RecruitingPhase 3Device studyNon-invasive Vagal Nerve Stimulation in Opioid Use Disorders UH3This study is being done to answer the question: what is the effect of Vagal Nerve Stimulation (VNS) dosing on opioid withdrawal responses in individuals with a history of Opioid Use Disorders (OUDs)? Eligible participants will be in the study for one week in an inpatient research hospital stay, have an MRI scan, and have a follow-up call 1-3 months after their inpatient stay. Participants will complete several psychiatric questionnaires/interviews, physiological monitoring with several devices, brain imaging, and VNS testing.