- A Front-End ASIC with High-Voltage Transmit Switching and Receive Digitization for 3D Forward-Looking Intravascular Ultrasound Imaging
M. Tan; C. Chen; Z. Chen; J. Janjic; V. Daeichin; Z. Y. Chang; E. Noothout; G. van Soest; M. D. Verweij; N. de Jong; M. A. P. Pertijs;
IEEE Journal of Solid-State Circuits,
Volume 53, Issue 8, pp. 2284-2297, August 2018. DOI: 10.1109/JSSC.2018.2828826
Abstract: ...This paper presents an area- and power-efficient application-specified integrated circuit (ASIC) for 3-D forward-looking intravascular ultrasound imaging. The ASIC is intended to be mounted at the tip of a catheter, and has a circular active area with a diameter of 1.5 mm on the top of which a 2-D array of piezoelectric transducer elements is integrated. It requires only four micro-coaxial cables to interface 64 receive (RX) elements and 16 transmit (TX) elements with an imaging system. To do so, it routes high-voltage (HV) pulses generated by the system to selected TX elements using compact HV switch circuits, digitizes the resulting echo signal received by a selected RX element locally, and employs an energy-efficient load-modulation datalink to return the digitized echo signal to the system in a robust manner. A multi-functional command line provides the required sampling clock, configuration data, and supply voltage for the HV switches. The ASIC has been realized in a 0.18-μm HV CMOS technology and consumes only 9.1 mW. Electrical measurements show 28-V HV switching and RX digitization with a 16-MHz bandwidth and 53-dB dynamic range. Acoustical measurements demonstrate successful pulse transmission and reception. Finally, a 3-D ultrasound image of a three-needle phantom is generated to demonstrate the imaging capability.
- A 2D Ultrasound Transducer with Front-End ASIC and Low Cable Count for 3D Forward-Looking Intravascular Imaging: Performance and Characterization
J. Janjic; M. Tan; E. Noothout; C. Chen; Z. Chan; Z. Y. Chang; R. H. S. H. Beurskens; G. van Soest; A. F. W. van der Steen; M. D. Verweij; M. A. P. Pertijs; N. de Jong;
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control,
Volume 65, Issue 10, pp. 1832--1844, October 2018. Featured Cover Article. DOI: 10.1109/TUFFC.2018.2859824
Abstract: ...Intravascular ultrasound is an imaging modality used to visualize atherosclerosis from within the inner lumen of human arteries. Complex lesions like chronic total occlusions require forward-looking intravascular ultrasound (FL-IVUS), instead of the conventional side-looking geometry. Volumetric imaging can be achieved with 2D array transducers, which present major challenges in reducing cable count and device integration. In this work we present an 80-element lead zirconium titanate (PZT) matrix ultrasound transducer for FL-IVUS imaging with a front-end application-specific integrated circuit (ASIC) requiring only 4 cables. After investigating optimal transducer designs we fabricated the matrix transducer consisting of 16 transmit (TX) and 64 receive (RX) elements arranged on top of an ASIC having an outer diameter of 1.5 mm and a central hole of 0.5 mm for a guidewire. We modeled the transducer using finite element analysis and compared the simulation results to the values obtained through acoustic measurements. The TX elements showed uniform behavior with a center frequency of 14 MHz, a -3 dB bandwidth of 44 % and a transmit sensitivity of 0.4 kPa/V at 6 mm. The RX elements showed center frequency and bandwidth similar to the TX elements, with an estimated receive sensitivity of 3.7 μV/Pa. We successfully acquired a 3D FL image of three spherical reflectors in water using delay-and-sum beamforming and the coherence factor method. Full synthetic aperture acquisition can be achieved with frame rates on the order of 100 Hz. The acoustic characterization and the initial imaging results show the potential of the proposed transducer to achieve 3D FL-IVUS imaging.
- ASIC design for a single-cable 64-element ultrasound probe
D. van Willigen; J. Janjic; E. Kang; Z. Y. Chang; E. Noothout; M. Verweij; N. de Jong; M. Pertijs;
In Proc. IEEE International Ultrasonics Symposium (IUS),
IEEE, pp. 1-4, October 2018.
