High-performance, low-saturated linear regulator (LDO) development

The whole equipment continuously miniaturise and provincial electricity, power consumption, small low dropout linear regulator (LDO) is becoming a switching power supply with linear regulator market mainstream. In order to achieve high performance and high speed, internal use of micro-computer or digital signal processor (DSP) technology has advanced by leaps and bounds every year in progress and development, at the same time, these micro-computers or digital signal processor essential power supply voltage is lower and lower. In addition, different manufacturing process corresponds to the voltage of the respective differences, and therefore requires a wide range of power supply voltage. To resolve this problem, the manufacturer started in the Middle voltage switching power supply setting, use LDO regulator with LSI power of new technologies. On the other hand, in the battery device also uses a large current LDO regulator in order to maximize the efficient use of battery voltage.

Use the DC/DC converter from obtaining high input power voltage 5V or so, and then use the linear regulator buck into 3.3 ~ 1.0V voltage, which is the usual power structure.

Such regulators are called subordinate linear regulators, in need of such a power structure to the device near a low input voltage supply more stable power supply. ROHM developed BD □ □ KA5 series product is suitable as a secondary linear regulators (Figure 1).

Secondary voltage regulator is seeking to further save space and more secure at the same time, constantly improve it in order to adapt to the DSP components such as narrow input voltage range and the high accuracy of must.

BD □ □ KA5 series 500mA current capacity while only, but the output phase compensation capacitor can support 1 μ F small ceramic capacitors, saves the space taken by regulators. At the same time, through the use of ROHM proprietary trimming techniques, the output voltage accuracy improves ± 1%. In addition, through the use of P-Channel MOS transistors as driven output transistors, even if you increase the load current to control circuit current and thermal design. Power supply input range is the most suitable 2.3V-5V 3.3V, 5V power supply input range. In addition, the output voltage specifications including 1.0V, 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, adjustable input type and low voltage output, etc., products to meet different needs.

On the other hand, from battery direct gets output voltage standard fixed output and adjustable output remains essential, its peak output current of increasing every year.

ROHM's BA □ □ DD0 series is to have the current capability of LDO 2A (Figure 2). The series of achieving high output current of 2A, the output voltage accuracy improves ± 1%, and low-voltage 0.5V. Corresponding input voltage changes, avoiding the output voltage is lowered to low input voltage limit, ensures low voltage output started. In addition, the industry-standard pin configurations 78 series and ROHM previous 1A low saturation voltage regulator-compatible, easy replacement. Input voltage range (3 ~ 25V), output voltage range is from 1.5V, 1.8V, 2.5V, 3.0V, 3.3V, 5.0V, 9.0V, 12V to 16V.

Equipment in order to reduce power consumption without working part, in each region cut off the power of power management.

BD □ □ KA5 series and BA □ □ DD0 series of all models, all with under external logical interrupt all lines of shutdown switch function, the standby current consumption 0 μ A (typical), in favor of a low-power design.

These two series LDO regulator products have built-in protection circuits are as follows:

1. overcurrent protection circuit.

The use of automatic fall-protection circuit. If the overcurrent protection circuit starts to work, the output voltage drops, more focused output current, and hanging-type protection circuit can be compared, is short circuit, exception state chip heat consumption control in 1/3 ~ 1/5 (see Figure 3).

2. temperature protection circuit.

Temperature protection circuitry on the chip temperature exceeds Tj = 150 ° c automatically stops the output and to prevent overheating and damage caused by the chip, so as to achieve the purpose of the protection of the chip. If the chip temperature drop, you have to recover the hysteresis width output (Figure 4).

3. the overvoltage protection circuit.

Overvoltage protection circuit is built-in in BA □ □ DD0 series products, if the output appear above 25V, surge protection circuit starts to improve chip components pressure resistance, even if the input voltage exceeds the 50V, is also able to prevent chip damage (Figure 5).

4. high static pressure.

