Flow meter dynamic power management module design

Introduction

And other portable electronic products, hemodynamic parameters gauge to be compact and slim, durable, reliable performance, and standby time is long.

Therefore, a system designed to reduce power consumption and battery life of daunting challenges. Power management module is a very important part of the system, it includes battery charger, battery testing, CPU state transitions, LCD and keypad backlight control. This article from the hardware and software design two angles to achieve these features.

Large practice has proved that the system idle time total running time of a majority.

Power management is to reduce the system idle time of energy consumption, make energy efficient embedded systems to maximize the supply rate, thereby extending battery life. In order to extend battery life, in the hardware field, low-power circuit design methodology has been widely applied. However, the mere use of a low-power circuit still not enough, in system design, the use of "dynamic power management" concept, that is, the system is not in use by the component to close or enter low power mode (standby mode). In addition to a more efficient approach is to dynamically variable voltage DVS and dynamic variable frequency DFS, in run-time dynamic adjustment of the CPU frequency or voltage. So you can meet instantaneous performance, making the effective rate of energy supply.

1 system design

The entire instrument design uses S3C44B0 chip and uClinux OS.

S3C44B0 chip is industry application, lower power consumption, low cost of mid-range products. It provides five kinds of work status: NORMAL, SLOW, STOP and IDLE, SL_IDLE [1]. The system works in the NORMAL state, when a user without operating window larger than a certain threshold, you go to the IDLE state, the user presses enter False shutdown, then STOP State system power consumption is very low. For ease of administration, application layer on the power management State had a fine Division, the introduction of power management in six States: data collection status, functional status, readiness, rest State, IDLE status and STOP State. Among them, the IDLE status and STOP State and chip provides the same content, the application is responsible for the status of migration. The entire instrument power is the largest component is backlight (EL backlight and keyboard LED), LCD and sensor-driven, followed by CPU, power management state migration as shown in Figure 1.

Figure 1 system power management state migration

1.1 power management model

Figure 2 is a power management principle diagram, which consists of six modules: Vcore, Vio, Backup, Charge, Vdriver and Vlcd, they are part of the system.

Figure 2 system power management diagrams

Vcore-system kernel power supply voltage V 1.8; Vio is the system's i/o port power supply, power supply voltage for system Backup 3.3V; backup battery, battery voltage: 3 V; Charge the battery for charging circuit voltage of the battery; 3.6V Vdriver sensor power supply circuit, voltage ± 5 V; power for LCD module Vlcd, power supply voltage is 3 .3V and 200VCA.

Battery charging circuit principle: when the CPU detects that there is an external power supply, CPU use ADC detection voltage battery 2-side, and determine the need to charge; when the battery voltage falls below the specified value, the open circuit Charge to the battery charging current, and testing to ensure that the battery charger, safely and effectively in charge to set value to stop charging; no external power supply, battery, power supply for the entire system CPU detection, when the battery voltage falls below a set voltage, decide whether the alarm, in order to protect the battery.

Vcore and Vio respectively to the system's kernel and i/o port power supply, power supply for memory Vio.

Backup battery backup battery for the system.

Provided for the sensor Vdriver ± 5 v voltage, and current 25 ± 1 mA.

Vlcd for LCD module provides two groups of voltage, V for LCD display 3.3 provide voltage, the LCD backlight 200VAC provide voltage.

1.2 driver design

1.2.1 driver interface

System hardware power management module for system power management function of providing the necessary hardware, infrastructure, and as a driver with the following programming interfaces:

¡Ô system power supply interfaces, this interface drivers and applications to know the system at this point is the battery or external power supply;

◆ Battery testing interface through this interface driver can be detected by the system of power, the application can implement the system battery display and battery alarm;

◆ Battery charge status, when the system uses an external power supply, available on the system battery, adopted this interface driver to get the battery charge status (charging or battery is full);

◆ Battery temperature detection interface through this interface driver detects the temperature of the battery, the battery temperature and battery power available to calculate the combined battery usage time, while in battery overheating (battery) alert the user when to alert the user to shut down or replace the battery.

Power management-driven part of the principal to the upper level provides the following interfaces.

(1) the battery and system electricity consumption

Read through the port ADC1 battery voltage.

Maximum voltage to lower voltage, V 4.2 3.6 V, alarm voltage 3.6 V, forcibly shutdown voltage 3.4V. A number ofAccording to voltage relationship: 1024-5 V, 0-0 V.

Battery charging management consists of the hardware, but the battery charge to 4.2 v, delay 30min off charging function (application layer).

Control port is GPC1, 1 for an external power supply, 0 is on battery power.

In the system with an external power supply, the system by an external power supply.

(2) battery charge control

Control port is 0 for charging GPA9,, 1 to turn off the charge, when battery power is less than 3.8 V, GPA9 is set to 0, and start charging (application layer).

5V power supply is used only for data acquisition, data collecting State closes 5 V power supply (ADC).

Control port is the GPC2, 0 is open, 1 to off.

(3) false shutdown

Shut down state, just close the keyboard lights and LCD screen, but the system is still in the running state.

Close the keyboard lights, LCD, and other peripheral devices work by top software.

1.2.2 program process

UClinux startup called module_init (Power_44b0_init) function, which in turn to the called power_44b0_init, related to initialize:

◆ Power0_44b0_reg_init () initialize the hardware registers;

◆ Power_44b0_device_register () register power_44b0_fops and interrupt handler function power_key_44b0_interrupt (), and initialize the timer power_down_timer;

◆ The user program by power_44b0_open () function to open/dev/power device through power_44b0_release () function frees/dev/power device through power_44b0_ioctl () function to achieve various actions on the device;

◆ Shutdown into stop mode, the interrupt handler function power_key_44b0_interrupt () handles shutdown key corresponds to the interrupt, press the down key when using power_down_timer timings, 3s, power_down_timer corresponding actions occur, power_down_timer_call () to enter the stop mode.

1.2.3 interface design and interface function

(1) data structure description

Power and device status indicated by power_status_t results.

(2) the value of the file_operations

Power management module-driven file_operations specific values are:

(3) design power_44b0_ioctl () function

Function prototype: static int power_44b0_ioctl (struct inode *, struct inode file * filp, unsigned int cmd, unsigned int arg).

Function description: the device ioctl operation function.

Parameter description: inode, the file pointer, perform an action type, according to the action type to specify a different parameter.

Return values: 0 for success, otherwise return ENOTTY.

Determine the value of the cmd, according to the different values of cmd different actions, the power supply of the main achievement of the following ioctl: 14

（4）power_key_44b0_interrupt

Function prototype: static void power_key_44b0_interrupt (int, void * dev_id irq, struct pt_regs * regs).

Function description: response to shut down key, enter the stop mode.

Parameter description: interrupt, device id, register structure.

The following describes the functions of the algorithm description.

In a normal state:

2 Summary

Instrument configuration of Ni-MH battery 2200mAh, tested, and power management module allows the entire system of 60% less power.

System in the data collection status, output current from the battery to approximately 220mA; if it is in IDLE state, the current total consumption to 80mA; in STOP State (close ARM and all equipment, maintain a 32768 Hz clock), the current can be reduced to 10mA. Experiments show that the use of dynamic power management, portable medical devices enable efficient power management.

Reference documents

1 horse-Mei.

ARM embedded processor architecture and application infrastructure. Beijing: Beijing University Press, 2002

2 Xu Hai-yan. Embedded systems technologies and applications. Beijing: China machine press, 2002

Medical industry how to face the impact of the Internet age

As the network technology, information and communication areas of rapid development, the network economy, knowledge-based economy is no longer a IT and other high-tech industry patent, nowadays the process of rapid development, Web technology has on the social, economic and cultural aspects have a significant impact on, and will change the way people know the world, thinking about the world of ideas and methods.

As one of the traditional industry, medical industry, how to face the impact of the Internet era, how to take advantage of network technology to improve our health care industry's management level and service quality, is an unavoidable problem. In order to carry out the Ministry of health on speeding up health systems information construction and management of the spirit of the meeting, further medical information development of the industry to understand international medical information development dynamic, absorb new technology and management experience, improve the health system information application for the management level, the economic and social benefits to hospital bumper, provinces are gradually accelerate the pace of the hospital Informationization construction.

Medical industry application needs analysis

Establishing information systems was designed to solve the problem of the existing system.

In information systems development, it is first necessary to define the goals and problems to be solved, in the process of setting and various features of the design closely around the goals. We from the following aspects of hospital information systems objectives and requirements:

1. the needs of hospital managers

Hospital managers are concerned, the system runs a macro on what kind of benefits can be seen, but on a specific application to have the kind of features do not pay attention to.

These benefits does not necessarily mean direct economic benefits, but rather HIS resolve some manual management cannot or difficult problems for managers informed of hospital operations, conduct scientific policy to provide accurate information. The hospital management to medical management and financial management.

As a perfect hospital information system, on the one hand, to be able to establish a set of reflect hospital medical and economic health indicators and routine; on the other hand, the system will run directly in order to improve the hospital's management services.

2. system directly to users ' needs

The system of direct users care about is a system-supplied function to their business if there is a direct help, the system is easy to use, including the operation is simple, easy to learn, fast response, etc.

In system design and implementation of specific, required system does not simply provide additional, delete, replace, search function, but for the specific application, for each type of business with all of the features of the design.

3. system maintenance personnel requirements

System maintenance including data backup, recovery, and error data corrections, etc.

Information system once put into operation, the maintenance support sustainability becomes a system up and running. As an online transaction processing system, hospital information system requirements to run 24 hours a day, 7 days a week to run without interruption. As out-patient charges, registration system, if the disruption, its consequences would be unthinkable, but definitely not allow data loss. In the day-to-day running of the system, often have to correct the error data, update data, and so on, need to maintain staff intervention. If the system serviceability is not good, will inevitably lead to maintenance personnel is busy with day-to-day coping, heavier burden for more back.

To resolve this problem, we believe that the system serviceability as a basic requirement into the product development process.

