Related Experiment Video
Updated: Aug 13, 2026

A Model to Simulate Clinically Relevant Hypoxia in Humans
Published on: December 22, 2016
Oxygen saturation regularity analysis in the diagnosis of obstructive sleep apnea
Félix del Campo1, Roberto Hornero, Carlos Zamarrón
1Hospital del Río Hortega, Servicio de Neumología, C/Cardenal Torquemada s/n, 47010 Valladolid, Spain. fsas@telefonica.net
Objective:
The present study assessed the validity of approximate entropy (ApEn) analysis of arterial oxygen saturation (SaO(2)) data obtained from pulse oximetric recordings as a diagnostic test for obstructive sleep apnea (OSA) in patients clinically suspected of suffering this disease.
Methodology:
A sample of 187 referred outpatients, clinically suspected of having OSA, was studied using nocturnal pulse oximetric recording performed simultaneously with complete polysomnography. ApEn analysis was applied to SaO(2) data.
Results:
Patients with OSA presented significantly higher approximate entropy levels than those without OSA (1.08+/-0.30 versus 0.47+/-0.26). Apnea-hypopnea index was correlated significantly with ApEn (r=0.607; p<0.001). Using receiver operating characteristic curve analysis, we obtained a diagnostic sensitivity of 88.3% and specificity of 82.9%, positive predictive value of 88.3% and a negative predictive value of 82.9%, at a threshold of 0.679. As a diagnostic test, this method presents high sensitivity and specificity compared to traditional methods in the diagnosis of OSA.
Conclusion:
We conclude that ApEn analysis of SaO(2) data obtained from pulse oximetric recordings could be useful as a diagnostic technique for OSA subjects.
Related Concept Videos
Special considerations while measuring oxygen saturation
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is important.
Pulse Oximetry
Purpose
Average SpO2 values are greater than 95%. If the readings fall below 90%, it indicates that...
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
Sleep Apnea
The condition is more prevalent among...
Guidelines For Measuring Vital Signs
Before taking a patient's vital signs, a nurse would consider and assess the patient's comfort level and ensure appropriate equipment is available.
Respiratory Volumes and Capacities I
