Abstract

The magnetic coil was invented in the mid-19th century by Herman von Helmholtz. This coil can create a uniform magnetic field. The main structure of the coil consists of two identical coils that are in the direction of one of the three-axis X, Y or Z. Around each coil, there is a series of conductors with the same current I. The best performance of this coil is when the distance between the coils is equal to the radius of the coil.1,2 As the current flows through the wires, a magnetic field is created around the coil and a homogeneous magnetic field is formed inside the coil (Figure 1).3,4 This coil is used for medical applications such as hyperthermia and smart drug delivery. In hyperthermia for the treatment of cancer cells increased tissue temperature because they are sensitive to temperature.5 In this method, directly or through the intravenous system, the fluid containing the magnetic nanoparticles enters the target tissue, then the coil produces an alternating magnetic field.6 This magnetic field causes the nanoparticles to emit heat. When the tissue temperature reaches above 42degrees cancer cells are destroyed.7 The iron oxide nanoparticles are used for drug delivery.8 The size of magnetic particles is about 5-50nm.9 When the nanoparticles combine with an external field, they allow the particles to be delivered to the desired region.10,11 Smart drug delivery can eliminate side effects and reduce the dose of medication needed.12,13 The purpose of this article is to present a new model of coils for medical applications.

Keywords

Helmholtz, homogeneous, axis, hyperthermia, drug delivery, magnetic field flux, three-dimensional