On the one hand, for common data error, check the correct means should be provided.

The demand is from the user perspective on the requirements of the final operating system.

The development and construction of the system, the user on the network, servers, operating systems, platforms, system stability and reliability also have specific requirements.

4. on the network and run the platform requirements

Application structure and function of the software reflects the target business functions.

To really make the system run stable reliable, meet user's expectations for the entire system, establish a set of characteristics and compliance with hospital requirements, can provide the required bandwidth and performance, stability, has a fault-tolerant network system is very important. Network cabling structure and the use of the media should also be realistic and be able to meet a certain period of development needs. In addition, network operating systems, network protocols, such as a database system should meet the requirements of the application software.

Small hospital procurement analysis

Small hospital campus network with fast Ethernet (100M) as the backbone, 10M to your desktop.

It has the following characteristics:

1. the exchange of high-performance, full-

1000M high volume server connection 10/100M or 10M connection desktop users can support a long cable connection between doing office building 2. scalability and strong

GBIC slot provides low cost gigabit connections between switch and wiring through gigabit stacking expanded user number (optional) modular routers can be easily expanded with new features, the port types and number 3. system security, confidentiality and high

Small hospital of low-cost solution for a router's built-in firewall IOS software firewall on demand Division virtual network, management of handy switch-based ACLs, port security 4. simple to manage

The whole network in the low-end switch configuration for a single cluster, a single IP address management domains, a single management objects based on IOS unified human machine command interface

5. flexible, efficient, reliable WAN connection (optional)

Support for multiple WAN links: DDN, FR, ISDN, etc. support data, voice, video and more business integrated rich bandwidth optimization technology: QoS, on-demand dialing, on-demand bandwidth link compression methods such as cost reducing link, protect critical and immediate business 6. use of wireless products for Mobile Office (optional)

Wireless architecture supports mobile Internet and e-mail access supports up to 11M transfer rate support structures and buildings application between

A new intelligent fetal monitoring system

Fetal monitoring is to safeguard the perinatal and fetal safety, achieving an important means of eugenics. Smart fetal monitoring is based on the monitoring indicators of fetal health, auto take corresponding measures of care. Introduces the comes with 24-bit A/D converter core devices MSC1210 microprocessor, wavelet analysis algorithms process the data key for the technical and comparative analysis of the monitoring indicators adopted, using alerts, tips, and start shaking the device mode to alert and auto take corresponding measures of intelligent computer fetal monitor system. Clinical trials show that the system has high detection accuracy, better real-time and accurate, and friendly intelligent control. 1. introduction of perinatal and childbirth on the fetus for guardianship, can detect intrauterine hypoxia, distress and other severe symptoms, reduce fetal mortality, to improve the quality of delivery. Traditional fetal monitoring system is complex, high power consumption, human disturbance, and not for family care and self care. Smart fetal monitoring system using TI company with 24-bit A/D converter and a simulation performance and digital processing power of a microprocessor, the microprocessor MSC1210 input channel select, buffering, amplification, gain adjustment, A/D conversion and digital processing integrated into monolithic circuit, with only one piece of integrated circuits for fetal heart rate, uterine contraction pressure and FM frequency of monitoring indicators of data collection and on voice, sound and vibration control. Intelligent control of fetal monitoring is based on the fetal heart rate, how to accurately and timely received fetal heart rate is the intelligent control of fetal monitoring system. For Fetal Doppler signal to noise ratio with low, non-stationary characteristics of randomness, calculation of the fetal heart rate when 1/2, 2/3 and 2 x heart rate, causing the application to control failures, here combined with the double threshold of wavelet analysis algorithm, accurate, real-time received fetal heart rate, ensuring effective intelligent control. 2. intelligent computer fetal monitor system hardware design 2.1 intelligent computer fetal monitor system structure smart computer fetal monitor system block diagram shown in Figure 1. Mainly by Ultrasonic Doppler fetal heart detector, uterine contraction probe, probe, fetal heart FM signal conditioning circuits (low-pass filtering, absolute value calculations and envelope extract, etc.), uterine contraction pressure signal conditioning circuits, voice control, acoustic, MSC1210 microprocessor and computer processing system. To MSC1210 and computer processing system at its core. MSC1210 control monitoring indicators for the collection and communication, the receiving computer commands control the audio devices and sound vibration. Computer system for intelligent control, communication, control, data processing algorithms, guardianship of the display function modules. 2.2 signal conditioning circuitry for fetal heart rate monitoring indicators of the importance and complexity of Fetal Doppler signal, here focuses on the Fetal Doppler signals coherent circuit. Circuit main on Doppler fetal heart sounds for low-pass filtering, absolute value calculations and envelope extract, pretreatment. Low-pass filter with cutoff frequency for 250Hz second-order low-pass filter to filter out high frequency signals and interference. Absolute arithmetic circuit shown in Figure 2. Signal strength enhanced doubled, increasing the detection sensitivity. Envelope extract circuit shown in Figure 3, using the cut-off frequency is 10HZ P-shaped filtering and t-shaped filtering based on the combination of low-pass filter. Parallel of diodes and capacitors on the circuit of a negative signal for restrictions and on a certain band of high frequency vibration signals. 2.3 MSC1210 microprocessor smart fetal monitor acquisition system uses United States Texas instruments company launched features a strong single-chip microcomputer MSC1210 as processor, MSC1210 chip integrated 8051 microcontroller and FLASH memory of precision touch number converter that chip uses Enhanced 8051 microcontroller core, reducing the instruction execution cycle, use a low-power design, internal integrates a 24-bit resolution analog-digital converter (ADC), the conversion rate of up to 1000HZ, 8-channel multiplexer, analog input channel test current source, the input buffer, programmable gain amplifier (PGA), the internal reference voltage source, 8-bit microcontrollers, Flash memory program/data and data SRAM, etc. Digital filters to filter the output of data. Digital filters with fast, sin2 and sin3 three. Enhanced 8051 kernel has two data pointer, the instruction system and standard 8051 instruction system fully compatible, its execution speed is 3 times faster than the 8051, so you can work in low frequency, to reduce power consumption and noise. In order to reduce interference, its simulation power and digital power supply separately. Because the chip integration enables intelligent fetal monitoring system hardware circuit easier, circuit design more compact, chips are very few external components, making the system's reliability has been greatly improved, but also significantly reduces the development cycle, lower development costs. MSC1210 interface circuit shown in Figure 4. Doppler fetal heart signal and uterine contraction pressure signal IN0 and IN2 input, via multi-channel converter after being fed into the buffer variable gain amplifier to zoom in on an input signal. FM signal by MSC1210 interrupt handling. Receive via RS485 bus MSC1210 PC release of control commands, the P2 port control voice chip complete voice alert function, through the vibration of sound P1.7 control complete automatic wake-up feature of fetus. Adopt more as microprocessor MSC1210 can get accurate, real-time, fetal monitoring indicators for the intelligent control. 3 Smart fetal monitor computer control system for computer control system using Visual C + + 6.0 development environment for programs that run in the context of the Win2000. For systems with large amounts of data and real-time performance requirements, system programming, making full use of the multiple threads of thought. The entire system is set up to five threads, which manages the user interface, responding to user actions in the thread as the main thread, the life cycle for the entire program of main memory, the other four threads for intelligent control, communication, control, data processing algorithms, monitor display function, lifecycle is the thread function itself. Multithreaded application, the thought of various functional modules of the system running in parallel, you can significantly increase the CPU utilization, meet the requirements of the systems real-time. Where data processing algorithms and intelligent control is the control system gatewayKey. 3.1 coif5 wavelet based fetal heart sound data processing algorithms on type description, Discrete Wavelet transform is the signal in the wavelet function on the projection, m, n represents a different resolution (scale) and various time-frequency (Pan), wavelet function is precisely through different m and n to adjust different local time-frequency and different resolutions, namely Wavelet Multiresolution analysis features can signal in different scales for multi-resolution decomposition, and the interweaving of all kinds of different frequency components of mixed signal into different frequency bands of signal, the signal is processed according to the band. Application of wavelet analysis for signal noise reduction is a Wavelet analysis of a very important one for the application. A noisy one dimensional signal model can be expressed as:: s (I) as a true signal; e (I) for noise; x (I) the noise signal. In a real project, useful signal is usually manifested by low frequency signal or a stationary signals, noise is characterized by high-frequency signals, noise cancellation process can be handled by the following methods. First of all on the actual signal for Wavelet Decomposition, choose Wavelet Decomposition level is determined as n, then the noise section typically contains at high frequency. And then on Wavelet Decomposition of high frequency coefficient threshold threshold quantify. Finally according to Wavelet Decomposition coefficient of n-tier low frequency and quantified after 1 to n-tier high frequency coefficient for Wavelet reconstruction, the purpose of eliminating noise, noise suppression of signal, the signal of the actual real signal in recovery. Ultrasound Doppler fetal heart sounds after signal conditioning circuits, signal in the frequency range of 0-500Hz containing less than 4 Hz frequency of fetal heartbeat, so the signal waveform analysis and fetal heart rate calculations should signal low frequency information, instead of high-frequency information; CWT's Multiresolution analysis features as the scale by thicker, gradually to a low frequency signal frequency, from details to smoothing the results of a series. You can use wavelets Multiresolution analysis characteristics, through selected appropriate Wavelet Decomposition level, optimization, separation of high frequency Doppler fetal heart signal and low-frequency components, parts and all the high frequency part, get contains all the information of the fetal, low frequency part through low-frequency signal frequency and calculate the fetal period, the fetal heart rate. This system through a number of experimental and theoretical derivation using Wavelet function. Application of wavelet have orthogonality, approximate symmetry, the better the smoothness and the regularity of advantages through 6 layers of Wavelet Decomposition extraction, get 6 8Hz following layer of low-frequency signal. At this time-frequency signal is basically the baby's heartbeat. Because of the random noise interference, you must extract the wavelet algorithm to the fetal heart sounds, this article uses a dual threshold to identify noise. First calculate the amplitude threshold, the calculation formula is: 3.2 computer fetal monitor smart control for previous fetal monitor only doctors through research monitoring curve graphics to inform fetal health, increased workload, is not conducive to home care. Smart fetal monitoring is focused on fetal monitoring intelligent. The theoretical basis of intelligent monitoring are mainly based on the measured fetal heart rate and clinical experience. Main interface color graphics logos, voice prompts and fetal wake-up control. In order to increase the intelligent control of security and stability, the fetal heart rate monitoring is an average over time, while size can be set via the interface itself. Fetal heart rate was also affected by the State for fetal wake-sleep, fetal acoustic stimulation can awake from sleep go, causing fetal movement, fetal heart rate changes, to learn about prenatal security is significant. Therefore this system is based on the fetal heart rate detection automatically starts the fetal acoustic stimulation of the wake-up, resulting in more valuable fetal monitoring graphs. Table 1 gives the smart fetal monitoring system of the fetal heart rate monitoring and intelligent control of the CRT.

