scholarly journals Novel Bandwidth Expander Supported Power Amplifier for Wideband Ultrasound Transducer Devices

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2356 ◽  
Author(s):  
Kyeongjin Kim ◽  
Hojong Choi
Keyword(s):  
Blood Vessel ◽  
Penetration Depth ◽  
Power Amplifier ◽  
Image Resolution ◽  
Ultrasound Transducer ◽  
Specific Information ◽  
Wide Bandwidth ◽  
Ultrasound System ◽  
Depth Sensitivity ◽  
Frequency Ultrasound

Ultrasound transducer devices have their own frequency ranges, depending on the applications and specifications, due to penetration depth, sensitivity, and image resolution. For imaging applications, in particular, the transducer devices are preferable to have a wide bandwidth due to the specific information generated by the tissue or blood vessel structures. To support these ultrasound transducer devices, ultrasound power amplifier hardware with a wide bandwidth can improve the transducer performance. Therefore, we developed a new bandwidth expander circuit using specially designed switching architectures to increase the power amplifier bandwidth. The measured bandwidth of the power amplifier with the help of the bandwidth expander circuit increased by 56.9%. In addition, the measured echo bandwidths of the 15-, 20-, and 25-MHz transducer devices were increased by 8.1%, 6.0%, and 9.8%, respectively, with the help of the designed bandwidth expander circuit. Therefore, the designed architecture could help an ultrasound system hardware with a wider bandwidth, thus supporting the use of different frequency ultrasound transducer devices with a single developed ultrasound system.

High-Frequency and Ultra-High Frequency Ultrasound: Musculoskeletal Imaging up to 70 MHz

2020 ◽  
Vol 24 (02) ◽  
pp. 125-134 ◽  
Author(s):  
Domenico Albano ◽  
Giacomo Aringhieri ◽  
Carmelo Messina ◽  
Luca De Flaviis ◽  
Luca Maria Sconfienza
Keyword(s):  
High Frequency ◽  
Peripheral Nerves ◽  
Imaging Technique ◽  
Case Series ◽  
Image Resolution ◽  
Ultrastructural Changes ◽  
High Frequency Ultrasound ◽  
Ultra High Frequency ◽  
Time Dynamic ◽  
Frequency Ultrasound

AbstractMusculoskeletal (MSK) ultrasound has well-established advantages, able to investigate very small structures with high resolution and a quick and real-time dynamic evaluation with the possibility of contralateral comparison. Thus ultrasound has kept its own almost exclusive fields of application in daily clinical practice, and it is considered the first-level imaging technique to assess tendons, bursae, and capsuloligamentous structures of small peripheral joints as well as peripheral nerves. Up to now, however, clinical MSK ultrasound imaging could not go beyond the first 1 to 2 cm under the skin, using high-frequency probes up to 18 to 20 MHz with spatial resolution just below millimeters. We present the impressive technical advancements leading to image resolution as low as 30 µm using ultra-high frequency ultrasound (UHFUS) probes up to 70 MHz. High-frequency ultrasound and UHFUS, with frequencies ranging from 22 to 70 MHz, are promising tools to evaluate very superficial structures. In the MSK system, only two articles have assessed its value in limited case series. Future developments may be aimed to better assess ultrastructural changes of very superficial peripheral nerves and other thin structures such as pulleys, retinacula, and tendons.

Development of a 20-MHz wide-bandwidth PMN-PT single crystal phased-array ultrasound transducer

Ultrasonics ◽  
2017 ◽  
Vol 73 ◽  
pp. 181-186 ◽  
Author(s):  
Chi-Man Wong ◽  
Yan Chen ◽  
Haosu Luo ◽  
Jiyan Dai ◽  
Kwok-Ho Lam ◽  
...  
Keyword(s):  
Single Crystal ◽  
Phased Array ◽  
Ultrasound Transducer ◽  
Wide Bandwidth ◽  
Phased Array Ultrasound ◽  
Array Ultrasound

scholarly journals The Need of Slanted Side Holes for Venous Cannulae

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Joong Yull Park
Keyword(s):  
Numerical Modeling ◽  
Shear Rate ◽  
Blood Vessel ◽  
Penetration Depth ◽  
Flow Rate ◽  
Analysis Study ◽  
Side Hole ◽  
Good Flow

Well-designed cannulae must allow good flow rate and minimize nonphysiologic load. Venous cannulae generally have side holes to prevent the rupture of blood vessel during perfusion. Optimizing side hole angle will yield more efficient and safe venous cannulae. A numerical modeling was used to study the effect of the angle (0°–45°) and number (0–12) of side holes on the performance of cannulae. By only slanting the side holes, it increases the flow rate up to 6% (in our models). In addition, it was found that increasing the number of side holes reduces the shear rate up to 12% (in our models). A new parameter called “penetration depth” was introduced to describe the interfering effect of stream jets from side holes, and the result showed that the 45°-slanted side holes caused minimum interfering for the flow in cannula. Our quantitative hemodynamic analysis study provides important guidelines for venous cannulae design.

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