Associate Director, Biomedical Engineering Lab
Jeff Ketterling joined the Lizzi Center for Biomedical Engineering at Riverside Research in 1999 as a member of the research staff and, since May of 2012, has been the Associate Director for the group. He served as the principal investigator for programs supported by the National Institutes of Health that deal with high-frequency annular arrays for small-animal and ophthalmic imaging, high-frequency acoustic contrast agents for microcirculation imaging in small animals and eyes, and hydrophone arrays for characterizing the instantaneous acoustic fields of lithotripters. Currently, Dr. Ketterling is the principal investigator of an NIH grant dealing with the role of vitreous degeneration in myopia.
Dr. Ketterling was Technical Chair for the Biomedical Acoustics Committee of the Acoustical Society of America from 2008–2011. He is a member of the Medical Ultrasonics Technical Program Committee of the IEEE International Ultrasonics Symposium. Dr. Ketterling serves as an Associate Editor for Ultrasonic Imaging and IEEE Trans. Ultrason. Ferroelect. Freq. Contr. As part of his professional activities, Dr. Ketterling presents his work at international conferences, publishes his work in peer-reviewed journals, acts as a peer reviewer for numerous acoustic-related publications, and serves on NIH study sections.
Dr. Ketterling received a BS in electrical engineering from the University of Washington in 1994 and a PhD in mechanical engineering from Yale University in 1999. His thesis focused on experimental studies of phase-space stability in single-bubble sonoluminescence.
Dr. Ketterling is researching high-frequency ultrasound imaging of the human eye using 20 and 40 MHz annular-array technology and of mouse embryos using 40-MHz annular arrays. After establishing feasibility, Dr. Ketterling refined their system to perform real-time, hand-held imaging and a clinical prototype is in use at Columbia University Medical Center. They have also combined imaging with coaxial photoacoustic imaging to generate co-registered ultrasound and photoacoustic images. This approach provides new information related to vasculature in small animals and opens up new possibilities to characterize normal and abnormal vascular development in mouse embryos.
Dr. Ketterling has also been pursuing the use of hydrophone arrays for measuring high-pressure acoustic fields in shock-wave lithotripters. Dr. Ketterling and his team have fabricated numerous prototypes with different array geometries and have successfully obtained measurement data from research lithotripters in collaboration with colleagues at the University of Washington and Boston University. The hydrophone arrays developed by Dr. Ketterling permit new insight into lithotripter acoustic fields and the experimental results will assist in improving numerical models of stone destruction and future designs of clinical lithotripters.
Finally, Dr. Ketterling has been studying the acoustic response of individual acoustic contrast agents, with an emphasis on polymer-shelled agents, to better understand how it can be used for non-linear imaging with a specific emphasis on small-animal imaging. Dr. Ketterling’s team has developed a static-pressure method of characterizing the fragility of agents as they are compressed and also a method to simultaneously image the agents as they buckle and rupture. The data from these experiments provide information on the elastic properties of the agents. In addition, a technique has been developed to obtain backscatter echoes from single contrast agents as they flow through the focal region of a transducer. This experimental approach permits data to be collected for thousands of agents in a short time span and provides a better statistical representation of how a bubble population responds to a given acoustic excitation.
Dr. Ketterling’s research interests include
- High-frequency ultrasound for ophthalmic and small-animal imaging
- Combined photoacoustic and high-frequency-ultrasound imaging for microvascular imaging
- Hydrophone arrays for instantaneous pressure measurements in very-high-pressure acoustic fields, such as those found in shockwave lithotripters
- High-frequency transducer fabrication with an emphasis on copolymer-based arrays and, in particular, annular arrays used for high-frequency imaging
- Acoustic contrast agents used to image microcirculation in small-animal models
- Fundamental acoustical and mechanical characterization of acoustic contrast agents
- Multi-modality contrast agents, such as combined photoacoustic and MRI agents