Abstract
Congenital heart defects affect over 40,000 newborns each year in the United States. Many of these defects require multiple open-heart surgeries during the first few years of life. Increasingly, physicians are adopting interventional cardiac procedures to address heart defects using stents. Stent crimpers are devices used to compress cardiac stents onto catheters and inflation balloons to facilitate insertion into patient vasculature. Currently, a stent crimper capable of achieving crimped diameters small enough for safe insertion into pediatric patients does not exist. Physicians resort to breaking adult stent crimpers or using alternative methods, such as crimping by hand, to achieve sufficiently small diameters, introducing added patient risk due to prolonged operation time and irregularly crimped stents. The technical report describes the ideation, design, and iteration of novel pediatric stent crimper prototypes. Several prototypes were produced and tested using a clinical model that mirrors the equipment and setup employed during a pediatric catheterization procedure. User feedback and data collection revealed that the Mercury Crimper prototype produces stents of diameters rivaling industry standards while improving upon usability, manufacturing time, and sustainability. The Mercury Crimper achieves a device minimum diameter of one millimeter, is operated with one hand, and is manufactured using a 3D resin printer using files that are downloadable and distributable. This project was informed and proposed by a pediatric cardiologist, Dr. Michael Shorofsky. To complete this technical project, in addition to physical prototyping and testing, we also shadowed medical procedures and received direct feedback from the clinician. Ultimately, herein, we describe the development of a widely accessible device that addresses key issues in the field of pediatric cardiology.
Ventricular fibrillation has multiple causes including preexisting genetic conditions or acute heart disease. It occurs when the lower chambers of the heart quiver uncontrollably, preventing proper blood flow and oxygenation. The AED is a device that records a patient’s electrocardiogram and administers electrical shocks, if needed, to stop the life-threatening effects of ventricular fibrillation (Liddle et al., 2003). This sociotechnical thesis examines the unique aspects of the AED that make it a radically accessible, user-friendly technology and the positive benefits associated with its engineering design. The questions guiding my research are “How are the audiovisual dialogue features of the AED particularly useful to ensuring proper, timely care for patients in the field?” and “What lessons in design can we learn from the AED, and how can we apply these lessons to other technologies?”
These questions are significant because heart disease and associated complications are the leading cause of death in the United States, affecting millions of individuals every year (National Center for Health Statistics, 2025). Roy Liddle et. al. show that fibrillation events are most successfully resolved when addressed within 90 seconds of onset (Liddle et al., 2003). Thus, an AED’s effective communication of information rapidly and clearly to its users is a critical design feature. The AED makes considerable strides towards extending the lifesaving capabilities of medical teams within hospitals to the layperson and thus has valuable lessons to offer us in terms of medical device engineering design. These two projects are broadly connected through the field of cardiology. The technical project highlights the production of a cardiac stent crimper for use in pediatric interventional cardiac procedures, and the sociotechnical thesis describes the unique design aspects of the AED that make it user-friendly and effective in high stakes, life saving operations. Both projects give thorough consideration to engineering design and how individual design choices affect the user. These projects are especially concerned with usability, though the technical project focuses on physical practicality, and the sociotechnical thesis focuses on the use of dialogue prompts to facilitate AED use. The sociotechnical thesis incorporates added discussion of science, technology, and society topics and views the AED through the unique lens of Actor-Network Theory. Though the technical project does not take this perspective, it is unique in that it was informed and guided by a clinician in the field. Taken together, the written works contribute to one whole by providing an abstract and practical consideration of biomedical devices used in cardiac applications.
