Feel Better Faster: All about Flow Rate

This "legacy cycle" unit is structured with a contextually-based Challenge Question followed by a sequence of instruction in which students first offer initial predictions (Generate Ideas) and then gather information from multiple sources (Multiple Perspectives). This is followed by Research and Revise, as students integrate and extend their knowledge through a variety of learning activities. The cycle concludes with formative (Test Your Mettle) and summative (Go Public) assessments that lead students towards answering the Challenge Question. See the Teacher Outline and Schedule (PDF)for the progression of the legacy cycle through the unit. Research and ideas behind this way of learning may be found in How People Learn, (Bransford, Brown & Cocking, National Academy Press, 2000); see the entire text at http://www.nap.edu/catalog.php?record_id=9853.

The "legacy cycle" is similar to the "engineering design process" in that they both involve identifying an existing societal need, combining science and math to develop solutions, and using the research conclusions to design a clear, conceived solution to the original challenge. Though the engineering design process and the legacy cycle depend on correct and accurate solutions, each focuses particularly on how the solution is devised and presented. See an overview of the steps of the engineering design process at http://www.nasa.gov/audience/foreducators/plantgrowth/reference/Eng_Design_5-12.html.

In lesson 1, students work through the Multiple Perspectives stage by developing, as a class, a list of information they need to acquire in order to answer the Challenge Question. During the Revise and Research phase, they are given scientific information about what occurs on the cellular level when a person is given antibiotics. During a teacher demonstration in an associated activity, students make observations as they observe different types of pills being dissolved, helping them to evaluate which chemical delivery method works the quickest.

In lesson 2, students continue in the Revise and Research stage to develop an understanding of how microfluidic devices are used, specifically in biological cell research. Once they have learned how to determine flow rate, students create their own microfluidic devices and test various flow rates. At the end, students complete the Go Public stage by determining that to reduce the time for medicine to get through a person's blood stream, a person should take the medicine by injection and increase his/her heart rate.

As the study of medicine moves into more macro- and micro-observations, viewing such occurrences taking place in the body, in real time, is almost impossible. So engineers who work in biomedical research develop devices that simulate the environment of a human body. These simulation devices enable thorough experimentation to record cell reactions over time for all sorts of medicines, vaccines and environmental changes. For example, medical investigators and engineers work together to determine how cancerous cells respond to various treatments and numerous types of cell movement. As another example, the interdisciplinary field of microfluidics develops miniaturized technologies that are able to manipulate the flow and reaction of tiny amounts of fluids. Doing this takes fewer materials and results in speedier testing and analysis, helping to advance innovations in biology and medicine. These applications require that engineers fully understand flow rates and human body physiology.