Authors: Dageon Oh, Guan-Yu Wu
Department of Mechanical Engineering, UW-Madison
- Summary:
We aim to design and fabricate a 3D-printed probe holder that enables stable and repeatable large-area ultrasound scanning using a Verasonics imaging system. By improving probe positioning and scanning consistency, the proposed system is expected to reduce operator-dependent variability and support the feasibility of frame-based 3D ultrasound reconstruction when imaging large materials.
- Intro/Background:
Ultrasound imaging is widely used in biomedical and material imaging because it is non-invasive, relatively inexpensive, and capable of providing real-time internal structural information. In recent years, there has been growing interest in reconstructing three-dimensional (3D) volumes from sequential two-dimensional (2D) ultrasound images, as 3D visualization can provide more comprehensive spatial information compared with conventional 2D imaging. However, many ultrasound imaging procedures still rely on manual freehand scanning, where the operator moves the probe across the target region while collecting image frames. This process often introduces inconsistencies in probe motion, orientation, and contact force, which can lead to spatial positioning errors and reduced reconstruction accuracy. As a result, improving scanning stability and repeatability is an important challenge for enabling reliable large-area ultrasound imaging and potential volumetric reconstruction.
Several studies have attempted to address these limitations through tracking technologies and robotic scanning systems. For example, Ma et al. developed a freehand 3D ultrasound system that integrates a probe-mounted camera and QR-code-based visual tracking combined with ORB-SLAM algorithms to improve probe localization accuracy during scanning. Their results showed that external visual positioning can significantly reduce cumulative spatial errors during freehand ultrasound acquisition. Additionally, robotic ultrasound systems have been proposed to improve scanning consistency. Sun et al. introduced an autonomous robotic ultrasound framework capable of performing stable scanning using hybrid position–force control and deep learning-based reconstruction methods. Similarly, Wu et al. developed a robotic end-effector designed to maintain a constant probe–tissue contact force, highlighting the importance of controlled probe positioning and interaction for reliable imaging. While these approaches improve imaging repeatability, they often require complex robotic systems, external tracking hardware, or sophisticated control algorithms, which may increase system cost and limit accessibility. Therefore, there is a need for simpler and more affordable stabilization approaches that can improve scanning consistency during large-area ultrasound imaging without requiring complex robotic infrastructure.
- Impact:
If successful, this project will provide a simple and affordable solution to improve the stability and repeatability of ultrasound scanning for large-area imaging. By introducing a mechanically stabilized 3D-printed probe holder, the proposed system can reduce operator-dependent variability that commonly occurs during manual ultrasound scanning. Improved scanning consistency will enable more reliable acquisition of sequential ultrasound frames, which may support volumetric reconstruction and large-area visualization of materials or biological samples. This capability is particularly valuable for applications where consistent imaging across extended regions is required.
More broadly, the proposed approach offers a practical alternative to complex robotic or tracking-based ultrasound systems. While many current solutions rely on robotic manipulators, external tracking cameras, or sophisticated control algorithms to stabilize probe motion, these systems can be costly and difficult to implement in typical research environments. In contrast, a lightweight and low-cost 3D-printed holder could be easily integrated with existing ultrasound platforms such as the Verasonics system. The modular design of the holder will also allow adaptation to different ultrasound probes, making the system flexible and broadly applicable across various imaging configurations. By lowering the technical and financial barriers to stable ultrasound scanning, this project may help expand the accessibility of large-area ultrasound imaging and support further research in ultrasound-based imaging, biomedical engineering, and material characterization.
- Methods/Approach:
This project focuses on developing a mechanically stabilized ultrasound probe holder that enables consistent large-area scanning using a Verasonics ultrasound imaging system. The proposed system will be designed and fabricated using 3D printing to ensure low cost, rapid prototyping, and easy customization. The holder will secure the ultrasound probe and guide its motion during scanning to minimize variations in probe orientation, positioning, and contact with the imaging surface. The design will follow a modular structure so that the holder can be adapted to different ultrasound probe geometries, allowing compatibility with multiple probes used with the Verasonics system.
The research will proceed in several stages. First, a computer-aided design (CAD) model of the probe holder will be developed to ensure stable probe alignment and smooth scanning motion across a large imaging region. The design will incorporate adjustable probe mounts or interchangeable inserts so that probes with different shapes or sizes can be accommodated. The holder will then be fabricated using a 3D printer and assembled for integration with the Verasonics imaging platform. Once fabricated, ultrasound imaging experiments will be performed by scanning large material samples while acquiring sequential B-mode image frames. The stability of the scanning motion will be evaluated by comparing image consistency and positional alignment across frames.
To explore the potential for volumetric imaging, the sequential ultrasound frames obtained during scanning will be organized and analyzed to assess the feasibility of frame-based 3D reconstruction. The main novelty of the proposed approach lies in providing a simple, low-cost mechanical stabilization solution that can improve scanning repeatability without requiring complex robotic systems, external tracking devices, or advanced control algorithms. Compared with existing robotic ultrasound systems, the proposed method is easier to implement and more accessible for typical laboratory environments.
Potential risks include insufficient scanning stability or limited compatibility with certain probe geometries. To mitigate these risks, the holder design will allow iterative modifications through rapid 3D printing, and multiple design versions will be tested to optimize probe fixation and scanning smoothness. This iterative design process will ensure that the system achieves sufficient stability to support consistent large-area ultrasound imaging.
- Future plan:
If the proposed probe holder successfully improves scanning stability and enables consistent large-area ultrasound image acquisition, the next step of this research will focus on expanding the system toward more advanced volumetric imaging capabilities. Sequential ultrasound frames collected during scanning can be further processed using frame registration and stacking techniques to perform more robust 3D ultrasound reconstruction. Future work may also explore the integration of simple positional tracking or motion estimation methods to improve spatial alignment between frames and enhance reconstruction accuracy.
In addition, the modular design of the probe holder provides opportunities to extend the system to a broader range of ultrasound imaging applications. Future developments could include adapting the holder to different ultrasound probes, integrating motorized scanning mechanisms for semi-automated acquisition, or applying the system to biological tissue imaging and material characterization studies. By progressively incorporating these capabilities, the proposed platform could evolve into a flexible and accessible tool for large-area ultrasound imaging and volumetric reconstruction in both biomedical and engineering research environments.