Dimitris Spathis

I am a research scientist at Google and a visiting academic at the University of Cambridge, focusing on building foundation models and adaptive agents for health. My work bridges the gap between fundamental research and real-world application, developing models that are currently used by millions of people worldwide. I am particularly focused on the following areas:

Previously, I was a senior research scientist at Nokia Bell Labs, leading efforts in AI for multimodal health. Before that, I completed a PhD in Computer Science at the University of Cambridge working with Prof. Cecilia Mascolo. During my studies, I was fortunate to work at Microsoft Research, Telefonica Research, and Ocado. I also helped start COVID-19 Sounds, one of the largest studies in audio AI for health.

My research has been published in top venues in artificial intelligence, AI for health, and human-centered signal processing while recent projects have been featured in international media such as the New York Times, BBC, CNN, Guardian, Washington Post, Forbes, and Financial Times (see more in Press).

Selected Works View all publications →

SensorFM & LSM-2

SensorFM & LSM-2: Foundation Models for Wearable Data

Generative models trained on up to one trillion minutes of wearable sensor data, capable of handling incomplete multimodal inputs.

PaPaGei

PaPaGei: Open Foundation Models for Optical Physiological Signals

The first open foundation model for biosignals (PPG) pre-trained on 57,000 hours of data, published at ICLR 2025.

The first step is the hardest

Why do LLMs struggle with temporal data?

Analyzing the pitfalls of representing and tokenizing temporal data for Large Language Models, particularly from sources like mobile sensors or medical records.

COVID-19 Sounds

Looking for audio biomarkers in respiratory recordings

COVID-19 Sounds analyzed respiratory recordings for digital respiratory screening. Released large-scale datasets at NeurIPS 2021.

Cardio-respiratory fitness

Estimating a key longevity biomarker through passive wearable data

Models that predict VO2max/cardio fitness using wearable sensor data in large cohorts, published in Nature Digital Medicine.

Step2Heart & SelfHAR

Self-supervised learning for wearable sensor data

We developed some of the first pre-trained models using self-supervised objectives and applied them to various health-related downstream tasks.

News

aug 2026

The announced Health Guardian tool includes 'blood pressure' and 'insulin resistance trends' and is based on our SensorFM and other models. You can read more here.

jul 2026

We released SensorFM, a foundation model trained on the largest personal health dataset. You can read more here.

may 2026

We published a paper describing the heart sensing model and system that runs on the Pixel Watch.

We announced Google Health, the Google Health Coach, and a new screenless device. You can read more here.

Invited talk at the Machine Intelligence for Health Conference (MI4H), Coventry, UK.

apr 2026

New review in AI fairness in personal and mobile sensing that reviewed the literature from the past 8 years. You can read more here.

Invited talk at the RADAR-base Symposium by Wellcome Trust & King’s College London.

mar 2026

We released a perspective discussing that Wearable Foundation Models Should Go Beyond Static Encoders.

Invited lecture at UCambridge on Foundation Models for Personal Health Signals.

dec 2025

Serving on the Advisory Committee for the Learning from Time Series for Health Workshop at NeurIPS 2025.

sep 2025

Invited talk at AI4Health Industry Day 2025 @ Imperial.

jun 2025

We released the paper of Large Sensor Model 2 (LSM-2), a foundation model trained on 40M hours of wearable data.

may 2025

We are organizing a new workshop EvalComp @ Ubicomp'25 focusing on the future of evals, consider submitting your relevant works!

apr 2025

Time2Lang, a new method to use timeseries foundation models with LLMs, was accepted at CHIL 2025. I also gave an invited talk at Singapore Management University on foundation models for personal health.

feb 2025

Our model averaging for label noise mitigation work was published in Scientific Reports.

jan 2025

🦜 PaPaGei was accepted at ICLR 2025! Our music work was also featured in a Guardian article.

dec 2024

Our 🦜 PaPaGei work received the best paper award at the NeurIPS’24 workshop on Time Series in the Age of Large Models. I also gave an invited lecture at the Aristotle University of Thessaloniki on the topic of foundation models for personal health. Our SoundCollage paper was accepted at ICASSP'25.

nov 2024

I joined Google in London, working within the Consumer Health Research team.

oct 2024

We released 🦜 PaPaGei, the first open foundation model for biosignals (PPG). You can read more here. I was also interviewed by Bloomberg on a newsletter about VO2max.

sep 2024

I was a panel speaker at Cambridge Tech Week. You can watch the segment on Youtube.

