An FPGA-based ultrasound imaging system using capacitive micromachined ultrasonic transducers

2012 ◽  
Vol 59 (7) ◽  
pp. 1513-1520 ◽  
Author(s):  
Lawrence L. P. Wong ◽  
Albert I. Chen ◽  
Andrew S. Logan ◽  
John T. W. Yeow
Keyword(s):  
Ultrasound Imaging ◽  
Imaging System ◽  
Ultrasonic Transducers ◽  
Capacitive Micromachined Ultrasonic Transducers

scholarly journals An Integrated Front-end Circuit Board for Air-Coupled CMUT Burst-Echo Imaging

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6128
Author(s):  
Lei Ye ◽  
Jian Li ◽  
Hui Zhang ◽  
Dongmei Liang ◽  
Zhuochen Wang
Keyword(s):  
Imaging System ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Ultrasonic Transducers ◽  
Circuit Board ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Front End ◽  
Field Programmable ◽  
Good Potential ◽  
Dc Bias

To conduct burst-echo imaging with air-coupled capacitive micromachined ultrasonic transducers (CMUTs) using the same elements in transmission and reception, this work proposes a dedicated and integrated front-end circuit board design to build an imaging system. To the best of the authors’ knowledge, this is the first air-coupled CMUT burst-echo imaging using the same elements in transmission and reception. The reported front-end circuit board, controlled by field programmable gate array (FPGA), consisted of four parts: an on-board pulser, a bias-tee, a T/R switch and an amplifier. Working with our 217 kHz 16-element air-coupled CMUT array under 100 V DC bias, the front-end circuit board and imaging system could achieve 22.94 dB signal-to-noise ratio (SNR) in burst-echo imaging in air, which could represent the surface morphology and the three-dimensional form factor of the target. In addition, the burst-echo imaging range of our air-coupled CMUT imaging system, which could work between 52 and 273 mm, was discussed. This work suggests good potential for ultrasound imaging and gesture recognition applications.

scholarly journals A Two-Dimensional CMUT Linear Array for Underwater Applications: Directivity Analysis and Design Optimization

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Wen Zhang ◽  
Hui Zhang ◽  
Shijiu Jin ◽  
Zhoumo Zeng
Keyword(s):  
Linear Array ◽  
Imaging System ◽  
Side Lobe ◽  
Ultrasonic Transducers ◽  
Two Dimensional ◽  
Mems Devices ◽  
Analysis And Design ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Influential Parameters

Capacitive micromachined ultrasonic transducers (CMUTs) are one of the promising MEMS devices. This paper proposed an integrated vibration membrane structure to design a two-dimensional CMUT linear array for underwater applications. The operation frequencies for different medium have been calculated and simulated, which are 2.5 MHz in air and 0.7 MHz in water. The directivity analyses for the CMUT cell, subarray, and linear array have been provided. According to the product theorems, the directivity function of the complex array is obtained using a combination of the directivity functions of certain simple structures. Results show that the directivity of a CMUT cell is weak due to the small size, but the directivity of the designed linear array is very strong. Influential parameters of the linear array have been discussed, including the cell numbers, the adjacent distance, and the operation medium. In order to further suppress the side lobe interference and improve the resolution and the imaging quality of the imaging system, several weighting methods are used for optimization and comparison. Satisfactory side lobe suppression results are obtained, which can meet the actual requirements.

scholarly journals Encapsulation of Capacitive Micromachined Ultrasonic Transducers (CMUTs) for the Acoustic Communication between Medical Implants

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 421
Author(s):  
Jorge Oevermann ◽  
Peter Weber ◽  
Steffen H. Tretbar
Keyword(s):  
Data Security ◽  
Ultrasonic Transducers ◽  
Surrounding Tissue ◽  
Center Frequency ◽  
Medical Implants ◽  
Research Groups ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Polyether Ether Ketone ◽  
High Bandwidth ◽  
Ether Ketone

The aim of this work was to extend conventional medical implants by the possibility of communication between them. For reasons of data security and transmitting distances, this communication should be realized using ultrasound, which is generated and detected by capacitive micromachined ultrasonic transducers (CMUTs). These offer the advantage of an inherent high bandwidth and a high integration capability. To protect the surrounding tissue, it has to be encapsulated. In contrast to previous results of other research groups dealing with the encapsulation of CMUTs, the goal here is to integrate the CMUT into the housing of a medical implant. In this work, CMUTs were designed and fabricated for a center frequency of 2 MHz in water and experimentally tested on their characteristics for operation behind layers of Polyether ether ketone (PEEK) and titanium, two typical materials for the housings of medical implants. It could be shown that with silicone as a coupling layer it is possible to operate a CMUT behind the housing of an implant. Although it changes the characteristics of the CMUT, the setup is found to be well suited for communication between two transducers over a distance of at least 8 cm.

