Wireless millirobots have achieved a groundbreaking feat by navigating through a narrow blood vessel in both directions, against and along the arterial flow.
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Scientists from the University of Twente and Radboudumc deployed screw-shaped robots into a detached aorta with kidneys, manipulating them through a robotically controlled rotating magnet.
Recognizing the potential, Health Holland recently granted funds for further advancements in the technology, specifically aiming to enhance its capability to remove blood clots.
Globally, one in four individuals succumbs to conditions stemming from blood clots annually. These clots obstruct blood vessels, impeding the delivery of oxygen to specific parts of the body.
While surgeons typically employ flexible instruments to extract blood clots and restore blood flow, some anatomical regions pose challenges to accessibility. Millirobots, however, present a promising solution by overcoming these limitations and effectively eliminating blood clots from hard-to-reach blood vessels.
Synergistic Triumph
The researchers demonstrated the millirobots’ capability to navigate within blood vessels. However, to achieve this, the millirobots require power for both upstream and downstream travel, as well as precise control and localization.
Additionally, it is crucial for them to be biocompatible, ensuring that they cause no additional harm to the interior of blood vessels. The experiment, conducted at the Technical Medical Centre of the University of Twente, utilized a genuine aorta and kidneys to assess these essential factors.
This required an interdisciplinary approach and the collaboration of many different departments. The Robotics Lab, Laboratory of biointerface, blood lab, DesignLab, LipoCoat, and MESA+ all helped us achieve this successful outcome.
Islam Khalil, Researcher, University of Twente
Guided by Precision
In the experiment, the researchers employed a wireless control system using a robotically controlled rotating magnetic field to manage the millirobots. Utilizing an X-Ray machine, they successfully pinpointed the millirobot's location while guiding it through the aorta.
To simulate realistic conditions, the researchers maintained a consistent arterial flow of 120 ml per minute within the aorta.
By applying a stronger magnetic field, the millirobots are anticipated to navigate through even higher blood flows. Notably, the millirobots exhibited stable and straight trajectories both with and against the flow, even when multiple robots were operating simultaneously.
Miniature Marvels
The robots are fabricated through 3D printing, taking the form of screw-shaped objects that house a small permanent magnet within.
This tiny magnet of just one millimeter long and one millimeter in diameter is placed in such a way that it can rotate the ‘screw’ in both ways. This allows for swimming against the flow and then turning around and swimming back.
Islam Khalil, Researcher, University of Twente
The compact size enables the simultaneous use of multiple robots, and the screw-shaped design allows for effective penetration through blood clots.
Unlocking Potential
“These millirobots have huge potential in vascular surgery. Currently, we use blood thinners and flexible tools, but a millirobot can travel to hard-to-reach arteries while they only need minimal incisions to be inserted,” stated Michiel Warle, a Vascular Surgeon at Radboudumc.
In an innovative partnership involving Radboudumc and Triticum Medical (Israel), the researchers are set to enhance the millirobots, allowing them to remotely eliminate blood clots.
The consortium will explore opportunities to leverage this technology, promoting collaborative advancements in medical robotics and technical medicine. Beyond its primary application of disrupting blood clots to restore arterial blood flow, the technology holds potential for various other targeted medical interventions.
The robots can deliver drugs to very specific places in the body where the drug is needed the most. That way we have minimal side effects in the rest of the body.
Islam Khalil, Researcher, University of Twente
Power in Collaboration
This collaborative research initiative involves both Radboudumc and the University of Twente and has been financially supported by the TURBO (Twente University Radboudumc Opportunities) program.
Through the TURBO program, research groups from both institutions can transform innovative ideas into substantial research projects. To advance their work, the researchers expanded their collaboration with Triticum Medical (Israel) to further develop the millirobots.
Additional support came from Health Holland, which recently granted them a TKI-LSH (Topconsortia for Knowledge & Innovation – Life Science & Health) award for public-private partnerships.