Intelligent control system for medical devices based on RFID and ARM architecture
[Copy link]
Since the German physicist W.K. Reontgen discovered X-rays at the Institute of Physics of the University of Würzburg in 1895, which pioneered the diagnosis of human body effects, modern medical instruments have been constantly updated in the development of more than a century, and more and more new technologies have been applied to them. Especially today, with the increasingly developed science and technology, the great achievements made in computer technology, network technology, microelectronics technology, material technology, and biotechnology have all provided a technical basis for meeting the wider and more diverse needs of society, families, and individuals for medical instruments. In the future, medical devices will inevitably move towards miniaturization, intelligence, personalization, and networking. Modern medical instruments with a new concept will be "seamlessly" integrated into the community environment and personal families in 21st century, so as to better serve everyone's health. For
modern medical instruments to move towards intelligence, personalization, and networking, identity recognition is the first and most critical step. Radio Frequency Identification (RFID) technology, as a key technology of the emerging Internet of Things, can identify specific targets and read and write related data through radio signals without the need to establish mechanical or optical contact between the recognition system and the specific target. Based on this, a medical device intelligent control system based on RFID and ARM is designed to realize user information collection and medical device control. The system is currently mainly used in therapeutic medical instruments such as microwave physiotherapy instruments and ultrasonic physiotherapy instruments. With slight improvements, it can also be applied to physiological and chemical analysis and other detection and analysis medical instruments.
1 System overall design
The system uses ARM as the main control chip to complete the control of the radio frequency identification chip, information collection, data transmission and control of medical devices. MFRC522 is used to realize the reading and writing functions of the IC card. The host computer software developed by VC 6.0 is run on the PC to realize the control and access of the intelligent control system. The
overall design block diagram of the system is shown in Figure 1. The intelligent control system can read the user information under the set parameters and perform corresponding treatment and record. It can also be connected to the PC through the USB port and remotely control the treatment instrument. The setting and data collection of IC card and treatment instrument parameters can be read, written and managed by computer software.
Figure 1 Overall block diagram of the system
The system adopts a modular design and is divided into contactless IC card, intelligent control system, therapeutic instrument and PC with host computer software installed. By replacing different host computer software and therapeutic instrument (or analyzer), different medical instruments can be controlled. This design can realize the reading and writing and information storage of 500,000 IC cards.
2 System hardware design
The system hardware circuit is divided into four parts: the control subsystem with ARM chip as the core, the IC card reading and writing module with radio frequency identification chip as the core, the therapeutic instrument control module with MSP430F149 chip as the core, and the therapeutic instrument.
The ARM chip uses the STM32F107VCT6 chip, which is a high-performance product in the new STM32 Connectivity series of microcontrollers launched by STMicroelectronics. It uses the ARM 32-bit Cortex-M3 core. This chip integrates various high-performance industrial standard interfaces, and also has a full-speed USB (OTG) interface, two CAN 2.0B interfaces, and an Ethernet 10/100 MAC module. The therapeutic instrument control module uses the MSP430F149 as the main control chip. This chip is a high-performance product in the classic MSP430 series of microcontrollers launched by TI. It has a 16-bit reduced instruction set MCU and a command cycle of 125 ns. This chip integrates various high-performance industrial standard interfaces, and also has internal resources such as a 12-bit ADC, two 16-bit counters, and an on-chip comparator. It supports encryption functions such as serial number and fuse bit burning, which can prevent the product from being reverse engineered. The use of these two chips can improve system integration and stability, reduce PCB board area and system power consumption, and facilitate future system upgrades.
2.1 Contactless IC Card
Contactless IC card, also known as radio frequency card, consists of IC chip and induction antenna, which are packaged in a standard PVC card, and there is no exposed part of the chip and antenna. This technology is a new technology developed in the world in recent years. It successfully combines radio frequency identification technology and IC card technology, ending the problem of passive (no power in the card) and contactless, and is a major breakthrough in the field of electronic devices. The card is close to the surface of the reader within a certain distance range (usually 5 to 10 mm), and the data reading and writing operations are completed through the transmission of radio waves. Contactless IC card is a new type of smart card with the same functions as contact ID card and IC card, but it does not require power supply. The receiving antenna draws power from the magnetic field of the reader, and works to calculate data and feeds it back to the reader.
