Fully integrated 2D CMUT ring arrays for endoscopic ultrasound

Azadeh Moini, Amin Nikoozadeh, Jung Woo Choe, Chienliu Chang, Douglas N. Stephens, David Sahn, Pierre T. Khuri-Yakub

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

Ultrasound has become more prevalent as a medical tool for real-time volumetric imaging. Sparse 2D CMUT ring arrays generate high resolution volumetric images with fewer elements than a fully populated 2D array, allow for integration with electronics in an endoscope form factor, and provide a central lumen for simultaneous use of additional diagnostic and therapeutic tools, such as HIFU or photoacoustic fibers, without increasing the overall package size. We have previously fabricated QuadRing capacitive micromachined ultrasound transducers (CMUTs). Each of the four independent, concentric rings in the array contains 128 elements and operates at a different center frequency. In this work, we use one of the four concentric rings at 4MHz for a fully integrated endoscope assembly. Custom charge-amplifier ASICs were used in these assemblies rather than transimpedance amplifiers, reducing the noise figure of the system. The CMUT arrays are flip chip bonded to a custom 8-leg flexible PCB (flex) that provides electrical connections between the CMUT array, ASICs, and Verasonics imaging system. The flip chip bonded assembly is integrated with a custom 3D printed tip that encases and mechanically supports the assembly, and provides a convenient built-in reference for the passivation layer. Additionally, one flex version flips the CMUT bias, grounding the top electrode without additional circuitry by level-shifting the IC supplies. This feature is particularly desirable for clinical applications, as it shields the patient from the CMUT bias voltage. This new 128-element forward-facing CMUT endoscope has been used for real-time 3D imaging on the bench and expands the toolkit beyond previous work in several ways: high quality images are obtained using a relatively sparse array; new ASICs have shown improvements in SNR; and the array size has enabled use of new 3D-printed, highly customizable assembly tools. We have validated operation with a grounded CMUT top electrode, a critical step towards clinical use. Furthermore, a large lumen increases the breadth of tools that can be used in conjunction with the imaging array.

Original languageEnglish (US)
Title of host publication2016 IEEE International Ultrasonics Symposium, IUS 2016
PublisherIEEE Computer Society
Volume2016-November
ISBN (Electronic)9781467398978
DOIs
StatePublished - Nov 1 2016
Event2016 IEEE International Ultrasonics Symposium, IUS 2016 - Tours, France
Duration: Sep 18 2016Sep 21 2016

Other

Other2016 IEEE International Ultrasonics Symposium, IUS 2016
CountryFrance
CityTours
Period9/18/169/21/16

Fingerprint

transducers
rings
endoscopes
application specific integrated circuits
assembly
lumens
polychlorinated biphenyls
amplifiers
chips
electrodes
assemblies
seats
passivity
form factors
fibers
high resolution
electric potential
electronics

Keywords

  • CMUT
  • endoscopic
  • forward-looking
  • real-time
  • ultrasound capacitive micromachined ultrasonic transducer
  • volumetric

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

Cite this

Moini, A., Nikoozadeh, A., Choe, J. W., Chang, C., Stephens, D. N., Sahn, D., & Khuri-Yakub, P. T. (2016). Fully integrated 2D CMUT ring arrays for endoscopic ultrasound. In 2016 IEEE International Ultrasonics Symposium, IUS 2016 (Vol. 2016-November). [7728542] IEEE Computer Society. https://doi.org/10.1109/ULTSYM.2016.7728542

Fully integrated 2D CMUT ring arrays for endoscopic ultrasound. / Moini, Azadeh; Nikoozadeh, Amin; Choe, Jung Woo; Chang, Chienliu; Stephens, Douglas N.; Sahn, David; Khuri-Yakub, Pierre T.

