Wearable AI in the Era of Large Sensor Models

As an effective approach to understanding the human-centric physical world, Wearable Artificial Intelligence (AI), which leverages multimodal wearable sensors to understand human physiology and behavior, has attracted increasing attention in recent years. However, existing sensor models remain largely siloed by modality and task, lacking a unified paradigm for integrating diverse wearable modalities, training strategies, and achieving robust generalization in real-world applications. Motivated by the success of multimodal foundation models, which learn transferable representations from massive multimodal data, we argue that Large Sensor Models (LSMs), defined as foundation models trained on large-scale and multimodal wearable data, offer a promising pathway toward a more general and scalable framework for wearable AI. In this position paper, we formalize the data substrate underlying LSMs, analyze the unique challenges of large-scale wearable sensing, and articulate two directions: (i) LSMs without language capability and (ii) LSMs with language capability. We further discuss representative application areas that can be unlocked by such models. Through this paper, we encourage the community to explore LSMs as a foundational approach for the next generation of human-centric AI systems.

Towards Generalizable Human Activity Recognition: A Survey

As a critical component of Wearable AI, IMU-based Human Activity Recognition (HAR) has attracted increasing attention from both academia and industry in recent years. Although HAR performance has improved considerably in specific scenarios, its generalization capability remains a key barrier to widespread real-world adoption. For example, domain shifts caused by variations in users, sensor positions, or environments can significantly decrease the performance in practice. As a result, in this survey, we explore the rapidly evolving field of IMU-based generalizable HAR, reviewing 229 research papers alongside 25 publicly available datasets to provide a broad and insightful overview. We first present the background and overall framework of IMU-based HAR tasks, as well as the generalization-oriented training settings. Then, we categorize representative methodologies from two perspectives: (i) model-centric approaches, including pre-training method, end-to-end method, and large language model (LLM)-based learning method; and (ii) data-centric approaches, including multi-modal learning and data augmentation techniques. In addition, we summarize widely used datasets in this field, as well as relevant tools and benchmarks. Building on these methodological advances, the broad applicability of IMU-based HAR is also reviewed and discussed. Finally, we discuss persistent challenges (e.g., data scarcity, efficient training, and reliable evaluation) and also outline future directions for HAR, including the adoption of foundation and large language models, physics-informed and context-aware reasoning, generative modeling, and resource-efficient training and inference. The complete list of this survey is available at https://github.com/rh20624/Awesome-IMU-Sensing, which will be updated continuously.