The ultrasound probe, also known as a transducer, is the part of the ultrasound system that touches the patient’s body. It holds the crystals that send and receive the sonic pulses.
An ultrasound transducer converts electrical energy into mechanical (sound) energy and back again, based on the piezoelectric effect. It is the hand-held part of the ultrasound machine that is responsible for the production and detection of ultrasound waves.
The ultrasound transducers differ in construction based on:
✅Piezoelectric crystal arrangement
✅Aperture (footprint)
✅Frequency
Maintaining A Probe
Transducers, extremely delicate in nature, need to be kept in top condition. Even the slightest nick or dent in the lens can pervert and damage the image quality on the screen. Simply put, using a combination of sound waves and electric waves, the probe generates voltage that translates into images on the Ultrasound monitor. This is the reason why any interference with the lens can alter the imagery; changing the shape, even by a tiny nick, dent or scratch, impacts the sound and electric waves – distorting how the monitor deciphers the information it is receiving via the probe.
Interior Contents of the Convex Probe
Ultrasound Probe Technology Explained
Ultrasonic imaging is the use of ultrasound waves for diagnostic or therapeutic purposes. Ultrasound machines and probes allow doctors to see problems with organs, tissues, and vessels without needing to make an incision. Unlike other imaging techniques, ultrasound doesn’t use radiation. Because of this, ultrasounds are the preferred method for viewing a baby during pregnancy.
Similar to golf, where the goal is to get the most accurate club that can hit the distance you need, the same can be applied to ultrasound probes. For deeper scans, you need a low frequency. For more superficial scans, you need a high frequency. What you must balance is depth vs. frequency in that you want the clearest, most accurate picture possible.
Bandwidth is a primary measurement of an ultrasound transducer’s capabilities. It is the range of frequencies that the probe emits sound waves from the piezoelectric crystals. Ultrasound probe bandwidth can be compared to golf – the further you want to hit, the lower the number of golf clubs you use. On the other hand, the more accurate you need to be, the higher number of golf clubs you want to use.
The field of view is a secondary measurement of an ultrasound transducer’s capabilities, and it is of how large of an area the probe’s image displays while scanning. Linear probes only scan straight down, so their field of view is most likely explained in mm terms. Other probes have a curved array, so their field of view is described by degrees. For the probes that have their field of view described in degrees, think of them as a protractor. If it’s 120 degrees, it will have a field of view of 0-120 degrees on the protractor.