Output of electrostatic discharge pressure for human body model, you can achieve more than 6KV, in any environment with a high reliability.

Infrared body thermometer circuits design

Because medical needs, in many cases, normal thermometers have satisfied a fast and accurate temperature measurement requirements, such as the station and airport, population density and a great place for the measurement of body temperature. Although now abroad this temperature measurement technology is more mature, but internally the technology is still in development stage. Therefore, in order to adapt to the needs of medical development, effective special environment temperature measurement, thereby effectively control and prevention, such as SARS, special spread that there is an urgent need to design a temperature measurement speed and accuracy of the thermometer. For general industrial use of infrared thermometer accuracy is not high enough, according to this principle of infrared temperature measuring, through key device choice, aiming system design, and temperature compensation automatically adjusted to improve the accuracy of the infrared thermometer, designed an infrared temperature measurement circuit for the personnel-intensive and the flow is large fora rapid body temperature measurement. 1 infrared temperature measurement principle of nature all temperature is higher than absolute zero (-273.15 ℃) objects, as molecular thermal motion of all keep the surrounding space radiation including infrared band, electromagnetic waves, its radiation energy density and the temperature of the object itself between radiation law. Group-radiation-radiation law principles: type: E-radiation emitting ° W/m3; σ to Stephen-Boltzmann constant, 5.67 × 10-8W/(m2 · K4); ε is an object's radiance; t is the temperature of a body, K; T0 to objects surrounding environment temperature, K units. Measurement of the emission of E, can reach the temperature. Use of this principle of temperature measuring instruments called infrared temperature meter. This measurement does not need to contact the measured object, therefore belongs to the non-contact measurement. Infrared temperature meter measuring range is very wide, ranging from-50 ° c up to more than 3 000 ° c. In different temperature ranges, object of the wavelength of electromagnetic energy distribution, at room temperature (0 ~ 100 ° c) range, the energy is concentrated mainly in the mid infrared and far infrared wavelengths. For different temperature ranges and for different measuring object, its specific design. According to the type (1) principle, instrument measured by infrared radiation:-: A for optical constants, and the specific design of structural instruments; ε 1 to be logging object of radiation rate; ε 2 for infrared thermometers of the radiation rate; T1 to the measured object's temperature (K); T2 for infrared thermometers for temperature (K); he is represented by a built-in temperature detection components measured. Emissivity ε is the one used to express the capacity of the emitted wave coefficient, a scale from 0 to 1.0. The best radiation is the radiation rate 1.0 objects, physically called blackbody. This is a theoretical concept, in fact, there is no object of the radiation rate can reach 1.0. But can produce extremely close to the actual ε = 1.0 blackbody calibration for thermometer. All real objects, including all parts of the body surface, its value is a ε below 1.0 values. As ε value extremely difficult to measure but not sure, the meter measured E, press-(2) calculated T1 there will be errors. In practice, the instrument is in ε = 1.0 blackbody calibration on a good factory, measurement of ε = 1, its indication that the object represents the object's actual temperature, if the object does not equal 1 ε, meter readings do not represent the actual temperature, the object should be amended. Radiation wavelength in the human body primarily 9 ~ 10 μm infrared, through the body's own radiation measurement of infrared energy, will be able to accurately measure the surface temperature of the human body. Because the wavelength range of the light is not absorbed by the air, thus the use of human radiation infrared energy to precisely measure the surface temperature of the human body. The body of the infrared radiation and he's surface temperature has a very close relationship, therefore, through the body's own radiation measurement of infrared energy, will be able to accurately measure the surface temperature of the human body. Infrared temperature measurement technique by the biggest advantage is the test speed, 1 s within the test is complete. Since he only receive human foreign emission of infrared radiation, no other physical and chemical factors on the human body, the human body without any harm. 2 structure diagrams and circuit design 2.1 structure diagram design as shown in Figure 1 as a design system architecture diagram. 2.2 temperature sensor for temperature measurement device using the infrared sensor, he is able to receive objects emitting infrared and converted into a voltage signal. I use a unit of Pyroelectric sensor PM611, this sensor is single-sensitive element, because he uses a receiver element and two parallel compensation element threaded structure, it can also be effective compensation environment temperature fluctuations, the effect of vibration is disturbing. He's working temperature is-20 ~ + 70 ° c, especially suitable for measuring body temperature. And the index are PM611, so use his temperature meter probe. As shown in Figure 3: the sensor D, S, E, respectively, and the markup in the circuit diagram D, S, E connection. 2.3 measurement circuit for measuring circuit shown in Figure 4. 2.4 integral circuits in the analog signal into a digital signal, select the ICL7106 integral-type A/D converter. He mainly has the following advantages: the integral-type A/D Converter Convert high precision, low cost; his precision and integral resistance, capacitance of precision-independent integral, it can reduce the quality of the components; requested against the interference ability; his peripheral circuit is simple. However, there are also some disadvantages ICL7106: baseline power changes directly affect conversion accuracy, when chip voltage reference within the General temperature influence is relatively large, when accuracy is high, you should use an external reference voltage source; the working speed is low, generally 1 ~ 20/s. So the main features of the integrated ICL7106, especially in order to improve the precision, the design uses an external reference voltage source. In addition, because for fastest measurement speed is 1/s, ICL7106 work speed lower disadvantage on our design has no effect, but his advantage is well suited to the needs of design, A/D ICL7106 is converted. 2.5 LCD display shows part of the circuit by many liquidCrystal display drive ICL7106 and standard-LCD EDS801 and other components. 3 debugging in the experiment by regulating A1 output 10 k Ω rheostat for A3 size of the output signal is changed, when A3 output less than 2.0 V, you can adapt ICL7106 quantum 2.0 V work characteristics, therefore two A3 potentiometer to adjust the size of the A3 output, make sure that when the temperature does not exceed 2.0 V. Debugging, using a known temperature (20 to 70 ° c) before the object is placed in the probes, regulating ICL7106 section of R12, LCD display the correct temperature, and a known temperature, continue to adjust the potentiometer, the displayed value is equal to a known temperature value accurately and repeatedly adjusted several times. Note do not exceed PM611 sensor and ICL7106 D A/Integrator temperature limit.

