In contrast to permanent magnets, which always have a magnetic field, electromagnets only create a magnetic field when electricity runs through them. They are made from coiled wire, often wrapped around a core of ferromagnetic material, such as iron, or a coil with a hollow core (i.e., air core). The coil is connected to a power source, which gives the ability to create the magnetic field, power it down, and manipulate it in precise ways. This has opened the door to advanced medical imaging, instrumentation, and therapy applications.
But to provide these advanced capabilities, the electromagnets need to meet quality standards, such as ISO 13485, and other patient safety requirements. Here, we’ll look at some popular applications of medical electromagnets for diagnostics, therapies, and other tasks.
Diagnostic Equipment (Imaging & Scanning)
Electromagnets are widely used in diagnostic imaging and scanning systems such as MRIs and MPIs.
MRI Machines
MRI machines use superconducting solenoid electromagnet coil systems and smaller gradient coils that align hydrogen protons in a patient’s body. Radiofrequency (RF) coils work alongside these systems to transmit and receive signals. Together, they can generate responsive signals in a patient’s body and detect those signals, which machinery then translates into images.
Magnetic Particle Imaging (MPI)
This developing technology uses multiple electromagnets. A patient is given an injection of iron-oxide tracer nanoparticles, and the electromagnetic coils excite the particles, forcing them to emit signals that sensors can detect and transmit.
MPIs directly create incredibly detailed images that diagnosticians can use to examine their patients.
Other Diagnostic Uses
Other advanced imaging systems include MR spectroscopy for analyzing chemicals in tissue and Xenon MRI for advanced lung imaging.
Therapeutic Technologies
Electromagnetics are used in many advanced therapy and treatment protocols.
Radiation Therapy (Linear Accelerators)
Modern radiotherapy systems use advanced electromagnets to direct and focus particle beams at tumors. They use linear accelerators with custom-wound solenoids or C-core electromagnets for high-precision results.
Targeted Drug Delivery
Researchers have developed methods for harnessing magnetic nanoparticles (MNPs) to deliver doses of medicine within the bloodstream. High-precision electromagnets are used first to direct the nanoparticles to exactly the right site, such as a tumor, and then to trigger the release of the medication. This process delivers high-concentration pharmaceuticals with minimal impact on nearby tissue.
Magnetic Hyperthermia
With this emergency cancer treatment, magnetic nanoparticles are sent to a tumor using electromagnetically powered direction. Then a separate electromagnetic field causes the particles to heat up to around 45° C, killing cancer cells without destroying healthy tissue.
Neuromodulation (Transcranial Magnetic Stimulation (TMS)
In TMS, high-precision electromagnets placed on the patient’s scalp activate to produce short magnetic pulses that stimulate the brain. This non-invasive procedure can help with depression and other neurological conditions.
Surgical and Procedural Tools
Many innovative medical tools and instruments use specialty coil electromagnets. These help with precision guidance and control during surgery and other procedures.
- Magnetic Surgical Robots and Devices. Magnetically actuated robotics are controlled with external magnetic fields to assist with surgery.
- Magnetically Steerable Catheters and Guidewires. Catheters or guidewires with a magnetic tip can be directed by an electromagnetic field, allowing for safe, fast, and highly controlled movement for stroke interventions and cardiovascular treatments.
- Other Magnetic Tools. Other applications for electromagnets include magnetic anchors that hold surgical tools in place, steering mechanisms for wireless endoscopes, and locking retractors.
Research Frontiers in Electromagnetics & Medicine
Scientists and researchers continue to explore new applications for electromagnetics in advanced medical settings. Consider these future possibilities:
- Advanced Imaging (MPI and Beyond). MPI machines directly produce real-time images, replacing X-rays and allowing for incredibly detailed images. These machines will continue to improve over time.
- Xenon MRI. Xenon MRI systems interact with hyperpolarized xenon gas to produce alveolar-level images and create more diagnostically helpful insights.
- Magnetic Micro/Nanorobots. Robots are getting smaller, and developers are working on making microscale robots for in-body drug delivery, microsurgery, blockage removal, and other minimally invasive procedures.
- Theranostics (Combined Therapy+Diagnostics). Theranostic nanoparticles can be used as contrast agents in MRI and MPI scanning or to provide hyperthermia or drug delivery treatments.
- Magnetogenetics and Neuromodulation. Magnetic fields may be able to one day control and correct cellular activity deep within tissue, even in the brain. They may also provide wireless magnetic power for medical implants.
Looking Ahead: The Future of Electromagnets in Medicine
Electromagnets can drive increasingly advanced medical interventions and therapies, and function as powerful diagnostic tools. As coil designs evolve, the potential for new applications will continue to grow across virtually all fields of medicine.
At Custom Coils, we’re committed to driving the science of electromagnetics and coils forward to unlock greater medical advancements. We provide high-quality electromagnets for state-of-the-art medical applications and have decades of experience developing RF coils, inductors, solenoids, and more.
Contact us today to learn about partnering with us on custom-engineered electromagnet solutions, or request a quote to start your project.
