心电图机原理与维修

心电图机原理与维修 心电图机的原理与维修 结构与原理 1 输入电路由电极板 、导联线 、导联选择开关 、高频滤波电路等组成 。作用:减少干扰 、选择导联,将人 体各部分信号引到前置放大器 。 1. 1. 1 导联线作用是将电极板上获得的心电信号送到放大器的输入端 ，它是一条五芯(或多芯)的带金属屏蔽网的绞合线 。 要求 对教师党员的评价套管和固井爆破片与爆破装置仓库管理基本要求三甲医院都需要复审吗 线柔软 、接头处牢靠 。屏蔽网的作用是防止外界电磁波的干扰 。屏蔽网通常接地 , 导联线常有五芯 、七芯和十三芯三种。 1. 1. 2 导联选择开关作用是不改变人体电极连接线 ,用来改变各导联线和心电放大器之间的连接方法,用来记录某一导联的心电图。一般有三种开关: 圆形波段开关,琴键开关 ,触摸开关 。 1. 1. 3 高频滤波电路作用是滤去不需要的高频信号,减少高频干扰 。一般由RC低通滤波电路组成 。 1. 2 心电放大电路 这是心电图机的核心作用是放大心电信号推动记录器工作它由前置放大电路电压放大电路和功率放大电路组成 。 1. 2. 1 前置放大电路作用是把微弱的变化缓慢的心电信 号放大到足以推动电压放大电路,同时又有足够抑制各种干 扰信号的能力。主要包括前置放大器、1mV定标发生器、时 间常数电路等。 1. 2. 2 电压放大电路作用是将前置放大器放大输出仅 20mV的心电信号进一步放大输送到后置放大器。它由直流 电压放大器、增益调节电路、基线调节电路、封闭电路、双T型 滤波电路及肌电干扰抑制电路组成。 1. 2. 3 功率放大电路作用是将电压信号变换为大的电流 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 和功率去推动记录器工作。常采用对称式互补射极输出器单 端推挽电路。 1. 3 心电记录器作用是把心电信号转换成机械运动的装 置。它由记录器表头、描笔等组成。心电信号经心电图机导 联选择以及心电放大器放大后,驱动记录器上的转轴,使之转 角随心电信号变化而变化,在转轴上固定一支记录笔,笔也随 之偏转,从而在记录纸上描出随时间变化的心电图曲线。 1. 4 电动机走纸电路它的作用是使记录纸按要求随时间 作“匀速”运动,使记录下来的心电波形的时间呈线性。包括 走纸传动装置(一个微型电动机直流电动机或交流电动 机)、控制电路和走纸机构部分。走纸速度一般为25mm/s 和 50 mm/s 两种。两种速度可以通过倒换快慢齿轮来实现。 国内一般按照记录器同步输出道数分为:单道、三道、六道和十二道心电图机等。[1]组成部分 1、输入部分 2、放大部分 3、控制电路 4、显示部分 5、记录部分 6、电源部分 重要 参数 转速和进给参数表a氧化沟运行参数高温蒸汽处理医疗废物pid参数自整定算法口腔医院集中消毒供应 1、输入电阻 即前级放大器的输入电阻。输入电阻越大，因电极接触电阻不同而引起的波形失真越小，共模抑制比越高。一般要求大于2MΩ，国际上大于50MΩ。 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 2、共模抑制比 心电图机一般采用差动式放大电路，这种电路对于同相(又称共模信号，例如周围的电磁场所产生的干扰信号)有抑制作用，对异相信号(又称差模信号，需采集的心电信号就是差模信号)有放大作用。共模抑制比(CMRR)，指心电图机的差模信号(心电信号)放大倍数Ad与共模信号(干扰和噪声)放大倍数Ac之比，表示抗干扰能力的大小。要求大于80dB，国际上大于100dB。 3、抗极化电压 皮肤和表面电极之间会因极化而产生极化电压。这主要是由于心动电流流过后形成的电压滞留现象，极化电压对心电图测量的影响很大，会产生基线漂移等现象。极化电压最高时时可达数十毫伏乃至上百毫伏。处理不好极化电压，产生的干扰将是很严重的。 尽管心电图机使用的电极已经采用了特殊材料，但是由于温度的变化以及电场和磁场的影响，电极仍产生极化电压，一般为200,300mV，这样就要求心电图机要有一个耐极化电压的放大器和记录装置。要求大于300mV，国际上大于500mV。 4、灵敏度 是指输入1mV标准电压时，记录波形的幅度。通常用mm/mV表示，它反映了整机放大器放大倍数的大小。心电图机标准灵敏度为10mm/mV。规定标准灵敏度的目的是为了便于对各种心电图进行比较。 5、内部噪声 是指心电图机内部元器件工作时，由于电子热运动产生的噪声，而不是因使用不当外来干扰形成的噪声，这种噪声使心电图机没有输入信号时仍有微小的杂乱波输出，这种噪声如果过大，不但影响图形美观，而且还影响心电波的正常性，因此要求噪声越小越好，在描记曲线中应看不到噪声波形。