超声技术名称简介

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                    <section><section powered-by="gulangu"><section><p><img src="image/20201019/85f30a9b666702bb4101533392db06ed_1.gif" /></p></section></section><section powered-by="gulangu"><section><section><p>显现帧频、成像帧频</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; 显像帧频取决于显示器，PAL制式为50HZ。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 成像帧频取决于成像设备的性能和探测深度，探测深度将对成像帧频起决定性影响，也与是否使用多声束形成等技术有关。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 当显像帧频远小于成像帧频时，在实时成像时，高的成像帧频不能提高时间分辨率等指标。</p></section></section></section><section powered-by="gulangu"><section><section><p>阵元</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;阵列式换能器的基本换能单元称为阵元。阵元在电气上有独有的引线，能直接激励而发射超声信号，也能接收回波而输出电信号。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;振子是由压电材料经高温烧结、电极化处理、打磨、加上电极等一系列加工后形成的压电元件。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;为了提高各个阵元的性能，常把一个阵元再切割为几个微元（振子）。</p></section></section></section><section powered-by="gulangu"><section><section><p>通道</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;对接收通道而言，所谓的物理通道是指具有接收隔离、前置放大、TGC（时间增益控制）控制等具体电路的硬件。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;在多声束形成器中，每一个物理通道（对应一个阵元）将分为多个虚拟通道（或称逻辑通道），产生不同的延迟时间与相邻的阵元信号相加，形成不同的声束。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 一般通道数不应大于阵元数。使用相控阵换能器的设备，通道数应等于阵元数，使用线阵或凸阵换能器的设备，通道数通常不超过阵元数的1/3，少数设备的通道数等于阵元数。</p></section></section></section><section powered-by="gulangu"><section><section><p>超声换能器</p></section><p><img src="image/20201019/18db1e3dcc50505b21035eb7641319cd_2.png" /></p> <section></section></section></section><section powered-by="gulangu"><section><section><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;超声换能器（超声探头）时超声诊断仪中最主要的部件之一。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;其功能是将电子线路产生的电激励信号转换成超声脉冲信号射入人体，并将人体组织产生的超声回波信号转换成接收的电信号。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;超声探头分为机械探头和电子探头。电子探头又分为线阵探头、凸阵探头、相控探头。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;凸阵探头中各个换能器小阵元排列成一条弧线，扇面成像，因此探测视野比较大。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 线阵探头中，换能器晶片被分割成许多小的阵元（如128或256），之间相互隔离，并排成一条直线。线阵探头可用于实时的B型成像和多普勒血流检测，缺点是探测的视野比较小。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;相控阵探头是电子探头，通常在1-2cm的长度上分布128阵元。通过控制相控阵探头每个阵元在发射和接收时的延迟时间，就可以实现声束偏转、电子聚焦等功能，从而进行扇扫。由于相控阵探头孔径小，常用于心血管系统的检测。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;常规探头阵元数为80、96、128阵元，而高密度 探头为256、512阵元。</p><p>&nbsp; &nbsp; &nbsp; &nbsp; 二维高密度探头：128*8阵元，及1024阵元。高密度多阵元探头使声束线密度高，多方向同时接收回声信号，不需要进行插补处理，图像细腻，分辨力好。</p></section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><section><p>欢</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>迎</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>关</p></section></section></section></section><section><section powered-by="gulangu"><section><section><p>注</p></section></section></section></section></section></section><section powered-by="gulangu"><section><section><p><br  /></p></section></section></section><section powered-by="gulangu"><section><section><section powered-by="gulangu"><section><p><img src="image/20201019/8685e7a278faffefe9c644d964b9f1df_6.jpg" /></p></section></section></section><section><section powered-by="gulangu"><section><section></section></section></section></section><section><section powered-by="gulangu"><section><section><p>关注我们</p><p>一起涨姿势！</p></section></section></section></section></section></section></section>