Here’s a tip on how to calculate the aortic valve area using the continuity equation. This video provides clarification on the often confusing continuity equation and Bridget Mazzuco, BBA, RDCS, RVT, demonstrates three easy steps to calculate AVA.
The piezoelectric (pressure electricity) effect was discovered by Pierre and Jacques Curie in 1880. The ultrasound machine’s transducer uses the ‘piezoelectric effect’ to send and receive sound waves that are used to generate ultrasound images. Inside the machine’s transducer, there are one or more quartz crystals which vibrate in response to an electric current and emit sound waves. When the sound waves bounce back toward these crystals, the process reverses causing sympathetic vibrations in the crystals – which in turn generate electricity that is measured and rendered into the ultrasound image. The process is analogous to the way audio speakers and microphones work. As a person speaks into a microphone, sound waves vibrate a diaphragm connected to an electrical coil which generates an electrical signal. When the electrical signal is passed to a speaker, the electrical coil vibrates a larger diaphragm to generate the sound. Besides ultrasound technology, the piezoelectric principle is used in a variety of other applications including musical instrument amplification and generating electricity from human movement.
Atrioventricular (AV) node
Atrioventricular (AV) node – A group of cells in the heart located between the upper two chambers (the atria) and the lower two chambers (the ventricles) that regulates the electrical current that passes through it to the ventricles.
Atrial tachycardia – A type of arrhythmia that begins in the heart’s upper chambers (the atria) and causes a very fast heart rate of 160 to 200 beats a minute. A resting heart rate is normally 60 to 100 beats a minute. To learn more about Atrial tachycardia, and how to identify it during your evaluations, check out upcoming Adult Echo hands-on training course that will provide hours of hands-on scanning.