May 1954, Donald delivered the Blair-Bell Lecture at the Royal College of Obstetricians and Gynaecologists. He spoke about atelectasis neonatorum (the partial collapse of an infant's lung) and how his respirator could improve managing the condition. In the same period he met John J. Wild in London, who had discussed the use of ultrasound with him. Wild had used pulse-echo ultrasound to visualize abnormal tissue in the human breast. In September 1954, Donald was appointed by Hector Hetherington to Regius Professor of Midwifery. Hetherington had to confirm the position with the Secretary of State for Scotland, as it was a government appointment and Donald was proud of his commission that was signed personally by the Queen. Although Donald was impressed by Hetherington, he made it a condition of his employment that Hetherington had to promise to build a new maternity hospital in Glasgow, which was done. Obstetric ultrasound Whilst Donald was Professor of Regius Midwifery at Glasgow University, he first explored the use of obstetric ultrasound in the 1950s in a collaboration with John MacVicar, a registrar and obstetrician in the Department of Obstetrics and Gynaecology at the Western Infirmary, and Tom Brown, an industrial engineer who worked for Kelvin & Hughes Scientific Instrument Company, developed the first contact compound sector scanner, and wrote an article in The Lancet: "Investigation of Abdominal Masses by Pulsed Ultrasound". The article contained the first published ultrasound image of a fetus. The development of Donald's interest in ultrasound started when one of his patients introduced her husband to him. The patient's husband was the director of the boiler fabrication company Babcock and Wilcox, and he offered a tour of the plant to Donald, who accepted. The Renfrew company was a large user of industrial ultrasound that was used to check for crack and flaws in welds. Donald's purpose in making the visit to Renfrew on 21 July 1955 was to determine if the industrial detecting equipment could be used to differentiate types of tissue. He arrived at the plant with a number of fibroids and a large ovarian cyst taken from gynaecology patients. When Donald met Bernard Donnelly, an employee in the research department of the boilermaker, Donald asked him to demonstrate the device's use by taking an ultrasound image of the bone of his thumb. Donald experimented with the tissue samples along with a huge steak the company had provided for a control,