[4][5] Satomura initially worked in areas of physics and in 1955 applied microwave and ultrasonic radiation to study defects in industrial materials.

In December 1955 they published their first measurements of the Doppler shift of ultrasonic signals from a beating heart irradiated by 3 MHz waves.

[6] This work was extended to design a device measuring the Doppler shifts from pulsating blood vessels, which was described in the Journal of the Acoustical Society of America in 1957.

His collaborator Ziro Kaneko, a neuropsychiatrist, proposed to use this technique for monitoring blood flow in the human brain to distinguish the Alzheimer and cerebrovascular diseases.

Although a similar device named a "pulsed ultrasound flowmeter" was designed by the Dean Franklin group at the University of Washington, Seattle, USA, its sensor had to be directly attached to the blood vessel wall.