Session F3E PROBLEM-BASED LEARNING IN BIOMEDICAL ENGINEERING CURRICULA Michelle C. LaPlaca1, Wendy C. Newstetter2, Ajit P. Yoganathan3, Abstract Problem-based Learning (PBL) anchors learning and instruction in concrete problems. We believe that PBL is well suited to educating undergraduate and graduate students within the interdisciplinary field of biomedical engineering (BME). BME draws upon many traditional disciplines to address a range of problems, from biotechnology to clinical medicine. A challenge for BME educators is to balance this broad base of fundamentals with the analytical, in depth problem solving necessary to be successful bioengineers. The ability to adapt, be innovative, and acquire and integrate relevant information is not efficiently learned in a lecture format, but rather in a small group setting that encourages self-directed learning, such as PBL. We have developed a graduate BME program with PBL as one of the pivotal components and are embarking on the introduction of this methodology to undergraduate sections. We have found PBL to be an effective vehicle for instruction, retention of material, and introduction of topics necessary for professional development. Index Terms Biomedical Engineering, Interdisciplinary Education, Problem-based Learning
THE CHALLENGE OF BIOMEDICAL ENGINEERING EDUCATION The definition of biomedical engineering (BME) as an engineering discipline requires a careful examination of changing technology and biomedical health needs of the next century. The field of BME is the result of the merger between traditional engineering disciplines such as mechanical, chemical, and electrical engineering and the biology-based disciplines of life sciences and medicine. This merger was prompted by the need to improve procedures such as diagnostic testing, noninvasive surgical techniques, and patient rehabilitation and to apply quantitative analyses to biological problems. BME has evolved into one of the fastest growing fields and continues to have a significant impact on medicine, biotechnology, and basic science. The multidisciplinary nature of BME creates challenges on the educational front. On the one hand, BME demands that education keep abreast of advances in several facets of
science and engineering. With medical technology changing at such a rapid pace, classroom practitioners are hard pressed to keep abreast of advancements in all the related fields. On the student front, the learning challenges are immense. The multidisciplinary nature of the field demands that students develop multidisciplinary skills and knowledge. They need the modeling and quantitative skills of traditional engineers, but they also need the systems understanding representative of a more biological approach. In short, they need to be fully conversant in two intellectual traditions that are in some ways at odds with one another. Engineering seeks to analyze the world in order to set constraints and design, while the life sciences work from hypotheses towards explanatory accounts of phenomena. Reconciling these two disparate practices requires cognitive flexibility and true interdisciplinary thinking. Therefore, a cornerstone of BME educational programs is to provide students with valuable real-world experiences (clinical and research) which help them develop true interdisciplinarity. This may involve BME students working in close collaboration with clinicians, medical students, medical interns/fellows and medical researchers in both clinical and research settings. Furthermore, the advancement of BME research and manufacturing activities necessitates that in educating the much needed manpower and leadership for U.S. industry and academia, students should acquire experience in topics of modern BME industry that are currently not part of traditional academic studies. In particular, students should be exposed to product design, development and manufacturing, regulatory requirements, clinical studies and working in a multidisciplinary team environment. The best way to provide this education is through exposure to the problems encountered by biomedical companies and medical centers. In fact, companies and research laboratories are a tremendous resource for problem development for BME courses. Given the value and importance of real world problem solving in the BME curriculum, how can professors and students best be supported in undertaking such a pedagogic approach? What can we anticipate in terms of learning outcomes? What educational precedents are there in other fields which could inform our efforts in the reform of engineering education through problem-based learning?