噪声大小可以用折合到输入端的作用大小来计算，一般要求低于输入端加入几微伏至几十微伏以下信号的作用。国际上规定?10μV。 6、时间常数 在直流输入时，心电图机描记出的信号幅度将随时间的增加而逐渐减小，输出幅度自100%下降至37%左右所需的时间。一般要求大于3.2s，若过小，幅值下降的过快，甚至会使输入的方波信号变成尖波信号，这就不能反映心电波形的真实情况。 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 7、频率响应 人体心电波形并不是单一频率的，而是可以分解成不同频率、不同比例的正弦波成分，也就是说心电信号含有丰富的高次谐波。若心电图机对不同频率的信号有相同的增益，则描记出来的波形就不会失真。但是放大器对不同频率的信号的放大能力并不一定完全一样的。心电图机输入相同幅值、不同频率的信号时，其输出信号幅度随频率变化的关系称为频率响应特性。心电图机的频率响应特性主要取决于放大器和记录器的频率响应特性。频率响应越宽越好，一般心电图机的放大器比较容易满足要求，而记录器是决定频率响应的主要因素。一般要求在0.05~150Hz(-3dB)。 8、绝缘性 为了保证医务人员和患者的安全，心电图机应具有良好的绝缘性。绝缘性常用电源对机壳的电阻来表示，有时也用机壳的漏电流表示。一般要求电源对机壳的绝缘电阻不小于20MΩ，或漏电流应小于100μA。为此，心电图机通常采用“浮地技术”。 9、安全性 心电图机是与人体直接连接的电子设备,必须十分注意其对人体的安全性。从安全方面考虑,心电图机可分属三型:B型、BF型和CF型(详见中华人民共和国国家标准GB10793-89心电图机和使用安全要求)。根据国际电工技术委员会(IEC)通则中规定: 医用电器设备与患者直接连接部分叫"应用部分"。为了进一步保证患者安全,医用电器设备的应用部分往往也加有隔离措施、光电偶合、电磁波偶合等。根据应用部分的隔离程度,医用电器设备的应用部分往往也加有隔离措施、光电偶合、电磁波偶合等。 根据应用部分的隔离程度,医用电器设备分为B、BF、和CF型。 B型: 应用部分没有隔离。 BF型: 应用部分浮地隔离,可用于体外和体内,但不能直接用于心脏。 CF型: 应用浮地隔离,对电击有高度防护,可直接用于心脏。 分类 心电图机分类 心脏是人体血液循环的动力装置。正是由于心脏自动不断地进行有节奏的收缩和舒张活动，才使得血液在封闭的循环系统中不停地流动，使生命得以维持。心脏在搏动前后，心肌发生激动。在激动过程中，会产生微弱的生物电流。这样，心脏的每一个心动周期均伴随着生物电变化。这种生物电变化可传达到身体表面的各个部位。由于身体各部分组织不同，距心脏的距离不同，心电信号在身体不同的部位所表现出的电hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 位也不同。对正常心脏来说，这种生物电变化的方向、频率、强度是有规律的。若通过电极将体表不同部位的电信号检测出来，再用放大器加以放大，并用记录器描记下来，就可得到心电图形。医生根据所记录的心电图波形的形态、波幅大小以及各波之间的相对时间关系，再与正常心电图相比较，便能诊断出心脏疾病。诸如心电节律不齐、心肌梗塞、期前收缩、高血压、心脏异位搏动等。 一、心电图机的分类 心电图机有不同的分类方法。如: (一)按机器功能分类 心电图机按照机器的功能可分为图形描记普通式心电图机(模拟式心电图机)和图形描记与 分析 定性数据统计分析pdf销售业绩分析模板建筑结构震害分析销售进度分析表京东商城竞争战略分析 诊断功能心电图机(数字式智能化心电图机)。 (二)按记录器的分类 记录器是心电图机的描记元件。对模拟式心电图机来说，早期使用的记录器多为盘状弹簧为回零力矩的动圈式记录器，九十年代之后多用位置反馈记录器。对数字式心电图机来说，记录器为热敏式或点阵式打印机。 1、动圈式记录器:动圈式记录器的结构原理是由磁钢组成的固定磁路和可转动的线圈。心电图机功率放大器的输出信号加到记录器的线圈上，线圈上固定有记录笔。在有心电信号输出时，功率放大器向线圈输出电流，线圈转动。当线圈的偏转角度与盘状弹簧的回零力矩相同时，停上偏转。这样，线圈带动的记录笔便在记录纸上描记出心电图波形。 2、位置反馈记录器:位置反馈记录器是一种不用机械回零弹簧的记录器，特殊的电子电路可起到回零弹簧的作用。机器断电时，位置反馈记录器的记录笔可任意拨动。 3、点阵热敏式记录器:热敏式记录器是利用加热烧结在陶瓷基片上的半导体加热点，在遇热显色的热敏纸上烫出图形及字符的。 (三)按供电方式分类 按供电方式来分，可分为直流式、交流式和交、直两用式心电图机。其中，交、直两用式居多。直流供电式多使用充电电池进行供电。交流供电式是采用交流-直流转换电路，先将交流变为直流，再经高稳定的稳压电路稳定后，供给心电图机工作。 (四)按一次可记录的信号导数来分 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 按一次可记录的信号导数来分，心电图分为单导及多导式(如三导、六导、十二导)。单导心电图机的心电信号放大通道只有一路，各导联的心电波形要逐个描记。即它不能反映同一时刻各导心电的变化。多导心电图机的放大通道有多路，如六导心电图机就有六路放大器，可反映某一时刻六个导联的心电信号同时变化情况。 (五) 使用说明 1(电源开关置于“ON”。 2(电源开关置于“AC(交流)，’，此时“LINE”“TBST”“PA PER SPEED(25mm/s)”“SENSITIVITY(l)”“STOP”，晶体灯发出亮光。 3(调节基线控制旅钮应能改变描笔的位置，使之停在纪录纸中央附近。 4(按动“CHECK”键，此时“STOp”灯灭，“CHECK”灯亮。 5(按动定标键“ lmV”，使描笔随着定标键的按动而作相应的摆动。 6(按“START”，此时“CHECK”灯灭，“START”灯亮，记录纸按25mm/sec速度走动。 7(继续按动定标键，在走动的纪录纸上可看到一清晰的定标方波，其振幅应是10mm。 8(按动“LEAD SELECTOR”键，使之由“TEST”向“I”导“?”联转换。 9(在心电图纸上得到一段清晰的纪录后，可继续按动“LEAD SELECTOR”键，使之由“I”导联向“?”导联转换，以此类推，可重复上述操作，完成12个导联的心电图纪录。 10(仪器使用完毕，切断电源，做好清洁工作。并做好仪器使用登记。 常规保养 心电图机应定期进行维护和保养，以延长心电图机及其各个部件的寿命。具体要求如下。 1每天作完心电图描记后，应保持电极清洁。铜合金制成的电极如果出现锈斑，可用细砂纸擦掉锈斑后，再用生理盐水浸泡一夜，使其表面形成性能稳定的薄膜。镀银的电极则用水洗净擦干即可，避免擦伤镀银层。 导联电缆的芯线或屏蔽容易折断损坏，特别是靠近两端的接头处，切忌用力牵拉或扭曲，收藏时应盘成直径较大的圆环或悬挂，避免过度扭曲或锐角折叠。 1.3 交直流两用的心电图机，应按说明及时充电，以延长电池使用寿命。 1.4 心电图机应避免高温、日晒、受潮、尘土或撞击，用毕盖好防尘罩。 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 1.5 每半年打开机盖进行除尘、去湿和进行检查。 及时清除电路板中的灰尘，保证机器内部干燥，避免因为潮湿或者灰尘造成短路，损坏电路板。 1.6 由医疗仪器维修部门定期检测心电图机的性能。热笔记录式心电图机应根据记录纸的热敏感性和走纸速度，调整热笔的压力和温度。心电图机在使用中经常出现伪差干扰故障，严重时会影响心电图的正常描记，应及时排查。 常见故障及排除 在日常使用心电图机时，经常出现热笔描记图形过粗或过细、干扰、基线漂移过大、阻尼不正常等故障，严重影响心电图机使用，产生原因和排除方法归纳如下。 1描记图形过粗或过细 产生原因:温度过高或过低。 排除方法:调整热笔温度，调节电位器使热电笔温度适当即可。 2干扰 在心电图机走纸记录时，心电图上叠加有一定幅度和有规律的正弦波或叠加一种无规律的毛刺，即为干扰 医学教 育网收集整理 。分为以下几种: (1)导联开关置“0”位时有干扰 医学教 育网收集整理 首先，判断干扰是50Hz还是低频。如果是50Hz干扰一般为导联输入部分有断线、脱焊现象，即导联线断线;导联开关到放大板的输入线插头座断脚、脱焊或接线断。如果表现为低频干扰，则首先检查电刷上刷毛是否齐整;是否与不该接触处有电气接触，然后，再检查电机线圈是否有断线。 (2)工作时有干扰 导联线断、隐断或漏电均可引起干扰。但一般因导联线断，引起的干扰表现为只有在相关导联状态时才会引入干扰。最简单也最彻底的办法是更换导联线，但如果有修复价值的最好从断处或漏电处剪开后，再重新焊接。导联开关接触不良、接线断线、脱焊等均会引入干扰。记录器或热笔线圈与机壳接触也可能引入干扰。 (3)其他干扰 电源纹波过大、滤波电容损坏，内部应该接地处未接好，内部走线不合理或屏蔽不良等都可引入干扰。 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 3基线漂移 导联开关在“0”位时，记录器描绘的基线不水平而有缓慢上升或下降，即为基线漂移。 