Faculty Mentor: Karen Yan
Student: Robert Seither
Heart disease is the primary cause of death in the United States. Cardiac Magnetic Resonance Imaging (MRI) technology has been used to diagnose and evaluate a number of diseases and conditions. Given the inherent difficulty in imaging the heart in motion, cardiac MRI studies often use heart phantoms made of rubber like materials with known material properties as a means of validation. This project focuses on tissue damage caused by myocardial infarction (heart attack). Understanding the underlying change of the damaged heart tissue will provide critical information for diagnosis and treatment.
The objective of this project is to develop a dynamic heart phantom (DHP) capable of simulating true physiological motion utilizing models of the heart at different stages of damage that can be used with MRI to compile a database correlating the stiffness changes to tissue damage. Sylgard 527 A&B dielectric silicone gel was selected as the base material due to its similarity to myocardium for MR imaging and ease of varying stiffness.
Throughout the MUSE program, in order to produce consistent samples, different molding methods were examined with focus placed on determining a viable release agent and making full size samples. An aluminum foil lining with Dry-Film Teflon release agent produced the best results. Compression testing was conducted on various gel samples and ANSYS hyperelastic material curve fitting was used to develop a model of the gel’s material properties. A preliminary redesign of the phantom region was carried out.
For future work, the redesign will be finalized, manufactured and tested. The results will be compared with a computer model of the system made possible by the determined material property data. The molding techniques developed will be applied to the creation of heart models with varying stiffness. Finally, tests will be performed using the DHP apparatus in the MRI machine at the University of Pennsylvania.