- International Journal of Medical Informatics
Contents
1. T S0000 eS T 0O0000000 DODO z000009003 2909P m OCO000O 1205555920PP2HOHO had NOODOOOOOPOODD I sORAB2C Velelbishelete SODODOOOOS 00008 DO rai eer o000 O000GS 85 gt amm 3 RI op R EAEE ERREEN ats A Fig 8 A photograph of a developed acquisition module 4 Examination and conclusion It is not easy to individually monitor many incuba tors installed in an infant ICU The web based re mote supervisory control system developed in our study makes it possible to monitor conditions of incubators from any place within the hospital and to also identify minute changes by monitoring the system s trend function Our experiment equipped each of four incubators with a measuring module and connected the mod ules to a web server via a wire interface to a RS485 connector Using our system supervisory staff could identify an incubator with unusual conditions and respond immediately to alarms emitted by the sys tem Our system could be further improved by using a wireless interface eliminate the need for a wire connection Fig 9 In conclusion this study presents a solution to the need for centralized supervisory control and management especially as use of various types of equipment used in hospitals increases in the future 156 D I Shin et al Web based Monitoring of Infant Incubators NICU Status AMC Degree 45 40 35 J0 25 Temperature Incubator 001 Fig 9 A sample snapshot of web ba2. E DE RERO Fig 3 Multiple interfaces of the RS485 154 7 A Sensor EF pnnosese Module Network Network Infant Intranet Intranet Incubator 1 gt Sensor Module Infant Incubator n Monitoring Station Fig 5 A block diagram of whole system power source for the measuring modules was 9 V supplied by a separate switching power supply for each module The 9V was then converted to 5V by a regulator in each measuring module 2 2 System operation 2 2 1 Web server operation Two process are needed to operate the web server The first involves controlling the web server board including network registration of and identification of web resources The second involves making the web resource respond to the client s demand The web sever is controlled by standard utility soft ware supplied by the manufacturer The software enables utility software to enter a designated hard ware address on the PC and register the authorized IP address for firmware in the web server with the hospital s network This allows the compound web server to be recognized as a single server on the hospital s network and allows upload of web based resources operating on the web server to devices on the PC network The web resource performs its assigned task which is to gather tem perature and humidity data from the measuring modules installed in the incubators connected to the RS485 interface and to then transmit the in formation
3. mode transmits temperature and humidity data stored in the measuring module each hour at one time and aims to show the trend over 12 or 24h Bit 3 Bit 2 Bit 1 Bit 0 Remote monitoring of infant incubators in the ICU T request for temperature date transmission requesting current temperature data to the mea suring module at 1 e H request for humidity date transmission re questing current humidity data to the measuring module at 1 e C request for serial data transmission request ing serial data to the measuring module at 1 e B request for emission of alarm signal request ing emission of alarm signal to the measuring module e D3_9 length of serial data n requesting tem perature and humidity data for the latest 2 h 2 2 3 Storing and display of measured data To transmit data serially the measuring module stores temperature and humidity data into FIFO memory 32KB which is capable of storing tem perature and humidity data for 24h into 8 bits at 15s intervals With the exception of the 24h stor age described in the above case every time the web server requests a data transmission the latest temperature and humidity data can be transmitted to it Moreover the data from all measuring modules is set to renew once every 10s and is represented in the form of numbers which can be sent as a single transmission The data from each measur ing module within the scope of 12 or 24h time frame can be set to s
4. the precision of the amplifier and error introduced by the A D converter 9 Therefore this system has a measurement range limit such that the degree of accuracy in indicating temperature is 0 1 C and the measuring range of incubator temperature is narrow approximately 30 40 C To solve this problem of inaccuracy a correction algorithm for the final obtained temperature data was used to keep the precision of measured temperature in the incubator at a fixed temperature within an indicat ing precision of 0 1 C The case of humidity was handled in the same way These correction algo rithms are performed in a 8 bit micro controller PIC16C73 10 As the overall block diagram represents a mea suring module is installed at each location that needs monitoring This suggests that if the man aging staff wants to conduct web based remote supervisory control of the all 32 incubators in the infant room they should connect one web server on the web with 32 measuring modules In accord ing to this method an RS485 mode was applied to the measuring modules and the web server board MAX485 was selected for operating the RS485 in terface which sends and receives using only one transmission channel in a half duplex mode The interface consists of an 8 pin package so that it is possible to connect up to 128 lines at most while also allowing miniaturization of the modules Fig 1 shows a block diagram of each module Fig 2 shows the inter
