Pulmonary PerfusionNELSBNCT07489950
Non-apnea Electrical Impedance Tomography for Bedside Ventilation-Perfusion Assessment: a Prospective Cross-over Validation Study
A study testing Saline-contrast EIT with a non-apnea algorithm in people with Pulmonary Perfusion and Ventilation-Perfusion Ratio, run by Ruijin Hospital at 1 site in China.
Trial summary
Title: Validating the Accuracy of Lung Blood Flow Monitoring Without Breath-Holding Under Spontaneous Breathing Support Purpose: The purpose of this study is to evaluate the accuracy of a new Electrical Impedance Tomography (EIT) technique that measures lung blood flow (perfusion) without requiring patients to hold… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Pulmonary Perfusion, Ventilation-Perfusion Ratio, Respiratory Insufficiency
- What is being tested?
- Saline-contrast EIT with a non-apnea algorithm
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteChina
- Study dates
- 19 Mar 2026to 13 Apr 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Patients aged ≥ 18 years.
- Requiring respiratory support including Nasal Cannula, High-Flow Nasal Oxygen (HFNO), or Pressure Support Ventilation (PSV).
- Hemodynamically stable.
- Able to tolerate a brief respiratory pause (for the reference group).
- Signed informed consent.
Who cannot join
- Pregnancy or breastfeeding.
- Contraindications to electrical impedance tomography (e.g., cardiac pacemaker, skin integrity issues on the chest).
- Severe circulatory failure or cardiogenic shock.
- Known allergy to hypertonic saline.
Trial locations and contacts
1 site in 1 country.
China1 site
Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine
Shanghai, Shanghai Municipality, 200025
About this study
Official title: Non-apnea Saline-contrast EIT for Lung Perfusion Imaging in Spontaneously Breathing Patients: A Prospective Cross-over Study
Title: Validating the Accuracy of Lung Blood Flow Monitoring Without Breath-Holding Under Spontaneous Breathing Support
Purpose: The purpose of this study is to evaluate the accuracy of a new Electrical Impedance Tomography (EIT) technique that measures lung blood flow (perfusion) without requiring patients to hold their breath. We aim to determine if this "non-apnea" method provides results consistent with the current clinical gold standard (the "pause" method).
Read more
Background: EIT is a non-invasive bedside tool used to monitor lung function. The traditional method for measuring lung blood flow requires patients to hold their breath for 5-8 seconds during a saline injection to avoid interference from breathing. However, many patients-especially those using a nasal cannula, high-flow nasal oxygen (HFNO), or pressure support ventilation (PSV)-must maintain continuous spontaneous breathing and find it difficult or unsafe to hold their breath. If a "non-apnea" method is proven accurate, it will make monitoring safer and easier for these patients.
What the Study Involves: The study includes stable adult patients who are breathing spontaneously. Each patient undergoes two measurements in a randomized order:
Standard Reference (Pause Method): Measurement taken during a brief, guided breath-hold.
Test Method (Non-Apnea Method): Measurement taken during normal, uninterrupted breathing while receiving respiratory support (Nasal Cannula, HFNO, or PSV).
Expected Significance: By comparing the lung images and ventilation/perfusion (V/Q) data from both methods, this study seeks to validate the reliability and precision of the non-apnea approach. This would allow clinicians to assess lung health in spontaneously breathing patients without interrupting their natural breathing rhythm.
Read the detailed description
Study Design
This is a prospective, randomized, cross-over, within-subject validation study of accuracy.
The primary objective is to quantitatively assess the agreement between lung perfusion data acquired during uninterrupted spontaneous breathing (non-apnea method) and data acquired during the standard end-expiratory pause (pause method).
Participant Population and Respiratory Support
The study enrolls stable adult patients with active spontaneous breathing efforts.
Participants are categorized by the level of respiratory support they receive: Conventional Oxygen Therapy (Nasal Cannula), High-Flow Nasal Oxygen (HFNO), or Pressure Support Ventilation (PSV).
Conventional Oxygen Therapy includes patients using a nasal cannula or simple mask without pressure support.
HFNO and PSV groups include patients receiving constant high-flow oxygen or patient-triggered mechanical ventilation.
Procedures and Interventions
Each participant receives two 10 mL boluses of 10% NaCl (hypertonic saline) via a central venous catheter.
A 10-minute washout period is maintained between injections.
In the Pause Method, injection occurs during a 5-8 second end-expiratory hold (coached for nasal cannula/HFNO; ventilator-controlled for PSV).
In the Non-Apnea Method, injection occurs during continuous, ongoing breathing without any breathing commands or ventilator setting changes.
Technical Approach to Ensure Accuracy
Specialized algorithms are used to extract saline-contrast signals from the "noise" of spontaneous tidal breaths.
Advanced frequency filtering is applied to separate ventilation-related and perfusion-related impedance changes.
In non-apnea mode, the software identifies the perfusion window using a pixel-triggered approach.
This method detects the impedance drop relative to the End-Expiratory Lung Impedance (EELI) baseline to maintain precision despite moving baselines.
