In the early 1950s, Reinhold Voll, a German medical doctor, developed an electronic testing device for finding acupuncture points electrically. He was successful in finding acupuncture points and demonstrating that these points, known to Chinese acupuncturists for millennia, had a different resistance to a tiny electrical current passed through the body, than did the adjacent tissues. Many other researchers have also verified that electrical conductance at the acupuncture points is significantly greater than the surrounding tissue.

Voll then began a lifelong search to identify correlations between disease states and changes in the electrical resistance of the various acupuncture points. He thought that if he could identify electrical changes in certain acupuncture points associated with certain diseases, then he might be able to identify those diseases more easily, or earlier, when treatment intervention was likely to be more effective. Voll was successful in identifying many acupuncture points related to specific conditions and published a great deal of information about using acupuncture points diagnostically. (Until Voll, these points had been used mainly for treatment). He found, for example, that patients with lung cancer had abnormal readings on the acupuncture points referred to as lung points. Changes also occurred in the electrical conductance of the acupuncture points supplying musculoskeletal structures that are inflamed. 

Voll discovered that certain acupuncture points showed abnormal readings when subjects were reacting allergically. He made several serendipitous discoveries related to “allergy” testing. He noted some unusual readings on certain acupuncture points when a patient had a bottle of medicine in his pocket. He could remove the bottle and consistently get different readings when the bottle was in his pocket compared to when it was not. At first he was baffled as to how a closed bottle of medicine outside the body could affect the acupuncture readings. It was even more baffling when he discovered that the glass bottle of medicine could change the readings when it was in contact anywhere along the closed electric circuit involved with the testing procedure.

Voll and his colleagues then began work to identify the nature of this strange phenomena. They inserted a metal plate into the circuit and demonstrated that many substances that prelude changes in acupuncture point readings when ingested could produce the same changes when placed on the plate (even in closed glass bottles). They assumed that there must be some kind of electro-magnetic energy being emitted from the substances, and that these energy fields somehow traveled along the electric circuit to the body (perhaps like the energy waves representing a person's voice travels along the electric circuitry of a telephone line).