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NCT Number: NCT07420530

Respiratory and Real-time Dynamics in Exercise-Induced Paradoxical Vocal Fold Motion

The overall objectives of the proposed research are to:

1. Evaluate the diagnostic validity of a novel mechano-acoustic signatures of task-characteristic activity during symptomatic and asymptomatic breathing in Exercise-Induced Laryngeal Obstruction (EILO) patients with the use of a novel miniature, soft wearable skin-mounted device, 2. Identify the mechanism/s of paradoxical respiratory control in EILO by quantifying the relationship between pulmonary mechanics, partial pressure of carbon dioxide (PCO2) maintenance, and vocal fold aperture prior to and during symptomatic and asymptomatic exercise ventilation, and 3. Identify unique biophysiological factors contributing to EILO among exercisers with and without EILO. Findings will be highly novel and clinically significant for early identification and management of EILO.

For the study there are three separate visits:

1. Free running with the device on the neck 2. Exercise treadmill study 3. Undergoing MRI (Magnetic Resonance Imaging) of the vocal tract.

Recruiting

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Key information

Age range

18 year–26 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

Indiana University

Bloomington, Indiana, 47401, United States

Location status: Recruiting

Location contact

Rita Patel

CONTACT

[email protected]

812-855-3886

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

for Exercise-Induced Laryngeal Obstruction (EILO):

  • Physically active >2.5 hours per week
  • Patients with EILO, as diagnosed by routine clinical examination by physician and/or speech language pathologist
  • Age range of 18-26 years
  • Greater difficulty breathing inside compared to out and difficulty breathing which is exacerbated at peak exercise and stops 1-5 minutes after exercise
  • Score of 7 or higher on the Dyspnea Index, which is a validated instrument to capture participant self-report of upper airway dyspnea symptoms.
  • Classified as low risk, based on the modified Physical Activity Readiness Questionnaire (PAR-Q) questionnaire, body mass index, and non-smoking status
  • Negative history of voice disorders, self-report of cognitive difficulties, asthma or other lung disease, cardiac disease, serious orthopedic injuries, current uncontrolled hypertension, illicit drug use, seizure/epilepsy, claustrophobia, use of beta blockers.
  • No metallic, mechanical or magnetic implants such as cardiac devices, cochlear, or other non-removable ear implants, any prosthesis, stents, deep brain stimulator, etc.

Inclusion criteria

for Controls

  • Physically active >2.5 hours per week
  • Age range of 18-26 years
  • Classified as low risk, based on the modified PAR-Q questionnaire, body mass index, and non-smoking status
  • Negative history of voice disorders, self-report of cognitive difficulties, asthma or other lung disease, cardiac disease, serious orthopedic injuries, current uncontrolled hypertension, illicit drug use, seizure/epilepsy, claustrophobia, use of beta blockers.
  • No metallic, mechanical or magnetic implants such as cardiac devices, cochlear, or other non-removable ear implants, any prosthesis, stents, deep brain stimulator, etc.

Exclusion criteria

for EILO:

  • Individuals older than 26 years and younger than 18 years of age.
  • Women who are pregnant or could possibly be pregnant.
  • BMI > 25 kg/m2
  • A 'yes' answer to any of the 14 questions on the PAR-Q pre-participation questionnaire
  • Current smoker
  • Positive history of voice disorders, self-report of cognitive difficulties, asthma or other lung disease, cardiac disease, serious orthopedic injuries, current uncontrolled hypertension, illicit drug use, seizure/epilepsy, claustrophobia, use of beta blockers.
  • Presence of metallic, mechanical or magnetic implants such as cardiac devices, cochlear, or other non-removable ear implants, any prosthesis, stents, deep brain stimulator, etc.
  • Do not report the following: Greater difficulty breathing inside compared to out and difficulty breathing which is exacerbated at peak exercise and stops 1-5 minutes after exercise

