History of Diagnostic Medical Sonography Flashcards
What is the definition of sound?
Sound is a form of energy produced when a vibrating source causes the molecules within a medium to move back and forth.
Who are the two Greek pioneers? What did they study? What is a sonometer?
Aristotle and Pythagoras. They studied the movement of sound through air.
“Sonometer” which demonstrates the relationship between pitch and frequency.
Who are the four people from the 1500-1600s? What did each one accomplish?
1.) Da Vinci - identified the equality between the angle of reflection and angle of incidence.
2.) Galileo - demonstrated that frequency of sound waves determines pitch.
3.) Sir Isaac Newton - theory of velocity
4.) Robert Boyle - recognized for sound to travel it has to go through a medium. Laid the groundwork for using ultrasound gel.
Who are the four people from the 1800s? What did each one accomplish?
1.) Augustin Fresnel - theory of wave diffraction
2.) James Joule - described ferromagnetic effect (unit of measurement for energy.)
3.) Christian Johann Doppler - discovered that the pitch of the sound wave will vary if the source of the sound is moving. Doppler Effect named in his honor.
4.) Jacques and Pierre Currie - credited with the Piezoelectric Effect.
What is the Piezoelectric Effect?
The Piezoelectric effect states that certain materials can generate an electrical charge and change shape in response to applied mechanical pressure.
What did Paul Langevin do/accomplish? (WW1)
Paul Langevin studied sound frequency and intensity in water by studying submerged objects based on the frequency and intensity of sound waves.
Device used is known as HYDROPHONE. This served as a basis for SONAR in WW2
Also discovered that sound could have harmful effects.
What is SONAR and what does it stand for?
SONAR - Sound Navigation and Ranging. Was discovered and used for defense purposes. Technology utilized sound that was sent through water, bounced off an object, then returned to the source. Foundation for our present boat - Fish Finders.
What are examples that use Doppler effect?
Radar detectors, motion detectors, burglar alarms, and meteorologists
Who was Dr. Karl Dussik? What did he do?
He was from Austria.
First to apply ultrasound for medical purposes.
Positioned two transducers on opposite sides of the head to image the lateral ventricles of the brain and discovered tumors and lesions could be detected.
Images referred to as “HYPERPHONOGRAMS”
Who are George Ludwig? What did he do?
He was from the US.
He used pulse-echo ultrasound to diagnose gallstones and foreign bodies embedded in animal tissue.
Who was (John) Julian Wild? What did he do?
He was from the US.
He found that cancerous tissue thickness differed from normal tissue thickness.
Who was John Reid? What did he do?
He was an engineer.
Together with Wild they developed 1st B transducer used for breast imaging.
“Water tip”
Also developed the first system for echocardiography in the US.
Who was Douglas Howry? What did he do?
He was a radiologist.
His interest was producing images of anatomy by immersing body part/subject into water.
He produced the 1st cross sectional picture.
Who was Joseph Holmes? What did he do?
He joined Howry to discover that moving the transducer in two paths create a more complete anatomic picture. “SOMAGRAM”.
Used a B 52 Gun Turret Tank: mechanical transducer circles tank; subject weights down to limit motion artifact.
Howry and Holmes realized the Gun Turret was not practical on sick patients - which led to development of “pan” scanner.
What is the “pan” scanner?
It was water encased in a pan. The patient sat next to the pan and the transducer moved through the pan.
