Multi Functional Optical Imaging Laboratory

Southern University of Science and Technology

In this study, we present the design,fabrication, and evaluation of a curved-array-based photoacousticimaging system designed for imaging vasculatures inside humanfinger joints with multispectral strategy.   The transducers have an average center frequencyof 6.6 MHz, and a mean bandwidth of 95%. The lateral and axialresolutions of the system are 110 μm and 800 μm, respectively,and the diameter of the active imaging is larger than 50 mm. We successfully captured the drug-induced cerebral bleeding spots inintact mouse brains, and recovered both morphology and oxygensaturation of the blood vessels in human finger joints. Conclusions:The PVDF transducer has a better performance in bandwidthcompared with commercial transducers. The curved design of thetransducer offers a better sensitivity and a higher axial resolutioncompared with the flat design. Significance: Based on thephantom, animal and human experiments, the proposed systemhas the potential to be used in clinical diagnosis of early-stagearthritis.[pdf]

Na Huang, Ming He, Haosheng Shi, Yuan Zhao, Man Lu, Xianbing Zou, Lei Yao, Huabei Jiang, and Lei Xi*, IEEE Transactions on Biomedical Engineering, 2017, DOI 10.1109/ TBME.2017.2758905.

In this study, we develop a new compound acoustic lensfabricated by integrating a concave polydimethylsiloxane (PDMS) lens and a convex epoxylens. Both theoretical simulations and experimental evaluations demonstrate that thecompound lens provides a larger directivity compared to single lenses made of PDMS, epoxy,and liquid. The measured acceptance angles of a 6-mm piezoelectric acoustic transducerequipped with the compound, epoxy, liquid, and PDMS lenses are 55°, 36°, 25°, and 20°,respectively. No deformation is observed in the off-center targets by using compound lens.However, serious deformation appears in the cases using single lenses.[pdf]

Shirui Yang#, Wei Qin#, Heng Guo, Tian Jin, Na Huang, Ming He, Lei Xi*, Biomedical Optics Express, 2017 8: 2756-2765.

The zebrafish, an ideal vertebrate for studying developmental biology and genetics,is increasingly being used to understand human diseases, due to its high similarity to the humangenome and its optical transparency during embryonic stages. Once the zebrafish has fullydeveloped, especially wild-type breeds, conventional optical imaging techniques havedifficulty in imaging the internal organs and structures with sufficient resolution andpenetration depth. Even with established mutant lines that remain transparent throughout theirlife cycle, it is still challenging for purely optical imaging modalities to visualize the organs ofjuvenile and adult zebrafish at a micro-scale spatial resolution. In this work, we developed anon-invasive three-dimensional photoacoustic imaging platform with an optimizedillumination pattern and a cylindrical-scanning-based data collection system to image entirezebrafish with micro-scale resolutions of 80 μm and 600 μm in the lateral and axial directions,respectively. In addition, we employed a multispectral strategy that utilized excitationwavelengths from 690 nm to 930 nm to statistically quantify the relative optical absorptionspectrum of major organs.[pdf]

Na Huang#, Heng Guo#, Weizhi Qi#, Zhiwei Zhang, Jian Rong, Zhen Yuan, Wei Ge, Huabei Jiang, Lei Xi*, Biomedical Optics Express, 2016, 7(9), 3543-3550.