Medical Markup Language (MML) version 2.21 is characterized by XML as meta language, module structure for each document and enhancement of linking function among documents. Data exchange specification was also added for query and reply. MML instance is composed of MML header and MML body. MML header includes the information for data transmission, while MML body includes several module items. One module item contains only one module and one document information. Nine MML modules are defined at the present time; patient information, health insurance information, diagnosis information, lifestyle information, basic clinic information, particular information at the time of first visit, progress course information, surgery record information and clinical summary information. MML2.21 specification was published in November 1999 and the implementation has progressed in several hospitals and software vendors.

 In exchanging clinical data between healthcare providers, granularity of exchanged data and application coverage of exchanging standard are not satisfied in the same time. Seeking high level data exchange, where exchanged datum goes into recipient database and is able to be used as retrieval key, usecase must be clarified. The authors first stated MERIT-9 patient data referral standard, which is based on XML-DTD with HL7, DICOM entities, then prepared a MERIT-9 editor on HIS clients of PC-ORDERING97. Two MERIT-9 referral document browsers were developed, one at Tokyo University Hospital, another at Hamamatsu University Hospital. The MERIT-9 referral document exchange between the HIS client editor and two browsers were successful. The authors plan to extend this feature to other HIS clients, as well as clinic office PC's. This MERIT-9 referral document standard will be kept coherent with the Ministry of Health and Welfare project, which is expected to output basic data element set for clinical data exchange between healthcare providers.

 Progress of medical technology and information technology promotes telemedicine by networking between regional hospitals in distance areas. As the Yamaguchi Health & Welfare Networking (YH&Wnet) constructed by wide area virtual private network will be one of the important contents of information super highway developed in Yamaguchi prefecture, we have launched grouping and networking of hospitals and clinics in the spheres for health care services.

 This paper shows the structure and function of YH&Wnet and makes the problems clear to construct it as a wide area secure network.

 We built hospital ATM network in 1999. This network is infrastructure of telemedicine system, and two steps of fire wall and VPN (Virtual Private Network) are features. This time, we developed the telemedicine system how this network was applied. Primarily we considered that operation of this system was easy. Knowledge of network is unnecessary to users. Only they set a photograph at a scanner and select a sending point, and inputs password, they can share the medical information which is security through Internet. They can utilize this system as Internet terminal usually furthermore. We think that it is practical telemedicine system.

 Security enhancement for access to patient information in the Tokyo Medical University network system was introduced to consolidate a secure remote medical research and information access system.

 Fingerprint authentication and encipherment devices were installed in high-speed digital (HSD) circuit connecting the four facilities.

 Data encipherment by virtual private network (VPN) technology based on a point-to-point tunneling protocol (PPTP) was also performed by specially developed in software.

 Introduction of a onetime password system using an IC card is being considered candidate for future development plans.

 Since 1999, a telemedicine system, connecting Toyama Medical and Pharmaceutical University Hospital with the district hospitals, has been developed using ISDN at 1500kbps. This system facilitates the clinical consultation from the relatively small clinics. As it was speculated that clinical information systems and descriptions of patients’ profiles, vary among facilities, the Medical Markup Language(MML) was introduced. The patients’ information, coded in MML, is sent with JPEG image files by e-mail. In the university hospital, the MML files are stored on the database server with its own unique file name. This system results in good database construction and search performance. However, there are difficulties in standardizing digitized films, and in setting up the router that separates the dial-up connection to the University hospital from the internet connection via commercial provider.

 We discussed some proble ms to distribute PACS to wide area such as inter-department or inter-hospital. We developed a networked image display system based on WWW technologies. The system utilizes a couple of method; image processing and image compression running on a Web server and user interface based on JavaScript running on a Web browser. Imaging workstation like look-and-feel and performance on a Web browser is achieved.

 High-quality healthcare information services among healthcare institutes distributed across a wide area network have usually been provided using one of two methods. The more common method is to exchange the contents of healthcare information in a predefined format, usually text. Message transfers by HL7 and EDIFACT are examples of this. However, this method has disadvantagesdue to the loss of information caused by serializing real objects in a healthcare information system. The other method, less common, is to access healthcare information directly from a remote site. In this approach information is accessed using the same healthcare software application programs as are used internally in a healthcare institute, but from another healthcare institute across a wide area network. In this paper, we propose a new secure framework based on public key infrastructure for providing dynamic healthcare information services through a wide area network. It providessecurity of service, scalability of connected networks and seamless connection between intranets and the Internet. Although the framework refers to Kerberos, it is actually completely different in that it is based on public key infrastructure. In addition a proxy server is introduced to the framework as a countermeasure to denial-of-service attacks. We conducted preliminary experiments demonstrating that the framework possesses the same level of processing efficiency as Kerberos and about three times more robustness against denial-of-service attacks.

