A sidelobe suppressing near-field beamforming approach for ultrasound array imaging

Journal of Healthcare Engineering

Jeong²,

Kim

2017

In medical ultrasound transducers, the transmission mode (pass-through) approach has been used to estimate the characteristics of the acoustic lens. However, it is difficult to measure the acoustic lens properties with high precision because of human, systemic, or mechanical measurement errors. In this paper, we propose a low-cost estimation instrument for acoustic lens properties connected with a customized database. In the instrument, three-axis and one-axis transmitting and material fixtures accurately align the transmitting and receiving transducers separately. Through the developed instrument, we obtained a precise standard deviation of the attenuation coefficient and velocity of the acoustic lens material of 0.05 dB/cm and 2.62 m/s, respectively. Additionally, the simultaneous alignment between the fixtures is controllable with developed programs, thus generating very accurate information of the acoustic lens about the testing ultrasound transducer. In our instrument, the database could support users in managing the result data efficiently. User programs developed using LabVIEW provide the capability to obtain precise values of the attenuation coefficient and velocity, which represent the fundamental material characteristics of the acoustic lens of the medical ultrasound transducers. The developed review program of the customized database can also search the acoustic lens information and store the experimental results.

Section: Introductionmentioning

confidence: 99%

Development of an Estimation Instrument of Acoustic Lens Properties for Medical Ultrasound Transducers

Journal of Healthcare Engineering

Jeong²,

Kim

2017

“…The expander and limiter can reduce signal ring-down and block high voltage pulses, respectively [12]. The power amplifier, which is controlled by the digital-to-analog converter (DAC) and analog-to-digital converter (ADC), is used to achieve better energy transfer in electromechanical components, such as transducers [13]. The echo signals generated from the transducer are sent via the ADC to the display [11,14].…”

Section: Introductionmentioning

confidence: 99%

Wide Bandwidth Class-S Power Amplifiers for Ultrasonic Devices

You

2020

Sensors

Wide bandwidth ultrasonic devices are a necessity in high-resolution ultrasonic systems. Therefore, constant output voltages need to be produced across the wide bandwidths of a power amplifier. We present the first design of a wide bandwidth class-S power amplifier for ultrasonic devices. The −6 dB bandwidth of the developed class-S power amplifier was measured at 125.07% at 20 MHz, thus, offering a wide bandwidth for ultrasonic devices. Pulse-echo measurement is a performance measurement method used to evaluate the performance of ultrasonic transducers, components, or systems. The pulse-echo signals were obtained using an ultrasonic transducer with designed power amplifiers. In the pulse-echo measurements, time and frequency analyses were conducted to evaluate the bandwidth flatness of the power amplifiers. The frequency range of the ultrasonic transducer was measured and compared when using the developed class-S and commercial class-A power amplifiers with the same output voltages. The class-S power amplifiers had a relatively flat bandwidth (109.7 mV at 17 MHz, 112.0 mV at 20 MHz, and 109.5 mV at 23 MHz). When the commercial class-A power amplifier was evaluated under the same conditions, an uneven bandwidth was recorded (110.6 mV at 17 MHz, 111.5 mV at 20 MHz, and 85.0 mV at 23 MHz). Thus, we demonstrated that the designed class-S power amplifiers could prove useful for ultrasonic devices with a wide frequency range.

“…Ultrasound is used in a variety of applications such as medical diagnostics and therapy, non-destructive testing, and sound navigation and range [1][2][3]. In particular, medical ultrasound imaging is a non-invasive and inexpensive technique compared to X-ray, computed tomography, and positron emission tomography [4,5]. Owing to the developments in the semiconductor industry, medical ultrasound imaging instrumentation has been widely used for cost-effective diagnostic solutions [6,7].…”

Section: Introductionmentioning

confidence: 99%

Development of modified RSA algorithm using fixed mersenne prime numbers for medical ultrasound imaging instrumentation

Shin

Yoo

Computer Assisted Surgery

2019

Purpose: Encryption of patient information has become an important issue in medical ultrasound instrumentation to secure information when images are accessed off-site. The proposed algorithm is used to encrypt private medical images and transfer the encrypted images to improve the encryption capability and elapsed time. Materials and methods: We generate a public key using three prime numbers, including a fixed Mersenne prime number, in the modified Rivest-Shamir-Adelman (RSA) algorithm to compare the encryption capability. We calculated and compared the elapsed time using the modified RSA algorithm with a breast phantom in the medical ultrasound imaging instrumentation. Results: The encryption capability is improved because the elapsed time when using three prime numbers is longer (1.2337 s) than that when using two prime numbers (1.0712 s). However, the elapsed time using fixed Mersenne prime numbers (0.8360 s) is a similar to that using two prime numbers (0.8389 s). Conclusions: Our proposed cryptographic algorithm provides improved encryption in medical ultrasound imaging compared to algorithms that use two prime numbers that are not Mersenne prime numbers, while transmitting images with adequate elapsed times.