Ian Donald was a controversial character who was revolutionary in many aspects of obstetric practice. An inspirational teacher and a caring clinician, his greatest contribution to his profession was in medical ultrasound. 'If you seek his memorial, look around you - and in every maternity hospital you will see ultrasound in use.' In this book, the journey from the initial experiments with early 'flaw detectors', through to Ian's single-minded determination to develop the technique into a useful diagnostic tool (resulting in his eventual success) is described both in his own words and from the memories of the authors, who were intimately involved in the process.