N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research                and Applications ...
N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research                 and Applications...
N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research                  and Application...
N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research                and Applications ...
N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research                          and App...
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  1. 1. N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.1440-1444Design And Development Of A Microcontroller Based System For The Measurement Of Blood Glucose N. Anju Latha1*, B. Rama Murthy1, U. Sunitha2, 1. Department of Instrumentation, Sri Krishnadevaraya University, Anantapur, A.P., INDIA 2. Department of Electronics, Sri Krishnadevaraya University, Anantapur, A.P., INDIAAbstract Diabetes Mellitus is a group of metabolic diabetes, so lifelong treatment is the only alternativediseases characterized by high blood sugar with continuous monitoring with diet control. Blood(glucose) levels which results from defects in glucose of a person has also been routinelyinsulin secretion. In the present study, a measured at medical checkups. There are differentmicrocontroller based system for the methods of in blood glucose measurement,measurement of blood glucose is designed and Amperometric method, Spectroscopic method,developed. It is based on the Amperometric Calorimetric method. In self measurement bloodmethod. A PIC 18F4520 microcontroller is used Glucose meters amperometric method is mainlyin the present study. LCD module is used to used [6]. Glucose measurement technique useddisplay measured values of blood glucose oxidation method. The whole operation isglucose.The MAX232 is a dual line very simple with enzymes oxidation, which transfersdriver/receiver, converts signals from an RS- electrons to electrodes.232 serial port to TTL compatible signals is There is evidence that the chorionicinterfaced with the microcontroller. Software is complications of diabetes are related to the durationdeveloped in C language using MPLAB IDE for and severity of hyperglycemia (diabetes control andthe Microchip Technology, due to the inherent complications Trial Research group 1993, UKlanguage flexibility, the extent of support and its prospective diabetes study group 1998). Howeverpotential for portability across a wide range of good diabetic control is very difficult to achieve inhardware. The instrument is tested and results many diabetic patients and frequent blood glucoseare found to be satisfactory. The instrument is testing is needed to detect hyper andhandheld, rugged, low cost, low energy hyperglycemia[7]. The most investigated technologyconsumption, wearable and cost effective for in vivo glucose monitoring is based oncompared to the other commercially available. implanted Amperometric enzyme electrodes [2] (Mastrototaro, 2000, sachedina and Pick up, 2003).Keywords: Blood glucose measurement,Amperometric method, PIC 18F4520 Tight control of blood glucose levelsmicrocontroller, RS232 level translator and achieved through frequent blood glucose monitoringMPLAB embedded workbench IDE for microchip. has been shown to be effective in reducting complicatins such as Retinopathy, Nephropathy andI. INTRODUCTION Neuropathy [3,4] The blood glucose is an important criterionto discriminate the health condition of patients in Principle:clinical field. Blood glucose of a patient is measured In the present paper, we measure the blood3-4 times per a day in constant timer interval. glucose based on Amperometic method. TheDiabetes is a disease where the body doesn‟t glucose sensor [5] is an electrochemical diagnosticproperly use or produce insulin [1]. Insulin is a strip which used glucose oxidase enzymes. Whenhormone produced in the human body which is need blood sample is applied, the enzyme becomesfor the conversion of sugar, starches and other food catalytically active and mediator compound transferinto energy. Without insulin the body would not be electrons to the electrode. The electrical signal isable to receive the amount of energy needed to then processed, amplified and converted into displayfunction, which is why diabetes is such a serious by microcontroller.disease. There are two types of diabetes Type I andType II. Type I diabetes is where an individual‟s Glucose Oxidasebody doesn‟t produce insulin. Type II diabetes is Gluconicwhere an individual body doesn‟t properly use Glucose + acid +insulin combined with a relative insulin shortage O2 + H2O H2O2within the body. Type II diabetes is the more GODcommon type with about 90% of people withdiabetes having this form. There is no cure for 1440 | P a g e
