  Objective: The objective of this work is an attempt towards non-contact
freehand 3D ultrasound imaging with minimal complexity added to the existing
point of care ultrasound (POCUS) systems. Methods: This study proposes a novel
approach of using a mechanical track for non-contact ultrasound (US) scanning.
The approach thus restricts the probe motion to a linear plane, to simplify the
acquisition and 3D reconstruction process. A pipeline for US 3D volume
reconstruction employing an US research platform and a GPU-based edge device is
developed. Results: The efficacy of the proposed approach is demonstrated
through ex-vivo and in-vivo experiments. Conclusion: The proposed approach with
the adjustable field of view capability, non-contact design, and low cost of
deployment without significantly altering the existing setup would open doors
for up gradation of traditional systems to a wide range of 3D US imaging
applications. Significance: Ultrasound (US) imaging is a popular clinical
imaging modality for the point-of-care bedside imaging, particularly of the
wrist/knee in the pediatric population due to its non-invasive and radiation
free nature. However, the limited views of tissue structures obtained with 2D
US in such scenarios make the diagnosis challenging. To overcome this, 3D US
imaging which uses 2D US images and their orientation/position to reconstruct
3D volumes was developed. The accurate position estimation of the US probe at
low cost has always stood as a challenging task in 3D reconstruction.
Additionally, US imaging involves contact, which causes difficulty to pediatric
subjects while monitoring live fractures or open wounds. Towards overcoming
these challenges, a novel framework is attempted in this work.