Table 1 fetal monitoring intelligent control measures table

Fetal heart rate (bpm)

Clinical classification

Smart control measures

>180

To spend speed

Red logos, voice prompts

160-180

Mild too quickly

Yellow logo

120-160

Normal heart rate

Green identification

100 ~ 120

Mild slow

Yellow logo

<100

Severe slow

Red logos, voice prompts, start, acoustics and vibration

Adjacent heart rate > 25

Umbilical cord compression

Blue logo, voice prompts

More fetal heart rate is the value of clinical experience, care doctor may, in accordance with the actual situation of pregnant women, you can also set the scene for setting or cancel these intelligent control.

4 conclusions

Intelligent computer fetal monitor system using high-speed sampling MSC1210 microprocessor and communication, combined with a dual threshold coif5 Wavelet extraction of the fetal heart sounds, and joined the intelligent control.

According to the above principles and framework design of intelligent fetal monitoring system with high accuracy, high anti-interference ability of real-time performance, and suitable for home care, reduce the workload and improved perinatal clinical value of fetal monitoring.

Reference documents

[1] Cheng Chi thick. Song tree Liang. Fetal monitoring studies. Beijing: academic press, 2001.3

[2] Miss macros bin. Fields Institute naxin .MSC121X system-level SCM theory and application: machinery industrial press, 2004.2

[3] he Li-min. He Li-min .MCS-51 series single-chip application system design £ ® Beijing: Beihang University Press, 1990

[4] Hu Angel. Xiaomei. Multi-channel MSC1210-based high-precision temperature acquisition system module. Beijing: electronic technology, 2003.11 (7): 36-39.

[5] what Eric. Dongfang Peng. Practical Visual C + + 6.0 tutorial: Tsinghua University Press.

2000.9

[6] Cheng zhengxing. Wavelet analysis of algorithms and applications. Xi'an: Xi'an Jiaotong University Press. 1998.5

[7] Mallat S, Hwang W. Sigularity Detection and Processing with Wavelets IEEE Tran on Information Theory,1992,38(2):617-643.

[8] Mallat S.

A Theory of Multiresolution Signal Decomposition: The Wavelet Transform. IEEE Trans on PAMI,1989,11(7):674-693.

The blood pressure of ECG monitor USB interface design

Introduction home blood pressure monitoring system and Electrocardiograph from acquisition and record device and PC electronic case management system, therefore, need to address the problem of data transmission.

Traditional communication interface with a simple RS-232 serial UART, this way slow and bad fit, while the USB transfer serial chip transmission performance cannot been fundamentally improved. USB interface is a fast, easy to scale and support hot-plug, easy to use and flexible, especially for household equipment and computer communication connection.

This article focuses on USB communication protocol and interface chip control method for clinical needs, design and realization of the intelligent with ECG, blood pressure monitoring, USB high-speed data transmission function of miniature devices, providing ECG, blood pressure data electronic medical record query, printing, and network transport functions, for improving family health-care level is very important.

Monitor's USB interface circuit design system main control chip uses 32-bit high-performance embedded ARM microprocessor S3C44B0X, USB dedicated control chip selects the USBN9603.

USBN9603 built-in 7 FIFO ports, including 1 bi-directional control port, 3 3 send port and receive ports, each with 64 bytes.

USB controller and S3C44B0X interface circuit shown in Figure 1.

The USB controller is designed to store the nGCS2 Bank2 selection line as the USBN9603 slice alignment, the chip-chip selected address 0x4000000. This article uses the parallel data interface, two chip low 8-bit data cable connected D0 ~ D7, parallel transmission communication data. The MODE0 MODE1 pin are grounded and, configure the USBN9603 as non-multiplexed mode, because this mode requires the address lines A0 as access USBN9603 chip register DATA_IN, DATA_OUT and ADDR register select line, connecting the 32-bit address bus of the A18 to USB controller A0. The USBN9603 to read and write, is divided into two bus cycle: first of all, reset the address lines A0, namely to set high bus address for access will be 0x4040000 register address from cable D [0: 7] write, this is the first bus cycle will address to the chip; then, in the second cycle, low, i.e. A0 reset set the bus address read-write for 0x4000000, D [0: 7] can be realized on the registers of read and write operations. The entire USB communication process mainly dealt with include receiving, sending data and other disruption event, the USBN9603 int pin connected to the external interrupt S3C44B0X EINT0 pin, set USB interrupt-vector interrupt request mode. Because it does not use DMA, DACK reset, DMA request line DRQ vacant. USB cable has 4 wires, D + and D-is USB differential signal line, the other two are 5V power and ground wire. USBN9603 support low-speed and full speed USB communications, at D + signal cable connection 1.5 K Ω pull-up resistor to work at full speed mode.

Figure 1 system extended memory and USB interface schematics monitor's USB interface firmware implementation USB communication process is started from the host, in accordance with the agreed time to issue a token packet that contains the operation type, direction, peripherals, address and endpoint, and other information, and then specify the token data sender sends a packet or pointed out that no data transmission.

And USB peripherals to respond to a confirmation packet, indicating that the transfer was successful. This article uses the master-slave USB communication structure, the host computer by sending various prior agreement good protocol commands, to achieve the ECG, blood pressure data collection and to initialize the settings of the system equipment, mainly include the following data: ECG data to segment and each segment including 32KB ECG data and 6B acquisition time information, each transport segments, the amount of data, the transmission reliability requirements are high; blood pressure data including the diastolic pressure and systolic blood pressure and its acquisition time, 10B, because blood pressure monitoring more frequently, every time will transfer time of blood pressure monitoring data, the amount of data is also relatively large; download the upgraded version of the firmware, and other file information. These three data flows are relatively large, and reliability requirements are higher, three data selection block transmission channel types, in addition, each USB transfer will have control of the transmission channel. Therefore, you need to use three channels, namely the control channel, BulkIN channel and BulkOUT channel. USB firmware data structure this article relates to the USB device configuration enumeration phase super-computer in control transmission requires device transfer 4 class descriptors, in a hierarchical order: the device descriptor, the configuration descriptor, interface descriptor and endpoint descriptors, which, compared with higher-order descriptor will notify the host any other low-level descriptor information. Device descriptor is in the device connection host first read descriptor, each device can have only one device descriptor that contains the entire device and the device supports configuration number, total 18 fields. Each USB device has one or more of the configuration descriptor that contains the device power management and device configuration supported interface numbers, when the device receives get configuration descriptor's request, transfer the configuration descriptor and all the interface and endpoint and other ancillary descriptor to a host, this article sets a configuration, the descriptor of 8 fields. Interface contains a set of endpoints, the paper sets an interface, the descriptor has nine fields, as the host computer provides equipment use endpoint information such as the number and types. Each interface descriptor has zero or more endpoint descriptor that contains the host and endpoint to communicate the required information, endpoint 0 as a control endpoint to an endpoint of communication, 1 and endpoint 2 respectively block transfer mode, the descriptor contains endpoint number, transmission direction, endpoint transport type, maximum transfer byte packets. USB firmware communication processesUSB firmware framework process as shown in Figure 2, after entering the communication module, the firmware first calls the initialization routine, configure USB device, and make it into working order, and then enable interrupts, USB communication's main function is to interrupt the service, the main program is in a loop waiting for exit key, when break signal is detected, you are ' clicking ' to interrupt service routines, according to the register value judgment MAEV interrupt type, and enter the appropriate process. Figure 2USB firmware framework device USB communication mainly for ECG and blood pressure data Bulk transfer function. In the USB transceiver data communication protocols based on the monitor there is a specific application-layer communication protocol. Firmware receives user communication command, analytical control command and execute the corresponding routines. As transmission of ECG and blood pressure data command 0x10, firmware after receiving the order code 0x10, obtain from the command parameters be transmitted data length, select the ECG or blood pressure and its transport signs record number and other information, based on record number call GetRecordData (), Flash store to find data and stored in the send buffer BulkState, if transmitted ECG data you need to get through the Gettime () which ECG data acquisition time. All question to send data when you are ready to begin the transfer, as the Bulk transfer of maximum buffer to send 64B, first data, and then in 64B TX_EV routine to determine whether the receiving host computer, and if successful you successfully transfers the next batch of block input transaction, you will need to repeat, repeat the above process until loop data sent.

USB firmware module routine to initialize the USB interface initialization routine, including the USBN9603 chip initialization and user variables initialized after device enumeration.

