Obstructive Sleep Apnea (OSA)NCT07466888
Effects of Frequency Adjustment in Functional Electrical Stimulation on Genioglossus Muscle Activity
A study testing Functional Electrical Stimulation Device in people with Obstructive Sleep Apnea (OSA) and Snoring, run by Seoul National University Bundang Hospital at 1 site in South Korea.
Trial summary
This single-group interventional study investigates the safety and physiologic effects of functional electrical stimulation (FES) applied to the tongue and submental muscles in adults at high risk for sleep apnea. Read more about this study
- Who is it for?
- Ages 19 years and olderHealthy volunteers can take part
- Conditions the study is for
- Obstructive Sleep Apnea (OSA), Snoring
- What is being tested?
- Functional Electrical Stimulation Device
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 1 siteSouth Korea
- Study dates
- 6 Jan 2026to Apr 2026
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adults aged 19 years or older
- STOP questionnaire score ≥ 2
- Able to read and write in Korean
- Voluntarily provides written informed consent to participate in the study
Who cannot join
- Refusal to undergo study procedures or failure to provide informed consent
- Cognitive impairment or psychiatric disorders that interfere with the ability to follow study instructions
- Pregnant or breastfeeding women
- Known allergy or hypersensitivity to electrical stimulation pads or related materials (e.g., silicone, polypropylene, polyethylene)
- Skin conditions preventing application of electrical stimulation (e.g., hypersensitive skin)
- Medical conditions considered unsuitable for participation by the investigator (e.g., epilepsy, malignant tumor, high fever, diabetes mellitus, use of anticoagulants, phlebitis, thrombophlebitis, hemophilia)
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- Infectious disease or local conditions at the stimulation site (e.g., inflammation, wounds, abscess, edema)
- Known cardiac disease or presence of a cardiac pacemaker or implanted electrical stimulation device
- History of surgery involving the submental area or upper airway region
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Hyunjin KIM contact
South Korea1 site, 1 recruiting
- Recruiting
Seoul National University Bundang Hospital
Gyeonggi-do, Seongnam-si, 463-707
Hyunjin KIM, +82-10-9974-7152, RQ300@snubh.org
About this study
This single-group interventional study investigates the safety and physiologic effects of functional electrical stimulation (FES) applied to the tongue and submental muscles in adults at high risk for sleep apnea. Participants will receive five stimulation frequencies (15, 25, 35, 45, and 75 Hz) in randomized order during a single visit. Ultrasound and tongue pressure (IOPI) measurements, as well as subjective assessments of discomfort and perceived effects, will be conducted before, during, and after stimulation. The primary objective is to evaluate changes in muscle thickness, length, and tongue strength across different stimulation frequencies. Secondary objectives include assessing participant discomfort, safety, and subjective treatment effects.
Read the detailed description
Reduced tone and weakness of the genioglossus muscle are critical factors in the pathophysiology of obstructive sleep apnea (OSA). In addition to the genioglossus, other upper airway-related muscles, including the thyrohyoid and additional infrahyoid muscles, contribute to airway stability. These muscles differ in anatomical depth from the skin surface and in muscle thickness, which necessitates differentiated electrical stimulation approaches to ensure selective activation and safety.This clinical trial is designed to evaluate the safety and efficacy of functional electrical stimulation (FES) applied to the genioglossus muscle with modulation of stimulation frequency. The study aims to determine whether frequency adjustment influences muscle morphology and functional outcomes.The primary objective is to assess frequency-dependent changes in muscle length and thickness using ultrasonography, as well as differences in tongue strength measured by the Iowa Oral Performance Instrument (IOPI) before and after electrical stimulation.The secondary objective is to evaluate discomfort, safety, and subjective treatment effects through questionnaires administered before and after the electrical stimulation intervention.
- Conditions
- Obstructive Sleep Apnea (OSA), Snoring
- Being tested
- Functional Electrical Stimulation Device
- Keywords
- Obstructive Sleep Apnea (OSA), Snoring, FES
- Medical subject headings
- Sleep Apnea, Obstructive, Snoring
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Functional Electrical Stimulation DeviceDevice
A functional electrical stimulation device is applied to the submental region using surface adhesive electrodes. Stimulation is delivered at five different frequencies (15, 25, 35, 45, and 75 Hz) in randomized sequence during a single study visit. Each frequency is administered within the same session to evaluate immediate physiologic responses of the tongue muscles. Participants are blinded to the stimulation frequency applied during each condition.
| Study group | Role | What they receive |
|---|---|---|
| Multi-frequency Functional Electrical Stimulation | Experimental | All participants receive a single-session multi-frequency functional electrical stimulation protocol (15-75 Hz) applied in randomized order. Ultrasound and tongue pressure (IOPI) measurements are performed before and after stimulation, while subjective assessments of discomfort and perceived effects are collected during each stimulation frequency. Participants are blinded to stimulation frequency. Receives: Device: Functional Electrical Stimulation Device |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in genioglossus muscle thickness measured by ultrasonography
The thickness of the genioglossus muscle is measured using ultrasonography before and immediately after electrical stimulation at each frequency (15, 25, 35, 45, and 75 Hz) during a single study visit.
Measured: Before and immediately after stimulation at each frequency during a single study visit (~1 hour)
Change in genioglossus muscle length measured by ultrasonography
The length of the genioglossus muscle is measured using ultrasonography before and immediately after electrical stimulation at each frequency (15, 25, 35, 45, and 75 Hz) during a single study visit.
Measured: Before and immediately after stimulation at each frequency during a single study visit (~1 hour)
Change in tongue strength measured by the Iowa Oral Performance Instrument (IOPI)
Tongue strength is measured using the Iowa Oral Performance Instrument (IOPI) in kilopascals (kPa) before electrical stimulation and immediately after completion of all frequency conditions during a single study visit (~1 hour). IOPI scores range from 0 kPa (no measurable pressure) to approximately 70 kPa (maximum tongue strength), with higher scores indicating greater tongue strength.
Measured: Before stimulation and immediately after completion of all frequency conditions during a single study visit (~1 hour)
Secondary outcomes (1)
Participant-reported discomfort associated with electrical stimulation
Participant discomfort is assessed using a 1-5 Likert scale questionnaire during each stimulation frequency and immediately after completion of all frequency conditions during the study visit (~1 hour). Scale interpretation: 1 = very uncomfortable, 2 = uncomfortable, 3 = neutral, 4 = comfortable, 5 = very comfortable. Higher scores indicate greater comfort.
Measured: During each stimulation frequency and immediately after completion of all frequency conditions during a single study visit (~1 hour)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Mar 2026
- Study start6 Jan 2026
- Primary completionMar 2026 (estimated)
- Study completionApr 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Obstructive Sleep Apnea (OSA)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is a single-group interventional study in which all participants undergo a multi-frequency functional electrical stimulation protocol during a single study visit. The protocol includes five stimulation frequencies (15, 25, 35, 45, and 75 Hz) applied in randomized order within the same session. Outcomes are assessed before, during, and immediately after stimulation to evaluate within-subject physiologic responses.
- Masking
- None (open label)
- Enrolment
- 28 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Seoul National University Bundang Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- National Research Foundation of Korea
- Responsible party
- Principal investigator, JeeHyun Suh, Seoul National University Bundang Hospital
- Investigators
- Jee Hyun Suh, M.D., Ph.D., Principal investigator, Seoul National University Bundang Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07466888
- Sponsor's protocol ID
- B-2506-978-001
- Status last verified
- Mar 2026
- First submitted
- 24 Feb 2026
- Last updated
- 12 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No