Electro Magnetic Therapy early 1900s,

Based on Nikola Tesla's discovery that every disease in the body vibrates on a certain frequency, which then can be measured.

It's well documented that Tesla has never went to a doctor, as he was able to cure himself of any ailments.

These simple electric devices were able to kill the disease-causing bacteria and parasites by generating low-frequency waves of electromagnetic energy which enter the body, and targets the bacteria and parasites that cause ailments in the body.