Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
About

About

With over a decade of dedicated research in the field of sleep medicine, I have developed a strong foundation in both the clinical and epidemiological aspects of this specialty. I use hypotheses, experts, and data to enhance sleep screening, diagnosis, treatment, and monitoring. Passionate about health promotion and disease prevention, I develop strategies empowering individuals to manage their sleep health. Committed to scientific discovery, I strive to make a profound impact in respiratory medicine.

Interest
Topics
Details

Details

  • Name

    Daniela Santos
  • Role

    Assistant Researcher
  • Since

    01st September 2024
004
Publications

2026

A subject-based association network defines new pediatric sleep apnea phenotypes with different odds of recovery after treatment

Authors
Gutiérrez-Tobal, GC; Gomez-Pilar, J; Ferreira-Santos, D; Pereira-Rodrigues, P; Alvarez, D; del Campo, F; Gozal, D; Hornero, R;

Publication
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE

Abstract
Background and objectives: Timely treatment of pediatric obstructive sleep apnea (OSA) can prevent or reverse neurocognitive and cardiovascular morbidities. However, whether distinct phenotypes exist and account for divergent treatment effectiveness remains unknown. In this study, our goal is threefold: i) to define new data-driven pediatric OSA phenotypes, ii) to evaluate possible treatment effectiveness differences among them, and iii) to assess phenotypic information in predicting OSA resolution. Methods: We involved 22 sociodemographic, anthropometric, and clinical data from 464 children (5-10 years old) from the Childhood Adenotonsillectomy Trial (CHAT) database. Baseline information was used to automatically define pediatric OSA phenotypes using a new unsupervised subject-based association network. Follow-up data (7 months later) were used to evaluate the effects of the therapeutic intervention in terms of changes in the obstructive apnea-hypopnea index (OAHI) and the resolution of OSA (OAHI < 1 event per hour). An explainable artificial intelligence (XAI) approach was also developed to assess phenotypic information as OSA resolution predictor at baseline. Results: Our approach identified three OSA phenotypes (PHOSA1-PHOSA3), with PHOSA2 showing significantly lower odds of OSA recovery than PHOSA1 and PHOSA3 when treatment information was not considered (odds ratios, OR: 1.64 and 1.66, 95 % confidence intervals, CI: 1.03-2.62 and 1.01-2.69, respectively). The odds of OSA recovery were also significantly lower in PHOSA2 than in PHOSA3 when adenotonsillectomy was adopted as treatment (OR: 2.60, 95 % CI: 1.26-5.39). Our XAI approach identified 79.4 % (CI: 69.9-88.0 %) of children reaching OSA resolution after adenotonsillectomy, with a positive predictive value of 77.8 % (CI: 70.3 %-86.0 %). Conclusions: Our new subject-based association network successfully identified three clinically useful pediatric OSA phenotypes with different odds of therapeutic intervention effectiveness. Specifically, we found that children of any sex, >6 years old, overweight or obese, and with enlarged neck and waist circumference (PHOSA2) have less odds of recovering from OSA. Similarly, younger female children with no enlarged neck (PHOSA3) have higher odds of benefiting from adenotonsillectomy.

2025

A comparative analysis of unsupervised machine-learning methods in PSG-related phenotyping

Authors
Ghorvei, M; Karhu, T; Hietakoste, S; Ferreira Santos, D; Hrubos Strom, H; Islind, AS; Biedebach, L; Nikkonen, S; Leppaenen, T; Rusanen, M;

Publication
JOURNAL OF SLEEP RESEARCH

Abstract
Obstructive sleep apnea is a heterogeneous sleep disorder with varying phenotypes. Several studies have already performed cluster analyses to discover various obstructive sleep apnea phenotypic clusters. However, the selection of the clustering method might affect the outputs. Consequently, it is unclear whether similar obstructive sleep apnea clusters can be reproduced using different clustering methods. In this study, we applied four well-known clustering methods: Agglomerative Hierarchical Clustering; K-means; Fuzzy C-means; and Gaussian Mixture Model to a population of 865 suspected obstructive sleep apnea patients. By creating five clusters with each method, we examined the effect of clustering methods on forming obstructive sleep apnea clusters and the differences in their physiological characteristics. We utilized a visualization technique to indicate the cluster formations, Cohen's kappa statistics to find the similarity and agreement between clustering methods, and performance evaluation to compare the clustering performance. As a result, two out of five clusters were distinctly different with all four methods, while three other clusters exhibited overlapping features across all methods. In terms of agreement, Fuzzy C-means and K-means had the strongest (kappa = 0.87), and Agglomerative hierarchical clustering and Gaussian Mixture Model had the weakest agreement (kappa = 0.51) between each other. The K-means showed the best clustering performance, followed by the Fuzzy C-means in most evaluation criteria. Moreover, Fuzzy C-means showed the greatest potential in handling overlapping clusters compared with other methods. In conclusion, we revealed a direct impact of clustering method selection on the formation and physiological characteristics of obstructive sleep apnea clusters. In addition, we highlighted the capability of soft clustering methods, particularly Fuzzy C-means, in the application of obstructive sleep apnea phenotyping.

