This research addresses transducers and measurement systems using ultrasound for applications in bioengineering. The research goal is the development of an ultrasonic measurement system with a mechanically adjustable focus, achieved by use of a waveguide. The adjustable focus allows control of spatial resolution and penetration depth based on the physical profile of the acoustic field. By controlling these parameters, the measurement system may be used to investigate biological systems of variable size, shape, and density. After an initial study of waveguide materials, potential waveguides will be designed, fabricated, and coupled with transducers. Their beam profiles will be measured and compared with predictions. Laboratory tests will be developed to demonstrate application of the system to blood flow measurement and dynamic characterization of soft tissue.