2016 IEEE International Ultrasonics Symposium, IUS 2016. Vol. 2016-November IEEE Computer Society, 2016. 7728542.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Moini, A, Nikoozadeh, A, Choe, JW, Chang, C, Stephens, DN, Sahn, D & Khuri-Yakub, PT 2016, Fully integrated 2D CMUT ring arrays for endoscopic ultrasound. in 2016 IEEE International Ultrasonics Symposium, IUS 2016. vol. 2016-November, 7728542, IEEE Computer Society, 2016 IEEE International Ultrasonics Symposium, IUS 2016, Tours, France, 9/18/16. https://doi.org/10.1109/ULTSYM.2016.7728542
Moini A, Nikoozadeh A, Choe JW, Chang C, Stephens DN, Sahn D et al. Fully integrated 2D CMUT ring arrays for endoscopic ultrasound. In 2016 IEEE International Ultrasonics Symposium, IUS 2016. Vol. 2016-November. IEEE Computer Society. 2016. 7728542 https://doi.org/10.1109/ULTSYM.2016.7728542
Moini, Azadeh ; Nikoozadeh, Amin ; Choe, Jung Woo ; Chang, Chienliu ; Stephens, Douglas N. ; Sahn, David ; Khuri-Yakub, Pierre T. / Fully integrated 2D CMUT ring arrays for endoscopic ultrasound. 2016 IEEE International Ultrasonics Symposium, IUS 2016. Vol. 2016-November IEEE Computer Society, 2016.
@inproceedings{54a9e4720fd649ebb66205237dff3c6b,
title = "Fully integrated 2D CMUT ring arrays for endoscopic ultrasound",
abstract = "Ultrasound has become more prevalent as a medical tool for real-time volumetric imaging. Sparse 2D CMUT ring arrays generate high resolution volumetric images with fewer elements than a fully populated 2D array, allow for integration with electronics in an endoscope form factor, and provide a central lumen for simultaneous use of additional diagnostic and therapeutic tools, such as HIFU or photoacoustic fibers, without increasing the overall package size. We have previously fabricated QuadRing capacitive micromachined ultrasound transducers (CMUTs). Each of the four independent, concentric rings in the array contains 128 elements and operates at a different center frequency. In this work, we use one of the four concentric rings at 4MHz for a fully integrated endoscope assembly. Custom charge-amplifier ASICs were used in these assemblies rather than transimpedance amplifiers, reducing the noise figure of the system. The CMUT arrays are flip chip bonded to a custom 8-leg flexible PCB (flex) that provides electrical connections between the CMUT array, ASICs, and Verasonics imaging system. The flip chip bonded assembly is integrated with a custom 3D printed tip that encases and mechanically supports the assembly, and provides a convenient built-in reference for the passivation layer. Additionally, one flex version flips the CMUT bias, grounding the top electrode without additional circuitry by level-shifting the IC supplies. This feature is particularly desirable for clinical applications, as it shields the patient from the CMUT bias voltage. This new 128-element forward-facing CMUT endoscope has been used for real-time 3D imaging on the bench and expands the toolkit beyond previous work in several ways: high quality images are obtained using a relatively sparse array; new ASICs have shown improvements in SNR; and the array size has enabled use of new 3D-printed, highly customizable assembly tools. We have validated operation with a grounded CMUT top electrode, a critical step towards clinical use. Furthermore, a large lumen increases the breadth of tools that can be used in conjunction with the imaging array.",
keywords = "CMUT, endoscopic, forward-looking, real-time, ultrasound capacitive micromachined ultrasonic transducer, volumetric",
author = "Azadeh Moini and Amin Nikoozadeh and Choe, {Jung Woo} and Chienliu Chang and Stephens, {Douglas N.} and David Sahn and Khuri-Yakub, {Pierre T.}",
year = "2016",
month = "11",
day = "1",
doi = "10.1109/ULTSYM.2016.7728542",
language = "English (US)",
volume = "2016-November",
booktitle = "2016 IEEE International Ultrasonics Symposium, IUS 2016",
publisher = "IEEE Computer Society",

}

TY - GEN

T1 - Fully integrated 2D CMUT ring arrays for endoscopic ultrasound

AU - Moini, Azadeh

AU - Nikoozadeh, Amin

AU - Choe, Jung Woo

AU - Chang, Chienliu

AU - Stephens, Douglas N.

AU - Sahn, David

AU - Khuri-Yakub, Pierre T.

