程控X线机故障采集卡的研制

目的:为了解决故障设置法教学中因FSK302-1A型程控X线机不具备语音报警而引起的种种不便,特提出一种程控X线机语音故障采集卡的设计方案.方法:在分析程控X线机旋转阳极、灯丝预热、主可控硅损坏、手闸信号、电源波动、透视限时等检测原理的基础上,找出其在CPU板上的对应信号,通过采集卡的接口电路完成故障信号的采集.采集卡硬件系统主要包括单片机ATA89C52、语音芯片ISD4004、接口电路等部分,软件系统包括录音编址、语音故障报警等模块.结果:本采集卡简单实用,大大提高了教学质量.结论:对于其他种类的程控X线机和高频X线机,该方案具有重要的参考价值.     

基于通信模式的虚拟程控X线机的设计与实现

目的:为了解决程控X线机在教学和实验中存在的设备费用高、体积大等缺点,提出开发虚拟程控X线机的方案.方法:以VB和SQL数据库为平台,利用上位机ActiveX控件开发虚拟X线机操作台,完成曝光参数的设定与显示、曝光过程、器官程序摄影等功能,同时设计下位机系统完成旋转阳极启动及延时、灯丝预热和曝光过程.上位机与下位机以通讯方式完成数据和命令的传送.结果:该虚拟X线机不但功能齐全而且费用低、使用方便.结论:对于其它医学仪器的虚拟设计,该方案具有重要的参考价值.     

虚拟仿真教学在《医学影像设备学》教学中的研究与应用

目的：为了克服医学影像设备在教学中存在的原理抽象、教学成本高等种种限制,提出开发医学影像设备虚拟仿真教学系统的方案。方法：以万东程控X线机为例,以VisualBasic6．0和Keil C51为开发平台,在PC机上模拟操作台的功能．利用下位机系统完成旋转阳极启动、灯丝预热和曝光过程。结果：该系统通过形象生动的操作画面,真实地模拟了程控X线机的工作原理和操作过程,使理论授课和实验教学达到完美融合。结论：对于其它医学仪器的虚拟设计,该方案具有重要的参考价值。     

北京万东程控500mA X线机ERR5故障检修

1故障现象 开机后,摄影床的手闸一档出现ERR5. 2故障分析 ERR5的含义为灯丝增温异常.该故障的形成原因主要应该包括以下部分. (1)灯丝板(4号板)异常该故障由主要包括以下几个可能.     

X光机双操作台的通信设计

目的:维修工作者在调试维修X线机的过程中通常存在一个麻烦:维修者在X线机机房内调试机器时每调节一次X线机曝光参数则需要往返一次控制室与机房。为了解决这个麻烦,提出了开发第二操作台并置于X线机房内的方案,以减少维修者往返控制室与机房的次数。方法:针对X671A型高频高压X光机设计了一个基于P89C669芯片的双操作台。第一操作台是一个实际的操作控制台,第二操作台为一台PC机。通过设定通信协议并调试软件,完成两个操作台的参数设置与显示、接收与发送命令等功能。结果:实现了机房和控制室各具有一个功能相同的操作台,使维修人员在机房内就可以通过使用第二操作台调节X线的曝光参数,从而调试维修X线机,极大方便了维修人员的工作。结论:对其它医学仪器的虚拟操作台设计,该方案具有重要的借鉴意义。     

西门子CompactL C形臂X射线机故障维修3例

本文主要介绍西门子SiremobilCompactLC形臂X射线机(简称C臂机)的故障分析及维修。1故障1故障现象:曝光没有图像、黑屏、无报错代码。故障分析及处理:初步分析故障存在于图像链部分,即CCD-信号线-图像工作站,拆开影像增强器外盖,可见CCD组件的电路板上有一根同轴电缆线,该电缆线是传输图像的信号线,经过C臂机身线缆插槽的BNC接口连接到图像工作站的Memoskop图像处理器背部VideoIN端口。     

基于PIC单片机的便携式X线机主控系统设计与实现

目的：配合已有的高压系统,以PICl8F8722为主控CPU设计了一套X线机的主控系统,实现便携式X线机的摄影功能。方法：以常规摄影用X线机的功能为基础,采用kV、mAs二个参数控制曝光过程,曝光容量3．5kW;采用64K串行EEPROM存储芯片,保存胖、中、瘦3种体位,每种体位20个人体部位的曝光条件,实现体位程序摄影;系统可选用中文或英文操作界面;9种出错报警显示出错代码和具体出错信息：可配备有线或遥控双手闸曝光。结果：该系统结合高压发生系统、成像装置构成的便携式X线机,能够实现曝光条件选择、曝光控制、曝光过程检测、出错报警等功能,具有体积小、自动化程度高、控制方便等优点;同时系统具备冷高压测试的软件功能,方便系统调试和维修;系统设计充分考虑主控系统的硬件应用环境,预留充分的功能通道,以满足系统升级或不同的高压系统对主控板的改进要求。结论：该系统为便携式X线机、移动式床旁X线机系统的实现提供一个有效的解决方案,也可成为现有X线机技术更新的可行方案。     

