The Hardware Design Of Dynamic Glucose Monitoring Device Based On ARM

The development of diabetes (DM) is rapid, and it severely impair human body. The current treatment is regulating glucose metabolism of the patient, and the important basis of clinical treatment is the patient's blood glucose level, therefore, tracing and appraising diabetes' control through the blood glucose instrument are very important.The traditional vein blood glucose and the blood glucose instrument examination can only reflect the instantaneous blood glucose level, cannot reflect the patient complete blood glucose change and the tendency. In recent years, the micro-damaged, the no-created and the continuous blood glucose monitor meter have developed vigorously liking mushroom growth, but at present because it has some questions in the accuracy and stability, caused it to be still unable substitute tradition blood glucose instrumentation in the clinical. Dynamic blood glucose monitoring system is operated by the medical staff, which is used to collect the blood glucose dynamic change material of diabetic for 1 to 3 days. But this dynamic blood glucose monitoring system is not able to real-time display blood glucose levels with the equipment, patients can not understand their own blood glucose changes. The blood glucose data can only be shown on the doctor's PC after removing the equipment. This is inconvenient for the patients, so this paper design a blood glucose monitoring device, which can real-time display blood glucose data changes with it. So patients can observe their own blood glucose levels timely, and they also understand their state of an illness.The dynamic blood glucose monitoring devices is based on glucose enzyme biosensor technology and embedded MCU in this paper, and it carries out information collection, storage and real-time display of the blood glucose. The installation includes information collection module, information processing modules (including information storage, information display and transmission of information),software manage portion. The method is the hardware and software units. ARM embedded processor chip LPC2103 of NXP the core control of hardware portion, with the signal amplification circuits, data storage circuit, liquid crystal display circuit, keyboard control circuit, serial communication circuit, real-time clock circuitry and power management circuitry.The glucose content signal that is distilled from body fluid by the glucose sensor is extremely weak, and the voltage range is between 0mV to 0.6mV.However, SCM System A/D converter input voltage range is 0V to 3.3V,so first the glucose content signal will be send analog signal amplification circuit to enlarge treatment, after enter ARM embedded processor chip processing unit. The analog signal can be switched to numeric signal through SCM ADC12, besides the data and waveform changes in blood glucose levels will be displayed on the LCD, and the data will be stored in memory. The data can also be transmitted to PC by serial interface of Equipment. The doctors can analysis state of an illness and confirm treatment scheme by dint of data and waveform shown on PC.The device information processing module is made up of LPC2103 control chip, peripheral interface chips and other digital circuit. The LPC2103 is very small and low power consumption, so it is very suitable for the applications whose main requirement is miniaturization. The mix serial communication interfaces composed of multiple UART,SPI to SSP and two I2C bus operate with SRAM of 8kB together, and it makes LPC2103 be very suitable for communications gateways and protocol converters, math coprocessor and a strong buffer processing functions of large enough space. The number of 32 and 16-bit timers, a modified 10-bit ADC,PWM properties and 32 fast GPIO make it be suitable for industrial control and medical systems especially. LPC2103 contain an SPI controller. SPI is a full-duplex serial interface for handling in multi-interconnection master and slave of a given bus. The Olympic logo and "concern Olympic and health" are displayed automatically after booting device. Then device enter the main interface after nine seconds, displaying battery, blood glucose values, time and blood glucose waveform changes.LPC2103 is based on a supporting real-time simulation ARM7TDMI-S CPU, and it has an 8kB and 32kB embedded high-speed Flash memory. The 128 width memory interface and the unique structure make 32-bit code can run on the maximum clock rate. This can make the performance of important function in the break service procedures and DSP algorithms increase 30% than Thumb mode. The application of controlling the size of the code strictly can use 16Thumb mode to reduce the size of code more than 30%, and the loss of performance is very small. The program codes are stored in on-chip static RAM and on-chip Flash memory in this device. Since the blood glucose monitoring devices transmits nine data per minute, and total data stream are diabetic blood glucose information and data of three days, the on-chip Flash capacity can only meet code storage, so it is need to expand an E2PROM to store blood sugar data in an external. Expanded chip is CAT24WC32 which is a 32bit serial CMOS E2PROM and internal contain 4096 bytes. The liquid crystal display of the device is Nokia 6100,and its main parameters is:132*132pixels;12-bit color display (4-red,4-green,4-blue);3.3volts;9-SPI serial Interface(clock or data signals).Its graphics controller are Epson S1D15G00 and Philips PCF8833.The Epson S1D15G00 whose interface is SPI is used in this paper. The part of the keyboard adopt A/D scan, and A/D voltage value is supply voltage which is separated, hereby the keyboard scan could be determined. There are two main keyboards, which are the launch button and combination keys respectively. The start button BP9 will control system startup and A/D converter. The combination keys will adjust the various options, including the time set button BP8,storage keys BP6,backspace key BP5,shifted to right button BP3,up and down keys BP7 and BP4.Serial interface module of device will be mainly used for transmitting blood glucose signal to the doctor's PC.MAX232 unveiled by Texas Instruments is a standard RS232-compatible chip. As computer serial RS232 level is -10Vto +10V,but general signal voltage of SCM application is TTL-level 0V to +5V,and MAX232 is used for voltage conversion. When in normal or idle mode, real-time clock provides a set of measuring time counter. RTC power consumption is very low, which makes it be suitable for battery-powered system whose CPU dose not work continuously.This system software development is based on Keil for ARM development environment. Keil uVision debugger can debug ARM chip peripheral functions accurately. ULINK USB-JTAG converter connect PC-USB port with the target hardware, and the code can be debugged in the target hardware. It is easy to edit, download, and test embedded procedures on the actual target hardware by using Keil uVision IDE debugger and ULINK USB-JTAG converters.After the development completes, the test and the experiment to instrument's performance has carried on. The test result satisfies the design requirements basically. This system can carry on a series of processing to the gathering blood sugar signal, including A/D transformation, the data storage, the data and the wave display, the serial port transmission and so on.This article innovation lies in the display aspect. This kind of product cannot display the real time blood sugar value in the former, but this system can not only display the real-time blood sugar value but also display blood sugar wave of a period of time on the liquid-crystal display. It is possible to let the diabetic observe own blood sugar value and the change situation clearly, and they could understand their own condition.