Home

GlucoBox System

1. 14 S 2 3 4 RF2 VCC RF Rig 6 2K VCC RF2 C29 C32 C3 ne 100nF 10nF RIS OR VCC RF VCC El 1 PHYCOMP 431312120043 E 4 1 RF2 RFI a 1 SOR line required ro antenna 3 RIS L 100nF IK 12nH 9eozotoa Inductor ZQZEZRZO 2626962 O 88 598 99 BB a a a 1 r 24 Len 5 RFGND XTALOUT 5 1 a 28 Tu TRE PTATBIAS XTALIN OVU z 2 9 3 3 HI A t I SEP NCC j REVDD cs 7 3 2 S 1ovcc2 CRFCS i RFGND MCR a RET 10 13 lovec3 147 24 ANT 10 lt 24 IOVLA IOVCC4 RF IO 5 5 LS Ti Ra RFGND DATAXIO IOVLS l 1ovacs E RF DATAXIO RIO GND 5 DATACLK 7 g 10 16 IOVCC6 Fay RF DATA CLK gt p E pr x lt 286028 NC 3 IOVL7 IOVCC7 gt RE LD P ERESIA IOVLS 2 2 RF RSSI SEROE MAX3001E US 16 MICRF506 MAX3001E RE LD RFO 1 x FRE RSSI RI2 3K InF ee pe R9 10R E al a vi ol vi 5 g SI g VCC RF ND VCC RF m ai dis c rite GlucoBox RF communication InF InF InF InF E 5 Drawn by Sadasing Kowlessur amp Damien Perritaz EPFL Laboratoire de Production A4 Number Microtechnique LPM Revision 1 a COLE POLYTECHNIQUE Date 14 02 2006 Sheeti of 1 1015 Lausanne F D
2. DI Va 2N A RI CHARGE IN PROGRESS Vi 470R LED R2 R3 10K 10K n GREEN BUTION RED BUITON HEADER sUNA Reset circuit with isolati part VEXT ul 0851016 n 3 1 3 N our Hj i IN2 OUT DC PLUG DBSIOIG USB connection VBUS 2 gt D a 4 2 m 6 e B USB mini B Programming Debugging selection 3PINS JUMPER SMD vee aan 15 6 EMUD 5 PGD a ICD PGD 3 ICD PGC 1 PGC EMUC MMSMD6 n 3PINS JUMPER SMD Connector to mainboard M DATA 16 15 MCLR EMUC ia EMUD 8 GREEN BUTTON 3 R4 RS il ZX 10K 47R o D3 D 9 Diode BASTO T Diode BAS16 5 USH BUT 3 3 1 MMSMDI 6 GlucoBox Daughter board Drawn by Sadasing Kowlessur amp Damien Perritaz EPFL Laboratoire de Production Size A4 Number Revision 4 Miertetimique LPM Date 14 02 2006 Sheet of I F 1015 Lausanne F D RALE DE LAUSANNE File _E Master Project PCB GlucoBox System vJEXTENSION Sch Doc HIlHONVOA Z 4 78 DC extemal DC source max 6V 500mA VDD U DBS101G 1 fini out 31 IN2 our
3. 11 2 5 5 Selected system 11 glucose monitoring system is generally composed of three parts a sensor gives glucose rate a control device manages values given by the sensor and a computer software for post analysis This chapter presents some usual glucose monitors with their specifications With the recommendations of a healthcare professional a list of requirements has been established for such systems Some suggested solutions were studied and a solution has been proposed with the choices and their explanation It is important to know that the study has been made on the basis that only a sensor exists 3 93 GlucoBox System LPM EPFL ctr 9 Y 2 1 STATE OF THE ART There is a huge potential market around medical devices Approximately five billion CHF are invested every year for the development of glucose monitoring systems by a large number of firms It is very difficult to obtain competitive devices Several systems have been proposed but only a few of them are currently used in Switzerland 2 1 1 Accu CuEk P 1 This system sold by Roche Diagnostics is the most used in Switzerland and is commonly known to many diabetics The patient usually manages himself his medication between medical appointments and can react according to his glucose level Patient takes his rate three to six times per day to check his level and ta
4. H M9 er Antenna Through this essential component the transceiver will emit and receive RF sig nals Main characteristics are impedance and gain Antenna can be found in various forms each with its advantages and drawbacks Making antennas is itself a field of study In our application antenna performance is not critical a range of only a few meters are required However antenna dimension is the main factor to chose the right one In this context a compact SMD multilayer ceramic antenna has been chosen 17 An important note is that MICRF506 works at 2 5 V where as the MCU operates at 3 3 V Hence levels must be adequately translated to enable correct electrical interface between these two parts This is done by specialized circuits exist which allow bi directional communication An example of such circuits is the MAX3001E 18 from MAXIM For more details of electrical implementation refer to appendix E 5 4 3 2 IMPLEMENTATION OF A RF PROTOCOL Data exchange through MICRF506 is done using a bidirectional data line A RF protocol needs to be built in order to give a meaning to data other than a series of bits For this purpose a multilayer protocol has been developed Figure 4 3 depicts the different layers that compose the RF protocol Application lt to Data link e Physical layer Send and receive data Configuration Sampling data line Assign power mode User data Output on data line Pa
5. 30 energy flow in the device 30 global scheme 32 user task paso Fa e ba BES eu ae Q 33 storage task 34 display task E dia a fi La ambient 35 enerpy task isus s ionia e OR Ae e n di 35 flowchart of GlucoBox Software 2 39 GCODBlguratlOH ee 40 interaction with the 41 example of Labview implementation of the time update command 41 graphic display steps 42 developer s tab 43 mechanical parts used in GlucoBox assembly 46 top view of the main board 47 bottom view of the main board 48 top view of daughter board 48 GlucoBox displaying a reading 1 1 scale 50 temperature plot using GlucoBox software 51 power consumption over a period of 10 minutes 52 56 LIST OF TABLES 2 1 2 2 4 1 4 2 4 3 4 4 4 5 B 1 D 1 monitor requirements monitor requirements flash memory characteristics USB transceiver characteristics RTC graphi
6. 44 6 2 PCB layout sede Rebbe sus II Po EURO Ron 44 7 Tests and results 49 T Test Conditions s s 162 24 3 wo 9 4o 9 onc debit Roy ee bat 49 de Results ddd dem Gud dy psy dede Q A 49 8 Conclusion 53 8 1 Future work 53 8 2 Project conclusion 53 ii Acknowledgments 55 Bibliography 59 A Device Specifications 60 B GlucoBox User Manual 61 B 1 Safety Instructions 61 B 2 62 Battery Charger Safety 63 B 4 Charging The Battery 64 B 5 Location Of Controls 64 iene u Ld Ue i d PS 65 Connection GlucoBox Control Device To Your PC 66 C Technical User Manual 73 C 1 Software 73 C 2 Accessing programming interface 73 D Cost calculation 76 E Electrical Schematics 77 Mainboard 3 oos ewe a stan dee ha e 77 MOU 2 3484299 a w sez w Tam an RA 78 BL3 Periph rals 5522 2424 pe koc d omo eee Bad 79 E 4 Power Supply 80 B5 RP posa Rem ARR Pee SI a rane 81 E6 USB 24 222486 din a di a Bh XC RSS 82 E 7 Dau
7. 7 c2 100nF 100nF RI 10K CON_RF E e a Ul CS RE MAX3001E gt 1 20 sete ovu Zo a SCLK ovo en Pt a ID RF 4 lovis Evao 177 LD MOU 10 RF DATACLK RF 52 TOVIA lovaca 16 DATACLK_MCU DATAIXO RF iovis lovers 15 DATAIXO MCU DATAIXO RF IO RF 71 iovis lovers 1210 MOU gt SCLK_RF E lovee 3 SCK MOU gt DATACLK RF CS RF iovis 2 lovocs 12 CS MCU gt LD RE MAX3001E 2 RSSI 7 PIN F CON BASE eg e v gt 3 PIN M VCC VCC RF CON CS MCU 5 SCLK MCU 10 MCU 5 DATAIXO MCU sy DATACLK LD MCU RSSI 7 PIN M Title Size Number Revision A4 Date 14 02 2006 Sheet of File E Master Project Level_Shifter_ SchemdiDSohDBg HOSN3S YALAIHS 13447 F LOADING PICTURE IN DDRAM A Matlab function makes display data easier The developper must 1 create a black and white picture with the desired size in bitmap format 2 import the bitmap picture and run the function 3 copy and past the text from the output of the function to the C code 4 use the appropriate function to display the picture on the LCD commercial program for technical computing http www mathworks com 88 G RF PROTOCOL The aim of this section is to give details on how the RF communication is implemented The co
8. In order to identify the real needs of diabetics using such devices it is important to dis cuss with concerned persons For this purpose a discussion has been held with a nurse in diabetology from the CHUV With the help of her recommendations a summary of the important patient s needs are listed in the next paragraphs 2 2 1 USER INTERFACE The main requirement is to have a system which is easy to use Indeed both young and elder diabetics do not know necessarily how to manipulate technical devices The system must have a minimum number of buttons with a user friendly interface When a measurement is requested by pressing on a button the delay for the reading to be displayed must be as short as possible If rechargeable batteries are used the time between two charging must be as long as possible 2 2 2 EXTERNAL DESIGN The system must have more or less the same dimension and weight as a mobile telephone It should easily fit in a pocket or carried in a bag especially for women 3Mrs Irma Blanco CHUV Centre Hospitalier Universitaire Vaudois 5 93 GlucoBox System LPM EPFL III A watch format is not a good solution In European culture people suffering from a disease do not want that their situation is known as it is the case in other countries like USA Moreover not everybody wear watches or prefer their own one especially for women and sportsmen 2 2 3 DISPLAY Ano
9. LCD RS iN WR os NC RD mi pi Sou Wine ps LE IF 26 a is R21 LCD_SMD x Real time clock with backup power n vec vec vec JPINS BATTERY CS RTC 100nF que seg 11 Q SERMODE PF amp INTO CE INTI SCLK 4 SDI NC 6 Spo Ne LE NC xx us DS1305E RTC INT SPI Bus from MCU val CLOCKS ELOEK MOST MOSI MES MISO ND CS FIAT CS FLASH S LCD CS RIC CS RTC Tide GlucoBox SPI peripherals Drawn by Sadasing Kowlessur amp Damien Perritaz EPFL Laboratoire de Production Size A4 Number Revision 4 Mierteeimique TCOURPOISTECHRIQUE Date 14 02 2006 Sheet of 1 dina F D RALE DE LAUSANNE File EMaster Project PCH GlucoBox System 75 DEVICES SehDoc ST1VdaHdldad 08 Battery Monitor Voltage inverter for LCD backlight lt CHARGE STATUS LDO Voltage Regulator SHUTDOWN POWER_RF vec VCC RF u2 5 6 IN MAX88830UTA 7 SHDNA OUTB
10. 1lpmwww epfl ch nttp www idf org Radio Frequency 1 93 GlucoBox System LPM EPFL kzzwxzuaay _ 1 3 PROJECT OVERVIEW The proposed device is capable of requesting instantaneous reading of remote sensor via RF link and display measurement Values can be stored in the device itself Data can be transfered at any time to a personal computer PC for further analysis Figure 1 1 depicts the general principle of the control device Tasks such as scheduling measurements and loading parameters to the sensor are also possible bio sensor user control device Figure 1 1 general concept of the control device This project is held at EPFL as a winter master project which lasts for sixteen weeks The project is divided into four main steps finding solutions design and manufacturing software development and final tests As mentioned before this project is for a demonstrator bench so motivation is focused on the functionality of the device rather than its cost Hence there is apparently no cost constraints Furthermore industrialization aspects of the device are not taken into account in the design due to short duration of this project For the same reasons reliability electrical and medical compliances are not part of this project 1 4 PROJECT MANAGEMENT This project is multi disciplinary project It requires knowledge in electrical design me chanical design and programmin
11. 3 2 Implementation of a RF protocol 27 4 3 3 Software implementation 29 4 4 Power supply 30 4 41 Accumulator 30 4 4 2 Voltage regulator 30 4 4 3 Power management 30 4 5 Embedded software 31 AGA Mana tie di oe ake L A OS S SUS 31 45 2 User task au ak vi aca he Y ee o9 eo We aus a aa a 31 4 03 Storage Das os 31 4 5 4 Display task 22525 dedo opem es e ORG 32 4 5 5 Energy task eme a 8 s s h gua a w SUR RI eee 32 In order to achieve the functional requirements of the control unit the corresponding components for each task need to be wisely selected A wide range of components exists but our selection is based on two main criteria size and availability The main reason is that these criteria allow us to rapidly validate our concept Although these parts may not necessarily be the optimal ones they shall fit in our demonstrator application The next paragraphs depict in details the characteristics of each part 18 93 GlucoBox System LPM EPFL 4 1 ARCHITECTURE One of the important factors when choosing an architecture is to decide which MCU is the most suitable On the market there are a large number of MCU some are dedicated or optimized for special task After the MCU has been selecte
12. DC_PLUG DBS101G L Voltage regulator Powerstatus RI 270 VI DI LED VDD UL IN MAX88830UTA SHDNA SHDNB GND MAXSSS3 afl VCC 1 CoN2 2 CONI L3 lt 2 C2 C3 1 lt ap ow lt bi 1 lt 3 PIN F together SO goes to RF2 SDA SCLK goes to RF3 SCL Refer to MCU scheatic for more details This board has same layout for connectors as for sensor system bottom board For temperature sensor to work properly remove ic NQ chip and connect it s pads 6 and 19 CS is default pulled up R1 27k of MCU schematic and goes to RD1 os dsPIC Digital temperature sensor 4 CON C4 rt 100nF us 3 MAX6630 H anp so p x 5 C faz 1 34 vec sek MAXGG0 CENE cs C6 C7 IpF IpF IpF Tite GlucoBox Wireless temperature sensor module for functional proof Drawn by Sadasing Kowlessur amp Damien Perritaz Size A4 Number Revision 1 EPFL Laboratoire de Production Microtechnique LPM Mieratecknizie PM COLE POLYTECHNIQUE Date 14 02 2006 Sheet of 1 1015 Lausanne F D RALE DE LAUSANNE File E Master Project PCB Gluc
13. H SHDNB GND 2 MAXS883 C19 22w 10uF Tantalum capacitors E 2PINS HEADER Hi voltage tracks must be short as possible EXT RF VEXT VCC RF GND VBUS VBUS VBUS VEXT min 1A tracks required M BATE E vee Tantalum capacitors JPINS BATTERY 5 4 C16 2 2uF 2 2uF B U3 Inductor 1 10 LI 100pF AC zluss ce L2 2PINS_JUMPER_SMD X 8 14 SP4422A STATI 7 3 5 2 E ISET gt HON 2 7 gt vss ISETI 3 VSS S 1 BQ24022 co D 3 t 2 R7 ns SE LSk 10k cis 10uF a S Tantalum capacitor BACKLIGHT 5 Line pulled down GlucoBox Power Supply Drawn by Sadasing Kowlessur amp Damien Perritaz Size A4 Number Revision 3 Date 14 02 2006 Sheet of 1 EPFL Laboratoire de Production Microtechnique LPM CH 1015 Lausanne COLE POLYTECHNIQUE F D RALE DE LAUSANNE File E Master Project PCB GlucoBox System vIPOWER SUPPLY SCHDOC AlddNS 4AIMOd I8
