Head & Neck Oncology and Surgery, Netherlands Cancer Institute, Amsterdam, The Netherlands; Robotics and Mechatronics, Technical Medical Centre, University of Twente, Enschede, The Netherlands.
TIMC-IMAG Laboratory, University Grenoble Alpes & CNRS, Grenoble, France.
J Biomech. 2021 Jan 4;114:110147. doi: 10.1016/j.jbiomech.2020.110147. Epub 2020 Nov 25.
Tongue cancer treatment often results in impaired speech, swallowing, or mastication. Simulating the effect of treatments can help the patient and the treating physician to understand the effects and impact of the intervention. To simulate deformations of the tongue, identifying accurate mechanical properties of tissue is essential. However, not many succeeded in characterizing in-vivo tongue stiffness. Those who did, measured the tongue At Rest (AR), in which muscle tone subsides even if muscles are not willingly activated. We expected to find an absolute rest state in participants 'under General Anesthesia' (GA). We elaborated on previous work by measuring the mechanical behavior of the in-vivo tongue under aspiration using an improved volume-based method. Using this technique, 5 to 7 measurements were performed on 10 participants both AR and under GA. The obtained Pressure-Shape curves were first analyzed using the initial slope and its variations. Hereafter, an inverse Finite Element Analysis (FEA) was applied to identify the mechanical parameters using the Yeoh, Gent, and Ogden hyperelastic models. The measurements AR provided a mean Young's Modulus of 1638 Pa (min 1035 - max 2019) using the Yeoh constitutive model, which is in line with previous ex-vivo measurements. However, while hoping to find a rest state under GA, the tongue unexpectedly appeared to be approximately 2 to 2.5 times stiffer under GA than AR. Explanations for this were sought by examining drugs administered during GA, blood flow, perfusion, and upper airway reflexes, but neither of these explanations could be confirmed.
舌癌的治疗常导致言语、吞咽或咀嚼功能受损。模拟治疗效果可以帮助患者和治疗医生了解干预措施的效果和影响。为了模拟舌头的变形，识别组织的准确力学性能是至关重要的。然而，很少有人成功地对活体舌的刚度进行了特征描述。那些成功的人测量了舌在静止状态下的硬度（AR），即肌肉张力即使在肌肉没有主动收缩的情况下也会消退。我们期望在接受全身麻醉（GA）的参与者中找到一个绝对的静止状态。我们通过使用改进的基于体积的方法测量了在吸气过程中活体舌的力学行为，对以前的工作进行了阐述。使用这种技术，对 10 名参与者在 AR 和 GA 下进行了 5 到 7 次测量。首先使用初始斜率及其变化分析获得的压力-形状曲线。此后，应用逆有限元分析（FEA）来使用 Yeoh、Gent 和 Ogden 超弹性模型来识别力学参数。使用 Yeoh 本构模型，AR 测量提供了 1638 Pa 的平均杨氏模量（最小值 1035-最大值 2019），与以前的离体测量结果一致。然而，当我们希望在 GA 下找到一个静止状态时，出乎意料的是，GA 下的舌似乎比 AR 硬约 2 到 2.5 倍。通过检查 GA 期间使用的药物、血流、灌注和上气道反射来寻找对此的解释，但这些解释都无法得到证实。
