重建耻骨联合三维结构用于活体年龄推断的技术方法

目的建立基于MRI成像的快速耻骨联合三维结构重建技术方法。方法利用3.0 T超导磁共振仪对成年男性志愿者骨盆进行T1小角度快速激发3D梯度回波序列扫描,进行二值化阈值分割、区域增长提取骨盆软组织图像;运算获得耻骨联合三维结构模型雏形,经逆向工程软件降噪处理建立耻骨联合三维结构模型,并与耻骨CT扫描三维结构重建模型进行比较。结果耻骨联合面沟嵴、下端、腹侧缘(斜面)、背侧缘(斜面)、耻骨结节等结构显示完整,无明显噪点,与CT扫描三维重建模型吻合较好。结论 MRI扫描成像可实现快速有效的耻骨联合三维结构重建,可为法医活体年龄推断提供安全无辐射作用的三维可视化影像学技术方法。     

高精度三维人脸图像数据库

3D人脸图像数据库广泛应用于计算机视觉、动画绘图设计、医学等很多领域。在法庭科学领域,采集三维人脸图像并建立数据库,可进行人像特征分类、统计人像特征的分布以及训练人像模型,这些分析是人像比对和识别的基础。与传统的二维数据库相比,三维(3D)人脸图像库能够提供更多信息,例如,三维人脸图像的空间结构和形状包含多视角轮廓。3D人脸图像采集方法包含多视角几何信息的方法、结构光的方法和3D扫描仪的方法,这些方法有不同的采集设备和环境。国内外已经建立了几个有代表性的3D人脸图像数据库,例如MPI实验室的MPI和BJUT的BJUT-3D,但这些库在分辨率和精度方面尚有不足。本文首先回顾了MPI、BJUT-3D数据库和它们的采集环境,然后对建立中国人的高精度3D人脸图像数据库进行探索研究。用彩色手持三维扫描仪(Artec Spider)采集了1100个3D人脸图像,这些图像包含彩色纹理和深度信息(几何形状和点云),每个人脸图像的几何形状的采样点数目超过2000万,三角面片数目超过4000万。与BJUT-3D人脸数据库在人脸形状、分辨率和纹理等方面的比较结果显示,本研究采集的人脸图像有更高的精度,在嘴巴、鼻子、眼睛等方面比其他数据库中的人脸图像显示了更多的细节。建立的数据库将会支持在3D人像识别和算法评估方面的进一步工作。     

从CT断层图像重建颅骨的三维表面

综述了从断层图像重建颅骨三维表面的几个步骤:断层图像预处理,三维表面的构造方法及显示方法。     

Matlab用于头颅CT数据重建和测量1例

计算机颅骨面貌复原是目前法医人类学研究的热点之一。而该研究中颅骨特征和五官特征之间的相关性研究不多,要研究颅骨和五官的相关性,首先要建立大样本的活体颅骨和面貌的三维测量数据库。利用活体薄层CT数据进行研究,既可以重建颅骨,也可以重建面貌,因而可以更好的研究其相关性。     

基于MSCT和Mimics软件构建人体颅骨三维有限元模型

目的 建立人体颅骨的有限元三维模型,探索人体颅骨有限元模型在生物力学分析中的价值.方法 用MSCT对尸体头部扫描后.使用Mimics建模软件对CT二维图像进行三维重建,并对原始三维颅骨模型优化,然后对模型进行面网格和体网格划分,利用ANSYS有限元分析软件验证颅骨被物体打击和颅骨撞击地面的不同应力变化.结果 原始三维颅...     

三维人脸图像的数据采集与预处理

在对人脸图像的研究中,三维图像可以弥补二维图像不能解决的多姿态多角度等问题,因此越来越受到重视。如何高效地大规模采集高清三维人脸图像仍是目前面临的一个值得深入研究的课题,包括设备选用、质量控制以及获取图像后的处理方法等。本文介绍了1100多份高清三维人像采集和处理过程中的方法、技巧以及需要注意的问题。一是设备的选择。在对扫描设备做了大量的资料查阅和性能比较后,选用了Artec Spider手持式3D扫描仪,它不仅使用方便且可以较好地获取被扫描物体的深度信息和彩色纹理,测量精度可达微米级别,适合用于获取高分辨的三维人脸图像。其次是在获取大量的三维脸像样本中如何做好图像质量的控制。由于手持式扫描仪在采集过程中易受到人为操作的不稳定因素影响,本研究摸索出适用的操作流程以提高采集质量和效率。三是采集后的数据处理。获取的原始数据是经过计算机实时配准的几百至上千个曲面的集合,采用了人工干预的方法来进一步提高曲面配准的精度。在大规模样本采集效率的分析方面,通过对预处理前后的图像质量、平均处理时间和单个样本的曲面采集数之间的关系进行分析,得出采集的曲面数在500~700帧之间的样本质量为最佳。     