1 Michelle C. LaPlaca, Georgia Tech / Emory Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 303325035,
[email protected] 2 Wendy Newstetter, Georgia Tech / Emory Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 303325035,
[email protected] 3 Ajit P. Yoganathan, Georgia Tech / Emory Department of Biomedical Engineering, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 303325035,
[email protected]
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Session F3E PROBLEM-BASED LEARNING Problem-based Learning (PBL) as an educational approach has been widely used in medical education for more than a decade and recently in educational settings as diverse as teacher education and undergraduate economics. It is recognized that students learn more effectively by actively participating in learning and by studying subjects indepth[1]. PBL is a learning approach designed to help students learn content and develop important reasoning skills as they solve authentic problems in their discipline. The learning and instruction are anchored in concrete problems that afford free inquiry. The classes, or teams, are comprised of five to seven students and learning is studentcentered. The instructor in PBL is a facilitator, whose primary role is to facilitate learning by asking questions and encouraging in-depth probing, rather than presenting facts or information in a didactic manner[2]. The goals of PBL are to develop students' critical thinking and reasoning skills and to help them become self-directed learners who are eventually independent of their instructors. This results in students who are capable of adaptation, creativity, and are responsible for life-long learning. PBL Methodology Problems are formulated to present a minimal amount of information about a situation (e.g. a patient's symptoms, the failure specifications of a structure)[3]. This is the problem statement, which may be issued with a short list of suggested resource persons (this list is not always given to more experienced students). When the student team first tackles the problem, they identify and articulate knowledge they already possess that is relevant to the case. In cognitive science terms, they activate their prior knowledge and preconceptions of a domain as a first foray into the problem space. This is enacted as a period of initial “brainstorming" of possible solutions which involves the generation of hypotheses. These solutions may or may not be feasible and may be eliminated as the session proceeds. The purpose is for the students to initially examine the problem qualitatively (as would an expert) and to identify inquiry material needed and learning issues to be explored (i.e. what information is missing in order to solve the problem). Some of this inquiry material can be provided to the students on an "as asked" basis if the facilitator has it (e.g. the results of a medical test, the original design of structure). Following data gathering, the students narrow down the viable hypotheses and identify the critical learning issues as a team. They research the topic on their own and consult with appropriate individuals and resources before returning to the group. The students are encouraged to take advantage of the skills and knowledge of each other. Students then report on their work, keep a log of their activities, and discuss the various solutions. The student outcome is then presented as requested by the problem definition (e.g.
diagnosis of the patient, conclusion of how a structure failed and could have been prevented). The resultant learning is often presented as a concept map, a depiction of the processes and mechanisms learned in solving the problem. The focus is on the underlying science or engineering fundamentals, rather than the "correct answer". Typical characteristics for the PBL session as we have utilized this methodology are given in Table I. TABLE I STEPS FOR PROBLEM-BASED LEARNING CLASSES USED IN GT/EMORY BME FOR A TYPICAL PROBLEM SESSION (6-8 90-MINUTE CLASS PERIODS) Component Typical Class Time Comments (Graduate Students) Facilitator guides for 10-15 minutes Problem Statement proper interpretation Facilitator allows free Brainstorm/Initial Remainder of 1st inquiry Hypotheses Development class (60 minutes) Generation of Inquiry Questions
1st and 2nd class
Questions include "why", "how"…
Generation of Learning Issues
1st and 2nd class
Facilitator actively asking probing questions
Research Learning Issues
2nd - 4th class
Student report to each other/probe each other
Revisit/Narrow Hypotheses
2nd - 5th class
Outcome/Concept Map
5th - 6th class
Assessment
7th class
Learning issues/ hypotheses iteratively revisited Students work independently/together Assess self, peers, and facilitator
During the PBL session, students should be brought to the level of knowing what they do not know but need to know to solve the problem. It is the responsibility of the facilitator to ask questions that probe the students' knowledge until they do not know the next step or process[2]. An experienced PBL team will do this in-depth probing on their own−peer to peer. Studies have shown that PBL students learn considerably more than their peers do in traditional learning environments about how to solve problems, how to manage their own learning, and how to work with others[4-6]. PBL provides methodology, to which the students return every time they face a new problem. In addition, it encourages collaborative and explanatory interactions with others. PBL in Engineering
PBL is well suited for learning in engineering but is not meant to replace project, design, and case study. PBL is a different methodology in that the students eventually become entirely responsible for their own learning and independent of the instructor. Project and design classes are important components of engineering education, particularly at the undergraduate level, but the classes typically involve 0-7803-6669-7/01/$10.00 © 2001 IEEE October 10 - 13, 2001 Reno, NV 31st ASEE/IEEE Frontiers in Education Conference F3E-17
Session F3E application of material learned in more traditional classes to a problem. It encourages creativity and independent thinking, but the instructor usually will indicate if the design is "correct", offer suggestions, and therefore serves as an "regulator" more than a "faciltitator". Case study instructors often offer new information as needed, counter students' hypotheses with alternative options, and compare and contrast the resulting solutions. The instructor provides feedback, indicating whether or not the student is right, whereas the PBL approach requires that students come to their own conclusions. The problem solving process is actual learning, not merely application of knowledge. For example, a senior design class might present a problem as: Design and optimize bi-directional interfaces between excitable cells and electrodes. A design statement such as this might be divided among several teams in a competition format and is open-ended, in that, teams would likely generate different designs. A PBL problem that was formulated to have students get to the same design stage while learning the curricular components associated with it might be stated as: You are a BME researcher for a private start-up company who had some initial success in the implantation of bi-directional electrodes in damaged neural tissue. The last three implantations have failed and the company president wants to know why. The problem stated this way encourages the students to learn curricular components (e.g. cell biology, physiology, bioelectronics, signal processing) and elements of design.