Measuring multiple physiological parameters of the wireless terminal medical monitoring system

Multi-parameter monitor is important in clinical nursing unit, it can monitor the patient ECG, blood pressure, oxygen saturation, pulse rate, respiratory rate and temperature, and other physiological parameters. At present, domestic universal use with CRT or LCD displays have a portable monitor, this instrument is capable of performing real-time data and waveform display and operations more flexible, so it is used primarily to help doctors diagnose and analyze the patient's condition. However, due to its large, power consumption is high (add 220V AC or built-in current), it is not easy for patients to carry, even cannot simultaneously on multiple patients care. This article is designed for wireless distributed medical monitoring system will leave no stone unturned to compensate for the inadequate. The system with three separate OEM modules for measuring physiological parameters, each module separately and a wireless transceiver function control display module connected to constitute a separate device, so each module in a significant reduction of power consumption, which are correspondingly reduced. Patients can choose according to the different needs of different modules, each module on the LCD screen can be displayed measurement signal correctly. All of these modules with PC for wireless information exchange, PC can give each module registers a unique serial number, and you can access the information for each module, the information store, analysis, display, press q, etc, this is easily achieved many modules extend that to achieve this more real-time monitoring of patients. 1 system structure and working principle of the system is mainly composed of hardware and software, two-part. Hardware including PC and three independent modules that the module ECG module, oxygen and blood pressure modules, each of these three modules are controlled by the OEM module and show transmission modules. ECG module mainly used to measure ECG, respiration rate, body temperature, and other parameters; oxygen module mainly used to measure the blood oxygen saturation and pulse rate, and other parameters; oxygen module mainly used to measure oxygen saturation and pulse rate, and other parameters; blood pressure module used to measure blood pressure parameters. Software parts mainly PC central monitoring software, including databases and user interfaces. Figure 1 is a wireless terminal medical monitoring system structure diagram. Figure 1, the OEM module and PC through wireless transmission module for serial port communications to exchange information. The OEM module acquisition of data on PC for processing after being stored. Users can be in central monitoring software interface, select any of the modules view real-time acquisition to data or waveform, software can automatically analysed the data, unusual alarm signal in a timely manner. 2 the module functions and features 2.1 control displays the transfer module control displays the transfer module to Atmega161 microcontroller core, an external graphic LCD module WGM-12864, press and NRF903 wireless transceiver modules. Its circuit structure as shown in Figure 2. Atmega161 is Atmel company produced a low-power CMOS 8-bit single chip RISC, its performance 1MIPS/MHz, 16K bytes of FLASH, 512 bytes of EEPROM, 1K bytes of memory, 35 common i/o port, 32 universal working registers, three timers, internal and external interrupt sources, two programmable SPI port UART, and three by the software-selected power-saving mode. WGM-12864B module is a monochrome graphic dot matrix LCD display module, dot-matrix is 64 x 128. Its 8-bit data line and the mouths of PA Atmega161, D/I indicates that the data bus on the number of signals is dot-matrix or control command words, R/W indicates that the current operation is a read or write operation, E is the control-side, RST is reset client, CS1, CS2 was around lattice district elections end. PC1, PC2, PB1, PB0 to function keys and LCD together to form the menu style of human-computer interaction interface, control the corresponding OEM module. In work mode LCD displays from OEM module Gets the information of related data. NRF903 module is a wireless transceiver modules. NRF903 is a NORDIC company launched single-chip wireless transmit/receive one chip that uses Bluetooth (Bluetooth) core technology and design, a 32 foot chip includes a three-stage high frequency emission, high-frequency receiver, PLL synthesizer, I/Q modulator, I/Q demodulator, multiple channel switching, asynchronous communication interface, its programming interface CFG_CLK (configuration registers clock), CFG_DATA (configuration registers data), CS (configuration registers pieces selected) and SPI port Atmega161 PB7 (SCK), PB5 (MOSI), PB4 (SS) connected to the operating frequency, channel, output power and output clock frequency and other parameters to program settings. Set CS