Department of Anesthesiology. University of Michigan Health System, 1H247 UH, SPC 5048 1500 East Medical Center Drive, Ann Arbor, MI 48109-5048, USA.
Anesth Analg. 2010 Sep;111(3):649-52. doi: 10.1213/ANE.0b013e3181e5ea7c. Epub 2010 Jun 25.
Anterior retraction of the tongue is used to enhance upper airway patency during pediatric fiberoptic intubation. This can be achieved by the use of Magill forceps as a tongue retractor, but lingual grip can become unsteady and traumatic. Our objective was to modify this instrument using computer-aided engineering for the purpose of stable tongue retraction.
We analyzed the geometry and mechanical properties of standard Magill forceps with a combination of analytical and empirical methods. This design was captured using computer-aided design techniques to obtain a 3-dimensional model allowing further geometric refinements and mathematical testing for rapid prototyping.
On the basis of our experimental findings we adjusted the design constraints to optimize the device for tongue retraction. Stereolithography prototyping was used to create a partially functional plastic model to further assess the functional and ergonomic effectiveness of the design changes. To reduce pressure on the tongue by regular Magill forceps, we incorporated (1) a larger diameter tip for better lingual tissue pressure profile, (2) a ratchet to stabilize such pressure, and (3) a soft molded tip with roughened surface to improve grip.
Computer-aided engineering can be used to redesign and prototype a popular instrument used in airway management. On a computational model, our modified Magill forceps demonstrated stable retraction forces, while maintaining the original geometry and versatility. Its application in humans and utility during pediatric fiberoptic intubation are yet to be studied.
在小儿纤维支气管镜插管中,舌体前拉可增加上气道通畅性。可使用 Magill 镊子作为舌牵开器来实现这一点,但舌夹持可能会变得不稳定和有创。我们的目的是使用计算机辅助工程对该器械进行修改,以实现稳定的舌体牵拉。
我们采用分析和经验相结合的方法对标准 Magill 镊子的几何形状和机械性能进行了分析。使用计算机辅助设计技术获取 3 维模型来捕获该设计,以进一步进行几何细化和数学测试,从而实现快速原型制作。
根据我们的实验结果,我们调整了设计约束条件,以使该装置最适合舌体牵拉。立体光刻原型制作用于创建部分功能的塑料模型,以进一步评估设计变更的功能和人体工程学效果。为了减少常规 Magill 镊子对舌体的压力,我们采用了(1)更大直径的尖端,以改善舌组织的压力分布;(2)棘轮以稳定这种压力;(3)具有粗糙表面的软模制尖端,以提高握持力。
计算机辅助工程可用于重新设计和制作气道管理中常用器械的原型。在计算模型中,我们修改后的 Magill 镊子展示了稳定的牵拉力,同时保持了原始的几何形状和多功能性。其在人体中的应用和在小儿纤维支气管镜插管中的实用性还有待研究。