14. RALE DE LAUSANNE E Master Project PCBiGlucoBox System VARE SCHDOC G8 lt USB R23 2 R R24 2 R VBUS VBUS R25 cas 10K R26 1 C47 ROT 470R 1 Il 100nF C46 JL 100nF 5 100nF DE te 6 TXD 3V30UT 5229 RXD RXD Zil USBDM lt 7 9 RIS USBDP CTS ve RSTOUT DIRE RESET FIDI 4 57 RESET DSR Y a T 57 DCD pss ras RI P P GND Ex 274 EEG TXDEN 1 gt EEK TXLED 31 EEDATA RXLED CSTCREM TEST PWRCTL PWREN4 SLEEP T D R28 FT232 a 10K ND VBUS VBUS VTC Tite GlucoBox USB to UART transceiver Drawnby Sadasing Kowlessur amp Damien Perritaz EPFL Laboratoire de Production Size A4 Number Revision 2 Microtechnique LPM COLETOISTEGHRTQUE Dac 13022006 Shu CH 1015 Lausanne F D RALE DE LAUSANNE File Project PCB G ucoBox System UART SchDoc gsn 934 8 External DC power source 5 6V 91A LED for charging status Push button for user interaction
15. depending on the number of data during this period the communication is lost the display n progress LED turns red The figure 5 5 represents three screenshots of the display initial view with a plot of acquired data and a zoom on a special zone 5 2 4 DEBUG TAB This tab shown in figure 5 6 is intended to developers only and is used to test and validate new commands between the computer software and the control device The command are sent as the same way as commands available in the user tab Data received from the MCU are displayed in different format byte array string boolean array 38 93 LPM EPFL CONFIG TAB GlucoBox System Configuration serial port save Open or create file for data storage STOP button DEBUG TAB DISPLAY TAB wa button USER TAB Other button YES Display graphic Y Export csv ransmission ransmissiori ransmission ransmission enable enable enable enable YES Send Request date and corresponding time send data command Send command and data Request data send command No Send error YES Send error Send error MES NO YE YES Sendis Wake uD NES Receive error Receive error Receive error packet NO Receive and display data if needed Receive and store data in gbx Display date and i F
16. e Low autonomy the current Wrist PDA watch has only 3 days of power with 30 minutes of use per day e Watch format for the reasons explained in section 2 2 2 it is not suitable 2 5 2 PCMCIA 4 A PCMCIA card can be used with many devices such as notebooks and PDA Developing this kind of card is possible A hardware design integrating a RF module must be done and corresponding driver must be coded ADVANTAGES e Same interface with computer or PDA a Palm or iPaq e Large choice of device The development could be done on a computer or a PDA DISADVANTAGES e Multi target development necessary e Dependency of a commercial product e Time required for writing a driver e Mechanical constraints for compatibility 2 5 3 OTHER DEVICES Lots of embedded systems exist It could be possible to adapt a MP3 player or mobile telephone for example Hardware and software part must be developed to integrate a RF module ADVANTAGES e Large choice of device e Attractive look for a demonstrator bench DISADVANTAGES e Multi target development necessary e High dependency of a commercial product e Generally developer tools not available PCMCIA Personal Computer Memory Card International Association 10 93 GlucoBox System LPM EPFL ee SEY 2 5 4 HOME MADE SYSTEM An other solution is to entirely develop a system It avoids limitations from another device to match the project requirements ADVANTAGE
17. evaluate the reaction after a change in the medication A tiny sensor is introduced under the skin of the abdomen After insertion the sensor is secured with tape to keep it in place A wire connects the sensor to the monitor generally held in the pocket The system automatically takes measurements every five minutes during a period of three days and stores them During this period the patient must continue to take his glucose level with a standard system because CGMS measurements are not calibrated this is done off line For this reason no measurement is displayed The monitor shown in figure 2 1 b is of size 90 x 70 x 22 mm and weighs 115 g Data are transfered to a computer via a serial cable A software is available for the doctor to In this report doctor is a generic term used for all healthcare professionals CGMS Continuous Glucose Monitoring System A 93 GlucoBox System LPM EPFL r _ ____________ _ _ _ii GG manage diabetics personal information and corresponding measurements Batteries used are non rechargeable ones and have two months lifetime The main advantage is that this low invasive device can automatically take measurements continuously for a long period of time Nevertheless this device can not be used for glucose level regulation Lo a Accu Chek Aviva b CGMS Gold System Figure 2 1 commonly used monitor devices found on the Swiss market 2 2 MONITOR NEEDS
18. is recommended by MICREL but other types of coding may also be used Interface with MICRF506 is done with the help of 8 lines as shown in figure 4 2 Descrip tion of each line is given below cS Programmin SCLK lt 9 l interface L Antenna L DATAIXO 4 Data DATACLK interface z LD gt I RSSI Status lines Figure 4 2 electrical interface of MICRF506 Programming interface The MICRF506 functions are enabled through a number of pro gramming bits The programming bits are organized as s set of addressable control registers each register holding 8 bits The control registers are accessed through a 3 wire interface clock input data bi directional and chip select input These lines are referred to as SCLK IO and CS respectively Data interface The data interface consists of a clock output as it is provided by MI CRF506 and a bi directional data These lines are referred to as DATACLK and DATAIXO respectively The data interface is defined in such a way that all user action should take place on falling edge of DATACLK Other lines Two more lines outputs are provided more information about the IC a lock detect pin LD indicates that the PLL 4 is locked and a RSSI analog pin gives the strength of the RF signal 230 is represented by a 011 transition and 1 by a 1 0 transition 24PLL phase lock loop more details in datasheet 26 93 GlucoBox System LPM EPFL Ta I
19. must be connected via USB or else an error dialog box will appear 3 2 2 USING THE INTERFACE The interface shown in figure 3 4 contains four tabs e User The user sees the time and date of the GlucoBox can manage data acquisition storage and erasing and change parameters date and time alarm volume automatic acquisition frequency and alarm glucose level e Config It is necessary to configure the communication COM port selection and baud rate choose before to initiate it The path for data storage can also be fixed e Display A graphic is proposed to show the glucose level evolution The user can choose to display either the current acquired data or import data previously acquired e Debug This tab is reserved for developers only 16 93 GlucoBox System LPM EPFL TO __t1nc_ew_ eo o oe rs l GlucoBox vi Figure 3 4 graphical interface 17 93 GlucoBox System LPM EPEL 4 CONTROL DEVICE Contents Architecture 4 3233 x w ko e RR e WU a 19 4 2 Embedded peripherals 20 4 2 1 Non volatile 20 4 2 2 USB transceiver 22 4 2 3 Time management 23 ADA Display 9 23 004 med E e e RR 24 42 5 Alarm Be fant ox MA E wx mourn Re xus 25 4 3 Wireless communication 25 4 31 MICRF506 overview 25 4
20. occurs the user can simply reboot reset pin hole the control device to restore the system s configuration 4 5 2 USER TASK The user task establishes the communication with the computer via the USB transceiver If there is a data transaction an interrupt occurs and the command is executed The command with its data is received from the computer and the corresponding command is executed The principal components of this function are shown in figure 4 9 The different commands will be explained in the chapter 5 which describes the PC software 4 5 3 STORAGE TASK The storage task is responsible for automatically acquiring measurement and storage Most of the time the MCU is in sleep mode and is waked up by the RTC alarm this triggers a communication with the sensor and fetch data The figure 4 10 shows this task in details 31 93 GlucoBox System LPM EPFL Boot or reset Initialization Boot function y RF Initialization User task y a Storage task L Y c t Display task Energy task Figure 4 8 global scheme 4 5 4 DISPLAY TASK The display task presented in figure 4 11 is responsible for the user interaction display is requested through the two buttons The green button is used to display a measurement and the red one for enabling disabling the audible alarm 4 5 5 ENERGY TASK The energy task manages power consumption of the co
21. receive process does not decode data stream correctly at this stage Optimize Level 3 for rf gen c is required in MPLAB C30 environment G 7 EXAMPLE 1 SENDING A PACKET include rf service h unsigned char test packet Saluti2345 unsigned char error void main void i RF Init Service 1 RF_Powerdown RF_Set_TX_Power 6 while 1 error RF Send Packet uint8 test packet RF COMMAND NOACK RF RECEIVER ADDRESS RF AUTO POWERDOWN ON DelayMs 2000 91 G 8 EXAMPLE 2 RECEIVING A PACKET include rf_service h unsigned char error k unsigned int sum void main void RF_Init_Service 1 RF Powerdown while 1 X error RF Receive Packet RF CHECK RSSI RF AUTO POWERDOWN ON 0 if error RF NO ERROR i sum 0 for k 0 k lt RF_Get_Payload_Length k sum RF_Get_Buffer_Pointer k F else t in case of error do something DelayMs 2000 92 H CONTENTS OF INSTALLATION CD GlucoBox 3 Drivers WinXP GlucoBox Development Catia Datasheet LabView PCB Report L Source Code SY GlucoBox Bench GlucoBox Firmware RF Bench C GlucoBox Software Directory Content Drivers GlucoBox Development GlucoBox Development GlucoBox Development GlucoBox Development GlucoBox Development GlucoBox Development GlucoBox Development GlucoBox Development GlucoBox Software WinXP Catia Datasheet LabVi
22. 0 100nF 2399 amp N zz 2 292 TI e222 E 9 2 Z Z pi GNDA TCNQ aa Jd sla dele VEC RI R2 27K 27K vec 9 SDA SCL Tile vee vec Sn veea MCU amp Sin D converter Size Number Revision CON3 A v 2 v V V Date 14 02 2006 Sheet of File E Master Project MCU_v2 SchDoc Drawn By Leandre Bolomey YOSNAS 6 4 NIN 98 HOSN3S OQL 3 dd GND VDD i IND ssp InF n Ee RI 6 2k P_Jj 5 10nF ad RT 1 10R SND al al 1008 l mani 2 Tsx 402 4 e mai R S 6 2 6 2 E n 8 E gt 6 9 2 PTATBES 2 Hb Ii 12 1 5pl RFVDD cs e 3 ice RFGND MICRE506 SCLK re n ay y 20 ANT MLF 32 10 O Q_V o AS D RFGND DATAIXO a ANT cs RFGND E DATACIK E add NBF 9 2 8 5 8 n 5 s DZ 5 z i NQ 5 6 5 NE gt o E GAZ GND RS k Tide Size Number Revision M Date 14 02 2006 Sheet of File E Master Project Projet Sdh Doc Drawn By 1 2 3 28 RF VCC
23. 2 FUNCTIONALITIES The functionalities are available for the user through four tabs with different usage Four LEDs give information about the state of the program they are described below in corresponding sections The main components of the program are shown in figure 5 1 5 2 1 CONFIG TAB This fields of this tab shown in figure 5 2 must be filled in correctly before beginning the communication with the GlucoBox control device 1 The correct port through which the control device is connected must be selected gen erally noted as ASRLX INSTR where X corresponds to the number of the COM port please refer to appendix B 7 2 for driver installation This product from National Instrument http www ni com is a graphical programming environment to build data acquisition and instrument control applications 36 93 GlucoBox System LPM EPFL UII scs J T 2 The baudrate correspond to the connection speed It can be changed by the user but must be compatible with the configuration of the MCU On current implementation the chosen baudrate is 476 kbits per second 3 The program gather data and store them in the user defined save path This path must be valid prior to saving data After all theses fields have been correctly filled in the configuration button must be ac tivated and only then functionalities may be used The configuration LED toggles
24. C IC USB transceiver FTDI IC resonator 6 MHz flash memory 00009 buzzer alarm 3 miscellancous IL ND Co 2 connector 14 resistor capacitor 8 Table D 1 cost of the GlucoBox components 76 LL n 16 15 n 13 12 10 POWER SUPPLY VEXT POWER SUPPLY SCHDOC IT VEXT L vec VCC_RF VBUS VC Wii VCC RF CHARGE IN PROGRESS CHARGE STATUS m GND VBUS VCC USB UART USB UART SchDoc vec DATA USB DATA 5 m GND DATA DATA EMUC EMUD GREEN BUTTON E MMSMDI 6 CHARGE IN PROGRES MCLR VEXT vec Mou MCU SchDoc LIV BAT j gt BAT BACKLIGHT amp C_ BACKLIGHT L vBUS SHUTDOWN POWER RF lt SHUTDOWN POWER RF GPI gt sop gt Pac PGD e EMUC Y E m x EMUD RED_BUTTON GREEN BUTTON RED BUTTON lt GREEN BUTION RESET FIDI C RESET FIDI RXD n nx gt mp 7 RF SCHDOC RF RSSI C C RE RSSI vcc RF RFID lt RFID RF DATA CLK RF DATA RF DATAXIO lt gt _ gt RF DATAXIO RF 10 DD RF 10 RF SCLK RF SCLK RFCS gt RF CS SPI DEVICES SPI DEVICES SchDoc CLOCK 7 4 gt CLOCK vcc Cd MOSI gt MOSI MISO MISO CS RTC gt gt CS RTC CS LCD gt CS LCD CS FLASH FO CS FLASH LC
25. CD or on the Windows Update Web site with your permission Can Windows connect to Windows Update to search for software O Yes this time only d every time connect a device Click Next to continue p Choose No not this time and click on Next Found New Hardware Wizard Click Next to continue This wizard helps you install software for USB Serial Port If your hardware came with an installation CD S or floppy disk insert it now What do you want the wizard to do Install trom a list or specific location Advance Choose Install the software automatically and click on Next 63 Found New Hardware Wizard Please wait while the wizard installs the software Aa wes E USB Serial Port lt E FTLang dll To C WINDOWS system32 Found New Hardware Wizard Completing the Found New gt Hardware Wizard The wizard has finished installing the software for 3 USB Serial Port Click Finish to close the wizard gt Click Finish to end installation You should a confirmation in your task bar Found New Hardware x Your new hardware is installed and ready to use amp Rhymezone assembl mm 69 B 7 3 VERIFY CORRECT INSTALLATION OF DRIVERS Launch WindowsXP device manager Windows Key Pause or right clic
