In biomedical engineering, Signals and Systems is a compulsory course. It’s split into two sections:

1. Theory (usually with a credit hour requirement of 1 hour)
2. Lab/Practicals (usually with a credit hour requirement of 2 hours)

The theory part deals with the study of how signals are produced from the human body or man-instrument systems and processed for diagnostic or research purposes.

The lab part deals with the learning of MATLAB, which is a software that enables digital signal processing. It’s a paid software, so you will either have to ask your university to provide this software or download a free (but unsafe) version on your PC.

Let’s check out this course in deeper detail…

Why are we studying this course?

The study of “signals and systems” is fundamental in biomedical engineering for several reasons:

1. Signal Processing in Medical Data

Biomedical signals, such as those from electrocardiograms (ECG), electroencephalograms (EEG), and medical imaging modalities like MRI or CT scans, are vital for diagnosing and monitoring various medical conditions.

Signal processing techniques are used to extract relevant information from these signals, filter out noise, and enhance the quality of the data.

2. Diagnostic Tools

Understanding signals and systems is crucial for developing diagnostic tools. Biomedical engineers design and analyze devices that collect and interpret physiological signals to aid in the diagnosis of diseases.

3. Biomedical Imaging

Medical imaging systems rely heavily on signal processing. Signals from different modalities, such as ultrasound, X-rays, or magnetic resonance, need to be processed and reconstructed to form meaningful images for medical diagnosis and treatment planning.

4. Feedback Control Systems

Biomedical devices often involve closed-loop control systems. For example, insulin pumps for diabetes management or pacemakers for cardiac rhythm control require a solid understanding of signals and systems for their design and operation.

5. Biological Signal Analysis

Biological systems themselves can be modeled as systems, and signals arising from these systems can be analyzed using signal processing techniques. For example, studying the electrical signals in nerve cells or the biomechanics of muscle contraction involves principles from signals and systems.

6. Drug Delivery Systems

Understanding signals and systems is essential in the development of drug delivery systems. These systems often involve the controlled release of drugs based on physiological signals or feedback from the body.

7. Rehabilitation Engineering

In designing assistive devices for individuals with disabilities, such as prosthetics or exoskeletons, signals from the human body need to be accurately sensed, processed, and used to control the devices. This requires a deep understanding of signals and systems.

8. Telemedicine and Remote Monitoring

With the increasing use of telemedicine and remote patient monitoring, biomedical engineers work on developing systems that can transmit and analyze biomedical signals in real-time, providing healthcare professionals with valuable information for decision-making.

What are Signals?

There are various ways to define a signal. Allan Oppenheimer (MIT lecturer, author of “Signals & Systems”) defines it as:

“ A signal is a function of two or more independent variables that typically carry some sort of information.”

OR in other words; a signal is a combination of one or more than one independent variable.

OR you can define as; signals carry useful information from one point to another without any noise.

All three definitions are valid and accurate.

Some examples of signals include:

• Bioacoustic signals (Sound waves generated by blood pressure)
• Biomechanical signals (skeletal/muscle movement)
• Bioelectric signals (ECG, EEG, EMG)
• Biothermal signals (signals generated from body heat)

Allan Oppenheimer gives the example of “speech signals” in his lecture. Speech signal is a one-dimensional function (air pressure) of time. The sound waves are converted into electrical signals as it goes through the transducers of a microphone.

To learn about the types of signals, types of systems, and techniques of solving signals and system questions, hop onto this post: Introduction to Signals and System

End Note

Note that this course often has a mathematical pre-req course (like Linear Algebra & Differential Equations, Calculus, etc.) So, during the course, you should expect to deal with mathematical concepts like ordinary differential equations, integration, laplace transform, etc.

It’s also worth mentioning that most of the content you’ll find on the internet concerning “Signals & Systems” — it’s relevant to electrical engineering. That’s alright from on-field practice perspective. But as a student (from paper perspective), these resources will offer lots of extra details that you do not need to study.

So, if you have a paper coming up, it’s best to stick to this site. Saves time with smart prep — as practicing biomedical engineers have compiled all our guides specific to the field. In case of specific queries, feel free to DM us on any of our socials. Our experts will get back asap!