2026 ASEE Annual Conference & Exposition

[SHARE] Fourier analysis is a key concept in biomedical signal processing, but it’s often introduced as a purely mathematical topic, which can limit student engagement and conceptual understanding. “Fourier Detectives” offers a hands-on way to explore spectral analysis before introducing the math. In this activity, students use commonly available mobile apps and visualization tools to investigate WiFi spectra, sound recordings, and human vital signs such as those generated by lie-detector tests (polygraphs). Students are guided to discover how complex, real-world signals can be broken down into their frequency components, making abstract concepts of time and frequency domain transformations tangible and relatable.

Implemented in a signals and systems course for biomedical engineering students, the activity illustrates how frequency analysis applies to the design and operation of wearable sensors, diagnostic devices, and physiological monitoring systems. Acting as “Fourier detectives,” students identify hidden patterns in different signals and make connections between what they see in the time and frequency domains. The activity ends with discussion and reflection, which tie together the shared analytical foundations behind wireless communication, sound, and physiological measurements, before any mathematical concepts are introduced.

The goals of this approach are to increase engagement, improve conceptual understanding, and strengthen students’ ability to interpret frequency-domain information and primes them for subsequent exposure to the math behind Fourier analysis. The paper outlines the activity design, implementation process, student feedback, and practical recommendations for adapting this approach in other courses that focus on Fourier analysis.