5. to a client in response to the client s request The web resource is implemented by adding a Java applet to an HTML base Once the client ac cesses the web server the Java applet is down loaded to the client then the web server requests data transmission from the measuring module con nected to the RS485 interface This request is ini Table 1 Bit definition of prompts byte Bit 7 Bit 6 Bit 5 Bit 4 D3 D2 D1 DO D I Shin et al Web Server to Module Module to Web Server Fig 6 Signal protocol between the web server and a measurement module tiated by demand of the applet Finally tempera ture and humidity data from the measuring module is returned to the client The Java applet downloaded to the client can display the overall temperature and humidity con ditions from each measuring module or can repre sent the conditions reported by a measuring module each hour as a graphic diagram 2 2 2 Signaling protocol Fig 6 shows the protocol mode that the web server uses to request data transmission from a spe cific measuring module upon a client s request to transmit the ID of the measuring module and com mand language The structure and operation of the command language was defined as represented in Table 1 The transmission mode from the measuring mod ule to the web server was divided into a single transmission mode and a serial transmission mode for use depending on the type of command re ceived The serial
6. 85 port on the web server board and creates a web document containing these data The system manager can maintain centralized supervisory monitoring of the situations in all incubators while sitting within the infant ICU at a work space equipped with a personal computer The system can be set to monitor unusual circumstances and to emit an alarm signal expressed as a sound or a light on a measuring module connected to the related incubator If the system is configured with a large number of incubators connected to a centralized supervisory monitoring station it will improve convenience and assure meaningful improvement in response to incidents that require intervention 2003 Elsevier Ireland Ltd All rights reserved Infant incubator Intensive Care Unit ICU Monitoring 1 Introduction Central monitoring systems used in Intensive Care Units ICUs are convenient and essential They enable managing staff to monitor patients circum stances using real time operating system through out the ICU However there is no such central monitoring system in the infant ICU Staff must walk around and check incubators one by one Corresponding author Tel 82 2 3010 5101 fax 82 2 3010 5290 E mail address sjhuh amc seoul kr S J Huh Fortunately remote supervisory control technol ogy and devices to connect equipment in need of control with the web have created the possi bility of studies of web based monitoring system which ha
7. International Journal of Medical Informatics 2003 71 151 156 International Journal of Medical Informatics www elsevier com locate ijmedinf SHORT COMMUNICATION Web based remote monitoring of infant incubators in the ICU D I Shin S J Huh T S Lee 1 Y Kim Department of Biomedical Engineering Asan Medical Center and University of Ulsan College of medicine 388 1 PungNap Dong SongPa Gu Seoul 138 736 South Korea Department of Biomedical Engineering College of Medicine Chungbuk National University ChungJu South Korea Department of Biomedical Engineering College of Medicine Hanyang University Seoul South Korea Received 26 March 2003 received in revised form 13 June 2003 accepted 13 June 2003 KEYWORDS Summary A web based real time operating management and monitoring system Web based for checking temperature and humidity within infant incubators using the Intranet Intranet has been developed and installed in the infant Intensive Care Unit ICU We have created a pilot system which has a temperature and humidity sensor and a measuring module in each incubator which is connected to a web server board via an RS485 port The system transmits signals using standard web based TCP IP so that users can access the system from any Internet connected personal computer in the hospital Using this method the system gathers temperature and humidity data transmitted from the measuring modules via the RS4
8. efore most incubators have their own temperature and humidity sensor built in and have a function of signal interfacing to a PC or other devices on the outside of the incubator 7 Development of our monitoring system called for creating a new measuring module for checking temperature and humidity as different standard interfaces and signaling protocols are used by the various existing modules To achieve this aim we used a platinum resistance temperature detec tor as the temperature sensor because it is small and easy to install in an incubator and it mea sures straight line resistance temperature over a relatively wide temperature range especially within the 30 40 C range needed to monitor the temperature of an incubator 8 In practice the measuring network provides constant current to the platinum resistance temperature detector and measures its electric potential difference which is converted to a digital value between 0 and 255 by a micro controller in the measuring module and is then calculated as the actual temperature by a correction algorithm This measuring module Stores the actual temperature and humidity value or transmits its data on demand of the web server after processing of the correction algorithm and after converting the analog signal from the tem perature and humidity sensors to a digital signal The degree of accuracy may be influenced by var D I Shin et al ious factors including deviation of the sensor
9. end by serial transmission or to send at one time It is represented as a graphic dis play for clients needing to monitor 12 or 24h trend data 3 Results of experiment As a result of our experiment it can be said that management staff can use the web to monitor and manage temperature and humidity within infant incubators Fig 7 shows a web server board con nected via RS485 and Fig 8 shows a measuring module for checking temperature and humidity In our experiment we manufactured and connected four measuring modules with the web server board via the RS485 interface The control center in the infant ICU can perform primary supervisory control of incubators as cir cumstances demand Any place connected to the web network system within the hospital can exer cise control Supervisory control of incubators can not rely only on this system however a central monitoring system conveniently identifies problems needing solution and prompts staff to respond im mediately to those problems 155 vert SUPPLY RJ45 CONNECTOR ot ah D a _ RS ZALIG PORT 4 7 bi gt Bribe stest Rit ae i l g i a pel Eine be iad Me iii la st i i 3 o e mE ii t 00000090 00aN0 7000000000000 0000000000090 SENSOR INPUT OUTPUT INPUT RS 485 POWER a O of Pts 3 ie 100S ooh Roger A 5 c gt s BS A ire a OOO oon SOOD 5000004 o 4 85222BpeRRRR OMA RRBRO AE Dai 4i