基于特征轮廓线的三维颅骨配准方法

目的针对三维颅骨模型在初始姿态和分辨率上差异较大的情况,提出一种基于特征轮廓线的颅骨配准方法。方法首先,提取三维颅骨模型的眼眶、鼻框、颞骨、上颌骨以及下颌骨等轮廓线;然后,根据轮廓线的长度以及轮廓间的最短距离判断轮廓线的类型,并建立两个待配准颅骨在轮廓线上的对应关系,从而实现颅骨的粗配准;最后,通过添加权值的方式来改进迭代最近点(iterative closest point,ICP)算法,并采用该改进的ICP算法实现颅骨的细配准,从而达到两个颅骨精确配准的目的。结果通过将一个未知颅骨与颅骨数据库中的300个颅骨的配准实验表明,提出的基于特征轮廓线的配准算法可以实现三维颅骨模型的精确配准,并在细配准阶段取得了较高的配准精度和收敛速度。结论基于特征轮廓线的配准算法是一种快速、高精度的三维颅骨模型配准方法。     

中国汉族人颅骨数字模型的性别判别方法

目的利用步进Fisher法建立多元性别判别函数,对西安地区成年人颅骨进行性别判别。方法从颅面数据库中选择西安地区133个（73男,60女）三维颅骨模型,利用计算机软件测量并统计颅骨的12项几何测量指标和2项角度测量指标,利用步进Fisher方法建立多元性别判别函数,并对方程进行回代检验。结果男性的12项几何测量指标均值大于女性,女性的2项角度测量指标均值大于男性,除2项指标（X7和X14）外,其他指标均存在显著性差异（P〈0.01）。由4项指标建立的判别方程,判别率男性为87.5%,女性为86.67%。结论利用计算机软件可以实现完整颅骨和无下颌的颅骨的性别判别。     

基于CT三维重建技术推断西部地区汉族成人颅骨性别

目的 利用颅骨CT三维重组技术检验Walker模型推断我国西部地区汉族成人性别的可靠性和准确性,并研究适用于西部地区汉族人群的颅骨性别推断模型。方法 收集陕西省汉中医院2017—2021年的576例颅骨CT三维重组图像,分为实验组486例、验证组90例。观察者1采用Walker模型对实验组样本评分进行性别推断,并修正为适用于西部地区汉族样本的logistic函数,3名观察者对验证组90例样本评分,代入修正后的logistic函数完成回代检验。结果 应用Walker模型推断西部地区汉族成人性别准确率为63.2%～77.2%,修正的性别推断模型的准确率为82.9%。3名观察者回代检验性别推断准确率为75.6%～91.1%,观察者之间Kappa一致性检验结果为0.689(P<0.05),观察者内部Kappa一致性检验结果为0.874(P<0.05)。结论 不同地区人群骨骼特征存在差异,修正后的logistic函数在西部地区汉族成人获得了更高的准确率。     

基于深度学习实现成人坐骨耻骨支内侧缘的性别推断

目的 探究深度学习技术在中国汉族人群CT三维重建图像自动性别识别中的可靠性和准确率。方法 收集20～85岁汉族人群骨盆CT影像学数据700例（男性350例，女性350例），将其重建为三维虚拟骨骼模型，并截取坐骨耻骨支内侧缘（medial aspect of the ischiopubic ramus,MIPR）特征区域图像。采用Inception v4作为图像识别模型，以初始化学习和迁移学习两种方式进行训练。随机选取80%的图像作为训练验证集，20%的图像作为测试集。将左右两侧MIPR图像进行单独以及合并训练。之后使用总准确率、女性准确率、男性准确率等指标进行模型的性能评价。结果将左右两侧MIPR图像单独进行初始化学习训练，右侧MIPR模型的总准确率为95.7%，其中女性准确率为95.7%、男性准确率为95.7%；左侧MIPR模型的总准确率为92.1%，其中女性准确率为88.6%、男性准确率为95.7%。将左右两侧MIPR图像合并以初始化学习进行训练，模型的总准确率为94.6%，其中女性准确率为92.1%、男性准确率为97.1%。将左右两侧MIPR图像合并以迁移学习进行训练，模型的总准...     

