Numerical simulation of labour and associated foetal brain loading

在阴道分娩过程中，胎儿的头部会随着产道的几何约束而变形，从而不可避免地导致大脑形状的变化。在成型过程中过度的压力可能会产生颅部出生损伤，并可能产生长期的后遗症，而错位和延长劳动力可能会导致骨盆底损伤，导致以后的生活中脱垂。在第二产程（通过阴道腔）期间，胎儿头骨和大脑所经历的应力（负荷）的大小尚不清楚。预测胎儿大脑和母体组织在第二产程期间所经历的压力，并了解成功分娩的参数，将有助于创造诊断工具，预测阴道分娩期间受伤的风险，从而进行预防。预测阴道分娩过程中受伤的风险也可以打开的可能性，区分在怀孕期间，劳动力和postpartum.Previous的尝试，估计产妇组织在劳动过程中所经历的应力和应变，主要是与刚性unmodeling胎头。“成功”分娩的一个关键机制是胎儿头骨的塑形能力，因此塑形头骨和母体组织之间的相互作用是预测母体和胎儿负荷的关键。有两项研究用可塑形的胎儿头骨模拟了分娩的第一阶段（子宫在下降到阴道腔之前的收缩），但这些研究没有调查分娩期间胎儿大脑的负荷经历。因此，成功地预测分娩期间胎儿脑负荷以及分娩第二阶段期间母体组织上的负荷将是该领域的重大进展。此外，参数化的模型将是开始建立一个病人的具体诊断工具，规划时，医疗干预是needed.This研究的目的是预测负荷的胎儿头部和母体组织与劳动力和了解的参数，最大的影响伤害的风险，通过计算机模拟。本研究建议通过与纽约哥伦比亚大学（Kristin Myers教授）合作，使用晚期妊娠的几何形状构建母体解剖结构的有限元（FE）模型。胎儿解剖结构将由卡迪夫大学提供的7天大婴儿的胎头FE模型表示（Mike D. Jones）。相关组织的现有材料响应数据将用于验证模型。通过在胎头上施加轨迹来模拟第二产程。该模型将被参数化，并将使用与阴道分娩相关的风险因素的现有知识来确定模型的哪些参数可以改变。该项目福尔斯属于EPSRC“医疗保健技术”研究领域，特别是“优化治疗”的重大挑战。

During vaginal labour the foetal head moulds to accommodate the geometric constraints of the birth canal and inevitably causes a change in the shape of the brain. Excessive stress during moulding can produce cranial birth injuries with possible long-term sequelae, while malpositioning and prolonged labour can cause pelvic floor damage leading to prolapse later in life. The magnitude of stress (loading) experienced by the foetal skull and brain during the second stage of labour (transit through the vaginal canal) is unknown. Predicting the stresses experienced by the foetal brain and maternal tissues during the second stage of labour and understanding the parameters for successful delivery would help create diagnostic tools for predicting the risk of injury during vaginal labour and therefore prevention. Predicting the risk of injury during vaginal labour could also open up the possibility of distinguishing between injuries sustained during pregnancy, labour, and post-partum.Previous attempts at estimating the stress and strain experienced by the maternal tissues during labour, have predominantly been with rigid unmoulding foetal heads. A key mechanism for a 'successful' labour is the ability of the foetal skull to mould and so the interaction between moulding skull and maternal tissues is key for predicting both the maternal and foetal loading. Two studies have simulated the first stage of labour (contractions of the uterus before descent into the vaginal canal) with a mouldable foetal skull but these studies have not investigated the loading experience by the foetal brain during labour. Therefore successfully predicting the foetal brain loading during labour alongside the loading on the maternal tissues during the second stage of labour would be significant progress in the field. Additionally, parameterising the model would be the beginning of building a patient specific diagnostic tool for planning when medical intervention is needed.This study aims to predict the loading of the foetal head and the maternal tissues associated with labour and understand the parameters that most greatly influence the risk of injury, through in silico simulation. This study proposes to build a finite element (FE) model of the maternal anatomy using the geometry of a late stage pregnancy through collaboration with Columbia University, NY (Professor Kristin Myers). The foetal anatomy will be represented by a foetal head FE model, of a 7-day-old infant, supplied by Cardiff university (Prof Mike D. Jones). Existing material response data of the associated tissues will be used to characterise the model. The second stage of labour will be simulated by imposing a trajectory on the foetal head. The model will then be parameterised and existing knowledge on the risk factors associated with vaginal labour will be used to determine which parameters of the model to vary.This project falls within the EPSRC 'Healthcare technologies' research area and specifically the grand challenge of 'Optimising Treatment'.