aug 2024

StatioCL, a new non-stationary self-supervised model for timeseries was accepted to CIKM 2024.

jul 2024

Our work on how Large Language Models struggle with temporal data was published at JAMIA, and was covered by Techcrunch and LG AI Research. You can read more on this post.

jun 2024

Our work on how Self-Supervised Learning improves fairness was accepted at KDD 2024. We released the paper, code, and a project website. I was also interviewed by Runner's World magazine on a feature article about VO2max - you can read more here.

may 2024

My MedAI talk from earlier this year is now available on Youtube.

apr 2024

I was interviewed by the New York Times for an article on cardio fitness and wearables. Also launched a new Short Papers section at IEEE Pervasive journal - consider submitting your works! In addition, my first patent from a few years ago became public; you can read more here.

mar 2024

The collection of accepted papers at the Human-Centric Representation Learning workshop is available as an Arxiv index.

feb 2024

Co-chaired the Human-Centric Representation Learning workshop at AAAI 2024 in Vancouver, with a great set of papers and keynotes - you can read some highlights of the day at AIhub.org. I also gave an invited keynote at the Health Intelligence workshop of the same conference (here are the slides of the talk).

jan 2024

Gave an invited talk at Cambridge Biomedical Campus as part of the MedAI seminar series.

dec 2023

I authored a corporate blogpost describing our team's recent research. I also joined the editorial board of the IEEE Pervasive Computing journal.

Publications

I have published over 60 papers in top-tier venues including NeurIPS, ICLR, KDD, Nature Digital Medicine, UbiComp, and ICASSP. You can also see the full list on Google Scholar.

2026

Towards a General Intelligence and Interface for Wearable Health Data

Girish Narayanswamy, Maxwell A. Xu, A. Ali Heydari, Samy Abdel-Ghaffar, Marius Guerard, Kara Vaillancourt, Zhihan Zhang, Jake Garrison, Levi Albuquerque, Dimitris Spathis, Hong Yu, Hamid Palangi, Xuhai "Orson" Xu, David G. T. Barrett, Joseph Breda, Jed McGiffin, Yubin Kim, Yuwei Zhang, Naghmeh Rezaei, Samuel Solomon, Karan Ahuja, Tim Althoff, Jake Sunshine, Ming-Zher Poh, Benjamin Yetton, Ari Winbush, Nicholas B. Allen, James M. Rehg, Isaac Galatzer-Levy, Yun Liu, John Hernandez, Anupam Pathak, Conor Heneghan, Yuzhe Yang, Ahmed A. Metwally, Pushmeet Kohli, Mark Malhotra, Shwetak Patel, Xin Liu, Daniel McDuff

arXiv preprint arXiv:2605.22759

Pixel Watch: Robust Heart Rate Sensing from Multipath PPG and On-Device Deep Learning Trained on 10,000 hours of Free-Living and Fitness Data

Daniel Roggen, Megan Walker, Yojan Patel, Shyam Tailor, Dimitris Spathis, Matt Wimmer, Brennan Garrett, Dan Howe, Abhinuv Pitale, Hamed Vavadi, Tien Le, Steve Diamond, Oleksiy Vyalov, Vik Sharma, Pete Richards, Tracy Giest, Erika Siegel, Tuan Phan, Sam Mravca, Derrick Vickers, Benjamin Stone, Katarina Vukosavljevic, Justin Phillips, YongSuk Cho, Stefanie Hollidge, Antony Siahaan, Soren Brage, Shwetak Patel, Robert Harle

IEEE Sensors Letters

(Un)fair devices: Moving beyond AI accuracy in personal sensing

Sofia Yfantidou, Marios Constantinides, Dimitris Spathis, Athena Vakali, Daniele Quercia, Fahim Kawsar

ACM Journal on Responsible Computing

2025

Reliable wrist PPG monitoring by mitigating poor skin sensor contact

Hung Manh Pham, Matthew Yiwen Ho, Yiming Zhang, Dimitris Spathis, Aaqib Saeed, Dong Ma

Scientific Reports

Foundation Models for Biosignals: A Survey

Xiao Gu, Yuxuan Shu, Jinpei Han, Yuxuan Liu, Zhangdaihong Liu, James Anibal, Veer Sangha, Edward Phillips, Bradley Segal, Hang Yuan, Fenglin Liu, Kim Branson, Patrick Schwab, Danielle Belgrave, Lei Clifton, Dimitris Spathis, Vasileios Lampos, A Aldo Faisal, David A Clifton