26. D RS D gt LCD RS LCD RES _ gt LCD RES RTC INT C RTC INT GND A GND C GlucoBox Entire system Draw by Sadasing Kowlessur amp Damien Perritaz EPFL Size A4 Number Revision 4 Laboratoire de Production Microtechnique LPM CH 1015 Lausanne Date 14 02 2006 Sheet of 1 ul COLE POLYTECHNIQUE F D RALE DE LAUSANNE File _E Master Project PCBYGIuco Box System vIGLUCOBOX SYSTEM SCHDOC L3 QqavoaNIVIN SOILVIN3HOS 1V91419314 82 NOW c3 1 2 3 4 T cs 100nF a a 8 2 A 8 E 2 5 4 RI PPE SES C6 CR IpF IpF alla Lea pas dsPIC30F40 11 QEN 2588 8 245822 gage gt 22299 aves 8 2428 82255 3 AZZ e S d 7 ES 32 enr LE R4 28 Z osczcikorcis 2 ES 470R z 98 OSCI CLKIN LED BZ MISO a ga vss 7 9 z a VSS PGC PGC EMUC UI RXISDI 1 SDA RF2 U2TX CNI8 RES 52 VDD Tm U2RXICNI RF4 VDD a PP lt RESET FIDI 24 CTXURFI a RS gt NA G
27. K is sampled to ensure that only actions on falling edge are made G 3 MAIN SERVICES All necessary functions needed to use the RF protocol are defined in the file rf service c By including rf service h in a main program one can access to the functions below 89 RF Init Service initializes IO lines set priority of interrupts only argument to specify in this function and programs MICRF506 with default configuration RF RX Mode and RF TX Mode toggles between receive or transmit active modes of the RF IC TX Power RF Powerdown Mode and RF Standby Mode allow power management of MICRF506 RF_Set_Local_ID and RF_Set_Local_Address enable changing current default local parameters though this is not recommended RF_Get_Sender_Address RF_Get_Sender_ID and RF_Get_Frame_Type give access to data extracted after a successful reception RF_Get_Buffer_Pointer returns a pointer to access payload with the number of bytes to read given by RF_Get_Payload_Length Furthermore RF_Send_Packet and RF_Receive_Packet are two essential functions to initiate communication They are described in next sections G 4 TRANSMIT PROCEDURE To transmit a packet over RF just call RF_Send_Packet and provide necessary parameters a pointer to the data buffer to be sent the number of bytes in this buffer to be sent the type of the packet the recipient s address last parameter to automatically power down after transmission or not After all bein
28. LS DC outlet LCD screen Push buttons A green and B red Note if reset of the device is required press the RESET hole using a pointed object such as a safety clip 64 B 6 DISPLAY The display is divided into three zones p Measurement In this zone glucose level values are displayed Units mmol l are not displayed gt Date amp Time Date and time are displayed in this area b Icons Status of the device is displayed in this zone The icons and their corresponding signification are listed below Icon Description 200 battery level indicator alarm indicator memory full general failure indicates whether sound is activated or not RF communication is in progress communication between device and PC has been established automatic measurement acquisition Table B 1 icons displayed on top part of LCD screen 65 B 7 CONNECTION GLUCOBOX CONTROL DEVICE TO YOUR PC The drivers must be installed prior to using GlucoBox software B 7 1 SYSTEM REQUIREMENTS e Pentium 200 MHz or greater e 256 Mb or RAM e Windows XP e VGA 800x600 or above e 100 Mb of available hard disk space e CD ROM drive 2x speed or greater e USB 2 0 port 1 1 not supported B 7 2 INSTALLING DRIVERS p Insert the installation CD into your CD ROM drive gt Plug the USB cable into your PC and to GlucoBox control device Windows XP should
29. Master Project N LPM IPR STI COLE POLYTECHNIQUE F D RALE DE LAUSANNE Winter Session 2005 2006 by J derlayin progrese is eem Damien Perritaz Professor Peter Ryser Assistants Eric Meurville L andre Bolomey ECOLE POLYTECHNIQUE F D RALE DE LAUSANNE POLITECNO FEDERALE DI LOSANNA EIDGEN SSISCHE TECHNISCHE HOCHSCHULE LABORATOIRE DE PRODUCTION MICROTECHNIQUE COLE POLY TECHNIQUE F D RALE DE LAUSANNE TRAVAIL PRATIQUE DE MASTER Microtechnique Titre du travail GlucoBox System Candidat Damien Perritaz Section Microtechnique Professeur Prof Peter Ryser Assistants Eric Meurville L andre Bolomey Enonc Lorsqu il est implant dans un patient le capteur de glucose du LPM est contr l par un transceiver positionn proximit du site d implantation Il est pr vu que ce transciever soir lui m me contr l travers une liaison RF par un boitier externe avec afficheur et boutons de contr le Outre sa fonction de contr le programmation de la fr quence des mesures de glyc mie programmation des seuils d alerte et des alarmes acoustiques et tactiles ce boitier assure aussi la fonction d un data logger capable d enregistrer toute une s rie de mesures de les traiter calculs de tendance et de les visualiser A terme l interop rabilit avec un PC ou un
30. PDA devra tre assur Ce boitier de contr le sera aliment par batterie Il devra tre compact et un soin tout particulier sera port quant l esth tique du boitier Il aura pour coeur un dsPIC de Microchip et la partie RF sera reprise d un projet pr c dent Le but de ce travail est de r aliser int gralement ce boitier de contr le lectronique logiciel et design En outre les tudiants tabliront d une part la sp cification du protocole de communication RF entre le boitier de contr le et le transceiver et d autre part contacteront des patients ainsi que du personnel soignant pour laborer un cahier des charges fonctionnel de l appareil Remarques Le candidat tablira un planning de travail qui sera discut la fin des deux premi res se maines de travail Ce planning comprendra des ch ances dates fixes qui seront l occasion de faire le point sur l avance du travail et permettront ventuellement de modifier la d marche en fonction des objectifs atteindre Un rapport dactylographi en 3 exemplaires comprenant en son d but l nonc du travail suivi d un r sum d une page sera remis le 24 f vrier 2006 12 heures au plus tard La couleur n est tol r e que sur des sch mas qui ne seraient pas lisibles en noir Un r sum d une page sera tabli selon le canevas pris sur le serveur du LPM et remis s par ment au professeur images et figures en noir et blanc il sera dit dans une brochure Une d fe
31. PI 5 25 CRX RA ANSRBS 527 b 2 2708 ANTIRBT ANGOCFA RB6 X ANSQEBICNCNIRBS 22 VDD 558 AN4QEAICTICNGRB4 f RF DATAXIO gt E lt 85 VDD 66 R6 Z Q8 RF RSSI c 5 de ok 2 cu C12 a ze 5 36 InF InF a zz m ee x lt 25 58 55 28 FLASH PWMSHRES SS 4 88 Z Hi PWMGLRE 2 2 B BH 82 lt C LCD PWM2H REZ Z lt lt 2 GH lt lt vec ef ld s VEC R3 BACKLIGHT BATF GND lt SHUTDOWN POWER RF 10K R29 n Fa x 10K iH mw 2 ae 2 2 ok K E es 4 Lu GlucoBox Processor LAF 100nF 3 cp vec Drawn by Sadasing Kowlessur amp Damien Perritaz EPFL TOR Laboratoire de Production MW 4 4 Sie A4 Number Revision 3 ET Dater 1432 2006 Sheeri of 1 1015 Lausanne FEDERALE DE LAUSANNE File Easter Project PCB GlucoBox System vIIMCU SchDoc 1 2 3 4 62 Flash memory veevee vec vec RI7 Ris imo i C36 10K WK Ca NASPEO MOSI ilo CLOCK zie ot FLASH TE Se w g 3 2 u Restt gt waspeso Dot matrix LCD backlight power not included vec vee vec pu R20 _ 10K CS LCD 52 15 CLOCK 5 sip 16 MOSI 4 NC RES LCD RES T NC RS
32. S e Complete knowledge of the system without intermediate black boxes e Not dependent on a commercial device It is better for a long term basis e Only two targets in software development computer and control device e All mechanical parts fit in a unique enclosure e Only necessary components used this allows simple optimization for longer autonomy e Format autonomy could be freely chosen DISADVANTAGES e Development is longer in case of a demonstrator bench e Difficult to have a small and attractive device e Cost of development is generally high 2 5 5 SELECTED SYSTEM As seen above the best solution is to develop entirely a new system Indeed a custom made system simplifies the communication link between the sensor and the PC as depicted in figure 2 2 all other solutions require an additional interface to communicate with the control device as shown in figure 2 3 Consequently as there is less software development constraints in the home made solution this allows more flexibility for optimizations On the other hand a home made solution requires more hardware development but this is the price to pay for developing a more efficient hardware design Indeed in a home made solution it is easier to restrict components to functional requirements only thus the system will be energetically effective Finally our proposed custom made solution will use the USB port as it is widely present in almost all PC The con
33. and headers After taking into account all the rules the two PCB have been designed they are shown in the following figures All schematics can be found in appendix E 45 93 GlucoBox System LPM EPFL w e 1 base 4 main board PCB 7 LCD display 2 daughter PCB 5 support for push buttons 8 top cover 3 battery 6 push buttons 9 top lid Figure 6 1 mechanical parts used in GlucoBox assembly 46 93 GlucoBox System LPM EPFL n IO s M a _ 1_ _ _ GG 1 MCU dsPIC30F4011ML 2 USB to UART transceiver FT232BQ RTC DS1305E 1 7 Power management IC bq24022DRC 2 3 4 Non volatile memory M45PE80VMP 5 6 Voltage regulator MAX8883EUTAQ Piezoelectric sound transducer 0 Multilayer ceramic SMD antenna RF transceiver MICRF506BML 1 Level translator MAX3001E 2 Connector to daughter board Voltage inverter SP4422A T 8 9 1 1 1 Figure 6 2 top view of the main board 47 93 GlucoBox System LPM EPFL 1 LCD connector 2 Ground plane Figure 6 3 bottom view of the main board K E Gloco8ox Extension K S 8 D P e Len v2 2 13 01 2006 1 DC connector 4 USB connector 2 Bridge rectifier 5 Reset button 3 Connector to main board 6 Programming connector Figure 6 4 top view of daughter board 48 93 GlucoBox System LPM EPFL 7 TESTS AND RESULTS C
34. ation The RTC will use primary source to power itself GlucoBox being generally powered at all time Nevertheless in case on main power loss a backup battery in the form of a large value ca pacitor 0 2 F is required to keep the RTC working This type of source is very compact and can provide sufficient energy for about a week according to equation 4 1 which is sufficient for our application Calculations are based on 9 Electrical implementation is provided in appendix E 3 Vbacku min Vbacku min time In Ferri er Capacitor Voackupl max Ivackup max 1 3 3 3 ln 5 X 10 6 x 0 2 600 000 s z 167 h 7 days 4 1 SOFTWARE The RTC can be configured by accessing special registers in the IC via the SPT interface To setup up the RTC the following steps are made 14RTC real time clock 23 93 GlucoBox System LPM EPFL 1 Sr mm ms l7 e When the RTC is powered to the first time the oscillator is locked The oscillator will run after the control register has been correctly written to e Enable alarm by writing to the status register e Configure the super capacitor charge by writing in the trickle charger register Time information can be read at any time in the corresponding registers of the RTC The format used is specific and is not suitable as a time stamp A function that converts to readable format has been implemented The time stamp is then represented by a set of 7 bytes containing correspo
35. automatically detect a new hardware and will start installation process Found New Hardware Wizard Welcome to the Found New RS Hardware Wizard N Windows will search for cument and updated software by looking on your computer on the hardware installation CD or on the Windows Update Web site with your permission Read our priv Can Windows connect to Windows Update to search for software O Yes this time only Yes now and every time connect a device Click Next to continue p Choose No not this time and click on Next 66 Found New Hardware Wizard This wizard helps you install software for USB lt gt Serial lf your hardware came with an installation CD S or floppy disk insert it now What do you want the wizard to do location Advanced Click Next to continue gt Choose Install the software automatically and click on Next Found New Hardware Wizard w Completing the Found New Hardware Wizard gt The wizard has finished installing the software for USB Serial Converter Click Finish to close the wizard f p Click on Finish to continue 67 r Found New Hardware Wizard Welcome to the Found New Hardware Wizard Windows will search for cument and updated software by looking on your computer on the hardware installation
36. cal LCD module characteristics piezo ceramic alarm characteristics icons displayed on top part of LCD screen cost of the GlucoBox components 57 21 22 23 24 25 65 76 BIBLIOGRAPHY 1 2 10 11 12 13 Roche Diagnostics ACCU CHEK product information http www accu chek ch page visited Febuary 2006 Medtronic MiniMed CGMS product information http www minimed com professionals products cgms page visited Febuary 2006 Fossil Wrist PDA product information http www fossilwristpda com page visited Febuary 2006 PCMCIA product information http www pcmcia org page visited Febuary 2006 MICROCHIP dsPIC30F4011 product information http www microchip com stellent idcplg IdcService SS_GET_ PAGE amp nodeId 1335 amp dDocName en010337 page visited Febuary 2006 ST M45PE80 product information www st com stonline products families memories fl_ ser m45pe80 htm page visited Febuary 2006 FTDI FT232BQ product information www ftdichip com Products FT232BM htm page visited Febuary 2006 MAXIM DS1305 product information www maxim ic com quick view2 cfm qv pk 2686 page visited Febuary 2006 MAXIM Calculator for time keeping http www maxim ic com appnotes cfm appnote number 3517 page visited Febuary 2006 ELECTONIC ASSEMBLY PSEL 22 product information http www lcd module de deu pdf zubehoer el inverter pdf page visi
