ISO 20495:2018

INTERNATIONAL ISO
STANDARD 20495
First edition
2018-04
Traditional Chinese medicine — Skin
electrical resistance measurement
devices
Médecine traditionnelle chinoise — Détecteurs de résistance
électrique aux points d’acuponcture
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Technical requirements . 2
4.1 Measurable range . 2
4.2 Accuracy of measurement . 2
4.3 Detection electrical signal . 3
4.4 Electrode force indication device . 3
4.5 Force sensing switch of exploratory electrode . 3
4.6 Detection voltage . 4
4.7 Detection current . 4
4.8 Effective area of auxiliary electrode . 4
4.9 Electrical safety . 4
4.10 Electromagnetic compatibility . 4
4.11 Biological evaluation . 4
Annex A (informative) Particular guidance and rationale . 6
Bibliography . 9
Foreword
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This document was prepared by Technical Committee ISO/TC 249, Traditional Chinese medicine.
iv © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 20495:2018(E)
Traditional Chinese medicine — Skin electrical resistance
measurement devices
1 Scope
This document specifies performance and test methods for skin electrical resistance measurement
devices.
This document is applicable to skin electrical resistance measurement devices through which an
electrical signal is applied on acupuncture points of the human body or specific points of the body
surface 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.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated 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 risk
management process
IEC 60601-1, Medical electric equipment — Part 1: General requirements for basic safety and essential
performance
IEC 60601-1-2, Medical electric equipment — Part 1-2: General requirements for basic safety and essential
performance — Collateral standard: Electromagnetic compatibility — Requirements and tests
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
skin electrical resistance
direct current (DC) resistance value or alternating current (AC) resistance value between acupuncture
points 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)
3.2
skin electrical resistance measurement device
device that can detect electrical resistance on acupuncture points or specific points of the body surface
under the condition of electrical signals being applied to the human body
3.3
detection electrical signal
voltage signal or current signal on device or for match use applied to patient for electrical resistance
detection
3.4
auxiliary electrode
electrode that is fixed on specific points of the patient (e.g. hand-held or fixed on palm or forehead) for
reference use, which is relatively fixed during detection
3.5
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
3.6
detection voltage
root mean square (RMS) of maximum open-circuit voltage between the auxiliary electrode and the
exploratory electrode in the detection electrical signal
3.7
detection current
RMS of maximum current between the auxiliary electrode and the exploratory electrode in detection of
the electrical signal
3.8
electrode force indication device
device on the exploratory electrode or auxiliary electrode whose function is to control or display the
ap
...