基于小波和卡尔曼平滑的事件相关电位单次提取

本研究提出一种事件相关电位单次提取方法,可有效减少实验次数,并可探索实验之间ERP的变异性。此方法基于小波和卡尔曼平滑,首先利用小波变换考察ERP平均信号的时频特性,根据ERP不同分量出现的时间位置,在不同尺度上选取特定的单次实验ERP小波系数构成观测向量,其为真实ERP小波系数状态向量与噪声之和,然后对观测向量进行卡尔曼平滑,最后对卡尔曼平滑后的小波系数进行小波重构,得到单次提取的ERP信号。仿真实验表明,基于小波和卡尔曼平滑的方法不仅信噪比提高约16~18 dB,优于30次叠加平均、简单小波方法和基于高斯基函数的卡尔曼滤波方法,还可以跟踪ERP的幅度趋势变异性。与基于高斯基函数的卡尔曼滤波方法相比,所提方法降低了计算量。真实脑电ERP提取实验表明本方法较好地从单次记录中提取出了事件相关电位,并可解释ERP因适应和应激引起的趋势变异性。     

基于参数模型和独立分量分析的事件相关诱发电位单次提取

我们针对脑电事件相关电位（ERP）这种信噪比极低的信号检测问题，提出了两种ERP信号单次提取方法，能非常有效地同时去除自发脑电、眼动伪迹和工频噪声三种常见噪声。（1）首次对自发脑电、眼动伪迹和工频噪声这三种常见成分连同事件相关电位同时进行ARX建模，利用基于最小二乘（Ls）的ARX算法进行参数辨识获得提取结果；（2）利用独立分量分析，采用FastICA算法进行事件相关电位的提取。明确指出ICA分解的一些重要分解特性及其内在机理，针对实际情况对FastICA算法进行了改进，实现了分解结果对ERP成分的自适应映射。数值仿真实验结果表明两种方法均有较高的信号分解提取能力。     

事件相关电位频谱分析研究

本文报告31名正常事件相关电位(ERP)的频谱分析结果.进行数字滤波后,将ERP_3的功率分三个频带H_z;7—13Hz,1—7Hz,1—13Hz进行取样分析,绘图。并就快速付力叶变换的方法及其实际意义作了讨论。     

结合子空间方法和提升小波变换提取事件相关脑电位

我们提出了一种提取事件相关脑电位的复合方法。它用奇异值分解方法将含噪信号分解为噪声子空间和信号子空间,将含噪信号正交投影到信号子空间进行初步除噪,随后将得到的信号进行提升小波变换,对变换结果进行一维小波重构进一步去除噪声,最后提取出ERP成分。介绍了基于奇异值分解的子空间方法和对信号进行提升小波去噪的实现方法。仿真结果表明,结合两种方法提取事件相关脑电信号时,比单独采用其中一种方法的效果要好,并可减少提取事件相关电位所需的实验次数。对实验数据的处理结果表明,该方法的实际处理效果良好。     

基于小波变换和盲源分离算法提取事件相关电位

阐述了用小波分解和盲源分离(blind source separation,BSS)算法结合来去除噪声和干扰提取事件相关电位(event-related potential,ERP).采用小波变换分解ERP,抽取出不同频带的细节信息;由小波系数判断选择多个尺度的子带信号,将它们分别与原始ERP组合进行盲分离,方法是极大化信号时间上的可预测性;将分离的结果进一步叠加平均.两类ERP仿真实验结果表明,本文算法提取出的ERP主要成分波明显,易于辨识,信噪比比较单独运用盲分离算法提取出的结果要好.在应用实例中,有效地增强了ERP的μ波.该算法优点在于减少了刺激次数和波形失真,参数变化范围小,在临床上有很好的应用前景.     