Single-element Ultrasound Imaging System based on Mirror Scanning

2020 ◽  
Author(s):  
Seongwook Choi ◽  
Jin Young Kim ◽  
Hae Gyun Lim ◽  
Jin Woo Baik ◽  
Hyung Ham Kim ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
Imaging System ◽  
Single Element

scholarly journals Validation of Scolioscan Air-Portable Radiation-Free Three-Dimensional Ultrasound Imaging Assessment System for Scoliosis

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2858
Author(s):  
Kelly Ka-Lee Lai ◽  
Timothy Tin-Yan Lee ◽  
Michael Ka-Shing Lee ◽  
Joseph Chi-Ho Hui ◽  
Yong-Ping Zheng
Keyword(s):  
Ultrasound Imaging ◽  
Imaging System ◽  
Outcome Measurement ◽  
Three Dimensional ◽  
3D Ultrasound ◽  
Mean Difference ◽  
Assessment System ◽  
Absolute Difference ◽  
Data Sets ◽  
Low Profile

To diagnose scoliosis, the standing radiograph with Cobb’s method is the gold standard for clinical practice. Recently, three-dimensional (3D) ultrasound imaging, which is radiation-free and inexpensive, has been demonstrated to be reliable for the assessment of scoliosis and validated by several groups. A portable 3D ultrasound system for scoliosis assessment is very much demanded, as it can further extend its potential applications for scoliosis screening, diagnosis, monitoring, treatment outcome measurement, and progress prediction. The aim of this study was to investigate the reliability of a newly developed portable 3D ultrasound imaging system, Scolioscan Air, for scoliosis assessment using coronal images it generated. The system was comprised of a handheld probe and tablet PC linking with a USB cable, and the probe further included a palm-sized ultrasound module together with a low-profile optical spatial sensor. A plastic phantom with three different angle structures built-in was used to evaluate the accuracy of measurement by positioning in 10 different orientations. Then, 19 volunteers with scoliosis (13F and 6M; Age: 13.6 ± 3.2 years) with different severity of scoliosis were assessed. Each subject underwent scanning by a commercially available 3D ultrasound imaging system, Scolioscan, and the portable 3D ultrasound imaging system, with the same posture on the same date. The spinal process angles (SPA) were measured in the coronal images formed by both systems and compared with each other. The angle phantom measurement showed the measured angles well agreed with the designed values, 59.7 ± 2.9 vs. 60 degrees, 40.8 ± 1.9 vs. 40 degrees, and 20.9 ± 2.1 vs. 20 degrees. For the subject tests, results demonstrated that there was a very good agreement between the angles obtained by the two systems, with a strong correlation (R2 = 0.78) for the 29 curves measured. The absolute difference between the two data sets was 2.9 ± 1.8 degrees. In addition, there was a small mean difference of 1.2 degrees, and the differences were symmetrically distributed around the mean difference according to the Bland–Altman test. Scolioscan Air was sufficiently comparable to Scolioscan in scoliosis assessment, overcoming the space limitation of Scolioscan and thus providing wider applications. Further studies involving a larger number of subjects are worthwhile to demonstrate its potential clinical values for the management of scoliosis.

Capacitive micromachined ultrasonic transducers: Transmission evaluation with different membrane materials and dimensions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sudhanshu Tripathi ◽  
Rekha Agarwal ◽  
Rashmi Vashisth ◽  
Devraj Singh
Keyword(s):  
Resonant Frequency ◽  
Material Selection ◽  
Transmission Efficiency ◽  
Ultrasonic Transducers ◽  
Transduction Efficiency ◽  
Membrane Material ◽  
Structural Examination ◽  
Membrane Materials ◽  
Capacitive Micromachined Ultrasonic Transducers ◽  
Output Pressure

Abstract Capacitive micromachined ultrasonic transducers (CMUTs) are dominant in generating and receiving acoustic signals. CMUT transmission efficiency solely depends upon the membrane material utilized. This work presents the structural examination of receiving and transmitting characteristics of CMUT with divergent membrane materials, namely Silicon (Si), Silicon Nitride ( Si 3 N 4 {\mathrm{Si}_{3}}{\text{N}_{4}} ), Indium Phosphide (InP), Zinc Oxide (ZnO), and Polysilicon (Poly-Si). The analysis includes the membrane deflection, pull-in voltage, output pressure, resonant frequency and capacitance modification with variable DC voltage. It has been found that InP gives the pull-in voltage comparable to Si in the receiving mode and have more transduction efficiency in transmitting mode. Effect of dimensions of CMUT on pull-in voltage and resonant frequency are also discussed. The major contribution lies in the analytical and estimation study of CMUT for appropriate membrane material selection meant for transmission and reception in the field of pressure sensing application.

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