排除方法:用酒精擦拭放大板上各插头、插座，以防有漏电现象。待完全干燥后，观察基线漂移是否仍然过大。随后检查前置放大器与电压放大器之间耦合电容是否漏电。然后，再检查封闭继电器电路。用线路分割法，断开封闭继电器电路，如漂移达到标准要求，则故障为封闭继电器损坏或漏电，应更换。最后，检查场效应管。先用替代法，以同型号场效应管分别替换前级场效应管。如故障消除则前级中某一只场效应管(或两只)输入电阻不稳，应更换。 但必须用两只各项参数均比较接近的场效应管将原来两只都换下，否则，若场效应管不对称，对心电图机其他指标将有很大影响。如漂移仍然过大。一般为后级场效应管某只输入电阻不稳定，同法替换即可。 4阻尼不正 (1)描1mV定标电压波形时，波形无上冲且有圆角即为阻尼过大。排除方法:调整阻尼调节电位器使阻尼适中。 (2)描1mV定标电压波形时波形上冲过大，即为阻尼过小。排除方法: 调整阻尼调节电位器使阻尼适中。若阻尼过小且不可调整时，先检查阻尼调节电位器是否脱焊，损坏或接触不良。如果损坏则应予更换。如未损坏，则故障为记录失磁造成，应更换记录器或重新上磁。 (3)如果阻尼不均匀，一般为热笔放置不平，热笔定位夹与导轨间有较大间隙，调整时，予以调整。 心电图机是比较精密的仪器，使用时应避开潮湿、震动、强电场、磁场等场所，心电图室应尽量远离X线室、理疗室、电梯等以减少和避免干扰。 5镐镍电池充不上电或者充电时电池发热 心电图机的电源多采用220v市电供电,或干电池、蓄电池直流电源供电,也可采用交直流两用方式供电。 故障诊断方式:镐镍电池是一种可反复充电的电池,一般可充放3 ,5 次,额定电压为 5V,终端电压 V,出现无法充电的原因如下?充电电路的输出开关1 :未放在充电位置。?电池组的引线脱落。?充电次数已达到 额定的次数、电池已失效。?电池组的一只或几只电池已变 质。?充电电路有故障。?机内电源电路有问题。 保险丝烧断 ?变压器的初级线圈中有的因绝缘不 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 好引起短路。?机内电源有短路。?稳压电路中大功率的的 调整管对地绝缘不良或短路。 (1)电池老化或损坏，更换电池后心电图机可充放电使用。即交直流状态下仍可正常工作。 (2)充电电路板故障，电池充不上电常常伴随待机状态下充电指示灯常亮不闪烁，电池发热。导致外部交流电停止供应的情况下开机显示电量不足或者开不了机。将电池取下后换到新的心电图机上电池可充电工作或者换上新电池后心电图机仍然不给电池充电，说明充电电路有故障，需更换充电电路板。 6 描笔移动范围小 描笔移动范围不符合略大于40mm的要求,其原因有以下几点: ?心电图机处于工作状态时,热笔不在记录纸的中心线上。可松动笔架与记录器轴的固定螺丝,重新对准零位拧紧螺丝,并注意笔架高低位置合适。?热笔幅度限制器档板宽度不够,或热笔加热器的两根引线安放不适限制了热笔的位移。此时可适当放宽档板角度或调整热笔加热引线的位置。?记录器有故障也可以引起热笔移位幅度减小,当确认记录器有故障时,只有更换新记录器。?放大器有故障是引起热笔移动范围减小的主要原因。这种现象是电压放大器部分有故障。此时应检查电压放大器的晶体管的管脚有无断脚或虚焊,电阻和电容断线或虚焊,重新焊接好断线和虚焊点,重新调整电压放大器的工作点。 7 波形失真记录的心电图波形严重变形,原因可能有:?阻尼调节不当或阻尼电路有故障。?记录器线性差(位置反馈电路线性差)。?阻容耦合电容变质,引起时间常数变小。?肌电干扰抑制网路和50Hz抑制网路的元件变质。?输入平衡电阻脱落、隐断或电阻变质。?电压放大器和功率放大器的工作点调整不合适。?走纸推动装置有故障,引起走纸速度误差过大。 8 无定标或定标电压大小不合适可能原因有: ?标准电池耗尽,无电压。?1mV定标开关失灵。?定标电路的连接线脱落,分压电阻变质。?机内稳压定标电路有故障。?定标光电耦合隔离电路有故障。?封闭电路的继电器或开关管闭合,放大器的后级被封闭。?导联选择开关有故障或连接线脱落。?放大器的工作点严重不正常。?记录器线圈损坏或盘香弹簧脱落、位置反馈电路有故障。 9 “封闭”失灵闭锁 (stop或inst)电路在作心电图时不能起封闭作用,原因有: ?封闭电路或继电器有故障。?自动封闭电路或封闭开关管有问题。?封闭控制开关损坏。 10 热笔单偏 出现热笔单偏的现象基本上是机内发生故障,其原因有: ?两个耦合电容器有一个漏电。?电压放大器或功率放大器中的一侧放大管损坏。?