to high level, from 14-bit microcomputer control word in each CFG_CLK programming mode clock signal rising edge, CFG_DATA end logical value written to the configuration register, the programming information is loaded, the parameter is set to complete. STBY, Atmega161 PWR_DWN respectively and PD6, of, you can set PD5 as a standby or power-down mode. Data interface for DATA and a UART1 mouth Atmega161, used to receive and send data. TXEN feet and connected to PD7, used to control the sending and receiving of data. 2.2 ECG OEM module ECG OEM module adopts Beijing multran Tong Yuan electronic instrument co., Ltd of BT007 seven channel ECG strips. BT007 to automatically measure the human heart radio, respiration, heart rate, respiration, etc, body temperature, and other parameters, has the following characteristics: synchronization seven channel heart radio, four programmable gain, three-level filtering mode (diagnostic mode, guardianship, surgery), Bo pulse suppression feature, leads off the alarm, heart rate range 20-250BPM, defibrillation and electric knife interference, impedance respiration, respiratory rate range: 5-99BPM; dual temperature measuring, measuring range 0-50 ℃, the display precision 0.1 ℃, measurement accuracy 0.2 ℃. Communication with the user interface and UART serial port, there are two communication protocols: synchronize three-channel synchronous ECG Protocol and seven passChannel ECG Protocol, you can choose via jumper. Synchronize three-channel ECG Protocol features: 19200 baud, 8 data bits, 1 start bit, stop bit, no parity bit; synchronization seven channel ECG Protocol features: 28800 baud, 8 data bits, 1 start bit, stop bit, no parity. You can send to the MCU control word for the module, control the gain, filtering mode ECG; ECG plate data sent to the MCU to 1 byte header and a number of bytes of data as a group, the group header is sent, which is 251-254, digital byte is 0 ~ 250. MCU can categorize the data storage, analysis, display and transmission to the PC in real time. 2.3 oxygen oxygen OEM OEM module module using Beijing multran Tong Yuan electronic instrument co., Ltd of DIGISAT g1b module. The module via the UART TTL port for communication with MCU. It can provide the following data: arterial oxygen saturation, pulse rate, volume scanning, bar graph, signal strength and status information. Its communication protocols and BCI communications protocol compatibility, data transfer, the transfer to the baud rate 4800bps format: 8-bit data + odd routing baud rate, transmission format for 4800bps: 8-bit data + parity bit + 1 stop bit. The MCU per second sent 60 packets and each packet is 5 bytes. 2.4 OEM OEM module blood blood pressure module using Beijing multran Tong Yuan electronic instrument co., Ltd of BTN602 noninvasive blood pressure measurement module. The module also TTL level of UART port to communicate with the UCM. To receive an external command, complete the appropriate operation, and returns the system status and corresponding data. Data format: start bit + 8 data bits + 1 stop bit, no parity, baud rate 4800bps. 3 software system design – central monitoring software the software using VC language design. In the past with the hospital management system, in accordance with the principle of unified standards, enabling a new combination of old system, fully guarantee the original system of independent reliability, modular software architecture and refactoring. The system administrator will first need to be patient information manual input to your computer system in which critical information saved to a central database server; then key in the database data, statistics and classification. According to the category of the data is replicated to all sectors of care center database, when you start monitoring needs, start-to-patient wards and records. Patient monitoring data and alarm level can be adjusted according to the care you need. Query, display key data and images, and the key to query data in a memo, image annotation, you can batch print output key data and image files. Its software system structure as shown in Figure 3. System security controls mainly from three aspects to guarantee the security of your database, image file security, user security permissions. Built on the NT Server on a database server SQL Server enables users and database operations staff login to authenticate. Only use a database user account and password for the login of the user to manage and maintain the database, users on different tables with different levels of permissions. File server uses port control access, guarantee the security of the file server. System software through wireless transceiver modules, using polling of data acquisition module, the low end if system in query timed patient information, skip this module queries, the query into other modules, the software records the query failures, when query failures exceeds a certain threshold, the system issues a warning signal.

