Magnetically Actuated Microrobots for Tissue Elasticity Mapping in Colorectal Cancer Diagnosis

Colorectal cancer is a major global health issue, ranking among the leading causes of cancer-related mortality. Early detection significantly improves patient outcomes; however, current diagnostic methods such as colonoscopy and traditional imaging primarily rely on visual inspection, limiting their effectiveness in detecting early- stage lesions. Recent research highlights increased tumour stiffness due to cellular proliferation and extracellular matrix changes as a promising mechanical biomarker for early cancer detection. Magnetically actuated microrobots have recently emerged as versatile tools for medical applications. Their precise, externally controlled movements allow them to perform various tasks, including targeted drug delivery, minimally invasive surgery, and tissue characterization. This thesis investigates whether these microrobots can effectively measure colorectal tissue stiffness for early cancer diagnosis. The research combines mathematical modelling, computational simulations, and experimental validation using engineered phantom materials and ex-vivo tissue samples. A mathematical model describing microrobot-tissue interactions was developed and validated through simulations and experiments, assessing how system parameters change the dynamics of the microrobot being actuated from within a confined environment. Computational frameworks integrating computational fluid dynamics, discrete element methods, and finite element analysis were created to realistically simulate microrobot dynamics within biological environments, assessing the shear wave behaviour and being used to probe the viscoelastic properties. Additionally, experimental validation demonstrated a novel elastography approach combining magnetic microrobots with laser speckle contrast imaging, accurately quantifying variations in tissue stiffness, confirming the methods sensitivity and clinical potential. The compact, non-contact design of microrobotic systems makes them suitable for integration with existing colonoscopic platforms, providing comple- mentary quantitative diagnostic capabilities. Overall, this thesis presents effective methods using magnetically controlled microrobots to advance colorectal cancer detection through mechanical tissue characterization.<p></p>

Author dc:creator

• Andrew Bickerdike (21060392)

• Microrobots
• Engineering

Statement dc:rights

• All rights reserved
• Open Access after 2027-05-18

Identifier

10779/exe.32324553.v1

OAI identifier oai:identifier

oai:figshare.com:article/32324553