听觉新奇事件相关电位的研究进展

就人脑对听觉新奇事件的事件相关电位(Event-related potentials,ERP)响应的研究进展进行了综述。介绍了新奇性响应的实验方案设计和新奇性响应ERP在认知方面的一系列问题。对反映偏离检测的非匹配负波电位(MMN)以及与新奇性响应的关系也进行了讨论。熟悉度和注意力两个因素影响着大脑的新奇性ERP响应。研究表明,随熟悉程度的加强,在脑前区体现出信号明显的减小,而脑后区无明显变化。注意的作用有助于信号的加强,使大脑相应的部位产生激活。本文进一步讨论了ERP响应的功能意义,包括大脑对新奇事件的估价等内容。     

事件相关电位

事件相关电位(event-related potential,简称ERP)最早由Sutton在1965年开始研究。在以后的四十多年中,ERP的实验研究和临床上的应用得到了很大的发展。我院自1994年就开展了ERP的临床应用研究,我们除了对正常儿童、青年人进行了不同刺激诱发ERP的测定外,至今已检测了临床各种疾病患者近万例。本文笔者想就ERP的概念、原理、方法、内容、影响因素以及临床上一些疾病的ERP的改变和临床意义作一简要介绍。概念和原理众所周知,ERP属于诱发电位,但它不同于一般的诱发电位,而是一种特殊的诱发电位,属于近场电位之一。它反映人对一个事件…     

基于小波变换的事件相关电位少次提取方法

本文以反映大脑稀少认知事件的相关电位P300为例,介绍了基于小波变换(wavelet transform,WT)进行事件相关电位(event related potential,ERP)少次提取的原理、仿真和实验结果.通过小波变换先去除与ERP混杂的EEG背景干扰,然后对消除干扰后的脑电数据进行重构和ERP波峰检测,在此基础上尝试修正ERP波峰的潜伏期时移,再通过小波重构获得通常需多次相干平均才能得到的ERP波形.仿真计算和实验数据分析结果说明小波分析具有较强的ERP峰值检测和潜伏期模式识别能力,值得进一步在临床工程中深入研究和应用推广.     

脑电信号与经穴输入信号相关分析的实验研究

利用不同频率电脉冲信号作用于人体不同经穴上，通过对经穴输入信号与脑电波输出信号之间的相关性研究，探索一种经穴优化输入的新方法，确立经络与大脑之间的动态关联性。实验研究表明30Hz的断续波电脉冲刺激信号与其诱发的脑电α2波相关性最强，使用30Hz的断续波电脉冲刺激天枢、大肠俞这组穴位有利于诱发大脑的有益波态α波。     

癫癎患者听觉事件相关电位的检测报告

目的:探讨听觉事件相关电位(ERP)在癫癎患者中的应用价值。方法:对40例癫癎患者和30名正常人进行ERP检测比较,并将癫癎患者ERP的结果与其发作类型、用药情况等进行比较分析。结果:40例癫癎患者的ERP P300潜伏期较对照组延长(P<0．05),但其P300波幅差异无统计学意义(P>0．05)。全身强直阵挛性发作的28例癫癎患者,P300潜伏期延长尤著。多药治疗组较单药治疗组P300潜伏期延长。结论:癫癎患者存在认识功能障碍,ERP可作为癫癎患者认知功能障碍诊断的参考指标,对指导临床,及早给予干预和治疗有一定意义。     

Progress of the laboratory supporting system of the ordering system]

University hospitals and large public hospitals introduced a first-generation ordering system, which mainly involved an integrated system developed by each institution. This type of system considerably improved the efficiency of hospital jobs, but clinically increased the burden of data-input handling of hospital staffs because the software used was unique to the respective unit. Later, the development of both network technology and package software for the ordering system allowed construction of an easy, low-cost and high-performance ordering system. Most of the recent ordering systems are a type of distributed system which is referred to as a client-server system. In this system the terminal was replaced by personal computer loaded with widely distributed Windows OS, resulting in better performance of multi-tasks. In February 1998, our hospital information system was changed from an intensive host-type to a client-server system, in which the laboratory ordering system was also reconstructed. The laboratory ordering system mainly utilizes EG Main for Windows, package software by Fujitsu Co. Ltd., and has reduced the handling of laboratory ordering jobs with Graphical User Interface and better construction of screen images. In addition to extra-laboratory tests, ordering into this system allowed the database of all the laboratory tests ordered in our hospital to be unified. The previous laboratory ordering system supported laboratory data, especially those of laboratory tests and samples conducted within the last 10 years, and the new system will also provide this function. The new laboratory ordering system is further expected to support reference image-data from physiological tests as well as to allow consultation concerning laboratory test data. These clinical job-supporting systems will likely lead to further progress of the total laboratory system.     

