Analysis of multifrequency impedance of biologic active points using a dry electrode system.

Objectives: A system is being developed for measurement of biologic active points (BAPs) in humans using a modified dry electrode. The BAPs measuring system analyzed the electrical characteristics and searched for the position of BAPs using modified dry electrodes.

Subjects: Skin electrical resistance at BAPs and non-BAPs was examined with a modified electrode system for healthy male subjects (ages 21-40). Four (4) acupuncture points of PC-4, PC-5, PC-6, and PC-7 on the left arms were chosen for BAPs. Bio-impedance was then conducted for BAPs and non-BAPS using a lock-in amplifier with a frequency range of 1 Hz-1 kHz.

Results: Resistances of four BAPs were found to decrease to about 29%-59% of non-BAPs and reactance of BAPs was found to decrease to about 23%-41% of non-BAPs. The difference in electrical impedance between BAPs and non-BAPs was easily recognized since the average value of BAPs was measured at lower values than that of non-BAPs. Through these experiments, BAPs could be distinguished from non-BAPs based on electrical impedance. In addition, the electrical impedance model used-the electrical BAPs model-appears to be better suited for skin.

Conclusions: The proposed BAPs electrical model of skin can be adapted for interpretation of changes in the impedance characterization of skin. This system would be used for various skin diagnoses due to the simplicity and reliability of bio-impedance analysis.