37. cket structure HOST I TRANSCEIVER Figure 4 3 description of protocol for MICRF506 MICRF506 In the host part contains two layers the Data link is responsible for interfacing with the MICRF506 via dedicated electrical lines and the Transport layer handles data at a higher level Indeed this layer is an essential part of the protocol as it ensures correct translation of low level data and hands it over to user application Furthermore the Transport layer provides primitives to access the transceiver Finally in the user application several routines are available to easily exchange data over RF and control running state of the transceiver This implementation is quite common to a wide range of protocols Indeed protocols are structured in layers in order to give higher level of abstraction on upper layers Each layer can be considered as a black box with inputs and outputs If a black box must be modified it does not affect upper nor lower layers it is obvious that inputs and outputs must not be altered A typical example is the Data link which is implemented according to the transceiver and host employed if another transceiver is used only the Data link is to be reprogrammed 25SMD Surface Mounted Device 27 93 GlucoBox System LPM EPEL FRAME STRUCTURE Packets sent over RF are divided into blocks as shown in figure 4 4 In our case a maximum of 20 bytes are sent per packet in reality due to Manchester encoding overhea
38. d the peripherals in the form of an IC must be chosen according to type of interface available on the MCU For the MCU the dsPIC30F4011 5 has been chosen for several reasons It is readily available It exists in small package form e This MCU is commonly used in the LPM laboratory in fact the actual bio sensor is built with this MCU and hence all hardware and software tools are immediately available another non negligible aspect is that at the LPM there is a good background on this MCU By using the same MCU as in the bio sensor code portability and integration are easier e The MCU has enough lines and modules required in our application Another important feature of the dsPIC30F4011 is that it incorporates an internal oscilla tor the latter can be configured to deliver sufficient computing power with a good comprise on power consumption Furthermore it can operate at 3 3 V which is a common voltage for low power devices The next step is to choose the peripherals compatible with the MCU and 3 3 V More over the SPI has been chosen as interface with the peripherals for its ease of use and its performance In order to achieve functional requirements of our project the following peripherals are necessary e a display with back light e a time management circuit to assign time stamp to each measurement and to allow scheduling of readings e a non volatile memory to store measured values wi
39. d twice that number of bytes are sent The roles of each block are explained below 11 to 20 bytes Frame level 1 Preamble Sync Length Payload level 1 1 17 6 15 E r r7 CRC 16 computation source I eee o I Y Frame level 2 Payload level 2 Sender s ID Sender s address Recipient s address CRC value 1 10 LA 12 LT I u 7 I I Frame level 3 Payload level 3 0 9 LA Figure 4 4 structure of the frame values indicate size in bytes Preamble At the beginning of a received data packet the bit synchronizer clock frequency is not synchronized to the bit rate The equivalent time of a minimum number of 22 bits are required before synchronization is achieved In our application more bits are used so that receiver in search mode can sample correctly RSSI level Sync Data received is merely a bit stream without start nor end parts This byte allows receiver to identify where is the start of the packet Length This byte is necessary to inform receiver how many bits is expected in the packet The value must be in the allowed range of frame structure 6 to 15 or else rest of packet is ignored Sender s ID and Address The sender has two parameters which help to identify it Its identification ID is a value that represents the class of equipment to which it belongs at this stage only one ID is used other values will be allocated in the future and its address must be unique in each clas
40. d as a result lead to the final product In this scope some improvements are essential for a key success e Mechanical aspect re design the enclosure so that is can meet medical regulations This part will also be profitable to improve external look Electrical as for mechanical aspect medical conformity is essential One of the main part here concerns the wireless link New IC must be prospected in order to respect medical regulations e PC software portal to common OS like MAC OSX or Linux Global study to reduce cost of development a broader study should be performed Cur rently costs of components of GlucoBox control device are relatively high around 300 CHF details in D New technologies fabrication processes and assembly techniques must be adequately chosen to achieve lower costs thus making the system affordable to diabetic patients Lausanne February 24 2006 Sadasing Kowlessur Damien Perritaz 54 93 ACKNOWLEDGMENTS During the realization of this project we were kindly guided and helped by many persons We would like to thank these persons for their support and advice e Mr Eric Meurville and Mr L andre Bolomey both from the LPM laboratory our assistants for this project e Mr Jean Frangois Zurcher LEMA EPFL who kindly gave us practical advice on RF designs e Mr Corradini Giancarlo LPM EPFL who helped us to mount our PCB components e Mrs Irma Blanco CHUV for her precious information
41. de applies to a dsPIC30F4011 micro controller MCU If another device is used please set IO pins accordingly In the following sections only important remarks are made For more information consult corresponding source code file Common definitions and constants are in rf defs h G 1 IO LINES To interface the MICRF506 a total of 8 lines are required 7 digital and 1 analog for more details refer to MICRF506 datasheet These lines are defined in rf_io_dspic h Additional functions to set directions of bi directional lines are also available in rf_io_dspic c The RSSI signal is used to detect incoming signal In the case of the dsPIC30F4011 the ADC must be correctly configured in main program Detection threshold level is set in rf_defs h under definition RF_RSSI_THRESHOLD G 2 DATA LINK Routines available in rf_gen h allow proper interfacing between MCU and RF IC Wave forms of required signals are given in the MICRF506 datasheet Functions RF_WriteSingleRegister and RF_ReadSingleRegister enable writing and reading to internal registers of the MICRF506 To exchange data over RF the DATAIXO and DATACLK of the MICRF506 are used The DATACLK is controlled by the MICRF506 and the data interface is defined in such a way that all user actions should take place on falling edge of DATACLK In the case of the dsPIC30F4011 the Change Notification CN interrupt is used In the corresponding inter rupt service routine ISR the DATACL
42. e data terminal equipment On the other hand the MCU can communicate directly to the PC by simply sending data using its UART module Bin fact this port is a virtual port as host program thinks it is a usual communication port this abstraction from the real port is provided by installed drivers 22 93 GlucoBox System LPM EPFL Ta MM M e 4 2 3 TIME MANAGEMENT The date and time must be known for time stamping measurements and for patient general information A software implementation on the MCU can be done but it will constantly need processor resources preventing the MCU to enter power saving mode A more efficient way to save energy is to use an external device for time keeping it usually consumes much less energy than the MCU this is the role of a RTC 4 In our application a RTC with its own power management is required Nowadays this criterion is commonly implemented However more features like programmable wake up electrical interface size and availability restricted our choice The DS1305 8 from MAXIM has been chosen for its characteristics namely those shown in table 4 3 RTC Reference DS1305E Interface SPI Time resolution seconds Power management auto select from primary or backup source Voltage 2 0 to 5 5 V Timekeeping current 1 LA Package TSSOP 20 Dimensions 6 4 x 4 4 mm Table 4 3 RTC characteristics HARDWARE This IC needs a precise 32 768 kHz crystal refer to datasheet for more inform
43. e used by both the doctor and the patient the latter being the end user The doctor can access advanced features of GlucoBox only by means of the computer software 3 1 1 EXTERNAL ASPECT The control device will be in a small form factor near the size of modern cellular phone The main interface of the device is composed of a large LCD screen and two push buttons as illustrated in figure 3 1 The enclosure is a molded black textured ABS case External dimensions are also given Display is also back lighted making it possible to read values in dark circumstances Other information such as battery level RF link and warnings are also available in the form of icons in the top part of the screen Push buttons are large enough and require a minimum pressure to be closed this prevents unexpected action from user when GlucoBox is placed in bag for example The overall weight of the device does not exceed 115 g LCD Liquid Crystal Display ABS Acrylonitrile Butadiene Styrene is a common thermoplastic used to make light rigid molded prod ucts 13 93 GlucoBox System LPM EPFL r __ r rr i M ri 62 Figure 3 1 GlucoBox dimensions in mm 3 1 2 MANIPULATIONS One of the most frequent tasks that the patient will perform is requesting an instantaneous measurement This is simply done by pressing once on button If the sensor is within range a value is then displayed note that the aerial icon i
44. eneral values alarm level should be configurable differently for each patient Below the normal range the patient must take rapid sugar When the blood glucose level falls below 2 mmol l there is a risk of coma Hypoglycemia alarm is especially important during the night or during sport An hyperglycemia has no instantaneous impact but is dangerous in the long run it can generate angiopathy Hyperglycemia is generally not detected by the patient an alarm can reduce the risk of complications Generally alarm on medical devices such as insulin pump are audible vibrating and visual However even though the patient should have the possibility to deactivate if desired some alarms must continue to operate disease of the blood vessels 6 93 GlucoBox System LPM EPFL eo mans vO 2 2 6 COMPUTER LINK A communication with a computer is used for data transmission and analysis The majority of current systems needs an intermediate device for data transfer such as a docking station This intermediate device should be avoided direct link is preferable 2 3 COMPUTER INTERFACE NEEDS A user friendly interface must be available on the computer to manage the communication with the device This interface can be used by both the patient and the doctor but only some functionalities are reserved for the doctor 2 3 1 PATIENT INTERFACE The interface should principally offer the opportunity to download and store the data and display a gra
45. eveloper s tab 43 93 GlucoBox System LPM EPFL 6 HARDWARE DESIGN Contents 6 1 Mechanical 44 6 2 PCB layout 2222 22 2 oh w w qaq dus que me ee 3 y 44 Once all the components have been selected the design can start There are two main aspects e Mechanical Main constraints are placement of components which are visible from outside of the case In doing so the size and the form the PCB will be defined e Electrical Once the dimensions of the PCB are defined the layout of all electrical components can be made It can be noted that the first part can be refined if additional constraints are revealed in the second part For this reason this approach is not strict and backward re definitions may be necessary 6 1 MECHANICAL A common ABS plastic case has been chosen to contain all components We have taken advantage of the presence of the battery room to fit all necessary connections namely the programming connector Hence the latter can be easily accessed by simply removing the lid Figure 6 1 shows in details on how all the mechanical parts are assembled in the GlucoBox However this accommodation of the connectors imposed the use of two separate PCB referred to as main board and daughter board Each of them was defined by the maximum place available in the assemblage and are interconnected through a multi way flat cable 6 2 PCB LAYOUT Before designing a PCB i
46. ew PCB Report Source Code GlucoBox Bench Source Code GlucoBox Firmware Source Code RF Bench 93 Drivers for GlucoBox Control Device Mechanical drawing files General documentation LabView files for PO software Protel DXP 2004 files used for PCB design IATEX files of this project including pictures Files to build a new firmware C code Current release of firmware Files to test RF part only C code Installation files of GlucoBox Software
47. from red to green to confirm that the configuration has been done The configuration parameters are fixed as long as the program is running To change parameters the user must first stop the application with the corresponding button The transmission enable check must be set for data transfer the corresponding LED shows its state In case of communication failure this check can be disabled then re enabled to restore the communication 5 2 2 USER TAB When the configuration is done and the transmission enable the user can interact with the control device The interaction This tab contains three parts shown in figure 5 3 1 Time management If no other functionality is used the program automatically request the GlucoBox date and time every 100 ms The user can also update the time if it is wrong due to too long inactivity period for example 2 Parameters setting The acquisition frequency alarm volume and the two glucose level thresholds can be set separately 3 Data management The data acquired by the GlucoBox can be download and stored in the computer The download time depends of the volume of data to transfer a progress bar informs the user of the transfer state An abort button is also available All the data stored in the GlucoBox can be erased if the corresponding button is activated The raw data acquired are saved with the date as name example 23 02 06 gbx Note that the gbx extension has been created for this applica
