Photoacoustic sensing and imaging by sharing single data acquisition channel

摘要

As an emerging hybrid imaging modality, photoacoustic imaging has attracted intensive research interest in recent years in various applications, such as breast cancer detection, brain imaging, and intravascular imaging, which provides functional and molecular information. In a typical photoacoustic imaging system, laser intensity fluctuation needs to be monitored by a photodiode (PD) that can provide proper normalization for photoacoustic signals. Conventionally, at least two data acquisition channels are necessary to receive both photoacoustic signal and photodiode signal. In this paper, we propose a simple and efficient method to receive both photoacoustic and photodiode signals using single data acquisition channel, which gives lower system cost and faster system speed. After connecting the photodiode output and ultrasound transducer for hybrid signal acquisition, sharing channel can be achieved in two ways: Use a direct separation algorithm when received a PA signal with desirable signal-to-noise. Filters are exploited to keep low SNR PA signal immune from the photodiode signal and separate them from the receiving hybrid signal. 2D PA images based on the separated PA and PD signals will be illustrated to demonstrate their performance and efficiency. This method will be valuable especially when designing a PAT imaging system with multi-channel ultrasound array and data-acquisition card.