Organs and Artificial Organs

Rationale

The goal of this unit is to provide the necessary understanding of the heart and its parameters for the students to design and build an artificial heart. To simplify the process I will have my students concentrate on the left side of the heart, which is the larger pump that supplies blood to the entire body. I believe that my students will be able to grasp the role of the heart as a hydraulic pump and create mechanical solutions to simulate the beating of the heart. It is my hope that my students will be able to find mechanical solutions that partially mimic the functional properties of the left side of the heart.

This creative design process of engineering and system design will result in my students designing and creating their own solutions to the heart as a pump. I intend to utilize this creative process which consists of several steps: defining the problem; establishing individual roles within the group; determining the parameters of the required design; brainstorming about a variety of possible approaches; experimenting and testing the design in phases by breaking the problem into definable and solvable sub-systems; regularly looping back to earlier steps to check the design parameters and to evaluate the progress; setting timelines for the different stages of the process; creating at least one prototype, and evaluating the success of the project. In my experience as a teacher of creative design, it is essential to provide enough knowledge or access to knowledge to define the project successfully. I have also found that students need to be encouraged to seek creative solutions by being presented with some stimulating examples of related but not reproducible options that allow them to get started. The team needs to coalesce into a functional unit that is excited by the task sufficiently to address and overcome inevitable frustration generated by attempting to solve a formidable task. One of the most challenging aspects of the creative design process for a teacher is that it is the teacher's responsibility to provide a central project task and engaging options and materials that will instill a passion for the project and the incentive and capability of successfully completing the project. I am convinced that creating an artificial heart with circulatory system is a sufficiently compelling system to captivate my second year students who have studied mechanics and will be introduced by this process to fluid dynamics.

As indicated by the National Research Council (NRC) in its recent report, "K–12 science and engineering education should focus on a limited number of disciplinary core ideas and crosscutting concepts, be designed so that students continually build on and revise their knowledge and abilities over multiple years, and support the integration of such knowledge and abilities with the practices needed to engage in scientific inquiry and engineering design." ¹ This is exactly what this curriculum unit proposes to accomplish.

I have found that most students have little pragmatic experience with confronting a challenging problem that involves breaking the system down into parts in order to solve the overall project. It is incumbent upon me to imagine and explore a plethora of options and to provide a multitude of possible materials to pursue those options. There are a variety of types of artificial heart pumps, few of which function like the human heart. It is my goal to get my students to pursue both traditional mechanical pumps, such as propellers, as well as designs that are more associated with the contracting that the heart actually does by introducing springs, memory foam and other materials that will stimulate the students' creativity.

It is my intention to imbed these concepts in the experimental, hands-on activities and construction that the students experience as they pursue the goal of producing a working prototype of their pump and "circulation" system. It is my hope to harness this opportunity to create a fundamentally experiential and experimental unit utilizing concepts of engineering systems and design to create a prototype. The physics that we will explore is partly determined by the project but also partially determined by the direction that the students take in their design. Consequently, this unit is as much about the process of determining the scope of the project as it is about the biology, physiology and physics content. I will present the relevant physics as an integral part of the student's exploration into their design and the students' individual paths for creating successful pumps. I will provide the students with introductory experiences that will guide them towards comprehension of the task, enthusiasm for the design and creativity in the outcome. From my experience, these must all be intertwined. The materials provided will further inform the relevant physics concepts that are required.

The students will also be researching artificial heart and valve designs. The possibilities are very diverse and exciting. In addition, the need for artificial hearts is real, since heart disease remains the number one killer of adults in the US. ² When I first visited colleges, and was considering biomedical engineering, in the '80's, I remember how impressive and awe inspiring it was that successful artificial hearts were being developed. It appealed to me then and I believe will spark the interest and passion of my students because it captivates the imagination. As Mark Saltzman indicates in his book, "To many people, design of a synthetic replacement for the human heart is the most heroic goal in biomedical engineering." ³