Page 163 - Bio Engineering Approaches to Cancer Diagnosis and Treatment

7.3 Governing equations 161

electromagnetics theory has played a fundamental role in the development of bio-
medical technology. These studies include evaluation of health hazards of microwave
field emission with biological tissues and living systems, and also the therapeutic,
diagnostic, and imaging applications of electromagnetics.
Some examples of electromagnetic nanoparticles that are widely used in medi-
cine are:

• Promote hyperthermia therapy in cancer treatment
• Improved imaging quality based on magnetic resonance
• Separate cells and macromolecules and purifies cells
• Application in biomass sensors
• Help with the transfer of the desired composition including gene, drug, stem
cell, protein, and antibody to the targeted tissue
• Help with detecting particles in the in vivo and in vitro conditions using
magnetic resonance imaging (MRI)
In the following section the application of electromagnetic nanoparticles is
presented.
Magnetic separation: One of the MNPs application is to separate the desired
material/nanoparticles cells in the bio solution by utilizing a magnetic field and then
to count their numbers. Initially the magnetic field identifies and removes the labeled
MNPs from the main solution. Then the number of cells is calculated by measuring
the magnetic properties of the separated material [5].
Improved imaging quality based on magnetic resonance: MRI is one of the
relatively new methods for medical imaging. Some of the MRI advantages are its
high contrast in soft tissue, proper resolution and high penetration depth for nonin-
vasive clinical diagnosis. The main goal of the MRI is to increase the efficiency of
the imaging technique, to enhance the contrast and thus to distinguish healthy tissues
from the rest. For example, in order to enhance the contrast of the tissue images, a
MNPs based on iron oxide that is nontoxin is injected into the tissue before using
the MRI [5].

7.3 Governing equations
The governing equations related to electromagnetism are: The Gaussian equations
for electric and magnetic fields, Faraday’s law, Maxwell-Ampere equation, and the
electric charge conservation and are as follows, respectively [15].
Gauss equation for electric field:
ρ
∇ ⋅ E = (7.2)
ε 0 ∇⋅E=ρε 0
Gauss equation for magnetic field:
∇⋅= 0 (7.3) ∇⋅B=0
B