The BioRobotics Institute, Scuola Superiore Sant'Anna, 56025, Pisa, Italy.
Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, 56025, Pisa, Italy.
Sci Rep. 2021 Dec 1;11(1):23239. doi: 10.1038/s41598-021-02553-z.
Microrobots (MRs) have attracted significant interest for their potentialities in diagnosis and non-invasive intervention in hard-to-reach body areas. Fine control of biomedical MRs requires real-time feedback on their position and configuration. Ultrasound (US) imaging stands as a mature and advantageous technology for MRs tracking, but it suffers from disturbances due to low contrast resolution. To overcome these limitations and make US imaging suitable for monitoring and tracking MRs, we propose a US contrast enhancement mechanism for MR visualization in echogenic backgrounds (e.g., tissue). Our technique exploits the specific acoustic phase modulation produced by the MR characteristic motions. By applying this principle, we performed real-time visualization and position tracking of a magnetic MR rolling on a lumen boundary, both in static flow and opposing flow conditions, with an average error of 0.25 body-lengths. Overall, the reported results unveil countless possibilities to exploit the proposed approach as a robust feedback strategy for monitoring and tracking biomedical MRs in-vivo.
微机器人（MRs）在难以到达的身体部位的诊断和非侵入性干预方面具有很大的潜力，引起了人们的极大兴趣。生物医学 MRs 的精细控制需要实时反馈其位置和配置。超声（US）成像作为一种成熟且有利的 MRs 跟踪技术，但由于对比度分辨率低而受到干扰。为了克服这些限制，使 US 成像适合于监测和跟踪 MRs，我们提出了一种用于在超声回波背景（例如组织）中显示 MR 的超声对比度增强机制。我们的技术利用了由 MR 特征运动产生的特定声相位调制。通过应用这一原理，我们在静态和反向流动条件下对在管腔边界上滚动的磁性 MR 进行了实时可视化和位置跟踪，平均误差为 0.25 个体长。总的来说，所报道的结果揭示了无数的可能性，可以利用所提出的方法作为一种强大的反馈策略，用于监测和跟踪体内生物医学 MRs。
