Early Detection of Acute Respiratory Failure Using an Intelligent Respiratory Monitoring System
NCT ID: NCT07164586
Last Updated: 2025-09-10
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
ACTIVE_NOT_RECRUITING
300 participants
OBSERVATIONAL
2025-08-18
2025-12-22
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
Related Clinical Trials
Explore similar clinical trials based on study characteristics and research focus.
Home-based Pulmonary Rehabilitation in Patients With Chronic Obstructive Pulmonary Disease
NCT04722224
Chronic Obstructive Pulmonary Disease (COPD) Monitoring
NCT04671888
Auto-evaluation of Dyspnea
NCT03598569
The Effect of Use of Breathing Exercise Device and Reading Aloud on Vital Signs
NCT04978831
Wireless Assessment of Respiratory and Circulatory Distress in Chronic Obstructive Pulmonary Disease
NCT03467815
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
This is a prospective cohort study to be conducted in the emergency departments of Hospital Otávio de Freitas and Urgent Care Units (UPAs), involving volunteers of both sexes, aged 18 years or older, breathing spontaneously, and under suspicion of acute respiratory failure. Daily screening will be performed, collecting sociodemographic, blood gas, laboratory, and additional clinical data. When indicated, pulmonary function tests, respiratory muscle strength assessments, and diaphragmatic ultrasonography will be performed. Respiratory patterns will be recorded using the Respiratory Diagnostic Assistant (RDA), with data collected directly at the patient's bedside, preferably in a seated position or, if not feasible, in the supine position with the head of the bed elevated to 30°. The device will be used with appropriate protective filters and a face mask properly fitted to the patient, preceded by a clinical evaluation that includes peripheral oxygen saturation, respiratory rate, and signs of respiratory distress. The protocol comprises three minutes of spontaneous basal breathing to record time, volume, and flow variables.
Simultaneously with the RDA assessment, respiratory parameters will also be measured using conventional methods-manual or multiparameter monitor respiratory rate, arterial blood gas analysis (when clinically indicated), pulse oximetry, and spirometry-serving as reference standards for diagnostic accuracy analysis. The collected data will be analyzed using correlation coefficients, agreement tests, and ROC curves to assess the sensitivity, specificity, and overall performance of the RDA algorithm. In addition to accuracy, clinical usability of the device will be evaluated using the System Usability Scale (SUS) questionnaire, assessing interface clarity, ease of mask fitting, examination duration, data interpretation, and clinical applicability. The mean SUS score will be used as an indicator of acceptance, with values ≥68 considered satisfactory.
All clinical and technical data will be securely stored on an encrypted server with access restricted to the research team, in compliance with the Declaration of Helsinki, Brazilian regulations, and the General Data Protection Law (LGPD). Participation will be voluntary, requiring the signing of an informed consent form (ICF) by patients or, when applicable, their legal representatives. Data will be stored in Microsoft Excel 2016 (Microsoft®, USA) and analyzed using SPSS Statistics v.22.0. Descriptive variables will be presented as means and standard deviations or as medians and interquartile ranges, depending on their distribution, assessed using the Kolmogorov-Smirnov test.
The analysis will be guided by three main hypotheses: (1) Accuracy - to assess whether the intelligent monitoring system provides superior performance compared to conventional methods in detecting respiratory pattern alterations, using performance metrics such as accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the ROC curve (AUC), with comparisons made using McNemar's test for paired binary data and AUC comparisons using the z-test; (2) Validation - to verify the system's precision and reliability using the Intraclass Correlation Coefficient (ICC) and Bland-Altman analysis, as well as Cohen's Kappa index for categorical variables, with ICC values above 0.75 indicating satisfactory validation; (3) Usability - to assess system acceptance based on SUS scores, complemented by analysis of average training time and operational error rates, using the Student's t-test or Mann-Whitney test depending on data distribution.
The study is expected to generate robust quantitative data on the respiratory patterns of patients with suspected acute respiratory failure, contributing to the refinement of the device, the development of more accurate AI algorithms, and its safe and effective integration into clinical practice.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
COHORT
PROSPECTIVE
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Control Group - Healthy Individuals
Individuals without pulmonary impairment as confirmed through comprehensive respiratory assessment including pulmonary function testing (spirometry), respiratory muscle strength evaluation (manometry), and thorough medical history screening for previous respiratory or cardiopulmonary diseases. Participants must demonstrate normal lung function parameters, adequate respiratory muscle strength, and absence of any history of chronic obstructive pulmonary disease, asthma, pneumonia, tuberculosis, or other conditions that could compromise respiratory function
Respiratory Pattern Monitoring
Respiratory pattern assessment and continuous monitoring will be conducted utilizing the Respiratory Diagnostic Assistant, a device capable of providing comprehensive quantitative evaluation of respiratory variables including frequency, volume, flow rates, inspiratory/expiratory timing parameters, and respiratory entropy analysis, as well as qualitative analysis of respiratory pattern curves for volume and flow dynamics, incorporating entropy measurements for assessment of respiratory pattern complexity and variability.
