Last update: Nov.3, 1999

Introduction

The Special Interest Group of the Japan Association for Medical Informatics "Electronic Health Record Research Group" [1] has been studying methods for exchanging medical data between different facilities since 1994.

In 1995, the idea that data with attributes could be exchanged was born. It was then put into practice with Standard Generalized Markup Language (SGML). This standard was named the Medical Markup Language (MML). The group members have participated in the Electronic Medical Chart Research Project of the Health and Welfare Ministry established in 1995. They have been involved in this research and development for 3 years. The exchange standard has been improved to a practicable level through this process. To implement information (eg. images) that cannot be expressed in the MML, the method to refer to external files such as DICOM from the MML instance was established [2, 3].

Along with installation of the MML, specific designs were required for various departments. It was not possible to cover all medical departments here. Considering the influence on the entire structure due to potentially frequent new designs/changes, it is not efficient to control the MML with respect to the various versions. Therefore, the MML was integrated into a module with XML Namespace suggested by W3C in March 1999 so that modules may be combined for the application concerned as required. This has resulted in a descriptive method particular to each medical department, and in the separation of a logical development structure (Fig.1). This specification and relevant data are disclosed/controlled at the site of the Electronic Health Record Research Group [4].

Overview

Two major and common rules are required for the exchange of medical information. One is the data description method and the other is the data exchange method. In the beginning of development, the data exchange method was not particularly specified in the MML; only the data format was specified. The developed MML could be sent via a floppy disk, mail or FTP. The problem we encountered at the installation stage is that if there was no specification for the exchange method, it would be difficult to exchange the data automatically. When various data transmission methods are being developed, the data cannot be obtained unless the data is requested in the vendor specified format. Assuming that information is exchanged at numerous hospitals and medical information providers, it is necessary to specify a method for request, response and deletion of data based on the MML. (It is not necessary to use this specification for exchange with a portable medium.)

Considering these features, this specification has been prepared in two parts.

Medical Markup Language Part I Data Format Specification
Medical Markup Language Part II Data Exchange Specification

This specification has used XML Version 1.0 recommended in W3C as a meta data description language for exchange.

The following 4 rules must be observed.
1. Information particular to each medical application must be described in XML Namespace.
2. XHTML must be used as Presentation Data (format including data for display). (W3C is currently reviewing XHTML. When the specification is recommended, the recommended specification is implemented into the MML.)
3. The format for date, time, dateTime, timePeriod must be the specification of ISO 8601 [10].
4. It is recommended that the same Prefix character strings as that used in this specification be used for Prefix of XML Namespace. It should operate according to the specification of XML Namespace when installed in the application.

This annoucement explains the MML assuming that readers have a general knowledge of XML. Refer to reference documents [5, 6, 7] for details of XML.

Fig.1 The basic structure of MML 2.2.1

1999.8.13 Announced to working group

Tag list
DTD(text version)
DTD(HTML version)

1999.8.15 Announced to working group

Tree structure of Tag used in MML
Data Format Specification (HTML document)
Data Exchange Specification(MS Word document)

1999.8.23: Announced to Japan Association for Medical Informatics member

Tag list
DTD(text version)
DTD(HTML version)
Tree structure of Tag used in MML
Data Format Specification (HTML document)
Data Exchange Specification(MS Word document)

1999.9.14 Announced to working group

Published MML 2.2.1 beta specification on WWW

1999.9.22 Announced to Japan Association for Medical Informatics member and published on WWW

MML 2.2.1 final specification (Japanese written document) on WWW

1999.11.01 Announced to Japan Association for Medical Informatics member and published on WWW

MML 2.2.1 final specification (English written document) on WWW

[1] Japan Association for Medical Informatics Electronic Health Record Research Group (Japanese written WWW site): http://www.seagaia.org/ehr/

[2] Hiroyuki Yoshihara, Kazuhiko Ohe, Katsuhiro Ohashi, Ryuichi Yamamoto, Shunji Yamasaki, Yasuyuki Hirose, Kunio Matsui, Teruyoshi Hishiki, Yoshinori Yamashita, Kazushi Minagawa, Hiroshi Koyama: Studies on the standardization of exchange procedures of medical information (Japanese written document), 1997, http://www.miyazaki-med.ac.jp/medinfo/SGmeeting/document/mml9702/techcore.html

[3] Hiroyuki Yoshihara, Kazuhiko Ohe, Katsuhiro Ohashi, Ryuichi Yamamoto, Shunji Yamazaki, Yasuyuki Hirose, Kunio Matsui, Teruyoshi Hishiki, Yoshinori Yamashita, Kazushi Minagawa: Studies on the standardization of exchange procedures of medical information (English written document),1997, http://www.miyazaki-med.ac.jp/medinfo/SGmeeting/document/mml9702/techcore_E.html

[4] MML/DTD library (under construction): http://www.seagaia.org/mml/

[5] Extensible Markup Language (XML) 1.0 W3C Recommendation 10-February-1998, http://www.w3.org/TR/1998/REC-xml-19980210

[6] Namespaces in XML World Wide Web Consortium 14-January-1999, http://www.w3.org/TR/1999/REC-xml-names-19990114/

[7] Date elements and interchange formats - Information interchange - Representation of dates and times, http://www.iso.ch/markete/8601.pdf

[8] Seagaia Meeting home page (Japanese written WWW site): http://www.seagaia.org/

[9] MERIT9 group home page (Japanese written WWW site): http://www.h.u-tokyo.ac.jp/merit9/

[10] Date elements and interchange formats - Information interchange - Representation of dates and times: http://www.iso.ch/markete/8601.pdf

Member in Chief:

Hiroyuki Yoshihara: Miyazaki Medical College Hospital (Email: yoshi@miyazaki-med.ac.jp)

Working group core member:

Katsuhiro Ohashi: Ohashi Obst/Gyne Clinic
Shunji Yamazaki: University Hospital, University of the Ryukyus
Yasuyuki Hirose: University Hospital, University of the Ryukyus
Yoshinori Yamashita: Fukui Medical University Hospital
Ryuichi Yamamoto: Osaka Medical College
Kazushi Minagawa: Digital Globe, Inc.
Norihiro Sakamoto: Kyushu University Hospital
Kenji Araki: Miyazaki Medical College Hospital

Working group member:

Yoshinari Shima: Japan DynaSystems, Inc.
Toshiaki Suzuki: Japan DynaSystems, Inc
Hiroyoshi Okamatsu: Otsuka-shokai Co., LTD.
Akihiro Watanabe: Otsuka-shokai Co., LTD.
Tsuneyuki Hoshino: ASAHI SYSTEM AGENCY Co., Ltd.
Kinya Sakai: CAI System Corporation
Kiwamu Takahashi: Satou Hospital
Akihiro Kannari: Self Corporation, Ltd.
Yoshihiro Katada: Merits Inc.
Tomoyuki Ida: ASAHI SYSTEM AGENCY Co., Ltd.
Masahiro Kyushima: Okinawa Chubu Hospital
Liu Tianquan: Sun Japan Corporation
Takashi Suzuki: Maeda Institute of Renal Research Mobara Clinic
Noriaki Morimoto: Miyoshi Orthodontic Office
Kenichi Yajima: Yajima dental clinic

Technical adviser:

Yoshiyuki Kitahara: Infoteria Inc.

This docment was written by Hiroyuki Yoshihara, MD/PhD