A 100-V Withstanding Analog-Front-End for High-Resolution Intravascular Ultrasound Imaging

Intravascular Ultrasound ultrasonic imaging (IVUS) can microscopically image blood vessels and reveal tissue layers from within the blood vessel lumen. It has high tissue penetration ability for lesion classification and can image through blood. Compared to optical techniques, however, IVUS has lower resolution arising from low acoustic bandwidths which cannot resolve sharp edges. The presented 100-V withstanding Analog-Front-End (AFE) was developed to enable a high resolution, low cost IVUS system using a high-bandwidth focused polymer transducer with 40-MHz center frequency. The fabricated AFE interfaced with the transducer with minimal insertion loss, could withstand and duplex 100-V high voltage pulses and echo signal, and had a total signal chain gain of 9.8 dB. The AFE achieved a signal-to-noise ratio (SNR) of 20.1 dB including the insertion loss of the high-impedance transducer. AFE SNR was limited by input impedance required for high-voltage pulse clamping circuitry, but was sufficient for IVUS echo reception.Clinical Relevance— This work has the potential to enable much higher resolution, and potentially cheaper, IVUS imaging in blood vessels by integrating low-cost acoustic transducers with interface amplifiers directly on the catheter.