10. face between the module and the web server Fig 3 shows a connection diagram of the RS485 multi interface in the applied half duplex mode The half duplex mode has both merit and demerit The advantage that a transmission channel can op erate using just two lines This advantage must be weighed against the limitation that only one master on the sending side can operate at any given time The termination resistance 120 2 for impedance matching was set to connect to both the start point and end point of the transmission channel Also 26AWG twisted line with an impedance 12 Q was used to optimize transmission conditions 11 There was no distance limit owing to the techni cal ability to transmit up to 1200m which was sufficient for our needs Again the purpose of this research is the central monitoring of infant incubators with simple attach ment of our sensors So we would not modify the inner circuits of infant incubators as possible 2 1 2 Web server The data from each measuring module is transmit ted to the web server via the RS485 multi interface Remote monitoring of infant incubators in the ICU From Temp Sensor From Humi Sensor Fig 1 Serial Interface Web server o Internet Fig 2 modules Module n Interface between web server and acquisition The web server specifications are as follows e 8 bits 50 MIPS processor SX52BD e 512KB flash memory storing web resource and contr
11. ol variable 10 Base T Ethernet interface with RJ45 jack TCP IP stack and built in web server firmware e RS232 485 interface maximum safe speed of 38 400 baud IP control and change and upload of web re sources on a Windows based running 95 98 NT 2000 PC can be accomplished with a web server having an Ethernet controller RS232 485 serial interface and 512KB flash memory built in and operated by an 8 bit microprocessor as Fig 4 rep D DE REAO A D Conversion Processing F 153 Serial i Interface Web server A block diagram of the acquisition module 10 Base T Ethernet Controller Filter 10 Base T 512KB Flash Memory RJ45 Connector To Ethernet x52BD Microprocessor 1 Serial Port RS232 485 Fig 4 A block diagram of the web server board resents The device plays an independent role providing the basic functions of a web server 2 1 3 Overall system organization The overall system map is shown as Fig 5 The mea suring module for each incubator is connected to a web server board via an RS 485 port A Java program on the web server board requests data transmission from each measuring module cyclically Data trans mitted to the web server board is expressed in the form of anumber or a graphic display on a PC screen connected to the web Our study used a web server board capable of having 64 measuring modules at most which en abled it to connect with only four incubators The
12. on Press 1989 pp 12 155 10 C H Shin Technical Handbook of PIC16C7X Comfile Tech nology Press 1999 11 Maxim Semiconductor a datasheet of MAX485 http www maxim ic com 1999 Available online at www sciencedirect com science oinecrs
13. sed incubator monitoring Acknowledgements This work is the result of research activities of Advanced Biometric Research Center ABRC sup ported by KOSEF References 1 J S Park W K Min K S Lim T H Lim J S Lee W S Kwack H I Cho Development of web based laboratory information accessing system J Korean Soc Med Inform 5 1 1999 149 155 2 J W Choi Y H Kim S K Lee J O Lee B H Oh H I Cho A telemedicine system using B ISDN J Korean Soc Med Inform 3 2 1997 141 146 3 H Takeda Y Matsumura S Kuwata H Nakano N Sakamoto R Yamamoto Architecture for networked elec tronic patient record systems Int J Med Inform 60 2000 161 167 4 A W Kushniruk C Patel V L Patel J J Cimino Televaluation of clinical information systems an integra tive approach to assessing web based systems Int J Med Inform 61 2001 45 70 5 S Y Belal A J Nevill P Jeyaratnam A computerized data acquisition system for infusion devices a clinical support tool or a risk management tool J Med Eng Technol 25 2 2001 61 67 6 F Magrabi N H Lovell B G Celler A web based approach for electrocardiogram monitoring in the home Int J Med Inform 54 1999 145 153 7 Infant Incubator Service Manual Air shields 8 K S Whang Case Study of Sensor Application Kijeon Re search Press 1989 pp 633 686 9 A Dictionary of Electronic Circuits Sew
14. ve evolved over several decades 1 4 Of course some computerized data acquisition meth ods for infusion devices were already attempted 5 On the other hand web server board con trolling devices of every kind have been commer cialized for popular use with web based systems A web server board offers great convenience to users who need to connect and control existing equipment 6 1386 5056 S see front matter 2003 Elsevier Ireland Ltd All rights reserved doi 10 1016 S1386 5056 03 00095 9 152 The aim of study is to help to manage and mon itor conditions within incubators in the infant ICU using the hospital network to overcome space limits that restrict available room for controlling equip ment and to enable immediate response to unusual circumstances Accordingly we developed a module for mea suring temperature and humidity within an infant incubator and installed it in four incubators We connected these to a web server board using an RS485 interface A web document based on the Java programming language was created on the web server board The document gathers temper ature and humidity data and transmits it to the client To assure data security the web document can be accessed only with an authorized ID and password 2 Methodology 2 1 System organization 2 1 1 Measuring module Internal temperature and humidity are the most im portant conditions that need to be monitored in an infant incubator Ther
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