48. g The work is lead by two students both are from Micro engineering section and have the necessary background to tackle each aspect of the project In this context no specific field was assigned to each student Indeed all the three fields are closely linked one to another and hence the steps mentioned above were achieved on a combined effort basis 2 93 GlucoBox System LPM EPEL 2 BASIC CONCEPTS Contents 2 1 Stateofthe art 225 wow whe ae w Re UR S XO dupe 4 21 1 Accu Chek 4 212 CGMS 4 2 22 Monitor needs s sore w 3 34 s 5 2 2 1 User 5 22 2 External design iu 24 2 a i 5 2 2 9 Display pa RES Oe 6 2 2 4 Measurements 6 22225 Alari Bone ED Xo dod LE da Wes eR eee ee dame 6 2 2 0 Computer link ius oed S REE Be oem e ETE 7 2 3 Computer interface needs 7 2 9 1 Patient interface sa wi edo e bow RU SU d 7 2 3 2 Doctor interface 7 2 4 Project requirements 7 2 5 Suggested solutions 8 251 Wrist PDA 8 292 PONMGIA by di SEA SI Ain 10 2 5 3 Other devices 10 2 5 4 Home made system
49. g encoded and put into a buffer data is sent by activating CN interrupts Finally a flag is set to inform user that all data have been sent A length error code is returned by RF_Send_Packet if the number of bytes to sent exceeds that defined by frame structure G 5 RECEIVE PROCEDURE Data can be received simply by calling RF_Receive_Packet The main problem of a reception is to know whether there is an incoming signal This is the role of the RF_CHECK_RSSI option If no signal is present RF_Receive_Packet will be automatically ended On the other hand if the RF_SKIP_RSSI option is used instead and no signal is present then RF_Receive_Packet will constantly seek for a SYNC The only way to force terminating this process is to modify an argument passed to this function An example of how to modify this variable is by using a interrupt source such a timer period match that sets the argument to a value different from 0 As in the transmit packet function error codes are also output here Errors include 90 e RF_MANCHESTER_ERROR e RF_LENGTH_ERROR e RF_CRC_ERROR e RF_ADDRESS_ERROR e RF_RX_TIMEOUT e RF_RSSI_ABSENT Moreover additional argument can automatically set RF IC to power down mode after reception G 6 FIRMWARE LIMITATIONS This version of RF protocol implementation has some limitations These are e MICRF506 setup is defined once at compilation level in rf setup h e optimization for low level routines is required or else
50. ghter board 83 E 8 Temperature Sensor Base 84 E 9 Sensor MOU 34 wise wasu Sa led SS we a 85 k 10 Sensor RE ogg re dese Aa Pais ak a 86 E 11 Sensor Level Shifter 87 F Loading picture in DDRAM 88 G RF Protocol 89 Gioie siria e ei 89 1 2 Data nk x dogs Somos d eu Qum ai 89 Main services 89 G 4 Transmit 90 G 5 Receive procedure 90 G 6 Firmware limitations 91 Example 1 sending a packet 91 G 8 Example 2 receiving a 92 H Contents of Installation CD 93 iv GlucoBox System LPM EPFL 1 INTRODUCTION At the LPM laboratory a bio sensor is currently under development The main goal of this sensor is to measure glucose level in blood by using a totally innovative method The main application of this sensor is for diabetic patients who need glucose level monitoring 1 1 WHAT IS DIABETES Diabetes is an illness which occurs as a result of problems with the production and supply of insulin in the body Without insulin our bodies cannot obtain the necessary energy from our food Insulin is made in a large gland behind the stomach called the pancreas At present there is n
51. ging indicator LED see figure 3 2 Charging can be done by plugging in a DC source maximum 6 V Polarization in not important as GlucoBox accepts either case The device can also be charged via the USB port For more specifications on power supply refer to appendix A Programming connector DC plug Figure 3 2 view of connectors of GlucoBox Another important link is the RF wireless connection With its built in antenna Glu coBox is able to communicate with the remote sensor PROGRAMMING INTERFACE The control device possesses also a special connector to be used for firmware upgrade Indeed this special port accessible by removing the front lid see appendix C 2 for more details allows technical user to upload firmware by using an appropriate programmer The figure 3 3 gives the pinning of the port in details 3LED Light Emitting Diode 15 93 GlucoBox System LPM EPFL Figure 3 3 details of programming connector 3 2 COMPUTER INTERFACE The GlucoBox program communicates with the control device to download data stored in it A graphic shows the evolution of the glucose rate during the acquisition period The software gives also the possibility to set up some parameters of the GlucoBox 3 2 1 RUNNING THE INTERFACE The interface is an self executable running on Windows The required specifications for using this application are presented in the appendix B Before launching this application the GlucoBox
52. gure 4 7 can be divided into three items portable electrical accumulator power supply regulation and power manager for external electrical energy source ou extemal power regulator EDITED gt Sg am T Figure 4 7 energy flow in the device system 4 4 1 ACCUMULATOR A Lithium polymer type battery has been chosen to provide sufficient energy to our system This type of battery has superior capacity compared to other types of batteries with same size and weight Moreover it can easily be found in compact slim form The model used is for our system is a 1500 mAh running at 3 7 V from Kokam 21 It fits our enclosure and has sufficient capacity to power our system for a minimum period of time 4 4 2 VOLTAGE REGULATOR Our system requires two different voltages 2 5 V for RF chip and 3 3 V for the rest Moreover these voltages will be provided from the battery which is only at nominal 3 7 V Hence a low dropout regulator is necessary An IC from Maxim 22 has all needed characteristics in a single compact package the MAX8883 can deliver up to 160 mA on each voltage channel 4 4 3 POWER MANAGEMENT A dedicated IC exists that matches exactly our needs it s the bq24022 from Texas Instruments 23 It has the capability of handling two sources for charging Lithium polymer batteries or 30 93 GlucoBox System LPM EPFL III M 0s 717 Lithium Ion Indeed it can automatica
53. igure 5 1 flowchart of GlucoBox Software 39 93 GlucoBox System LPM EPFL rr GlucoBox vi ASRL3 INSTR i 476000 D GlucoBox Data Figure 5 2 configuration 40 93 GlucoBox System LPM EPFL GlucoBox vi Figure 5 3 interaction with the GlucoBox buttons selection transmission management corresponding command write error test time acquisio function time and date formatting serial write function ee TOTTI ET cun z pedites Figure 5 4 example of Labview implementation of the time update command 41 93 GlucoBox System LPM EPFL i GlucoBox vi x GlucoBox vi x CD configuration CY display in progress CD configuration display in progress CD ransmission enor im CD tansmission SUM User Config Display Debug User Config Display Debug Gimme me Glucose level Glucose level BEI 144 2 i 5 1004 010000 01 00 01 DD MM YYYY 01 01 1904 01 01 1904 Time a before plot b after plot gt GlucoBox vi Q configuration Q display in progress transmission 9 error STOP User Config Display Debug 189 Dea A Glucose level RAS 01 00 00 07 00 00 15 26 38 17 02 2006 18 02 2006 18 02 2006 18 02 2006 Time c after zooming Figure 5 5 graphic display steps 42 93 GlucoBox System LPM EPFL rr GlucoBox vi Figure 5 6 d
54. ime s 18 10 572 Figure 7 3 power consumption over a period of 10 minutes The average current consumption is given by 3 x 6 x 70 2 x 5 x 40 572 5 600 mean current 8 mA Hence battery lifetime is given by 1500 battery lifetime 187 5 gt 7 days 52 93 GlucoBox System LPM EPFL 8 8 1 CONCLUSION FUTURE WORK As we have seen in the previous chapter both hardware and software concepts of the GlucoBox System have been validated Nevertheless some important aspects must be reviewed to provide better reliability These points are in order of priority RF transmission sources of malfunction must be identified and corresponding measures must be taken This part is crucial as without it the concept is no interest In case of failure it is highly recommendable to move to another transceiver The main reason is that new IC on the market require less critical layout Moreover new functionalities are directly implemented in the IC itself enabling higher communication reliability PC software some unexpected errors have occurred during utilization and have to be rapidly identified Moreover it desirable to have two versions for doctor and patient Debugging of embedded software and optimize code for better performance Integration the first application GlucoBox System was to operate with a bio sensor In this context it is desirable to test the concept with real bio senso
55. ing a button a reading is re quested from the bio sensor and the glucose rate is displayed within 5 s If glucose level is out of normal range an alarm resounds The device can be scheduled to automatically request a reading without patient s interven tion Measurements are stored in the device itself Later on the patient can transfer all measurements to a PC via USB with the help of a user friendly computer program Data can then be exported for further analysis by a healthcare professional Results Currently all functional tasks are achieved according to project requirements However only one main requirement has not been reached RF range is less than the ex pected 3 m In spite of poor RF performance the concept of the GlucoBox System has been validated GucoBox vi configuration LD transmission display in progress Qaro Display Debug 205 222 16 16 00 17 02 2008 152638 1802 2006 010000 070000 18022006 18022006 Time GlucoBox Control Device amp Software Main characteristics Dimensions 23 x 62 x 103 mm Weight 115 g Power autonomy 7 days Storage capacity 85 000 measurements Conclusion and future work The Glu coBox System performance was evaluated and compared to existing products it fulfills many characteristics which make it a good founda tion for the commercial product Finally we would like to point that for the next step the RF part which is essen
56. ion graphic Storage raw format a Export format CSV Monitor control Data download time max 2 min Data erase yes Configuration yes This file format is often used to exchange data between dis parate applications Table 2 2 monitor requirements IrDA ADVANTAGES e Computer software allowing data transfer via USB exists e Comfortable display screen 160 x 160 pixels 16 level grayscale backlight and a touch screen interface e Attractive product for a demonstrator bench especially with a flexible circuit in the watch bracelet DISADVANTAGES e Interface limitations Slave USB interface communication must be established by a master device This requires subsequent coding and only few devices can be found on a market IrDA interface in addition to RF link another wireless module is needed which complicates the integration e Multi target development necessary solution requires software development for three different targets Wrist PDA RF interface device and computer e Dependency of a commercial product the price availability and development tools of the system depend on the evolution of this product It can be a solution for a demonstrator bench but not for future development IrDA Infrared Data Association wireless optical communication 10NB On February 2006 Fossil seems to have discontinued this watch 9 93 GlucoBox System LPM EPFL Ta e _ _ eteE GG
57. k on My Com puter and choose Properties Automatic Updates Remote General Computer Name Advanced r Device Manager The Device Manager lists all the hardware devices installed on your computer Use the Device Managerto change the properties of any device Drivers EX Driver Signing lets you make sure that installed drivers are compatible with Windows Windows Update lets you set up how Windows connects to Windows Update for drivers Hardware Profiles a Hardware profiles provide a way for you to set up and store different hardware configurations b Choose Hardware tab and click on Device Manager 22 8 Monitors Network adapters 8 PCMCIA adapters El Ports amp LPT 7 ECP Printer Port LPT1 27 USB Serial Port COM5 i 9 Processors SCSI and RAID controllers Sound video and game controllers System devices Universal Serial Bus controllers E gt Under Ports COM amp LPT there must be USB Serial Port COMx where x denotes the communication port to be used in GlucoBox Software 70 B 7 4 INSTALLING GLUCOBOX SOFTWARE gt Insert the installation CD in your CD ROM drive Execute setup exe found in GlucoBox Software directory 22 G GlucoBox Software DES File Edit View Favorites Tools gt Welcome to the GlucoBox Installation Wizard It is strongly recom
58. kes medication if needed For measurement a small drop of blood is taken generally at the fingertip with a reactive strip and the latter is inserted into the device shown in figure 2 1 a After five seconds the glucose rate value is displayed on the screen in a large number format Date and time are also indicated Then the patient must write the value on a notepad for further analysis The system including the device the strips and the notepad is usually kept in a little bag Its size is about 180 x 100 x 30 mm and weighs 60 g A compact version exists without the bag 115 x 56 x 30 mm Moreover the device has the capability to store up to five hundreds measurements The patient or the doctor can transfer data to a computer for analysis via an infrared connection to an adapter connected to the computer A software is available for the patient to help him to manage and analyze his measurements The whole system is an effective manner to regulate glucose rate Indeed the monitoring device is very easy to use and fits appropriately the needs However it is not a continu ous monitoring system and blood sample is required which may be uncomfortable for some persons especially children 2 1 2 CcGMS 2 In certain cases the doctor often prescribes CGMS2 manufactured by Medtronic Min iMed to collect accurate and continuous glucose levels Data are analyzed to diagnostic hid den blood sugar patterns such as hypoglycemia and to