PBL AS A CORE CURRICULAR COMPONENT PBL in the Georgia Tech/Emory Graduate Program We believe that PBL is a central strength to the joint graduate program in the Georgia/Tech Emory Department of BME and core to the general philosophy of integrative and adaptive learning. This joint graduate program (joint between Georgia Tech and Emory, introduced Fall 2000) is separate from the Bioengineering Program at Georgia Tech, which has credit requirements in bioengineering, bioscience, and traditional engineering, but is less structured than the joint program. Currently the joint BME program has two credits of PBL class per semester for the first two years. The fall 2000 entering class has eight students in PBL−three from life science backgrounds and five from engineering backgrounds. Our PBL course is meant to supplement our other courses (engineering science, life science, and physiologic systems courses) and provide a "glue" for the material learned in more traditional settings. We strongly feel, however, that once established and experienced in PBL facilitation, more curricular objectives could be learned solely in PBL, with other courses acting as reinforcement or electives. Given that some medical schools provide their entire instruction in a PBL format, it is feasible that disciplines such as BME could move in this direction at the graduate level. The methods and results presented herein are
based on our experiences in the first semester of our program and may reflect the uniqueness of our components. These methods can be applied to other programs and may yield different, yet equally beneficial, outcomes. The Challenges of Problem Development A critical aspect of PBL is problem fidelity. Students will be motivated to engage with a problem if they perceive that it represents a real-world, complex challenge, not a sanitized, pared-down classroom exercise. The problems that we have utilized have been generated by professors at Georgia Tech and have been based on their areas of expertise. In most cases, the problems are real; that is, based on real research problems or problems arising when consulting for industry. Problem designers for a given semester work together to ensure that all desired curricular objectives are met. We complete a curricular matrix to verify that our problems act to integrate the material presented in other classes (see Table II). It is strongly believed that the facilitator should not be the expert in that area, to ensure that the facilitator guides the reasoning processes of the students and does not bias them in a certain direction. The facilitator and the problem designer must work closely together, however, to make certain the curricular objectives are met. TABLE II EXCERPT FROM AN EXAMPLE CURRICULAR MATRIX Curricular Component Problem 1: Problem 2: BME Company, BiMyotonic Dystrophy, a directional Electrodes Case of Heart Failure X-soft tissue Mechanics X-blood flow
Biomaterials
X-diffusion of growth factors X-electrode materials
Cell Biology
X-neurobiology
Physiology
X-neural disease
X-electric properties of heart cells X-cardiac physiology
Biochemistry/ Molecular Biology
-
X-genetic diseases
Biosignals
X-amplification issues, stimulation of tissue
X-diagnostic heart monitoring
Transport
-
We have often found that problems need to be rewritten, or retooled, because students interpret the problem goals differently from what we had intended and therefore the learning outcomes are different from those desired. When this happens, the cause can lie either in problem presentation itself or in the facilitation of the problem. In the former case, the problem may need to be reworded to focus the learning in a different direction. This might mean changing the problem goals or even removing certain problematic words. As an example, we asked our graduate students to develop a presentation for a Board of Directors as the goal of one problem. We later learned from them that this goal
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Session F3E retarded their learning because a week or so before the presentation all domain learning halted in preparation for the presentation. We had anticipated that the presentation would be a motivator, but, in fact, it prematurely stopped their inquiry into the intended learning areas. This was because their focal activity had shifted from learning to product development and presentation skills. We have since eradicated any sort of public presentation, written or oral, from the problem statements. Our experience tells us that almost without exception, we have to retool problems after they have been run for more optimal learning. Problem development is a case of iterative design. The first instantiation of the problem is a prototype that needs testing out in real world circumstances. As a first prototyping step, we have found it extremely useful to "try out" the problem on small faculty groups to see where they