Xu Sheng, Ouellet Simon, Petel Oren E
Department of Mechanical and Aerospace Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada.
Defence Research and Development Canada Valcartier, 2459 Route de la Bravoure, Quebec, QC, G3J 1X5, Canada.
Ann Biomed Eng. 2025 May 5. doi: 10.1007/s10439-025-03716-z.
Headforms are commonly used as tools in the design and qualification of personal protective equipment. Deformable headforms, containing elastomeric brain models, provide a unique opportunity to directly measure the in situ intracranial strain from an impact; however, these physical models require significant refinement to ensure biofidelity. In the present work, the response and biofidelity of a deformable headform and brain model were investigated, comparing the influence of different boundary conditions on its response. More precisely, the presence or absence of a tentorium or a brainstem model were investigated, focusing on the resulting intracranial displacement and strain fields. The headforms were subjected to a series of linear impacts and deformations within the brain were tracked using embedded radiopaque markers and high-speed X-ray imaging. X-Ray Digital Image Correlation was used to calculate displacement and strain fields within the headform. The biofidelity of the displacement and strain fields within the headform design having both a tentorium and a brainstem were compared to Post-Mortem Human Subject (PMHS) data under identical impact conditions. The biofidelity was ranked using a CORA analysis to provide insight for future design refinements of the headform. The biofidelity ratings for displacement were highest in the frontal and occipital regions (good-excellent) and were worst in the insular region (marginal). Meanwhile, the strain biofidelity rating was best in the frontal (good) and cerebellum (good) regions and worst in the insular region (poor-marginal). This work addresses previous limitations in enhancing the biofidelity of closed headforms and offers opportunities for further improvement through the comparison to PMHS data.
头模通常用作个人防护装备设计和鉴定的工具。包含弹性体脑模型的可变形头模提供了一个独特的机会，可以直接测量撞击时的原位颅内应变；然而，这些物理模型需要进行重大改进以确保生物逼真度。在本研究中，研究了可变形头模和脑模型的响应及生物逼真度，比较了不同边界条件对其响应的影响。更确切地说，研究了小脑幕或脑干模型的有无，重点关注由此产生的颅内位移和应变场。对头模施加一系列线性撞击，并使用嵌入式不透射线标记和高速X射线成像跟踪脑内的变形。利用X射线数字图像相关技术计算头模内的位移和应变场。在相同撞击条件下，将具有小脑幕和脑干的头模设计中的位移和应变场的生物逼真度与尸检人体受试者（PMHS）数据进行了比较。使用CORA分析对头模的生物逼真度进行排名，以便为头模未来的设计改进提供参考。位移的生物逼真度评级在额叶和枕叶区域最高（良好-优秀），在岛叶区域最差（边缘）。同时，应变生物逼真度评级在额叶（良好）和小脑（良好）区域最佳，在岛叶区域最差（差-边缘）。这项工作解决了以往在提高闭合式头模生物逼真度方面的局限性，并通过与PMHS数据的比较提供了进一步改进的机会。