Diaphragmatic Excursion
Diaphragmatic mobility assessment will be conducted using diaphragmatic ultrasonography, a method capable of providing comprehensive quantitative evaluation of diaphragmatic excursion parameters including range of motion, contraction velocity, muscle thickening during inspiration and expiration, as well as qualitative analysis of diaphragm muscle morphology and echogenicity, incorporating craniocaudal displacement measurements for assessment of contractile function and early detection of diaphragmatic dysfunction."
Respiratory Muscle Strength
Respiratory muscle strength assessment will be conducted using manovacuometry, a method capable of providing comprehensive quantitative evaluation of respiratory muscle force parameters including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), as well as qualitative analysis of contractile capacity and muscle endurance, incorporating peak pressure measurements and performance indices for assessment of global respiratory muscle function and early detection of muscle weakness
Pulmonary Function Assessment
Pulmonary function assessment will be conducted using spirometry, a method capable of providing comprehensive quantitative evaluation of respiratory function parameters including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio, and forced expiratory flow 25-75% (FEF25-75%), as well as qualitative analysis of flow-volume and volume-time curves, incorporating lung capacity and volume measurements for assessment of respiratory mechanics and early detection of obstructive and restrictive ventilatory disorders."
Data Acquisition System
The PowerLab C is a biomedical data acquisition system used as an auxiliary tool for physiological monitoring. In this study, it will be employed to collect respiratory signals and diaphragmatic excursion data through specific sensors, integrated with LabChart software for data visualization and analysis. The device is not considered an investigational intervention, but a supporting tool for data collection.
Borg Scale
The Borg Scale is a standardized self-report instrument used to assess perceived exertion and breathlessness during physical activity. In this study, it will be applied to evaluate participants' perception of respiratory effort. The scale is used solely for data collection and is not considered a therapeutic intervention.
Patient Identification Questionnaire
The Patient Identification Questionnaire is a standardized form used to collect sociodemographic and basic clinical information from participants, such as age, sex, and medical history. In this study, it will serve solely for data collection and will not constitute a therapeutic intervention.
Peak Expiratory Flow (PEF) Measurement
Peak Expiratory Flow (PEF) measurement is a rapid and noninvasive method to assess the maximum expiratory volume a participant can achieve after a full inhalation. In this study, participants will be seated upright and use a mouthpiece connected to a peak flow meter. After a deep inspiration, they will exhale forcefully, and three measurements will be taken with at least one minute between attempts; the highest value will be recorded. PEF values provide an objective measure of airflow limitation, correlate with asthma symptoms, and will be used solely for data collection, not as a therapeutic intervention
Intervention Group - Patients at Risk of Acute Respiratory Failure
This group will consist of adult patients (≥18 years), of both sexes, seen in emergency departments, urgent care units, or walk-in clinics associated with the study, who are in spontaneous breathing, with or without supplemental oxygen, and present with respiratory complaints associated with the risk of acute respiratory failure. Participants will be assessed using a sociodemographic and clinical form, including their documented medical diagnosis. Respiratory pattern monitoring will be conducted using the Respiratory Diagnostic Assistant (RDA) device, diaphragmatic mobility will be evaluated via ultrasonography, and muscle electrical activity will be assessed through surface electromyography. When clinically appropriate, pulmonary function tests and respiratory muscle strength assessments will also be performed, in accordance with the recommendations of the American Thoracic Society and the European Respiratory Society.
Respiratory Pattern Monitoring
Respiratory pattern assessment and continuous monitoring will be conducted utilizing the Respiratory Diagnostic Assistant, a device capable of providing comprehensive quantitative evaluation of respiratory variables including frequency, volume, flow rates, inspiratory/expiratory timing parameters, and respiratory entropy analysis, as well as qualitative analysis of respiratory pattern curves for volume and flow dynamics, incorporating entropy measurements for assessment of respiratory pattern complexity and variability.
Diaphragmatic Excursion
Diaphragmatic mobility assessment will be conducted using diaphragmatic ultrasonography, a method capable of providing comprehensive quantitative evaluation of diaphragmatic excursion parameters including range of motion, contraction velocity, muscle thickening during inspiration and expiration, as well as qualitative analysis of diaphragm muscle morphology and echogenicity, incorporating craniocaudal displacement measurements for assessment of contractile function and early detection of diaphragmatic dysfunction."
