Gil Vella

Dr Gil Vella teaches in the area of physical sciences. He lectures students in such units as radiation physics, speech science, and bio-electric signals and instrumentation. His teaching skills attracted a Faculty Excellence in Teaching Award in 1991, and a University Excellence in Teaching Award in 1996. He has also provided a special series of HSC Physics lectures for the benefit of high school students. Dr Vella and his colleagues recently held a Faculty Information Technology in Teaching Grant, and are developing interactive multimedia packages for physics and physiology.

Dr Vella's research concerns the bio-effects of diagnostic ultrasound, in particular, the heating effects of ultrasound near bone. Modern diagnostic ultrasound equipment is capable of producing high power outputs and hence the potential to produce significant heating particularly near a bone interface. In fact, recent animal studies have shown that some pulsed Doppler devices are able to heat fetal and other tissue close to bone by up to 5.6° C due to the bone's high absorption of ultrasound. Furthermore, the temperature elevations are found to increase with increase in bone dimensions and progression in bone development, both of which are correlated with the gestational age. One of the aims in Dr Vella's research, therefore, is to identify which factors are most important in determining the ultrasonically-induced bone heating.

The World Federation of Ultrasound in Medicine and Biology (WFUMB) and national bodies such as the National Council on Radiation Protection and Measurement (USA) have suggested the use of theoretical worst case algorithms which give estimates of the heating effects resulting from clinical ultrasound exposures in various tissues. These algorithms are based on very limited data, particularly those involving the heating of bone. Hence the second aim of Dr Vella's research is to enlarge the empirical data base for bone heating which would provide a better foundation for refining the bone heating algorithms used for ultrasound units. Such a data base is essential if there is to be a greater universal acceptance of this output display.

Finally, Dr Vella is interested in the extra heating effects caused by the nonlinear effects of ultrasound when travelling in a low-loss medium (such as water) or in tissue-like materials.

E-mail	G.Vella@usyd.edu.au
Phone	+61 2 935 19626
Fax	+61 2 935 19520
Office	L229
Address	Discipline of Biomedical Science School of Medical Sciences Faculty of Medicine Cumberland Campus, C42 The University of Sydney PO Box 170 Lidcombe NSW 1825 Australia