穿刺翻边的裂口缺陷

结合两个实例介绍了穿刺翻边裂口的形成过程,分析了产生裂口的原因,提出了解决裂口问题的措施。     

Healing DNA Self-Assemblies Using Punctures

In self-assembly, individual components (commonly referred to as tiles) have sufficient infor mation to build templates for structures such as lat tices for two-dimensional scaffolds. Tile sets that can heal (fully or partially) an erroneous DNA assembly have been proposed. Healing requires growth to be restarted such that erroneous tiles can be removed and the correct tiles can bind to the aggregate. Punctures have been proposed for this purpose; in this paper, a puncture is intentionally induced in the self-assembly to restart the growth process. The goal of this paper is to characterize an intentionally induced puncture (and its relevant properties) on an erroneous tile site in the grown crystal as part of a healing process. This allows to propagate any newly generated error away from the source of growth (i.e. the seed tile), such that self-assembly can continue along specific directions. Different types of puncture are considered with respect to healing and related features, such as growth direction, error and aggregate types. Punctures are analyzed using a new characterization and metric; different tile sets are investigated in detail for healing of a DNA self-assembly.

Measuring and Improving the Puncture Resistance of Self-Pressurized Containers

When self-pressurized containers, or aerosols, are accidentally dropped they are susceptible to puncture. The likelihood of puncture depends on the distance of the fall, the nature of the object that the aerosol might strike, the orientation of the impact, and the aerosol’s materials of construction, including microstructure. Due to the flammable nature of the propellants common to aerosols as well as other flammable contents, the accidental puncture of an aerosol has on occasion resulted in significant personal injury and property damage. While the Department of Transportation regulates several aspects of aerosol containers, there are no government regulations concerning puncture resistance. Likewise, there are no standard tests for the puncture resistance of aerosol containers. This article presents two different test methods that can be used to quantify the puncture resistance of aerosol containers. One mode of puncture is not a pure puncture, but rather an impact-induced circumferential puncture or crack. This is due to the anisotropic microstructure of the body material of most 3-piece steel aerosol containers. Experimental testing has shown that the most common type of aerosol container is highly vulnerable to impact-induced impact circumferential puncture. Free falls from a little as 20.32 cm (8 in.) onto wood pyramids are able to induce this type of puncture. This is a hidden and unexpected vulnerability inherent in most 3-piece steel aerosol containers. Experimental tests show that this susceptibility to impact-induced circumferential puncture as well as pure puncture can be greatly reduced, if not eliminated, by using container bodies with more isotropic microstructures.     

基于超声图像的PICC智能穿刺医疗机器人控制系统设计

为提高静脉穿刺置管手术的穿刺成功率,缓解病人所承担的生理性伤痛,设计基于超声图像的PICC（Peripheraly Inserted Central Cathcte,外周静脉置入的中心静脉导管）智能穿刺医疗机器人控制系统。以晶振复位电路作为穿刺置管的输出动力支持,通过驱动控制电机的传输调度作用,实现对智能传感器的精准化控制,降低置管过程中针头的平均进入深度,完成PICC智能穿刺医疗机器人及其控制应用结构搭建。在此基础上,按照静脉置管图像的实际特征分析结果,转换原有的超声图像格式,经过多次边缘性检测,实现对穿刺超声图像的初级预处理。获取静脉靶向血管的位置信息,在规划穿刺路径的同时,完成对机器人操作手的重定位控制,实现医疗机器人的运动控制模型分析。仿真对比实验结果显示,与常规静脉穿刺手段相比,穿刺控制系统可将进针角数值控制在10°-40°之间、进针深度保持在整个针头的2/3以内,可大幅提升穿刺置管的成功几率,实现减轻病人所承担生理性疼痛的目的。     

A Virtual Puncture Surgery System Based on Multi-Layer Soft Tissue and Force Mesh

