Evaluation of the Diagnostic Capacity of a Smart Mattress Versus Conventional Polysomnography
Evaluation of the Diagnostic Capacity of a Smart Mattress Versus Conventional Polysomnography
This project aims to develop and evaluate an innovative, non-invasive diagnostic system based on a smart mattress for detecting obstructive sleep apnea (OSA), as well as assessing overall sleep quality and identifying periodic limb movements. The main goal is to improve the accuracy of sleep apnea diagnosis while providing a less invasive solution suitable for home use, ultimately enhancing patients' quality of life.
A descriptive, observational, prospective study will be conducted to analyze data obtained from diagnostic polysomnographies performed at the Sleep Unit of San Pedro Hospital between November 17, 2026, and March 1, 2028. Patients will use the smart mattress, and its measurements will be compared with polysomnography results. This comparison will allow for the optimization of the mattress's artificial intelligence, training it to accurately recognize respiratory patterns and sleep-related events, including positional apneas and periodic limb movements.
Key technical objectives include:
Determining the sensitivity, specificity, and predictive values of the mattress in detecting apneas, hypopneas, and limb movements compared to polysomnography.
Evaluating the agreement between the mattress and polysomnography for sleep variables such as total sleep time, sleep efficiency, sleep stages, micro-arousals, and patient position.
Assessing whether measurement accuracy varies by sleeping position or age group (adults vs. children).
Measuring subjective sleep quality using the Groningen Sleep Quality Scale (GSQS-8).
Performing a descriptive analysis of patient demographics.
Hypotheses:
The smart mattress will detect obstructive sleep apnea, sleep quality, and periodic limb movements with accuracy comparable to polysomnography.
The system will provide a reliable, non-invasive, home-friendly diagnostic method.
Measurements of the apnea-hypopnea index (AHI) and limb movements will show high sensitivity, specificity, and predictive values, both overall and according to OSA severity.
There will be good agreement between mattress measurements and polysomnography for most sleep variables.
Accuracy may vary depending on the patient's sleeping position.
Measurements will correlate well across adults and pediatric patients.
Subjective sleep quality scores (GSQS-8) will be consistent with objective mattress data.
This project seeks to develop a more accurate, accessible, and non-invasive diagnostic system for OSA, combining advanced technology with ease of home use. By training the mattress's AI to recognize sleep patterns and events, it aims to optimize the detection of positional apneas, providing patients with better monitoring, early intervention, and improved quality of life.
This project corresponds to a descriptive, observational, and prospective study whose objective is to validate the functioning, accuracy, and clinical applicability of an intelligent mattress designed for the non-invasive detection of sleep-related respiratory disturbances, in comparison with level I polysomnography (the gold standard for OSA diagnosis). This phase constitutes the first stage of the global project aimed at the diagnosis and treatment of obstructive sleep apnea (OSA) through advanced monitoring and postural-adaptation technologies.
During the period between November 17, 2026, and March 1, 2028, all polysomnographies performed in the Sleep Unit of Hospital San Pedro will be incorporated into a systematic registry together with the data simultaneously generated by the intelligent mattress. The aim is to determine the level of agreement between both systems, validate the diagnostic utility of the mattress, and generate the database required for the subsequent development of artificial intelligence algorithms for the automatic identification of respiratory events and sleep stages.
REGISTRY PROCEDURES AND DATA QUALITY
The centralized registry will include all polysomnographic studies performed with Natus equipment, stored on its internal server, and the parallel recordings from the intelligent mattress. The registry structure will be designed to ensure data traceability, integrity, and quality, with specific procedures for technical validation, clinical verification, and coherence control.
1.1 Quality Assurance Plan
A quality assurance system will be established based on four pillars:
Initial technical validation
Each polysomnography will be reviewed by a sleep technician who will confirm:
Expert clinical review
A certified sleep-medicine specialist will manually score each PSG according to AASM 2022 recommendations, including:
Internal audit
Ten percent of the records will be reviewed by a second independent evaluator to estimate inter-observer agreement. Discrepancies >10% in respiratory indices will trigger consensus sessions.
Mattress data integrity review
The system will automatically verify:
1.2 Automated Data Checks
Mattress and PSG data will be subjected to validation through automated rules:
Range rules:
Internal coherence rules:
Temporal consistency rules:
Records generating alerts will be manually reviewed and classified as:
1.3 Source Data Verification (SDV)
A source-data verification process will be implemented, including:
REGISTRY DATA DICTIONARY
The study will include a comprehensive data dictionary specifying:
Examples:
STANDARD OPERATING PROCEDURES (SOPs)
The study includes documented SOPs for:
Installation, recording, and disconnection of PSG and mattress.
Manual scoring of respiratory and leg events.
Data export, anonymization, and archiving.
Synchronization and technical verification.
Data inconsistency management and queries.
Quality control and internal auditing.
Classification of incomplete records.
Security, privacy, and GDPR compliance.
Each SOP specifies responsibilities, operational steps, acceptance criteria, and incident-handling mechanisms.
SAMPLE SIZE ASSESSMENT
The planned sample size is 500 complete records. This calculation is based on:
- An estimated accessible population of ~700 PSGs in the reference period.
- A 95% confidence level.
MISSING DATA MANAGEMENT PLAN
Missing data will be classified as:
• Technical missing: signal loss, sensor failures.
• Poor-quality missing: valid time <4h.
• Inconsistency missing: impossible ranges or temporal discrepancies.
• Administrative missing: export errors.
Criteria:
- Exclusion of records with valid time <4h.
STATISTICAL ANALYSIS PLAN
The analysis will include:
Pearson or Spearman coefficients between PSG and mattress.
• Agreement:
Bland-Altman analyses for:
- Global AHI.
- Supine/non-supine AHI.
- Periodic limb movements.
-Sleep efficiency.
Diagnostic analysis:
- Sensitivity.
- Specificity.
- PPV.
- NPV.
- ROC curves and AUC.
Predictive models:
- Logistic regression.
Multiple-comparison adjustment:
Benjamini-Hochberg (FDR).
Analysis will be conducted using SPSS and R. The significance level will be α = 0.05.
This collection of procedures ensures the registry meets the necessary requirements for scientific validity, reproducibility, and the future development of automated AI-based models, while maintaining applicable clinical and regulatory standards.
Inclusion Criteria:
Exclusion Criteria:
aroncerol@riojasalud.es+ 34 941 29 80 00 ext. 81864
jlazaro@riojasalud.es+ 34 941 29 80 00 ext. 89864
Logroño, La Rioja 26006, Spain
aroncerol@riojasalud.es+34941298000 ext. 81864
jlazaro@riojasalud.es+34941 29 80 00 ext. 89864
aroncerol@riojasalud.es+34941298000 ext. 81864
jlazaro@riojasalud.es+34941 29 80 00