Reliable Machine Learning for Wearable Activity Monitoring: Novel Algorithms and Theoretical Guarantees

Wearable devices are becoming popular for health and activity monitoring. The machine learning (ML) models for these applications are trained by collecting data in a laboratory with precise control of experimental settings. However, during real-world deployment/usage, the experimental settings (e.g., sensor position or sampling rate) may deviate from those used during training. This discrepancy can degrade the accuracy and effectiveness of the health monitoring applications. Therefore, there is a great need to develop reliable ML approaches that provide high accuracy for real-world deployment. In this paper, we propose a novel statistical optimization approach referred as StatOpt that automatically accounts for the real-world disturbances in sensing data to improve the reliability of ML models for wearable devices. We theoretically derive the upper bounds on sensor data disturbance for StatOpt to produce a ML model with reliability certificates. We validate StatOpt on two publicly available datasets for human activity recognition. Our results show that compared to standard ML algorithms, the reliable ML classifiers enabled by the StatOpt approach improve the accuracy up to 50% in real-world settings with zero overhead, while baseline approaches incur significant overhead and fail to achieve comparable accuracy.

1 Introduction

Wearable devices that combine multiple sensors, low-power processors, and communication capabilities have the potential to trans-form fitness, rehabilitation, and health monitoring [23], [24], [26]. Human activity recognition (HAR) is an important component of these applications since it enables fine-grained understanding of the users’ activity patterns [16], [24], [35]. For instance, knowing the activity patterns is critical in providing personalized treatment to Parkinson’s disease patients [24]. The wide applicability of HAR has led to increased attention in the development of HAR algorithms.