Performance evaluation of a "dual-side read" dedicated mammography computed radiography system

The image quality of a dedicated mammography computed radiography (CR) system was characterized. A unique feature of this system is that it collects image signals from both sides of the storage phosphor. Measurements of the modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were made. This work included improvements in our measurement methods to specifically account for the detrimental effects of system glare on the MTF and to accurately characterize the low-frequency NPS components. Image quality measurements were performed using a 25 kVp beam filtered with 2 mm Al and an exposure range of 1 to 100 mR (87 to 870 microGy). The DQE was found to decrease with increasing exposure due to an increased contribution of storage phosphor structure noise. The DQE of this system was compared to similar measurements made using a standard CR system. The dual-side read system demonstrated superior DQE compared to the standard system. The decrease in DQE with increasing exposure was more severe for the standard system than the dual-side read system. This finding suggests that the CR system noise was reduced for the dual-side read system compared to the standard system.     

A Robotic Flexible Drill and Its Navigation System for Total Hip Arthroplasty

This paper presents a robotic flexible drill and its navigation system for total hip arthroplasty (THA). The new robotic system provides an unprecedented and unique capability to perform curved femoral milling under the guidance of a multimodality navigation system. The robotic system consists of three components. Firstly, a flexible drill manipulator comprises multiple rigid segments that act as a sheath to a flexible shaft with a drill/burr attached to the end. The second part of the robotic system is a hybrid tracking system that consists of an optical tracking system and a position tracking system. Optical tracking units are used to track the surgical objects and tools outside the drilling area, while a rotary encoder placed at each joint of the sheath is synchronized to provide the position information for the flexible manipulator with its virtual object. Finally, the flexible drill is integrated into a computer-aided navigation system. The navigation system provides real time guidance to a surgeon during the procedure. The flexible drill system is then able to implement THA by bone milling. The final section of this paper is an evaluation of the flexible and steerable drill and its navigation system for femoral bone milling in sawbones.     

磁导航外科手术模型系统设计和建造

磁导航外科手术系统是一种利用外界磁场引导药物或其它治疗手段在患者体内完成复杂外科手术的一种全新的治疗设备.它主要由超导磁体系统、立体定向成像系统、监视、控制系统、人机交互界面、电源系统、介入式手术器械等部分组成.根据该系统对磁体的特殊要求,首先设计并建造了新的磁体结构,并最终设计、建造了国内首台磁导航外科手术模型系统,试验结果显示该系统工作正常,较好的模拟了磁导航外科手术系统的基本功能,取得了令人满意的试验结果.     

Systemic mechanisms of nervous disorders]

Apart from the lesion and destruction of nervous structures and nervous links there is a different, so far little known, aspect of pathogenesis of nervous disorders, i.e. appearance of new pathological integrations in the nervous system. Formation and activity of these integrations is realized by endogenous, intrinsic to the damaged nervous system itself mechanisms. Pathologic integration occurring at the level of systemic relations is a pathologic system. The main biological sign of a pathologic system, due to which it differs from a physiologic system, is a dysadaptive or directly pathogenic significance of its activity for the organism. The pathologic system may be originate as a result of hyperactivation and loss of control over the physiologic system or due to the formation of a new, pathodynamic organization in the central nervous system. The neuropathological syndrome is clinical expression of the corresponding pathologic system activity. Every syndrome has its pathologic system and the specificity of the syndrome depends on what structures of the central nervous system are part of the pathologic system. Simple, linear pathologic systems underlie the monomorphic syndromes and symptoms, and complex ones underlie the polymorphic syndromes. Due to plasticity the positive connections between the parts of the pathologic system are consolidated therefore with course of time the resistance of the pathologic system to the endogenous sanogenetic mechanisms and to therapy increases. Stabilization of pathologic system underlies the chronization of nervous disorders. The concept of the pathologic system as a basic pathophysiological mechanism of nervous disorders is a new approach to understanding pathogenesis, elaboration of models and development of new principles and method of treatment of nervous disorders.     

