If a heart beats too slowly, the device will use electrical signals to help set a normal rate.

VOA: special.2010.06.29

Because it's a gel electricity is going to move through the gel because there are ions in it the same way - for the same reason you don't drop an electrical device into the bathtub because charge moves through water that has ions in it.

由于凝胶中存在离子,电流会通过凝胶,同样--,因为同样的原因你不会把电器扔进浴缸里,因为水里也有离子,所以水可以导电

耶鲁公开课 - 生物医学工程探索课程节选

As time goes on, we've developed ever more complex machines to study people and we've talked about some of these already: EKG machines, so an example of an electrical device that can be used to monitor a very elaborate function deep inside your body, the beating of your heart and the rhythm of your heart.

如今,我们已经有功能更加复杂的设备,来研究人类,比如之前说到的心电图,我们使用电子装置,对身体内部机能进行精确地监控,具体到心电图就是心跳和心率

耶鲁公开课 - 生物医学工程探索课程节选