Exclusion criteria

for Controls

  • Individuals older than 26 years and younger than 18 years of age.
  • Women who are pregnant or could possibly be pregnant.
  • BMI > 25 kg/m2
  • A 'yes' answer to any of the 14 questions on the PAR-Q pre-participation questionnaire
  • Current smoker
  • Positive history of voice disorders, self-report of cognitive difficulties, asthma or other lung disease, cardiac disease, serious orthopedic injuries, current uncontrolled hypertension, illicit drug use, seizure/epilepsy, claustrophobia, use of beta blockers.
  • Presence of metallic, mechanical or magnetic implants such as cardiac devices, cochlear, or other non-removable ear implants, any prosthesis, stents, deep brain stimulator, etc.
  • Significant acute or chronic medical, neurologic, or illness in the patient that, in the judgment of the Principal Investigator, could compromise subject safety, limit the ability to complete the study, and/or compromise the objectives of the study

Treatment and study plan

Carbon Dioxide

Drug

Breathing Hypercapnic Gas (10% CO2 (carbon dioxide) and 21%O2 (oxygen), balance N210% (nitrogen))

Breathing treatment

Behavioral

Random Assignment to breathing conditions (rest breathing, rapid breathing, quick nasal sniff, pursed lip breathing), in a single blinded randomized design

Primary outcomes

  1. Device measurements from real time running

    Time frame: Baseline and Periprocedural

    Muscle activation of cricothyroid/sternohyoid muscle measured via customized surface electromyography amplifier

  2. Device measurements from real time running

    Time frame: Baseline and Periprocedural

    Normalized amplitude (100% of maximum voluntary contraction) Burst duration (milliseconds) prior to and during Exercise-Induced Laryngeal Obstruction event of laryngeal closure.

  3. Device measurements from real time running

    Time frame: Baseline and Perioprocedural

    Exercise-Induced Laryngeal Obstruction signature detected via ultra-low noise micro-electromechanical (MEMS) microphone amplitude (dB) prior to and during EILO. EILO signature detected via accelerometer (g, where g represents the gravitational acceleration of 9.8 m/s2) prior to and during EILO

  4. Treadmill testing

    Time frame: Baseline and Perioprocedural

    Breathing frequency (breaths per minute)

  5. Treadmill testing

    Time frame: Base-line

    Tidal volume (Liters)

  6. Treadmill testing

    Time frame: Breath-by-breath baseline and Perioprocedural

    Ventilation (Liters/minute)

  7. Treadmill testing

    Time frame: Baseline and Periprocedural

    Partial pressure of arterial carbon dioxide estimated from end-tidal partial pressure of carbon dioxide; PetCO2) (mmHg)

  8. MRI Upper Airway Size

    Time frame: Baseline

    Length (mm), width (mm), and cross-sectional area (mm2) of oropharynx, supraglottis, glottis, immediate subglottis.

  9. Upper Airway Aerodynamics

    Time frame: Baseline and Periprocedural

    pressure (Pa) across oropharynx, supraglottis, and subglottis

  10. Upper Airway Aerodynamics

    Time frame: Baseline and Periprocedural

    volume flow rate (l/s) across oropharynx, supraglottis, and subglottis

  11. Upper Airway Aerodynamics

    Time frame: Baseline and Periprocedural

    flow velocities (m/s) across oropharynx, supraglottis, and subglottis

Secondary outcomes

  1. Self-rating of dyspnea

    Time frame: Baseline

    Dyspnea self-rating of breathing intensity and breathing unpleasantness rating on Visual Analog Scale of 0 to 100mm

Study contacts

Contact information is provided by the study sponsor or research team.

Rita R Patel

CONTACT

[email protected]

812-855-3886

Sponsors and collaborators

Lead sponsor

Indiana University

Other

Collaborators

  • National Institute on Deafness and Other Communication Disorders (NIDCD)
  • National Jewish Health
  • Purdue University

Registry information

Acronym: EILO

Important dates

Study start
2026
Primary completion
2032
Study completion
2032
First posted
Feb 19, 2026
Registry last updated
Mar 2, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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