The history of ultrasound can be traced to Lazzaro Spallanzani. In 1790 he experimented with bats and found that they maneuvered through the air using their hearing rather than sight. In 1801, physicist Thomas Young worked with light and found that light waves can be shifted so two beams can either combine to become stronger or cancel each other out. Jean-Daniel Colladon a Swiss physicist/engineer discovered sonography with an underwater bell in 1826. He accurately determined the speed of sound through water. n 1881,Pierre Curie found a connection between electrical voltage and pressure on crystalline material. This was the breakthrough that was needed to create the modern ultrasound transducer. After the sinking of the Titanic, Paul Langevin invented the hydrophone to detect icebergs. This was the first transducer. A device that was able to send and then receive low frequency sound waves. The hydrophone was later used to detect submarines in world war I. This was a major step in the history of ultrasound. Dr. Karl Dussik an Austrian psychiatrist was first to use ultrasound pictures in an attempt to diagnose brain tumors in the late 1930's. The procedure was called "hyperphonography". He used heat sensitive paper to record echos. Ultrasound imaging got its start. Dr. George Luwig University of Pennsylvania in the late 1940's, was first to record and study the difference in sound waves as they traveled through tissues, organs, muscles, and gallstones in animals. This was a major step forward in the history of ultrasound.

You no longer know which site to go to for help getting your figure back. This site introduces you to all possible diets. So, everyone has their own path and their own method.