During the initialization phase, the firmware needs to be strictly in accordance with the order on the USBN9603 registers. USB device enumeration process, the system's USB connector to access a USB connection port (hub or host root hub), the device is turned on; the USB D + and D-data and the access of hub port or the host's root hub between two 15 K Ω with pull-up resistor. At this point, the pull-up resistor will make the data signal line-level rise, notice a new device access hub; then, use interrupt channel hub reported to host events, does have a new device access, the host device to connect the hub to send asks, so that the hub Set_Port_Feature to port USB hardware reset command sent and sustained 10ms, and then identify the device speed. At this point, the device has completed the initialization operation in the host that the device has left the reset State starting in the endpoint 0 is the default channel for USB control of transmission into the enumeration phase. Block transmission standard routine firmware send realizing through endpoint 1 routine to host block transfer function, the process shown in Figure 3. Upload ECG data, for example, firmware through the endpoint 0 receiving host upload ECG data requirements, data to be transferred into the buffer, at the same time, writePtr put the question to the transferred data, size, and other information into bulkState. Figure 3 transport send module routine firmware to receive routine through the endpoint 2 receive data from the host, the host should send a letter OUT to endpoint 2, SIE from the transceiver to automatically receive data and stored to FIFO2, FIFO2 automatically updates receive control register RXC State data receive hardware operation completes, the USBN9603 a reception interrupt transfer to perform S3C44B0X processor, firmware receives the interrupt service routine. USB communication protocol of the host-side implementation of WDM drivers including equipment feature drivers and bus drivers. Among them, the bus driver provided by Windows, this host-side software includes the following three levels: user-mode applications, achieve USB communication Win32API dynamic link library and kernel mode driver for WDM device capabilities. Dynamic link library encapsulates access kernel mode driver functions, and user application provides access to the interface, the user application simply call for specific data transfers instead of the host-side software design of the core is how to develop WDM device features driver. In Windows2000 platform installation Windows2000DDK, use VisualC + + 6.0 as a development tool, with DriverWorks Kit and kernel code debugging tool module, as well as USB SoftICE monitoring tool for WDM driver BusHound. According to the DriverWizard Wizard, select the device type is USB; select i/o request packet handling of IRP for IRP Queuing; create device interface is 128 bits of a globally unique identifier (GUID) that identifies that makes using CreateFile () function to open a device, WDM by GUID identification and access device driver; configuration control, BulkIN and BulkOUT these three endpoints transmit commands and data respectively. Configure three IOCTL-control command: MYUSB_IOCTL_COMMAND is host to send communications command control command, its IoctlCode as 0x812; MYUSB_IOCTL_BULK_READ and MYUSB_IOCTL_BULK_WRITE sent separately transmitted Bulk data read/write command, its IoctlCode 0x814 and 0x815 respectively. All Setup is finished, generate .inf Setup information file. In this framework, according to application requirements, you can write and host communication device firmware device drivers. When the host requires read and write in Bulk form and transmit ECG or blood pressure data, givesIOCTL_CODE as MYUSB_IOCTL_BULK_READ of IOCTLIRP, handling routine to BulkReadWrite (). By passing different parameters separately for BULK data read/write function, you first need to obtain from the IRP application delivery channel number, input/output buffer and its size and other parameters, call FindPipe () IRP request channel instance, constructed on that channel, called URB SubmitUrb () send realizing underlying URB, USB class drivers for the communication, the complete Bulk data transfer capabilities. Conclusion of this article to take full advantage of USB transfer speed, accuracy and ease of use and other features, the USB interface to household ECG, blood pressure monitor, complete the arm MCU and USB control chip interface hardware and software design, and ECG transmission experiment, indicating that the system has high reliability and accuracy. References: 1 Xiao-Wen .USB2.0 hardware design-Tsinghua University Press, 2002: 67 ~ 105 2 King arts. high-speed serial bus in DSP data acquisition system and research-Zhejiang University Master's thesis .2002: 9 ~ 21 3NationalCompany.USBN9603 (UniversalSerialBus) Full SpeedFunctionController.NationalSemiconductors 4 wu'an River, Lily .Windows device drivers (VxD and WDM) develop practice-electronic industry press, 2001: 120 ~ 177

Implantable cardioverter defibrillator principle and parameter settings

1 implantable cardioverter defibrillator (ICD) of the basic structure and function

The pulse generator and ICD electrode wires made up of two parts.

Pulse generator's main components including batteries, sensing and pacing lines and capacitors. The battery supplies the energy, the capacitor is charging, discharging, sensing and pacing line is responsible for ECG monitoring, identification of ventricular tachycardia (VT) and ventricular fibrillation (VF) and bradycardia, pacemaker pulse. Early electrode for epicardial electrode, chest after the installation, improved to subcutaneous electrodes, now progress to endocardial electrode by vein, allowing the embedding of greatly simplified. Lead on the one hand, the perception of signals incoming pulse generator, pacemaker signal delivery to the heart. Because of the electrode model, electric shocks through intravenous electrode and finish casing pulse generator or by intravenous endocardial electrode itself.

The basic functionality of ICD is to identify and deal with tachyarrhythmia and bradycardia, their identification and handling of bradycardia works and bradycardia pacemakers are the same.

Here only the identification and treatment of arrhythmia in principle.

1.1 quick arrhythmia recognition

To tachyarrhythmias of heart rate (or its corresponding circumference) and duration (or tachyarrhythmias of cycles) as a basic identification standards, and the initial recognition and identification, the initial identification of standards for each array tachyarrhythmias attack first, and then identify the standards used by the ICD therapy and unterminated tachyarrhythmias judgement.

VT and VF main distinction by frequency. Different manufacturers on the above identification standards of representation, such as the CPI company directly to frequency (times/min) and duration (s), and Medtronic company then the perimeter of the place of the frequency, the number of cardiac cycle that lasts. The following example shows how to identify ICD tachyarrhythmias.

If the recognition criteria set VT is 150 times per minute, and hoped that the VT attack duration is 10 s begin treatment when ICD.

If you use ICD-CPI company Ventak PRx Ⅲ, frequency standards can be directly set to 150 times per minute, the duration is set to 6 s, this is because the duration of the calculation is to meet the frequency standards to start. ICD continuous monitoring process that is, the heart rate of each heart girth and frequency identification standard week looks compare process, when ICD 10 consecutive echocardiography circumference there are eight in judgement is equal to or shorter than the recognition criteria perimeter (frequency standard 150 times per minute, the perimeter is 400 ms) that determine when ICD meet diagnostic criteria for VT and begin computing the duration. Obviously, the calculation of the duration before the tachycardia has lasted for at least 10 cardiac cycle, to the above 150/divided into recognition criteria, 10 4 heart period should as s, so although the duration set to 6 practical s and VT lasted 10 (4 + 6) s. The duration of the start, if 10 cardiac cycle has six meeting frequency identification standard and keep to the end of the duration (in the above example is 6 s), then at the end of the duration of the treatment program, otherwise required to meet the continuous 10 cardiac cycle there are eight in line with the calculation of frequency standards had just begun. Similarly, if you use the Medtronic company's Jewel series products, you need to set frequency standard is 400 ms, duration is 24 cardiac cycle (10 seconds should be 25 cardiac cycle, but is not programmable parameters 25 this value), if 24 cardiac cycle continuous meet the recognition criteria i.e. begin treatment procedures. This kind of ICD's frequency standards and duration are also met; that is, its duration is calculated starting with the CPI company different. About VF duration settings also illustrate. If VF frequency standard developed to 200 times/min, continuous 6 s start treatment, CPI product sets in the same way, i.e. frequency VT 200 times/min, the duration is 3 s (10 cardiac cycle time of occupancy is 3 s); Medtronic products have set the standards to frequency of 300 ms, duration 15/20. The latter means continuous 20 heart period (duration 6 s) 15 can meet the standards set by the frequency that reached the diagnosis of the circumference of the VF of diagnosis only heart rate and duration of the standard, and VT diagnosis in addition to these basic criteria, there is also a secondary standard for use with sinus tachycardia and atrial fibrillation-phase differential. Common ownership tachyarrhythmias of sudden (Onset.

VF diagnostic only heart rate and duration of the standard, and VT diagnosis in addition to these basic criteria, there is also a secondary standard for use with sinus tachycardia and atrial fibrillation-phase differential.

Common ownership tachyarrhythmias of sudden (Onset) and stability (Stability), there is the addition of ICD QRS Group wave width for the identification of VT and supraventricular tachycardia (SVT).

Paroxysmal tachycardia is started with the law of the circumference of the sinus rhythm interphase is relatively short, usually expressed as a percentage.

VT is a sudden outburst of, sinus tachycardia are generally occur gradually, gradually terminated. So the two can be used to identify emergency standards. Unexpected concrete set based on the patients tachycardia arises with the rule of law interval to determine, for example, each time with a heart rate law interval week duration by 25%, you can set its sudden is 20%. Once you have selected the sudden, at the same time meet the initial identification of standards of the heart rate, duration, and the sudden it meet the diagnostic criteria VT.

Stability means tachycardia differences between different Zhou's maximum allowable range, tachycardia, arrhythmia, regularity, usually expressed in milliseconds.

Atrial fibrillation is rapid heart rate, rhythm is not structured, and VT arrhythmia structured or only mildly uneven. Therefore, the identification of both can stability. IfWe observed that both the perimeter while to VT difference not exceeding 30 ms, stability is set to 40-50 ms. After selecting the stability criteria, you must also meet the initial identification of standards of the heart rate, duration and stability to meet the diagnostic criteria VT. If both SVT extra width using the QRS complex standards be differential.

1.2 tachyarrhythmias treat

Arrhythmia treatment with electric shock (Shock) and tachycardia pacing (Antitachycardia pacing, ATP) in two ways.

(1) electric shock: currently electric energy most programmable 0.1 to 34 J.

Product type specific parameter settings, there are certain differences, a small number of products the maximum electric energy of up to 42 j, the majority of products can be continuous shock 6 times. VF and VT can be used this way.

(2) ATP: there are two basic forms, i.e. short array pacing (Burst pacing) and perimeter decrements the pacing (Ramp pacing).

① nonsustained pacing is the same array pacing, perimeter equal and shorter than the tachycardia perimeter of pacing mode. Pacing the set number to perimeter tachycardia perimeter, usually expressed as a percentage of the cardiac cycle perimeter of 75% to 80% of set value, the termination of a higher success rate. Every pacing pulse number according to the treatment effect, pacemaker pulse too few are successful, too much is also not necessary, or even make arrhythmia acceleration. ② perimeter decrements the pacing is the same array pacing, girth gradually shortened pacing mode. This way, the termination of the success rate is higher than the short wave of rapid pacing, but enable arrhythmia accelerated opportunities, pacemaker pulse count more.

