A privacy and energy-aware federated framework for human activity recognition

Khan, A. R., Manzoor, H. U., Ayaz, F., Imran, M. A. and Zoha, A. (2023) A privacy and energy-aware federated framework for human activity recognition. Sensors, 23(23), 9339. (doi: 10.3390/s23239339) (PMID:38067712) (PMCID:PMC10708886)

Abstract

Human activity recognition (HAR) using wearable sensors enables continuous monitoring for healthcare applications. However, the conventional centralised training of deep learning models on sensor data poses challenges related to privacy, communication costs, and on-device efficiency. This paper proposes a federated learning framework integrating spiking neural networks (SNNs) with long short-term memory (LSTM) networks for energy-efficient and privacy-preserving HAR. The hybrid spiking-LSTM (S-LSTM) model synergistically combines the event-driven efficiency of SNNs and the sequence modelling capability of LSTMs. The model is trained using surrogate gradient learning and backpropagation through time, enabling fully supervised end-to-end learning. Extensive evaluations of two public datasets demonstrate that the proposed approach outperforms LSTM, CNN, and S-CNN models in accuracy and energy efficiency. For instance, the proposed S-LSTM achieved an accuracy of 97.36% and 89.69% for indoor and outdoor scenarios, respectively. Furthermore, the results also showed a significant improvement in energy efficiency of 32.30%, compared to simple LSTM. Additionally, we highlight the significance of personalisation in HAR, where fine-tuning with local data enhances model accuracy by up to 9% for individual users.

• Item Type: Articles
• Keywords: Human activity recognition, wearable sensing, LSTM, CNN, Spiking neural network, federated learning.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Zoha, Dr Ahmed and Khan, Ahsan Raza and Manzoor, Habib Ullah and Imran, Professor Muhammad and Ayaz, Fahad
• Authors: Khan, A. R., Manzoor, H. U., Ayaz, F., Imran, M. A., and Zoha, A.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: Sensors
• Publisher: MDPI
• ISSN: 1424-8220
• ISSN (Online): 1424-8220
• Published Online: 22 November 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Sensors 23(23):9339
• Publisher Policy: Reproduced under a Creative Commons license