Rather than by forming an image or a picture you put electrodes on the surface of the body and measure the electrical potential as a function of position on the body.

它并不对人进行直接的造影,而是将电极放到身体表面,通过测量该位置电势能,表征该部位的生理状态

耶鲁公开课 - 生物医学工程探索课程节选

If you put the electrodes in the right position and you measure in the right way you can detect the electrical activity of the heart and record it on a strip recorder like this one shown here, or display it on a computer.

如果将电极放置正确,并采用正确的方式检测,就能检测到心脏的电活动,并将它记录在像这样的长图记录仪上,或者显示在电脑上

耶鲁公开课 - 生物医学工程探索课程节选