Preprint

Human Factors and Behavioral Sensing in AI Applications

Marios Constantinides, Dimitris Spathis, Sofia Yfantidou

Human-Centered AI: An Illustrated Scientific Quest, 573-591

Time2Lang: Bridging Time-Series Foundation Models and Large Language Models for Health Sensing Beyond Prompting

Arvind Pillai, Dimitris Spathis, Subigya Nepal, Amanda C Collins, Daniel M Mackin, Michael V Heinz, Tess Z Griffin, Nicholas C Jacobson, Andrew Campbell

Conference on Health, Inference, and Learning (CHIL 2025)

Learning under label noise through few-shot human-in-the-loop refinement

Aaqib Saeed, Dimitris Spathis, Jungwoo Oh, Edward Choi, Ali Etemad

Scientific Reports 15 (1), 4276

2024

WellComp 2024: Seventh International Workshop on Computing for Well-Being

Ting Dang, Shkurta Gashi, Dimitris Spathis, Alexander Hoelzemann

ACM Intl. Joint Conf. Pervasive and Ubiquitous Computing (Ubicomp 2024)

FairComp: 2nd International Workshop on Fairness and Robustness in Machine Learning for Ubiquitous Computing

Lakmal Meegahapola, Dimitris Spathis, Marios Constantinides, Han Zhang, Sofia Yfantidou, Niels van Berkel, Anind K. Dey

ACM Intl. Joint Conf. Pervasive and Ubiquitous Computing (Ubicomp 2024)

2023

A Summary of the ComParE COVID-19 Challenges

Alican Akman, Harry Coppock, Christian Bergler, Maurice Gerczuk, Chloë Brown, Jagmohan Chauhan, Andreas Grammenos, Apinan Hasthanasombat, Dimitris Spathis, Tong Xia, Pietro Cicuta, Jing Han, Shahin Amiriparian, Alice Baird, Lukas Stappen, Sandra Ottl, Panagiotis Tzirakis, Anton Batliner, Cecilia Mascolo, Björn Wolfgang Schuller

Frontiers in Digital Health

2022

2021

2020

2019

Pre-PhD (2013-2018)

Theses

Patents

Methods for training foundation models for processing optical physiological signals

US20260093979A1 (filed 2025, published 2026)

Training a machine learning model

US20260119980A1 (filed 2024, published 2026)

Apparatus & method for federated learning

US20250209343A1 (filed 2024, published 2025)

Reuse of data for training machine learning models

US20250156763A1 (filed 2024, published 2025)

Apparatus & method for generating feature embeddings

US20240273404A1 (filed 2023, published 2024)

Apparatus, method, and computer program for transfer learning

US20240127057A1 (filed 2022, published 2024)

Academic service

Leadership & organizer roles:

Expert reviewer & advisory roles:

Program Committee Member: AAAI, IJCAI, KDD, FAccT, SIAM SDM, Sensiblend @ Ubicomp.

Reviewer: NeurIPS, ICLR, ICML, AAAI, IJCAI, KDD, CHI, Ubicomp/IMWUT, CHIL, Nature Digital Medicine, WACV, Nature Scientific Reports, ICASSP, Expert Systems with Applications, Neurocomputing, WWW/The Web Conference, Engineering Applications of Artificial Intelligence, ICWSM, and more.

I have also been a teaching assistant for the following undergraduate courses:

Team

Over the years, I've had the privilege of supervising and closely collaborating with a talented group of researchers, both through industry internships and university PhD co-supervision. We focus on building intelligent and personalized agents for health. Here are the amazing researchers who have worked with me:

Invited talks & lectures

may 2026

Foundation Models for Personal Health Signals
Machine Intelligence for Health Conference (MI4H), Coventry, UK

apr 2026

Foundation Models for Personal Health Signals
RADAR-base Symposium, Wellcome Trust & King’s College London, UK

mar 2026

Foundation Models for Personal Health Signals
University of Cambridge, UK

sep 2025

AI4Health Industry Day 2025
Imperial College London, UK

apr 2025

Foundation models for personal health
Singapore Management University, Singapore

dec 2024

The era of foundation models – AI for personal health as its ultimate use case
Aristotle University, Thessaloniki, Greece

sep 2024

Evidence from industry – what are you really using AI for? (panel)
Cambridge Tech Week, Cambridge, UK

feb 2024

Multimodal AI for Real-World Signals and the Role of Language
AAAI'24 Health Intelligence workshop, Vancouver, Canada

