Cardiovascular diseases, such as ischemic stroke and myocardial infarction, are leading global causes of mortality driven by thrombotic occlusions. Current clinical approaches for removing blood clots are highly effective in large vessels but lack the accessibility and precision required for challenging, small-vessel regions. Untethered Magnetic Robots (UMRs) and the Wireless Clot Remover (WCR) concept offer a promising approach by combining magnetic actuation with mechanical structures for targeted, minimally invasive interventions. While existing research focuses on barbed interaction geometries, alternative mechanical strategies - such as drilling, fragmentation, and capture - remain largely unexplored. Conducted in collaboration with the Radboud University Medical Centre, this project aims to systematically develop novel mechanical geometries to optimise blood clot removal.
Current wireless clot removal systems rely on a narrow scope of mechanical interaction principles, leading to suboptimal performance across varying clot types and physiological environments. Critical tradeoffs between extraction effectiveness, vessel wall safety, manufacturability, and magnetic actuation compatibility have yet to be systematically quantified.
The central problem is therefore defined as: The identification and development of a mechanical interaction strategy and corresponding UMR/WCR geometry that enables effective and safe clot removal, while remaining feasible for fabrication and controlled experimental validation.
The design process of novel mechanical geometries for wireless blood clot removal using UMR/WCR systems will be strictly guided by the following five core requirements:
-Navigability: Geometries must accommodate the restrictive dimensions of the vasculature from the insertion point to the target, limiting the total length and width of the UMR/WCR assembly to navigate tight corners.
-Mobility: The system must overcome relevant physiological peristaltic flows. Designs must minimise drag and weight and ideally provide thrust or stability during rotation.
-Clot Engagement: Mechanical structures must minimise the rotational or longitudinal forces required for initial penetration while maximising the pulling forces to prevent disengagement during extraction.
-Manufacturability: All prototypes must be viable using current in-house manufacturing capabilities, adhering to reasonable timeframes and production costs.
-Safety: Designs must mitigate the risk of vessel wall damage or unwanted entanglement.
To achieve this, the project involves the following tasks:
1. Definition of functional requirements and constraints, including performance metrics, safety considerations, and experimental feasibility.
2. Evaluation and selection of a mechanical interaction strategy (e.g., puncture, drilling, fragmentation, or capture) based on the requirements.
3. Design and development of multiple geometry concepts, informed by prior experimental insights and relevant modelling approaches.
4. Fabrication and assembly of selected designs using suitable manufacturing techniques.
5. Development and execution of experimental protocols (in vitro and ex vivo) to characterise performance.
