ABVN Phase 2 - Ear Stimulation

The vagus nerve is a nerve that controls many bodily functions, including stomach function. Investigators hope that electrically stimulating the nerve around the external ear will also stimulate the internal vagus nerve. If it does, then investigators hope that this may lead to additional treatment options for patients with nausea and vomiting and disordered stomach function. The overall purpose of the ABVN Phase 2 grant is to expand on previous work evaluating the effects of noninvasive stimulation on vagal nerve function. This will be accomplished through several independent, but related, studies. In this study, investigators will evaluate the effect of transcutaneous electrical stimulation of the vagus nerve on vagal nerve CNAPs and gastric hormones in healthy subjects and in subjects with gastroparesis.

Inclusion Criteria healthy volunteers * Healthy volunteers with no gastric symptoms or conditions (except due to COVID 19) * Aged 18-80 years * Willing to have electrodes placed in the external ear * Willing to have 1 tablespoon (15 ml) of blood drawn at 3 time points Exclusion Criteria healthy volunteers: * Unable to provide consent * Pregnant females * Prisoners Inclusion Criteria gastroparesis subjects * Have a formal diagnosis of gastroparesis or are seeing the GI physician for symptoms related to gastroparesis * Aged 18-80 years * Willing to have electrodes placed in the external ear * Willing to have 1 tablespoon (15 ml) of blood drawn at 3 time points Exclusion Criteria gastroparesis subjects: * Unable to provide consent * Have an implanted gastric stimulator * Pregnant females * Prisoners