Effect of Recording Duration on Heart Rate Variability During taVNS

NCT07526415 | Not Yet Recruiting

• 1 other identifier: TAVNS6
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to evaluate how different heart rate variability (HRV) recording durations reflect autonomic nervous system responses during transcutaneous auricular vagus nerve stimulation (taVNS) in healthy adults. In a randomized, sham-controlled crossover design, participants will attend two separate sessions and receive both active taVNS and sham stimulation in randomized order. During each session, a continuous 10-minute HRV recording will be obtained, and 1-minute, 5-minute, and 10-minute analysis windows will be compared. Blood pressure and pulse will also be measured before and after stimulation. The study will investigate whether shorter or longer HRV recording durations provide results comparable to the standard 5-minute recording and which duration most reliably detects autonomic changes during taVNS.

Conditions

Healthy Volunteers

Keywords

Transcutaneous Auricular Vagus Nerve Stimulation; taVNS; Autonomic Nervous System

Outcome Measures

Primary Outcomes (1)

• Difference in 5-minute lnRMSSD During Active taVNS Compared With Sham Stimulation

  The primary outcome is the between-condition difference in 5-minute heart rate variability, assessed by lnRMSSD derived from the continuous RR interval recording obtained during the 10-minute intervention period. The 5-minute analysis window is the prespecified standard short-term HRV measure used to compare active transcutaneous auricular vagus nerve stimulation with sham stimulation.

  During the 10-minute intervention period at each study session

Secondary Outcomes (5)

• Agreement Between 1-minute and 5-minute HRV Measurements During Active taVNS

  During the 10-minute intervention period at each active taVNS session

• Comparison of 10-minute and 5-minute HRV Measurements During Active taVNS

  During the 10-minute intervention period at each active taVNS session

• Effect of Recording Duration on HRV Differences Between Active taVNS and Sham Stimulation

  During the 10-minute intervention period at each study session

• Change in Systolic and Diastolic Blood Pressure After Active taVNS Compared With Sham Stimulation

  Immediately before and immediately after each 10-minute intervention session

• Change in Pulse Rate After Active taVNS Compared With Sham Stimulation

  Immediately before and immediately after each 10-minute intervention session

Study Arms (2)

taVNS First

EXPERIMENTAL

Participants assigned to this sequence will receive active transcutaneous auricular vagus nerve stimulation (taVNS) during the first session and sham stimulation during the second session, with a 48- to 72-hour washout period between sessions.

Device: Transcutaneous Auricular Vagus Nerve Stimulation

Sham First

SHAM COMPARATOR

Participants assigned to this arm will receive sham stimulation during the first session and active transcutaneous auricular vagus nerve stimulation (taVNS) during the second session, with a 48- to 72-hour washout period between sessions.

Device: Sham Stimulation

Interventions

Sham Stimulation DEVICE

Sham stimulation will be delivered for 10 minutes using the same transcutaneous stimulation device and similar stimulation settings as the active intervention, but the stimulation will be applied to a non-vagal ear region, such as the earlobe or helix, to minimize physiologic vagal effects while maintaining similar sensory input. Heart rate variability will be recorded continuously during the intervention.

Also known as: Sham taVNS

Sham First

Transcutaneous Auricular Vagus Nerve Stimulation DEVICE

Active transcutaneous auricular vagus nerve stimulation will be applied bilaterally to the cymba conchae region of the ear using a transcutaneous stimulation device. Stimulation will be delivered for 10 minutes with a frequency of 25 Hz, a pulse width of 200 to 300 microseconds, and an individually adjusted intensity that is clearly perceptible but not painful. Heart rate variability will be recorded continuously during the intervention.

Also known as: taVNS

taVNS First

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy volunteers aged 18 to 40 years
• Able and willing to provide informed consent
• Able to tolerate active transcutaneous auricular vagus nerve stimulation and sham stimulation
• Able to comply with study instructions, including restrictions related to caffeine, nicotine, and heavy exercise before assessment
• No condition preventing heart rate variability, blood pressure, or pulse measurements

You may not qualify if:

• Diagnosed cardiovascular disease, arrhythmia, or pacemaker use
• History of neurologic disease that may affect autonomic nervous system function
• Regular use of medications that may affect heart rate variability or autonomic responses, including beta blockers, antiarrhythmics, or anticholinergic drugs
• Active ear infection, dermatologic lesion, or any ear condition that may interfere with stimulation
• Marked pain, discomfort, or intolerance during stimulation
• Acute infection, fever, or other acute health problem on the measurement day
• Heart rate variability data that cannot be evaluated because of excessive motion artifact

Sponsors & Collaborators

• Sinop University: lead

Study Sites (1)

Artvin Coruh University, Artvin Vocational School, Disabled Care and Rehabilitation Laboratory, Artvin,

Artvin, Turkey (Türkiye)

Location

Related Publications (4)

• Frangos E, Ellrich J, Komisaruk BR. Non-invasive Access to the Vagus Nerve Central Projections via Electrical Stimulation of the External Ear: fMRI Evidence in Humans. Brain Stimul. 2015 May-Jun;8(3):624-36. doi: 10.1016/j.brs.2014.11.018. Epub 2014 Dec 6.

  PMID: 25573069 BACKGROUND

• Shaffer F, Ginsberg JP. An Overview of Heart Rate Variability Metrics and Norms. Front Public Health. 2017 Sep 28;5:258. doi: 10.3389/fpubh.2017.00258. eCollection 2017.

  PMID: 29034226 BACKGROUND

• Clancy JA, Mary DA, Witte KK, Greenwood JP, Deuchars SA, Deuchars J. Non-invasive vagus nerve stimulation in healthy humans reduces sympathetic nerve activity. Brain Stimul. 2014 Nov-Dec;7(6):871-7. doi: 10.1016/j.brs.2014.07.031. Epub 2014 Jul 16.

  PMID: 25164906 BACKGROUND

• Peuker ET, Filler TJ. The nerve supply of the human auricle. Clin Anat. 2002 Jan;15(1):35-7. doi: 10.1002/ca.1089.

  PMID: 11835542 BACKGROUND

Central Study Contacts

Sefa Haktan Hatık, PhD

CONTACT

+90 368 271 55 28; haktanhtk@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The study will use partial blinding. The investigator performing physiologic measurements and the researcher responsible for statistical analysis will be blinded to intervention assignment. Data will be analyzed using coded datasets, and group identities will be revealed only after completion of the analyses. The researcher delivering the intervention cannot be blinded because active taVNS and sham stimulation require different application sites.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant professor

Model Details: A randomized, sham-controlled crossover design will be used. Each participant will attend two separate sessions and receive both active transcutaneous auricular vagus nerve stimulation (taVNS) and sham stimulation in randomized order, with a 48- to 72-hour washout period between sessions. Continuous 10-minute heart rate variability recordings will be obtained during each intervention session.

Study Record Dates

• First Submitted: April 6, 2026
• First Posted: April 13, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): September 15, 2026
• Last Updated: April 16, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)