Page 202 - Computational Modeling in Biomedical Engineering and Medical Physics

Magnetic drug targeting 191

Planar coil
Skin, tissue
Vessel walls
Magnetic fluid
(blood and MD)

Substrate, tissue

Figure 6.15 The bidimensional computational domain in the MDT controlled using a planar coil.

Table 6.2 The total force that different configurations of the magnetic field source.
Number of slots, NS 1 2 3 5

F mg;y [N] 1.0763 1.0632 1.0512 1.0093
2
Þ [daN/m ] 538.15 548.323 468.449 369.707
F mg;y = AL 3 SWð

control (of higher gradient due to its spatial spectrum rather than intensity) for NS 5 5
may supposedly help retaining and “collecting” more efficiently the MNPs.
Table 6.2 (S˘ andoiu, 2019) lists the maxima of the attraction force. Here AL is
the linear size of magnetic array in streamwise direction, computed as
AL 5 NS 3 SW 1 NS 2 1Þ 3 GS. Apparently the array of NS 5 2 blocks provides
ð
for the best magnetic extraction force.
Ð Ð
The total stream-wise force is defined as F total 5 pdS 1 F mg;z dV, where S is
S V
area of the wetted surface of the vessel, and V is the volume of the MAF. The mag-
netic term contributes to the mixing of the MAF.

Using electromagnets for magnetic drug targeting
For the magnetic fields to be used in MDT to direct inner body actions, they have
to be intense and to exhibit high gradients able to produce forces required to pre-
cisely lead the MD to the ROI, thus limiting the toxic drug spreading to unharmed
cells (Alexiou et al., 2003, 2006a,b; Li et al., 2018). To this aim current coils may be
used too. Their design and control can be tailored to meet specific needs and a com-
panion bidimensional model is useful to prove this concept (Morega et al., 2015).
First an analysis derived from the previous, PM study, is conducted to validate this
concept, Fig. 6.15.