  2. 2. N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.1440-1444II ExperimentalA. Hardware Design The block diagram of the microcontrollerbased system for the measurement of blood glucoseis shown in fig 1. An Illustrative schematic diagramis shown in fig2. Liquid Crystal Display Glucose Test Glucose detection Personal Stripe circuit Computer PIC 18F4520 Micro Controller Filter circuit MAX 232 A/D conversionFig1: Block Diagram of Design and Development of Microcontroller based system for the measurement ofBlood Glucose. R1 R2 22K 1K R3 -5V LM358 VCC R4 1 100K +5V X2 1 2 2K 1 8 1 2 3 2 1 8 7 U1 MAX232 6 11 32 4 3 3 2 7 6 7 2 5 4 4 3 6 5 2 25 10 T2OUT 7 VDD VDD 5 -5V 4 5 3 RA0/AN0 RC4/TX 26 9 T2IN 8 3 4 RA0/AN1 RC4/RX R2OUT R2IN C7 8 5 RA0/AN2 R18 1 4 sensor 6 RA0/AN3 1K 2 1 1 9 7 RA0/TCLK 3 2 C+ 3 5 33 RA0/AN5 40 R19 100 4 3 11 C1- 4 C4 10uf 34 RB0/INT RB7/PGD 39 5 4 13 T1IN C2+ 5 35 RB1 RB6/PGC 38 6 5 14 R1IN C2- 2 36 RB2 RB5 19 7 6 12 T1OUT V+ 6 C6 37 RB3/PGM RD0/PSP0 20 8 7 R1OUT V- 10uf RB4 RD1/PSP1 8 5V R5 23 21 9 10K 18 RC4/SDI RD2/PSP2 22 10 9 C5 C1 17 RC0/SCK RD3/PSP3 27 11 10 10uf R9 13 RC0/CCP1 RD4/PSP4 28 12 11 10uf 22K 14 OSC1/CLKIN RD5/PSP5 29 13 12 OSC1/CLKOUT RD6/PSP6 13 5MHz 30 14 R6 C4 C2 1 RD7/PSP7 15 14 1K C7 47nF ~MCLR/VPP 5V 16 15 1UF 24 16 15 RC4/SDO RC0/TIOS0 8 R7 R10 16 RE0/RD 9 LCD 22K 2.2K RC0/TIOS1 RE1/WR 10 RE2/CS TL072CP 31 VSS -5V R8 C6 5V 12 33K 100nF 1 8 VSS C8 2 1 8 7 3 2 7 6 4 3 6 5 PIC18F4520 4 5 47nF C3 100nF C5 100nF +5V R13 10K LM358 R11 10K R12 1 8 R14 2 1 8 7 3 2 7 6 100 4 3 6 5 220 4 5 7486 +5V 14 1 14 13 R15 1K 2 1 13 12 3 2 12 11 4 3 11 10 5 4 10 9 6 5 9 8 +5V R16 1K 7 6 8 7 R17 1KFigure 2: Schematic diagram of Design and Development of Microcontroller based system for the measurementof Blood Glucose. 1441 | P a g e
  3. 3. N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.1440-1444Sensor unit with Biosensor Biosensor is connected to amplifier LM358 and According to the American diabetes ADC.Association (ADA) [8], the term diabetes mellitusdescribes a metabolic disorder of multiple aetiology Signal conditioning unitcharacterized by chronic hyper glycaemia with In general any Instrumentation systemdisturbances of carbohydrate, fat and protein consists of various units staring from sensors to datametabolism resulting from defects in insulin representation units, among that signal conditioningsecretion, insulin action, or both. The effects of is a vital process. The glucose measurementdiabetes mellitus include long– term damage, originates as a small current generated by thedisfunction and failure of various organs. Diabetes chemical reaction occurring in the test strip. The testmellitus may present with characteristic symptoms strip contains glucose oxidase, a chemical that bindssuch as thirst, polyuria, blurring of vision, and to D-glucose to start a redox reaction. The redoxweight loss. reaction breaks down the glucose and releases A biosensor is a sensor that makes use of electrons. The flow of electrons is known as currentbiological or living material for its sensing function. and is collected by electrodes built-in to the testThere are three main parts of a biosensor: (i) strip. The current is converted to voltage through thebiological detection elements, which recognize the use of a current-to-voltage converter.substance of interest, (ii) a transducer, which When test stripe is inserted PIC microconverts the biorecognition event into a measurable controller sense the presence of the strip. Thesignal and (iii) a signal processing system, which current output from the glucose test strip isconverts the signal into a workable form. connected to inverting input of the LM358 [9]. The The basic operation of glucose biosensor is LM358 dual operational amplifier, low power drain,based on the fact that the enzyme glucose oxidase a common mode input voltage range extending to(GOD) catalyses the oxidation of glucose to ground/VEE, eliminating the necessity for externalgluconic acid. The enzyme acts as a biorecognition biasing components. The current is converted to aelement, which recognizes glucose molecules. These voltage in LM358.A current-to-voltage converter isenzyme molecules are located on an electrode simply an op amp with a feedback resistor. The opsurface, which acts as a transducer. As soon as the amp is used as a high impedance source that forcesenzyme recognizes the glucose molecules, it acts as all of the current to flow through the resistor. Thea catalyst to produce gluconic acid and hydrogen average current I produced by the glucose test stripperoxide from glucose and oxygen from the air. The is 20μA. V is chosen to be 2 volts, then R = 100000electrode recognizes the number of electron transfer Ohmsdue to hydrogen peroxide/oxygen coupling. This The output of LM 358 is given to the filterelectron flow is proportional to the number of