Sensorless 3-D Ultrasound Reconstruction via Embedded Patterns: A Low-Cost Framework

Hand-held three-dimensional (3D) ultrasound (US) imaging offers critical advantages over conventional two-dimensional (2D) systems by providing richer spatial context and more reliable volumetric measurements for diagnosis and interventions. However, existing 3D US solutions either rely on costly external tracking systems or suffer from cumulative drift errors in purely image-based methods. To address these limitations, we propose a novel, low-cost sensorless 3D US framework that integrates a custom coupling device with a coarse-to-fine optimization algorithm for robust pose refinement. The coupling device embeds geometrically structured patterns into the US images, enabling accurate probe pose estimation directly from image content and supporting reliable volumetric reconstruction. Validation using simulations, phantoms, andin vivocarotid artery studies confirms the method’s accuracy: 2.4% average drift rate in simulations, 2.4% volumetric error and linear measurement error of 0.07 mm, 0.11 mm, and 0.22 mm for lateral, axial and elevational directions in phantoms, and anatomical fidelity comparable to commercial 3D probesin vivo. By removing the need for expensive external tracking or specialized US probes and enhancing robustness over existing image-based methods, our approach improves the accessibility of 3D US imaging, particularly in resource-constrained clinical settings.