基于多级BP神经网络的EIT阻抗变化位置的确定

Electrical impedance tomography (EIT) is a new computer tomography technology, which reconstructs an impedance (resistivity, conductivity) distribution, or change of impedance, by making voltage and current measurements on the object's periphery. Image reconstruction in EIT is an ill-posed, non-linear inverse problem. A method for finding the place of impedance change in EIT is proposed in this paper, in which a multilevel BP neural network (MBPNN) is used to express the non-linear relation between the     

An integrated teaching method of gross anatomy and computed tomography radiology

It is essential for medical students to learn and comprehend human anatomy in three dimensions (3D). With this in mind, a new system was designed in order to integrate anatomical dissections with diagnostic computed tomography (CT) radiology. Cadavers were scanned by CT scanners, and students then consulted the postmortem CT images during cadaver dissection to gain a better understanding of 3D human anatomy and diagnostic radiology. Students used handheld digital imaging and communications in medicine viewers at the bench‐side (OsiriX on iPod touch or iPad), which enabled “pixel‐to‐tissue” direct comparisons of CT images and cadavers. Students had lectures and workshops on diagnostic radiology, and they completed study assignments where they discussed findings in the anatomy laboratory compared with CT radiology findings. This teaching method for gross and radiological anatomy was used beginning in 2009, and it yielded strongly positive student perspectives and significant improvements in radiology skills in later clinical courses. Anat Sci Educ 7: 438–449. © 2014 American Association of Anatomists.     

Development and implementation of a three-dimensional (3D) printing elective course for health science students

Three-dimensional (3D) printing technology has become more affordable, accessible, and relevant in healthcare, however, the knowledge of transforming medical images to physical prints still requires some level of training. Anatomy educators can play a pivotal role in introducing learners to 3D printing due to the spatial context inherent to learning anatomy. To bridge this knowledge gap and decrease the intimidation associated with learning 3D printing technology, an elective was developed through a collaboration between the Department of Anatomy and the Makers Lab at the University of California, San Francisco. A self-directed digital resource was created for the elective to guide learners through the 3D printing workflow, which begins with a patient's computed tomography digital imaging and communication in medicine (DICOM) file to a physical 3D printed model. In addition to practicing the 3D printing workflow during the elective, a series of guest speakers presented on 3D printing applications they utilize in their clinical practice and/or research laboratories. Student evaluations indicated that their intimidation associated with 3D printing decreased, the clinical and research topics were directly applicable to their intended careers, and they enjoyed the autonomy associated with the elective format. The elective and the associated digital resource provided students with the foundational knowledge of 3D printing, including the ability to extract, edit, manipulate, and 3D print from DICOM files, making 3D printing more accessible. The aim of disseminating this work is to help other anatomy educators adopt this curriculum at their institution.     

Digital body preservation: Technique and applications

High-fidelity anatomical models can be produced with three-dimensional (3D) scanning techniques and as such be digitally preserved, archived, and subsequently rendered through various media. Here, a novel methodology—digital body preservation—is presented for combining and matching scan geometry with radiographic imaging. The technique encompasses joining layers of 3D surface scans in an anatomical correct spatial relationship. To do so, a computed tomography (CT) volume is used as template to join and merge different surface scan geometries by means of nonrigid registration into a single environment. In addition, the use and applicability of the generated 3D models in digital learning modalities is presented. Finally, as computational expense is usually the main bottleneck in extended 3D applications, the influence of mesh simplification in combination with texture mapping on the quality of 3D models was investigated. The physical fidelity of the simplified meshes was evaluated in relation to their resolution and with respect to key anatomical features. Large- and medium-scale features were well preserved despite extensive 3D mesh simplification. Subtle fine-scale features, particular in curved areas demonstrated the major limitation to extensive mesh size reduction. Depending on the local topography, workable mesh sizes ranging from 10% to 3% of the original size could be obtained, making them usable in various learning applications and environments.     

Electrical process tomography: seeing "without eyes" inside stirred vessels

Body-scanning exploiting 3-D imaging has revolutionised diagnostics and treatment in medicine. Process engineers would like to be similarly able to image chemical process units in 3-D, but without the ￡multi-million price tag. UMIST and Leeds University have together, through the Virtual Centre for Industrial Process Tomography (http://www. vcipt.org), pioneered several electrical process tomography techniques and used them in a variety of applications. Illustrations are presented to show how electrical resistance tomography (ERT) has been developed for typical stirred vessels widely encountered in batch process manufacturing. The technique is potentially fast and inexpensive and capable of imaging both dynamic and pseudo-stationary processes. Examples from UMIST's two-tonne vessel will be presented for miscible tracer mixing, as well as gas-liquid and solid-liquid mixing.     