circuit. The filter circuit uses a TL072 [10] Lowglucose molecules present in blood. The glucose Noise JFET Input Operational Amplifier and issensor is an electrochemical diagnostic strip which configured as a 100 Hz Sallen-Key Low Passuses glucose oxidase enzymes in conjunction with Butterworth filter. The glucose measurement isthree electrically conductive electrodes. Two of taken from a single acquisition from the analog-to-these electrodes are „working‟ electrodes meaning digital converter. When a sample is applied to thethey are the measured electrodes, and the third is a test strip the voltage jumps to a peak value and thenreference electrode as shown in fig 3. begins to decay linearly between 1 and 5 seconds. The voltage reading is taken after 2 seconds the sample is applied. Fig 4 shows a typical voltage curve for glucose. Fig 4: Glucose voltage curve. The voltage level is then converted to a glucose concentration using equation Concentration = (voltage) x922.23− 22.9Fig 3: Schematic layout of a biosensor and test The Micro controller PIC 18F4520 is usedstripe to connect each component of the meter. TheThe signals from glucose sensor are transmitted to processor is responsible for the analog-to-digitalnext stage of signal condition unit. The output of the conversion, LCD control, user interface, and communication with a serial device. The 1442 | P a g e
  4. 4. N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.1440-1444microcontroller uses a 5 MHz clock. The analog-to-digital converter is configured with two controlregisters, ADCON0 and ADCON1. ADCON0 isused to configure the conversion clock, the inputchannel. The analog-to-digital converter is set up touse an Fosc/8 conversion clock, read channel 0, andturn the module on. The maximum device frequencyis 5 MHz.Microcontroller In the present study, we have usedPIC18F4520 [11] microcontroller for themeasurement of blood glucose. PIC18F4520 is anEnhanced Flash Microcontroller with PowerManaged Modes. The PIC microcontrollers havehigh computational performance with the additionof high endurance, Enhanced Flash programmemory. The PIC18F4520 introduces designenhancements that make these microcontrollers alogical choice for much high performance, powersensitive applications. it consists of Threeprogrammable external interrupts, Four inputchange interrupts, EnhancedCapture/Compare/PWM (ECCP) module, MasterSynchronous Serial Port (MSSP) module supporting3-wire SPI and I2C Master and Slave Modes,Enhanced Addressable USART module, 10-bit, 13-channel Analog-to-Digital Converter module, Dualanalog comparators with input multiplexing, High-current sink/source 25 mA/25 mARS-232 (Recommended Standard 232) is a standardfor serial binary data signals connecting between aDTE (Data Terminal Equipment) and a DCE (DataCircuit-terminating Equipment). It is commonly Figure 5: Flowchart for design and development ofused in computer serial ports. Here, we use MAX microcontroller based system for the measurement232 (RS-232) for serial communication in between of blood glucose.microcontroller and personal computer [12]. The PC is the standard computing device for the „C‟ compiler. [14]. to development of C programs for an PIC18F4520 executing on a PC isDisplay unit now familiar with MPlab IDE for Microchip [15]. The measured Blood Glucose data are The flowchart of the program is presented in Figuredisplayed on the Liquid Crystal display. In presentwork we are using LM16200 [13] (16 x 2 character) 5. A software method of digitally sampling theLCD display. The LCD connects to the concentration of glucose levels is described. The micro controller program controls the externalmicrocontroller using 14 pins. There are eight devices and measures the input signals from theparallel pins used for data transfer, three pins for sensor and displays the output. Figures 5 contain theenable, instruction/register select and read/write flow chart for the present designed instrument usedcontrol. The data and instructions are sent through to determine the blood glucose. When we insert aD0-D7 lines of LCD screen. glucose test stripe in the meter, the microcontroller Lcd displays requires less power and it isused display any alpha-numeric and symbols. The automatically detect the presence of stripe, when wedisplay has a built in controller with synchronous drop blood sample, it measure the glucose concentration and display the output blood glucose.serial and parallel interfaces. The display has alifetime of about 10,000hours. III. RESULTS AND OBSERVATIONB. Software The performance of the microcontroller „C‟ programme language is used for the based system for the measurement of blood glucosedevelopment of Blood glucose meter. The „C‟ is designed, developed and tested. Blood glucoseprogramming language is growing in importance values are illustrated on the two lines of the displayand has become the standard high level language for and transfer values to personal computer. Constantreal-time embedded applications. attention has been made on applying blood sample 1 1443 | P a g e
