Dermatron

The Dermatron is an electronic device that measures electrodermal activity, first devised by German physician Reinhold Voll as a diagnostic instrument for use in a system referred to as Electro-Acupuncture According to Voll (EAV). The subject holds the negative electrode in one hand, while the diagnostician uses a positive electrode probe to take electrical resistance measurements at meridians, the points defined in systems of acupuncture as connected to organs of the body, in order to diagnose any disorders of the subject on the basis of its readings. It has also been claimed that the device allows a diagnostician to determine any beneficial or harmful effects that substances would have on a subject by introducing such substances to the circuit.