Rossi Tommaso, Querzoli Giorgio, Angelini Giampiero, Malvasi Carlo, Iossa Mario, Placentino Luca, Ripandelli Guido
*Eye Hospital of Rome, Rome, Italy; †Department of Civil and Environmental Engineering and Architecture, University of Cagliari, Caligari, Italy; ‡Optikon 2000 Inc., Rome, Italy; and §G.B. Bietti Foundation for Study and Research in Ophthalmology Research Hospital, Rome, Italy.
Retina. 2014 Mar;34(3):558-67. doi: 10.1097/IAE.0b013e3182a0e628.
To characterize the fluidics of vitreous cutter port in response to aspiration and blade motion using particle image velocimetry techniques. Diverse surgical scenarios and fluid characteristics were replicated.
The 23-gauge vitreous cutters were immersed in seeded Balanced Salt Solution (BSS) (Alcon, Forth Worth, TX) or egg albumen, and high-speed video was recorded. Fluid velocity, kinetic energy (KE), and acceleration generated by Venturi and peristaltic pumps were measured in aspiration only (200 and 300 mmHg), low-speed vitrectomy (1,600 cuts per minute; 200 mmHg vacuum), and high-speed vitrectomy (3,000 cuts per minute; 300 mmHg vacuum) modes.
The Venturi pump generated significantly higher KE than peristaltic pump in BSS (P < 0.0001 for each pair), and aspiration only yielded significantly higher KE. Cutting activation generated significant acceleration (P < 0.001), and the peristaltic pump produced higher positive and negative acceleration peaks (P < 0.001) than the Venturi pump. In egg albumen, the peristaltic pump generated significantly more KE than the Venturi pump (P < 0.001) and perturbed a much wider area. Acceleration was higher for the peristaltic pump in low-speed mode (P < 0.001), whereas in high-speed modality, the Venturi pump produced the highest acceleration peaks (P < 0.001).
Pump type and blade motion largely influence velocity, KE, and acceleration. In BSS, the Venturi pump induces higher KE and acceleration, although perturbing fluid less diffusely. In egg albumen, the peristaltic pump perturbed a much wider area and induced a higher KE and acceleration than the Venturi pump, even more so at lower cut rates. As a conclusion, particle image velocimetry allowed precise characterization of fluid velocity in response to cutter activation, suggesting a pragmatic approach to surgical scenarios.
使用粒子图像测速技术来描述玻璃体切割器端口在抽吸和刀片运动时的流体力学特性。模拟了不同的手术场景和流体特性。
将23号玻璃体切割器浸入含有示踪粒子的平衡盐溶液(BSS)(爱尔康公司,得克萨斯州沃思堡)或蛋清中,并记录高速视频。测量了仅抽吸(200和300mmHg)、低速玻璃体切除术(每分钟1600次切割;200mmHg真空度)和高速玻璃体切除术(每分钟3000次切割;300mmHg真空度)模式下,文丘里泵和蠕动泵产生的流体速度、动能(KE)和加速度。
在BSS中,文丘里泵产生的KE显著高于蠕动泵(每对比较P<0.0001),且仅抽吸时产生的KE显著更高。切割启动产生显著加速度(P<0.001),蠕动泵产生的正负加速度峰值高于文丘里泵(P<0.001)。在蛋清中,蠕动泵产生的KE显著高于文丘里泵(P<0.001),且扰动的区域更宽。蠕动泵在低速模式下加速度更高(P<0.001),而在高速模式下,文丘里泵产生的加速度峰值最高(P<0.001)。
泵的类型和刀片运动在很大程度上影响速度、KE和加速度。在BSS中,文丘里泵诱导产生更高的KE和加速度,尽管对流体的扰动扩散范围较小。在蛋清中,蠕动泵扰动的区域更宽,诱导产生的KE和加速度高于文丘里泵,在较低切割速率下更是如此。总之,粒子图像测速技术能够精确描述切割器启动时的流体速度,为手术场景提供了一种实用的方法。