Creating New Labs for an Existing Required Biomedical Engineering Imaging Course

In an effort to increase hands on learning in the biomedical engineering curriculum, laboratory components have been added to many core courses at XXXX University. One such course is BME XXX: Modern Diagnostic Imaging Systems. Taught for (junior and/or senior) students, this course has an enrollment of 70-80 students each year. The learning objectives of the laboratory modules were to 1) give students a sense of how the equipment works in a real life setting; 2) incorporate elements of creativity and design; 3) improve student performance; 4) increase student interest in the subject material; and 5) give the students the opportunity to learn tangible skills that are applicable in the industry. Throughout the course of the semester, the students experienced a combination of design challenges, lab experiences, and clinical experiences based on the section of the course they were completing. The course had 6 sections, 5 of which had laboratories/experiences associated with them. For the first experience, students developed and printed a 3D imaging phantom to use in all subsequent imaging modalities. This required students to familiarize themselves with Fusion360 and the 3D printers, which satisfied both learning objectives 1 and 5. During the Xray section of the course, the students brought their phantoms to a research imaging facility where they were able to create Xray images and CT images of their phantoms. For the CT portion of the course, students used visible light and simple backprojection to reconstruct a wooden block. For the ultrasound unit, students arrived in the lab to their phantoms obscured by milk and had to use the ultrasound images to identify which phantom was which. For the MRI unit, students traveled to a clinically operating 3T magnet at XXXX hospital and watched while their phantoms were scanned. As an extra credit assignment, students were asked to identify which phantoms had been scanned. The same final exam was administered at the end of the course during semesters with and without the laboratory component. Note that the lecture content of the courses did not change. For the spring 2016 class with no laboratory component, the final exam score was 78.1+/11.8 (mean +/stdev). For the spring 2017 class, the final exam score was 84.6+/-8.3 (mean +/stdev). Using a t-test, there was a statistically significant difference found (P<.003). Incorporating these hand-on design and image evaluation activities into the class significantly improved student mastery of the course content. As described, the laboratory modules also met the other learning outcomes for the laboratory. Overview of Prior Modern Diagnostic Imaging Course BME XXX: Modern Diagnostic Imaging has been taught at XXXX University for over 20 years. Seven years ago, this course became one of four area core courses (called “cores”) for the BME major, typically taken during junior spring. Junior students majoring in BME are required to select two of the four area cores that are only offered in the spring. Prior to this curriculum change, the course was largely comprised of graduate students and considered an elective for undergraduates. BME XXX was largely a theoretical course that covered the imaging physics of most of the major imaging modalities currently on the market: Xray, CT, Single Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET), ultrasound, and MRI. Each topic was given roughly two weeks or four lectures to explain the imaging physics behind the modality and each topic had a separate homework assignment to allow the students to demonstrate mastery of the material. The main complaints about the course over the years was that it was too theoretical. Specifically, students complained that they weren’t able to see the equipment they were learning about or try out the imaging modalities for themselves. In addition, other faculty had expressed dismay that the course did not have laboratory modules, and thus the course was viewed as being “easy” in comparison to the other four cores, two of which have extensive wet labs. Below are some examples of feedback from students from the lecture-only course: • “It was an alright class but the tests had not much to do with the material and just the equations in the course which I think could have been changed.” • “The actual content of the class is extremely interesting. However the material isn't particularly taught well and since it's a lecture only with no recitation or lab there's no other way to learn the material or reinforce what you learn.” • “The course had excellent material, but it would have been cool to see the technology in real life.” In summary, the feedback was that the course material was dense, complex, and hard to understand. The common theme from reading our evaluations was that the course was too theoretical and was missing the hands on component that a laboratory experience would bring. Motivation for the Addition of Laboratory Modules Experiential learning through laboratory work has long been shown to be key to student retention and connection of information. To enhance student learning, many esteemed educators have recommended connecting the material being taught to an “experience”. These experiences allow them to uncover conceptual deficiencies in their own thinking and overall lead to a deeper understanding of the course content. Laboratory modules are the connection between the theory of the science and the practice of it. Our goal for this class is to give students an understanding of the imaging physics behind the 6 imaging modalities that are covered in class by incorporating experiences that allow the students to interact with the imaging modalities being taught. We believe incorporating this element is crucially important for their retention of information. The learning pyramid shows that incorporating hands on/practiced based activities significantly improves retention of the material. When students use the imaging tools themselves they get a deeper understanding of how it works and are more able to connect the information they learn in lecture to the actual device they experience in the laboratories. Adding a series of laboratory modules was seen as a way to integrate the material and form a more resilient conceptual framework from which to understand all of the imaging modalities students would encounter in the course. In addition, there was significant discussion by the departmental faculty of incorporating tangible skills into classes, requiring courses to build on one another, and incorporating design throughout the curriculum. With the curriculum adjustment, a much larger percentage of the class was undergraduates, and the class size increased precipitously, which both reduced the one-on-one time possible with each student and changed the overall level of student interest in the topic. Prior to spring of 2011, the course was less than 20 students comprised almost exclusively of Ph.D. students who were studying medical imaging systems. With the curriculum change, the course had to accommodate double the number of students that had less overall knowledge and interest in the material. Development of the Laboratory Modules The five learning objectives of the lab experiences were: 1) Give students a sense of how the equipment works in a real life setting. 2) Incorporate elements of creativity and design. 3) Improve student performance. 4) Increase student interest in the subject material. 5) Give the students the opportunity to learn tangible skills that are applicable in the industry. The course was enhanced with laboratories for the 2016-2017 academic year. Forty-seven students enrolled in BME XXX for spring 2017. In anticipation of adding laboratories to BME XXX, the BME department used laboratory funds to purchase five ultrasound scanners from Interson. Labs occurred approximately once a month with the exception of the CT module which had a lab two times a month. The deliverables were different for each laboratory and are detailed below. Lab 1: The first laboratory project was to develop and 3D print an imaging phantom that met certain specifications. Each student made a 3D model of a cup, which was the base of the phantom. The students added features to the bottom of the cup that were to test the resolution of the various imaging systems in the x, y, and z direction. The students were responsible for both creating their 3D phantom in the 3D modeling software of their choice and printing it. In addition, the students had to include their highest and lowest resolution tested in the x, y, and z directions. With this design, the students could use inherent contrast in the imaging phantom in all subsequent imaging modalities in the class. As described below, the phantoms were tested in four imaging modalities; This comprises Labs 2, 4, and 5. A photo of one of the resolution phantoms is seen in Figure 1. Figure 1: Example 3D printed Resolution Phantom Lab 1 addresses learning objectives 1, 2, and 5 by having students use 3D modeling CAD software such as Fusion 360, SolidWorks and Inventor. In addition, building a resolution phantom allowed them to apply their knowledge of point spread functions and concepts from lecture into their actual design, addressing learning objective 4. Students then were allowed to vote on their favorite resolution phantoms in class with 5 specific categories: Widest range of resolution; Most creative; Finest resolution; Best overall test of resolution; And best overall design. The 5 selected phantoms were then used in the ultrasound laboratory and the top student selected phantom was scanned with Xray, CT, and MRI. Lab 2: In this lab, students scanned the class’ favorite phantoms in the MicroCT laboratory affiliated with XXXX University, resulting in both an Xray and CT image of their chosen phantoms. The phantoms were taken to a MicroCT laboratory and scanned and the students visited the laboratory wh