Exploring the Hidden Complexity: Entropy Analysis in Pulse Oximetry of Female Athletes

• Published in: Biosensors (Basel) Vol. 14; no. 1; p. 52
• Main Authors: Cabanas, Ana M, Fuentes-Guajardo, Macarena, Sáez, Nicolas, Catalán, Davidson D, Collao-Caiconte, Patricio O, Martín-Escudero, Pilar
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-01-2024; MDPI
• Subjects: Analysis; approximate entropy; Athletes; Biosensors; Blood pressure; Body mass index; Cardiorespiratory fitness; Coefficient of variation; Complexity; Demographic aspects; Dynamical systems; Entropy; Evaluation; Exercise; Female; Females; Fitness; Fitness equipment; Heart rate; Humans; Innovations; Life expectancy; Oximetry; Oxygen; Oxygen consumption; Oxygen saturation; Physical fitness; Physiological aspects; Physiological responses; Physiology; pulse oximeter; Pulse oximetry; Running; sample entropy; Sensors; Time series; VO2,max; Warm up (exercise); Women athletes; Women's fitness; Womens health; women’s response to exercise; Chile; women’s response to exercise; pulse oximeter; approximate entropy; VO2,max; sample entropy
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios14010052

This study examines the relationship between physiological complexity, as measured by Approximate Entropy (ApEn) and Sample Entropy (SampEn), and fitness levels in female athletes. Our focus is on their association with maximal oxygen consumption (VO2,max). Our findings reveal a complex relationship between entropy metrics and fitness levels, indicating that higher fitness typically, though not invariably, correlates with greater entropy in physiological time series data; however, this is not consistent for all individuals. For Heart Rate (HR), entropy measures suggest stable patterns across fitness categories, while pulse oximetry (SpO2) data shows greater variability. For instance, the medium fitness group displayed an ApEn(HR) = 0.57±0.13 with a coefficient of variation (CV) of 22.17 and ApEn(SpO2) = 0.96±0.49 with a CV of 46.08%, compared to the excellent fitness group with ApEn(HR) = 0.60±0.09 with a CV of 15.19% and ApEn(SpO2) =0.85±0.42 with a CV of 49.46%, suggesting broader physiological responses among more fit individuals. The larger standard deviations and CVs for SpO2 entropy may indicate the body's proficient oxygen utilization at higher levels of physical demand. Our findings advocate for combining entropy metrics with wearable sensor technology for improved biomedical analysis and personalized healthcare.