A Method Detecting The Low Resistance Point of the SKin

Abstract

In the acupuncture clinic the method of selecting treatment points by measuring the electrical resistance of the skin has been widely used. It has become known that depending on the measuring period and the loaded voltage, the low resistance points of the skin are easily created, thus there remain many problems of the methods for measuring the skin resistance.
The present study was performed on the forearm skin of human subjects. For the measuring electrode an Ag-AgCl wire electrode with a diameter of 0.5mm was used. The electrode was fixed up to a FD-pick up (Nihon Kohden) and monitoring the pressure applied to the skin. A metal rod wrapped in a piece of gauze soaked with saline solution was used as the indifferent electrode. The skin resistance was calculated by measuring the current pass the both electrodes with a fixed resistance (10KΩ) Placed in series in the circuit when a square pulse (10msec, 4V) was appqied to the skin.
By used of the spuare pulse the low resistance points of the skin are stably detected when they are measured repeatedly. On the other hand, by of -DC 10 Volt, tce low resistance points gradually increase in number and lowering the resistance value by repeated measurerents. The sweat glands and hair follicle also show the low resistance value.
In conclusion, we could not distinguish the “true” low resistance points from sweat gland and other resistance destroyed points by measuring current clearly. But the square pulse method for measuring the skin resistance is useful to detect the low resistance point.