Keynote 5 High Intensity Focused Ultrasound (HIFU) for Biomedical and Dentistry Application
Date/Time Friday, 3 May 2013 / 09:10 – 09:50
Venue Riverfront Ballroom

Prof. Boo Cheong KHOO
Department of Mechanical Engineering,
Faculty of Engineering &
Program co-Chair, Computational Engineering of SMA-II (Singapore-MIT Alliance)
National University of Singapore, Singapore

BC Khoo graduated from the University of Cambridge with a BA (Honours, 1st Class with Distinction) in 1980. In 1984, he obtained his MEng from the NUS and followed by PhD from MIT in 1989. He joined NUS in 1989. From 1998 to 1999, he was seconded to the Institute of High Performance Computing (IHPC, Singapore) and served as the deputy Director and Director of Research. In 1999, BC returned to NUS and spent time at the SMA-I (Singapore MIT Alliance) as the co-Chair of High Performance Computation for Engineered Systems Program till 2004. In 2005, under the SMA-II, he was appointed as the co-Chair of Computational Engineering Program.

BC Khoo serves on numerous organising and advisory committees for International Conferences / Symposiums held in USA, China, India and Singapore. He is a member of the Steering Committee, HPC (High Performance Computing) Asia. He has received a Defence Technology Team Prize (1998) and the prestigious Royal Aeronautical Prize (1980, UK). Among other numerous and academic and professional duties, he is the Associate Editor of Communications in Computational Physics (CiCP) and Advances in Applied Mathematics and Mechanics (AAMM), and is on the Editorial Board of Ocean Systems Engineering (IJOSE), The Open Mechanical Engineering Journal (OME) and The Open Ocean Engineering Journal.

In research, BC s interest are in:
(i) near-wall hot-wire response and measurements
(ii) underwater shock and bubble dynamics
(iii) scalar transport across the turbulent air-sea interface.

He is the PI of numerous externally funded projects including from the Defense agencies to simulate the WSSA and the dynamics of bubble(s) with extension to cavitation. His work on water circulation and transport across the turbulent air-sea interface has received funding from BP International for predicting the effects of accidental chemical spills.


We study the physical phenomena and the application of HIFU (High Intensity Focused Ultrasound) using simulation and experiment. The experiment was done with a bowl-shaped focused ultrasound system. High speed videos of the generation of cavitation bubbles at the focal point of the HIFU are captured. We observed interesting bubble cloud structures, bubble movements and stationary bubble oscillations. The system is then applied for dentistry applications. Firstly we use the HIFU to drive antibacterial nanoparticles into dentinal tubules for disinfection in root canal treatment. Initial results show delivery of these nanoparticle deep into the dentinal channels which are a few microns in size. Next we cultivate E. Faecalis biofilm, a common bacteria colony found in the mouth and teeth, on petri dish and in human tooth. Then we subject them for removal under strong HIFU for a period of time. We obtain positive results in the biofilm removal with the increasing HIFU sonification time. Separately, we simulate the interaction of a bubble with pulsed ultrasound and in an ultrasound field near bio-materials such as fat, muscle and bone. The simulation shows extreme growth and collapse of the bubble under certain conditions. It is found that the formation and direction of the water jet during bubble collapse is highly dependent on the properties of the bio-materials nearby. These studies provide a foundation for better understanding of HIFU and its uses in medical treatment.