ISO 20498-1:2019
(Main)Traditional Chinese medicine — Computerized tongue image analysis system — Part 1: General requirements
Traditional Chinese medicine — Computerized tongue image analysis system — Part 1: General requirements
This document specifies general requirements for a computerized tongue image analysis system (CTIS). This document is limited to the safety aspects and technical requirements for a CTIS, excluding the diagnosis or interpretation of tongue images.
Médecine traditionnelle chinoise — Système d’analyse d’images numérisées de la langue — Partie 1: Exigences générales
General Information
Buy Standard
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 20498-1
First edition
2019-03
Corrected version
2019-05
Traditional Chinese medicine —
Computerized tongue image analysis
system —
Part 1:
General requirements
Médecine traditionnelle chinoise — Système d’analyse d’images
numérisées de la langue —
Partie 1: Exigences générales
Reference number
©
ISO 2019
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Components of CTIS . 2
5 Technical requirements . 2
5.1 General . 2
5.2 Tongue positioning . 2
5.3 Lighting part . 2
5.4 Image acquisition part . 3
5.4.1 General. 3
5.4.2 Spatial resolution . 3
5.4.3 Colour components . 3
5.4.4 Colour components acquirement . 4
5.5 Data processing part . 4
5.6 Display . 4
6 Safety . 4
6.1 Safety of material . 4
6.2 Prevention from infection . 4
6.3 General requirements for testing of ME equipment . 4
6.4 Electrical hazards . 5
6.5 Mechanical hazards . 5
Annex A (informative) Tongue positioning . 6
Annex B (informative) Test methods for CTIS . 7
Annex C (informative) Data processing part . 9
Bibliography .11
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 249, Traditional Chinese medicine.
A list of all parts in the ISO 20498 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
This corrected version of ISO 20498-1:2019 incorporates the following corrections:
— edition date in the running header changed to 2019;
— copyright date in the footer changed to 2019.
iv © ISO 2019 – All rights reserved
Introduction
The tongue’s colour, form, motion, substance and coating are the main factors to be considered when
analysing tongue features. Measuring the geometric shape involves observing the changes in the
thickness and size of a tongue and the cracks and teeth marks on its surface. The important features of
the tongue coating which cover the surface of the tongue are colour, degree of wetness, thickness, form
and distribution.
Although tongue diagnosis is convenient and non-invasive, it is difficult to achieve an objective and
standardized examination. Differences in inspection circumstances, such as light source or a client’s
posture, affect the result significantly. Moreover, as the diagnosis relies on the observer’s experience
and knowledge, it is hard to obtain a standardized result. Recently, many research projects have
attempted to solve these problems, and various types of computerized tongue image analysis system
(CTIS) have been developed.
Various cameras, such as a commercial digital camera, bayer charge-coupled device (CCD) camera,
high-performance 3CCD camera and a hyperspectral camera, were used for the CTIS. Recently, a multi-
view CTIS has been developed designed for 3D tongue modelling and sublingual vein acquirement,
comprising 3D CTIS.
Different CTIS technologies have unique advantages and specificities according to the application
and diagnostic environment, but this variation may cause inconsistent diagnoses in practical clinical
application. To improve CTIS performance and clinical approach, it has become necessary to develop an
International Standard for the functions and elements of a CTIS.
INTERNATIONAL STANDARD ISO 20498-1:2019(E)
Traditional Chinese medicine — Computerized tongue
image analysis system —
Part 1:
General requirements
1 Scope
This document specifies general requirements for a computerized tongue image analysis system (CTIS).
This document is limited to the safety aspects and technical requirements for a CTIS, excluding the
diagnosis or interpretation of tongue images.
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 for 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
ISO 20498-2, Traditional Chinese medicine — Computerized tongue image analysis system — Part 2: Light
environment
IEC 60601-1:2005/AMD1: 2012, Medical electrical equipment — Part 1: General requirements for basic
safety and essential performance
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 https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
computerized tongue image analysis system
CTIS
device or system used to acquire tongue images to be analysed by computer
3.2
charge-coupled device
CCD
device for the movement of electrical charge, usually from within the device to an area where the
charge can be manipulated
3.3
tongue positioning
guiding and maintaining the posture of the protruding tongue
3.4
lighting part
structure for illuminating the tongue surface with various light sources and optical techniques
3.5
image acquisition part
image sensor and optical lenses used to produce the tongue image data
3.6
data processing part
computer and image correction algorithms for computing and displaying the tongue properties
4 Components of CTIS
The CTIS consists of a lighting part, an image acquisition part, a data processing part, a display and, if
provided, a tongue positioning part.
5 Technical requirements
5.1 General
The technical requirements for the components of a CTIS are specified in this document to improve the
accuracy and reproducibility of the acquisition, correction, and feature extraction of the tongue image.
5.2 Tongue positioning
CTIS shall be applied to the tongue positioning to obtain an undistorted tongue image. Tongue
positioning is not necessary for CTIS with non-tongue positioning and mobile CTIS.
Differences in the location and incident angle of the image acquisition part can diminish the
reproducibility of the information in tongue images. The whole area of the exposed tongue shall be
included in the image for analysis. See Annex A for additional information.
5.3 Lighting part
For the colour image acquisition, the luminance, colour temperature, colour rendering index and
illumination distribution shall be considered. The light shall illuminate five areas of the tongue (see
Figure 1). The detailed requirements for the lighting part described in ISO 20498-2 shall be used. See
Clause 6 for information on electrical safety and the biocompatibility of the lighting part.
