Citation

Boborzi L, Decker J, Rezaei R, Schniepp R, Wuehr M. Sensors (Basel) 2024; 24(9).

Copyright

(Copyright © 2024, MDPI: Multidisciplinary Digital Publishing Institute)

DOI

10.3390/s24092665

PMID

38732771

PMCID

PMC11085719

Abstract

Human activity recognition (HAR) technology enables continuous behavior monitoring, which is particularly valuable in healthcare. This study investigates the viability of using an ear-worn motion sensor for classifying daily activities, including lying, sitting/standing, walking, ascending stairs, descending stairs, and running. Fifty healthy participants (between 20 and 47 years old) engaged in these activities while under monitoring. Various machine learning algorithms, ranging from interpretable shallow models to state-of-the-art deep learning approaches designed for HAR (i.e., DeepConvLSTM and ConvTransformer), were employed for classification. The results demonstrate the ear sensor's efficacy, with deep learning models achieving a 98% accuracy rate of classification. The obtained classification models are agnostic regarding which ear the sensor is worn and robust against moderate variations in sensor orientation (e.g., due to differences in auricle anatomy), meaning no initial calibration of the sensor orientation is required. The study underscores the ear's efficacy as a suitable site for monitoring human daily activity and suggests its potential for combining HAR with in-ear vital sign monitoring. This approach offers a practical method for comprehensive health monitoring by integrating sensors in a single anatomical location. This integration facilitates individualized health assessments, with potential applications in tele-monitoring, personalized health insights, and optimizing athletic training regimes.

Language: en

Keywords

*Wearable Electronic Devices; Activities of Daily Living; Adult; Algorithms; deep learning; Deep Learning; ear; Ear/physiology; Female; Human Activities; human activity recognition; Humans; in-ear sensing; inertial sensor; machine learning; Machine Learning; Male; Middle Aged; Monitoring, Physiologic/instrumentation/methods; Motion; vital sign monitoring; Walking/physiology; wearables; Young Adult