  5. 5. N. Anju Latha, B. Rama Murthy, U. Sunitha / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 5, September- October 2012, pp.1440-1444 micro liter of blood is the required for testing. The Ilse Milants, R.N., Mona Eerdekens, R.N., blood sample is applied correctly in a reaction zone; Pieter J. Wouters, Bart De Moor, and Greet the enzyme becomes active and mediator compound Van den Berghe, Journal of Diabetes transfer electrons to the electrode. Low power Science and Technology Volume 2, Issue consumption, long shelf life, and environmental 6, November 2008 operating characteristics (least affected by 2. “Fluoresence based glucose sensor”, John temperature, humidity, and pressure), were very .C.Pick up, Faeiza Hussain,Nicholas D important considerations in component and design Evan, olaf J. Rolinski,David J.S. Birch, Bio selection. The blood glucose measurements were sensors & Bio electronics, 20 (2005),Pg tested and the results are shown in Table 1. 2555-2565.S. Actual Blood ACCU CHEK Present designed 3. The UKDS study group: Intensive bloodNo Glucose values blood glucose Blood glucose glucose control with sulphonylueas or mg/dl meter mg/dl meter mg/dl Insulin compared with conventional1 93 93 92 treatment and risk of complications in2 136 134 135 patients with type 2 diabetes (UKPDS33),3 213 211 212 Lancet 1998;352:837-8534 183 182 182 4. The diabetes control and complications5 149 148 149 trial (DCCT): The effect of intensive Table 1: Blood Glucose values treatment of diabetes on the development and progression of long term complications The results of the present study are in good in insulin dependent diabetes Mellitus: the agreement with the standard blood glucose meters New England Journal of Medicine 1993; (ACCU CHEK & One Touch Ultra instruments). In 3299140:977-986 the present study, a microcontroller based system, 5. “Electrochemical biosensors – principles which converts the glucose concentration in the and applications”, Miroslav Pohanka1, Petr blood sample into voltages compatible with Skládal2, Journal of APPLIED microcontroller input requirements. The BIOMEDICINE ,57–64, 2008,ISSN 1214- microcontroller software determines the validity of 0287 the voltage and analyze. Once the test stripe has 6. Worthington, D. (1990). "Use of models in inserted in the meter, the glucose concentration the self-management of insulin-dependent corresponding to the applied blood sample is diabetes mellitus," Computer Methods and displayed as blood glucose. We got good accuracy Programs in Biomedicine, vol. 32(3-4), pp. when compared to YSI 2300 glucose analyzer [11]. 233-239. 7. Gabir MM, Hanson RL, Dabelea D, IV. SUMMARY Imperatore G, Roumain J, Bennett PH, The hardware and software features of a Knowler WC. Plasma glucose and microcontroller based system for the measurement rediction of microvascular disease and of blood glucose are described. The necessary mortality: evaluation of 1997 American software is developed in C, using MPlab IDE for Diabetes Association and 1999 World Microchip. The system is quite successful for the Health Organization criteria for diagnosis measurement of blood glucose with an accuracy of of diabetes. Diabetes Care. 2000 Aug; less than ± 2%. Our instrument protects data in the 23(8):1113-1118 event of power loss and does not require periodic 8. Definition, Diagnosis and Classification of refreshing. This feature would enable the health care Diabetes Mellitus and its Complications, team to use the recorded data to perform diabetes Part 1: Diagnosis and Classification of mellitus variability studies. In the present paper, we Diabetes Mellitus World Health used test strips designed for the One Touch Ultra Organization Department of glucose meter made by Life scan, PIC Noncommunicable Disease Surveillance microcontroller, RS232 for transferring data to Geneva WHO/NCD/NCS/99.2 personal computer for further processing and LCD 9. LM358 datasheet, www.national.com to display which operated with Less power and 10. TL072 datasheet, www.ti.com more bright. These are the novel parts when 11. PIC micro controller 18f4520 datasheet , compared to others. http://www.microchip.com(2008) 12. IC MAX 232 datasheet, www.maxim- Reference ic.com (2006). 1. “Blood Glucose Measurements in Arterial 13. Lcd datasheet www.lampex.com Blood of Intensive Care Unit Patients 14. RC-51 ANSI-C Compiler for the 8051 Submitted to Tight Glycemic family, “Reference manual” (2005). Control:Agreement between Bedside 15. Michael J Pont, University of Leicester, Tests”, Dirk Vlasselaers, Tom Van Herpe, “Embedded C”, Vol 1-2. 1444 | P a g e