P5-A2-1 / ABSTRACT ID: 1568
DEVELOPMENT OF WIDE DYNAMIC RANGE RECEIVER FOR INTRAVASCULAR ULTRASOUND IMAGING Ju-Young
1 Moon ,
Junsu
2 Lee ,
and Jin Ho
2,3,4 Chang
1Institute
of Integrated Biotechnology, 2Department of Electronic Engineering, 3Department of Biomedical Engineering, 4Sogang Institutes of Advanced Technology, Sogang University, Seoul, Korea, Republic of
[email protected]
ABSTRACT
DESIGN & IMPLEMENTATION
Intravascular ultrasound (IVUS) imaging is typically limited by low sensitivity due to the small aperture of IVUS transducers and shallow imaging depth due to the frequency-dependent attenuation of ultrasound. A simple solution to these limitations is a wide dynamic range receiver. The developed receiver has a maximum amplification gain of 72 dB and a variable amplification gain of 48 dB at an operating frequency of 100 MHz. Also, it was confirmed that the developed signal receiver has SNR of more than 8.4 dB and CNR of 3.7 dB or more superior to commercial receiver.
RESULTS
• Required features of the analog frontend receiver – Low-noise – High amplification – Amplification gain flatness – High SNR – Wide dynamic range
Design goal
Measurement
Operating frequency
80 MHz
100 MHz
Minimum amplification gain
over 20 dB
over 25 dB
Amplification gain flatness
± 1 dB
± 0.9 dB
over 40 dB
48 dB
< Total amplification gain >
• SNR and CNR measurement [4-5] – Custom-made 52-MHz IVUS transducer Parameter
< Schematic of a wide dynamic range receiver >
Value
Center frequency
52 MHz
-6-dB bandwidth
62 %
Focused focal length
FR4
– Experiment arrangement
Signal 9 layers
< Transducer characteristics >
Layer stack Ground 9 layers Size
270 mm × 260 mm
Thickness
2.4 mm
Characteristic impedance
50 Ω
< Experiment arrangement for the performance evaluation > < photograph of the developed receiver >
– Wire phantom (4-25 μm golden-wire)
– SNR performance
– Challenges • Receiver using off-the-shelf components • Providing high amplification gain and wide dynamic amplification gain range simultaneously • Analog frontend receiver – key elements – High amplification gain, Wide dynamic range
< Developed receiver >
< Commercial receiver >
– Tissue-mimicking phantom (2-cyst, 2 mm, 3 mm) • mixture of agar power and 20- μm cellulose < Tissue-mimicking phantom >
< Wire phantom > Wire phantom (a), (b) Penetration depth
SNR (maximum)
Tissue mimicking phantom (c), (d) SNR (average)
This work was supported by International Collaborative R&D Program funded by the Ministry of Trade, Industry and Energy (MOTIE), Korea. (N01150049, Developing high frequency bandwidth [40~60MHz] high resolution image system and probe technology for diagnosing cardiovascular lesion)
REFERENCES
[1]
– Needs • High spatial resolution: tens μm resolution • Deep imaging depth: a few mm penetration depth – Overcomes • High attenuation: due to frequency dependent • Low sensitivity: due to aperture of transducers
Since the performance evaluation using tissuemimicking phantom was performed, in vitro experiments using vascular tissues will be performed.
ACKNOWLEDGMENT
3 mm
Printed Circuit Board Material
This paper presented the design, implementation, and performance evaluation of the developed receiver. The developed receiver has experimentally confirmed that the image quality is improved by compensating attenuation according to penetration depth by applying analog TGC. It is confirmed that the developed receiver can achieve a SNR of more than 5.9 dB and a CNR of more than 3.7 dB, compared with a commercial receiver. Based on the results, it is expected that high quality IVUS images can be obtained by applying the attenuation of the vascular tissue to analog-TGC module.
0.5 mm × 1.0 mm
Element size
• Implementation of the Wide dynamic range receiver
• Atherosclerosis – Usual cause of cardiovascular disease – Vulnerable plaque • Important contributory factor • Necessary accurate assessment • IVUS Imaging – Diagnosis of the atherosclerosis – Imaging of the vulnerable plaque • Thin fibrous cap, necrotic core
Parameter
Dynamic range
Keywords – intravascular ultrasound (IVUS) imaging; wide dynamic range; high frequency ultrasound; analog frontend receiver; timegain compensation (TGC)
INTRODUCTION
CONCLUSION & FUTURE WORK
• Electrical characteristics
• Design of the Wide dynamic range receiver – Overall functional block diagram [2-3]
Micro-Acoustic Functional Imaging Laboratory
CNR
Developed
Commercial
Developed
Commercial
Developed
Commercial
2 mm
56.0 dB
50.1 dB
43.4 dB
34.0 dB
15.4 dB
10.5 dB
3 mm
58.7 dB
51.9 dB
32.0 dB
22.0 dB
11.2 dB
7.5 dB
4 mm
47.5 dB
39.5 dB
5 mm
33.9 dB
26.2 dB
< Developed receiver >
< Commercial receiver >
[1] D. Vancraeynest, A. Pasquet, V. Rpelants, B. L. Gerber, and J.-L. J. Vanoverschelde, “Imaging the Vulnerable Plaque,” Journal of the American College of Cardiology, vol. 57, pp. 1961-1979, May 2011. [2] J.-Y. Moon, H. Kim, J. H. Song, J. Lee, and J. H. Chang, “Development of low-noise wideband receiver for intravascular ultrasound and photoacoustic imaging,” 2013 IEEE International Ultrasonics Symposium, pp. 1575-1578, July 2013. [3] J.-Y. Moon, J. Lee, and J. H. Chang, “Electrical impedance matching networks based on filter structures for high frequency ultrasound transducers,” Sensors and Actuators A: Physical, vol. 251, pp. 225-233, November 2016. [4] J. Lee, J. Jang, and J. H. Chang, “Oblong-shaped-focused transducers for intravascular ultrasound imaging,” IEEE Trans. Biomed. Eng., vol. 64, pp. 671-680, March 2017. [5] D. Y. Lee, Y. Yoo, T. K. Song, and J. H. Chang, “Adaptive dynamic quadrature demodulation with autoregressive spectral estimation in ultrasound imaging,” Biomed. Signal Process. Control, vol. 7, pp371-398, July 2012.
