The emergence of portable medical devices has filled the shortcomings of difficult and annoying medical treatment in China. People can diagnose themselves at home, eliminating the necessity of going to the hospital and reducing hospitalization. At the same time, it can also reduce medical costs
At the same time, portable medical equipment can monitor vital signs before sending patients to the hospital, make the heart pacing again, and use ultrasound to check the internal situation of the body. Its goal is to contribute to the development of easy-to-use and interoperable home medical devices, and provide diagnostic data so that patients can obtain insurance compensation, etc
Let's analyze the mechanism and characteristics of portable medical devices, peel them layer by layer, and slowly "sting" our eyes
Block diagram of portable medical equipment:
Jn5148 - ultra low power consumption, high performance 32-bit MCU combined with IEEE802.15.4 compliant transceiver, supporting ZigBee & Jennet
For low-power wireless network applications, it has an enhanced 32-bit RISC processor to achieve high coding efficiency through variable width instructions; A multi-level instruction pipeline realizes low-power operation through programmable clock speed and various sleep modes. The device includes 128 KB ROM, 128 KB ram and various combinations of analog and digital peripherals. At the same time, the working current is less than 18 Ma, allowing it to work directly through the button battery... It is also extremely suitable for ZigBee Pro Network and intelligent metering
Advantages and features:
1. First class radio current consumption and a wide range of user peripherals
2. Adopt multi-functional 32-bit RISC CPU to realize high performance and low power consumption, and can run applications and ZigBee pro at the same time
3. The system BOM has few components, low cost and very low current, which can realize the solution of ultra long battery life
It can compensate for various changes, such as the change of humidity or pollution degree on the electrode. At the same time, it can detect the change of capacitance on the remote sensing board, so as to realize close operation without contact.
Pca8885ts - 8-channel capacitive touch and proximity sensor with automatic calibration and very low power consumption.
An 8-channel capacitive touch and proximity sensor detects capacitance changes on the remote sensing panel using the patented (edisen) method. The change of static capacitance is automatically compensated by continuous automatic calibration. The remote sensing panel can be connected to the IC through coaxial cable. 8 input channels work independently of each other. The sensors can also be arranged in a matrix through built-in options: interruption occurs only when two channels are activated at the same time, so as to prevent redundant channel output when both channels have been activated
Advantages and features:
1. Support matrix array sensor and remote connection of sensing plate
2. Adjustable response time and sensitivity (continuous automatic calibration, digital processing method, can be used with plexiglass with a maximum thickness of 6 mm)
3. Direct and latch switch mode, I C ultra fast mode (FM ) compatible interface
Pcf85063a - micro encapsulated real-time clock / calendar with alarm function and SPI bus
A CMOS real-time clock (RTC) and calendar, most suitable for low-power applications. The offset register allows fine adjustment of the clock. All addresses and data can be bi-directional I through two lines C bus serial transmission. The maximum data rate is 400 kbit / s. The register address will be automatically incremented after each write or read of data bytes... It is also suitable for various digital products and mobile devices
Advantages and features:
1. 400 kHz double line I Programmable clock output of C bus interface and peripheral devices
2. Alarm function, countdown timer, minute and half minute interrupt
3. Internal power on reset (POR), programmable offset register for frequency adjustment
Accurate and reliable, long-term stability, positive temperature coefficient and fault protection characteristics
PCT2075-I C bus FM , accuracy 1 , digital temperature sensor and temperature monitor
The accuracy is 1 C in the temperature range of 25 C to 100 C. Provide over temperature detection output and integrate a series of data registers: configuration register for memory device setting; A temperature register for storing digital temperature readings; Set point register for storing programmable over temperature shutdown and hysteresis limits and programmable temperature sensor sampling time tidle, which can be accessed through two-wire serial I The bus ultra fast mode (FM ) interface communicates with the controller
Advantages and features:
1. 1 MHz ultra fast mode (FM ) 30 Ma SDA driver can connect more devices on one bus, and is downward compatible with fast mode and standard mode
2. It has programmable temperature threshold and hysteresis set point during operation, and the power supply current is less than 1.0 in off mode A. It can save electric energy
3. When powered on, it can be used alone as a thermostat, an 11 bit ADC with a temperature resolution of 0.125 C
Pca6408a - low voltage, 8-bit I with interrupt output, reset and configuration registers C bus and SMBus I / O extender
Pass I C bus interface provides remote I / O expansion for most microcontroller series. When additional I / O is required while minimizing interconnection, NXP I / O expander provides a simple solution and has built-in level switching function, which makes these devices extremely flexible in a mixed signal environment where incompatible I / O voltages need to communicate
Advantages and features:
1. The latch output has a maximum driving capacity of 25 mA, which is used to directly drive the LED
2. Schmidt trigger operation allows slow input transition on SCL and SDA inputs and brings better switching noise immunity
3. When powered on, make all channels configured as input without pulse interference
Tfa9881uk - 3.4 w PDM input class D audio amplifier
Using 9 bumps WLCSP (wafer level chip package), with 400 M to receive audio and control settings through this interface. The dedicated silent mode is used to configure the control settings of the device, turn off the transition to the working mode, and trigger when the clock signal is detected... It is also extremely suitable for portable navigation devices, mobile phones and computers
Advantages and features:
1. The second-order closed-loop structure provides excellent audio performance and high supply voltage ripple suppression
2. It can completely prevent short circuit at both ends of the load and short circuit with the power line
3. Current limit that can avoid sound leakage, thermal protection function, undervoltage and overvoltage protection
2n7002bk - 60 V, 350 Ma n-channel trench MOSFET
N-channel enhanced field effect transistor (FET) is packaged with small SOT23 (to-236ab) surface mount device (SMD) with MOSFET technology. It has ESD protection up to 2 kV, compatible logic level and very fast switching. At the same time, it is especially suitable for: high-speed line driver and on-off circuit
Discrete semiconductor, DC / DC converter, LDOS
Ip3319cx6 - single channel common mode filter with integrated ESD protection network
Logic gate, data selector, GPIO, analog switch, LED controller, LCD driver, LED diode
Bza408b - Quadruple bidirectional ESD transient voltage suppressor
Today, many consumer medical devices simply display health monitoring results, leaving interpretation and recording to end users and their doctors. The new equipment can automatically record and transmit results through network connection.