59. lly select the USB port or the AC adapter as the power source for the system In the USB configuration the host can select from two preset charge rates of 100 mA and 500 mA In the AC adapter configuration an external resistor sets the magnitude of the charge current This IC has been chosen for its functionalities compactness and simplicity of implementation When using the bq24022 a suitable external AC adapter is a 6 V with a minimum of 1 A output In our case current drained from USB port has been limited to 100 mA 4 5 EMBEDDED SOFTWARE The software embedded on the GlucoBox has been programmed in C language and compiled with a dsPIC version of gcc C30 see appendix C 1 The MPLAB IDE v7 22 has been used for its development Source code files are available on installation CD see appendix H 4 5 1 MAIN The main function has two parts they are shown in figure 4 8 1 initialization calls different initialization functions 2 infinite loop calls four tasks sequentially The user storage and display return a value corresponding to its state active or inactive This information is used by the energy task to manage power The current implementation allows a reboot intentional or not without much problem This is achieved by saving critical parameters alarm scheduling next storage address on the non volatile flash memory Hence even if the MCU is reseted these parameters can be loaded at any time If an unexpected problem
60. mended that you exit all Windows programs before running this setup program Click Cancel to quit the setup program then close any programs you have running Click Next to continue the installation WARNING This program is protected by copyright law and international treaties Unauthorized reproduction or distribution of this program or any portion of it may result in severe civil and criminal penalties and will be prosecuted to the maximum extent possible under law Cancel 71 15 GlucoBox Setup Sat Updating System The features you selected are currently being installed p Click on Finish to end installation process 5 GlucoBox Setup GlucoBox has been successfully installed Click the Finish button to exit this installation Cancel 72 C TECHNICAL USER MANUAL C 1 SOFTWARE USED e MPLAB v 7 22 e C30 C compiler for dsPIC v 1 33 e LabView for Windows v 7 0 e Matlab v 7 1 e Catia v VR 11 e DXP 2004 build 8 0 4 1272 C 2 ACCESSING PROGRAMMING INTERFACE 73 74 d contents of backside T5 D COST CALCULATION COMPONENTS COST CHF TOTAL display LCD module backlight IC power supply battery charger IC voltage regulator level translator bridge rectifier antenna RF IC crystal 16 MHz buttons 30 enclosure 14 super capacitor crystal 32 768 kHz RT
61. n table 2 2 7 93 GlucoBox System LPM EPFL a ss MONITOR REQUIREMENTS User interface Interface easy to use Autonomy min 7 days Acquisition time max 5s External design Look attractive Size max 120 x 80 x 30 mm Weight max 200 g Display Content value date time trend Value dimensions min 20 x 10 mm Units format mmol l Precision one decimal place Retro lighting yes Measurements Automatic yes On request yes Storage capacity min 3 months measurement at 10 minutes interval Primary format audible Mute mode yes Glucose rate thresholds configurable Computer link Intermediate device none Wireless communication with bio sensor Range min 3m RF compatibility medical specifications Table 2 1 monitor requirements 2 5 SUGGESTED SOLUTIONS This section presents some interesting solutions with their advantages and disadvantages 2 5 1 Wrist PDA 3 The LPM was interested in having an attractive product such as a watch The Wrist PDAS proposed is based on Palm OS the software development is done directly on a Palm or with an emulator An RF interface must be developed using available interface on Wrist PDA USB or PDA Personal Digital Assistant TOS Operating System 5USB Universal Serial Bus 8 93 GlucoBox System LPM EPFL ixxuc aa ama u COMPUTER INTERFACE REQUIREMENTS User interface Interface easy to use Presentation graphics with buttons Data management Presentat
62. nding values of year month day date hour minute and second 4 2 4 DISPLAY The measurement must be displayed on a screen to inform the patient of his glucose level A large dot matrix LCD module including driver has been chosen to allow further en hancements glucose level trend on a graphic on GlucoBox Its characteristics are shown in table 4 4 For integration of the backlight the IC named SP4422A from SIPEX has been withdrawn from its based module PSEL 22 10 provided by Electronic Assembly and placed directly on the hardware design For more details refer to appendix E 4 DISPLAY Display reference W128A 6X9HEW 11 from Electronic Assembly Driver reference S6B1713 12 from Samsung Electonics Interface SPI or parallel Resolution 128 x 64 pixels Display size 52 x 33 5 mm Voltage 2 4 to 3 6 V Sleep current 100 LA Table 4 4 graphical LCD module characteristics DISPLAYING A PICTURE The main drawback of graphical display is that displaying a text is not easy As a matter of fact the characters are represented by pictures and each bit of the picture must be correctly located on the screen The data displayed are transfered from the MCU to the DDRAM of the display driver via the SPI interface The data are mapped in a 65 row by 132 column array addressable via page and column selection for more details refer to the datasheet To load picture into the DDRAM see appendix F 5LCD Liquid Cristal Display l6
63. nse de 45 minutes environ 25 minutes de pr sentation et d monstration plus 20 minutes de r ponses aux questions aura lieu dans la p riode du 13 au 20 mars 2006 Le Professeur responsable L assistant responsable Lausanne le 8 novembre 2005 LPM IPR STI Abstract of Master project February 24 2006 GlucoBox System Sadasing Kowlessur Damien Perritaz Micro engineering Professor Prof Peter Ryser Assistants Eric Meurville L andre Bolomey Introduction A bio sensor is currently un der development at the LPM The goal is to measure glucose level in blood of diabetic pa tients who need continuous glucose level mon itoring The objective of this project is to build a control device capable to communicate with the sensor and to transfer data to a PC A request can be triggered by user or sched uled at a chosen frequency The global con cept is a system including the control device itself and a PC software GlucoBox System is depicted in figure below The project is divided into four main steps research of solutions design and manufactur ing software development and final tests control device Work The starting point was to study ex isting solutions and to evaluate patients needs After having defined the project requirements the selected solution was to build a custom made system rather than using an existing host device Our work lead to user friendly control de vice by press
64. ntrol device If the latter is in idle mode external devices are put in energy saving mode and the MCU enters sleep mode Any interrupt can then wake up the MCU Only then the other peripherals are waked up if necessary This procedure is shown in figure 4 12 32 93 GlucoBox System LPM EPFL PIISGRRSSTLOONIOOIO A M 7 H Interrupt UART Y Store command and data Inactive Execute command Active Figure 4 9 user task 33 93 GlucoBox System LPM EPFL Interrupt Storage task extern RTC alarm Check acquistion period lt New storage Inactive YES Acquire time Period over from RTC Y Acquire value from sensor via RF NO No storage New storage Acquisition Store data on FLASH Y Check value YES Out of range Activate alarm NO Figure 4 10 storage task 34 93 GlucoBox System LPM EPFL Interrupt Interrupt Display task extern extern TIMER 2 s GREEN but RED but Start timer for 2 ED t seconds s utton i s still ON Out of interrupt Timer started Sound alarm off 6 Y Acquire time from RTC y Acquire value from Inactive senso
65. nttp www sipex com ITDDRAM Display Data Random Access Memory 24 93 GlucoBox System LPM EPFL LII 4 2 5 ALARM An audio transducer has been chosen for audible alarm Its electrical consumption is lower than a buzzer Moreover by using the MCU PWM module it is possible to modulate the signal volume and frequency ALARM Reference PKM13EPY 4000 A0 13 from Murata Sound pressure level min 70 dB Voltage max 30 Vp p Table 4 5 piezo ceramic alarm characteristics 4 3 WIRELESS COMMUNICATION The wireless link between the GlucoBox and the sensor is done with a RF IC Many IC s are available on the market but only some of them can operate in the 433 MHZ ISM 14 Industrial Scientific and Medical band Moreover IC for medical applications such as active implants should comply with special regulations and manufacturers are less willing to face lawsuit in case of device incompatibility or failure An implementation of a RF chip has been done during a summer semester project citeremy at LPM laboratory At the end of this project an IC has been chosen by taking into account different important parameters refer to the project report for more details and a PCB has been realized Although it does not fully comply to the medical implant regulations the IC has been chosen as its operating frequency is close to that required for medical implant Indeed for a demonstrator an implant has not
66. o cure for diabetes In order to treat diabetes the patient s instan taneous glucose level must be known The most reliable measurement is actually done by analyzing the blood The patient takes a blood sample and with the help of a glucometer he can read its instantaneous measurement Nowadays portable glucometer helps patients to have a merely normal life style If glucose level is too high hyperglycemia the goal of treatment is to lower glucose level through medication in the form of insulin On the other hand if glucose level is too low hypoglycemia patient needs to eat sugar to restore glucose level The International Diabetes Federation estimates that at least 194 million people in the world have diabetes 1 2 SCOPE One of the benefits of using the bio sensor made by the LPM is to avoid patient from taking a blood sample Indeed the final form of the sensor is a miniature implant which needs only minor surgery intervention At this stage of the development of the sensor a prototype of the sensor exists Moreover a built in RF module will allow measurements to be sent to remote device for further analysis The objective of this project is to build a control device capable of communicating with the sensor in the frame of a demonstrator bench Results and the end of this project may be considered as important guidelines for a commercialized version of the control device ILPM Laboratoire de Production Microtechnique http
67. oBox System REGULATOR SCHDOC 15 YOSNIS FUNIVBAdNIL 84 G8 X6 MCLR CONI vec cs cs SCLK 10 10 DATAIXO ARRA S S n DATAIXO dsPIC30F40 11 QFN DATACLK INTX CN DATACIK 22855 2 8 8838 Surga 7 9 LD FEET 545 ID Z ZES 8292 RSSI gt RSSI PER 7 PIN F PERIN 88 55 8 3 3 SU 6 EB osc2CLKORCIS Z ga E 2 gt OSCI CLKIN 39 3 2 8 gt VSS ao B PWM3L VSS a z Sa 9 28 PGC MUC UIRXSDIL SDA RF2 PWM2H H vpp ZE UZTX CNISRES gt Z vpp U2RXICNI7 RF4 9 PWM2L vec 27 CTXIRFI 21 ANSRBS CRXURA PWMIH el 4 UN 26 1 AN7 RB7 amp gt e lt SI l 4 51 ANGOCFA RB6 vss LO PWMI 5 25 1 ANSIQEBACS CN7 RBS 33 P lt ane Q lt ux 231 6 5 von Lir EPNM 5042255 5 8 4 5 2 2 100nF 2 VDD veccH H von GND zz 3 6 ena voma GNDA S S3 8 22 E 22 ZZ PWM3HRES 2 Cs z z 8 EB 2 ZZ Z PWM3UREA 1
68. on glucometers and patients needs e Mr Michel Tille Electronitel SA was our contact for MICREL parts e Mr Julien Chassot LPM EPFL for his encouragement us throughout the project e Mr Valentin Longchamp and Samuel Progin EPFL our classmates for their con structive remarks on our report 55 LIST OF FIGURES 1 1 2 1 2 2 2 3 3 1 3 2 3 3 3 4 4 1 4 2 4 3 4 4 4 5 4 6 4 7 4 8 4 9 4 10 4 11 4 12 5 1 5 2 5 3 5 4 5 5 5 6 6 1 6 2 6 3 6 4 7 1 7 2 7 3 general concept of the control device 2 commonly used monitor devices found on the Swiss market 5 custom made concept Sx software development Hx hardware development 12 concept based on an existing host Sx software development Hx hardware development 12 GlucoBox dimensions in mm 14 view of connectors of GlucoBox 15 details of programming connector 16 graphical interface 17 hardware architecture of GlucoBox Control Device 20 electrical interface of MICRF506 26 description of protocol for MICRF506 27 structure of the frame values indicate size in bytes 28 only few steps are required to use RF protocol 29 examples of use of RF protocol
69. ontents 7 1 Test conditions s lt sas sos s w x Sw dus RR X Rx WU Q 49 422 Results ru remet ale 2 49 RE leali See ect ss Sa RL 50 7 2 2 Gathering data and display in PC software 50 7 2 3 Power consumption 51 As we have seen before the electrical part of our concept is predominant Therefore no mechanical tests have been made Electrical test is the first prerequisite for validating our concept For this purpose each part of the architecture was tested separately starting with the power management Once all parts had been tested individually the whole system has been subjected to different tests 7 1 TEST CONDITIONS To validate our concept a bio sensor is required Unfortunately at the test phase of the project the bio sensor was not available In fact the demonstrator bench module was ready but no measurement was feasible For this reason the base module for the bio sensor has been modified to integrate a temperature sensor for schematics refer to appendix E 8 to E 11 Furthermore the RF part of the module had not yet been validated as mentioned before no characterization was made at that time 25 In this context temperature values are fetched in place of glucose levels The temperature sensor has been programmed so that its response is similar to expected bio sensor 1 s for making a measurement and value sent is coded on 4 bytes Moreo