Embedded WiFi technology in the medical monitoring of programmes

Currently, IEEE802.11 wireless local area network standard in voice communication, wireless, Office, etc are widely used, but mainly limited to PCs, laptops, and other common platform of wireless communication.

Wireless LAN in the electronics, industrial control, mobile handheld devices such as embedded application requirements in your environment. How do I in embedded system integration of WLAN broadband communication, become embedded system applications in a hotspot.

1 IEEE802.11 wireless LAN IEEE802.11b series including IEEE802.11, IEEE802.11a, IEEE802.1lb, IEEE802.1lg four standards.

This stage of the product more IEEE802.11b. This article is targeted at IEEE802.1lb standard, describes an implementation of embedded WiFi.

IEEE802.11b standard is in IEEE802.11 developed on the basis of the work in 2.4 GHz band, using CCK modulation technology, the highest transfer rates up to 11 Mbps, with deployment easy, reliable communication, strong anti-interference ability, low cost, flexibility, and portability, high throughput, and other characteristics.

It allows wireless users can get the Ethernet level of network performance, speed and availability, and can be seamlessly integrated in a variety of LAN technologies will produce a maximum meet user demand network. WiFi is the abbreviation of Wireless Fidelity, IEEE802.11b wireless standards exclusively. In introducing the work mode IEEE802.11b, first describes the basic concepts.

1.1 IEEE802.11b basic concepts

STA is the access portion of the wireless media, often called the network adapter or network interface card.

STA can be mobile or fixed. Each STA support authentication (authentication), authentication (deauthentication), encryption and data transfer, etc.