基于电路联动的X线机模拟操作装置研究

针对医学影像学和医学影像技术专业学生在步入工作岗位之前对X线机操作流程不熟悉,对X线机常规维修问题知之甚少等现状,设计了一种基于电路联动的X线机模拟操作装置,该装置以低廉的成本、较高的安全性能、无电离辐射等特点解决了以下实际问题:(1)通过该实验装置使无法接触到X线机的学生熟悉X线机透视/点片或摄影操作的基本流程,熟悉在透视/点片以及摄影操作过程中各个单元电路的作用、相互联系、工作原理以及各个关键继电器的工作状态;(2)通过故障点的设计,为学生日后从事X线机维修或操作工作打下坚实的基础。     

仿真工频X线机的研制

目的:研究、设计并制作一台教学使用的仿真工频X线机,解决教学过程中实验设备费用高、数量不足、机器占地面积大等缺点。方法:以经典F78-Ⅲ型X线机电路图作为仿真机电路设计蓝本,在满足教学要求的前提下对原型机功能和电路进行简化,对部分电路重新设计,元件采用平铺式裸露安装,方便学生观察元件的工作情况。结果:制作完成后的仿真X线机能够很好地仿真实际X线机的工作过程,教师可以借助仿真机对学生进行X线机基本工作原理的演示。结论:解决了教学设备不足的问题,并对设计其他仿真教学仪器有一定的借鉴意义。     

放射科X线机维护与保养的探讨

介绍如何通过积极开展X线机维护保养工作,确保医疗设备长期稳定地为临床服务.防微杜渐,及时发现并排除设备自身的故障隐患,落实积极主动的维护保养措施,减少了X线机等设备的维修费用,为医疗工作的顺利进行创造良好的设备环境.     

兰州地区464例遗传咨询病人的染色体分析

目的探讨染色体异常在遗传咨询病人中的发生情况.方法取受检者外周血进行淋巴细胞培养,常规收获制片,G显带处理,显微镜下进行核型分析.结果在464例病人中共检出染色体异常24例,染色体异常检出率为5.17%,其中平衡易位3例(12.5%),罗伯逊易位3例(12.5%),倒位5例(20.83%),性染色体异常8例(33.33%),染色体不平衡易位5例(20.83%).结论妇产科及生殖内分泌许多疾病与染色体异常有关,对这些病人进行染色体检查很有必要.     

Emery-Dreifuss muscular dystrophy: linkage to markers in distal Xq28.

Emery-Dreifuss muscular dystrophy (EMD) is characterised by (1) early contractures of the Achilles tendons, elbows, and postcervical muscles, (2) slowly progressive muscle wasting and weakness with a predominantly humeroperoneal distribution in the early stages, and (3) cardiomyopathy with conduction defects and risk of sudden death. Inheritance is usually X linked recessive but can be autosomal dominant. Family linkage studies have mapped X linked EMD to the distal long arm of the X chromosome but precise genetic localisation has been hampered by the rarity of this condition. We report three new families with X linked Emery-Dreifuss muscular dystrophy studied with DNA markers from Xq27-qter and three previously published families typed for additional markers. No recombination was observed with the red/green cone pigment locus, RGCP (lod score, Z = 2.46), the factor VIII coagulant gene locus, F8C (Z = 6.39), or with DXS115 (Z = 4.94). Two recombinants were observed which mapped EMD distal to DXS15 (DX13) and DXS52 (St14) respectively. Multipoint linkage analysis gave odds exceeding 200:1 for EMD being distal to these markers. A multipoint analysis incorporating published data gave the map cen-DXS304-9cM-DXS15-3cM-DXS52-2 cM-(RGCP,EMD)-3cM-F8C-2cM-DXS115 with odds of 120:1 in favour of a location for EMD between DXS52 and F8C as compared to the next best position distal to F8C.     

X linked neonatal myotubular myopathy: one recombination detected with four polymorphic DNA markers from Xq28.