2 © ISO 2019 – All rights reserved
Key
1 root of the tongue
2 right margins of the tongue
3 left margins of the tongue
4 centre of the tongue
5 tip of the tongue
Figure 1 — Five areas of the tongue
5.4 Image acquisition part
...
INTERNATIONAL ISO
STANDARD 20498-1
First edition
2019-03
Corrected version
2019-05
Traditional Chinese medicine —
Computerized tongue image analysis
system —
Part 1:
General requirements
Médecine traditionnelle chinoise — Système d’analyse d’images
numérisées de la langue —
Partie 1: Exigences générales
Reference number
©
ISO 2019
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Components of CTIS . 2
5 Technical requirements . 2
5.1 General . 2
5.2 Tongue positioning . 2
5.3 Lighting part . 2
5.4 Image acquisition part . 3
5.4.1 General. 3
5.4.2 Spatial resolution . 3
5.4.3 Colour components . 3
5.4.4 Colour components acquirement . 4
5.5 Data processing part . 4
5.6 Display . 4
6 Safety . 4
6.1 Safety of material . 4
6.2 Prevention from infection . 4
6.3 General requirements for testing of ME equipment . 4
6.4 Electrical hazards . 5
6.5 Mechanical hazards . 5
Annex A (informative) Tongue positioning . 6
Annex B (informative) Test methods for CTIS . 7
Annex C (informative) Data processing part . 9
Bibliography .11
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 249, Traditional Chinese medicine.
A list of all parts in the ISO 20498 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
This corrected version of ISO 20498-1:2019 incorporates the following corrections:
— edition date in the running header changed to 2019;
— copyright date in the footer changed to 2019.
iv © ISO 2019 – All rights reserved
Introduction
The tongue’s colour, form, motion, substance and coating are the main factors to be considered when
analysing tongue features. Measuring the geometric shape involves observing the changes in the
thickness and size of a tongue and the cracks and teeth marks on its surface. The important features of
the tongue coating which cover the surface of the tongue are colour, degree of wetness, thickness, form
and distribution.
Although tongue diagnosis is convenient and non-invasive, it is difficult to achieve an objective and
standardized examination. Differences in inspection circumstances, such as light source or a client’s
posture, affect the result significantly. Moreover, as the diagnosis relies on the observer’s experience
and knowledge, it is hard to obtain a standardized result. Recently, many research projects have
attempted to solve these problems, and various types of computerized tongue image analysis system
(CTIS) have been developed.
Various cameras, such as a commercial digital camera, bayer charge-coupled device (CCD) camera,
high-performance 3CCD camera and a hyperspectral camera, were used for the CTIS. Recently, a multi-
view CTIS has been developed designed for 3D tongue modelling and sublingual vein acquirement,
comprising 3D CTIS.
Different CTIS technologies have unique advantages and specificities according to the application
and diagnostic environment, but this variation may cause inconsistent diagnoses in practical clinical
application. To improve CTIS performance and clinical approach, it has become necessary to develop an
International Standard for the functions and elements of a CTIS.
INTERNATIONAL STANDARD ISO 20498-1:2019(E)
Traditional Chinese medicine — Computerized tongue
image analysis system —
Part 1:
General requirements
1 Scope
This document specifies general requirements for a computerized tongue image analysis system (CTIS).
This document is limited to the safety aspects and technical requirements for a CTIS, excluding the
diagnosis or interpretation of tongue images.
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 for 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
ISO 20498-2, Traditional Chinese medicine — Computerized tongue image analysis system — Part 2: Light
environment
IEC 60601-1:2005/AMD1: 2012, Medical electrical equipment — Part 1: General requirements for basic
safety and essential performance
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 https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
computerized tongue image analysis system
CTIS
device or system used to acquire tongue images to be analysed by computer
3.2
charge-coupled device
CCD
device for the movement of electrical charge, usually from within the device to an area where the
charge can be manipulated
3.3
tongue positioning
guiding and maintaining the posture of the protruding tongue
3.4
lighting part
structure for illuminating the tongue surface with various light sources and optical techniques
3.5
image acquisition part
image sensor and optical lenses used to produce the tongue image data
3.6
data processing part
computer and image correction algorithms for computing and displaying the tongue properties
4 Components of CTIS
The CTIS consists of a lighting part, an image acquisition part, a data processing part, a display and, if
provided, a tongue positioning part.
5 Technical requirements
5.1 General
The technical requirements for the components of a CTIS are specified in this document to improve the
accuracy and reproducibility of the acquisition, correction, and feature extraction of the tongue image.
5.2 Tongue positioning
CTIS shall be applied to the tongue positioning to obtain an undistorted tongue image. Tongue
positioning is not necessary for CTIS with non-tongue positioning and mobile CTIS.
Differences in the location and incident angle of the image acquisition part can diminish the
reproducibility of the information in tongue images. The whole area of the exposed tongue shall be
included in the image for analysis. See Annex A for additional information.
5.3 Lighting part
For the colour image acquisition, the luminance, colour temperature, colour rendering index and
illumination distribution shall be considered. The light shall illuminate five areas of the tongue (see
Figure 1). The detailed requirements for the lighting part described in ISO 20498-2 shall be used. See
Clause 6 for information on electrical safety and the biocompatibility of the lighting part.
2 © ISO 2019 – All rights reserved
Key
1 root of the tongue
2 right margins of the tongue
3 left margins of the tongue
4 centre of the tongue
5 tip of the tongue
Figure 1 — Five areas of the tongue
5.4 Image acquisition part
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.