In Vitro Design Investigation of a Rotating Helical Magnetic Swimmer for Combined 3-D Navigation and Blood Clot Removal

This article presents a miniature magnetic swimmer and a control apparatus able to perform both 3-D path following and blood clot removal. The robots are 2.5 mm in diameter, 6 mm in length, contain an internal permanent magnet, and have cutting tips coated in diamond powder. The robots are magnetically propelled by an external magnetic system using three coil pairs arranged orthogonally. A range of robot tip designs were tested for abrading human blood clots in vitro . The best design removed a blood clot at a maximum rate of 20.13 mm^3/min. A controller for 3-D navigation is presented and tested. The best prototype was used in an experiment that combined both 3-D path following and blood clot removal.