Date of Award


Degree Type



Chemical and Biomedical Engineering

First Advisor

Fleischman, Aaron J.

Subject Headings

Ultrasound transducers, Intravascular ultrasonography, Piezoelectric transducers, Imaging systems in medicine, Microelectromechanical systems, Medical imaging, High frequency ultrasound, IVUS, Ultrasound transducers, Ultrasound transducers, Harmonic imaging, Pulse inversion


Intravascular ultrasound (IVUS) is increasingly employed for detection and evaluation of coronary artery diseases. Tissue Harmonic Imaging provides different tissue information that could additionally be used to improve diagnostic accuracy. However, current IVUS systems, with their unfocussed transducers, may not be capable of operating in harmonic imaging mode. Thus, there is a need to develop suitable transducers and appropriate techniques to allow imaging in multi modes for complementary diagnostic information. Focused PVDF TrFE transducers were developed using MEMS (Micro-Electro-Mechanical-Systems) compatible protocols. The transducers were characterized using pulse-echo techniques and exhibited broad bandwidth (110 at -6dB) with axial resolutions of Such promising results suggest that focused, broadband PVDF TrFE transducers have opened up the potential to incorporate harmonic imaging modality in IVUS and also improve the image quality. In addition, the transducer's multimodality imaging capability, not possible with the current systems, could enhance the functionality and thereby the clinical use of IVUS