Human activity recognition (HAR) from wearable sensor data traditionally identifies atomic movements (e.g., sit, stand, walk). However, many medical fields require recognizing functional activities-higher-level, goal-directed behaviors (e.g., errands, socialize, work). Functional activity recognition is critical for cognitive health assessment, rehabilitation, post-surgical recovery, and chronic disease management, yet remains largely unexplored due to its inherent complexity and variability for in-the-wild settings. This work addresses these challenges by investigating methods for functional HAR and introducing a novel approach that augments feature representations with feature token-transformer embeddings to improve classification performance. We compare a range of machine learning and deep learning methods, analyzing their ability to generalize across a diverse population. Additionally, we present ArWISE, a large-scale functional activity dataset collected longitudinally from n = 503 participants, consisting of over 32 million labeled points. Our experiments demonstrate the advantages of incorporating feature embeddings into functional HAR models, particularly in handling real-world variability and data sparsity. By bridging the gap between atomic movement recognition and functional behavior modeling, this work lays the foundation for more advanced, behavior-aware applications in digital health and human-centered AI.

This article introduces RAS, a cyber-physical system that supports individuals with memory limitations to perform daily activities in their own homes. RAS represents a partnership between a smart home, a robot, and software agents. When smart home residents perform activities, RAS senses their movement in the space and identifies the current activity. RAS tracks activity steps to detect omission errors. When an error is detected, the RAS robot finds and approaches the human with an offer of assistance. Assistance consists of playing a video recording of the entire activity, showing the omitted activity step, or guiding the resident to the object that is required for the current step. We evaluated RAS performance for 54 participants performing three scripted activities in a smart home testbed and for 2 participants using the system over multiple days in their own homes. In the testbed experiment, activity errors were detected with a sensitivity of 0.955 and specificity of 0.992. RAS assistance was performed successfully with a rate of 0.600. In the in-home experiments, activity errors were detected with a combined sensitivity of 0.905 and a combined specificity of 0.988. RAS assistance was performed successfully for the in-home experiments with a rate of 0.830.

One of major challenges in chronic disease self-management is the lack of medication adherence. Despite the proliferation of mobile technologies, the potential of using pervasive computing solutions for improved medication management has remained almost unexplored. In this paper, we present a smart-phone based system capable of delivering adaptive activity-aware medication reminders by learning the user's activity of daily living and detecting the most appropriate and effective timing for medication reminders centered around the initial user-specified schedule.

Recent progress in Internet of Things (IoT) platforms has allowed us to collect large amounts of sensing data. However, there are significant challenges in converting this large-scale sensing data into decisions for real-world applications. Motivated by applications like health monitoring and intervention and home automation we consider a novel problem called Activity Prediction, where the goal is to predict future activity occurrence times from sensor data. In this paper, we make three main contributions. First, we formulate and solve the activity prediction problem in the framework of imitation learning and reduce it to a simple regression learning problem. This approach allows us to leverage powerful regression learners that can reason about the relational structure of the problem with negligible computational overhead. Second, we present several metrics to evaluate activity predictors in the context of real-world applications. Third, we evaluate our approach using real sensor data collected from 24 smart home testbeds. We also embed the learned predictor into a mobile-device-based activity prompter and evaluate the app for nine participants living in smart homes. Our results indicate that our activity predictor performs better than the baseline methods, and offers a simple approach for predicting activities from sensor data.

We consider a novel problem called Activity Prediction, where the goal is to predict the future activity occurrence times from sensor data. In this paper, we make three main contributions. First, we formulate and solve the activity prediction problem in the framework of imitation learning and reduce it to simple regression learning problem. This approach allows us to leverage powerful regression learners; is easy to implement; and can reason about the relational and temporal structure of the problem with negligible computational overhead. Second, we present several evaluation metrics to evaluate a given activity predictor, and discuss their pros and cons in the context of real-world applications. Third, we evaluate our approach using real sensor data collected from 24 smart home testbeds. We also embed the learned predictor into a mobile device based activity prompter and evaluate the app on multiple participants living in smart homes. Our experimental results indicate that the activity predictor learned with our approach performs better than the baseline methods, and offers a simple and reliable approach to prediction of activities from sensor data.