Abstract: ...This paper presents an ASIC (Application Specific Integrated Circuit) design for a catheter probe that interfaces 64 piezoelectric elements directly integrated on top of the ASIC to an imaging system using a single micro-coaxial cable. Each of the piezo elements can be used for both transmit (TX) and receive (RX), enabling full synthetic aperture imaging. A prototype has been realized with a 1.5mm diameter circular layout, intended for 3D intra-vascular ultrasound imaging. The functionality of this ASIC has been successfully demonstrated in a 3D imaging experiment. The design allows a single-element transducer to be replaced by a transdcuer array while using the same cable, making it a promising solution for 3D imaging with size constrained probes.
- Data collection system, in particular suitable for imaging of a distant object
D. M. van Willigen; M. A. P. Pertijs;
Patent, Dutch February 2018.
- A Front-End ASIC with High-Voltage Transmit Switching and Receive Digitization for Forward-Looking Intravascular Ultrasound
M. Tan; C. Chen; Z. Chen; J. Janjic; V. Daeichin; Z. Y. Chang; E. Noothout; G. van Soest; M. Verweij; N. de Jong; M. Pertijs;
In Proc. IEEE Custom Integrated Circuits Conference (CICC),
IEEE, pp. 1‒4, April 2017. DOI: 10.1109/cicc.2017.7993708
- A broadband PVDF-based hydrophone with integrated readout circuit for intravascular photoacoustic imaging
V. Daeichin; C. Chen; Q. Ding; M. Wu; R. Beurskens; G. Springeling; E. Noothout; M. D. Verweij; K. W.A. van Dongen; J. G. Bosch; A. F. W. van der Steen; N. de Jong; M. Pertijs; G. van Soest;
In Proc. SPIE Photonics West,
SPIE, February 2016. DOI: 10.1016/j.ultrasmedbio.2015.12.016
Abstract: ...Intravascular photoacoustic (IVPA) imaging can visualize the coronary atherosclerotic plaque composition on the basis of the optical absorption contrast. Most of the photoacoustic (PA) energy of human coronary plaque lipids was found to lie in the frequency band between 2 and 15 MHz requiring a very broadband transducer, especially if a combination with intravascular ultrasound is desired. We have developed a broadband polyvinylidene difluoride (PVDF) transducer (0.6 × 0.6 mm, 52 μm thick) with integrated electronics to match the low capacitance of such a small polyvinylidene difluoride element (<5 pF/mm2) with the high capacitive load of the long cable (∼100 pF/m). The new readout circuit provides an output voltage with a sensitivity of about 3.8 μV/Pa at 2.25 MHz. Its response is flat within 10 dB in the range 2 to 15 MHz. The root mean square (rms) output noise level is 259 μV over the entire bandwidth (1–20 MHz), resulting in a minimum detectable pressure of 30 Pa at 2.25 MHz.
- A single-cable PVDF transducer readout IC for intravascular photoacoustic imaging
C. Chen; V. Daeichin; Q. Ding; G. van Soest; G. Springeling; T. van der Steen; M. Pertijs; N. de Jong;
In Proc. IEEE International Ultrasonics Symposium (IUS),
IEEE, pp. 1‒4, October 2015. DOI: 10.1109/ultsym.2015.0142
Abstract: ...This paper presents a custom-designed single-cable readout IC for the reception of the broadband photoacoustic (PA) signal in intravascular photoacoustic (IVPA) imaging. The readout IC is intended for direct integration behind a broadband polyvinylidene fluoride (PVDF) transducer in an IVPA catheter tip to match the impedance between the small PVDF element and the connecting cable. The capability of the readout IC to work with a single cable that combines the output signal and the power supply ensures the mechanical flexibility of the IVPA catheter. Electrical measurements show that the readout IC provides a flat frequency response from 1 MHz to 20 MHz with a 6 mA external current supply. The acoustical measurements involving the readout IC and the PVDF transducer demonstrate a 60 dB dynamic range, a sensitivity of 3.8 μV/Pa at 2.25 MHz, and a broad receiving bandwidth from 2 MHz to 15 MHz.