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 ex-vivo imaging of human colorectal cancer and in-vivo 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 in-vivo 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。与之前的设计相比，原型探头由四根 1 毫米多模光纤组成，这些光纤附有直径为 1.5 毫米的球形光纤尖端，夹在经阴道超声换能器和定制护套之间，具有更高的光输出和更好的光束组织表面下的均匀性。针对不同的设计参数模拟了输出功率和注量分布。相机通过校准的脂肪乳溶液在不同的成像深度记录注量分布。基于人类结肠直肠癌的离体成像和人类手腕近端的掌静脉的体内成像，对使用和不使用球透镜的光传输效率进行了实验比较。模拟和实验表明，球形光纤尖端设计可以在组织表面下实现均匀的注量分布，并具有可接受的光输出效率，表明其在体内腔内成像的临床潜力。