William Desmond McCallum M.D. received his B. Sc. degree in physiology and degree in Medicine at the Queen's University, Belfast, Northern Ireland. After completing his residensy in Obstetrics and Gynaecology, he became member of the Royal College of Obstetricians and Gynaecologists of England in 1971. In 1975 he obtained a research doctorate for postgraduate studies on feto-placental blood flow, and in the same year he emigrated to the United States. At the University of Washington, Seattle, he completed a 2-year fellowship in Obstetrics and Gynaecology and collaborated with the Ultrasound Division of the bio-engineering department in the development of doppler techniques in investigating blood flow parameters in the fetus. Part of his work was also on the estimation of fetal volume using ultrasound. He is credited as one of the very first researchers in the application of flow velocity waveform analysis in the feto-maternal circulation. Since 1977 he has been assistant Professor of Obstetrics and Gynecology at Stanford University, California, and has established an obstetrical ultrasound service both at Stanford and at an affliated hospital, Santa Clara Valley Medical Center in San Jose. He collaborated with electrical engineers and computer scientists on the analysis of blood flow velocity waveforms, developing fast fourier transformation algorithms and the three-dimensional reconstruction of organs derived from ultrasound scans. Back to History of Ultrasound in Obstetrics and Gynecology.