Outcome Measures
The primary outcome is the pixel-wise correlation of perfusion maps between the two methods, assessed by the Spearman correlation coefficient (r).
Secondary outcomes include the agreement of V/Q match%, dead space%, and shunt% using Bland-Altman analysis.
The study also assesses whether the type of support (Nasal Cannula vs. HFNO vs. PSV) affects the accuracy of the non-apnea method.
Feasibility is documented by the success rate of analyzable acquisitions and categorized failure reasons.
- Conditions
- Pulmonary Perfusion, Ventilation-Perfusion Ratio, Respiratory Insufficiency, Critical Illness
- Being tested
- Saline-contrast EIT with a non-apnea algorithm
- Keywords
- Spontaneous Breathing, Lung Perfusion, Electrical Impedance Tomography, Ventilation-Perfusion Matching
- Medical subject headings
- Respiratory Insufficiency, Critical Illness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Saline-contrast EIT with a non-apnea algorithmDiagnostic test
Also called EIT Lung Perfusion Imaging
Participants receive a central venous bolus injection of 10 mL 10% NaCl. Lung perfusion is then assessed using Electrical Impedance Tomography (EIT). The intervention evaluates two acquisition conditions: one during a brief respiratory pause (reference) and one during uninterrupted spontaneous breathing (test).
| Study group | Role | What they receive |
|---|---|---|
| Standard Breath-hold Method | Active comparator | 1. This arm serves as the reference standard for EIT perfusion measurement.
2. A 10 mL bolus of 10% NaCl is injected during a 5-8 second end-expiratory pause.
3. For patients on Nasal Cannula or HFNO, the pause is achieved via coached respiratory instruction; for patients on PSV, the ventilator's end-expiratory hold function is used Receives: Diagnostic Test: Saline-contrast EIT with a non-apnea algorithm |
| Non-apnea Method | Experimental | 1. This arm evaluates the feasibility and accuracy of perfusion measurement during uninterrupted breathing.
2. A 10 mL bolus of 10% NaCl is injected while the patient maintains a natural, continuous breathing rhythm.
3. This method is tested across all included respiratory support modes, including Nasal Cannula, HFNO, and PSV, without any respiratory pause or instruction. Receives: Diagnostic Test: Saline-contrast EIT with a non-apnea algorithm |
What is being measured
The primary outcome is the main question the study is designed to answer.
Spearman correlation coefficient (r)
The Spearman correlation coefficient will be calculated to assess the voxel-by-voxel agreement of lung perfusion maps generated by the non-apnea algorithm compared to the reference standard (breath-hold method).
Measured: Within 30 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Mar 2026
- Study start19 Mar 2026
- Primary completion13 Apr 2026
- Study completion13 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pulmonary PerfusionStudies of the same condition, open and under way.
- More trials run by Ruijin HospitalThe sponsor's other registered studies.
- 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
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ruijin Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Hongping Qu, Study chair, Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07489950
- Sponsor's protocol ID
- 2026063
- Acronym
- NELSB
- Status last verified
- Jan 2026
- First submitted
- 18 Mar 2026
- Last updated
- 23 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Non-apnea Saline-contrast EIT for Lung Perfusion Imaging in Spontaneously Breathing Patients: A Prospective Cross-over Study
- ClinicalTrials.gov ID
- NCT07489950
- Acronym / sponsor ID
- NELSB / 2026063
- Conditions
- Pulmonary Perfusion, Ventilation-Perfusion Ratio, Respiratory Insufficiency, Critical Illness
- Keywords
- Spontaneous Breathing, Lung Perfusion, Electrical Impedance Tomography, Ventilation-Perfusion Matching
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Ruijin HospitalUniversity, hospital or other
- Study start
- 19 Mar 2026 (actual)
- Primary completion
- 13 Apr 2026 (actual)
- Study completion
- 13 Apr 2026 (actual)
- First posted
- 24 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Title: Validating the Accuracy of Lung Blood Flow Monitoring Without Breath-Holding Under Spontaneous Breathing Support
Purpose: The purpose of this study is to evaluate the accuracy of a new Electrical Impedance Tomography (EIT) technique that measures lung blood flow (perfusion) without requiring patients to hold their breath. We aim to determine if this "non-apnea" method provides results consistent with the current clinical gold standard (the "pause" method).
Background: EIT is a non-invasive bedside tool used to monitor lung function. The traditional method for measuring lung blood flow requires patients to hold their breath for 5-8 seconds during a saline injection to avoid interference from breathing. However, many patients-especially those using a nasal cannula, high-flow nasal oxygen (HFNO), or pressure support ventilation (PSV)-must maintain continuous spontaneous breathing and find it difficult or unsafe to hold their breath. If a "non-apnea" method is proven accurate, it will make monitoring safer and easier for these patients.
What the Study Involves: The study includes stable adult patients who are breathing spontaneously. Each patient undergoes two measurements in a randomized order:
Standard Reference (Pause Method): Measurement taken during a brief, guided breath-hold.
