Yang Guang, Amidi Eghbal, Nandy Sreyankar, Mostafa Atahar, Zhu Quing
Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Photoacoustics. 2018 Dec 7;13:66-75. doi: 10.1016/j.pacs.2018.12.001. eCollection 2019 Mar.
An optimized hand-held photoacoustic and ultrasound probe suitable for endo-cavity tumor subsurface imaging was designed and evaluated. Compared to previous designs, the prototype probe, consisting of four 1 mm multi-mode optical fibers attached with 1.5 mm diameter ball-shaped fiber tips sandwiched between a transvaginal ultrasound transducer and a custom-made sheath, demonstrated a higher light output and better beam homogeneity on tissue subsurface. The output power and fluence profile were simulated for different design parameters. A camera recorded fluence profiles through calibrated intralipid solution at various imaging depths. The light delivery efficiency was experimentally compared with and without the ball lenses, based on imaging of human colorectal cancer and imaging of a palmar vein proximal to the human wrist. The simulations and experiments demonstrated that ball-shaped fiber tip design can achieve homogeneous fluence distribution on tissue subsurface with acceptable light output efficiency, suggesting its clinical potential for endo-cavity imaging.
设计并评估了一种适用于腔内肿瘤表面下成像的优化手持式光声和超声探头。与先前的设计相比，该原型探头由四根1毫米的多模光纤组成，光纤末端连接着直径1.5毫米的球形光纤头，夹在经阴道超声换能器和定制护套之间，在组织表面下表现出更高的光输出和更好的光束均匀性。针对不同的设计参数模拟了输出功率和能量通量分布。通过校准的脂质乳剂溶液在不同成像深度下，用相机记录能量通量分布。基于对人类结直肠癌的成像以及对人手腕近端掌静脉的成像，通过实验比较了有无球透镜时光的传输效率。模拟和实验表明，球形光纤头设计能够在组织表面下实现均匀的能量通量分布，且光输出效率可接受，这表明其在腔内成像方面具有临床应用潜力。
