Imaging Brain Fluids During Breathing

July 24, 2026 updated by: Boston University Charles River Campus

Neuroimaging the Impact of Respiration and Respiratory-gated Neuromodulation on Human Glymphatic Physiology

This study will perform magnetic resonance imaging (MRI) measurements of hemodynamics and cerebrospinal fluid flow across breathing tasks and during breath-locked neuromodulation.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Cerebrospinal fluid (CSF) flow is essential for brain health, as it clears waste products from the brain. This study will investigate how breathing affects the flow of CSF around the brain. The investigators will perform high resolution magnetic resonance imaging (MRI) scans in participants who are breathing in specific patterns or performing simple tasks and test the effects on CSF flow. Participants will complete an imaging study visit in which the investigators will image their brain activity while they perform simple tasks, including paced breathing tasks. The participants will be split into two arms: (1) paced breathing (25 participants low resolution, 15 participants high resolution), (2) transcutaneous vagal nerve stimulation (25 participants low resolution, 15 participants high resolution). The MRI scans will take place in the 7 Tesla MRI scanner at Massachusetts General Hospital.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
81

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Jessica Yee, BS
  • Phone Number: 7742852038
  • Email: jessyee@bu.edu

Study Contact Backup

  • Name: Courtney Zambello, BA
  • Phone Number: 7812019815
  • Email: cgz@bu.edu

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital
      • Boston, Massachusetts, United States, 02215
        • Boston University - Charles River Campus

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adult age 18-70 years

Exclusion Criteria:

  • No ferrous metal implanted in head or body
  • No history of major head trauma
  • No neurological or psychiatric disorder
  • Not using medication that affects brain function
  • No implanted electronic devices (e.g. pacemaker)
  • No implant that poses an MR contraindication
  • Not pregnant, suspect they are pregnant, or seeking to become pregnant
  • Not claustrophobic
  • No piercings or jewelry that cannot be removed
  • Does not weigh more than 250 pounds
  • Normal or contact-corrected normal vision

Exclusion for transcutaneous vagus nerve stimulation (tVNS) arm:

  • Conditions of skin or anatomy that affect left auricle or forehead skin and could impact placement of electrodes for tVNS or forehead stimulation
  • Diagnosis of significant cardiovascular or cerebrovascular disease [e.g. congestive heart failure, stroke, cardiac conduction disorders (including: bundle branch block, heart block, long Q-T syndrome), history of asystole or non-sustained ventricular tachycardia.
  • Bradycardia (defined as resting heart rate <50 bpm)
  • Hypotension defined as blood pressure <90/60 mmHg

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Breath task
Participants will breathe in specific patterns.
Behavioral: Breathing task
Participants will be asked to breathe in specific patterns.
Experimental: Transcutaneous vagal nerve stimulation
Participants will receive transcutaneous vagal nerve stimulation in specific patterns.
Behavioral: Breathing task
Participants will be asked to breathe in specific patterns.
Device: Transcutaneous vagal nerve stimulation
Noninvasive stimulation vs sham stimulation will be delivered via an auricular device.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
functional magnetic resonance imaging (fMRI) signals
Time Frame: During study (2 hours)
fMRI measures of hemodynamic responses. Units: percent signal change
During study (2 hours)
Cerebrospinal fluid (CSF) signals
Time Frame: During study (2 hours)
MR-based measures of CSF signals. Units: percent signal change
During study (2 hours)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Heart rate
Time Frame: During study ( 2 hours)
Heart rate variability will be calculated. Units: milliseconds (ms)
During study ( 2 hours)
Pulse oximetry
Time Frame: During study ( 2 hours)
Amplitude of pulse oximetry signal. Units: arbitrary (no physical units are output by this system)
During study ( 2 hours)
Respiratory physiology timing
Time Frame: During study (2 hours)
Breath timing. Units: Hertz (Hz)
During study (2 hours)
Respiratory physiology amplitude
Time Frame: During study (2 hours)
Breath amplitude. Units: arbitrary (no physical units output by this sensor)
During study (2 hours)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Boston University Charles River Campus

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Center for Complementary and Integrative Health (NCCIH)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Laura Lewis, PhD, Boston University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 18, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 3, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 16, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 6, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 6029E
  • R01AT011429 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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