Electrical engineering is developing in various fields such as signal processing, communication, circuit design, and semiconductor development, not just power. In particular, electrical engineering technology has been applied to medical devices such as MRI, enabling more precise and faster image processing, and is expected to play an important role in artificial intelligence and information processing in the future.
What do you think the Department of Electrical Engineering studies when you hear the word ‘electrical engineering’? When people hear the word ‘electricity’, they usually think of static electricity, which can be felt on a cold, dry winter day. They may also think of the electricity that powers the lights that allow people to move around in a well-lit space on a dark night, or the appliances that make their lives easier. These are all examples of electricity that we see all around us and that are essential to modern society. However, people often don’t realize what can be done when electricity and engineering meet.
Long ago, we were known as the Department of Electrical Engineering, but more recently we’ve been renamed the Department of Electrical and Computer Engineering. What does electricity and information have to do with each other? There are many reasons for the name change, but I’d like to explain what I think it is and what we do in Electrical Engineering.
In electrical engineering, “electricity” can be broadly categorized into energy and signaling. I’m interested in the latter, which deals with electricity as a signal, and this technology has advanced to the point where it has a huge impact on other industries. To explain the first one, it’s easy to understand that energy is the power source that makes something move.
Electricity, as we know it, is produced in power plants, transmitted across the country, and used to run many devices. So people who study electrical energy study how to produce electricity efficiently, how to store this energy source in batteries, and how to transmit it cheaply and with less loss.
Electrical energy is more organized than other energy sources, such as heat energy, so it loses less when transmitted over long distances, and it’s easier to convert to other forms of energy. As such, electrical energy is well suited to handle the vast amounts of energy that humanity uses, making it unthinkable to imagine life without electricity in the modern world, all to the credit of power engineers.
Now let’s talk about electricity as signaling, which is a broader concept than electricity as power. First, let’s look at the definition of a signal: In electrical engineering, a signal is a physical quantity that carries information. Specifically, it is a voltage that carries information, such as temperature, velocity, sound, pressure, among other physical quantities. There is the field of signal processing, which deals with efficiently taking in signals and processing them in a way that we can understand, and there is the field of communications, which deals with devices like radios and telephones that send and receive these signals. It’s literally a discipline that deals with signals themselves.
We need more sophisticated technology to make it easier for us to use these technologies anytime, anywhere. There is the field of circuits, which creates circuits that amplify and store signals that are sent to distant places and reduced in size through communication, and the field of semiconductors, which creates the semiconductor devices that make up those circuits. There is also the field of electrophysics and devices, which creates devices that can convert the processed signals to screens. Finally, there is the field of systems, which enables the systems of these devices to work reliably, and the field of computers, which processes the information contained in the signals. So electricity as a signal is not just a voltage, but valuable information that needs to be handled with great sensitivity.
In recent years, the field of electrical engineering has been expanding, and it would take a lot of space just to introduce the details. In this article, we’ll focus on electrical engineering as it applies to MRI, which is a collection of electrical engineering technologies. At its core, MRI requires a powerful electromagnet. You probably remember building an electromagnet in elementary school science class and seeing the pattern it drew when placed near iron powder. The electromagnet built into an MRI is much more powerful than that, which is why you can’t bring in metal objects during an MRI exam.
These powerful electromagnets align the water molecules in your body in the direction of the electromagnet’s magnetic field. In fact, more than 90% of all forces in the universe are electromagnetic, even though we don’t feel them much. Normally, electromagnetic forces are in equilibrium, so we don’t feel them, but when this equilibrium is disrupted, phenomena like static electricity and lightning occur. Going back to the MRI, when the water molecules in equilibrium receive electromagnetic waves of a certain frequency, they begin to vibrate. This is similar to the resonance effect that creates a certain sound when you pluck a string on a musical instrument, which is why MRI is called “magnetic resonance imaging”.
When stimulated, water molecules vibrate and emit electromagnetic waves of a specific frequency, the intensity of which depends on the density of water in the tissues of the body. This principle allows a receiver to pick up the signal and estimate the shape of the tissue inside the body, which is then converted into an image that a doctor can read. In the early days of MRI, it was time-consuming to acquire the signal, causing patients to feel claustrophobic.
Initially, electrical engineers specializing in signal processing worked on MRI to reduce patient discomfort and allow more patients to be imaged quickly. The result is images that are indistinguishable from the original image with much less signal than before. More recently, MRI technology has advanced to the point where we can see the heart’s movements in real time, which is a dramatic way to process biometric information.
In addition to electronics, which are already deeply embedded in our lives, electrical engineering also touches healthcare, 3D imaging, information processing, and even artificial intelligence. In the future, electrical engineering will evolve beyond simple signal processing to enable computers to process signals more intelligently.
