Daoudi K, van den Berg P J, Rabot O, Kohl A, Tisserand S, Brands P, Steenbergen W
Opt Express. 2014 Oct 20;22(21):26365-74. doi: 10.1364/OE.22.026365.
Ultrasound and photoacoustics can be utilized as complementary imaging techniques to improve clinical diagnoses. Photoacoustics provides optical contrast and functional information while ultrasound provides structural and anatomical information. As of yet, photoacoustic imaging uses large and expensive systems, which limits their clinical application and makes the combination costly and impracticable. In this work we present and evaluate a compact and ergonomically designed handheld probe, connected to a portable ultrasound system for inexpensive, real-time dual-modality ultrasound/photoacoustic imaging. The probe integrates an ultrasound transducer array and a highly efficient diode stack laser emitting 130 ns pulses at 805 nm wavelength and a pulse energy of 0.56 mJ, with a high pulse repetition frequency of up to 10 kHz. The diodes are driven by a customized laser driver, which can be triggered externally with a high temporal stability necessary to synchronize the ultrasound detection and laser pulsing. The emitted beam is collimated with cylindrical micro-lenses and shaped using a diffractive optical element, delivering a homogenized rectangular light intensity distribution. The system performance was tested in vitro and in vivo by imaging a human finger joint.
超声和光声可作为互补成像技术用于改善临床诊断。光声提供光学对比度和功能信息，而超声提供结构和解剖学信息。到目前为止，光声成像使用的系统体积大且昂贵，这限制了它们的临床应用，并且使得两者结合成本高昂且不切实际。在这项工作中，我们展示并评估了一种紧凑且符合人体工程学设计的手持式探头，该探头连接到便携式超声系统，用于进行低成本的实时双模态超声/光声成像。该探头集成了一个超声换能器阵列以及一个高效二极管堆叠激光器，该激光器在805纳米波长处发射130纳秒脉冲，脉冲能量为0.56毫焦，具有高达10千赫的高脉冲重复频率。二极管由定制的激光驱动器驱动，该驱动器可通过外部触发，具有超声检测和激光脉冲同步所需的高时间稳定性。发射的光束通过柱面微透镜准直，并使用衍射光学元件进行整形，从而产生均匀的矩形光强分布。通过对人体手指关节成像，在体外和体内对该系统性能进行了测试。
