BS ISO 20495:2018 pdf download – Traditional Chinese medicine — Skin electrical resistance measurement devices
This document specifies performance and test methods for skin electrical resistancemeasurement devices.
This document is applicable to skin electrical resistance measurement devices through which anelectrical signal is applied on acupuncture points of the human body or specific points of the bodysurface in a non-invasive way so as to detect the resistance of the body.
This document is not applicable to software or functions for medical analysis of the test results.Additional guidance and rationale are given in Annex A.
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies.Forundated references, the latest edition of the referenced document(including any amendments) applies.ISO 10993-1,Biological evaluation of medical devices — Part 1:Evaluation and testing within a riskmanagement process
IEC 60601-1,Medical electric equipment – Part 1: General requirements for basic safety andessential performance
IEC 60601-1-2,Medical electric equipment — Part 1-2: General requirements for basic safety and essentialperformance —Collateral standard: Electromagnetic compatibility —Requirements and tests
3Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and lEC maintain terminological databases for use in standardization at the following addresses:
ISO online browsing platform: available at http:/ /
IEC Electropedia: available at
skin electrical resistance
direct current(DC) resistance value or alternating current (AC) resistance value between acupuncturepoints on the skin surface of the patient (or specific points) and a reference point of the skin surface(point on the skin in contact with auxiliary electrode)
skin electrical resistance measurement device
device that can detect electrical resistance on acupuncture points or specific points of the body surfaceunder the condition of electrical signals being applied to the human body
detection electrical signal
voltage signal or current signal on device or for match use applied to patient for electricalresistance detection
auxiliary electrode
electrode that is fixed on specific points of the patient (e.g. hand-held or fixed on palm or forehead) forreference use, which is relatively fixed during detection
exploratory electrode
electrode that directly contacts acupuncture points or specific points of the patient’s body surface,constituting a pair of electrodes with an auxiliary electrode for resistance detection
detection voltage
root mean square (RMS) of maximum open-circuit voltage between the auxiliary electrode and theexploratory electrode in the detection electrical signal
detection current
RMS of maximum current between the auxiliary electrode and the exploratory electrode in detection ofthe electrical signal
electrode force indication device
device on the exploratory electrode or auxiliary electrode whose function is to control or display theapplied force during detection, including an exploratory electrode with force switch
force sensing switch of exploratory electrode
switch mounted in the exploratory electrode to reduce the error of detection result during use3.10
effective dimension of electrode
accessible part that has electrical energy transmitting to the patient during detection of auxiliaryelectrode and exploratory electrode
4 Technical requirements
4.1 Measurable range
The skin electrical resistance measurement device shall be capable of measuring skin electricalresistance between 100 Q and 10 K Q.
Conformity inspection of technical documentation is provided by the manufacturer.For the accuracy of measurable value, see A.3.
4.2Accuracy of measurement
The error between any measured value and actual value shall be no more than ±10 %.The measuredvalue may be expressed as electrical resistance ([Q), voltage (V),current (A) or a relative value.
Conformity is determined by carrying out the following test.
Within the measuring range of skin electrical resistance specified by manufacturers, choose five measuring values including boundary values for detection. For a device with multiple measuring ranges, each measuring range is tested separately. Choose five measuring values including boundary value for detection specified by manufacturers within each measuring range.