Feng Ting, Li Qiaochu, Zhang Cheng, Xu Guan, Guo L Jay, Yuan Jie, Wang Xueding
Opt Express. 2016 Aug 22;24(17):19853-62. doi: 10.1364/OE.24.019853.
Photoacoustic spectrum analysis (PASA) has been demonstrated as a new method for quantitative tissue imaging and characterization. The ability of PASA in evaluating micro-size tissue features was limited by the bandwidth of detectors for photoacoustic (PA) signal acquisition. We improve upon such a limit, and report on developments of PASA facilitated by an optical ultrasonic detector based on micro-ring resonator. The detector's broad and flat frequency response significantly improves the performance of PASA and extents its characterization capability from the tissue level to cellular level. The performance of the system in characterizing cellular level (a few microns) stochastic objects was first shown via a study on size-controlled optically absorbing phantoms. As a further demonstration of PASA's potential clinical application, it was employed to characterize the morphological changes of red blood cells (RBCs) from a biconcave shape to a spherical shape as a result of aging. This work demonstrates that PASA equipped with the micro-ring ultrasonic detectors is an effective technique in characterizing cellular-level micro-features of biological samples.
光声光谱分析（PASA）已被证明是一种用于定量组织成像和表征的新方法。PASA在评估微小尺寸组织特征方面的能力受到用于光声（PA）信号采集的探测器带宽的限制。我们改进了这一限制，并报告了基于微环谐振器的光学超声探测器推动的PASA的发展情况。该探测器宽广且平坦的频率响应显著提高了PASA的性能，并将其表征能力从组织水平扩展到细胞水平。通过对尺寸可控的光吸收体模的研究，首次展示了该系统在表征细胞水平（几微米）随机物体方面的性能。作为PASA潜在临床应用的进一步证明，它被用于表征红细胞（RBC）因老化而从双凹形变为球形的形态变化。这项工作表明，配备微环超声探测器的PASA是表征生物样品细胞水平微观特征的有效技术。