现场分析处理技术的研究与思考

随着科技的发展，三维信息、三维虚拟现实动画已经越来越多的出现在人们的视野中。国内一些公安机关已经将三维虚拟技术应用到犯罪现场数据采集中，为了减少三维采集数据处理的时间，提高应用数据的效率。本文将研究方向定位在研发一个集一维信息、二维信息、三维信息、漫游系统、三维仿真动画等功能于一身的三维制作平台，并探讨其在案件侦查中的运用。     

Accuracy of 3D Scanners in Tooth Mark Analysis

The objective of this study was to compare the accuracy of contact and laser 3D scanners in tooth mark analysis. Ten dental casts were scanned with both 3D scanners. Seven linear measurements were made from the 3D images of dental casts and biting edges generated with DentalPrint© software (University of Granada, Granada, Spain). The uncertainty value for contact 3D scanning was 0.833 for the upper dental cast and 0.660 mm for the lower cast; similar uncertainty values were found for 3D-laser scanning. Slightly higher uncertainty values were obtained for the 3D biting edges generated. The uncertainty values for single measurements ranged from 0.1 to 0.3 mm with the exception of the intercanine distance, in which higher values were obtained. Knowledge of the error rate in the 3D scanning of dental casts and biting edges is especially relevant to be applied in practical forensic cases.     

Portable high‐resolution automated 3D imaging for footwear and tire impression capture

The forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation for field and laboratory use. While the 3D optical techniques for imaging static objects have been extensively studied, there is still a major gap between current knowledge and collecting high‐quality footwear and tire impression evidence. Among optical means for 3D imaging, digital fringe projection (DFP) techniques reconstruct 3D shape from phase information, achieving camera‐pixel spatial resolution. This paper presents a high‐resolution 3D imaging technology using DFP techniques dedicated to footwear and tire impression capture. We developed fully automated software algorithms and a graphical user interface (GUI) that allow anyone without training to operate for high‐quality 3D data capture. We performed accuracy evaluations and comparisons comparing with the commercial high‐end 3D scanner and carried out qualitative tests for various impressions comparing with the current practices. Overall, our technology achieves similar levels of accuracy and resolution with a high‐end commercially available 3D scanner, while having the merits of being (1) more affordable; (2) much easier to operate; and (3) more robust. Compared with the current practice of casting, our technology demonstrates its superiority because it (1) is non‐destructive; (2) collects more evidence detail than casts, especially when an impression is fragile; (3) requires less time and money to collect each piece of evidence; and (4) results in a digital file that can easily be shared with other examiners.     

Accuracy and Reproducibility of Bullet Trajectories in FARO Zone 3D

With three-dimensional (3D) laser scanning technology and software packages, the practice of documenting and measuring bullet trajectories has benefited from greater accuracy and reproducibility. This study investigated the accuracy and reproducibility of the bullet trajectory tools in the software package, FARO Zone 3D (FZ3D). Twelve participants were provided laser scanner data for 21 bullet trajectories on drywall panels with impact angles between 25° and 90°. When the impact plane was manually aligned by the operator, 75% of the absolute errors were within 0.91° and 0.98° for the azimuth and vertical angles, respectively. The vertical angle improved to 0.47° when impact plane alignment was taken with respect to gravity (no operator influence). Thus, manual alignment is shown to be subject to greater error than alignment with gravity. However, this study shows that the accuracy and reproducibility of the FZ3D bullet trajectory tools to be comparable with previous research studies.     

Haptics in forensics: The possibilities and advantages in using the haptic device for reconstruction approaches in forensic science

Non-invasive documentation methods such as surface scanning and radiological imaging are gaining in importance in the forensic field. These three-dimensional technologies provide digital 3D data, which are processed and handled in the computer. However, the sense of touch gets lost using the virtual approach. The haptic device enables the use of the sense of touch to handle and feel digital 3D data. The multifunctional application of a haptic device for forensic approaches is evaluated and illustrated in three different cases: the representation of bone fractures of the lower extremities, by traffic accidents, in a non-invasive manner; the comparison of bone injuries with the presumed injury-inflicting instrument; and in a gunshot case, the identification of the gun by the muzzle imprint, and the reconstruction of the holding position of the gun.The 3D models of the bones are generated from the Computed Tomography (CT) images. The 3D models of the exterior injuries, the injury-inflicting tools and the bone injuries, where a higher resolution is necessary, are created by the optical surface scan.The haptic device is used in combination with the software FreeForm Modelling Plus™ for touching the surface of the 3D models to feel the minute injuries and the surface of tools, to reposition displaced bone parts and to compare an injury-causing instrument with an injury.The repositioning of 3D models in a reconstruction is easier, faster and more precisely executed by means of using the sense of touch and with the user-friendly movement in the 3D space. For representation purposes, the fracture lines of bones are coloured. This work demonstrates that the haptic device is a suitable and efficient application in forensic science. The haptic device offers a new way in the handling of digital data in the virtual 3D space.     

