2023 ASEE Annual Conference & Exposition

Signals and Systems for Biomedical Engineering (BME) is a required course for seniors in a biomedical engineering program at a medium-sized engineering university on the East Coast. Signals and systems is an important course for engineers to take because it lays the foundation for digital signal processing, which is at the core of most technologies nowadays. The approach of the course is to engage students with a variety of active learning interventions to illustrate the fundamental concepts and methods of signals and systems. This paper illustrates how lab activities, integrated into the lecture periods, were utilized to enhance the teaching and learning of the complex concepts covered in the course.
Inclusion of the active learning interventions described in this paper was motivated by the instructor’s experience and observations from delivering the course to eleven cohorts of students over the past five years. Signals and systems tends to be a challenging course for most engineering students, and more-so for BME students, because intuitive knowledge of calculus, differential equations, circuit analysis, and applications to human physiology are required. To absorb the material requires fluidity in shifting between mathematical and graphical representations of signals as well as switching between domains (e.g., time and frequency/ Laplace domains). Adding to the complexity, digital signal processing requires facility with modeling and simulation tools such as Matlab.

Signals and systems is usually taught from the perspective of mathematical modeling of systems, where the signals analyzed are mostly periodic and predictable. Signals and systems courses taught solely from the perspective of math lose the vital connections that students should make between theory and application . For BME students, an added challenge is that signals and systems focuses on modeling and analysis of physiological signals, which are typically not periodic and are less predictable. This presents a unique educational opportunity for BME students by learning the material by working with their own physiological signals. Students can relate the concepts and models to how their own bodies operate, such as analyzing their own vital signs including heart rate, blood pressure, and breathing rate.

The course is scheduled as three fifty-minute lectures per week. Since there is not enough time for a full-length lab, “Flash-labs” were introduced to be covered within the lecture sessions. Labs help students to learn the concepts in depth and to gain practical skills. Flash-labs are “pre-canned” for students, so they just need to execute them and report and discuss their findings with their classmates in small groups and through reflective postings in their e-portfolios, and with peer review. Flash-labs focus on biomedical applications including ECG, EEG, EMG, filtering in hearing-aids, heart-rate-variability to monitor stress levels, as well as clinical application such as blood pressure monitoring and closed-loop drug infusion control.

In this paper, results of analysis of the effectiveness and impact of flash-labs in signals and systems course are presented. Thematic analysis of student reports and reflections is currently being performed following established methods, with themes identified solely based on collected data without pre-existing code sets. Future plans include photovoice analysis of student reflections about their flash-lab experience. Preliminary observations indicate that, while some of the labs were more effective than others, overall, they served to deepen the understanding and application of the material learned in the course. One of the authors of this paper, is delivering the course in the Spring 2023 semester. Data from this offering may be incorporated if time to publication allows.