go with the problem. This can serve as a predictor of where we want the students to go or on the contrary, where we do not want them to go when the problem statement is misleading. Another challenge in problem development is deciding which resources to provide in the problem and which to leave out for the students to find for themselves. Such decisions revolve around what will be learned by the student in tracking down a resource. If the learning is peripheral to the content area in which the problem is anchored, it is probably best to provide the information. As an example, one problem undertaken by our students was based on a realworld case involving a patient who had died. The parents of this patient were willing to interact with students over email and phone but the time that it took to get a response from the parents regarding fairly simple questions like “Did she ever have fainting spells?” was unjustifiable. These kinds of data could easily have been provided in a casebook. Nevertheless it is important for students to encounter difficulties finding the necessary resources and to discuss how and where they obtained the resources that are brought back to the group (e.g. manuscript writing, journal quality, and fidelity of web resources). This is an important component of self-directed learning. Although the PBL component of our curriculum is evolving and the problems used thus far are in the process of being retooled for subsequent classes, we present some of our initial problems here. BME educators are very interested in developing real-world experiences for both undergraduate and graduate programs (See The Whitaker Foundation Biomedical Engineering Educational Summit, December 7-10, 2000) (summit.whitaker.org) and therefore we want to assist in catalyzing these activities. Some problems used thus far include: •
Responding to a NIH PA to design a tissue engineered heart. The problem designer wrote the PA using a model and involved NIH program directors in the student assessment.
•
•
•
Acting as a consultant to a medical examiner to analyze the mechanics of an infant during an alleged shaking episode that resulted in lethal brain damage. This was based on an actual case for which the problem designer consulted. Being a BME researcher in a company that is analyzing the failure of bi-directional electrodes. This problem was taken from the company of the problem designer's collaborator. Analyzing whether a pacemaker would have saved the life of a 17-year old girl who suffered from myotonic dystrophy and died of cardiac complications. The problem designer works in the area and knew of this actual case and had the original medical history. Facilitation of PBL
The facilitation of PBL sessions has been a challenge for those facilitators who normally teach class in a lecture format. The students often look to the facilitator as an expert (which is not the role they should assume) and we have found that this is usually the result of the type of questions coming from the facilitator. For example, if a student is presenting an idea that the facilitator knows is probably on the wrong track, the faculty member may ask "Are you sure that you have thought of all the possibilities?" From this question, it is clear that the student has missed what was desired and therefore the student will continue to look to the facilitator for the "correct" answer. Alternatively, the effective facilitator would pose the question as "Does everyone agree with this possibility?" (to bring other team members into the discussion), or "Are there any other possibilities?". It is very important to ask question the same way whether or not the student is on the right track. The facilitator guides the students to question themselves and each other without indicating the desired path. This method can be difficult at first, but when practiced this approach will yield independent thinkers. The facilitator must also ask directed questions to students who are shy or not willing to speak out. These students are usually identified early in a PBL session and it is important to encourage participation from all team members. Students must be reminded that they are not being penalized for not knowing the answer; we want them to get to this level. By probing the depths of knowledge, students learn to identify the knowledge that they need to obtain. Another function that the facilitator can serve is to help the team build bridges between the problem at hand and the content of other more traditional courses being taken at the same time. This means that the facilitator must be aware of the other material covered in the students' classes and know when to query the group about other resources that might help in solving the problem. When PBL is used as an integrating tool, content from non-PBL courses can be utilized and then anchored in the mental cases they are creating as they work towards a problem solution.