A three generation family with X linked myotubular myopathy (MTM1) was studied with several polymorphic markers from the distal long arm of the X chromosome. A recombination between the disease gene and four markers (loci DXS52, DXS134, DXS15, F8C) from the Xq28 cluster was detected. A new polymorphic marker (U6.2) defining the locus DXS304 in the Xq27-28 region proximal to the Xq28 cluster did not show any recombination with MTM1. These results suggest the following order of loci in distal Xq: cen-DXS42-DXS105-(DXS304, MTM1)-(DXS52, DXS134, DXS15, F8C)-tel.     

颈项透明层增厚胎儿的临床结局分析

目的 研究颈项透明层(NT)增厚胎儿的临床结局,探讨超声测量NT厚度在评估胎儿预后中的临床价值.方法 对11～13+6周,头臀径为45～84 mm的4081例胎儿常规进行NT的测量,NT≥2.5 mm视为增厚,随访观察NT增厚胎儿的临床结局.将NT厚度分为4组(A组:2.5～3.4mm,B组:3.5～4.4mm,C组:4.5～5.4mm及D组:5.5～6.4mm),不同NT厚度胎儿的临床结局的比较采用Ridit分析,并应用等级相关分析NT增厚与胎儿健康存活率的相关性.结果 超声共检出58例NT增厚胎儿,其中6例NT≥6.5 mm,均于早孕期行人工流产终止妊娠,余52例NT＜6.5 mn,其中4例染色体异常,10例染色体正常但合并畸形或遗传综合征,1例中孕早期停止发育,33例至出生未见异常,4例失访.不同NT厚度胎儿的临床结局差异有统计学意义(P＜0.05),随NT增厚程度的增加,胎儿健康存活率呈降低的趋势[A组:81.8%(27/33),B组:62.5%(5/8),C组:25%(1/4),D组:0%(0/3),r=-0.993,P＜0.05].结论 超声测量NT厚度对于临床早期评价胎儿的预后有重要参考价值.     

Recombination between the factor VIII gene and the DXS52 locus gives the most probable genetic order as centromere-fra(X)-DXS15-DXS52-F8C-telomere

The linkage relationship between the factor VIII gene (F8C) and the DXS52 locus was examined in 8 families. Two recombinations were identified in 35 informative meioses (Zmax = 5.67; theta = 0.05), one in a family with hemophilia A, the other in a family with the fra(X) syndrome. Based on the latter recombination, the most probable order of loci was determined to be centromere-fra(X)-DXS15-DXS52-F8C-telomere. When these data are added to those reported previously the most probable genetic distance between F8C and DXS52 is 3 cM (Z = 14.62). Identification of these and other recombinations suggests that the use of DXS52 as a genetic marker for carrier detection and prenatal diagnosis of hemophilia A has an error rate between 3-5%.     

Effect of monovalent ions in glass ionomer on their uptake and re-release

AIMS: The study aims to directly measure uptake of Na and F ions by glass ionomer cement from dilute NaF solution and compare this with the subsequent re-release of these ions into water. In addition, the effect of the presence or absence of Na and/or F as a component of the glass is evaluated. MATERIALS AND METHODS: The four glass ionomers used differed only in glass composition; AH2 contained both Na and F, LG26 contained F, MP4 contained Na and LG30 contained neither Na nor F. Discs of cement were set in moulds at 37 degrees C for 1 h and matured in water at 37 degrees C for 3 days. Test discs were immersed in 0.2% NaF solution for 24 h, control discs in water. Discs were subsequently immersed in water which was changed regularly. Ion-selective electrode measurements (F and Na) and atomic absorption spectrometry (Na) were used to determine uptake (change in immersion solution concentration) and re-release into water. RESULTS: All cements took up large quantities of Na and F ions (range 95-336 mumol g-1). This resulted in internal ion concentrations from 16 to 56 times higher than the immersing solution. All re-release was complete within 97 days. No cement re-released more ion than taken up. Glass ionomers containing fluoride took up more Na and F than fluoride-free ones and then re-released a lower percentage of these ions. The cements all took up Na and F ions in equimolar proportions, but initially re-released more F than Na with F-free cement results tending to unity by 97 days. CONCLUSIONS: Glass ionomer cements take up Na and F ions from NaF solution in large quantities and in equimolar proportion. This is re-released either wholly or in part in 97 days by which time the release does not differ from the controls. The presence or absence of F in the cement composition markedly influences both uptake and re-release. Fluoride/hydroxyl interchange does not appear to play an important role in uptake.     