The contactless IC card itself is a passive body. When the reader performs a read/write operation on the card, the signal sent by the reader consists of two parts: one part is the power signal. After the card receives the signal, it resonates with its own L/C circuit to generate an instantaneous energy to supply the chip. The other part is the data signal, which completes data, modification, storage, etc. through the receiving chip and returns it to the reader. The read/write system formed by the contactless IC card has been greatly simplified in terms of both hardware structure and operation process. At the same time, with the help of advanced management software and offline operation mode, the data reading and writing process can be made simpler.
2.2 Control subsystem design
As shown in Figure 2, the control subsystem uses STM32F107VCT6 as the main control chip. The peripheral circuits of its hardware circuit include reset circuit, JTAG debugging interface, status indication circuit, UART interface, USB to serial port module, etc.
Figure 2 System Hardware Block Diagram
Reset circuit and JTAG debugging interface are indispensable parts of ARM minimum system. The status indication circuit is composed of LED, buzzer and TFT touch LCD screen, which can indicate the working status of the system, display the current user information, consumption, treatment plan and time, etc. At the same time, the touch function of the LCD screen can be used to manually set the system parameters. The UART interface can easily realize on-site debugging and multi-machine communication. Since most of the existing mainstream PCs are no longer equipped with RS 232 interfaces, the design of USB to serial port module can facilitate the communication between the control system and the host computer.
2.3 IC card reading and writing module design The
IC card reading and writing module uses Philips MFRC522 original chip to design the card reading circuit. It is easy to use and low cost. It is suitable for users of advanced applications such as equipment development and card reader development, and users who need to design/produce radio frequency card terminals. This module can also be directly installed in various card reader molds. The module uses a voltage of 3.3 V and can be directly connected to any user's CPU motherboard through a few simple lines of the SPI interface to communicate, which can ensure the module's stable and reliable operation and long card reading distance.
MFRC522 is a highly integrated card reader/writer chip for 13.56 MHz contactless communication. It is a low-voltage, low-cost, small-sized contactless card reader/writer chip launched by NXP for "three-meter" applications. It is a good choice for the development of smart meters and portable handheld devices. MFRC522 uses advanced modulation and demodulation concepts, fully integrates all types of passive contactless communication methods and protocols at 13.56 MHz, supports 14443A compatible transponder signals, digital part processing ISO14443A frames and error detection. In addition, it also supports fast CRYPTO1 encryption algorithm, which is used to verify MIFARE series products. MFRC522 supports MIFARE series higher-speed contactless communication, with a two-way data transmission rate of up to 424 Kb/s. As a new member of the 13.56 MHz high-integration card reader/writer series chip family, MFRC522 uses SPI mode for communication with the host, which is conducive to reducing wiring, reducing the size of PCB boards, and reducing costs.
2.4 Design of therapeutic instrument control module
The therapeutic instrument control module uses the MSP430F149 single-chip microcomputer as the main control chip, and the peripheral circuits include configuration circuits, clock circuits and control circuits. The specific implementation of the control circuit is determined by the control method of the corresponding therapeutic instrument. The therapeutic instrument control module can control the medical instrument to respond to achieve the purpose of treatment. Using MSP430F149 to design a special therapeutic instrument control module can facilitate system design and expansion. When replacing the therapeutic instrument, only the corresponding control module needs to be replaced, which simplifies the software and hardware design.
3 System software design
System software design includes two parts: embedded program and host computer software. The system architecture of embedded software is shown in Figure 3, including seven parts: system initialization program module, MSP430 system control main program, IC card reading and writing program module, therapeutic instrument control program module, host computer serial port communication program module, LCD control program module, status indication program module, etc.
Figure 3 Block diagram of embedded software system of Zhirui medical equipment industrial control deviceAfter
the system is powered on, the ARM chip receives the control signal and setting parameters sent by the host computer software through the UART interface, sends control signals to the IC read-write module and the therapeutic instrument control module, sets parameters for the IC read-write module, and starts the therapeutic instrument to realize the corresponding parameter initialization. When no host computer control command is received, the system can also call the stored parameters for system initialization, or set the system parameters by manually operating the touch screen.
During the normal operation of the system, if the user IC card is read, the user information and consumption information are checked, and the corresponding treatment can be carried out after passing. After the treatment is completed, the treatment effect will be stored accordingly according to the treatment situation and user feedback, so as to facilitate the doctor to read and formulate further treatment plans.
