Robust PPG Authentication: The Role of Temporal, Individual, and State Variability

Type
Publication
Companion of the 2025 ACM International Joint Conference on Pervasive and Ubiquitous Computing, UbiComp Companion 2025, Espoo, Finland, October 12-16, 2025
publications
Lidia Alecci
Authors
PhD Student
Lidia Alecci is a PhD student at the Faculty of Informatics, Università della Svizzera italiana (USI). Her research uses wearable devices for sleep monitoring, personal health, and much more.
Authors
Former Member
Leonardo Alchieri
Authors
PhD Student
Leonardo Alchieri is a PhD student at the Faculty of Informatics, Università della Svizzera italiana (USI), supervised by Prof. Silvia Santini. His research pursues machine learning for affective, wearable, and ubiquitous computing, with a focus on personal health.
Nouran Abdalazim
Authors
PhD Student
Nouran Abdalazim is a PhD student at the Faculty of Informatics, Università della Svizzera italiana (USI). She works on affective and wearable computing, focusing on personal health and productivity in both the workplace and personal life.
Giovanni De Felice
Authors
Postdoc

I am a postdoctoral researcher at the Faculty of Informatics at the Università della Svizzera Italiana (USI) in Lugano, Switzerland, where I work in Prof. Silvia Santini and Prof. Marc Langheinrich’s group. I hold a Ph.D. in Computer Science from the University of Liverpool (UK) and a Master’s degree in experimental particle physics from the University of Pisa (IT), having conducted my thesis work within the Mu2e experiment at Fermi National Laboratory (US).

My research centers on interpretability-by-design: building deep learning models whose reasoning is interpretable by construction rather than explained after training, which makes them steerable and verifiable. To this end, I work on standardizing the underlying theory and code interfaces and on adding structure to the interpretable intermediate space.

Among data modalities, I focus particularly on time series, including forecasting, classification, representation learning, and virtual sensing, which I study through problems in the natural sciences and physiological signals. I am also a co-creator of the open-source machine learning library PyTorch Concepts.

Silvia Santini
Authors
Professor
Silvia Santini is an Associate Professor at the Faculty of Informatics of USI since September 2016, where she co-leads the People-Centered Computing Lab together with Prof. Marc Langheinrich. From July 2014 until August 2016 she held an Associate Professor position at TU Dresden, where she led the Embedded Systems Lab. From October 2011 until July 2014 she was an Assistant Professor at the Department of Electrical Engineering and Information Technology of TU Darmstadt, Germany, where she led the Wireless Sensor Networks Lab. From 2009 until 2011 she was a postdoctoral researcher in Prof. Friedemann Mattern’s Distributed Systems Group at ETH Zurich, and from November 2010 until February 2011 she joined Leonidas Guibas’s research group at Stanford University as a visiting scholar. Silvia completed her PhD under the supervision of Prof. Friedemann Mattern at ETH Zurich in 2009, and graduated in Telecommunication Engineering (with honors) from the Sapienza University of Rome, Italy, in May 2004.