Healthy
Conditions
Brief summary
The purpose of this research study is to investigate the effects of different forms of a gentle form of electrical stimulation applied to the ear, known as transcutaneous auricular vagus nerve stimulation (taVNS). The research team is interested in how the different forms affect comfort and tolerability, as well as how well it works.
Interventions
DEVICEBiphasic transcutaneous auricular vagus nerve stimulation
Transauricular vagus nerve stimulation (taVNS) is a simple technique in which small surface electrodes are placed over the skin of the ear that are thought to be innervated by the auricular branch of the vagus nerve (ABVN). Participants in this group will first receive taVNS with a biphasic current, continuous at 25 Hz, for 1 hour, in-person.
DEVICEMonophasic transcutaneous auricular vagus nerve stimulation
Transauricular vagus nerve stimulation (taVNS) is a simple technique in which small surface electrodes are placed over the skin of the ear that are thought to be innervated by the auricular branch of the vagus nerve (ABVN). Participants in this group will first receive taVNS with a monophasic current, with a 50% duty cycle at 25 Hz, for 1-hour, in-person.
Sponsors
University of Miami
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Investigator)
Masking description
Participants will be blinded to which protocol they are receiving during data collection. The investigator responsible for processing HRV data will be blinded to group assignment, and investigators will be blinded to group assignment when conducting qualitative data analysis.
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
1. between the ages of 18-80 years 2. English speaking (must be able to consent and complete the interviews in English)
Exclusion criteria
1. chronic pain (average intensity \>2/10 on 0-10 scale, for longer than 3 months) 2. acute pain of intensity greater than 3/10 3. chronic inflammatory conditions that are poorly controlled (e.g., diabetes, autoimmune disease) 4. any unstable medical condition or medical contraindication to moderate physical exertion (e.g., unstable angina or cardiac arrythmia) 5. pregnancy 6. currently taking Buprenorphine or recently stopped taking (within 1 month) 7. presence of cognitive impairment or language barrier that impairs full autonomy in the consent process or in the ability to participate in detailed interviews 8. implants in the head or neck, cochlear implants, or pacemaker 9. head or neck metastasis or recent ear trauma 10. history of epilepsy 11. history of autonomic nervous system dysfunction (e.g., postural orthostatic tachycardia syndrome).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Tolerability Measured by Tolerability Questionnaire | Up to 3 hours | Tolerability will be assessed with a questionnaire with scores ranging from 0 (no discomfort) to 10 (worst pain imaginable) for comfort. |
| Tolerability Measured by Self Report | Up to 3 hours | Tolerability will be assessed by self-report using semi-structured interviews conducted at the end of each study visit. Participants will report whether they experienced mild pain during each transcutaneous auricular vagus nerve stimulation (taVNS) protocol. The outcome measure is the count of participants who reported mild pain, as collected during interviews conducted at the end of each visit. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Heart Rate Variability (HRV) | Baseline and up to 3 hours | Heart rate variability (HRV) will be measured using an H10 chest strap device and expressed in milliseconds. Values after stimulation will be subtracted from baseline values; thus, a positive number will indicate an increase in HRV post taVNS. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORMarlon Wong, PT, PhD
University of Miami
Participant flow
Recruitment details
Only healthy individuals (no patients) will be recruited for this study. All recruitment will be in accordance with the UM Human Subjects and Research Office guidelines. We will only recruit participants via flyers. Participants will be recruited from the University of Miami Department of Physical Therapy, The University of Miami Student Complex, and The University of Miami Health and Wellness Centers, and the community.
Pre-assignment details
All participants will receive both taVNS protocols in random order. Thus, half of the participants will receive Protocol-1 first followed by Protocol-2, and the other half will receive Protocol-2 first followed by Protocol-1.
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 27.50 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 5 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 18 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants |
| Race (NIH/OMB) White | 12 Participants |
| Sex: Female, Male Female | 9 Participants |
| Sex: Female, Male Male | 8 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 16 | 0 / 14 |
| other Total, other adverse events | 0 / 16 | 0 / 14 |
| serious Total, serious adverse events | 0 / 16 | 0 / 14 |
Outcome results
None listed