Missel Paul J, Ma Yongting, McDonell Brian W, Shahmirzadi Danial, Abulon Dina Joy K, Sarangapani Ramesh
Data Science and Digital Solutions, Alcon Vision, LLC, Fort Worth, TX, USA.
Surgical Instrumentation, Alcon Research, Ltd., Lake Forest, CA, USA.
Transl Vis Sci Technol. 2020 Jul 30;9(8):46. doi: 10.1167/tvst.9.8.46. eCollection 2020 Jul.
To develop methods to simulate vitreous flow and traction during vitrectomy and qualify these methods using laboratory measurements.
Medium viscosity and phase treatment were adjusted to represent vitreous (Eulerian two-phase flow) or saline solution (single-phase Navier-Stokes flow). Retinal traction was approximated using a one-way fluid-structure interaction simulating cut vitreous volume coupled to a structural simulation of elastic stretching of a cylinder representing vitreous fibers entrained in the flow.
Simulated saline solution flow decreased, but vitreous flow increased with increasing cut rate, consistent with experimental trends observed for the 50/50 duty cycle mode. Traction simulations reproduced all trends in variation of traction force with changes in conditions. Simulations reproduced the majority of traction measurements within experimental error.
A scientific basis is provided for understanding how flow and traction vary with operational parameters. This model-based analysis serves as a "virtual lab" to determine optimal system settings to maximize flow efficiency while reducing traction.
The model provides a better understanding regarding how instrument settings can help control a vitrectomy procedure so that it can be made as efficient as possible (maximizing the rate of vitreous removal) while at the same time being made as safe as possible (minimizing retinal traction).
开发在玻璃体切割术中模拟玻璃体流动和牵引的方法，并通过实验室测量对这些方法进行验证。
调整介质粘度和相处理以代表玻璃体（欧拉两相流）或盐溶液（单相纳维-斯托克斯流）。使用单向流固相互作用来近似视网膜牵引，该相互作用模拟切割的玻璃体体积，并与代表流动中夹带的玻璃体纤维的圆柱体弹性拉伸的结构模拟相结合。
模拟的盐溶液流动随着切割速率的增加而降低，但玻璃体流动增加，这与在50/50占空比模式下观察到的实验趋势一致。牵引模拟再现了牵引力随条件变化的所有趋势。模拟在实验误差范围内再现了大部分牵引测量结果。
为理解流动和牵引如何随操作参数变化提供了科学依据。这种基于模型的分析作为一个“虚拟实验室”，用于确定最佳系统设置，以在降低牵引的同时最大化流动效率。
该模型有助于更好地理解仪器设置如何有助于控制玻璃体切割手术，从而使其尽可能高效（最大化玻璃体切除率），同时尽可能安全（最小化视网膜牵引）。
