Takashi Suzuki1)3), Kunihiro Chizuwa2), Masazumi Sugahara2), Masaaki Niimura2) and Tadayuki Kawasaki3)
1) Interdisciplinary Graduate School of Science and Technology(Doctoral Program)，Shinshu University
2) Graduate School of Science and Technology，Shinshu University　 
3) Department of Clinical Engineering，Maeda Institute of Renal Research，Japan

Background

 The authors are developing an intelligent VPN and working for securing safety and quality of treatment with remote monitoring dialysis information as an application for dialysis medical treatment at concerned facilities and home
 It is usually needed to make alterations to the existing network address system when introducing VPN and therefore technical knowledge is required. Moreover, exclusive routers are used for some providers, which suggests VPN cannot be introduced.
 VPN-Bridge we have developed has the following three features.
(1) No network instruments are affected.
(2) No changes are required for addressing systems at all.
(3) Connection is established by simple operations without being regulated from distant places by firewalls.
 Figure 1 shows a structure chart of VPN-Bridge. This enables to handle dialysis machines set up in home as if they are those installed in hospitals.
 If dialysis conditions such as pre-dialysis weight can be transmitted to a dialysis machine, setting errors would be reduced and safety would increase. However, home dialysis patients do not have a measure to send their pre-dialysis weight to the dialysis management systems “STEP Touseki” in hospitals.
 This time, we produced experimentally an application to manage dialysis conditions and discussed on usability of the system.

Figure 1. Structure chart of VPN-Bridge

Methods

 The system was realized as a Web application. Apache, MySQL and php were used for web servers and a web browser was used for a client. http and socket were used as communication methods. For operation, the web servers were connected to the web browser and followings were performed.
(1) Input / save / management of dialysis conditions
(2) Pre-Dialysis Weight is transmitted to “STEP Touseki” and fluid removal calculated in “STEP Touseki” is transmitted to a dialysis machine.
(3) Post-Dialysis Weight is transmitted to “STEP Touseki”.
(4) Input / save / management of equipment used for dialysis
For input data, sql file were created and they were sent from a web server to “STEP Touseki”. After that, the data was registered in a database..
 Figure 2 shows behaviors of this system.
(1) First, a patient inputs his/her pre-dialysis weight in the web.
(2) The web server registers the data in MySQL and database of "STEP Touseki".
(3) "STEP Touseki" calculates fluid removal from the pre-dialysis weight and dry weight registered beforehand.
Moreover, it calculates a ultrafiltration rate from the dialysis time registered beforehand.
(4) "STEP Touseki" sends calculation results to a dialysis machine.
(5) After that, the dialysis machine continues sending dialysis process information to "STEP Touseki".

Figure 2. Behaviors of this system

Results

 Connection was established by intelligent VPN. One of the reasons for this is that VPN-Bridge we have developed is accessible without being affected by restrictions of firewalls, we presume.
 Input and management of dialysis conditions were successfully performed with the proposed application. Moreover, dialysis conditions such as the body weight were successfully transmitted. This is because the system configuration was simple. In other words, the client is available only in a web browser so it was intuitive and easy interface as a major factor. Moreover, patients who have not had connecting means to "STEP Touseki" have come to be able to access the system only through web browsers in our system and therefore our system is epoch-making.
 With the pre-dialysis weight, the fluid removal is calculated in "STEP Touseki" and is transmitted to the dialysis machine. This process reduces setting errors for the fluid removal and increases the safeness. This system can be used for medical billing, usage history and traceability by inputting medical equipment used for a patient in dialysis. This enables patients to gain an understanding of dialysis history themselves.
 Safe, quick and precise hemodialysis therapy was smoothly performed with this system.

Conclusion

 This system connects hospital and patient's house easily with the developed PN-Bridge. This enables to handle dialysis machines set up in home as if they are those installed in hospitals. The dialysis management system "STEP Touseki" monitors information of systems and blood pressure / pulse of a patient by the above connection method.
Patients register their pre-dialysis weight with a Web application. "STEP Touseki" calculates fluid removal and ultrafiltration rate with the registered data and send their results to dialysis machines. Therefore, incorrect setting for dialysis conditions decreases and safeness of dialysis increases. The proposed system enables to perform dialysis smoothly and contributes to security of safety and quality so it is a useful system.
However, there remain problems that must be solved in the future.
 In this system, patients cannot browse dialysis history freely and it will be a future task to be solved.
This time, we performed experiments for one home dialysis patient but we are going to perform connection tests for plural families.
 Furthermore, in the current data-sending method in the Web application, SQL sentences are written in files. However, we aim at establishing a method by which data are registered directly in the database from the Web application.