Respiratory muscle electrical activity
espiratory muscle electrical activity assessment will be conducted using surface electromyography, a method capable of providing comprehensive quantitative evaluation of muscle activation parameters including electrical signal amplitude, firing frequency, muscle recruitment patterns during inspiration and expiration, as well as qualitative analysis of synchronization and coordination between respiratory muscles, incorporating Root Mean Square (RMS) measurements and spectral analysis for assessment of respiratory neuromuscular function and detection of muscle fatigue.
Respiratory Muscle Strength
Respiratory muscle strength assessment will be conducted using manovacuometry, a method capable of providing comprehensive quantitative evaluation of respiratory muscle force parameters including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), as well as qualitative analysis of contractile capacity and muscle endurance, incorporating peak pressure measurements and performance indices for assessment of global respiratory muscle function and early detection of muscle weakness
Pulmonary Function Assessment
Pulmonary function assessment will be conducted using spirometry, a method capable of providing comprehensive quantitative evaluation of respiratory function parameters including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio, and forced expiratory flow 25-75% (FEF25-75%), as well as qualitative analysis of flow-volume and volume-time curves, incorporating lung capacity and volume measurements for assessment of respiratory mechanics and early detection of obstructive and restrictive ventilatory disorders."
Data Acquisition System
The PowerLab C is a biomedical data acquisition system used as an auxiliary tool for physiological monitoring. In this study, it will be employed to collect respiratory signals and diaphragmatic excursion data through specific sensors, integrated with LabChart software for data visualization and analysis. The device is not considered an investigational intervention, but a supporting tool for data collection.
Nijmegen Questionnaire
The Nijmegen Questionnaire is a standardized self-report instrument designed to assess symptoms related to dysfunctional breathing and hyperventilation. In this study, it will be administered to evaluate respiratory symptoms and their impact on participants' daily life. The questionnaire is used solely for data collection and is not considered a therapeutic intervention.
System Usability Scale (SUS)
The System Usability Scale (SUS) is a standardized questionnaire used to evaluate the usability and user experience of systems and devices. In this study, it will be applied to assess participants' perceptions of the usability of an intelligent respiratory monitoring system. The SUS will be used solely as a data collection tool and does not constitute a therapeutic intervention.
Borg Scale
The Borg Scale is a standardized self-report instrument used to assess perceived exertion and breathlessness during physical activity. In this study, it will be applied to evaluate participants' perception of respiratory effort. The scale is used solely for data collection and is not considered a therapeutic intervention.
Patient Identification Questionnaire
The Patient Identification Questionnaire is a standardized form used to collect sociodemographic and basic clinical information from participants, such as age, sex, and medical history. In this study, it will serve solely for data collection and will not constitute a therapeutic intervention.
Peak Expiratory Flow (PEF) Measurement
Peak Expiratory Flow (PEF) measurement is a rapid and noninvasive method to assess the maximum expiratory volume a participant can achieve after a full inhalation. In this study, participants will be seated upright and use a mouthpiece connected to a peak flow meter. After a deep inspiration, they will exhale forcefully, and three measurements will be taken with at least one minute between attempts; the highest value will be recorded. PEF values provide an objective measure of airflow limitation, correlate with asthma symptoms, and will be used solely for data collection, not as a therapeutic intervention
Interventions
Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.
Respiratory Pattern Monitoring
Respiratory pattern assessment and continuous monitoring will be conducted utilizing the Respiratory Diagnostic Assistant, a device capable of providing comprehensive quantitative evaluation of respiratory variables including frequency, volume, flow rates, inspiratory/expiratory timing parameters, and respiratory entropy analysis, as well as qualitative analysis of respiratory pattern curves for volume and flow dynamics, incorporating entropy measurements for assessment of respiratory pattern complexity and variability.
Diaphragmatic Excursion
Diaphragmatic mobility assessment will be conducted using diaphragmatic ultrasonography, a method capable of providing comprehensive quantitative evaluation of diaphragmatic excursion parameters including range of motion, contraction velocity, muscle thickening during inspiration and expiration, as well as qualitative analysis of diaphragm muscle morphology and echogenicity, incorporating craniocaudal displacement measurements for assessment of contractile function and early detection of diaphragmatic dysfunction."
Respiratory muscle electrical activity
espiratory muscle electrical activity assessment will be conducted using surface electromyography, a method capable of providing comprehensive quantitative evaluation of muscle activation parameters including electrical signal amplitude, firing frequency, muscle recruitment patterns during inspiration and expiration, as well as qualitative analysis of synchronization and coordination between respiratory muscles, incorporating Root Mean Square (RMS) measurements and spectral analysis for assessment of respiratory neuromuscular function and detection of muscle fatigue.
