CB系列动态心电血压记录仪（CB-1304-C）

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                    <section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><section><svg viewbox="0 0 1 1"></svg></section></section><section><section powered-by="gulangu"><p><strong>明日复明日，明日何其多。</strong></p></section><section powered-by="gulangu"><p>○</p></section><section powered-by="gulangu"><p><strong>无畏的太阳</strong></p></section><section powered-by="gulangu"><p>○</p></section><section powered-by="gulangu"><p><span>医疗|学习|钻研|电子电路|原理</span><br  /></p></section></section><section><section><svg viewbox="0 0 1 1"></svg></section></section></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><p><img src="image/20201019/32752305fade7aaeba3bc98b53a0d134_1.jpg" /></p></section></section><section powered-by="gulangu"><p><strong>欢迎关注</strong></p></section></section><section><section powered-by="gulangu"><section><p><img src="image/20201019/32cfb2c307d2b4db6e952c689e6baae0_2.png" /></p></section></section><section powered-by="gulangu"><p><strong>好学医电在线</strong></p></section></section></section><section powered-by="gulangu"><p><strong>请留下你指尖的温度</strong></p><p><strong>让太阳拥抱你</strong></p><p><strong>记得这是一个有温度的公众号</strong></p></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><br  /></section></section></section><section><section powered-by="gulangu"><section><section><br  /></section></section></section></section><section><section powered-by="gulangu"><p><strong>CB系列动态心电血压记录仪（CB-1304-C）</strong></p></section></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><br  /></section></section></section></section></section></section><section><section powered-by="gulangu"><section><br  /></section></section></section></section></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><br  /></section></section></section><section><section powered-by="gulangu"><section><p><strong>故障现象</strong></p></section></section></section></section><section powered-by="gulangu"><p><strong>做完心电图后，将数据导出来电脑上，V6通道没有波形，其他通道波形正常。</strong></p><p><strong>多次重复测试故障依旧。</strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/baf8605a02271c425509128e0c0c39de_3.jpg" /></p></section></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><br  /></section></section></section><section><section powered-by="gulangu"><section><p><strong><span>分析过程</span></strong><br  /></p></section></section></section></section><section powered-by="gulangu"><p><strong>&nbsp; &nbsp; &nbsp; &nbsp;一、原理</strong></p><p><strong><span>心电信号形成以及传送过程的原理</span></strong></p><p><strong><span>来自人体体表微弱的心电信号（0.1-5mv之间），由10根心电导联线（RL,LL,LA,RA, V1, V2, V3, V4, V5, V6）传送到心电盒子里面。</span></strong></p><p><strong><span>经其内部一级（仪表放大器AD627）、二级（运放2336U）放大后并由处理器（C8051F020）分析、计算、处理，最后输出的心电信号（-0.5-1.5V之间），存储到SD卡上。</span></strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/ba16f85f7a99fa68c2ad1cbf5f384c35_4.jpg" /></p></section></section><section powered-by="gulangu"><section><p><img src="image/20201019/8acf580a7634a9da1ed2fcb6328e5bb1_5.jpg" /></p></section></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><p><strong><span>再经SD卡导出到电脑系统软件上面，以12道波形的形式（I, II, III, AVF, AVR, AVL, V1, V2, V3, V4, V5, V6）显示到显示屏上。</span></strong></p><p><strong><span>电路原理</span></strong></p></section><section powered-by="gulangu"><p><strong><span>来自人体微弱的心电信号（0.1-5mv），经导联线送至仪表放大器AD627芯片的输入端2脚和3脚（-in、+in），从仪表放大器AD627芯片的6脚（output）经滤波电容C1输出。</span></strong></p><p><strong><span>其中仪表放大器AD627芯片的4脚和7脚的2.2VDC由底下电源板提供，5脚的基准电压由电源板提供的2.2VDC经电容C2、电阻R4提供。</span></strong></p><p><strong><span>1脚和8脚可以接外置电阻来提高增益，该电路没有接外置电阻，增益由仪表放大器AD627芯片内部初始设定决定。</span></strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/821baad7d3a8b2054e6e6aa06e928009_6.png" /></p></section></section><section powered-by="gulangu"><p><strong><span>经仪表放大器AD627芯片作一级放大后的心电信号从6脚（output）经滤波电容C1输出到运算放大器2336U芯片的输入端3脚（+inA），2脚输入端（-inA）的信号由公共端导联线提供。