Noninvasive Neurostimulation of the Vagus Nerve for the Relief of Acute Bronchoconstriction Due to Asthma

Inclusion Criteria: 1. Is between the ages of 18 and 70 years. 2. Has been admitted to an emergency care facility with a working diagnosis of bronchoconstriction due to asthma. 3. Has an FEV1\<60% predicted. 4. Is available and willing to return for an office visit at 7 days and participate in a 30-day telephone call from time of discharge from the ED. 5. Is able to give written Informed Consent, or his/her legally authorized representative is available to give written Informed Consent. Exclusion Criteria: 1. Has a history of lung cancer, chronic obstructive pulmonary disease (COPD), or other co-morbidity due to irreversible narrowing of the airways. 2. Is at risk of imminent respiratory collapse: * Lung Function: FEV1 \< 25% predicted * Signs and symptoms of extreme respiratory distress at rest, such as accessory muscle use, chest retraction * Consciousness State: Drowsy, confused * Rapid deterioration in respiratory status (sudden change in respiratory rate, decrease in oxygen saturation, change in consciousness, etc). 3. Has an abscess or other infection or lesion (including lymphadenopathy) at the therapy head placement site. 4. Has known or suspected atherosclerotic cardiovascular disease, carotid artery disease (e.g. bruits or history of TIA or CVA) or congestive heart failure (CHF). 5. Has suspected or confirmed sepsis. 6. Has a clinically significant irregular heart rate or rhythm. 7. Clinically significant changes in blood pressure or is receiving pressors to maintain blood pressure. 8. Is currently implanted with an electrical and/or neurostimulator device, including but not limited to cardiac pacemaker, vagal neurostimulator, deep brain stimulator, spinal stimulator, bone growth stimulator, or cochlear implant. 9. Has a history of carotid endarterectomy or vascular neck surgery on the right side. 10. Has been implanted with metal cervical spine hardware. 11. Has a condition that would interfere with VAS Dyspnea self-assessment. 12. Is pregnant. 13. Is participating in any other therapeutic clinical investigation or has participated in a clinical trial in the preceding 30 days. 14. Belongs to a vulnerable population or has any condition such that his or her ability to provide informed consent, comply with follow-up requirements, or provide self-assessments is compromised (e.g., homeless, developmentally disabled, prisoner).