Respiratory Muscle Strength
Respiratory muscle strength assessment will be conducted using manovacuometry, a method capable of providing comprehensive quantitative evaluation of respiratory muscle force parameters including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), as well as qualitative analysis of contractile capacity and muscle endurance, incorporating peak pressure measurements and performance indices for assessment of global respiratory muscle function and early detection of muscle weakness
Pulmonary Function Assessment
Pulmonary function assessment will be conducted using spirometry, a method capable of providing comprehensive quantitative evaluation of respiratory function parameters including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio, and forced expiratory flow 25-75% (FEF25-75%), as well as qualitative analysis of flow-volume and volume-time curves, incorporating lung capacity and volume measurements for assessment of respiratory mechanics and early detection of obstructive and restrictive ventilatory disorders."
Data Acquisition System
The PowerLab C is a biomedical data acquisition system used as an auxiliary tool for physiological monitoring. In this study, it will be employed to collect respiratory signals and diaphragmatic excursion data through specific sensors, integrated with LabChart software for data visualization and analysis. The device is not considered an investigational intervention, but a supporting tool for data collection.
Nijmegen Questionnaire
The Nijmegen Questionnaire is a standardized self-report instrument designed to assess symptoms related to dysfunctional breathing and hyperventilation. In this study, it will be administered to evaluate respiratory symptoms and their impact on participants' daily life. The questionnaire is used solely for data collection and is not considered a therapeutic intervention.
System Usability Scale (SUS)
The System Usability Scale (SUS) is a standardized questionnaire used to evaluate the usability and user experience of systems and devices. In this study, it will be applied to assess participants' perceptions of the usability of an intelligent respiratory monitoring system. The SUS will be used solely as a data collection tool and does not constitute a therapeutic intervention.
Borg Scale
The Borg Scale is a standardized self-report instrument used to assess perceived exertion and breathlessness during physical activity. In this study, it will be applied to evaluate participants' perception of respiratory effort. The scale is used solely for data collection and is not considered a therapeutic intervention.
Patient Identification Questionnaire
The Patient Identification Questionnaire is a standardized form used to collect sociodemographic and basic clinical information from participants, such as age, sex, and medical history. In this study, it will serve solely for data collection and will not constitute a therapeutic intervention.
Peak Expiratory Flow (PEF) Measurement
Peak Expiratory Flow (PEF) measurement is a rapid and noninvasive method to assess the maximum expiratory volume a participant can achieve after a full inhalation. In this study, participants will be seated upright and use a mouthpiece connected to a peak flow meter. After a deep inspiration, they will exhale forcefully, and three measurements will be taken with at least one minute between attempts; the highest value will be recorded. PEF values provide an objective measure of airflow limitation, correlate with asthma symptoms, and will be used solely for data collection, not as a therapeutic intervention
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Inclusion Criteria
* Age greater than or equal to 18 years
* Spontaneous breathing
* Patients awaiting care in emergency departments, urgent care units, and emergency services
* Presence of complaints associated with respiratory difficulty
* Patients at risk of acute respiratory failure
* With or without supplemental oxygen therapy
* Ability to remain without oxygen therapy for a minimum period of three minutes
Exclusion Criteria
* Anxiety validated through qualitative assessment
* Poor mask fit and/or presence of air leaks
* Facial fracture or trauma
* Refusal to participate in the study or sign the informed consent form
* Contraindications to performing manovacuometry and spirometry, when appropriate, according to the recommendations of the American Thoracic Society and European Respiratory Society (Graham et al., 2019)
18 Years
90 Years
ALL
Yes
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
Fundação de Amparo à Ciência e Tecnologia de Pernambuco
OTHER
Conselho Nacional de Desenvolvimento Científico e Tecnológico
OTHER_GOV
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.
OTHER_GOV
University of Pernambuco
OTHER
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Shirley Lima Campos
PhD
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
Emergency Care Unit from Engenho Velho
Jaboatão dos Guararapes, Pernambuco, Brazil
Department of Physical Therapy
Recife, Pernambuco, Brazil
Otávio de Freitas Hospital
Recife, Pernambuco, Brazil
Countries
Review the countries where the study has at least one active or historical site.
Related Links
Access external resources that provide additional context or updates about the study.
Development and validation of a respiratory pattern analysis system for Post-COVID-19 patients
Diagnosis and Epidemiology of Acute Respiratory Failure
Biomarker-Based Classification of Patients With Acute Respiratory Failure Into Inflammatory Subphenotypes: A Single-Center Exploratory Study
Sonographic evaluation of the diaphragm in critically ill patients. Technique and clinical applications
Leveraging intrinsic non-sinusoidal patterns to infer search behavior to predict exposure to respiratory stressors
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
7.741.786
Identifier Type: -
Identifier Source: org_study_id
More Related Trials
Additional clinical trials that may be relevant based on similarity analysis.