</span></strong></p><p><strong><span>从运算放大器2336U芯片的1脚（outA）经滤波电容C6输出到运算放大器2336U芯片的输入端</span></strong><strong><span>6脚（-inB）,输入端5脚的信号由C8051F020芯片处理器提供。由运算放大器2336U芯片7脚（outB）输出二级放大后的心电信号。</span></strong></p><p><strong><span>最后将这8组经过一、二级放大后的心电信号，经接口板送至底下电源板上的C8051F020芯片处理器上，经其内部分析、处理、计算后，将心电信号储存到SD卡上。</span></strong></p></section><section powered-by="gulangu"><p><strong><span>心电导联线的定义</span></strong></p><p><strong><span>心电图12导联分别是：</span></strong><strong><span>美标：I, II, III, AVF, AVR,AVL, V1, V2, V3, V4, V5, V6</span></strong></p><p><strong><span>欧标：I, II, III, AVF, AVR, AVL, C1, C2, C3, C4, C5, C6</span></strong></p><p><strong><span>心电图导联线的设计是10根导联线（RL,LL,LA,RA, V1, V2, V3, V4, V5, V6），其中4条线接在肢体上，RA（右手腕）、LA（左手腕）、RL(右脚）、LL（左脚）。</span></strong></p><p><strong><span>而其中RL(右脚）只是起到中性接地左右，所以三肢各一个。RA, LA, LL 测出的I, II, III。AVF, AVR, AVL测的是你的心脏是不是在正确的位置，心尖是不是在左下方30度角的位置。</span></strong></p><p><strong><span>I, II, III是荷兰医生、生理学家威廉·埃因托芬（心电图之父)的发明，AVF, AVR, AVL是他的后人（忘记名字，是美国人）在埃因托芬的基础上发明了另一种方法确认心脏的位置是否正确的公式。</span></strong></p><p><strong><span>所以在心电图机上，AVR的波形跟II是一样的。在图里打出来12个导联的图形都齐全。</span></strong></p><p><span><strong>二、分析</strong></span></p><p><span><strong>根据故障现象V6通道没有输出，其他通道正常，说明8个通道之间，存在一个通道，没有输出。</strong></span></p><p><span><strong>可以初步排除处理器C8051F020芯片，SD卡，电池。</strong></span></p><p><span><strong>将故障锁定在以下：①V6通道对应的两个放大芯片是否损坏。</strong></span></p><p><span><strong>②V6通道芯片外围电路是否存在坏件。</strong></span></p><p><span><strong>③V6通道芯片之间，芯片与处理器之间的连接线是否存在断路。</strong></span></p></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><br  /></section></section></section><section><section powered-by="gulangu"><section><p><strong>解决方法</strong></p></section></section></section></section><section powered-by="gulangu"><p><strong>由简入繁，首先通过蜂鸣档找到V6导联对应的仪表放大器AD627芯片，以及与之对应的运算放大器2336U芯片。</strong></p><p><strong>通过检测它们之间输入端与输出端之间的通断情况，发现从运算放大器2336U芯片输出端7脚（outB）出来到处理器C8051F020芯片输入端30脚之间存在虚焊，补焊后，试机故障依旧。</strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/85c8a8e4e223a11b0ed65a263e048351_7.jpg" /></p></section></section><section powered-by="gulangu"><p><strong>以上工作排除③，接下来示波器检测仪表放大器AD627芯片的6脚输出端（output）波形，峰值5.2mv左右，还有波形均正常。</strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/33ff768236954d65b757c1128c6b43a8_8.jpg" /></p></section></section><section powered-by="gulangu"><p><strong>检测运算放大器2336U芯片输出端7脚（outB）波形，波形呈直线，没有清楚的呈现心电波形的特征，初步怀疑芯片损坏。</strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/b0b5a30c36d5d6357fadbfc3851c7b4b_9.jpg" /></p></section></section><section powered-by="gulangu"><p><strong>对调隔壁通道运算放大器2336U芯片，上机测试，故障发生转移，变成I通道没有波形，确认2336U芯片损坏，更换后已经修复。</strong></p></section><section powered-by="gulangu"><section><p><img src="image/20201019/e5757d3751dd90a76b83784d6ab6ac7d_10.jpg" /></p></section></section><section powered-by="gulangu"><section><p><img src="image/20201019/e0c1cee8838049eccaea5b7a11516937_11.jpg" /></p></section></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><p>欢</p></section></section></section><section><section powered-by="gulangu"><section><p>迎</p></section></section></section><section><section powered-by="gulangu"><section><p>关</p></section></section></section><section><section powered-by="gulangu"><section><p>注</p></section></section></section></section><section powered-by="gulangu"><p><br  /></p></section><section powered-by="gulangu"><section><section powered-by="gulangu"><section><p><img src="image/20201019/32752305fade7aaeba3bc98b53a0d134_1.jpg" /></p></section></section></section><section><section powered-by="gulangu"><section><section><br  /></section></section></section></section><section><section powered-by="gulangu"><p>好学医电在线</p><p>和他的朋友们</p></section></section></section></section>