In 1950, Dr. Yoshito Nakatani, M.D., Ph.D. has discovered that in patients with nephritis, kidney meridian had an increased electrical conductivity. However, he was not able to find the same phenomenon in healthy patients. Further research showed that this is true for other organ groups and corresponding acupuncture meridians. He named these lines “ryodoraku” (ryo-good, do-electro conductive, raku-line) and, depending on where they started, called them, either H1-H6 (hands) or F1-F6 (feet). These names are used interchangeably with the classical meridian names. E.g. H1 is the lung meridian, H2 is the pericardium, etc.
Later it was also discovered, that in other cases the meridians had poor conductivity. These values showed a correlation with symptoms, displayed by the patient. This resulted in a variety of data charts.
This method has been developed further and improved significantly since the 1950’s. Currently, acupuncture practitioners, using Nakatani’s technique, can draw detailed conclusions about the patient’s diagnosis and the best course of treatment.