Novel Design of Low Noise Preamplifier for Medical Ultrasound Transducers

Amer, Mashhour Bani

doi:10.1007/s10916-009-9342-1

Cited by 4 publications

(3 citation statements)

References 5 publications

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“…We selected esomeprazole to manipulate the extracellular pH of NCI-H460 lung cancer cells, given its well-established efficacy and tolerability . It should be noted that the T 1 MR signal in both MnO 2 @BSA groups fluctuated simultaneously at several time points, which may result from uncontrollable factors of high magnetic resonance fields. , Notably, our biosafety results show that MnO 2 @BSA nanoparticles have high biocompatibility and therefore show potential for in vivo anti-acid monitoring applications.…”

Section: Discussionmentioning

confidence: 97%

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO₂@BSA Nanoparticles by Magnetic Resonance Imaging

Rong

Yao

Guo

et al. 2021

ACS Appl. Mater. Interfaces

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Microfluctuations in a pH gradient create a harsh microenvironment in tumors, leaving behind the most aggressive, invasive, and drug-resistant tumor cells. Directly visualizing the spatiotemporal distribution of pH variations and accurately quantifying the dynamic acid–base changes during cancer treatment are critical to estimate prognosis and to evaluate therapeutic efficacy. However, the quantification of subtle pH variations dynamically and noninvasively remains challenging. The purpose of this study is to determine and visualize dynamic acid–base changes in solid tumors during anti-acid treatments by magnetic resonance imaging (MRI) using pH-sensitive nanoparticles. We report the development of pH-sensitive nanoparticles, MnO2@BSA, that rapidly and strongly amplify the MR contrast signal in response to the extracellular acidic environment of solid tumors. The spatiotemporal distribution and dynamic fluctuations of pH heterogeneity in NCI-H460 lung tumors were observed with MnO2@BSA at different time points after an anti-acid treatment with esomeprazole, which directly interferes with the acidic microenvironment of the tumor. Imaging results were validated using a pH microsensor. MRI of pH-sensitive MnO2@BSA nanoparticles provided direct readouts of the kinetics of pH gradient fluctuations during esomeprazole treatment. A significant MR signal reduction was observed at the 48 h time point after treatment. The manipulated extracellular pH changes detected noninvasively by MRI coincided with the extracellular pH fluctuations measured with a pH microsensor (pH 6.12–6.63). Immunofluorescence and Western blot analyses confirmed the expression of V-ATPase in NCI-H460 lung cancer cells, which could be inhibited by esomeprazole, as detected by ELISA assay. Overall, these results demonstrate that MnO2@BSA MRI has great potential as a noninvasive tool to accurately monitor pH fluctuations, thereby paving the way for the dynamic detection of acidic microenvironments in vivo without the need for pH microsensors.

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Section: Discussionmentioning

confidence: 97%

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO₂@BSA Nanoparticles by Magnetic Resonance Imaging

Rong

Yao

Guo

et al. 2021

ACS Appl. Mater. Interfaces

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“…In recent literature, several designs of low noise preamplifiers (LNA) were proposed [10][11][12][13][14]. It is designed according the following criteria that ensure the LNA performance:…”

Section: The Design Methodology Of the Low Noise Preamplifiermentioning

confidence: 99%

Design of low-noise preamplifier for medical diagnostic system

Laurs

2011

ultra

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Experimental investigation of the developed eye tumors diagnostic system has revealed the tasks of system improvement, like reduction of the noise level of the preamplifier. The reliable solution is selection of analogue components of the preamplifier possessing as low noise level as available in the market of electronic components supply. Simultaneously, well known techniques of noise reduction should be used during the process design also. This paper discuses the design and development of the ultra-low noise preamplifier for medical applications. For the preamplifier schematic the principle of low frequency amplification with reduced the amplifier noise by n , where n is the number of amplifiers, is proposed. Using the final design of the preamplifier the noise factor value of 0.46 dB with gain of 48 dB and bandwidth of 2-35 MHz has been achieved.

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“…Additionally, the parasitic impedances of the ultrasound systems as well as cable loading critically affect the transducers’ sensitivity and bandwidth [3]. In order to achieve suitable signal quality for the VHF transducers, ultrasound transmitters need to generate higher voltage signals and the receiver’s dynamic range must also be large enough to amplify the low echo signals obtained from the transducers [4, 5]. Therefore, it is highly desirable that the performances of the ultrasound systems including protection circuits be optimized and improved.…”

Section: Introductionmentioning

confidence: 99%

Protection Circuits for Very High Frequency Ultrasound Systems

Choi

Shung

2014

J Med Syst

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The purpose of protection circuits in ultrasound applications is to block noise signals from the transmitter from reaching the transducer and also to prevent unwanted high voltage signals from reaching the receiver. The protection circuit using a resistor and diode pair is widely used due to its simple architecture, however, it may not be suitable for very high frequency (VHF) ultrasound transducer applications (>100 MHz) because of its limited bandwidth. Therefore, a protection circuit using MOSFET devices with unique structure is proposed in this paper. The performance of the designed protection circuit was compared with that of other traditional protection schemes. The performance characteristics measured were the insertion loss (IL), total harmonic distortion (THD) and transient response time (TRT). The new protection scheme offers the lowest IL (−1.0 dB), THD (−69.8 dB) and TRT (78 ns) at 120 MHz. The pulse-echo response using a 120 MHz LiNbO3 transducer with each protection circuit was measured to validate the feasibility of the protection circuits in VHF ultrasound applications. The sensitivity and bandwidth of the transducer using the new protection circuit improved by 252.1 and 50.9 %, respectively with respect to the protection circuit using a resistor and diode pair. These results demonstrated that the new protection circuit design minimizes the IL, THD and TRT for VHF ultrasound transducer applications.

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Novel Design of Low Noise Preamplifier for Medical Ultrasound Transducers

Cited by 4 publications

References 5 publications

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO₂@BSA Nanoparticles by Magnetic Resonance Imaging

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO₂@BSA Nanoparticles by Magnetic Resonance Imaging

Design of low-noise preamplifier for medical diagnostic system

Protection Circuits for Very High Frequency Ultrasound Systems

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Novel Design of Low Noise Preamplifier for Medical Ultrasound Transducers

Cited by 4 publications

References 5 publications

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO2@BSA Nanoparticles by Magnetic Resonance Imaging

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO2@BSA Nanoparticles by Magnetic Resonance Imaging

Design of low-noise preamplifier for medical diagnostic system

Protection Circuits for Very High Frequency Ultrasound Systems

Contact Info

Product

Resources

About

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO₂@BSA Nanoparticles by Magnetic Resonance Imaging

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO₂@BSA Nanoparticles by Magnetic Resonance Imaging