This letter presents MAMMOBOT, one of the first millimetre-scale steerable soft growing robots for medical applications. MAMMOBOT aims to access the breast through the nipple and navigate the mammary ducts to detect precursors of invasive breast cancers. Addressing limitations of the state-of-the-art, MAMMOBOT maintains a hollow inner lumen throughout its soft body, enabling the passing of instruments such as miniature endoscopes, biopsy needles, and optical probes for in situ histopathology. MAMMOBOT is developed by a novel manufacturing approach entailing dual LDPE sheet adhesion with localised heat treatment. MAMMOBOT's steerability is achieved through a sub-millimetre profiled tendon-driven catheter that passes through its inner lumen. A duty cycle controller governs steering versus growing to achieve navigation in complex environments within a human-in-the-loop framework. Benchtop experimental evaluation demonstrates the robot's capabilities and agreement with a Reduced-Order Mode (ROM) of its dynamics. Finally, experimental evaluation on a bespoke breast phantom developed for the purposes of this project demonstrates the clinical relevance and potential impact of MAMMOBOT.

中文翻译：

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MAMMOBOT：微型可控的软成长机器人，用于早期乳腺癌的检测

这封信介绍了MAMMOBOT，这是首批用于医疗应用的毫米级可转向软生长机器人之一。MAMMOBOT旨在通过乳头进入乳房并导航乳腺导管，以检测浸润性乳腺癌的前体。面对最新技术的局限性，MAMMOBOT在其整个软体内部均保持中空的内腔，从而使诸如微型内窥镜，活检针和光学探头等仪器得以通过原位组织病理学。MAMMOBOT是通过一种新颖的制造方法开发的，该方法需要通过局部热处理实现双LDPE片材的粘合。MAMMOBOT的可操纵性是通过一个亚毫米轮廓的肌腱驱动导管来实现的，该导管穿过其内腔。占空比控制器控制转向与增长，以在环人框架内的复杂环境中实现导航。台式实验评估证明了该机器人的功能以及与其动力学的降序模式（ROM）的一致性。最后，针对此项目开发的定制乳房幻像的实验评估证明了MAMMOBOT的临床相关性和潜在影响。