VF treatment can only use electric shock.

Generally speaking, the energy of the first electric shock than the test defibrillation threshold high 5 ~ 10 j, starting from the second biggest energy should be used. VT treatment can choose ATP and electric shocks. Electric energy from 0.1 ~ 34 j, generally a lower energy can be effective. ATP can set several programs, each program can choose two pacing mode, but can also be scanned. The so-called scanning refers to when an ATP is invalid, the next time the ATP's pacing perimeter or (and) the law interval automatically according to the set of values. Therefore, the treatment can be VT preferred ATP, invalid for low-power electric cardioversion, then invalid when high energy electric cardioversion of ladder treatment methods.

In addition, ICD is available storage in the electrocardiogram and tachycardia occurs, perimeter, with law interval, treatment time, manner and treatment response, information functions, for follow-up and reasonable adjustments to the diagnosis and treatment procedures.

ICD has electrophysiological function.

With this function you can induce ventricular tachycardia and test the effectiveness of the treatment program.

2 ICD work program settings

2.1 set workspace

According to the patients quickly arrhythmias and treatment set 2 ~ 3 workspace (1 x VF, 1 ~ 2 VT district).

2.2 set tachyarrhythmias of Diagnostics

(1) set each workspace frequency threshold: VF is 200 ~ 250 times/min, VT frequency threshold to clinical attack rate lower than 10 ~ 20 times/hours, two VT district of frequency of at least 20 times per minute.

Further recognition and initial recognition of the same frequency standard.

(2) set the VF and VT duration: VF's initial recognition duration to 3 ~ 5 s for the duration of the VT can be extended accordingly, but generally not more than 10 s; recognition of duration is shorter than the initial recognition.

(3) the sudden, stability criteria: likely sinus tachycardia are standard with sudden, atrial fibrillation history, plus stability standards.

2.3 set quick arrhythmia treatment procedures

(1) VF treatment procedures: VF electric cardioversion area only, the first electric energy ratio defibrillation threshold high 5 ~ 10 j, for security reasons starting from the second largest electric energy use, final 1 ~ 2 times to reverse the polarity of electric shock.

(2) VT treatment procedures: according to ATP-low-energy electric cardioversion-high energy electric cardioversion of ladder treatment settings.

Low frequency VT district can only set the ATP or combined with low energy to electric shocks, high frequency, speed zone can only electric cardioversion, can also be started using a perimeter decrements the pacing of the ATP program. 180/min following VT terminated with ATP's success rate is high, generally with a short array pacing, pacing perimeter from tachycardia perimeter of 80% of each array 4 ~ 10 pulse, sharp decline between 10 ms qualified the minimum perimeter is 200 ms, a total of 4 ~ 6 array. Perimeter decrements the pacing interval usually tachycardia perimeter of 90%, array, array may decline between 5 ~ 10 ms, pacemaker pulse can be fixed or may gradually increase, with lead times of four to six commonly used. Energy program at the ATP, the first energy to 1 ~ 10 J, the second increase of 5 ~ 10 j, the third largest energy available. ATP parameter and set the best of the electric energy to before or during electrophysiologic study results as it was.

2.4 settings on bradycardia pacemakers work parameters.

2.5 settings information stored job parameters (ECG storage power consumption more attention program control instrument tip).

2.6 considerations

① intraoperative measurement of defibrillation threshold, VF terminate the program number of lightning strikes should not be more than 2 times a second time selects the maximum energy.

2 invalid rows should be immediate, in-vitro defibrillation. ② I C D work parameters according to the follow-up of timely adjustments. ③ After each time the program control, verify that the print result set parameters noWrong.

Multifunctional microwave therapy instrument works and troubleshooting

Microwave multi-function treatment instrument use microwave radiation heating treatment, can achieve sterilization, and activating the role such as; the use of microwave in direct contact with focus enables the Organization to focus part of high temperature and solidification and cause vasoconstriction closed for therapeutic purposes.

Microwave multi-function treatment instrument equipped with different treatment for head, you can implement different treatment targets, which in anorectal branch, Gynecology, urology, ENT, dentistry, dermatology, Medical Department has a wide range of applications.

Microwave multi-function treatment instrument of many varieties are chooses wdz-c type.

Wdz-microwave multi-function treatment instrument of core circuit simple compact mainly consists of four parts.

1. microwave generator section.

Microwave generation by the magnetron, when its filament voltage (about 4.5V) and make it work under high pressure (about 1500V) have, that produces microwave magnetron. These two sets of voltage requirements for precision is not very high, by two transformer supplies.

2. power control section.

This part of the circuit is not complicated by an oscillation circuit with SCR (800V, 16A) to control the supply of high-voltage step-up transformer magnetron primary AC 220V's breakover angle to control the power output of a magnetron.

Third, time control section, this section contains two time control: preheating time control, time control.

1. Preheat time control circuit: warm-up time is about 3 ~ 5 minutes, control circuit consists of a "555" timebase circuit, through a triode 3DG130 control supply-voltage step-up transformer of magnetron primary side of 1st 6V relay to warm-up time without high pressure that is non-microwave output;

2. working time control from 0 ~ 99 minutes, reaching the alert after the scheduled time, manually RESET reset, this circuit integration time controller TIMER-JSS48A to complete

IV. other circuits, power adjust, power limit control, lifestyle, and power display parts.

1. power adjustment circuit includes a number of Rotary potentiometers and a Schmitt trigger 74LS74 composition changes through the potentiometer to control the Schmitt trigger oscillation output frequency to control to trigger the SCR BT33 final;

2, power limit control circuits, power limit signal taken from operational amplifier HA17324.

When continuous work manner, to the maximum output power: 150W, upper circuit through a triode 3DG130 triggered supply magnetron hypertension side step-up transformer primary second 6V relays to meet power Super no microwave output purposes. You must manually RESET Reset

3. working mode control by an micromove switch to select continuous or with foot pedal control work.

4. power display section of ± 5V power supply block by a pair of voltage: 7805, 7905 supply, circuit parts mainly by manifold LM34075.

5. microwave multi-function treatment instrument maintenance methods and considerations

(A), testing microwave output cord is short circuit or open circuit;

(Ii), testing microwave tube: find a wet soap, will output header inserted above, turn on automatic or manual to magnetron with filament voltage warming, crossed the control part to magnetron with normal-pressure, if, in the SOAP should be clearly heard the sound of burning;

(3), other control circuit is simple, you can reference the previous introduction to maintenance;

(4), notes: overhaul process, not the output is part of the near and alignment of the eyes or testes (no child left alone) is a good idea to make the output head on small tiehe, microwave output lines do not easily broken.

If the above method to do that you'll be able to fix it get, but considerations must not forget, do not outweigh the yo!

Laser treatment instrument touch screen interface design principles for analysis

Introduction

Along with the social improvement of the degree of automation, human-computer interaction capabilities needed major change toward a more convenient to use and more intuitive.

Laser treatment of the main applications of laser physics of the human body, the body's reaction to achieve the purpose of treating disease. Laser therapy apparatus as a precision instrument need precise control and dustproof, anti-static, moisture, etc. Laser therapy apparatus input devices with touch screen control, which is based on the above requirements from the user-friendly operation and interface intuitive perspective. Touch screen application allows for data display and data entry combination simplifies the entire device.

Principle 1 touch screen

Touchscreen attached to the monitor's surface, in conjunction with the monitor.

Simulation of electrical signals generated by touch, converted to a digital signal the microprocessor calculates the coordinates of the touch points, resulting in the operator's intention and implementation. Touch screen in its technical principle can be divided into five categories: vector pressure sensor type, resistive, capacitive, infrared-and surface acoustic wave, resistive touch screen in the practical application of the more used. Resistive touch screen consists of 4 layers of transparent thin Constitution, the following is the composition of glass or acrylic, top of the base is a layer of outer surface hardening treatment to smooth layer of plastic screen protector, attached to the upper and lower layer on the inner surface of two layers of conductive layer for metal (OTI, indium oxide), this two-tier consists of the small transparent insulation isolated points. When the finger touch screen, two conductive layer in contact with the touch point.

Touch-screen two metal conductive layers are used to measure the X axis and Y axis coordinates.

For the X-coordinate measurement of conductive layer from the left end leads to two electrodes, recorded as X + and X-. For the y coordinate measurement of conductive layer from the upper and lower ends leads to two electrodes, recorded as Y-Y + and. This is the four-wire resistive touch screen of the leader. When a pair of electrodes applied voltage, the electric conductive layer will form a uniform continuous voltage distribution. If in the x direction of the electrode to impose a certain voltage, while the Y direction of the electrode is not combined with voltage, the voltage at X parallel, contacts in the field of voltage values can Y + (or Y-) electrode reflected by measuring Y + electrode voltage to ground, we can know the size of the contacts and the X-coordinate value. Similarly, when Y electrode voltage, but on the plus X electrodes on top without voltage is measured X + electrode voltage, you can learn that the y-coordinate of the contacts. Measuring principle as shown in Figure 1.

Figure 1 4-wire touch screen measuring principle

Five-wire touch screen with 4 lines.

The main difference is that five-wire touch screen one of conductive layer of four are cited as four electrodes, a conductive layer only as a measure of conductor output x and Y to the measurement of voltage, the turn when in x and Y exert upward.

2 touch screen controller works

There are many touch screen controller, the main function is under the control of the microprocessor to touch-screen two directions when voltage, and the corresponding voltage signal to own A/D converter with SPI port, microprocessor provides synchronous clock of the digital signal into the microprocessor.

The basic structure of the controller ADS7846 is shown in Figure 2.

Figure 2 basic architecture ADS7846

Figure 1 touch point P Department measurement result is calculated as follows:

ADS7846 internal can register setting A/D converter of the resolution is set to 8-bit or 12-bit, in the present system of A/D converters, 12-bit resolution.