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Session F3E Student Outcomes We have had some unexpected results placing the students in realistic roles (e.g. BME consultant). Whereas these roles can provide the students with real-world experiences and much needed presentation and scientific writing experience, we found that the student got caught up in the presentation of the "right answer” and in presentation preparation. Given that the PBL sessions are 6-8 class periods, the students would stop learning by period 4-5 in order to prepare for the outcome (e.g. Power Point presentation, submission of a research proposal). We have recently changed our format to have a concept map as the outcome. In creating a concept map (either individual ones based on each team members area of "expertise" or a group map), the students see where there are "holes" in the learning, how processes fit together, and the flow of learning. Importantly, these concept maps serve as resources for the students to take with them and build problem archives for future students. They can also serve as the starting point for new problem development. By seeing what students have learned from a concept map in one problem, the developer can see what is missing and where they should aim a complimentary problem. In addition, this exercise leads to improved retention of material and more complete learning. In the future, we plan on balancing the concept map with realistic roles, but it is important to stress the learning issues and not merely the answer to a problem. In medical school PBL, for example, although the goal is to correctly diagnosis the patient, the majority of class time is spent in understanding the underlying mechanisms of the disease (i.e. the learning of curricular material) by creating concept maps. These maps translate to hypothesis driven diagnoses, rather than memorizing symptoms and disease names. Another interesting outcome of using PBL in our graduate program is being realized in the research labs. One lab director noted that the PBL student who has recently joined her lab has much better research skills than any previous student she has seen. She demonstrates the ability to undertake literature searches and find critical information with a tenacity and assurance not seen before. Both the lab director and the student cite PBL as the reason for this student’s demonstrated ability to aggressively tackle a problem rather than waiting for direction. Assessment Assessment of both self and the team is done after each problem. The students should acquire awareness that their own learning, and the learning of others in the group, is their responsibility. They assess their own contribution, as well as that of others and the facilitator, to the knowledge gained and the group product. At the end of the course, the facilitator assesses students in terms of the following expected outcomes:
• •
• • •
The ability to achieve a fundamental understanding of principles and to develop hypothesis driven methods. An ability to identify, formulate and solve scientific and technological problems by applying and integrating fundamental knowledge of mathematics, life sciences, and engineering, using modern scientific techniques, skills, and tools. An ability to design experiments and to analyze and interpret data. An ability to gain a broad understanding of the impact of technological solutions in a global, societal, environmental, and health care context. An ability to function and communicate effectively in a very multidisciplinary environment, especially with life scientists, engineers, clinicians and other health professionals. PBL Courses in Undergraduate BME Education
We are currently in the planning stages to expand existing graduate PBL courses in BME to undergraduates as a core requirement in the first year of the curriculum. Integrative, learner-centered approaches to interdisciplinary problems are central to BME education and it is postulated that early introduction to these techniques will maximize undergraduate-level learning and prepare students for lifelong adaptive learning. It is purported that the early introduction of PBL in the higher education program will allow students to learn how to actively approach interdisciplinary problems before subdiscipline segregation takes place. The primary difference between undergraduate and graduate level PBL will be in the level of expertise and the level of bias. Whereas graduate students enter the program with more engineering and/or life science experience, they have more preconceived ideas about the subdisciplines encountered. As the graduate students become more familiar with PBL as a method of learning, those interested in mentoring will have opportunity to facilitate PBL classes. As discussed above, the PBL class will be taken in addition to undergraduate design projects and labs and is not meant to replace these very valuable teaching approaches, but rather augment the students’ experiences. Each semester will comprise approximately twelve problems in a variety of areas. We want them to develop the kind of problem solving versatility that would allow them to undertake a biologybased problem on perhaps drift and diffusion one week and the following week work on a chemical engineering problem having to do with control systems. The goal of the undergraduate PBL program will be to develop the metacognitive skills that support optimal solving of illstructured complex problems.
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Session F3E SUMMARY AND CONCLUSIONS The learning that takes place in PBL is learner driven; the students identify those aspects of a problem that they don’t know and formulate hypotheses to problem solutions. Students acquire the ability to ask questions and examine a problem qualitatively prior to applying detailed analysis, skills that are important to practicing biomedical engineers. When assimilating knowledge from engineering, biology, and medicine, small group settings encourage students to learn from each other. Critical aspects of PBL include problem development and facilitation. The problems must represent real-world problems and be designed to cover curricular objectives. We have learned that retooling of problems is often necessary. Equally as important is the facilitation of the problems, a challenge to instructors used to didactic teaching styles. We have also found that guiding the students in a PBL settings has led to in-depth learning in non-curricular, but essential, areas such as grant writing, legal, insurance, and ethical issues. In addition, graduate students have begun to develop important skills in group dynamics, effective communication methods, selfassessment, and assessment of others. These skills are as essential in the professional work environment as the curricular learning issues that the problems are designed to address. We will use these experiences to develop and retool problems for undergraduate BME students.
ACKNOWLEDGMENT The authors acknowledge the graduate students in the entering class 2000 at Georgia Tech / Emory Department of Biomedical Engineering for their receptiveness to trying new learning methods and all the feedback that they continuously provide. Problem designers in the Georgia Tech / Emory Department of Biomedical Engineering include Julia Babensee, Michelle LaPlaca, Stephen DeWeerth, William Ditto, Paul Benkeser, and Joseph LeDoux.
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