A2 Refereed review article in a scientific journal
Wearable-Based Emotion Recognition Using Electrocardiogram and Galvanic Skin Response and Instrumentation Audit: A Systematic Review; 
Authors: Kosal Bulbul, Ayse; Irfan, Muhammad; Jaakkola, Maria K.; Subasi, Abdulhamit; Klén, Riku
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Publication year: 2026
Journal: IEEE Transactions on Instrumentation and Measurement
Article number: 2512216
Volume: 75
ISSN: 0018-9456
eISSN: 1557-9662
DOI: https://doi.org/10.1109/TIM.2026.3701198
Publication's open availability at the time of reporting: Open Access
Publication channel's open availability : Partially Open Access publication channel
Web address : https://doi.org/10.1109/tim.2026.3701198
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/526591462
Self-archived copy's licence: CC BY
Self-archived copy's version: Publisher`s PDF
Simple and unobtrusive wearables, particularly watches and wristbands, now provide continuous monitoring with no inconvenience and are widely used by elderly people. Effective emotion recognition relies not only on advances in models but also on methods for signal acquisition and specification. In response to this imperative, we performed a systematic review of emotion recognition utilising wearable physiological signals, focusing on two practical modalities: electrocardiography (ECG), which indicates cardiac dynamics and emotional arousal, and galvanic skin response (GSR), a measure of electrodermal activity (EDA) reflecting sympathetic nervous system activation and conveniently recordable at the wrist, which reflects sympathetic nervous system activation and can be conveniently recorded at the wrist. We examined four prominent publishers (ScienceDirect, SpringerLink, Taylor & Francis Online, IEEE Xplore) and identified 549 papers; after excluding 90 review articles and 75 papers focused solely on electroencephalography (EEG), 384 were subjected to thorough screening. After excluding 20 studies focused solely on stress and 316 papers without ECG/GSR data, 48 studies utilising machine learning were identified (2019–2025). Traditional models like support vector machines remain prevalent, though deep learning techniques, particularly convolutional neural networks (CNNs) and hybrids, are more effective at discerning complex temporal patterns. Simultaneously, we conduct an instrumentation and measurement (I&M) audit on commonly utilised datasets. Protocols and sampling rates are generally documented; however, essential measurement details are frequently absent: electrode type and positioning, skin–electrode impedance, signal quality indices (SQIs), calibration, repeatability, and interdevice comparability. These limitations hinder equitable performance attribution (sensing versus modelling), limit uncertainty assessment, and complicate hardware transfer and cross-study evaluation. Standardising I&M metadata in public releases, when combined with AI evaluation practices, improves comparability and dependability in healthcare predictions based on wearable physiological information.
Keywords:
ECG, GSR, I&M, Wearable emotion recognition
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Funding information in the publication:
This work was supported by the AI4HOPE Project under Grant (EU Horizon Project ID 101136769), 2025. The work of Muhammad Irfan and Maria K. Jaakkola was supported in part by the Finnish Cultural Foundation, the Juhani Aho Foundation, and the State Research Funding (VTR) and in part by Shanghai Sci-tech Co-research Program Project under Grant 25HB2703300.