高压激励8极板电容层析成像系统研究

电容层析成像是检测封闭空间内部不同介电常数物质分布的有效技术手段。常见的电容层析成像系统被测对象直径一般为10 cm左右,电容检测电路的工作电压一般不超过20 Vpp。当ECT系统应用在粮仓等大尺寸的对象上时,需要提高激励电压以较高的灵敏度和分辨率,从而获得良好重建图像。文章介绍了高压激励电容层析成像系统的结构,给出了内置8极板电容传感器阵列的详细参数,并介绍了几种典型的分布模型的重建图像和误差数据。实验表明：本文所设计的高压电容层析成像系统具有良好的图像重建能力。     

Three-Dimensional Printing of Archived Human Fetal Material for Teaching Purposes

The practical aspect of human developmental biology education is often limited to the observation and use of animal models to illustrate developmental anatomy. This is due in part to the difficulty of accessing human embryonic and fetal specimens, and the sensitivity inherent to presenting these specimens as teaching materials. This report presents a new approach using three-dimensional (3D) printed replicas of actual human materials in practical classes, thus allowing for the inclusion of accurate examples of human developmental anatomy in the educational context. A series of 3D prints have been produced from digital data collected by computed tomography (CT) imaging of an archived series of preserved human embryonic and fetal specimens. The final versions of 3D prints have been generated in a range of single or multiple materials to illustrate the progression of human development, including the development of internal anatomy. Furthermore, multiple copies of each replica have been printed for large group teaching. In addition to the educational benefit of examining accurate 3D replicas, this approach lessens the potential for adverse student reaction (due to cultural background or personal experience) to observing actual human embryonic/fetal anatomical specimens, and reduces the potential of damage or loss of original specimens. This approach, in combination with ongoing improvements in the management and analysis of digital data and advances in scanning technology, has enormous potential to allow embryology students access to both local and international collections of human gestational material. Anat Sci Educ 00: 000–000. © 2018 American Association of Anatomists.     

Take away body parts! An investigation into the use of 3D‐printed anatomical models in undergraduate anatomy education

Understanding the three‐dimensional (3D) nature of the human form is imperative for effective medical practice and the emergence of 3D printing creates numerous opportunities to enhance aspects of medical and healthcare training. A recently deceased, un‐embalmed donor was scanned through high‐resolution computed tomography. The scan data underwent segmentation and post‐processing and a range of 3D‐printed anatomical models were produced. A four‐stage mixed‐methods study was conducted to evaluate the educational value of the models in a medical program. (1) A quantitative pre/post‐test to assess change in learner knowledge following 3D‐printed model usage in a small group tutorial; (2) student focus group (3) a qualitative student questionnaire regarding personal student model usage (4) teaching faculty evaluation. The use of 3D‐printed models in small‐group anatomy teaching session resulted in a significant increase in knowledge (P = 0.0001) when compared to didactic 2D‐image based teaching methods. Student focus groups yielded six key themes regarding the use of 3D‐printed anatomical models: model properties, teaching integration, resource integration, assessment, clinical imaging, and pathology and anatomical variation. Questionnaires detailed how students used the models in the home environment and integrated them with anatomical learning resources such as textbooks and anatomy lectures. In conclusion, 3D‐printed anatomical models can be successfully produced from the CT data set of a recently deceased donor. These models can be used in anatomy education as a teaching tool in their own right, as well as a method for augmenting the curriculum and complementing established learning modalities, such as dissection‐based teaching. Anat Sci Educ 11: 44–53. © 2017 American Association of Anatomists.     

装备电气三维虚拟教学系统设计与实现

针对装备电气传统教学方法不能适应现代装备发展需要的问题,设计了一套适用于＂武器装备电气系统＂系列课程的虚拟教学系统,采用3DSMax＋Cult3D＋Delphi方式来实现虚拟效果,并介绍了系统功能模块和详细的开发设计流程。该系统有利于学生自主学习,增强了教学互动性和沉浸感,提高了学习效果。     

Factors Contributing to Improved Teaching Performance

This article focuses upon the quality and scholarship of teaching as it pertains to educational and faculty development. We outline what more than 200 faculty members at one institution have done over a 3-year period to make significant and sustained improvements in their teaching, surprisingly with minimal effort. The top three factors leading to improvement were active/practical learning, teacher/student interactions, and clear expectations/learning outcomes. We provide practical applications for change and suggestions for future research. Whitney Ransom McGowan  is a Ph.D. candidate at Brigham Young University (BYU), and she received an M.S. degree in Instructional Psychology & Technology from BYU. She is currently a research assistant for the Assistant to the Academic Vice President at BYU and also performs research at the Center for Teaching & Learning. She can be contacted at whitney.ransom@gmail.com. Charles R. Graham  is an Associate Professor of Instructional Psychology and Technology at Brigham Young University with a focus on technology-mediated teaching and learning. Graham received his Ph.D. in Instructional Systems Technology from Indiana University. He received his M.S. degree in Electrical and Computer Engineering from the University of Illinois and his B.S. degree in Electrical and Computer Engineering, from BYU. He is particularly interested in studying the design and evaluation of blended learning environments. He can be contacted at charles_graham@byu.edu.     

