We consider the problem of assessing bone fracture risk for a subject hit by a blunt impact projectile. We aim at constructing a framework for integrating test data and Advanced Total Body Model (ATBM) simulations int...We consider the problem of assessing bone fracture risk for a subject hit by a blunt impact projectile. We aim at constructing a framework for integrating test data and Advanced Total Body Model (ATBM) simulations into the risk assessment. The ATBM is a finite element model managed by the Joint Non-Lethal Weapons Directorate for the purpose of assessing the risk of injury caused by blunt impacts from non-lethal weapons. In ATBM simulations, the quantity that determines arm bone fracture is the calculated maximum strain in the bone. The main obstacle to accurate prediction is that the calculated strain is incompatible with the measured strain. The fracture strain measured in bending tests of real bones is affected by random inhomogeneity in bones and uncertainty in measurement gauge attachment location/orientation. In contrast, the strain calculated in ATBM simulations is based on the assumption that all bones are perfectly elastic with homogeneous material properties and no measurement uncertainty. To connect test data and ATBM simulations in a proper and meaningful setting, we introduce the concept of elasticity-homogenized strain. We interpret test data in terms of the homogenized strain, and build an empirical dose-injury model with the homogenized strain as the input dose for predicting injury. The maximum strain calculated by ATBM has randomness due to uncertainty in specifications of ATBM setup parameters. The dose propagation uncertainty formulation accommodates this uncertainty efficiently by simply updating the shape parameters in the dose-injury model, avoiding the high computational cost of sampling this uncertainty via multiple ATBM runs.展开更多
文摘目的探讨短暂性脑缺血发作(transient ischemic attacks,TIA)患者采用负荷剂量氯吡格雷治疗的临床效果。方法选取2020年6月—2022年6月厦门市第五医院收治的88例TIA患者。以随机数字表法分为研究组(n=44)和对照组(n=44)。2组均接受了血管扩张剂和神经保护药物等治疗,对照组给予常规剂量氯吡格雷治疗,研究组给予负荷剂量氯吡格雷治疗。比较2组临床疗效、神经功能、预后及不良反应。结果研究组的治疗总有效率(95.45%)高于对照组(79.55%)(P<0.05)。2组在治疗1、2周后,美国国立卫生研究院卒中量表(National Institutes of Health stroke scale,NIHSS)评分都有所降低(P<0.05),研究组治疗1、2周后NIHSS评分低于对照组(P<0.05)。2组治疗后改良Rankin量表(modified Rankin scale,mRS)评分降低(P<0.05),研究组评分低于对照组(P<0.05)。研究组不良反应总发生率(6.82%)与对照组(11.36%)比较,差异无统计学意义(P>0.05)。结论TIA患者采用负荷剂量氯吡格雷治疗具有确切的临床疗效,可有效改善神经功能及预后,且不会增加药物不良反应,体现了《短暂性脑缺血发作与轻型卒中抗血小板治疗中国专家共识》的执行标准。
文摘We consider the problem of assessing bone fracture risk for a subject hit by a blunt impact projectile. We aim at constructing a framework for integrating test data and Advanced Total Body Model (ATBM) simulations into the risk assessment. The ATBM is a finite element model managed by the Joint Non-Lethal Weapons Directorate for the purpose of assessing the risk of injury caused by blunt impacts from non-lethal weapons. In ATBM simulations, the quantity that determines arm bone fracture is the calculated maximum strain in the bone. The main obstacle to accurate prediction is that the calculated strain is incompatible with the measured strain. The fracture strain measured in bending tests of real bones is affected by random inhomogeneity in bones and uncertainty in measurement gauge attachment location/orientation. In contrast, the strain calculated in ATBM simulations is based on the assumption that all bones are perfectly elastic with homogeneous material properties and no measurement uncertainty. To connect test data and ATBM simulations in a proper and meaningful setting, we introduce the concept of elasticity-homogenized strain. We interpret test data in terms of the homogenized strain, and build an empirical dose-injury model with the homogenized strain as the input dose for predicting injury. The maximum strain calculated by ATBM has randomness due to uncertainty in specifications of ATBM setup parameters. The dose propagation uncertainty formulation accommodates this uncertainty efficiently by simply updating the shape parameters in the dose-injury model, avoiding the high computational cost of sampling this uncertainty via multiple ATBM runs.