Then p dot binary output code to:

Of which:-added ADS7846 internal A/D converter on the reference voltage.

Touch screen controllers running through the serial data input DIN input control command control.

Control-command basic format:

Start sending commands specified bit7, high level valid.

A2: A0 is used to select data input channel, select the X-coordinate measurement 101, 001 select the Y-coordinate measurement. MODE to internal ADC resolution is defined as 8 bits (MODE = 1) or 12 bits (MODE = 0). SER/DFR for single/double-side reference voltage selection. PD1: PD0 according to power saving mode needs to select settings. These command control bit set will be part of the program code.

3 system hardware design

Laser therapy apparatus input system consists of three parts: touch screen, touch screen controller and micro-controller.

Microcontrollers Microchip PIC16F876 new chip company. Internal bus using Harvard double bus structure. In the same internal frequency, accelerates the data transmission speed to avoid a bottleneck. This chip thin RISC are easy to use, accelerate development speed. Internal program memory containing 8KB (paging operations), 256 bytes EEPROM, 368 bytes RAM and 8-channel ADC, 1 generic serial interface (SCI), 1 x I2C interface, 1 x serial peripheral interface (SPI), 3 timer and watchdog circuit (WathcDog) and many other important resources. Peripheral interfaces functional reuse makes the whole micro-controller is simple and powerful.

According to ADS7846 and micro-controller for data exchange interface features, choose PIC16F876 SPI port.

SPI port consists of three signals: SDO (serial data output)The SDI (serial data input), SCK (serial synchronous clock). Hardware connection relationship is shown in Figure 3.

Figure 3 diagram of the input system hardware interface

This article focuses on the laser treatment instrument input system design, and other hardware design only gives the meaning of the interface.

Due to the internal integration PIC16F876, so peripheral interface is quite simple, but to complete the complex control functions must conduct an internal register setting.

4 software design

In accordance with the above design ideas designed software applications.

Figure 4-based program with touch screen input detection part of the process flow chart. Among them, the coordinate data processing usually uses the lookup method, the coordinates of the user command, use the datasheet for the formation of coordinate information to transform fast quick reference tables, thereby enhancing the software run faster.

Figure 4 process flowchart

The following is the PIC16F876 with ADS7846 interface portion of the program code.

Conclusion

This system makes it easy and entered the peripherals are simplified in actual application improves the ability of human-computer interaction, received good social benefits.

System design ideas not only to applications in the medical industry, and can be applied to industrial production automation as well as handheld devices, and other industries.

Reference documents

1 Burr-Brown Corporation.

ADS7846 TOUCH-SCREEN CONTROLLER. 1999

2 Microchip Technology Inc. PIC16F87X Data Sheet.2001

3 Yu-yun, Wang Yi Wu Hung, a front.

PIC series MCU development application technology: electronic industrial press, 2000

Implantable medical electronics theory and design of power supply

0 prefaces

Implantable medical devices can be divided into two kinds of passive and active.

Most passive implantable medical device is a non-electronic products, such as contact lenses, cardiac stents, artificial heart valves, artificial joints and other organizational structures. Active implantation-equipment such as implantable cardiac subject quite and cardiac pacemakers and other incentive system, requires energy supply to replace or enhance the functionality of an organ, or treatment of a disease. Currently, implantable cardiac, except quite and pacemakers such device maintains the lives of millions of patients with heart disease. Other incentive system is also being used for the treatment of various types of problems as incontinence and diseases such as chronic pain, deep brain stimulation device is also used for the treatment of pain such as epilepsy, spastic-quite and diseases such as Parkinson's syndrome. Although these products are now the size of the application is not a big place, but certainly will in the near future for wider use. Table 1 lists some implanted electronic devices and their indications.

　　

Implantable medical electronic devices typically consists of two parts, namely, implanted part and part of in vitro measurement and control.

External part of the task in the body is the measurement and control of information in order to complete the diagnosis and treatment of disease. The entire unit including information acquisition, processing, archiving, control, command, display and record function. In vitro section and general medical instruments are the same, the system's features are mainly concentrated in the implantation of the section, as well as in vivo and in the exchange of information and energy. Implantable medical electrical equipment requires energy supply in order to work, its energy supply are implanted battery and an external power supply. This article combines specific implantable medical electronic devices in detail both the characteristics of the energy supply.

1, implanted battery

The use of implanted battery of important reason is because of its high reliability.

Unlike many consumer electronic products, for implantable medical device battery is not easily replaced. In implantable medical electronic devices before the battery is sealed securely in its interior. From this, in implantable medical electronic devices side on the stage, the storage phase and after the implantation of the human body, implanted battery has power for the device. Usually, we can determine the battery life. Then, as implantable medical electronic equipment part of implantable electric he qualified the implantable medical electronic equipment service life. Generally, implanted battery to work (5 ~ 10) years. During this period, implanted battery to have very small output voltage drop, without any adverse side effects. If medical technical progress allows the implantable medical electronic equipment replacement easier, you no longer need to consider the cell's own usage, this is only an ideal situation.

Doctors and patients want implantable medical electronic devices in volume as small as possible.

An implantable cardiac pacemaker volume about 20ml, implantable defibrillator volume about pacemaker mentioned (3 ~ 4) times. Either an implant type medical and electronic equipment, almost half of the volume occupied by internal battery. Therefore, volume energy density (energy volume ratio) or quality quality] [energy energy density than) implanted battery design choices are important to consider the parameters.

In order to avoid sharp edges and corners may damage the surrounding tissue or penetrate the skin, the majority of implantable medical electronic equipment shape is a circle or oval ring-shaped, implanted battery general design into a circle shape.

The shape of the battery can only be determined after the implantable medical device geometry.

1.1 early development of low-power or rarely high power usage of implantable medical devices, typically you can use the internal battery.

For example, implantation of cardiac pacemakers, battery power for cardiac stimulation in half, while the other half power to complete monitoring, data logging, the energy consumption is low. The implantable cardiac pacemaker of power, for example, the implantable cardiac pacemaker was originally used as a power rechargeable, through Inductive charging for energy delivery. There is a single battery voltage, capacity 190mAh 125v, the main problem is the battery life is short, the charging of reliability depends on the patient himself. Currently rechargeable power implantable cardiac pacemaker is no longer for sale.

In the 1960s, zinc and mercury batteries are widely used in implantable cardiac pacemaker.

This type of battery has a high charge volume density and stability of voltage, 3-6, zinc and mercury batteries in series provides voltage 4V ' SV. But this type of battery can not be done completely sealed and easy to make liquid permeability person caused a short circuit and the pacemaker. In addition, zinc and mercury batteries in the battery drain during voltage change is very small, so it is difficult to estimate the battery usage. There is no longer using the battery as the implantable cardiac pacemaker.

Radionuclide battery has also been used as the implantable cardiac pacemaker.

Radioactive element polonium has a half-life of 87 years, this element made of radionuclide battery in 10 years the output voltage drops only 1%. Radionuclide battery has a long service life, but bulky, poisonous, radioactive, and many other problems between limits its application.

1.2 lithium battery

In the mid-1970s successfully developed a lithium battery, the battery has a high energy density, high reliability, low self discharge as well as the application of solid electrolyte, sealed, override the zinc and mercury battery, the implantable pacemaker to extend the life span (5 ~ 10) years.

New titanium shell used to encapsulate the internal battery and circuit, from epoxy resin and silicone rubber padding. New titanium shell as well as special shielding from well protected internal objects, and reduce external electromagnetic interference. Install this new type of pacemaker patients can safely use microwave ovens and other household or Office within a common electrical appliances.

Currently, lithium-iodine batteries widely become implanted medical electronics energy choices.

Lithium-iodine battery is a solid state ion battery, the battery negative terminal anode is made of lithium, cathode that battery cathode consists of iodine and polymers such as polyethylene a 2 a vinyl compound adjoins the rebelsBetween the two levels is the solid electrolyte. Solid electrolyte for lithium iodide low conductivity will current limit in µA levels, but has enough drive cardiac pacemakers. Lithium iodide diaphragm can automatically healing, this makes lithium-iodine battery very safe and reliable is the implantable cardiac pacemaker-powered energy. Batteries and the control circuit engineering progress allows implanted battery only half the size of a previously. Since 1972, with approximately 50 million lithium-iodine batteries successfully applied to the implantable cardiac pacemaker. 1.3 internal rechargeable battery

Widely used in implantable medical electronic devices of rechargeable batteries have a nickel-cadmium batteries, nickel hydrogen batteries and lithium ion rechargeable battery (Li-ion battery).

Three battery part performance indicators refer to table 2.

Lithium ion rechargeable battery with its high voltage, high cycle life and high energy density, and other outstanding performance and attracts worldwide attention, is believed to be the current comprehensive performance best battery system.

Secondary lithium battery is a lithium metal (anode) to the cathode, to fit to the lithium lithium ion migration as electrolyte solution in order to have the channel structure of lithium-ion can easily be embedded, prolapse, prolapse, embedded in the structure of small material is the positive electrode (cathode) new battery system.

Currently. lithium secondary battery cathode materials have lithium cobalt oxide, lithium and nickel oxide and lithium lithium vanadium oxide, iron oxide, manganese oxide and lithium, different as-level materials secondary lithium batteries of different volume energy density, see table 3 below.

　　

Lithium cobalt oxide is this stage commercialization lithium-ion batteries in most successful cathode materials.

Currently, compared to other cathode materials, reversibility, LiCoO2 in discharge capacity, charging efficiency and voltage stability, best performance, but the price of lithium cobalt oxide is dearer, and pollution to the environment. Lithium nickel oxides of lithium cobalt compounds performance is similar, but because of its low price, it helps a lot. Lithium manganese oxide inexpensive, nontoxic and contamination of small, small impact on the environment. Lithium vanadium oxide with high capacity, particularly in recent years and developed the V2O3 gel, its energy density is far more than other materials, in substantial increase lithium-ion battery for use at the same time, due to its low cost, and no pollution to the environment, for a lot of promotion.