An Overview of 3D Printing in Forensic Science: The Tangible Third-Dimension

There has been a rapid development and utilization of three-dimensional (3D) printing technologies in engineering, health care, and dentistry. Like many technologies in overlapping disciplines, these techniques have proved to be useful and hence incorporated into the forensic sciences. Therefore, this paper describes how the potential of using 3D printing is being recognized within the various sub-disciplines of forensic science and suggests areas for future applications. For instance, the application can create a permanent record of an object or scene that can be used as demonstrative evidence, preserving the integrity of the actual object or scene. Likewise, 3D printing can help with the visualization of evidential spatial relationships within a scene and increase the understanding of complex terminology within a courtroom. However, while the application of 3D printing to forensic science is beneficial, currently there is limited research demonstrated in the literature and a lack of reporting skewing the visibility of the applications. Therefore, this article highlights the need to create good practice for 3D printing across the forensic science process, the need to develop accurate and admissible 3D printed models while exploring the techniques, accuracy and bias within the courtroom, and calls for the alignment of future research and agendas perhaps in the form of a specialist working group.     

Determining the Effectiveness of Noncontact Three-Dimensional Surface Scanning for the Assessment of Open Injuries

Noncontact three-dimensional (3D) surface scanning methods are used within forensic medicine to record traumas and other related findings. A structured light scanning technique is one of these methods and the most suitable for the forensic field. An assessment of the efficiency of different structured light scanners with forensic injuries is essential to validate this technique for wound documentation. The purpose of this study was to evaluate the capability of the HP structured light scanner Pro S3 for digitizing open injuries having complicated areas and depths. Fifteen simulated injuries on mannequins were scanned and assessed. Comparisons between 3D and direct wound measurements were made. The results showed that the technique was able to create detailed 3D results of the extensive injuries. Statistical significance tests revealed no difference between the two measurement methods. Because the scanner is applicable for routine work, it should be considered to confirm the same results on real cadavers and actual wounds.     

3D打印治安管理对策研究

3D打印技术如今已受到了社会各界广泛的关注,有着良好的发展前景。然而其本身也具有着一定的治安隐患,如危险物品泛滥、特殊物品复制等。对于3D打印技术,需要进行系统的风险评估,并通过完善机制的构建进行人为控制,以保证其健康发展。这一机制的构建,除了应运用较多的高科技手段外,也应当在管理规范层面做到有序、协调。     

Hierarchical,Three‐Dimensional Measurement System for Crime Scene Scanning

We present a new generation of three‐dimensional (3D) measuring systems, developed for the process of crime scene documentation. This measuring system facilitates the preparation of more insightful, complete, and objective documentation for crime scenes. Our system reflects the actual requirements for hierarchical documentation, and it consists of three independent 3D scanners: a laser scanner for overall measurements, a situational structured light scanner for more minute measurements, and a detailed structured light scanner for the most detailed parts of tscene. Each scanner has its own spatial resolution, of 2.0, 0.3, and 0.05 mm, respectively. The results of interviews we have conducted with technicians indicate that our developed 3D measuring system has significant potential to become a useful tool for forensic technicians. To ensure the maximum compatibility of our measuring system with the standards that regulate the documentation process, we have also performed a metrological validation and designated the maximum permissible length measurement error E_MPE for each structured light scanner. In this study, we present additional results regarding documentation processes conducted during crime scene inspections and a training session.     

DRD3基因对精神分裂症研究的法医学意义

阐明精神分裂症的病因和发病机制是医学面临的重要挑战之一,同时也是法医司法鉴定的重要内容之一。精神分裂症的多巴胺假说认为多巴胺能系统的失调是精神分裂症的病因,DRD3基因在脑中的区域性高表达以及其与众多精神疾病的阳性关联提示其在精神分裂症中的潜在重要性。本文综述了DRD3基因在精神分裂症的群体遗传学、动物模型和在人源细胞表达情况的研究现状,认为DRD3基因参与精神分裂症的发病机制并且在未来可能作为一个重要的遗传学指标而应用到法医精神病学的鉴定当中。