PY - 2016/11/1

Y1 - 2016/11/1

N2 - Ultrasound has become more prevalent as a medical tool for real-time volumetric imaging. Sparse 2D CMUT ring arrays generate high resolution volumetric images with fewer elements than a fully populated 2D array, allow for integration with electronics in an endoscope form factor, and provide a central lumen for simultaneous use of additional diagnostic and therapeutic tools, such as HIFU or photoacoustic fibers, without increasing the overall package size. We have previously fabricated QuadRing capacitive micromachined ultrasound transducers (CMUTs). Each of the four independent, concentric rings in the array contains 128 elements and operates at a different center frequency. In this work, we use one of the four concentric rings at 4MHz for a fully integrated endoscope assembly. Custom charge-amplifier ASICs were used in these assemblies rather than transimpedance amplifiers, reducing the noise figure of the system. The CMUT arrays are flip chip bonded to a custom 8-leg flexible PCB (flex) that provides electrical connections between the CMUT array, ASICs, and Verasonics imaging system. The flip chip bonded assembly is integrated with a custom 3D printed tip that encases and mechanically supports the assembly, and provides a convenient built-in reference for the passivation layer. Additionally, one flex version flips the CMUT bias, grounding the top electrode without additional circuitry by level-shifting the IC supplies. This feature is particularly desirable for clinical applications, as it shields the patient from the CMUT bias voltage. This new 128-element forward-facing CMUT endoscope has been used for real-time 3D imaging on the bench and expands the toolkit beyond previous work in several ways: high quality images are obtained using a relatively sparse array; new ASICs have shown improvements in SNR; and the array size has enabled use of new 3D-printed, highly customizable assembly tools. We have validated operation with a grounded CMUT top electrode, a critical step towards clinical use. Furthermore, a large lumen increases the breadth of tools that can be used in conjunction with the imaging array.

AB - Ultrasound has become more prevalent as a medical tool for real-time volumetric imaging. Sparse 2D CMUT ring arrays generate high resolution volumetric images with fewer elements than a fully populated 2D array, allow for integration with electronics in an endoscope form factor, and provide a central lumen for simultaneous use of additional diagnostic and therapeutic tools, such as HIFU or photoacoustic fibers, without increasing the overall package size. We have previously fabricated QuadRing capacitive micromachined ultrasound transducers (CMUTs). Each of the four independent, concentric rings in the array contains 128 elements and operates at a different center frequency. In this work, we use one of the four concentric rings at 4MHz for a fully integrated endoscope assembly. Custom charge-amplifier ASICs were used in these assemblies rather than transimpedance amplifiers, reducing the noise figure of the system. The CMUT arrays are flip chip bonded to a custom 8-leg flexible PCB (flex) that provides electrical connections between the CMUT array, ASICs, and Verasonics imaging system. The flip chip bonded assembly is integrated with a custom 3D printed tip that encases and mechanically supports the assembly, and provides a convenient built-in reference for the passivation layer. Additionally, one flex version flips the CMUT bias, grounding the top electrode without additional circuitry by level-shifting the IC supplies. This feature is particularly desirable for clinical applications, as it shields the patient from the CMUT bias voltage. This new 128-element forward-facing CMUT endoscope has been used for real-time 3D imaging on the bench and expands the toolkit beyond previous work in several ways: high quality images are obtained using a relatively sparse array; new ASICs have shown improvements in SNR; and the array size has enabled use of new 3D-printed, highly customizable assembly tools. We have validated operation with a grounded CMUT top electrode, a critical step towards clinical use. Furthermore, a large lumen increases the breadth of tools that can be used in conjunction with the imaging array.

KW - CMUT

KW - endoscopic

KW - forward-looking

KW - real-time

KW - ultrasound capacitive micromachined ultrasonic transducer

KW - volumetric

UR - http://www.scopus.com/inward/record.url?scp=84996490200&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84996490200&partnerID=8YFLogxK

U2 - 10.1109/ULTSYM.2016.7728542

DO - 10.1109/ULTSYM.2016.7728542

M3 - Conference contribution

AN - SCOPUS:84996490200

VL - 2016-November

BT - 2016 IEEE International Ultrasonics Symposium, IUS 2016

PB - IEEE Computer Society

ER -