How do you make a nerve tester?

Question

the copper wire bent thing. I would like it to buzz? Do I use a door bell

Answer 1

The copper wire bent thing is just like a paper clip and the person reports the sensation.
A nerve tester that tests stimulous with computer timing is some thing that to be built with extreme care to avoid electrocution because things are being done under the skin where the resistance is much lower. In these, a pulse is applied and the response is tested down the limb.