Optimal Halbach permanent magnet designs for maximally pulling and pushing nanoparticles |
| |
Authors: | A Sarwar A NemirovskiB Shapiro |
| |
Institution: | a Fischell Department of Bioengineering, College Park, MD, USA b Institute for Systems Research, USA c University of Maryland at College Park, USA d H. Milton Stewart School of Industrial and Systems Engineering (ISyE), Georgia Institute of Technology, USA |
| |
Abstract: | Optimization methods are presented to design Halbach arrays to maximize the forces applied on magnetic nanoparticles at deep tissue locations. In magnetic drug targeting, where magnets are used to focus therapeutic nanoparticles to disease locations, the sharp fall off of magnetic fields and forces with distances from magnets has limited the depth of targeting. Creating stronger forces at a depth by optimally designed Halbach arrays would allow treatment of a wider class of patients, e.g. patients with deeper tumors. The presented optimization methods are based on semi-definite quadratic programming, yield provably globally optimal Halbach designs in 2 and 3-dimensions, for maximal pull or push magnetic forces (stronger pull forces can collect nanoparticles against blood forces in deeper vessels; push forces can be used to inject particles into precise locations, e.g. into the inner ear). These Halbach designs, here tested in simulations of Maxwell's equations, significantly outperform benchmark magnets of the same size and strength. For example, a 3-dimensional 36 element 2000 cm3 volume optimal Halbach design yields a 5× greater force at a 10 cm depth compared to a uniformly magnetized magnet of the same size and strength. The designed arrays should be feasible to construct, as they have a similar strength (≤1 T), size (≤2000 cm3), and number of elements (≤36) as previously demonstrated arrays, and retain good performance for reasonable manufacturing errors (element magnetization direction errors ≤5°), thus yielding practical designs to improve magnetic drug targeting treatment depths. |
| |
Keywords: | Magnetic nanoparticle Targeted drug deliver Magnetic drug targeting Optimal permanent magnet Nano-particle trapping Pushing nanoparticle Halbach array design |
本文献已被 ScienceDirect 等数据库收录! |
|