糖尿病患者交感神经皮肤反应及F波的观察

目的:探讨交感神经皮肤反应(SSR)及F波在糖尿病周围神经病中的诊断价值。方法:对30例糖尿病患者进行常规SSR及F波检测,并与30例正常人的检查结果进行对比分析。结果:与正常对照组比较,病例组上下肢SSR的潜伏期延长及波幅降低,差异有显著意义(P<0．01)。SSR的潜伏期异常率上肢为45％,下肢为75％,波幅异常率上肢70％,下肢75％,下肢异常率显著高于上肢。F波的异常率为45％(仅作上肢)。结论:SSR及F波检测是一种简单,易行和无创的自主神经功能及周围神经的检测方法,可作为糖尿病性神经损害的客观指标。     

Response, thermal regulatory threshold and thermal breakdown threshold of restrained RF-exposed mice at 905 MHz

The objective of this study was the determination of the thermal regulatory and the thermal breakdown thresholds for in-tube restrained B6C3F1 and NMRI mice exposed to radiofrequency electromagnetic fields at 905 MHz. Different levels of the whole-body averaged specific absorption rate (SAR = 0, 2, 5, 7.2, 10, 12.6 and 20 W kg(-1)) have been applied to the mice inside the 'Ferris Wheel' exposure setup at 22 +/- 2 degrees C and 30-70% humidity. The thermal responses were assessed by measurement of the rectal temperature prior, during and after the 2 h exposure session. For B6C3F1 mice, the thermal response was examined for three different weight groups (20 g, 24 g, 29 g), both genders and for pregnant mice. Additionally, NMRI mice with a weight of 36 g were investigated for an interstrain comparison. The thermal regulatory threshold of in-tube restrained mice was found at SAR levels between 2 W kg(-1) and 5 W kg(-1), whereas the breakdown of regulation was determined at 10.1 +/- 4.0 W kg(-1)(K = 2) for B6C3F1 mice and 7.7 +/- 1.6 W kg(-1)(K = 2) for NMRI mice. Based on a simplified power balance equation, the thresholds show a clear dependence upon the metabolic rate and weight. NMRI mice were more sensitive to thermal stress and respond at lower SAR values with regulation and breakdown. The presented data suggest that the thermal breakdown for in-tube restrained mice, whole-body exposed to radiofrequency fields, may occur at SAR levels of 6 W kg(-1)(K = 2) at laboratory conditions.     

Hemophilia A: genetic prediction and linkage studies in all available families in Finland

RFLP studies were done in 82 (75%) of all known hemophilia A families in the Finnish population (approximately 5 million). Two intragenic RFLPs (Bc1I/F8A, XbaI/p482.6) and two extragenic markers (TaqI/St14, Bg1II/DX13) were used. Among 263 females at risk, carriership could be evaluated with an intragenic marker in 47% and with an extragenic marker in 26%. In 27% of the females, carriership could be neither excluded nor confirmed; 68% of these females were relatives of an isolated patient. Eight recombinations between the factor VIII gene (F8C) and DXS52 (lod 25.02 at theta max 0.06), eight recombinations between F8C and DXS15 (lod 21.91 at theta max 0.05), and two recombinations between DXS52 and DXS15 (lod 33.56 at theta max 0.01) were found. Using multipoint linkage analysis, the most likely order of loci supported by the data was: F8C-DXS15-DXS52-DXS134. RFLP segregation analysis provides a highly useful method of carrier detection and prenatal diagnosis of hemophilia A, but its limitations must be carefully taken into account.     

Linkage in fragile X families of three distal flanking markers: ST14, DX13, and F8.

The use of linked DNA markers and linkage analysis in the fragile X [fra(X)] syndrome allows for improved genetic counseling and prenatal diagnosis. In order to provide the most accurate information, it is important to determine the order and location and position of flanking markers. Conflicting results have been reported for the order of 3 DNA markers distal to the fra(X) locus. We analyzed the linkage relationships of the distal markers ST14 (DXS52), DX13 (DXS15), and F8 (F8C) in 102 fra(X) families. The results indicated that the 3 DNA markers were closely linked to one another and mapped approximately 11 to 15% recombination units away from the fra(X) locus. The most likely order was fra(X)-DXS52-DXS15-F8. The order fra(X)-DXS52-F8 and 728 times more likely than the order fra(X)-F8-DXS52. One family showed a probable double recombinant: in one individual there was recombination between fra(X)-DXS52 and between DXS52-F8. The low probability of this occurring, 0.3%, raises the possibility of an alternate chromosome arrangement or an unusual recombinant mechanism in some individuals.