Basic service set BSS (Basic Service Set) is the basic form IEEES02.11b LAN, basic service set cell can contain multiple STA.

BSS basic service set has a coverage. In the coverage of basic service set STA can maintain mutual communication, each BSS has a basic service set identification number BSSID.

Independent basic service set IBSS (Independent BSS) is the most basic type of LAN IEEE802.11b, a minimum of IEEE802.11b LAN can only contain two STA.

In this mode, the STA to direct traffic. Because this type of IEEES02.11b LAN usually necessary arrangements so that the network mode is commonly referred to as ad hoc (Latin, translated as "ad hoc") mode. Site (STA) and basic service set (BSS) relate is dynamic, STA free to power on, power off, enter or leave the BSS coverage.

DSS (Distribution System Service) used to connect multiple BSS.

Due to the physical layer coverage limits determines can support of STA and direct communication between STA. To solve this problem, the introduction of DS (Distribution System), it can take multiple BSS constitute an extension of the network.

Access Point AP is short for General translation of "wireless access node" or "bridge".

Mainly in the media access control layer MAC play wireless workstation and wired local area network of bridges.

ESS (Extended Service Set), DS and multiple BSS allows IEEE802.11 constitute an arbitrary size and complexity of wireless network.

IEEE802.11b put such a network is called extended service set network. Similarly, the ESS also has an identifying name, i.e. the ESSID. 1.2 IEEE802.11b work patterns

IEEE 802.1lb has two working mode: Ad-hoe and Infra-structure model.

IEEE standard in stand-alone basic service set (IBSS) to define Ad-hoc mode of client-side collection, to basic service set (BSS) to Infrastructure mode defined by the client-side collection.

In Ad-hoc mode, the client cannot directly and the network of other client communications.

Ad-hoc mode is designed so that in the same spectrum coverage of customers can communicate with each other. If an Ad-hoc network mode customers want and the network of customer communications, the network must have a customer gateway, and performs routing functionality.

In Infrastructure mode, every customer will have their communication message to forward all communications AP.AP message.

These messages can be sent to Ethernet, can also be sent to the wireless network. This is an integrated Ethernet and wireless network infrastructure for application mode. Wireless access node is responsible for the management and roaming, and other bands command work. An AP connectsto 1024 site.

2 the design of embedded WiFi

Embedded WiFi structure and standard PC/OS platform.

To common microprocessor/microcontroller on WiFi communication, its hardware structure, software level must be reduced. The following spoke: Prism MAC instructions embedded WiFI design for software and hardware.

2.1 embedded WiFi hardware design

Embedded environment WiFi hardware interface as shown in Figure 1.

Compared with standard platforms, no PCMCIA Bridge. Figure 1 is an embedded environment PC2MCIA interface card and bus connections open MCU.

Since MAC including Memory space Prism and I/O memory two space, so you will need two films selected by or door control read and write space of choice.

PCMCIA package Prism MAC 26 root address line driver Prism MAC only needs to address lines A0 to A9, other address all grounding line. For bus not open processor, you can use the I/O port line simulation approach to reading and writing.

2.2 embedded WiFi software design

In Linux, WinCE, operating environments, you can use the manufacturers to provide the device driver to use the WiFi card.

This system is generally on hardware resources (such as CPU performance, storage capacity, etc) have higher requirements. For many embedded applications, due to a hardware resource limitations, many systems are simple OS (such as uC/0S etc) or no 0S environment running, then you need the entire software protocol for appropriate reductions.

TCP/IP protocol implementations in many articles have been more telling.

Here the main Prism MAC, for example, introduce infinite network drivers, namely embedded WiFi drivers.

Prism MAC provides consumers with a set of interface registers, registers, and through these Prism MAC for communication.

These registers is located on the Attribute Memory [2] space, you can use the direct access Memory address AttribLlte. Table 1 lists the commonly used registers PRISM MAC and its definition.

