I was reviewing information on various ultrasound scanners for our group, Morning Medicine, when I came across the following blurb for the Mindray M9:
Based on the popular ultrasound platform, the mQuardo, the Mindray M9 ultrasound is Mindray’s most advanced portable system. It is designed to greatly enhance your diagnostic experience via color Doppler, advanced signal transmission, single-crystal ultrasound transducers for improved resolution and penetration, and highly sensitive and accurate echo detection, among other features.
I was not familiar with the meaning of the term, single-crystal ultrasound transducers. A Google search of “What is a single crystal ultrasound transducer?” yielded the following results:
Alpinion Transducer Technology (discusses single crystal ultrasound transducer technology)
ALPINION’s transducer portfolio includes conventional piezo-ceramic, composite PZT and the latest single crystal materials. Single crystal material produces broadband frequency response and higher sensitivity, permitting its use in harmonic imaging with minimal loss of the acoustic signal. It results in more uniform wide-bandwidth imaging and thus offers higher resolution images to the user.
Through a unique and innovative single crystal transducer processing technology, ALPINION has produced the largest single crystal convex transducer ever fabricated, and the world’s first 3D/4D transducer made with single crystal material.
A single crystal transducer is characterized by a higher energy conversion efficiency and higher sensitivity than conventional piezo-ceramic materials; consequently, single crystal transducers can produce greater uniformity, and stronger penetration.
Alpinion Paper Explaining The Advantages of Their Single Crystal Transducer Technology [PDF]. Here are some excerpts:
So what is different about single-crystal material, PMN-PT, compared to ordinary ceramic PZT?
Foremost, it’s because ceramics that are made of random microcrystals cannot respond to electrical signals as efficiently, since most of them are not aligned properly to the electric field.
Advantage of PMN-PT single-crystal
The net effects of replacing ceramic PZT with single-crystal PMN-PT in a transducer can be summarized as follows:
First, less applied voltage is needed to make an acoustic signal, resulting in less waste heat and therefore fewer thermally limited modes of transducer operation.
Second, the transmitted and received bandwidths are both wider, meaning that more detailed, lower-noise images can be collected with a simple,conventional array architecture. Simpler arrays reduce the manufacturing cost and complexity compared to PZT transducers that require more components and need more processing to approach the same performance standards.
And finally, the single crystal produces more voltage when receiving an acoustic pressure wave, leading to better sensitivity and a higher S/N ratio. Single-crystal PMN-PT achieves all these benefits over PZT because of its inherent properties; there is no dispute about its advantages.
Everybody everywhere acknowledges the benefits of PMN-PT transducers over ordinary PZT and its antiquated
cell-phone ringer technology, including greater sensitivity, wider bandwidth, higher conversion efficiency, and lower
noise. There is virtually no other way to show these kind of improvements in sonographic imaging except with PMN-PT
single-crystal technology. The only conventional PZT transducer which approaches the kind of performance that all ALPINION’s single-crystal products achieve is a single example of an expensive, complicated, low-frequency array
made with triple PZT layers and triple matching layers that’s offered by one major ultrasound transducer
There’s a good reason why this kind of elaborate array architecture isn’t duplicated in any other transducer.
At ALPINION we match or exceed the performance of the very best competing transducers every single day with
our PMN-PT single-crystal products, and we do it with no more construction complexity than what is found in common PZT transducers. What the ALPINION has developed is the way to apply the fragile, expensive PMN-PT crystals with such high yield and reliability that the whole manufacturing process appears hardly more complex than anybody else’s.
This major breakthrough in the application of PMN-PT is now being leveraged in every new transducer technique
and technology, and we fully expect that it will continue to improve the ALPINION’s position in the medical