Recruiting

Observational Study

Sponsor:

Emory University

Code:

NCT05350332

Conditions

Obstructive Sleep Apnea

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Negative Pressure Ventilator

Pulmonary Function Testing (PFT)

Transcutaneous Phrenic Nerve Stimulation

Percutaneous Phrenic Nerve Stimulation

Study Details

Brief summary:

Obstructive sleep apnea (OSA) is a disorder where a person has recurrent choking episodes during sleep. Surgery can treat OSA and drug induced sleep endoscopy (DISE) is a procedure that surgeons use to evaluate the throat while a person is sedated, mimicking sleep, to help determine if surgery might be effective. Lung volume can influence OSA severity but the relationship between lung function and throat collapse seen on DISE has not been well studied. This study aims to see if lung volume influences what is happening in the throat during DISE. Participants will be recruited from the sleep surgery clinic where they are being evaluated for surgery to treat their OSA. Participants will have a DISE that is performed as part of their routine surgical workup for treatment of OSA. Additionally, during the DISE, they will participate in one of two study groups. One group will have a negative pressure "turtle shell" ventilator placed over the participants chest during DISE to manipulate lung volumes to see if it can improve throat collapse. A second group will have phrenic nerve stimulation to contract the diaphragm to improve lung volumes to see if it can improve throat collapse. Both groups will also have a lung function test performed. The findings of this study will be important in improving pre-surgical evaluation of patients to better predict if surgery can help as well as potentially develop new surgical therapies for the treatment of OSA.

Conditions

Obstructive Sleep Apnea

Study ID

NCT05350332

Start date

Jun 30, 2022

Status verified date

Aug, 2026

Completion date

Jun, 2027

Anticipated

Primary completion date

Jun, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Adult patients (≥ 18 yrs) willing and capable of providing informed consent
  • Obstructive sleep apnea (AHI ≥ 5 events/hour)
  • Must be willing and able to provide informed consent to participate in the study.
  • Interested in surgical treatments of OSA and have consented for a DISE procedure as part of their routine clinical evaluation.

  • Patients are evaluated and cleared by anesthesia prior to the procedure.

Exclusion Criteria:

  • No significant uncontrolled medical co-morbidities (e.g., uncontrolled hypertension, unstable angina, uncompensated heart failure or COPD).
  • Any medical comorbidity that would prevent the patient from receiving anesthesia or having surgery
  • Inability to tolerate negative pressure ventilator or perform PFT (i.e. claustrophobia)
  • No incapacitating disability that interferes with execution of the protocol

Study Design

Enrollment

151 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Negative Pressure Ventilator

Participants with obstructive sleep apnea (OSA) who are being evaluated for surgical treatment of their OSA and having a routine clinical DISE will have their lung volume increased with a non-invasive negative pressure ventilator. Participants will also have a pulmonary function test performed per routine clinical protocol, but for research purposes only (i.e., not part of usual care).

experimental: Phrenic Nerve Stimulation

Participants with obstructive sleep apnea (OSA) who are being evaluated for surgical treatment of their OSA and having a routine clinical DISE will have their lung volume increased with transcutaneous or percutaneous phrenic nerve stimulation. Participants will also have a pulmonary function test performed per routine clinical protocol, but for research purposes only (i.e., not part of usual care).

Interventions

Negative Pressure Ventilator

The negative pressure ventilator is an off-the-shelf FDA-approved device designed to treat respiratory patients with hypoventilation syndromes. This ventilator places the torso within a fixed container that is connected to a vacuum source, which inflates the lungs by pulling a negative pressure around the chest and abdomen. After the clinically routine DISE, a negative pressure ventilator will be placed on the participant's chest to increase lung volumes and the DISE evaluation will be repeated to observe changes.

Pulmonary Function Testing (PFT)

PFT is a routine standardized clinical test evaluating lung function, consisting of two parts: spirometry and body plethysmography. In spirometry, participants breathe through a mouthpiece that measures airflow and volume to determine normal and maximal volume of inspiration/expiration. Body plethysmography is performed to calculate residual lung volumes. Participants enter in an enclosed chamber where they breathe through a mouthpiece. Changes in pressure in the sealed chamber during breathing are used to calculate the volume of air that remains in the lung after expiration. A MiniBox+ device may be used. The MiniBox+ device derives total lung capacity (TLC) during tidal breathing by the analysis of gas pressures and airflows immediately preceding and immediately following airway occlusions to calculate the same measures as conventional PFT analysis.

Transcutaneous Phrenic Nerve Stimulation

Phrenic nerve stimulation (PNS) will be performed transcutaneously using a commercially available and FDA approved peripheral neurostimulator. (Digitimer DS8R Bipolar Constant Current Stimulator). The neurostimulator consists of a stimulation generating box connected to electrodes that will be placed over the skin of the neck bilaterally over both phrenic nerves where an bipolar electric current will be used to stimulate the phrenic nerve leading to diaphragm contraction.

Percutaneous Phrenic Nerve Stimulation

Under ultrasound guidance, a stimulating catheter (Stimulong Sono II) will be inserted into the right side of the neck and positioned adjacent to the phrenic nerve as it travels along the anterior scalene muscle. The catheter will be connected to a commercially available research neurostimulator. Unilateral phrenic nerve stimulation will be performed for no more than 30 minutes.

Primary outcome measure

  • Expiratory Reserve Volume (ERV) [ Time Frame: During PFT ]
  • Functional Residual Capacity (FRC) [ Time Frame: During PFT ]
  • Change in VOTE Collapse Patterns - Degree of Obstruction [ Time Frame: During clinical DISE and intervention DISE ]
  • Change in VOTE Collapse Patterns - Configuration of Obstruction [ Time Frame: During clinical DISE and intervention DISE ]
  • Change in Critical Closing Pressure (Pcrit) [ Time Frame: During clinical DISE and intervention DISE ]
  • Change in Pharyngeal Opening Pressures [ Time Frame: During clinical DISE and intervention DISE ]

Central Contacts and Locations

Central contacts

Jason Yu, MD

470-763-3887jyu40@emory.edu

Locations

Emory University Hospital Midtown

Recruiting

Atlanta, Georgia, United States, 30308

More Information

Sponsor

Emory University

Last update posted

Aug 26, 2026

Last verified

Aug, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Emory University on 2026-08-26.