基线调节电位器损坏或一侧连线断开。?放大器的工作点严重不平衡。?热笔的机械零位不对。 11 热笔不热 心电图机工作状态,按1mV定标,走纸热笔不热,出现这种现象原因如下: ?笔温加热电路有问题,笔温加热振荡电路不工作。?笔温调节器有问题。?供电电源有问题。 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with 12电动机不转或纸速不准 心电图机工作状态,开动记录开关,电动机不转。出现这种故障的原因有: ?电动机的线圈开路或短路。?电动机的转子卡死。?电动机的移相电容变质。?纸速控制电路故障。?纸速调节器的连接线脱落或虚焊。?走纸轴和电动机的传动轴松动。?传动齿轮咬合不当,齿轮受损、弹簧头磨损。 13走纸机械故障 走纸机械故障有以下几种现象和原因: ?走纸时噪声大。产生这种现象的原因是各组合齿轮间或轴与轴承间有脏物或缺少润滑油。?走纸时记录纸偏向一边并卷边。严重时甚至拉破记录纸。产生这种现象的原因是热笔定位架不平,在高的一面引起记录纸卷边或热笔定位架某一边没有靠导轨与导轨间有较大的缝隙。?记录纸在描记时,一边紧一边松相差太大,影响描记。这是由于托轴弹簧架力不匀或热笔定位架两边高低不平。 hot standby mode, ensure that the rehabilitation centre 7*24 hours/normal, secure network working condition. network outlet is equipped with a firewall. Guarantees stable and secure operation of the network. According to the star-shaped structure of computer networks to achieve medical ground floor second floor access layer switches to ground five layer Interconnect as well as rehabilitation, 1, 2nd floor access layer switch interconnect. Network route 12-core single-mode fiber-optic cable through a weak pipeline laying perpendicular to the shaft from the FD to the device of floors of BD. 48 data points corresponding to each pair of optical fiber intranet, Internet 24 data points, and fully reserve standby, rehabilitation center for future facility expansion needs. convenient and economical. Internet medical room as core telecommunication line, the four-storey information directly into a layer of weak lines, with 1 large Gigabit switch as the core of Internet System. meet the rehab hospital-wide Internet applications, data exchange and social access, public information release. Together, access switch selection based on fast, load power, security and stability, business integration, ease of management and maintenance of equipment basic conditions to meet hospital-wide data exchange, to provide users with access to multiple business, Exchange and integration of secure network. Network outlet is equipped with