The ATL Mark III Ultrasound Device represented a major breakthrough in medical imaging because it incorporated the first real time digital scan converter, which allow real-time and freeze frame display of ultrasound images on conventional video monitors. Advanced Technology Laboratories (ATL) was founded in 1969 by a group of engineers working on marine electronic systems. In 1974 ATL and the University of Washington signed the first of two technology transfer agreements (the second occurred in 1976) and began working in diagnostic medical ultrasound. ATL devloped several innovations, including the first pulsed Doppler device for evaluating heart function.