2025

Clinical Annotation and Medical Image Anonymization for AI Model Training in Lung Cancer Detection

Authors
Freire, AM; Rodrigues, EM; Sousa, JV; Gouveia, M; Ferreira-Santos, D; Pereira, T; Oliveira, HP; Sousa, P; Silva, AC; Fernandes, MS; Hespanhol, V; Araújo, J;

Publication
UNIVERSAL ACCESS IN HUMAN-COMPUTER INTERACTION, UAHCI 2025, PT I

Abstract
Lung cancer remains one of the most common and lethal forms of cancer, with approximately 1.8 million deaths annually, often diagnosed at advanced stages. Early detection is crucial, but it depends on physicians' accurate interpretation of computed tomography (CT) scans, a process susceptible to human limitations and variability. ByMe has developed a medical image annotation and anonymization tool designed to address these challenges through a human-centered approach. The tool enables physicians to seamlessly add structured attribute-based annotations (e.g., size, location, morphology) directly within their established workflows, ensuring intuitive interaction.Integrated with Picture Archiving and Communication Systems (PACS), the tool streamlines the annotation process and enhances usability by offering a dedicated worklist for retrospective and prospective case analysis. Robust anonymization features ensure compliance with privacy regulations such as the General Data Protection Regulation (GDPR), enabling secure dataset sharing for research and developing artificial intelligence (AI) models. Designed to empower AI integration, the tool not only facilitates the creation of high-quality datasets but also lays the foundation for incorporating AI-driven insights directly into clinical workflows. Focusing on usability, workflow integration, and privacy, this innovation bridges the gap between precision medicine and advanced technology. By providing the means to develop and train AI models for lung cancer detection, it holds the potential to significantly accelerate diagnosis as well as enhance its accuracy and consistency.

2025

“Counting zzz’s” exploring and evaluating sleep apps across mobile platforms: scoping review (Preprint)

Authors
Araújo, MI; Ferreira-Santos, D;

Publication

Abstract
BACKGROUND

Good sleep is crucial for human life. Research has shown that poor-quality sleep is related to several cardiovascular and metabolic disorders. Sleep disorders are well categorized, and most of them have defined diagnostic criteria, with level 1 polysomnography being the gold standard. With the increasing use of technology, specifically smartphones, in people’s everyday lives, the search for alternative ways of monitoring sleep disorders or certain sleep parameters has been gaining relevance.

OBJECTIVE

This scoping review aims to understand which mobile applications (apps) are available and might be useful in the Portuguese reality and explore their features.

METHODS

A search was performed in Google Play and Apple App Store for mobile applications that monitored sleep cycles, sleep movements, or sound recording and that were available in Portuguese until February 2025. Afterward, a search for scientific evidence of the selected apps was conducted.

RESULTS

Out of the 981 search results obtained, 34 applications met the study’s inclusion criteria. These were then divided into 5 categories according to their main functions: sleep cycle monitoring (SCM), sound recording (SR), SCM&SR, SCM and movement monitoring (MM), and SCM&SR&MM. 23 apps were available in both stores. Almost half of the selected apps (n=15) functioned better or needed wearable devices associated with a more thorough sleep analysis. To be fully operational, none of the mobile apps is entirely free for the user. Most of the applications did not have scientific evidence substantiating their features.

CONCLUSIONS

The mobile applications market is volatile, with little regulation and a lack of scientific evidence available to sustain the accuracy of its products. Even though mobile applications cannot substitute polysomnography in diagnosing sleep disorders, they might be relevant in monitoring sleep since they are easily available and do not require highly specific circumstances to be used. More studies are needed to validate apps, specifically in Portuguese.

2025

Prediction of response to cardiac resynchronization therapy using electrocardiographic criteria: A systematic review; Predição da resposta à terapêutica de ressincronização cardíaca utilizando critérios eletrocardiográficos: revisão sistemática

Authors
Dias Costa, P; Bessa, JP; Canelas Pais, M; Ferreira Santos, D; Montenegro Sá, F; Monteiro Soares, M; Hipólito Reis, A; Martins Oliveira, M; Pereira Rodrigues, P;

Publication
Revista Portuguesa de Cardiologia

Abstract
Background: Cardiac resynchronization therapy (CRT) is an established therapeutic option for heart failure, but despite careful selection around 30% of the patients still do not respond to this therapy. The standard electrocardiogram (ECG) is a practical and inexpensive tool to assess potential responders to CRT but with conflicting evidence regarding the value of different ECG parameters. As such, we conducted a systematic review of real-world studies to assess the value of pre-implantation standard ECG parameters in predicting response to CRT. Methods: We searched on PubMed, Scopus, and Web of Knowledge online databases to identify analytic studies and synthesized results through evidence tables. Results: Sixty-two eligible articles were included in this review. Traditional predictors of response were QRS duration =150 ms and the presence of left bundle branch block morphology. Contemporary ECG parameters, such as the presence of QRS notching or fragmentation, the S wave assessment, the time to intrinsicoid deflection (ID) in lateral leads, and a lead one ratio =12 also showed great potential in assessing response to CRT. Conclusions: This review highlights the promising capability of the standard ECG in predicting response to CRT, particularly when using more contemporary predictors, while emphasizing the necessity for further research to validate the prognostic value of these predictors. © 2025 Elsevier B.V., All rights reserved.