 It is important to use medical information system in order to offer nursing care service continuously. However, it is one of the most critical systems concerning security issues such as privacy protection and data integrity, too.

 The purpose of this study is to avoid leaking out the privacy and to keep security of network system. In th is paper, we especially propose to transmit data by using a steganography that is one of digital envelope technologies, what we call. We made this function up the nursing guidance system of decubitus care that we are now constructing. By means of covering nursing information data up with diseased image data, patients' privacy is protected. Further, by means of binding image data and text data, we are able to transfer the data easily.

 The system based on steganography will be a useful tool because we can send them as attachment files with electric mail.

 The Japan Association of Obstetricians and Gynecologists (JAOG) authorized the medical standard format for the recording of perinatal information in 1996 to introduce the optical card “as the mother card” and realize the medical information network which is regarded as the most important project to improve the perinatal medicine in 21 century. (http://www.jaog.or.jp/JAPANESE/MEMBERS/JOUHOU/H10/index.htm). In Kagawa Prefecture, a perinatal medical information network “Kagawa health and welfare information network” was developed and introduced on October 1998. (http://www.hw.kagawa-swc.or.jp/net/) In this network, four hospitals including Kagawa Medical University and other three public hospitals are connected with each other and function virtually as one perinatal medical center. In this system, all medical information are stored and transmitted based on the standard format of JAOG. There are still many problems, research into the use of medical information should be continued.

 Since internet technologies have become extremely popular and the care insurance have introduced, we will need to exchange the various information among facilities. Recently, the pharmaceutical information also are disclosure to public on many web sites. The purpose of this paper is to transmit the information which is suitable for each user sites and to exchange more trustful information among facilities using a form of XML. Although in the pharma-ceutical information only drug information have made a database in facilities, these are not connected closely.

 In this research, we design a system that the pharmaceutical information user required are selected, transmitted and combined with information on other web sites. In the first stage, the system selects and the information based on the keyword the user designate from the web sites, FDA, MCA and MHW. In the second stage, the system formalized suitable XML format. In the last stage, it give an appropriate output form through the stylesheet that was designed previously. Because we adopt a XML format, the users are able to easily exchange the information among medical facilities and to cooperate with business application systems.

 It is necessary for more effective healthcare delivery to exchange patient medical records smoothly between related medical institutions. In order to establish such smooth exchange of large volume medical data, we have to develop a networking system with large capacity among medical institutions. The wireless LAN of which technology has been extensively improved in recent was investigated whether it is appropriate as a tool to develop that networking system. It was revealed that the wireless LAN can satisfy the conditions to develop a networking system for regional healthcare co-operation. In comparison with other tools, the wireless LAN is very chip and available at present. Although the super high way network will be available within several years to ten years, it was emphasized that to develop a networking system for regional healthcare by using wireless LAN is very meaningful.

 Computer communication has been greatly expanded thanks to the Internet, enabling doctors at hospitals to exchange medical information to each other by e-mail. And Medical institutes of various fields can share their information by using the IC-cards with Electronic Medical Records in them. As the guide, we classify medical information systems into three types. In this paper, we point out the possible danger of relying too much on the tamper resistance alone in terms of security. Furthermore, we examine the necessity of security system using the cryptography technology via the network and examine the condition of security against various attacks.

 Although the differences in colors reproduced by various displays may cause erroneous medical diagnoses, it will take still a more time to establish a comprehensive theory to standardize the color in medical imaging. Then the Morphological Internet Survey Research Project Team (1998-1999) proposes a temporary solution, in which a set of typical medical images with their diagnoses authorized in advance is used as a practical calibrator for common display equipment.

 With the growing numbers of patients who are transferred from hospital to the community, the need for some guidelines related to sharing the patient’s information across institutions has become apparent. A questionnaire survey was given to hospital nurses regarding the necessity of information sharing and ethical problems involv ed. Whereas most of the nurses supported information sharing across institutions, they exhibited two major ethical concerns: privacy and confidentiality. Discussion on these two concepts based upon the ethical decision making process proposed by the authors lead to the following conclusion: 1) Information sharing should not be discouraged due to over concern about patient’s privacy. 2) In continuity of care, confidentiality among health professional is maintained, 3) Home care nurses should more utilize patient’s information from hospital.

 Cooperation between medical facilities in use of computer networks is expected to become popular in the future, because efficient usage of medical resources is important. For electrical exchange of medical information between hospitals, it is necessary to standardize the items and structure of such information. In Japan, however, standardization of exchange of medical information is still insufficient. Few hospitals actually exchange their medical information with other hospitals.

 In this paper, we describe a reporting system for endoscopic examination using XML (Extensible Markup Language) data-description language. This system, which is under construction, is designed for exchange of information on results of endoscopic examination between departments and between hospitals. Because both standardization of endoscopic terms and clarification of the structure of information are attempted in this system, information can be mutually utilized by differentsystems and re-used for making medical decisions and statistical analysis.