Rapid antimicrobial susceptibility testing of Gram-negative clinical isolates with the AutoMicrobic system

Comparisons of the antimicrobial susceptibility patterns of clinical isolates of the family Enterobacteriaceae and Pseudomonas aeruginosa were made by using Kirby-Bauer disk diffusion, the MicroMedia system broth microdilution, and the AutoMicrobic system. The Kirby-Bauer system compared favorably with the MicroMedia system (95% essential correlation with 90% complete agreement). The AutoMicrobic system also compared favorably with both the Kirby-Bauer system (93% essential correlation with 87% complete agreement) and the MicroMedia system (97% essential correlation with 85% complete agreement). These data indicate that the AutoMicrobic system results are comparable to those of the MicroMedia and the Kirby-Bauer systems. Furthermore, the AutoMicrobic system offers a more rapid system (6 to 10 h), than the traditional systems, without sacrificing accuracy (16 to 24 h).     

新型立体定向放射外科治疗设备—Zap-X

精确的剂量照射是立体定向放射外科治疗成功的关键。Zap-X系统是一款具有自屏蔽功能的辐射治疗设备,用于脑部及头颈部肿瘤的立体定向放射外科治疗。本研究针对Zap-X系统的相关技术特点进行简述,分别从机械结构、自屏蔽系统、机械运动系统、辐射准直器系统、治疗计划系统、kV图像引导系统、MV影像验证系统等方面着重介绍了Zap-X系统的组成,阐述该系统的治疗过程,并总结对比其临床应用,最后对该系统的未来发展方向提出展望。其旋转式准直器的设计加上自身屏蔽防护的设计极大地降低了设备安装成本,可移动式MV探测器能实时监测治疗过程中的剂量准确性,采用直线加速器代替放射源,安全性、稳定性得到一定程度的提高。作为系统的初代产品,该设备还有诸多技术环节有待进一步改善。     

基于生物电阻抗法的人体成分测量系统的研究与评价

目的：本文探讨了生物电阻抗测量系统对人体成分的测量效果与适用性。从而为测量人体成分时选择合适的测量系统提供了技术支持与理论依据。方法：对生物电阻抗测量系统进行了深人的研究与评价,剖析总结了生物电阻抗法测量系统存在的问题,并对生物电阻抗法测量人体成分的影响因素进行了归纳与总结,最后对生物电阻抗法测量人体成分的未来发展进行了展望。结果：生物电阻抗法测量系统经历了从单频率全身测量系统到多频率人体分段电阻抗测量系统的发展过程,测量系统本身所具有的特性及外界因素都会对整个测量系统有一定干扰,所以针对不同的测量需要选择合适的测量系统与测量方案可以最大限度的减少干扰。结论：生物电阻抗法是测量人体成分的理想方法,生物电阻抗法测量系统的选择是人体成分测量的关键。随着研究推进,将会出现适用于人体局部的电阻抗测量系统。     

Design of a continuous-wave Doppler ultrasonic flowmeter for perivascular application

The paper details the design of the signal processing system of an ultrasonic Doppler flowmeter intended for perivascular application. The system is designed to work in conjunction with a transducer system described in an earlier paper, in a range of vessels varying from 5 mm to 12 mm. The system incorporates conventional quadrature processing for directional discrimination and uses phaselocked loop technology to extract signals corresponding to the instantaneous mean frequency (velocity equivalent). The use of a PLL also permits the extraction of a quasi-spectral analysis signal. The baseline stability of the Doppler system is enhanced by the use of an auto-zeroing system which enables the system to resolve Doppler shifts down to 20Hz. Testing of the complete transducer/signal processor system in a hydraulic rig demonstrates the ability of the flowmeter to accurately measure both steady and pulsatile flow.     

Development of the reimbursement system based on DPC

In the health insurance system of Japan, a fee-for-service system has been applied to individual treatment services, but this fee system involves a structural problem of causing increases in examinations and drug administration. Various attempts have been made to solve this structural problem in several treatment fields, in which a flat payment system can be introduced with the fee for-service system as the basis. The diagnosis procedure combination (DPC) system introduced in April 2003, which is a flat payment system using a diagnosis classification, is the first large scale revision of the medical fee system of Japan. This diagnosis classification is considered to be effective for simplifying the medical fee system, within the framework of EBM, and for providing patients with information. However, since there are also structural problems in the flat payment system, such as examination and treatment of low quality, selection of patients, and upcoding, its introduction should be performed with sufficient caution. We will make more efforts to establish a better medical fee system by evaluating these problems.