dr. Chao Chen
Electronic Instrumentation (EI), Department of Microelectronics
PhD thesis (Apr 2018): Front-End ASICs for 3-D Ultrasound: From Beamforming to Digitization
Promotor: Michiel Pertijs, Nico de Jong
Expertise: ASICs for medical ultrasound and data convertersThemes: Smart Ultrasound
Chao Chen received the B.Sc. degree in micro-electronics from Tsinghua University, Beijing, China in 2010, and the M.Sc. (cum laude) and Ph.D. degree in micro-electronics from the Delft University of Technology, Delft, The Netherlands, in 2012 and 2018, respectively. His Ph.D. research topic was front-end application-specified integrated circuit (ASIC) design for 3-D medical ultrasound imaging.
Since 2017, Dr. Chen has been a Senior Analog IC designer with Butterfly Network Inc., Guilford, CT, USA, where he contributed to the development of next-generation ASICs for portable ultrasound. In 2021, he moved back to the Netherlands as a postdoctoral researcher at TU Delft, while continuing to hold a position as Consultant at Butterfly Network. His research interests include integrated circuits for medical imaging, low-power sensor interfaces, and high-resolution data converters.
Dr. Chen has authored and co-authored more than 30 publications and holds 3 US patents. He was a recipient of the Huygens Scholarship in 2011, the ISSCC STGA Award in 2013, the IEEE IUS Best Student Paper Award in 2017, and the Else Kooi Award in 2019. He was also a co-recipient of the A-SSCC 2017 Best Student Paper Award.
Miniature ultrasound probes for real-time 3D imaging and monitoring of cardiac interventions
This research project will enable the next generation of miniature ultrasound probes for real-time 3D transesophageal echocardiography, suitable for use in small children and newborns.
- A Pitch-Matched High-Frame-Rate Ultrasound Imaging ASIC for Catheter-Based 3D Probes
Yannick M. Hopf; Djalma Simoes dos Santos; Boudewine W. Ossenkoppele; Mehdi Soozande; Emile Noothout; Zu-Yao Chang; Chao Chen; Hendrik J. Vos; Johan G. Bosch; Martin D. Verweij; Nico de Jong; Michiel A. P. Pertijs;
IEEE Journal of Solid-State Circuits,
pp. 1--16, 2023. Early Access. DOI: 10.1109/JSSC.2023.3299749
Abstract: ...This article presents an application-specific integrated circuit (ASIC) for catheter-based 3-D ultrasound imaging probes. The pitch-matched design implements a comprehensive architecture with high-voltage (HV) transmitters, analog front ends, hybrid beamforming analog-to-digital converters (ADCs), and data transmission to the imaging system. To reduce the number of cables in the catheter while maintaining a small footprint per element, transmission (TX) beamforming is realized on the chip with a combination of a shift register (SR) and a row/column (R/C) approach. To explore an additional cable-count reduction in the receiver part of the design, a channel with a combination of time-division multiplexing (TDM), subarray beamforming, and multi-level pulse amplitude modulation (PAM) data transmission is also included. This achieves an 18-fold cable-count reduction and minimizes the power consumption in the catheter by a load modulation (LM) cable driver. It is further explored how common-mode interference can limit beamforming gain and a strategy to reduce its impact with local regulators is discussed. The chip was fabricated in TSMC 0.18-μm HV BCD technology and a 2-D PZT transducer matrix of 16 × 18 elements with a pitch of 160 μm and a center frequency of 6 MHz was manufactured on the chip. The system can generate all required TX patterns at up to 30 V, provides quick settling after the TX phase, and has an reception (RX) power consumption of only 1.12 mW/element. The functionality and operation of up to 1000 volumes/s have been demonstrated in electrical and acoustic imaging experiments.
- A Pitch-Matched Transceiver ASIC with Shared Hybrid Beamforming ADC for High-Frame-Rate 3D Intracardiac Echocardiography
Yannick M. Hopf; Boudewine W. Ossenkoppele; Mehdi Soozande; Emile Noothout; Zu-Yao Chang; Chao Chen; Hendrik J. Vos; Johan G. Bosch; Martin D. Verweij; Nico de Jong; Michiel A. P. Pertijs;
IEEE Journal of Solid-State Circuits,
Volume 57, Issue 11, pp. 3228--3242, November 2022. DOI: 10.1109/jssc.2022.3201758
Abstract: ...In this article, an application-specific integrated circuit (ASIC) for 3-D, high-frame-rate ultrasound imaging probes is presented. The design is the first to combine element-level, high-voltage (HV) transmitters and analog front-ends, subarray beamforming, and in-probe digitization in a scalable fashion for catheter-based probes. The integration challenge is met by a hybrid analog-to-digital converter (ADC), combining an efficient charge-sharing successive approximation register (SAR) first stage and a compact single-slope (SS) second stage. Application in large ultrasound imaging arrays is facilitated by directly interfacing the ADC with a charge-domain subarray beamformer, locally calibrating interstage gain errors and generating the SAR reference using a power-efficient local reference generator. Additional hardware-sharing between neighboring channels ultimately leads to the lowest reported area and power consumption across miniature ultrasound probe ADCs. A pitch-matched design is further enabled by an efficient split between the core circuitry and a periphery block, the latter including a datalink performing clock data recovery (CDR) and time-division multiplexing (TDM), which leads to a 12-fold total channel count reduction. A prototype of 8×9 elements was fabricated in a TSMC 0.18- μm HV BCD technology and a 2-D PZT transducer matrix with a pitch of 160μm , and a center frequency of 6 MHz was manufactured on the chip. The imaging device operates at up to 1000 volumes/s, generates 65-V transmit pulses, and has a receive power consumption of only 1.23 mW/element. The functionality has been demonstrated electrically as well as in acoustic and imaging experiments.
- Transceiver ASIC Design for High-Frame-Rate 3D Intracardiac Echocardiography
Yannick M. Hopf; Boudewine Ossenkoppele; Mehdi Soozande; Emile Noothout; Zu-Yao Chang; Chao Chen; Hendrik J. Vos; Johan G. Bosch; Martin D. Verweij; Nico de Jong; Michiel A. P. Pertijs;
In Proc. IEEE International Ultrasonics Symposium (IUS),
- Front-End ASICs for 3-D Ultrasound: From Beamforming to Digitization
PhD thesis, Delft University of Technology, April 2018.
- Energy-Efficient Self-Timed Zero-Crossing-Based Incremental Delta-Sigma ADC
MSc thesis, Delft University of Technology, November 2012.
Last updated: 7 Jul 2023