A 1.11 mm² IVUS SoC With -Range Plane Wave Transmit Beamforming at 40 MHz

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Ultrasound Technology

Background:

• Intravascular ultrasound (IVUS) imaging catheters are crucial for cardiovascular interventions.
• Miniaturization of IVUS devices for guidewires and microcatheters faces signal-to-noise ratio (SNR) challenges due to high-frequency requirements for adequate resolution.
• Integrated systems with transmit beamforming offer a solution to mitigate SNR limitations in miniaturized IVUS devices.

Purpose of the Study:

• To present the first practical, highly integrated system-on-a-chip (SoC) with plane wave transmit beamforming at 40 MHz for IVUS guidewires and microcatheters.
• To address the SNR limitations in miniaturized IVUS devices by developing an advanced beamforming SoC.

Main Methods:

• Developed a 20-channel ultrasound transmitter (Tx) and receiver (Rx) array integrated on a SoC, interfaced with a capacitive micromachined ultrasound transducer (CMUT) array.
• Implemented plane wave transmit beamforming using a voltage-controlled delay line (VCDL) for adjustable analog delays (0-10 ns) to generate steerable plane waves (+/-50 degrees) at 40 MHz.
• Fabricated the SoC using a 180-nm high-voltage (HV) CMOS process, achieving a compact active area (0.3 mm x 3.7 mm) and low power consumption (31.3 mW in receive mode).

Main Results:

• Demonstrated a highly integrated SoC capable of 40 MHz plane wave transmit beamforming for miniaturized IVUS applications.
• Achieved steerable plane wave generation with precise analog delay control via VCDL, enabling a steering range of +/-50 degrees.
• Validated the SoC's functionality and performance through acoustic characterization and imaging experiments, confirming its suitability for guidewire and microcatheter integration.

Conclusions:

• The presented SoC represents a significant advancement for intravascular ultrasound (IVUS) imaging, enabling enhanced resolution and SNR in miniaturized guidewire and microcatheter applications.
• The integrated plane wave beamforming technology overcomes key limitations of current miniaturized IVUS devices, paving the way for improved cardiovascular interventions.
• The compact size, low power consumption, and validated performance of the SoC demonstrate its practical feasibility for next-generation IVUS imaging systems.