70. phic for a day week or month Other information include an average on a day week or month basis and score in percent of the time in which the patient was in over or under the normal range 2 3 2 DOCTOR INTERFACE The doctor will certainly follow many patients a multi patient management should be set up His interface should be able to communicate with different devices and store data in adequate folder To avoid errors from patient manipulation erasing data stored in the monitoring device must only be made by the doctor Thus data will not be lost between two medical ap pointments time between two appointments may vary from 1 to 6 month depending on the severeness of the diabetes More sophisticated data analysis tools must be available for healthcare professionals For example the doctor should be able to superpose weekly graphics or make statistical analysis 2 4 PROJECT REQUIREMENTS The systems presented in sections 2 1 1 and 2 1 2 are complementary but no single system exist Such device associated with the sensor developed in the LPM would have the following characteristics e continuous glucose monitoring without patient intervention e data stored in the device itself for a long period of time e display of measurement on request for auto regulation The monitor requirements based on section 2 2 are shown on table 2 1 The computer user interface must have main functionalities presented on section 2 3 They are shown o
71. r as quickly as possible In this part the implementation of the RF protocol will also be validated on the bio sensor Update hardware and software implementation in the MCU according to manufac turer s up to date information at this time not all parameters have been defined Measure more precisely power consumed by each part and optimize the system s power management Whole system add and improve functionalities for ease of use Review PCB design for greater performance and to accommodate custom identification used by FTDI IC an external EEPROM is requires to store vendor information 8 2 PROJECT CONCLUSION The initial goal of the project was to develop a simple device to communicate with a bio sensor for a demonstrator bench But our motivation grew up when we noted that our project can in a longer term help people suffering from diabetes GlucoBox System can be considered as a concept for a future commercial product in the medical field This project is very ambitious Indeed our role was to build the foundation for the com mercial product In spite of having only few guidelines at the beginning of our project we 53 93 GlucoBox System LPM EPFL _ _____ _ ________ _ _G5 have been able to tackle a typical engineer problem from the beginning to the end Finally we ended up with a functional concept in a relatively short period of time We hope that our project will be carried on an
72. r via RF A Y Display value and Toggle alarm time on LCD enable disable Active Active Figure 4 11 display task Energy task inactive since 500 ms NO Loop to user task YES Devices in sleep mode Y MCU in sleep mode Wake form interrupt Loop to user task Figure 4 12 energy task 35 93 GlucoBox System LPM EPFL 5 SOFTWARE Contents 5 1 Programming environment Labview 36 5 2 Functionalities se s w 2 9 we EU 4 wQ W Q 36 5 201 Cong tab aes None 36 52 2 User tabs sajer nae 4 A Re te X 37 5 2 3 Display tab i 14446444 si eet ieee eb ea 38 p24 Debug tabs w pre esra Pi Won ran 93 e Mo eG pes 38 The GlucoBox software running on the computer is a graphical user interface giving the possibility to manage data acquisition storage graphic display and export and parameters from the Glucobox The goal of this software is to quickly show the capability of the control device 5 1 PROGRAMMING ENVIRONMENT LABVIEW Labview has been chosen as it allows rapid development of complex program It contains a lot of functions for data acquisition file management and other useful features Indeed Labview has built in serial functions which allow easy communication with the serial device The final application has an attractive visual interface 5
73. repair the device yourself 61 B GLucoBox USER MANUAL Do not apply excessive pres sure on the device Do not expose to chemicals such as benzene and thinners My Do not touch the charger with wet hands B 2 COMPONENTS 5 52 GlucoBox Control Device USB able ale Aces malo mini B N AC Adapter User Manual Installation CD 62 B 3 BATTERY CHARGER SAFETY CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN The uninsulated parts inside the charger could cause electric shock For your safety do not open the case of the charger Read this User Manual to prevent any problems that may occur while using the charger gt gt P Warning Use the charger away from water sources to avoid fire or electric shock Caution To avoid electric shock use the charger only with a 220V power outlet Make sure that the charger s plug is inserted all the way into the outlet 63 B 4 CHARGING THE BATTERY p With AC adapter e Plug the charger into a wall outlet e Connect DC jack of charger to DC outlet on device LED will lights up e When charge is complete battery logo will be full gt With USB port e Plug the USB cable into the USB port of your PC e Connect mini USB end of cable to the device and LED lights up e Charging starts automatically and continues even when using software B 5 LOCATION OF CONTRO
74. rest of the memory 15 sectors can handle up to 85 000 measure ments including time stamp in the current implementation Modifying data can be done by two ways e Write data It is the more usual way to modify data The PW instruction provides a convenient way of modifying data and simply requires the start address and the new data in the instruction sequence This instruction takes typically 11 ms e Program data The PPH instruction provides a fast typically 1 2 ms way of modifying data provided that it only involves resetting bits to 0 that had previously been set to 1 after a PE instruction for example In current implementation a total erasing with PE instructions is done before that the measurements are stored This erasing ensures that no overwriting occurs and that all bits are set to 1 It provides the use of PP for measurements storage which is faster than PW EEPROM Electrically Erasable Read Only Memory 10 Page Write H pp Page Program PE Page Erase 21 93 GlucoBox System LPM EPFL _kn1RqkR0h1k1k1_ _mT__mm_el_e r However PW is used for the special parameters first sector because these data are contin uously overwritten without PE instruction being done between two PW instructions It is important to note that if memory is full all subsequent storage of readings is ignored In this case patient is informed by an icon on the display 4 2 2 USB TRANSCEIVER A
75. s activated during process Other reactions may occur after a value has been acquired the general trend T or is shown then according to glucose threshold alarm that has been previously set an audible alarm may resound the bell icon is activated by default One can notice that this process can be scheduled to occur at regular time interval in this case no information is displayed except in case of an alarm When the USB cable is plugged into the device the latter is automatically recognized provided that appropriate drivers have been installed prior to connection User can then run host application to start communicate with the control unit For more information about functions available in software go to next section The built in battery of GlucoBox can easily be charged by two methods energy can be taken from either an AC adapter specifications are given in appendix A supplied with GlucoBox or from the USB port The first method is quicker The device is equipped with a buzzer that can emit a beep on programmed alarms The sound level can be set or deactivated using button sound mode can be toggled by holding button for 2 s 14 93 GlucoBox System LPM EPFL TO one 3 1 3 CONNECTIVITY COMMON CONNECTIONS On the side of the device there are two connection ports a mini female USB port for com munication with a PC and a female DC plug There is also a reset button accessible with the help of a pin and a char
76. s are required to immediately use the RF communication The trade off is that some part can only be set at firmware level for more details refer to appendix G Figure 4 5 shows how to proceed in main program Initialization Set local parameters Set RF mode Transmit packet Receive packet L Toggle mode 4 Figure 4 5 only few steps are required to use RF protocol A typical scheme on application is given in figure 4 6 In this example figure 4 6 a represents the master GlucoBox while figure 4 6 b corresponds to the slave sensor Using different power states it is possible to implement a low energy consuming application For example RF IC can be automatically put in standby mode after a transmission of a reception For more information on how to use these routines along with code examples see appendix G 26CRC Cyclic Redundancy Check 27 CCITT Comit Consultatif International T l phonique et T l graphique now known as the International Telecommunication Union 29 93 GlucoBox System LPM EPFL initiate communication initiate communication Send packet Data received Extractdata Waitfor response no signal signal present Receive packet Re send packet Send packet Rety Take counter counter measurement a master state machine b slave state machine counter 0 Figure 4 6 examples of use of RF protocol 4 4 POWER SUPPLY The power scheme fi
77. s of equipment Receiver is programmed to respond to only a specific class ID and to one sender address at a time Recipient s Address This value is verified by receiver to check to whom the packet is intended In this case of address match with its own address receiver will undertake action 28 93 GlucoBox System LPM EPFL Ta ssswOs s2 eee e___ CRC Value Integrity of packet must be verified to ensure that data it contains are correct A CRC computation is a common way to validate data integrity Implementation used is based on the CCITT algorithm The 16 bit version is used 19 More information can be found on the Internet a good start is 20 Frame type The final payload extracted is called Payload Level 2 It includes a field that designates the type of the frame It allows custom commands to be simply implemented here and extra data can be put in the rest of the payload Payload Level 3 In our case the values given are sufficient to realize required tasks in a Master Slave configuration the master being the GlucoBox and the slave is the remote sensor The size of each part can be easily modified to fit other applications Moreover the frame structure provides a flexible framework to implement more complex networks multi master routing broadcasting etc 4 3 3 SOFTWARE IMPLEMENTATION The main idea of the software implementation is to make usage simple to programmer Indeed only few routine
78. s the chosen MCU does not have a USB module an external transceiver in needed to communicate with a PC For this purpose specialized IC are available on the market the most common of them is the FT232B 7 from FTDI The main advantages of using this IC is its maturity and the complete software support from the manufacturer The connection on the host PC can be implemented in two ways as a serial communication port or a normal USB port both drivers are available for different OS The first method is simpler for the software development on the host PC Moreover a high transfer rate is not necessary for our application The characteristics of the FT232B are summarized in table 4 2 Reference FT232BQ Interface UART amp USB IO voltage 3 0 to 3 6 V Suspend current 200 LA Package QFN32 Dimensions 5 x 5 mm Table 4 2 USB transceiver characteristics HARDWARE No particular components are required to use the FT232B refer to appendix E 6 except that care must be taken regarding to the precision of the crystal see datasheet for more details An interesting feature of the FT232B is that it can be powered from the USB cable thus the IC operates only a USB connection is present This simplify power saving scheme implementation SOFTWARE As mentioned before the FT232B is used a serial communication port on the host PC Hence the FT232B is transparent to the communication between MCU and host PC Indeed for the PC the MCU is a simpl
79. sited Febuary 2006 KOKAM Internet website http www kokam com page visited Febuary 2006 MAXIM MAXSSS3 product information http www maxim ic com quick view2 cfm qv pk 2410 page visited Febuary 2006 TEXAS INSTRUMENTS bq24022 product information http focus ti com docs prod folders print bq24022 html page visited Febuary 2006 Tim Williams The Circuit Designer s Companion Elsevier 2nd edition 2005 R my Demierre Transceiver RF pour bio capteur Semester project LPM EPFL June 2005 59 A DEVICE SPECIFICATIONS General Dimensions WxHxD Weight Case Display type Electrical Built in rechargeable battery capacity Charger voltage Charger current Charger polarity USB current consumption charge mode Charge time from AC adapter Charge time from USB max 100 mA PC requirements Pentium 200 MHz or greater 256 Mb or RAM Windows XP VGA 800x600 or above 100 Mb of available hard disk space CD ROM drive 2x speed or greater USB 2 0 port 1 1 not supported 62 x 23 x 103 mm 115 g black ABS plastic LCD 128 x 64 pixels with backlight 1500 mAh at 3 7 V max 6 Volts min 800 mA positive or negative centered DC jack max 100 mA max 3 hours max 18 hours 60 SAFETY INSTRUCTIONS Do not expose to extreme temperatures above 85 C or below 5 C Do not expose to moisture Do not let any foreign matter spill into the device Do not try to disassemble and