jan 2024

Multimodal, data-efficient, and robust AI for real-world biosignals & the role of generative models
Cambridge MedAI Seminar Series, Biomedical Campus, Cambridge, UK

nov 2023

Multimodal AI for real-world signals – does the key to specialized models lie in language?
Microsoft AI & Pizza talk - Cambridge ELLIS Unit, Cambridge, UK

mar 2023

Human-centric AI for health signals with applications in fitness and activity modeling
Cambridge Public Health symposium, Cambridge, UK

feb 2023

Self-Supervised Learning for Health Signals
Rising Stars in AI, KAUST, Saudi Arabia

nov 2022

Representation learning for cardio-fitness prediction in free-living environments
King's College London, Precision Health Informatics Data Lab, London, UK

jun 2022

AI-powered Wearables Transforming Mobile Health
AI Summit, London Tech week, London, UK

mar 2022

Self-supervised learning for health signals
Feinstein Institutes of Northwell Health, New York, USA (remote)

mar 2021

AI to model Human Behaviour and Health
Jesus College Postgraduate Conference, virtual event, UK

mar 2019

Deep sequence learning for large-scale inference of human behaviour from mobile sensor data
MRC Epidemiology Unit, University of Cambridge, UK

oct 2018

Fast, Visual and Interactive Semi-supervised Dimensionality Reduction
Facebook PhD Open House, London, UK

Press & media coverage

AI for physiological sensing, Pixel Watch & Fitbit Air: PCMag, Wired, Engadget, 9to5Google, ZDNet, Tom's Guide, The Verge, NYT Wirecutter, DC Rainmaker, Engadget, Android Authority, CNET, Men's Health, PCMag, Wired.

Large Language Models for timeseries: Techcrunch, LG AI Research.

Audio AI for COVID-19: Cambridge University (1), (2), (3), (4), BBC, The Guardian, Financial Times, The Times, Forbes, Slate, Huffington Post, DailyMail, ITV, IEEE Spectrum, TheNextWeb, STAT, EPFL, TheScientist, The Register, KDnuggets, NPR/WBUR, Psychology Today, El Pais, RAI, Corriere della Sera, Focus, DerStandard.

AI for VO2max: Cambridge University (1), (2), New York Times, Bloomberg, VentureBeat, Business Insider, Runner's World, Communications of the ACM, Daily Mirror, Bicycling Magazine, Owkin, Spektrum.de.

Data-driven music psychology: Cambridge University, The Times, Washington Post, CNN, The Telegraph, Sky News, Guardian, ITV, DailyMail, Inc., CTV, ZDF, Der Tagesspiegel, ABC.ES, ABC.AU, ELLE, Cosmopolitan, RTBF, TEDx.

Interviews: IndiaAI.gov

Playground

“The next big thing in technology often starts off looking like a toy”

Quantifying name-dropping

Communitypoprefs.com is a data visualization website, where we present every pop-culture reference over the course of 5 seasons of the TV series Community.

Map out your music taste on Spotify

Visualizing my favourite songs on Spotify with dimensionality reduction and anomaly detection. Data essay published in Cuepoint Magazine, Medium's premier music publication.

Children books and childish language?

Text mining Game of Thrones, Harry Potter, Hunger Games and Lord of the Rings books. Data essay featured in Medium's Editor Picks.

Anonymize kids' faces before posting online

Mobile app with face recognition, age estimation, & emotion recognition to blur kids or replace their face with emotion-based emoji. Developed during HackZurich 2018.

Discover top local news globally

Glocalne.ws was a mashup of Google News and Google Maps. Unfortunately it is now defunct due to API discontinuance.

Composing music and text with Recurrent Neural Networks

Training neural networks on massive amounts of musical notation and literature and letting them create their own art. Essay in Greek but you can still see/listen to the results.

Personal

Non-academic things about me: I love music, both playing and listening. I am mostly into art rock and indie folk, with the occasional exception of some well-crafted pop. Although I am an accordionist by training, over the last few years I've been playing mostly piano and ukulele. In a previous life, I performed with the critically acclaimed band The Children of the Oldness (aka Kore Ydro) and recorded the album "Consortium in Amato" (listen here).

I also enjoy street photography and in particular playing with light—photography comes from Greek φως (light) and γραφή (writing), or drawing with light. A sample of my shots is on Flickr and one of my landscapes was featured in the Huffington Post.

Lastly, and perhaps most importantly, I'm always on the lookout for ways to move items from the "non-academic list" to the "academic list"—let me know if you'd like to help!