Tailoring Graph Neural Network-based Flow-guided Localization to Individual Bloodstreams and Activities
Pablo Galván, Filip Lemic, Gerard Calvo Bartra, Sergi Abadal, Xavier Costa Pérez
TL;DR
This work tackles variability in patient bloodstreams and activities that challenge flow-guided nanoscale localization. It extends a state-of-the-art GNN approach by incorporating physiological indicators—height, weight, and heart rate—into extended graph designs (including a master node and probability-edge schemes) and by transforming raw data to reflect different profiles. Hyperparameter tuning shows that the combined extended design substantially improves region-level localization accuracy across most profiles, enabling more reliable, individualized monitoring beyond a resting bloodstream. The findings highlight the importance of tailoring localization systems to individual physiology to enable continuous, real-time medical monitoring with in-body nanodevices.
Abstract
Flow-guided localization using in-body nanodevices in the bloodstream is expected to be beneficial for early disease detection, continuous monitoring of biological conditions, and targeted treatment. The nanodevices face size and power constraints that produce erroneous raw data for localization purposes. On-body anchors receive this data, and use it to derive the locations of diagnostic events of interest. Different Machine Learning (ML) approaches have been recently proposed for this task, yet they are currently restricted to a reference bloodstream of a resting patient. As such, they are unable to deal with the physical diversity of patients' bloodstreams and cannot provide continuous monitoring due to changes in individual patient's activities. Toward addressing these issues for the current State-of-the-Art (SotA) flow-guided localization approach based on Graph Neural Networks (GNNs), we propose a pipeline for GNN adaptation based on individual physiological indicators including height, weight, and heart rate. Our results indicate that the proposed adaptions are beneficial in reconciling the individual differences between bloodstreams and activities.
