In vitro validation of clearing clogged vessels using microrobots

We achieve mechanical grinding of blood clots using helical microrobots with average diameter of 300 μm inside catheter segments. The helical microrobot is steered and propelled under the influence of rotating magnetic fields (20 mT). These fields are generated using a magnetic-based robotic system with two rotating dipole fields. First, we analyze the optimal configuration of the rotating dipole fields with respect to the helical microrobot to maximize the efficiency of the grinding. This analysis is done using gelatin thrombus model. Not only do we find that an offset (distance between the rotating dipole fields and the dipole of the microrobot) of 15 mm exerts an additional magnetic force to assist the grinding, but we also observe that the drilling time through the thrombus model is decreased by 39%. Second, we prepare blood clots and develop an image processing algorithm to calculate the size of the blood clot during drilling. The drilling decreases the size (disk shaped clots with diameter and length of 3 mm and 5 mm, respectively) of the blood clot by approximately 50% in 36 minutes. The demonstrated in vitro grinding experiments using helical microrobots provide broad possibilities in targeted therapy and biomedical applications.

[1]  J. Rumsfeld,et al.  Relation between hospital primary angioplasty volume and mortality for patients with acute MI treated with primary angioplasty vs thrombolytic therapy. , 2000, JAMA.

[2]  D. Mozaffarian,et al.  Heart disease and stroke statistics--2010 update: a report from the American Heart Association. , 2010, Circulation.

[3]  Islam S. M. Khalil,et al.  Magnetic-based motion control of a helical robot using two synchronized rotating dipole fields , 2014, 5th IEEE RAS/EMBS International Conference on Biomedical Robotics and Biomechatronics.

[4]  R. Zahn,et al.  The volume of primary angioplasty procedures and survival after acute myocardial infarction. , 2000, The New England journal of medicine.

[5]  W. Rogers,et al.  The volume of primary angioplasty procedures and survival after acute myocardial infarction. National Registry of Myocardial Infarction 2 Investigators. , 2000, The New England journal of medicine.

[6]  Islam S. M. Khalil,et al.  Magnetic-based closed-loop control of paramagnetic microparticles using ultrasound feedback , 2014, 2014 IEEE International Conference on Robotics and Automation (ICRA).

[7]  Li Zhang,et al.  Bio-inspired magnetic swimming microrobots for biomedical applications. , 2013, Nanoscale.

[8]  Frans Van de Werf,et al.  An international randomized trial comparing four thrombolytic strategies for acute myocardial infarction. , 1993, The New England journal of medicine.

[9]  Jake J. Abbott,et al.  Managing magnetic force applied to a magnetic device by a rotating dipole field , 2011 .

[10]  Jake J. Abbott,et al.  Wireless control of magnetic helical microrobots using a rotating-permanent-magnet manipulator , 2010, 2010 IEEE International Conference on Robotics and Automation.

[11]  Jake J. Abbott,et al.  An empirical study of the role of magnetic, geometric, and tissue properties on the turning radius of magnetically driven screws , 2013, 2013 IEEE International Conference on Robotics and Automation.

[12]  Yu-Hao Lin,et al.  Controlled manipulation of Fe₃O₄ nanoparticles in an oscillating magnetic field for fast ablation of microchannel occlusion. , 2015, Nanoscale.

[13]  Soichiro Tottori,et al.  Magnetic helical micromachines. , 2013, Chemistry.

[14]  Brahm Goldstein,et al.  Effects of inhaled nitric oxide on hemostasis in healthy adults treated with heparin: a randomized, controlled, blinded crossover study , 2012, Thrombosis Journal.

[15]  Ioannis K. Kaliakatsos,et al.  Microrobots for minimally invasive medicine. , 2010, Annual review of biomedical engineering.

[16]  Bradley J. Nelson,et al.  Flagella-like Propulsion for Microrobots Using a Nanocoil and a Rotating Electromagnetic Field , 2007, Proceedings 2007 IEEE International Conference on Robotics and Automation.

[17]  Jake J. Abbott,et al.  Generating two independent rotating magnetic fields with a single magnetic dipole for the propulsion of untethered magnetic devices , 2015, 2015 IEEE International Conference on Robotics and Automation (ICRA).

[18]  Jake J. Abbott,et al.  Control of untethered magnetically actuated tools using a rotating permanent magnet in any position , 2012, 2012 IEEE International Conference on Robotics and Automation.

[19]  Jake J. Abbott,et al.  How Should Microrobots Swim? , 2009, ISRR.

[20]  John G. Gibbs,et al.  Nanopropellers and their actuation in complex viscoelastic media. , 2014, ACS nano.

[21]  Islam S. M. Khalil,et al.  Propulsion and steering of helical magnetic microrobots using two synchronized rotating dipole fields in three-dimensional space , 2015, 2015 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[22]  Jake J. Abbott,et al.  OctoMag: An Electromagnetic System for 5-DOF Wireless Micromanipulation , 2010, IEEE Transactions on Robotics.

[23]  Jake J. Abbott,et al.  Non-ideal behaviors of magnetically driven screws in soft tissue , 2012, 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[24]  Eric J. Topol,et al.  Illusion of Reperfusion Does Anyone Achieve Optimal Reperfusion During Acute Myocardial Infarction? , 1993, Circulation.

[25]  E. Purcell.  Life at Low Reynolds Number , 2008 .

[26]  Wei Gao,et al.  Nano/Microscale motors: biomedical opportunities and challenges. , 2012, ACS nano.

[27]  Krzysztof K. Krawczyk,et al.  Magnetic Helical Micromachines: Fabrication, Controlled Swimming, and Cargo Transport , 2012, Advanced materials.

[28]  F. Qiu,et al.  Controlled In Vivo Swimming of a Swarm of Bacteria‐Like Microrobotic Flagella , 2015, Advanced materials.

[29]  Andrew Hoffmann,et al.  Diastolic timed Vibro-Percussion at 50 Hz delivered across a chest wall sized meat barrier enhances clot dissolution and remotely administered Streptokinase effectiveness in an in-vitro model of acute coronary thrombosis , 2012, Thrombosis Journal.