Puncture is a common operation in surgery, which involves all kinds of tissue materials with different geometry and mechanical properties. As a new cross-disciplinary research area, Virtual Surgery (VS) makes simulation of soft tissue in puncture operation possible in virtual environment. In this paper, we introduce a VS-based puncture system composed by three-layer soft tissue, simulated with spherical harmonic function (SHF), which is covered with a force mesh, constructed by mass spring model (MSM). The two models are combined together with a parameter of SHF named surface radius, which provides MSM with real-time deformation data needed in force calculation. Meanwhile, force calculation, divided into the surface spring force and the puncture damping force, makes the force presentation better accord to the corresponding tissue characteristics. Moreover, a deformation resumption algorithm is leveraged to simulate the resumption phenomenon of the broken tissue surface. In evaluation experiment, several residents are invited to grades our model along with other four mainstream soft tissue models in terms of 7 different indicators. After the evaluation, the scores are analyzed by a comprehensive weighted grading method. Experiment results show that the proposed model has better performance during puncture operation than other models, and can well simulate surface resumption phenomenon when tissue surface is broken.     

颈内静脉穿刺置管术术前彩色多普勒超声定位和术后超声监测的研究

目的:评估彩色多普勒超声监测颈内静脉置管术的临床价值。方法:应用彩色多普勒超声实时监测120例患者的置管过程,对临床"盲穿"不成功的25例患者及"盲穿"后出现并发症的30例患者进行超声检查分析。结果:120例经实时超声监测的患者均取得成功,没有出现严重的并发症;临床盲穿不成功的原因有误穿颈总动脉、颈内静脉瓣膜过长、误穿颈外静脉、穿入颈内静脉或锁骨下静脉的对侧壁致使导丝不能下移;"盲穿"后出现的并发症主要为血肿、导管堵塞、胸锁乳突肌肿胀、静脉血栓形成、胸腔积血、误穿动脉、假性动脉瘤形成、导管周围纤维鞘膜形成等。结论:超声定位有助于顺利完成颈内静脉穿刺置管,并且对颈内静脉穿刺的各种并发症能够作出准确的诊断。     

爆胎车辆应急自动制动系统稳定控制的策略研究

在完成轨迹控制评价指标构建的基础上,对不同控制器控制爆胎车辆轨迹的效果进行了研究和分析,静态PID控制器通常基于某一车速建立导致对在其他行驶车速下的爆胎车辆行驶控制效果降低。为有效提升爆胎车辆的轨迹控制效果提出增益可变PID控制器。该控制器根据不同的爆胎车速标定事先获得相关参数,将该控制方案应用于轨迹控制仿真实验中,实现了对爆胎车辆行驶轨迹的有效控制过程,恢复到原路径时只出现了较小的偏移。     

HDPE/POE/CaCO3三元体系薄膜研究

采用聚烯烃弹性体（POE）和重质碳酸钙对HDPE薄膜进行改性,研究了POE和重质碳酸钙的用量对共混体系薄膜力学性能、流变性能的影响。结果表明,POE的加入,使HDPE／POE薄膜的单位落镖冲击破损质量增加,而拉伸强度则有所下降。当POE的质量分数为10％时,薄膜的单位落镖冲击破损质量提高了51．1％,但薄膜的拉伸强度下降了20．5％。在HDPE／POE／CaC03体系中,当POE、重质碳酸钙的质量分数分别为10％和5％时,薄膜的单位落镖冲击强度比纯HDPE提高95．6％,且拉伸强度不降低。     

BaTiO3陶瓷的击穿与电容器的耐压

本文介绍了ＢａＴｉＯ３陶瓷介质的极化机理,说明在居里温度以上和居里温度以下发生电击穿的部位是不同的,并用此理论解释了陶瓷材料的制造工艺特别是烧成条件对直流耐压胡较大影响的原因,此外还较全面地了添加剂,粘合剂及它们的用量以及资料中针孔的产生,加工缺陷等对耐压的影响。     

SystemView中time active用户自定义控件的实现

采用自定义控件是将SystemView仿真软件广泛应用于各种复杂或专用算法的有效手段。该文简单介绍了SystemView仿真软件用户自定义库的构成以及cdma2000 1x中符号删除模块的工作原理。较为详细地介绍了SystemView仿真软件的工作过程。重点介绍了用C 编程语言设计time active的general类用户自定义控件的方法。并以符合cdma2000 1x协议标准的符号删除模块为例,详细讲解了此模块的构建过程,给出了相应的源程序。为高级用户实现专用模块提供了一个方便的途径。