Operating Room and Post Anesthesia Care Unit (PACU). To examine whether tcVNS administered in the PACU can help reduce delirium and depression post-surgery, speeding up cognitive recovery from anesthesia, and finally determine if tcVNS can expedite discharge from the PACU.

Inclusion Criteria:

• Aged > 18 years of age
• Patients undergoing lumbar surgery for degenerative disc disease or spinal stenosis involving two or more levels
• Mini-Mental State Examination (MMSE) score ≥ 15-accept mild
• Ability to use a keyboard
• Able to understand and communicate in English
• Be able to consent independently
• Women of child-bearing age must be comfortable confirming a negative pregnancy prior to participating in the study.
• Must not be involved in any other research intervention study testing neurobehavioral functioning
• Good internet connectivity and ability to use computer, smart phone or good telephone connectivity (follow up)

Exclusion Criteria:

• Age < 18 years of age
• History of vagotomy (cutting the vagus nerve)
• History of bradycardia, heart block, prolonged QT syndrome, brugada syndrome, heart failure with ejection fraction less than 35% and/or New York Heart Association symptoms
• MMSE < 15
• History of seizure disorder or intracranial hemorrhage
• Patients with carotid stenosis
• Patients with aneurysms
• Other neurological diagnoses or a diagnosis of severe psychiatric disorder (e.g., psychosis) or a reported childhood learning disability
• Pregnancy, breastfeeding
• Active addiction history
• ECG adhesive allergy
• Severe aphasia, preventing subject from understanding the protocol and giving written consent
• Patients with an active implantable medical device, such as a pacemaker, hearing aid implant, or any implanted electronic device
• Patients with metallic device such as a stent, bone plate or bone screw implanted at or near their neck
• Patients with an active implantable medical device, such as a pacemaker, hearing aid implant, or any implanted electronic device
• Patients with metallic device such as a stent, bone plate or bone screw implanted at or near their neck
• Patients who are using another device at the same time (e.g., transcutaneous electrical nerve stimulation (TENS) Unit, muscle stimulator) or any portable electronic device (e.g., mobile phone).

Participant and outcomes assessor will not know which treatment arm the subject has been assigned to during the study.