3.1 ARM Programming
ARM programming adopts the development environment IAR EWARM (IAR Embedded Workbench for ARM), and the program is written in C language. The ARM program flow is shown in Figure 4. The main program implements functions by calling each module program. First, each module of the system is initialized, and then the serial communication module program is called to read the operation instructions and data of the host computer, and then the corresponding operations are performed according to the corresponding instructions. After that, the IC card reading and writing module program is called to detect the card reading status of the system. If an IC card is inserted, the IC card information is read, but there is still a balance in the account, then the instrument is turned on for the corresponding operation. If there is no balance, it will display insufficient balance.
Figure 4 ARM program flow chart
3.2 IC card reading and writing program design
The IC card reading and writing module program module includes resetting and initializing the IC card reading and writing chip, and then the main control chip reads the card and performs anti-collision processing. After selecting the card, authentication is performed. After authentication is the IC card issued by the system, the corresponding command operation is performed: including card reading, card writing, value addition, value reduction, pause and other functions. Finally, it is judged whether to change the partition. If the partition is changed, the authentication is re-performed. If the partition is not changed, the command judgment is re-performed.
3.3 Serial communication module program design
The serial communication program uses interrupts to trigger serial communication. When the microcontroller serial port receives data, it enters the interrupt service program entrance, and then determines whether it is receiving data or sending data according to the register. If it is receiving data, read the receiving buffer data, release the receiving buffer after reading, and the interrupt service program ends; if it is sending data, write the data into the sending buffer, set the sending request bit, and determine whether the sending is completed. If the sending is completed, the interrupt service program ends. If the sending is not completed, continue to send until the sending is completed.
3.4 LCD control program design
The LCD control module program workflow is to first initialize the LCD and clear the screen, then set the initial value of the display line, point the display pointer to the first line, and send the data to be displayed into the buffer. At this time, the preset data will be displayed in the specified area, adjust the pointer, and point the pointer to the next line of the LCD to determine whether the display is over. If it is over, jump out of the function. If it is not over, return the value to display the preset data in the previous step, and continue to display the data corresponding to the next pointer. During the display process, the main program will call the touch function cyclically to determine whether the user has an operation. If there is an operation, the corresponding parameter setting and working status adjustment will be performed according to the user operation.
3.5 Design of therapeutic instrument control program
The working process of the therapeutic instrument control module program is: first initialize the internal resources and IO ports of MSP430F149 and initialize the working status of the medical device, then detect the card reading status of the system. If an IC card is inserted, read the IC card information, but there is still a balance in the account, then start the work of the medical device, and start the treatment according to the user's settings or call the set treatment plan. If there is no balance, it will display insufficient balance.
4 Upper computer software design
The upper computer software is mainly composed of two parts: dynamic link library and user operation interface program. The dynamic link library is implemented by VC++ programming, which is responsible for communicating with the serial port driver and responding to various requirements of the application program; the user operation interface program is implemented by MFC programming, which can realize the functions of initializing the device, setting instrument parameters, and controlling the operation of the device. The upper computer is designed as a green free installation version, which can reduce the requirements for computer configuration and reduce the difficulty of user operation. The upper computer software can realize the production of various function setting cards, the charge management of consumption cards, the collection and analysis of user data and treatment information, and various report output functions. The principles of upper computer software development and design are good, easy to use, reasonable and concise. It can not only reduce the difficulty and time consumption of user operation, but also reduce the training and maintenance time of developers
.
This paper designs an intelligent control system for medical equipment based on RFID and ARM architecture. STM32F107 is used to control the MFRC522 radio frequency chip to communicate with the radio frequency card, and a USB conversion chip is used to realize serial communication between the microcontroller and the PC. The system can identify the patient's identity information and consumption information through the radio frequency identification card, realize the retrieval and storage of user information and consumption information, retrieve the corresponding treatment plan for the corresponding patient, charge a certain fee after the treatment is completed, and record the treatment effect based on the patient's feedback. The system adopts a modular design, and the intelligent control system of various medical instruments can be realized by modifying the therapeutic instrument control module; by connecting multiple systems to the Internet at the same time and modifying the upper computer software, the operation and control of multiple therapeutic instruments can be realized.
This article comes from the Internet
|
提升卡
变色卡
千斤顶
