Report from Dialysis Data Computerization Subcommittee Working Group
Scientific Committee, Japanese Society for Dialysis Therapy
Takashi Akiba, Tokyo Women's Medical College
Dialysis Data Computerization Subcommittee Working Group
Discussion at the Dialysis Data Computerization Workshop of the 42nd Annual Conference of the Japanese Society for Dialysis Therapy (JSDT) revealed that data formats which varied with dialysis monitors and manufacturers prevented intensive monitoring with a single host computer, and that software and hardware should be developed and manufactured for each monitor to exchange data between satellites or remote monitors for home hemodialysis. Especially in home hemodialysis, a common format for remote monitor is essential to ensure safety. The Dialysis Data Computerization Subcommittee Working Group of the Scientific Committee in the JSDT prepared a draft protocol for communication between dialysis devices and a host computer on the basis of consultation with the Dialysis Data Control System Working Group of the Japan Industry Society for Artificial Organs, supported by the Comprehensive Research Project of Long-term Chronic Diseases 1997, Health Science Research, Ministry of Health and Welfare.
The design of the draft protocol is based on the performance of the computers of current dialysis monitors. Namely, it is applicable to current devices. Since the JSDT web site is still under construction, the General Affairs and Scientific Committees has agreed to publication of the draft protocol below. The Dialysis Data Computerization Subcommittee will enhance the flexibility, reliability, and data capacity of the protocol by, for example, using error correction and encryption technologies as the computer performance of dialysis monitors increases. Please review the protocol and send comments to JSDT by snail mail or by e-mail to firstname.lastname@example.org.
I wish to express my appreciation to Dr. Kiyohide Fushimi of Tokyo Medical and Dental University for his technical advice and assistance.
Draft Protocol for Exchanging Dialysis Data
I. Target device
This protocol applies only to dialysis machines. All manufacturers of dialysis machines should plan to use the protocol. Host computers are not intended as target devices for this protocol.
2. Transmission requirements
(1) Retry is not considered for dialysis devices that receive a request to send from the host computer.
(2) Request to send (from the host computer to dialysis devices)
The following 3-byte data are used.
1 2 3
K* CR LF
*K = a code for the Japan Industry Society for Artificial Organs
(3) The interval between requests to send should be at least 5 seconds.
3. Transmission data format
The format is shown in Table 1. Detailed information on the format is presented in Table 2.
Table 1 Data format
STX LEN ID DATA SUM ETX
Table 2 Explanation of data format
Name Byte Explanation
STX 2 Data start signal (ASCII code)
K = a code for the Japan Industry Society for Artificial Organs
n = version number (in ascending numerical order from 1)
LEN 3 Data length (ASCII code)
All bytes for ID and DATA are summed.
ID 1 Data identification code (ASCII code)
DATA n Data (ASCII code)
Upper bytes should be set to zero.
SUM 2 Data for sum check.
All bytes for data except for CR/LF are summed, and the two lowest HEX digits are converted to ASCII code.
ETX 2 Data ending signal: CR/LF (ASCII code)
4. Transmitted data
(1) Transmitted data are listed in Table 3.
(2) Not all items in Table 3 are applicable to all dialysis devices.
(3) Dialysate pressure (Item No. 9) may be the same as transmembrane pressure (TMP, Item No. 10). In this case, select either one.
(4) Dialysate concentration (Item No. 7) is for personal dialysis devices.
(5) Data for Items No. 1 through 12 should be based on the 5-byte ASCII representation with a decimal point.
(6) For alarm items, 1 indicates that alarms were raised, whereas 0 indicates no alarms.
(7) Item No. 19 "Other alarms" means alarms other than alarms in Items No. 12 through 18.
Table 3 Transmitted data
No. Item ID code Data Bytes Units
1 Target amount of water to be removed A Hex 5 bytes L
2 Total amount of water removed B Hex 5 bytes L
3 Water removal rate C Hex 5 bytes L/hr
4 Blood flow rate D Hex 5 bytes mL/min
5 Syringe flow rate E Hex 5 bytes mL/hr
6 Dialysate temperature F Hex 5 bytes ??C
7 Dialysate concentration G Hex 5 bytes mS/cm
8 Venous pressure H Hex 5 bytes mmHg
9 Dialysate pressure I Hex 5 bytes mmHg
10 Transmembrane pressure (TMP) J Hex 5 bytes mmHg
11 Duration K Hex 5 bytes min
12 Dialysate temperature alarm a Hex 1 byte
13 Concentration alarm b Hex 1 byte
14 Venous vein alarm c Hex 1 byte
15 Dialysate pressure alarm d Hex 1 byte
16 TMP alarm e Hex 1 byte
17 Air detection alarm f Hex 1 byte
18 Blood leakage alarm g Hex 1 byte
19 Other alarms x Hex 1 byte
Table 4 Members of the Dialysis Data Computerization Subcommittee
Takashi Akiba (Chairman), Tokyo Women's Medical College
Masanori Akiyama, International Medical Center of Japan
Shinichi Ueno, Tsuchiura Kyodo Hospital
Tadayuki Kawasaki, Maeda Memorial Renal Institute
Hisamitsu Sato, Masuko Memorial Hospital
Takashi Shibamoto, Tokyo Medical and Dental University
Soshu Shin, Motomachi HD Clinic
Shingo Takezawa, Suzuka University of Medical Science and Technology
Kaoru Tabei, Jichi Medical School
Shuichi Nasuno, Yokohama Rosai Hospital
Honami Fujii, Tokai University Hospital