高职院校《电机与电气控制技术》课程实训的改革探索

《电机与电气控制技术》课程实训,是指导学生所做的验证性实验,通过联接一些简单的控制电路或是到工厂参观一些电气设备,学生的实践及动手能力得不到培养、锻炼和提高。作者在近几年指导《电机与电气控制技术》课程的实训过程中做一些改革尝试,得到一些体验,供大家一起探索、思考。     

Use of 3-D magnetic resonance electrical impedance tomography in detecting human cerebral stroke： a simulation study

INTRODUCTION Magnetic Resonance Electrical Impedance To-mography (MREIT) is a new imaging techniquecombining traditional Electrical Impedance Tomo-graphy (EIT) and Current Density Imaging (CDI) fordetermining conductivity distribution inside a subject(Khang et al., 2002; Kwon et al., 2002). In MREIT, acurrent is injected into the subject through a pair ofsurface electrodes. The induced magnetic flux densityinside the subject can be measured through a Mag-netic Resonance …     

Towards precision medicine: from quantitative imaging to radiomics

Radiology (imaging) and imaging-guided interventions, which provide multi-parametric morphologic and functional information, are playing an increasingly significant role in precision medicine. Radiologists are trained to understand the imaging phenotypes, transcribe those observations (phenotypes) to correlate with underlying diseases and to characterize the images. However, in order to understand and characterize the molecular phenotype (to obtain genomic information) of solid heterogeneous tumours, the advanced sequencing of those tissues using biopsy is required. Thus, radiologists image the tissues from various views and angles in order to have the complete image phenotypes, thereby acquiring a huge amount of data. Deriving meaningful details from all these radiological data becomes challenging and raises the big data issues. Therefore, interest in the application of radiomics has been growing in recent years as it has the potential to provide significant interpretive and predictive information for decision support. Radiomics is a combination of conventional computer-aided diagnosis, deep learning methods, and human skills, and thus can be used for quantitative characterization of tumour phenotypes. This paper discusses the overview of radiomics workflow, the results of various radiomics-based studies conducted using various radiological images such as computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography (PET), the challenges we are facing, and the potential contribution of radiomics towards precision medicine.     

In-vivo retinal imaging by optical coherence tomography using an RSOD-based phase modulator

Fourier-domain rapid scanning optical delay line （RSOD） was introduced for phase modulation and depth scanning in a time-domain optical coherence tomography （TD-OCT） system. Investigation of parameter optimization of RSOD was conducted. Experiments for RSOD characterization at different parameters of the groove pitch, focal length, galvomirror size, etc. were performed. By implementing the optimized RSOD in our established TD-OCT system with a broadband light source centered at 840 nm with 50 nm bandwidth, in vivo retina imaging of a rabbit was presented, demonstrating the feasibility of high-quality TD-OCT imaging using an RSOD-based phase modulator.     

A novel technique of three-dimensional reconstruction segmentation and analysis for sliced images of biological tissues

INTRODUCTION The past decades witnessed unprecedented ad-vances in the imaging science fields(Yelbuz et al.,2002;Campagnola et al.,2002;Sharpe et al.,2002).The technique of3D image reconstruction andanalysis plays a significant role in the basic researchof life science,which developed from2D imageprocessing but provides more information than2Dimage,and has rapidly expanded to molecular andcellular field(Guo et al.,1995;Trehan et al.,2003).Despite the rapid development of the new field,…     

谈高职高专《电机与电气控制技术》课程的教学改革

高职高专教育是以就业为导向和培养高等技术应用型人才的教育。《电机与电气控制技术》是一门理论性、实践性、技术性和操作性都很强的专业课。《电机与电气控制技术》课程的教学改革应转变教育思想和观念;其二,加强实践性教学,培养学生的动手能力;其三,改进教学方法,提高学生的学习兴趣;最后是加强"双师素质"队伍的培养。     

体元模型法三维超声成像及其应用

三维超声成像是当前超声研究的一个热点。本文首先介绍了三维超声成像的发展现状。讨论了三维超声成像的研究内容与其中的关键技术,阐述了三维图像超声技术在临床医学的应用发展前景。     

贯彻电器制图新国标的情况调查和建议

电气制图及电气图形符号是电气技术领域中重要的基础标准之一.本文介绍了电气制图及电气图形符号国际及国内标准化概况,对新国标发布十多年来的贯彻情况作了深入调查,并提出建议.     

用超椭圆构造强正则图

在本中，我们证明了下面主要结果：如果U=（X，B）是一个t-(υ t,κ t,1）设计（t≥1),Y=(υ1，υ2，…，υt)∈X，用UY表示U在Y上的限制，如果D=UY是一个2-对称设计，并且D中的超椭圆的个数至多为tυ(υ-1)(υ-κ)/[κ(κ^2-1)]，则这些超椭圆可以分为t类，每一类构成一个2-设计，它们的块图都是强正则图，并且它们的并也是一个2-设计，作为一个推论，我们给出了一个2-设计可以扩张的判据，最后我们给出一个例子说明我们的方法有效。