In short, different types of implantable medical electronic devices on battery requirements differ considerably, select implanted battery to be considered.

Such as implantable defibrillator, it can provide amplitude is greater than the pacemaker pulse amplitude 6 orders of magnitude of electrical impulses, but this situation is not frequent. Because the battery is not possible to produce electrical pulses, the sudden power prior to the release of the heart, the battery to the internal capacitor charging 20 seconds, the energy stored in the internal capacitor. During the charge, need 1A ~ ZA current. Lithium-iodine batteries can not provide large current, thus the implantable defibrillator generally use lithium batteries silver vanadium oxides. Some devices such as drug pumps it using electrochemical reactor to produce high pressure pump Chamber, which will inject the drug from storage room. Pump into the drug action is not continuous, regular actions or triggers by patients.

When the pump is opened several Ma current.

In this case, you can choose to have a low internal resistance of the battery, such as regulating thionyl chloride batteries, lithium fluoride carbon batteries, lithium, silver vanadium oxide battery, etc. 2 external power supply some implantable medical electronic devices can also be used portable external power supply, either through direct electrical connection or through a wireless RF connection. The article describes how wireless RF, wireless RF power diagram shown in Figure 1.

This power supply is an external battery-powered radio frequency oscillator

　　

Output after via RF power amplifiers to in vitro junior RF Induction coil, coil attached to the skin surface, implantation system of small parallel secondary Induction coil is placed under the surface coil and induction out r.f. voltage.

The RF voltage with rectifier, filter, regulator after stable DC voltage, or to the body charging the battery, or work directly supply the body electronic circuits.

In order to guarantee the implantable medical electronic devices of high reliability, use the external power supply are generally has a backup battery.

External device maintenance costs increased, because the wireless radio frequency interference and caused local tissue heating effect is not to be ignored. Nevertheless, for some implantable medical electronic devices, use the external power supply are still is the best choice.

Some implantable device volume very small to hold the battery.

As cochlear, it is the need for surgical implant replacement inner ear hair cells play a role of an electronic device. It's implanted part including implant and implant electrode, in vitro section includes a microphone, language processor, transmission cables, sensing coil, two parts. Power and data through emitting radio frequency range of electromagnetic waves.

Other implant device such as a left ventricular assist device LVAD) is a heart surgery machinery circulation devices, its main role is to lighten the load, lower left ventricular myocardial oxygen consumption, improving the diastolic pressure improve coronary perfusion, and increased cardiac output.

At present, the LVAD is clinically focused on helping cardiac surgery patients out of extracorporeal circulation and cardiac transplantation as transitional. LVAD by power, control system and pump components, control system and power is external, the pump can be built-in or external. Left ventricular assist device for electrical and pneumatic. Some electric implanted LVAD is equipped with a rechargeable battery, the external power supply to its charging. Generally the pneumatic LVAD of size is very small, the use of external rechargeable battery produce compressed air.

Use the external power supply mode for implantable medical electronic devices with high power continuously; use wireless RF connections, not only can achieve energy delivery, but also on implantable medical electronic devices for control and enquiries

Sought; in addition, implantable medical electronic equipment life and shelf life are no longer affected by the battery.

3 prospect

About implantable medical electronic devices of the energy supply continued to have exciting new breakthroughs and advances.

Rechargeable battery technology progress promoted by the body charging battery-powered by planting in the development of medical electronics devices; high energy density of lithium polymer battery and thin film cell has the potential to become future implanted battery preferred; use of other energy transformation in the body for energy supply (such as bio-fuel cells, the body temperature battery, use the organism itself mechanical energy as well as directly from Ann extraction power, and so on) have also been reported. In short, to a more secure, long-term supply of energy, without external radiation intensity energy (wave or near-infrared) of energy supply, will be implanted medical electronic devices development direction of the power supply.

Rehabilitation based on-chip design and application of methods

1. introduction

Human balance is able to carry out all kinds of Sports Foundation, standing, day, walking all need balance.

Once the balance has the disorder, the person's ability to act on the unconstrained, to study, life a great deal of inconvenience. In modern societies, demographic ageing, the elderly due to a disease causing brain damage caused by the reduced ability to balance, operational capabilities. Therefore, clinical treatment, need a function to the balance of the device. Our school in collaboration with shanghairuijinyiyuan, analyzed the domestic and international, on the basis of relevant information, using advanced computer control technology developed a multifunctional body balance rehabilitation equipment. The use of the instrument can be objective, quantitative and balancing test, analysis and training, and balance of static tests and dynamic training. As clinical research provides effective means.

2. instrument features

· Instruments for measuring range: 10---360kg · focus location: ± 1.0mm · power supply 220V AC · instrument provides the weight distribution maps, displacement maps, balance, radar, gravity spectrogram for quantitative analysis of body balance ability. · instrument for static open eyes and the eyes of two States of gravity track testing. available · devices body balance ability of dynamic testing and training.

3. scale rehabilitation equipment design principles

Balance rehabilitation instrument is measured as the focus of the human figure, motion and gravity trajectory analysis in order to get the map of body balance ability in a series of data.

The focus of an object is the object of the section of the joint force of gravity, and the role of the body's Center of gravity is the body parts of forces of gravity. Human stand, will inevitably there is a slight swing and sway, while parts of the body of any activity that will cause the change of body Center of gravity position, so these minor swing and sway will cause the body's centre of gravity location changes. This kind of centre of gravity location changes, and reflects the human body swaying and the extent and pattern of swing, is the study of body balance important functional status.

Accordingly, in balancing the rehabilitation, we use gravity strain and monolithic a gravity test platform, the focus of the human body to stand for real-time measurement of the motion path will be measured gravity trajectory data via RS-232 serial interface to the host computer, gravity test platform test 30 per second personal weight heart moving track data.

In the host computer, use VISUAL BASIC Visual language programming, the gravity test platform of gravity trajectory data calculation, analysis, draw the human body weight exercise dynamic track map, weight distribution, displacement map, radar spectrum, balanced Center of gravity and the parameters that can be divided into open and closed eyes two ways to test the body's Center of gravity trajectory. Clinicians through graphics and parameter table of observation, analysis, can be judged against the illness and treatment.

In order to help balance disorder patients recover balance capacity, the capacity of patients with balance training.

Rehabilitation in balance Analyzer, we use VISUAL BASIC Visual language as well as multimedia technology, design a dynamic equilibrium training program. In the program, use of language, music and animated graphics, so that patients in the pleasant and easy virtual environment balance training and can ability to select patients with balance for your training intensity manner balancing ability of rehabilitation. Clinicians can also select the appropriate scenario, the ability to make balance in patients with rehabilitation and therapy, or balance of a dynamic test.

Rehabilitation in balance Analyzer, gravity trajectory measurement is key to the instrument.

In order for the test and validation platform easy to use, we use a microcontroller for gravity trajectory measurement in real time, using the PC for data processing and generating the necessary graphics.

4. rehabilitation of structure

4.1 rehabilitation apparatus structure diagram

Figure, gravity sensor 1-6 is the model for the weight sensor NEA-60kg, they are installed in the second test platform of three corners, for measuring the body's Center of gravity of the motion parameters.

Gravity sensor output signal is connected with single-chip, chip by 30 times per second sampling speed measured body weight exercise dynamic trajectory, and through RS-232 serial port the data transfer to PC computer. In the computer to measurement data processing, and generate the corresponding image display, also can be documented through the printer.

4.2 test platform

There are two test platform, each an equilateral triangle by 45 cm thick plate 5mm and three gravity sensor.

Three sensors evenly in the testing platform of the three top corners, each sensor measuring range of 0-60 Kg. The average person's weight in 100Kg following, taking into account the impact of the human body to stand up, we design test platform load 0-180Kg, therefore two test platform, the total load is 360Kg. After the test, the test platform fully able to bear, and, in each test platform gravity sensor edge installed anti overload devices.

4.3 gravity trajectory measurement instrument

Measuring instrument selection and MCS CPU chips compatible AT89C52, internal strip 8K bytes Flash can re-writable 1000 times, data is kept for 10 years.

The single-chip low power consumption, easy to modify the program. Responsible for data collection and transmission of real-time. Sensor measurement signal transmitted to transform into a frequency signal through AT89C52 MCU T0-input, high measurement accuracy, ease of photoelectric isolation, strong anti-interference ability. Gravity trajectory sampling through mechanics torque balance theory to implementation. Instrument at the measurement platform three corners, three uniform distributionA force sensor. People stood in the measurement platforms, the body's weight by measuring platforms to force sensor. Single-chip continuously detect sensor output signals, and through the torque balance principle for mechanical calculation, seeking out the trajectory of motion of body Center of gravity, the measurement accuracy of ± 0.1kg SCM acquisition of gravity trajectory data, via RS-232 serial port receives a MAX-232 chip, and through MAX-232 chip and PC Exchange information, complete body Center of gravity trajectory measurement work in real time.

4.4 data processing and image generation system

A PC computer, on a Windows platform, use Visual Basic's serial port programming function reads the data transmitted to SCM.

Data processing, forming a center of gravity map, displacement map, balance, radar, gravity spectrogram, parameters, and other four-figure table information.

In human-computer interaction, logon test ' information, including name, patient number, height, weight, age, gender and other information, and there are language, music, background images and other multimedia be aided.

Visual Basic or VB is a visual language, in the Windows environment of language development tools.

In the application development process, in particular the graphics processing do not have to write code to describe interface elements look and location, as long as the pre-established object onto the point on the screen. In a VB environment, use of event-driven programming mechanisms, innovative and easy-to-use Visual design tools, use the Windows internal application programming interface (API) function, as well as the dynamic link library (DLL), dynamic data exchange (DDE), object linking and embedding (OLE) open database access (ODBC), and other technologies, you can efficiently and quickly developed a Windows environment with powerful, graphical interface rich application software system.

5. project prospect

International application already exists on your computer for body balance ability tests and analysis of, the domestic development of individual units have static balancing instrument.