80. t is obvious that all necessary components should be known For this purpose each device has been tested on prototype boards to evaluate them Then all values of each component were assigned The first step when designing a PCB is to know which technology will be used In our case standard rigid epoxy board 0 8mm thick for two layers has been chosen The main reasons for this choice is that the PCB can be realized quickly at ACI workshop of the EPFL lhttp sti ateliers epfl ch page8438 html 44 93 GlucoBox System LPM EPFL Ta sy3 a s 56 F iuwmrsimssT w as rsv and a two layer design can be easily analyzed for errors However a two layer design is not optimal in a mixed analog digital configuration Thus special precautions must be taken 24 Moreover general fabrication rules must be respected they are given by workshop Main constraints associated with the GlucoBox architecture are listed below e RF part as far as possible from digital part e RF components as close as possible to MICRF506 e Largest ground plane on the bottom layer except below the antenna e Two separate power planes on top layer e No parts or signal below RTC crystal e Tracks as short as possible for analog signals e LCD connector on the bottom layer e Include fixation holes e Two PCB main board and daughter board connected through a multi way cable It should be noted that all components are all SMD type except for buzzer
81. t purposes the room temperature was sampled by GlucoBox automatic sampling period of 2 minutes for a period of 24 hours At the end of this test data have been transfered to a PC using the GlucoBox software A plot of this result is shown in figure 7 2 Figure 7 1 GlucoBox displaying a reading 1 1 scale Mr Jean Fran ois Zurcher from the LEMA laboratory at EPFL 50 93 GlucoBox System LPM EPFL GlucoBox vi Q configuration Q display in progress Q transmission error STOP User Config Display Debug Current z Ha Glucose level RAS 01 00 00 07 00 00 15 26 38 17 02 2006 18 02 2006 18 02 2006 18 02 2006 Time Figure 7 2 temperature plot using GlucoBox software 7 2 3 POWER CONSUMPTION According to project requirements at least a week of autonomy is need Yet a greater au tonomy is achieved by current design as shown by equations below Case of figure values of current consumption are those measured on actual design e automatic measurement each 10 minutes e duration of a request 6 s with no display worst case duration of display after a manual request 5 s 2 manual requests in each interval of 10 minutes battery fully charged current level during a request 70 mA current consuption during display 40mA 51 93 GlucoBox System LPM EPFL e current consumption of 5 mA during idle mode Current mA A 70 40 gt T
82. ta size timeStamp size measurement size number of data acquisition period x acquisition frequency with timeStamp size 7 bytes measurement size 4 bytes 3 months 90 days acquisition frequency 6 per hour 144 per day gt memory size 7 4 x 90 x 144 142560 bytes acquisition period 81 byte for each hour minute second day date month year 20 93 GlucoBox System LPM EPFL PIEIRRSUULOUDIODOO r The space required cannot fit into the MCU user memory type is usually EEPROM Hence an external memory with sufficient capacity is required A serial flash memory has been chosen as it requires few IO lines and it has a tiny package form It fits all the re quirements and standard models available have large capacities allowing longer acquisition periods The characteristics of the IC used are listed in table 4 1 NON VOLATILE MEMORY Reference M45PE80VMP 6 from ST Type Flash Memory size 1 Mbyte 8 Mbits Interface SPI Voltage 2 7 to 3 6 V Standby current 50 uA Packaging VDFPN8 Dimensions 6 x 5 mm Table 4 1 flash memory characteristics HARDWARE Electrical connections required is quite simple as shown in appendix E 3 SOFTWARE The memory is organized in 16 sectors each containing 256 pages which are 256 bytes wide In current use the first sector is reserved for GlucoBox special parameters These values are loaded after a reset The
83. ted Febuary 2006 ELECTONIC ASSEMBLY W128A 6X9HEW product information http www lcd module de eng pdf grafik w128 6xx pdf page visited Febuary 2006 SAMSUNG ELECTRONICS 56B1713 product information http www 1lcd module de eng pdf zubehoer s6b1713 pdf page visited Febuary 2006 MURATA PKM13EPY 4000 A0 product information http www murata com catalog p37e pdf page visited Febuary 2006 98 14 15 16 17 19 20 2 22 23 24 25 International Telecommunication Union ISM bands defined in FAQ http www itu int ITU R terrestrial fag index html g013 page visited Febuary 2006 MICREL MICRF506 product information http www micrel com page do page RF506 RW micr1 page visited Febuary 2006 Wikipedia Manchester code http en wikipedia org wiki Manchester encoding page visited Febuary 2006 PHYCOMP CAN 4311 121 200431B Multilayer ceramic 433 MHz 50 Ohms http en wikipedia org wiki Manchester encoding official web site is currently available but more information can be obtained from local distributor Farnell MAXIM MAX3001E product information http www maxim ic com quick view2 cfm qv pk 3672 page visited Febuary 2006 Scott Dattalo home page PIC Software section http www dattalo com technical software pic crc 1021 asm page visited Febuary 2006 Ross Williams A Painless Guide to CRC Error Detection Algorithms http www ross net crc crcpaper html page vi
84. th a time stamp e a USB to UART transceiver to allow communication between the MCU and a PC via USB IMCU Main Control Unit in our case it is a micro controller special device that is generally dedicated to a special task for example a non volatile memory Integrated Circuit Input Output 5 special dedicated part of the MCU which accomplishes a special task for example the UART module SPI Serial Peripheral Interface a trademark of Motorola Inc UART Universal Asynchronous Receiver Transmitter 19 93 GlucoBox System LPM EPEL In addition to peripherals power supply circuits must chosen to meet power requirements of all components Finally the architecture is illustrated in figure 4 1 Each component is discussed in the next paragraphs M N buttons Sound alarm Power managment MCU UART USB USB to UART dsPIC30F401 1 transceiver SPI RF transceiver NUN Non volatile Display management memory Figure 4 1 hardware architecture of GlucoBox Control Device M N J 4 2 EMBEDDED PERIPHERALS In this section the characteristics the hardware and software integration of the specific IC are explained 4 2 1 NON VOLATILE MEMORY The data must be stored in a non volatile memory to avoid loosing them in case of power loss The size of this memory must be at least 150 kbytes according to following equations memory size data size x number of data da
85. ther important point is to have a large display with clearly visible values Indeed one of the complication of diabetes is angiopathy resulting to a lower vision It is also important to be able to see value during the night so a retro lighting is needed Moreover contrast must be sufficient so that readings can also be made under excessive illumination example in sunlight There are different units for glucose rate In Switzerland mmol l is used in current systems and values represented in these units are meaningful to diabetics The measurement range in mmol l is from 0 to 30 One decimal precision is required for values under 12 Patients are accustomed to current systems in which date and time are also displayed with measurement A trend indication could help the patient to anticipate his medication 2 2 4 MEASUREMENTS Automatic measurements and storage guarantee a regular data acquisition for further analysis A measurement every ten to fifteen minutes seems to be sufficient but a lower frequency can fail to show rapid evolution The patient can also request his glucose rate up to date for his auto regulation However the number of acquisition per day requested by the patient could be limited to avoid a paranoia behavior 2 2 5 ALARM The normal glucose rate is between 4 and 8 mmol l If the rate is out of this range it could be dangerous An alarm can limit the problem in these situations The glucose rates given above are g
86. tial in our concept has to be improved CONTENTS Abstract ii 1 Introduction 1 What 1s diab tes xoxo osse Pew Un i o a S E 1 122 SCOPE un dee RNA EOS ISTE RU S IAS pus RON E HOW 1 1 3 Project overview 2 1 4 Project management 2 2 Basic concepts 3 2 1 State of the art 4 2 2 Monitor needs ss i ada Re U amuk x S 5 2 3 Computer interface needs 7 2 4 Project requirements 7 2 5 Suggested solutions 8 3 GlucoBox System 13 3 1 Control device Rev we eee Ho dau 13 3 2 Computer Interface U dus ses Sala e UR E das 16 4 Control device 18 4 1 Architecture s sz sz s w k wn wa esl w Epe wa ele s ka 19 4 2 Embedded peripherals 20 4 3 Wireless communication 25 44 Power supply Pe e e ee e Q MUN S Gee 30 4 5 Embedded software 31 5 Software 36 5 1 Programming environment Labview 36 5 2 Functionalities 36 6 Hardware design 44 6 Mechanical es x ke apas Rosie Bati ao um
87. tion Data are simply 8 bits values EXAMPLE TIME UPDATE PROCEDURE All commands are implemented in the same way An example of the time update command is described below The figure 5 4 shows how this command is implemented in Labview 1 The user activates the update time button 2 Labview sends the corresponding command 1 byte with the date and time 7 bytes via the serial port 3 The GlucoBox MCU receives the command through its interruption routine The MCU interprets this command and excepts 7 more bytes data When all the bytes have been received it stores them in a buffer 37 93 GlucoBox System LPM EPFL 111_ _ _ e uee_eue_ _e 4 The MCU executes the corresponding part of user task reads the buffer converts date and time to RTC compatible format and write them to the RTC 5 2 3 DISPLAY TAB In this tab a graphic shows the glucose level evolutions The development of this XY display is relatively easy thanks to Labview built in plot modules Some tools are available for the user to manage the graphic zooming moving In current implementation when the display button is activated a export file is auto matically created This csv file example 23 02 06 csv containing the data in a adequate format can be directly opened in Excel for further analysis Displaying the graphic may take some time
88. trol device will be referred to as GlucoBox Control Device and the PC software as GlucoBox Software the two are part of GlucoBox System 11 93 GlucoBox System LPM EPFL RF AT transceiver Computer link IOC lt S1 Storage alarm N c Figure 2 2 custom made concept Sx software development Hx hardware development Display Computer Control RF AT Butt link a device link transceiver lt Storage alarm DX 51 5 S3 H1 Figure 2 3 concept based on an existing host Sx software development Hx hardware development 12 93 GlucoBox System LPM EPFL 3 GLUCOBOX SYSTEM Contents 3 1 Control device xo Rx m wo W S W d 13 3 1 1 External aspect ss sss 4 4 44 e ee Rd 13 3 1 2 Manipulations 14 3 1 3 Connectivity n amp Kb la amp YR W ges 15 3 2 Computer interface 16 3 2 1 Running the interface 16 3 2 2 Using the interface 16 3 1 CONTROL DEVICE As seen before the important characteristics of the GlucoBox are its simplicity of use and reliability of measurement Hence our design takes into account these points as we will see in details below But first we must note that GlucoBox will b
89. ver the bio sensor has been programmed with an defined address and it responses only to a special command 7 2 RESULTS Currently all functional tasks are achieved according to project requirements However one main requirement has not been reached RF range is less than expected 3 m as described below 49 93 GlucoBox System LPM EPFL Y 7 2 1 RF Based on the reference from MICREL does not always imply good RF performance Indeed other factors such as routing design proximity of disturbance sources quality of power sup ply and antenna have great influence on RF performance The PCB design have been made by following basic rules but no guarantee was to be expected as stated by a RF specialist The recommendation was to design the PCB and then to evaluate RF performance This approach is comprehensible as no simulation for such designs can be performed for lack of electrical models However this does not mean that RF performance cannot be improved Unfortunately RF improvements and specific tests such as power loss and error rate have not been done due to lack of time and current knowledge In spite of poor RF performance maximum range is 20 cm the concept of the GlucoBox System has been validated as depicted in the following sections 7 2 2 GATHERING DATA AND DISPLAY IN PC SOFTWARE Figure 7 1 shows GlucoBox at work displaying a requested temperature value alarms set are arbitrary temperatures For tes
90. yet been developed this prerequisite is not absolute At the end of this semester project only basic electrical tests were realized but no software implementation had been done The next step to this work is to implement the software necessary to use the RF chip Before entering the software part we must consider basic information of the RF chip 4 3 1 MICRF506 OVERVIEW The MICRF506 15 from MICREL is a true single chip frequency shift keying transceiver intended for use in half duplex bidirectional RF links It operates in the ISM frequency band of 410 450 MHz at a maximum data rate of 200 kbps The chip is programmed via a three wire serial interface Features include transmit power selection low energy modes and 859127 8PWM Power Width Modulation 19402 405 MHz frequency band ITU T Recommendation SA 1346 US FCC rules CFR47 Part 95 628 and Europe s ETSI Standard EN301839 2 PCB Printed Circuit Board lkbps kilo bits per second 226551 Received Signal Strength Indicator 25 93 GlucoBox System LPM EPFL PIOGGIA III N TS 7 EY The design of this transceiver is based on the reference design supplied by MICREL General configuration of the MICRF506 in our application is summarized below e 433 MHz operating frequency e VCO modulation at 38 462 kbps e Manchester encoding e RSSI enabled Manchester encoding 16 has been used as it does not add much overhead This type of coding

GlucoBox System

Contents

Download Pdf Manuals

Related Search

Related Contents