In the 1950s the German doctor Reinhold Voll discovered that "electrical energy" was distributed on the inside and outside of cells. He then designed a simple electrical circuit and was able to measure the changes in energy within the human body.
1950 年代，德國醫師傅爾發現人體有「電能」分佈在細胞的內外之間，於是設計了一個簡單的電流迴路，測出人體電能的變化。