We developed the body balance rehabilitation apparatus, is drawing on the existing balance of benefits on the basis of a full understanding of the clinical diagnosis requires shanghairuijinyiyuan, developed a test with static and dynamic balance training dual function rehabilitation equipment. In static testing contains more parameters, dynamic training, rehabilitation training content, also including clinical studies section. The instrument can be used as a clinical treatment can also be used for clinical studies, have wide application.

As China's ageing population growth and the development of modern life, the body balance capacity of disease is increasing,

In this area of research and treatment demand is growing.

Import of the equipment is expensive, each instrument in tens of meters, and you do not have localization features, use very inconvenient or difficult to carry out two development. And our own manufacture of equipment, functions better than imports, prices for imported only shijiwanyuan, one-third to one quarter of the instrument, but also facilitate two development. With Medicare coverage and focus on health, on body balance rehabilitation for this type of medical device requirements, there will be a larger development, but also the low price of the instrument easier to enter the community hospital. We believe that balance rehabilitation apparatus will in clinical treatment and clinical studies for a wide range of applications, to contribute to human health, to improve the quality of human life.

Reference documents

1. National computerized body balance Tester application Conference compilations Shanghai rehabilitation medicine neurological rehabilitation Professional Committee 1997 2. Fan Yi of Visual Basic and RS232 serial communication control youth publishing house 2000, 8 3. Changjian's experience health detection and conversion technology machinery industry press 2002, 3 4 Cao Bo Rong, principle and application of single-chip technology China Civil Aviation press 2003, 7 5. Automatic detection of equine belt and other technical machinery industry press 2000, 5 6. Lee Chaoqing PC and microcontroller data communication technology space University Press 2000, 12

Fuzzy control of portable ECG monitor design

　　

At present, the acquisition of ECG, analysis and diagnosis of ECG monitoring system has been widely used for heart diseases prevention, diagnosis and played a significant role.

But this type of ECG monitor can only be in the patient or the patient to static special circumstances to use, the heart that is too high, especially heart disease suspected patients and early heart disease, affecting their normal working life; and the other portable ECG monitor, its 24-hour can monitor, but its storage needs lots of space for ECG playback requires a significant amount of time, in the light of the above two questions, this article design based on fuzzy control of portable ECG monitor. He overcome these two problems at the same time also a breakthrough in the past, online diagnosis disease of single-value processing, can more accurately determine the abnormal ECG and achieve a timely issued an alert. 1 system President design 1.1 system design goals according to the ECG signal characteristics, biological signal processing system and the development of modern ECG monitoring technology, this system using high-speed SOC series MCU C8051F020 as cardiac monitor's main chip implements the following features: (1) measurement with non-invasive, security, accuracy, repeatability strong, etc.; (2), measurement of simple and convenient operation, without prejudice to the question monitoring patients a normal life; (3) real time analysis ECG and judge the signal is, exception, preliminary monitoring patients diagnosed disorders of the heart; (4) 16 MB of FLASH memory to store the users 24 hours of abnormal signals; and (5) system error alarm function; (6) can be stored in abnormal ECG via the USB interface to the PC for further diagnostic ECG. 1.2 system hardware composing the system hardware diagram shown in Figure 1. First of all from the electrode circuit acquisition of the measured object Dim ECG, then to zoom in on the signal, after a filter directly to the main control chip, the other into the lead off detection circuit, then the connection with main control chip C8051F020. Signal after entering master chip C8051F020, appropriate treatment, alarm, storage, transmission, etc., judgment. 1.3 system flowchart system flowchart shown in Figure 2. 2 fuzzy analysis ECG automatically control section's main goal is to make the diagnosis of cardiac arrhythmia. The clinic for cardiac arrhythmia automatic diagnosis is combined with rhythm analysis and waveform shape analysis of measured ECG waveform recognition classification and diagnosis according to predetermined standards or criteria to make the appropriate clinical diagnosis. But the design is based on the extraction of characteristic value combination of medical knowledge and medical expert system completes the judgment. First of all, according to the following criteria for the treatment of patients with initial detection diagnosis: tachycardia r-r interval < 0.5 s (120 times/min); bradycardia r-r interval > 1.5 s (40th/min); arrest and ventricular fibrillation in a long time no QRS, generally this time > 1.6 s; leakage Bo a r-r interval is about the average r-r interval before 2 times after and no one beats is checked out as leakage Bo, r-r interval greater than the average of 2 times but less than 1.5 s, as room sinus stop checkout; ventricular premature ventricular contractions in pairs (two consecutive ventricular extrasystole): room for 2 with LV (normal and ventricular premature alternating twice over); Chamber of triple law (normal, normal and ventricular premature alternating two consecutive times above), are classified as premature ventricular contractions. Testing standard complex, the need for further analysis using fuzzy logic; judgment in T R (R on T) this is in the Ventricular Repolarization era (T-wave) appears in PVC, because T wave cannot detect, so only by rhythm analysis; insert premature is no compensation of the beats, the beats of roughly equal beats R-R interval before average R-R interval; atrial premature beats (APB) an adaptation of a premature ventricular contraction. More on heart disease is the criterion for judging the second value, this method of detecting simple easy-to-implement but on diseases of the judgment is not accurate. In fact there are a large number of medical diagnosis using fuzzy judging language and behavior, according to the prevalence in patients with multiple parameters multiple value judgment. These criteria are thus aspects of medical experts of prior knowledge, use these criteria to form multiple fuzzy rule, the medical expert clinical diagnosis disease with machines. Here's to fuzzy logic testing room of early Bo, for example, to monitor the patient's condition to conduct preliminary diagnosis, and the difference is, abnormal ECG, abnormal ECG recording only. In single-chip implementation of fuzzy control generally use 3 ways: direct transfer method, the strength of the look-up table and the formula calculation. Considering the direct consulting by offline calculation, get a fuzzy control table control table stored in computer memory, the application in the control, the speed while soon but if variables more (this system with up to five) will result in the dimensionality of fuzzy control, with high storage table lookup is not convenient. With the pretended formula also small for this system parameter calculation. While the transfer mode is based on the strength of fuzzy control of a minimal approach to inference. Each input parameter is mapped to more than one membership grade, each input activates the rules that may correspond to different results. Used by various small principle calculation corresponds to the output of the combined strength of the rule, and then press the largest membership principles that corresponds to the credibility of the conclusions. Thus, for each input can be obtained with the conclusions of the corresponding output intensity. Known as the output of membership. Get maximum output intensity of the membership as output. Experimental results show that this method most appropriate to this system. Here's a case study with beats that extract r-wave width (RW), RR interval (RR), the R wave area (RA) T wave area (TA), the T wave value (TH) these five eigenvalue diagnosis using fuzzy to be custodians of ventricular contractions occur. Some fuzzy rules table as shown in table 1. 2.1 membership function stored as single-chip memory capacity is limited, ifThe system input and output on the domain of all membership functions of continuous curve for storage, it is not possible, so this system for triangle membership function takes three-point method and storage 3 vertices of a triangle; and a half for the two sides of the waist and trapezoidal storage top 3 points. Membership function stored in ROM, Figure 3 to R wave's width description for an example. 2.2 input characteristics of fuzz extraction is the exact values, the parameter will they be compared with the membership function, find the appropriate amount of fuzzy input of membership in the range 0 to 1, the microcontroller can be said to 00 ~ FFH. For the purposes of this system, each accurate input value corresponds to a maximum of only two fuzzy input quantity is greater than zero, the remaining amount is fuzzy input to zero. For example: suppose RW = 1.1, from table 3 that he fell in (m) and large (L) two interval, in (m) and large (L) of membership: μ M (1.1) = (1.3-1.1)/(1.3-1.0) × FFH = 5 μ H A L (1.1) = (1.1-1.0)/(1.3-1.0) × FFH = 55H in RAM to open up an area, enter the depositing the fuzzy. 2.3 fuzzy rules deposited fuzzy rule expressed as: IF A and B and C and D and ETHEN Y (or Z) which "IF" immediately followed by the word says, "until THEN" after the word that follows. First of all the values the input of fuzzy S, M, L, XL, respectively, and the numbers 0, 1, 2, 3, namely: RW, RR, RA, TA, TH: S = 0, M = 1, 2, L = XL = 3. Each rule uses 3 bytes. 1 byte 4 bits high 1 front pieces of fuzzy values, low 4 bits 2 fuzzy values before parts; the first 2 bytes of the high 4 bits before 3, low 4 bits before 4; 3 byte 4 bits represent the high 5 front pieces, low 4 bits after the pieces. Where F represents the first piece, A representation is PVC, "B" may be PVC. As a rule (stored in ROM), for example, as shown in illustration. 2.4 fuzzy reasoning for each set of input data, first to blur and then iterates through every piece of fuzzy rules, take the first rule first pieces (3H) as an address offset, coupled with the fuzzy input in RAM RW deposited first address (40H), you can store from RAM RR in the zone to find out the membership grade A1 XL; take the first rule of the second front piece (3H) as an address offset, coupled with the fuzzy input in RAM RW deposited first address (44H), you can be kept from within the RW RAM area to find out the membership Grade B1 XL; and so on have membership C1, D1, E1. According to the intensity of transfer method, take the A1, B1, C1, D1, E1 in minimum value as the rules for the language variable "PVC" Y1 of membership. When all rules are: after traversal "PVC" membership Y1, Y2 ~ Ym, "may be PVC" membership Z1, Z2-Zn Y1, Y2 ~ by Ym's maximum value as the "PVC" membership Y, Z1, Z2-Zn maximum PVC as "might be" membership Z. If Y <7FH且Z<1FH,则输出"正常";如果Y>Z,输出"是PVC";如果Z> Y, output may be PVC.

3 conclusion this design of ECG monitor, set ECG collection, analysis, and the system volume is small, secure, reliable, and can not be custodians of the normal life of use, you can diagnose the illness, thereby initially save storage space, saving the time to further diagnose the illness, the experiment yielded very good results.

If you are able to combine more the aspect of medical experts of knowledge, you can achieve better diagnostic capabilities.