Medical scientist and inventor of the first practical ultrasound scanner.

Donald attended school in Scotland before emigrating to South Africa with his family. He returned to study medicine in London, graduating from St Thomas' Hospital Medical School in 1937. He held a teaching post there until accepting the Regius Chair of Midwifery at the University of Glasgow in 1954.

Donald was instrumental in developing the first contact ultrasound scanner. Early results were disappointing and he initially lost the support of his colleagues. However a landmark case in which ultrasound led to a new diagnosis, saving a patient's life, led to recognition of its utility.

Ultrasound became standard practice in hospitals. One of its key uses is to maintain a check on the health of the developing foetus during pregnancy.

Donald also worked as a doctor and teacher. His publications included the popular textbook Practical Obstetric Problems.

A committed Christian, Donald was a strong critic of unnecessary abortion and vigorously opposed the 1967 Abortion Act. He was awarded an MBE for bravery during the Second World War and a CBE for services to medical science in 1973. The Inter-University School of Medical Ultrasound in Croatia was founded in his honour in 1981.