在光声显微成像中,系统的探测灵敏度是决定成像质量和探测深度的关键因素,也将进一步影响光声成像在生物医学领域中的应用范围。通过将微型放大芯片集成至换能器单元,实现信号的前置放大和输出阻抗的匹配,提高了探测灵敏度和信噪比;基于制备的原型换能器搭建了光声显微成像系统,并通过仿体和大鼠耳部血管的三维成像实验,验证了该系统进行高灵敏光声显微成像的可行性。实验结果表明:基于集成放大芯片换能器的光声显微成像技术可使光声信号的信噪比提升10 dB以上,具有应用于微弱生理、病理变化检测和定量分析的潜力。

In photoacoustic microscopy (PAM), detection sensitivity is an important factor for determining imaging quality and depth, which can affect photoacoustic imaging applications in biomedical engineering. To improve the detection sensitivity and signal-to-noise ratio (SNR), a miniature amplifier was integrated close to an ultrasound transducer for front-end signal amplification and output impedance matching. An optical resolution PAM was developed based on the fabricated prototype transducer to perform 3D imaging of phantoms and small vessels of the mouse ear. Experimental results show that the SNR is improved by over 10 dB. The proposed PAM has the potential to be used for monitoring and quantitatively analyzing weak physiological changes.