Test Method (Non-Apnea Method): Measurement taken during normal, uninterrupted breathing while receiving respiratory support (Nasal Cannula, HFNO, or PSV).
Expected Significance: By comparing the lung images and ventilation/perfusion (V/Q) data from both methods, this study seeks to validate the reliability and precision of the non-apnea approach. This would allow clinicians to assess lung health in spontaneously breathing patients without interrupting their natural breathing rhythm.
Detailed description
Study Design
This is a prospective, randomized, cross-over, within-subject validation study of accuracy.
The primary objective is to quantitatively assess the agreement between lung perfusion data acquired during uninterrupted spontaneous breathing (non-apnea method) and data acquired during the standard end-expiratory pause (pause method).
Participant Population and Respiratory Support
The study enrolls stable adult patients with active spontaneous breathing efforts.
Participants are categorized by the level of respiratory support they receive: Conventional Oxygen Therapy (Nasal Cannula), High-Flow Nasal Oxygen (HFNO), or Pressure Support Ventilation (PSV).
Conventional Oxygen Therapy includes patients using a nasal cannula or simple mask without pressure support.
HFNO and PSV groups include patients receiving constant high-flow oxygen or patient-triggered mechanical ventilation.
Procedures and Interventions
Each participant receives two 10 mL boluses of 10% NaCl (hypertonic saline) via a central venous catheter.
A 10-minute washout period is maintained between injections.
In the Pause Method, injection occurs during a 5-8 second end-expiratory hold (coached for nasal cannula/HFNO; ventilator-controlled for PSV).
In the Non-Apnea Method, injection occurs during continuous, ongoing breathing without any breathing commands or ventilator setting changes.
Technical Approach to Ensure Accuracy
Specialized algorithms are used to extract saline-contrast signals from the "noise" of spontaneous tidal breaths.
Advanced frequency filtering is applied to separate ventilation-related and perfusion-related impedance changes.
In non-apnea mode, the software identifies the perfusion window using a pixel-triggered approach.
This method detects the impedance drop relative to the End-Expiratory Lung Impedance (EELI) baseline to maintain precision despite moving baselines.
Outcome Measures
The primary outcome is the pixel-wise correlation of perfusion maps between the two methods, assessed by the Spearman correlation coefficient (r).
Secondary outcomes include the agreement of V/Q match%, dead space%, and shunt% using Bland-Altman analysis.
The study also assesses whether the type of support (Nasal Cannula vs. HFNO vs. PSV) affects the accuracy of the non-apnea method.
Feasibility is documented by the success rate of analyzable acquisitions and categorized failure reasons.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard Breath-hold Method | Active comparator | Diagnostic Test: Saline-contrast EIT with a non-apnea algorithm1. This arm serves as the reference standard for EIT perfusion measurement. 2. A 10 mL bolus of 10% NaCl is injected during a 5-8 second end-expiratory pause. 3. For patients on Nasal Cannula or HFNO, the pause is achieved via coached respiratory instruction; for patients on PSV, the ventilator's end-expiratory hold function is used |
| Non-apnea Method | Experimental | Diagnostic Test: Saline-contrast EIT with a non-apnea algorithm1. This arm evaluates the feasibility and accuracy of perfusion measurement during uninterrupted breathing. 2. A 10 mL bolus of 10% NaCl is injected while the patient maintains a natural, continuous breathing rhythm. 3. This method is tested across all included respiratory support modes, including Nasal Cannula, HFNO, and PSV, without any respiratory pause or instruction. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Patients aged ≥ 18 years.
- Requiring respiratory support including Nasal Cannula, High-Flow Nasal Oxygen (HFNO), or Pressure Support Ventilation (PSV).
- Hemodynamically stable.
- Able to tolerate a brief respiratory pause (for the reference group).
- Signed informed consent.
Key exclusion criteria (4 listed)
- Pregnancy or breastfeeding.
- Contraindications to electrical impedance tomography (e.g., cardiac pacemaker, skin integrity issues on the chest).
- Severe circulatory failure or cardiogenic shock.
- Known allergy to hypertonic saline.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Saline-contrast EIT with a non-apnea algorithmAlso: EIT Lung Perfusion ImagingParticipants receive a central venous bolus injection of 10 mL 10% NaCl. Lung perfusion is then assessed using Electrical Impedance Tomography (EIT). The intervention evaluates two acquisition conditions: one during a brief respiratory pause (reference) and one during uninterrupted spontaneous breathing (test). | Diagnostic test | Non-apnea Method, Standard Breath-hold Method |
Primary outcome
Spearman correlation coefficient (r)
Time frame: Within 30 minutes
The Spearman correlation coefficient will be calculated to assess the voxel-by-voxel agreement of lung perfusion maps generated by the non-apnea algorithm compared to the reference standard (breath-hold method).
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Apr 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Hongping Qu study chair
Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Saline-contrast EIT with a non-apnea algorithm in people with Pulmonary Perfusion and Ventilation-Perfusion Ratio, run by Ruijin Hospital at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Spearman correlation coefficient (r) (time frame: Within 30 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Apr 2026.