This chapter presents a case study on The Accidental Discovery of the Pacemaker using the discovery engineering process. In this lesson, students explore the development of the pacemaker and discover that some heart conditions are controlled with the assistance of a pacemaker. Students learn about different types of heart conditions and consider how an electrical device such as the pacemaker can be used to treat cardiac conditions. They review patient histories, so they can counsel different patients interested in having a pacemaker implanted. Last, students will create a plan to use an electrical device to address a different human health issue. A list of materials, teacher background information, teacher notes, references, resources, assessments, and standards are provided. This book selection also includes the Table of Contents, About the Authors, Acknowledgments, Introduction, and Index.