In order to read and write these registers, defines two functions: unsigned int getReg (unsigned int reg) and void selReg (unsigned int int val reg, usnigned).

Prism MAC drive is to command registers a command to manipulate MAC. Frequently used commands are allocated buffer, query the network card status, initialize the card, read data, write data, etc.

Prism MAC driver needs to provide for the upper MAC read and write functions, and some control function, the implementation of the function prototype is as follows:

void init_mac(void) void reset_mac(void) WORD wc_write(WORD*buff，WORD len) WORDwc_read(WORD*buff，WORDmaxlen) B00L get_wlan(void)

Reset_mac (void) is used to start the system or the system needs to be reset, reset Prism MAC while driving the use of a variable is initialized.

Inh_mac (void) function finishes initializing network controller and firmware to the NIC controller application for the use of the buffer required for the preservation of the RID. Wc_write (W0RD * burf, W0RD len) function in the buff len bytes written to the send buffer, MAC, and then write send command to send the command registers the network card, the function returns the actual length of data sent. Wc_read (WORD * buff, WoRD maxlen) function receives the input data. Returns the actual length of the data received, on the upper-layer protocols, call wc_read, can the data in the buff do protocol analysis. For TCP/IP, actually removed may be IP, ARP, and other types of messages. Get_wlan (void) by accessing EvStat register determine whether data is received, returns to judge the results. If so, you have the income to PrismMAC data frames share the data area. This function simply PrismMAC data frame first read out the fairly so Ethernet frame's header. Readout of data format for upper-layer protocols call get_wlan later, if the return value is TRUE, you can access the destination address, source address, the frame type and other variables to determine whether processing the data received. If you need to receive data, you can call the wc — read to read the data.

3 embedded WiFi in the application of medical care

Embedded WiFi in many areas have a wide range of applications.

Here is a concrete implementation of embedded WiFi — mobile monitoring systems. The monitoring system for hospital patient care, the use of embedded WiFi technology, available in a mobile environment, to be logging objects for digit grouping, real-time monitoring.

3.1 hardware structure

Mobile monitoring system consists of a server and multiple mobile intensive care unit.

Server-side include 1 PC or laptop, one wireless AP and 1 alarm, hardware structure and connections are relatively simple, in this no longer description.

Mobile monitors hardware structure including power supply module, pressure sensor, acceleration sensor module and a wireless network card modules.

Mobile monitors using Ti's ultra low-power microcontroller MSP430F148 as CPU.

Acceleration sensor module using the AD company's accelerometer ADXL202 for acceleration test, or gravity acceleration measurement, analysis, i.e. for patient tilt down test. Pressure sensor with MotorOla medical dedicated MPX2300DT, has good features and low voltage operation for linear output pulse measurement.

Power use 3.6 V battery-powered, after simple voltage transformation to satisfy the power requirements of mobile intensive care unit.

Wireless network cards using IntersilPrism2 PCMCIA network card chip set. It is a IEEE802.11b compliant network adapter. 3.2 software structure

Ad-hoc mode, move the monitors and the distance between servers is very short.

In order to increase the monitoring range, the mobile Telemonitoring system work in Infrastructure mode, the server-side AP and mobile monitors are equivalent to an STA, mobile monitors and servers can be in different BSS. Mobile monitors, AP's BSS together constitute an ESS, use DSS communication.

Server-side software module is used primarily to received from the network to the data in separating out the tilt, mobile monitors configuration information, pulse, and according to the information to the police, to move the monitors control.

Mobile monitors major complete Acceleration (tilt) data acquisition, pulse signal acquisition, data transceiver, sensor and stopping control.

The software can be divided into two levels: the application tier and the driver layer. Shadows for hardware drivers, driver layer above is the application layer.

Mobile monitoring systems with embedded WiFi technology, supports digital grouping, you can group objects to be logging detection, real-time data transmission at the same time; guarantee the reliability and accuracy of monitoring, in actual use has very good results.

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.