An interventional study of Pulsetto FIT™ - Sham tcVNS and Pulsetto FIT™ - tcVNS 10 Hz in Vagus Nerve Stimulation, Autonomic Nervous System and Heart Rate, sponsored by SEFA HAKTAN HATIK. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 30 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-10.
Sponsored by SEFA HAKTAN HATIK · Not applicable, Interventional, and Basic science
This randomized, sham-controlled, crossover study investigates the acute autonomic effects of transcutaneous cervical vagus nerve stimulation (tcVNS) applied at five different frequencies (0 Hz/sham, 10 Hz, 25 Hz, 50 Hz, 100 Hz) in healthy adults. The primary objective is to determine how stimulation frequency modulates heart rate variability (HRV), blood pressure, and respiratory rate. The study aims to establish a frequency-specific dose-response model using validated physiological measurements.
Transcutaneous cervical vagus nerve stimulation (tcVNS) is a non-invasive neuromodulation technique capable of activating afferent vagal pathways projecting to autonomic brainstem nuclei. Although previous studies demonstrate tcVNS-related modulation of autonomic functions, the frequency-response relationship remains insufficiently explored.
This crossover trial randomizes participants to receive five stimulation conditions (sham, 10 Hz, 25 Hz, 50 Hz, 100 Hz) in counterbalanced order. HRV (Polar H10), blood pressure (Omron), and respiratory rate (Kinovea-based thoracoabdominal video tracking) are collected pre- and post-stimulation. Washout between sessions is ≥48 hours.
The study provides one of the first systematic evaluations of frequency-dependent tcVNS effects in healthy adults.
SEFA HAKTAN HATIK is the lead sponsor of 14 studies on the registry; 8 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Intervention Type: Pulsetto FIT™ tcVNS Device Intervention Name: Sham tcVNS Description: Device placed on bilateral cervical region; no electrical current delivered. Dose: 10 minutes
Device: Pulsetto FIT™ - Sham tcVNS
Intervention Type:Pulsetto FIT™ tcVNS Device Intervention Name: tcVNS (10 Hz) Description: Bilateral cervical stimulation at 10 Hz, 250 μs pulse width. Duration: 10 minutes
Device: Pulsetto FIT™ - tcVNS 10 Hz
Intervention Type:Pulsetto FIT™ tcVNS Device Intervention Name: tcVNS (25 Hz) Description: Bilateral cervical stimulation at 25 Hz, 250 μs pulse width. Duration: 10 minutes
Device: Pulsetto FIT™ - tcVNS 25 Hz
Intervention Type:Pulsetto FIT™ tcVNS Device Intervention Name: tcVNS (50 Hz) Description: Bilateral cervical stimulation at 50 Hz, 250 μs pulse width. Duration: 10 minutes
Device: Pulsetto FIT™ - tcVNS 50 Hz
Intervention Type:Pulsetto FIT™ tcVNS Device Intervention Name: tcVNS (100 Hz) Description: Bilateral cervical stimulation at 100 Hz, 250 μs pulse width. Duration: 10 minutes
Device: Pulsetto FIT™ - tcVNS 100 Hz
The Pulsetto FIT™ device is placed bilaterally on the cervical region (posterior margin of the sternocleidomastoid muscle). In the sham condition, the device displays normal operational lights but delivers no electrical stimulation (0 Hz; inactive mode). This condition is used for blinding and as the control comparator. Dose: 10 minutes
Bilateral transcutaneous cervical vagus nerve stimulation delivered via the Pulsetto FIT™ device at 10 Hz, 250 µs pulse width. Current intensity adjusted to a mild, non-painful tingling sensation, individualized for each participant. Dose: 10 minutes
Bilateral tcVNS using the Pulsetto FIT™ device at 25 Hz, 250 µs pulse width. Stimulation intensity set at a comfortable sensory level. Dose: 10 minutes
Bilateral cervical vagus nerve stimulation via Pulsetto FIT™ at 50 Hz, 250 µs pulse width. Intensity adjusted to a tolerable sensory level without discomfort. Dose: 10 minutes
Bilateral tcVNS delivered with the Pulsetto FIT™ device at 100 Hz, 250 µs pulse width. Highest stimulation frequency used in this protocol; current intensity individualized per participant comfort. Dose: 10 minutes
Heart Rate Variability (HRV) Changes (ΔRMSSD, ΔHF, ΔLF/HF)
HRV is recorded using a validated high-resolution heart rate monitor (Polar H10) during a 5-minute resting baseline (T0) and a 5-minute post-stimulation period (T2). The following time- and frequency-domain parameters are analyzed: RMSSD, HF (ms²), and LF/HF ratio. Artefact correction is performed using standard HRV processing methods. Acute autonomic response is quantified by calculating change scores (Δ = post-pre) for each stimulation frequency.
Time frame: Pre- vs Post-stimulation (5-min segments)(5-minute baseline, 5-minute stimulation, 5-minute post period)
Blood Pressure (SBP, DBP, MAP)
Two readings are taken at each time point from the right arm with a validated automatic sphygmomanometer, and the average systolic, diastolic, and mean arterial pressure values are used for analysis. Changes are calculated as post-pre (Δ values) to assess the acute physiological effect of each stimulation frequency..
Time frame: Pre- vs Post-stimulation (5-minute baseline, 5-minute stimulation, 5-minute post period)
Respiratory Rate (breaths per minute)
Respiratory rate is assessed by video-based thoracoabdominal motion tracking at baseline (T0) and after stimulation (T2). Videos are analyzed using Kinovea motion-tracking software, and a 1-minute stable segment is used to determine breaths per minute by counting inspiratory peaks. Respiratory changes are expressed as Δ values (post-pre) to account for individual differences and improve HRV interpretability.Respiratory rate is assessed by video-based thoracoabdominal motion tracking at baseline (T0) and after stimulation (T2). Videos are analyzed using Kinovea motion-tracking software, and a 1-minute stable segment is used to determine breaths per minute by counting inspiratory peaks. Respiratory changes are expressed as Δ values (post-pre) to account for individual differences and improve HRV interpretability.
Time frame: Pre- vs Post-stimulation (5-minute video segments) (5-minute baseline, 5-minute stimulation, 5-minute post period)
Discomfort Level (Visual Analog Scale, 0-10)
Participants report their perceived discomfort level at baseline (T0) and immediately after stimulation (T2) using a 0-10 Visual Analog Scale (VAS). The scale captures any sensory discomfort associated with tcVNS. Changes are calculated by subtracting the pre-stimulation score from the post-stimulation score (ΔVAS).
Time frame: Pre- vs Post-stimulation (5-minute baseline, 5-minute stimulation, 5-minute post period)
Plan to share: No — Individual participant data will not be shared because the study includes physiological recordings (HRV, blood pressure, respiratory videos) that cannot be fully anonymized. Data sharing may pose a risk of indirect identification. Only aggregated results will be reported in publications and presentations. IPD Sharing Time Frame: Not applicable. IPD Sharing Access Criteria: Not applicable.
Start is estimated for Dec 2025; primary completion for Jan 2026, 1 month later.
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