Effect of Transcutaneous Auricular Vagus Nerve Stimulation on Plasma Insulin Levels (taVNS)
Thomas Nowak, MD
Primary Investigator
Brief description of study
The purpose of this study is to test whether electrically stimulating the nerve around the external ear will also stimulate the internal vagus nerve and influence the levels of substances in your body related to insulin production. We hope that the findings from this study will help our treatment of patients with nausea and vomiting and disordered stomach function, as well as patients with diabetes.
Detailed description of study
- This study includes the collection of blood and the use of a butterfly needle.
- This study uses an electrocardiogram (ECG), and you will have ECG electrodes attached to your body.
- This study includes the use of a Transcutaneous electrical nerve stimulation (TENS). TENS is a therapeutic technique that uses a small, battery-operated device to send mild electrical currents to your skin.
- You will have to lay on your back for at least 90 minutes.
• You will be asked to not eat or drink anything for 8-10 hours before the visit. You may drink a small amount of water to take medications.
• You will be asked to refrain from using your phone, device, or anything else that may induce movement and alter the results of the recordings.
• Three ECG (electrocardiogram) electrodes will also be placed on your chest and/or arms or legs to record the electrical activity of your heart.
• You will be asked to lay down facing upward and additonal ECG electrodes will be placed on your neck near the carotid artery, the large blood vessel that carries blood from the heart to your head and face.
• A nurse will then come and place a butterfly needle in one of the veins in your arm (see below).
This process is so that you only have to go through 1 needle stick for the 3 blood draws.
• Your left ear will be swabbed with an alcohol wipe so that the adhesive will stay in place, and then a TENS unit electrode will be placed on the inside of the outer ear (see below).
• We will record a 20 minute baseline ECG recording, followed by the first 5ml blood draw.
• After the first blood draw, the TENS unit will be turned ON, and mild electric current will delivered over 40 minutes. The pulses will be delivered in a cycle of 2 seconds on and 3 seconds off. You will probably feel some tingling at the site when the TENS unit is turned on. If you feel more than minor discomfort the TENS unit will be adjusted to minimize the discomfort.
• At the end of the 40 minutes, a second sample of blood will be drawn.
Eligibility of study
You may be eligible for this study if you meet the following criteria:
- Conditions: Healthy
-
Age: 18 years - 70 years
-
Gender: All
1. Healthy volunteers
2. Aged 18-70 years.
3. Willing to have ECG electrodes placed on their neck and chest areas.
4. Willing to have electrodes placed in the external ear.
5. Willing to have an indwelling catheter placed to avoid multiple sticks for blood draw.
Exclusion Criteria
1. Unable to provide consent.
2. Diabetes diagnosis per patient report
3. Having known allergies to adhesive on electrode pads or bandages
4. Self -report of diagnosis of gastric motility issues
5. Taking any medications that may affect gastric motility or cardiac variability, ie alpha or beta blockers for hypertension.
6. Pregnant females
7. Those unwilling to have the taVNS device placed in their ear.
8. Those unwilling to consent to a blood draw.
9. Prisoners
