CHAPTER 2: Doppler

“Velocity: Which way and How fast?”

• The change between the pitch of transmitted sound and the pitch of received sound is used to determine direction and speed of blood cells and cardiac tissue.

• Familiar audible sound example of the Doppler effect: The whistle of a moving train tells you train direction and train speed.

• Historical anecdotes:

  • - In 1842 Christian Doppler wrote that light from moving stars changes color (light frequency).

  • - In 1845 the Doppler effect was scientifically validated by using sound:

    A note from a trumpet player on a train moving at 40 mph was perceived as a tone higher than the identical note from a stationary trumpet player.

Source

• Bullot’s confirmation of Doppler’s theory. In Gilllespie EC (ed): Dictionary of Scientific Biography. Vol 4. New York, NY: Charles Scribner’s Sons; 1980:167.

• Other historic names in sound and ultrasound:

  • - Marin Mersenne (1588–1648) studied the vibration of stretched strings.

  • - Abbe Lazzaro Spallanzani (1727–1799) showed that bats navigate by echolocation.

  • - Curie and Curie described the piezoelectric effect in 1880.

  • - Lewis Fry Richardson registered a patent for iceberg detection using acoustic echolocation in air in April 1912. A month later he registered a similar patent for echolocation in water.

  • - Paul Langevin and Constantin Chilowsky filed two U.S. patents in 1916 and 1917 for the first ultrasonic submarine detector using an electrostatic method (singing condenser) for one patent, and thin quartz crystals for the other. The amount of time taken by the signal to travel to the enemy submarine and echo back to the ship, on which the device was mounted, was used to calculate the distance under water.

  • - S.Ya. Sokolov proposed an acoustic microscopy device in 1936 for producing magnified views of structures.

  • - Karl Theo Dussik, an Austrian neurologist, used transmitted (rather than reflected) ultrasound in 1941 to outline the ventricles of the human brain.

  • - W. D. Keidel used ultrasound in 1950 to examine the heart. He transmitted ultrasonic waves through the heart and recorded the effect of ultrasound on the other side of the chest. His purpose was to measure cardiac volumes.

  • - Helmut Hertz obtained a commercial ultrasonoscope in 1953. It was being used for nondestructive material testing. It was based on the work of Floyd Firestone, who applied for a U.S. invention patent in 1940.

  • - Hertz collaborated with Inge Edler, a cardiologist in Sweden. They used this commercial ultrasonoscope to examine the heart. This is considered by many as the beginning of echocardiography.

  • - In the early 1960s, investigators in Shanghai and Wuhan began with an A-mode ultrasound device, and then developed an M-mode recorder. They described fetal echocardiography, and contrast echocardiography.

Sources

• Coman IM, Popescu BA. Shigeo Satomura: 60 years of Doppler ultrasound in medicine. Cardiovasc Ultrasound. 2015;13:48.

• Curie P, Curie J. Developpement, par pression de l’electricite polaire dans les ...