Impact of 3D-EIT-Guided Acapella Breathing Training on Lung Ventilation Distribution

NCT07733843 | Not Yet Recruiting

• 1 other identifier: B2026-441
• Study Type: interventional
• Target: 30
• Locations: 0 countries
• Sites: N/A

Brief Summary

The goal of this randomized clinical trial is to determine whether real-time visual feedback from three-dimensional electrical impedance tomography (3D-EIT) can improve the effects of Acapella breathing exercises in adults recovering from critical illness. 3D-EIT is a noninvasive bedside imaging method that provides real-time information about how ventilation is distributed within the lungs. Participants will be randomly assigned to one of two groups. Both groups will perform a standardized Acapella breathing exercise while 3D-EIT data and vital signs are recorded. Participants in the control group will receive routine verbal and demonstration-based breathing instructions without viewing the EIT images. Participants in the intervention group will receive the same instructions and will also view their own real-time 3D-EIT ventilation images. They will use this visual feedback to adjust their breathing with the goal of increasing ventilation in the dorsal regions of the lungs and/or achieving a more even distribution of ventilation. The main question is whether 3D-EIT-guided visual feedback results in a greater improvement in end-expiratory lung impedance (EELI) after breathing exercise compared with routine instruction alone. The study will also examine changes in regional ventilation distribution, ventilation inhomogeneity, vital signs, breathing discomfort, comfort and tolerance, achievement of the breathing-training target, and adverse events. Approximately 30 participants will be enrolled and randomly assigned in a 1:1 ratio to the two study groups.

Conditions

Critical Illness Recovery; Pulmonary Rehabilitation

Outcome Measures

Primary Outcomes (1)

• Change From Baseline in End-Expiratory Lung Impedance (ΔEELI)

  Change in end-expiratory lung impedance (ΔEELI) will be measured using three-dimensional electrical impedance tomography (3D-EIT). ΔEELI is defined as the EELI measured during the stable breathing period after the intervention minus the EELI measured during the stable breathing period before the intervention.

  From baseline before the intervention to 10 minutes after completion of the single Acapella training session

Secondary Outcomes (2)

• Change From Baseline in Dorsal Lung Ventilation Proportion

  Baseline and after a 10-minute recovery period following the single Acapella training session

• Change From Baseline in Global Inhomogeneity Index

  Baseline and after a 10-minute recovery period following the single Acapella training session

Study Arms (2)

3D-EIT Visual Biofeedback Group

EXPERIMENTAL

Participants will perform standardized Acapella breathing exercises with real-time 3D-EIT visual biofeedback in addition to routine verbal and demonstration-based instructions. Participants will view their own ventilation images and adjust their breathing to increase dorsal ventilation and/or improve ventilation homogeneity.

Device: Acapella Oscillating Positive Expiratory Pressure Breathing Exercise; Device: Real-Time 3D Electrical Impedance Tomography Visual Biofeedback

Conventional Acapella Training Group

ACTIVE COMPARATOR

Participants will perform standardized Acapella breathing exercises under routine verbal and demonstration-based instructions without access to real-time 3D-EIT visual feedback. 3D-EIT data will still be recorded for outcome assessment.

Device: Acapella Oscillating Positive Expiratory Pressure Breathing Exercise

Interventions

Acapella Oscillating Positive Expiratory Pressure Breathing Exercise DEVICE

Participants will perform standardized breathing exercises using an Acapella oscillating positive expiratory pressure device. Each session will consist of 3 sets of 8-10 breaths, with 10-15 seconds of rest between breaths and 1-2 minutes of rest between sets. Participants will be instructed to inhale slowly and exhale through the Acapella device. The resistance setting will be predetermined and kept unchanged throughout the session.

3D-EIT Visual Biofeedback Group; Conventional Acapella Training Group

Real-Time 3D Electrical Impedance Tomography Visual Biofeedback DEVICE

Participants in the experimental group will view their own real-time 3D electrical impedance tomography (3D-EIT) ventilation images while performing standardized Acapella breathing exercises. The visual feedback will be used to guide breathing adjustments with the aim of increasing dorsal lung ventilation and/or improving ventilation homogeneity. The 3D-EIT system will also record ventilation data for outcome assessment.

3D-EIT Visual Biofeedback Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥18 years.
• Adult patients in the stable recovery phase following critical illness, breathing spontaneously, alert, and able to follow instructions (suggested Richmond Agitation-Sedation Scale \[RASS\] score of -1 to +1).
• Hemodynamically stable, with no vasopressor support or only a low and stable dose of vasopressors.
• Receiving stable low-flow oxygen therapy or equivalent non-escalating respiratory support, without an anticipated need for escalation in the short term.
• Clinically considered suitable for standardized Acapella breathing exercises.
• Able and willing to provide written informed consent.

You may not qualify if:

• Significant hemodynamic instability or clinically significant cardiac arrhythmia.
• Untreated pneumothorax or active hemoptysis.
• Severe chest wall skin injury or allergy to electrode materials that prevents application of the electrical impedance tomography electrodes.
• Significant delirium or inability to understand or follow study instructions.
• Any other condition that, in the investigator's judgment, makes the participant unsuitable for participation in the study.

Sponsors & Collaborators

• Shanghai Zhongshan Hospital: lead

Central Study Contacts

Yuxian Wang

CONTACT

+86 021 6404 1990; wang.yuxian@zs-hospital.sh.cn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 25, 2026
• First Posted: July 29, 2026
• Study Start: July 31, 2026
• Primary Completion: August 1, 2026
• Study Completion (Estimated): March 21, 2027
• Last Updated: July 29, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share