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

The Geonaute 360 with three outward facing lenses is designed to sit atop a helmet and record activity in every direction.

BBC: How tiny cameras have become big business

Boyden and Forest, working with Forest's graduate student Suhasa Kodandaramaiah, developed a robotic system to record activity of a single neuron in the living brain using a tiny glass tube.

CNN: Top brain scientist is 'philosopher at heart'

Use the credit card at least a couple of times a year and pay the bill online to show activity on your credit record.

WSJ: Getting Going: Managing Your Finances Abroad