Development of low-noise wideband receiver for intravascular ultrasound and photoacoustic imaging

A combined IVUS (Intravascular Ultrasound) and IVPA (Intravascular Photoacoustic) imaging system is beneficial for diagnosis of atherosclerosis, i.e., assessment of plaque vulnerability. The combined IVUS/IVPA imaging is performed by transmitting and/or receiving high frequency ultrasound (HFU) in the range of 20 MHz to 80 MHz or more. Since HFU transducers for the IVUS/IVPA imaging typically have a low sensitivity, the amplitude of received signals needs to be increased by at least 40 dB. This paper reports an analog frontend receiver developed for a combined IVUS/IVPA imaging system. The design goal was to achieve low-noise, wideband, high-gain, and high SNR characteristics by using off the shelf components. The developed receiver had the operating frequency range of more than 100 MHz, the gain flatness of less than 1 dB over 100 MHz, the dynamic range of 24 dB, and the total amplification gain range of 41 dB to 65 dB. In imaging test, it was measured that the signal-to-noise ratio of US and PA images were 36.5 dB and 34.5 dB, respectively, when the developed receiver was used. These values were superior to those by a commercial receiver, so that we believe that the developed receiver is suitable for a combined IVUS/IVPA imaging system.