The purpose of this study is to find out if manual stimulation of the vagus nerve is possible. The vagus nerve is a largely-internal nerve that controls many bodily functions, including stomach function. The hope is that electrically stimulating the nerve around the external ear will also stimulate the internal vagus nerve.

The purpose of this study is to find out if it is possible to gain access to the vagus nerve which is largely an internal nerve that controls stomach function. The hope is to gain access to the internal vagus nerve by electrically stimulating the nerve around the external ear. If this is possible to do this then there is hope that this will help the treatment of patients with nausea and vomiting and disordered stomach function. Healthy subjects and subjects with gastroparesis will be recruited. Subjects will undergo transcutaneous stimulation of the auricular branch of the vagus nerve and also undergo blood draw before, after stimulation and later a third draw after a period of no stimulation. Healthy subjects will also undergo vagal maneuver using the Multi Array Electrodes (MEA). Subjects will also complete health history questionnaires.

Inclusion Criteria:

• Volunteers with no GI symptoms
• Ages 18-80
• Undergoing VNS Therapy as part of clinical treatment for focal or partial epilepsy or seizure
• Willing to have MEA electrodes placed on the neck and bipolar electrodes placed on chest and stomach

Exclusion Criteria:

• Unable to provide consent
• Having gastric motility issues (not due to COVID 19) as determined by the PI or Sub I
• Taking medications affecting gastric motility
• Pregnant females
• Prisoners