The History of Ultrasounds: From Bats to Babies
While common in every doctor’s office and hospital in the developed world, ultrasounds haven’t been around very long. Ultrasound technology and machines have only existed in medicine for less than a century and weren’t perfected until the late 1950s. And, like all medical advancements, ultrasounds didn’t appear overnight. It took inventors and physicists many years to develop ultrasound. From simple experiments on bats to wartime sonar for tracking submarines to a rough prototype of the Logiq E9 made in Scotland, one breakthrough after another kept the technology advancing. Eventually, all these creations would lead to the ultrasounds we know today.
In 1794, Italian physiologist Lazzaro Spallanzani was the first to discover echolocation in bats—he noticed that bats were able to fly at night without hitting things. Echolocation is when a bat emits a high-frequency sound to gauge the distance of objects based on how long it takes for the sound wave returns to them. As part of his study, Spallanzani would suspend strings with bells attached to the end in his home and observe the bats fly about, never hitting them. His discovery of echolocation is the basis of sonar technology and ultrasound physics.
The findings of Spallanzani, while important, didn’t advance for over 80 years. In 1877, brothers Pierre and Jacques Curie made the next big breakthrough. Their discovery of piezoelectricity was a turning point in the development of ultrasound. The Piezoelectric Effect is the ability of solid materials to generate electricity in response to applied mechanical stresses. The brothers exhibited the effect by using salt, sugar, quarts, and other crystals. During the following decades, the experiments stayed in the lab so the brothers could discover the full potential of their scientific breakthrough.
They wouldn’t have to wait long, as one historical event led to another. After the sinking of the Titanic in 1912, Paul Langevin was working to develop a way for ships to find icebergs at night. His experiment worked off of the principles of piezoelectricity and consisted of a thin layer of quartz crystals between steel plates, submerged in water. His sonar machine would send low-frequency waves out and receive them to find objects in the dark and underwater—it was successful. The start of World War I would further the use of the sonar device as a tool to detect submarines. It saw moderate success during the war but had limitations on what it could do, as it was more a passive listening device.
Medical Ultrasound Takes Shape
Further developments in the early twentieth century helped advance sonar into the medical ultrasound technology we know it to be today. Ultrasonic waves were able to detect flaws in metal and even treat arthritis in European soccer players. However, it wasn’t until 1942 that sonograms lead to a medical diagnosis. Karl Dussik, a neurologist at the University of Vienna, used ultrasonic beams to detect brain tumors—he is the pioneer of diagnostic ultrasound. To examine the brain, Dussik would place a transponder on either side of the subject’s head. He would then partially submerge the subject and device in water and would create waves that moved at a known rate. The resulting image from this setup would transfer onto heat-sensitive paper. He called his new process hyper phonography and felt it should not stand alone but used as a tool to further study brain diagnostics.
Dussik showed the world that ultrasound has medical applications and diagnostic capabilities. His discovery advanced ultrasound faster than anything before. Several scientists and physicians built upon his work. As such, in 1949, American professor George Ludwig received credit for being the first to use ultrasound in diagnosing gall stones. The early 1950s also saw success with ultrasound images. Come 1957, a Scottish engineer and physician would invent the first successful ultrasound diagnostic machine that would change the world forever.
The Birth of Prenatal Ultrasound
Ian Donald has the distinction of forging ultrasound for medical purposes. He began medical school in London in 1937, only to have World War II interrupt his education. During this time, he served with distinction in the medical branch of the Royal Air Force. His exposure to radar and sonar technologies during the war and his passion for the field led him down the path to discovering medical sonar. When he returned to his studies, he graduated as an obstetrician—a doctor that specializes in childbirth, pregnancy, and a woman’s reproductive system. During that period, doctors primarily used ultrasound for detecting flaws in metal; however, Donald saw the potential and felt he could apply it to obstetrics.
Tom Brown and Ian Donald met in 1956. Brown was a young man of 23, but he had already worked on an automatic flaw detector for industrial products. When he heard Donald was performing experiments with human tissue and the flaw detector, Brown made an inquiry. He learned Donald was attempting to find out if the machine could penetrate human tissue and make the inside visible. Once he discovered the nature of the experiments, Brown arranged a meeting and the two began a collaboration. The two began to design the prototype for an ultrasound machine. And once they agreed on a design, Brown began to build it. The prototype consisted of all kinds of materials—whatever was available. Later, Tom Brown would say of the building process, “It was a case of scrounging parts wherever I could.”
In 1958, Ian Donald published a paper in The Lancet titled, “Investigation of Abdominal Masses by Pulsed Ultrasound”—he was introducing the ultrasound machine to the world. At first, critics panned his invention, until they saw him use it. As soon as Donald diagnosed a female patient’s ovarian cyst with his machine, people started taking him seriously. As such, Scotland became the center of the medical universe. His vision, along with help from Tom Brown, led Ian Donald to become the father of OBGYN ultrasounds.
Ultrasound technology developed quickly, and we continue to make advancements with it today. The basic principles of using sound waves to create an image are still the same; however, now the imagining appears digitally on monitors. Further, we now have 3D imaging, which captures the fine detail of babies in utero and helps doctors to better diagnose potential problems. Thanks to the vision of pioneers throughout history, ultrasounds are now available to almost everyone.