HTS Coil and HTS Bulk Arrangement Suitable for Two-Dimensional Navigation of Magnetic Drugs for MDDS

To realize Magnetic Drug Delivery System (MDDS), it is necessary to generate a magnetic field distribution that allows localized accumulation and navigation of magnetic drugs. However, single magnetic field sources have a large magnetic force perpendicular to the blood vessel, making it difficult to achieve local accumulation and navigation of the magnetic drug. In our previous study, we proposed a magnetic field configuration method of placing two zero-field-cooled cylindrical HTS bulks inside an HTS coil to reduce the magnetic force perpendicular to the blood vessel and increase the magnetic force in the longitudinal direction of the blood vessel. However, two-dimensional accumulation is required to navigate at the bifurcation. Therefore, we investigated a magnetic field source configuration method suitable for two-dimensional local accumulation and navigation of magnetic drugs. First, we considered placing four zero-field-cooled cylindrical HTS bulks inside the HTS coil to realize two-dimensional local accumulation and navigation. The results showed that the magnetic field source configuration method suitable for accumulation and navigation in the longitudinal direction of the blood vessel can be extended to the width direction, and that the shielding current loop diameters formed inside and outside the four HTS bulks must be arbitrarily adjusted. Therefore, we varied the inner and outer diameters of a cylindrical HTS bulk with a hollow and four slits. We found that it is possible to form a magnetic field distribution suitable for two-dimensional accumulation and navigation of magnetic drugs by moderately adjusting the inner and outer diameters.