At the same time, medical devices that help consumers have the following characteristics: simple and easy to use, highly reliable, safe, convenient connection, low power consumption (long battery life), support for a variety of voltages (especially low voltage), high measurement accuracy, small size, high cost performance
With so many advantages, so broad prospects and so practical performance, I believe no one can resist the naked Temptation
Do not forget the original heart, we can always... If you have thoughts, there will be repercussions

This series of articles introduces the application solutions of Hongke PCA in the medical equipment industry, including life science instruments, CT medical equipment, centralized control system and so on.
Application of PCAN interface card based on Hongke in hemodialysis machine
The number of patients with end-stage renal disease in China is huge and increasing year by year. Hemodialysis is a relatively mature alternative therapy, which can alleviate patients' symptoms and prolong patients' life. At present, China's hemodialysis machine market is mainly occupied by imported brands. The research and development of domestic hemodialysis machines with high quality and low price is not only the pursuit of China's medical enterprises, but also of great significance to the progress of science and technology and the development of medical undertakings.
Hemodialysis is to drain the blood in the body to the outside of the body through a dialyzer composed of countless hollow fibers. The blood and electrolyte solution (dialysate) with similar body concentration are inside and outside the hollow fibers, and exchange substances through dispersion / convection to remove metabolic waste in the body, maintain electrolyte and acid-base balance, and remove excessive water in the body.
Challenge
Shortcomings of traditional hemodialysis machine
In the actual treatment in the hospital, different modules need to be selected for treatment according to the situation of patients. After years of development, the function, safety performance and humanized design of domestic advanced models are comparable to those of foreign models, but domestic hemodialysis machines still have shortcomings. For example, most hemodialysis equipment does not have the functions of blood volume monitor, multiple sets of independent CPU systems and central networking. Although it has a variety of safety monitoring functions, the actual failure rate is high. Whether it is the appearance of the equipment, the principle of the hydraulic system of the machine, the design of parts, etc., there is a lack of innovation and lack of core competitiveness.
programme
Application and optimization of PCAN interface card based on Hongke in hemodialysis machine
In order to optimize the original prototype according to the new requirements and higher requirements, it is necessary to consider the system integrity, safety, accuracy and so on. Based on the above problems, Hongke PCA interface can be used to further R & D and optimization of hemodialysis machine.
Hemodialysis machine has many electronic control parts, which has high requirements for various indicators in the work of the machine. It needs an efficient and stable automatic control system to make dialysis run safely. Therefore, the control system of hemodialysis machine should meet the basic requirements of automatic control system, that is, stability, rapidity and accuracy.
For the control system of hemodialysis machine, its safety includes not only the control system itself, but also the executive parts controlled by the control system. When the control system has its own security, it should know the operation of the executive parts. When the actuator fails or does not work normally occasionally, the control system should be able to infer what parts have failed, what faults have occurred, what causes the faults and how to deal with them from the feedback of its components or according to the overall operation of the system.
Therefore, the functions of the control system structure of hemodialysis machine include: collecting the signals of various sensors to ensure the safety of dialysis; Control the movement of each pump to achieve accurate control of important parameters and meet the standard.
The control system of Hongke scheme can be divided into upper layer and lower layer. The upper layer is the main controller of upper computer and lower computer, and the lower layer is the motor and its driver, sensor module and three solenoid valve control boards. Its hardware structure is shown in the figure. The control system mainly includes the upper controller, the lower executive components and sensor modules. The upper computer is responsible for human-computer interaction function, obtaining medical staff instructions, displaying treatment parameters, etc. the main controller of the lower computer receives the instructions of the upper computer, completes the functions of the hemodialysis machine, and uploads the parameters to the upper computer. The motor, driver and solenoid valve are the executive components, The sensor acts as an information feedback component.
According to the requirements of the control system, the functions of each hardware module are divided as follows:
1) The host computer mainly realizes the human-computer interaction function, including guiding medical staff to carry out dialysis operation, displaying dialysis parameters in real time, providing maintenance personnel with maintenance platform, etc. The upper computer communicates with the main controller of the lower computer through CAN bus.
2) The main controller of the lower computer is used to realize the overall control of the hemodialysis machine, that is, collect sensor information such as temperature, conductivity and flow, control motors such as blood pump, degassing pump and flow pump, and control the drive of solenoid valve controller.
3) The motor and driver are the actuator of the control system, and the sensor module is the information acquisition device.
4) The solenoid valve controller is responsible for driving the solenoid valve and feeding back the status of the solenoid valve.
In this communication process, the can communication task is mainly responsible for the communication of devices on the CAN bus. We can give the highest priority to communication tasks to ensure that the control commands and parameters of the upper computer can be transmitted to the lower computer in time at any time. All communication between the upper computer and the lower computer is completed by this task, and other tasks can only contact the upper computer indirectly through this task. In the can receiving interrupt, it receives the data sent by the upper computer, caches the data, and triggers the can communication task by sending semaphore for analysis and execution.
HONGKE
Key characteristics of Hongke PCA interface card
high speed USB 2.0 adapter (compatible with USB 1.1 and USB 3.0)
two D-sub connectors are used to send and receive can FD and Lin messages (both are allocated by pins of can FD and LIN bus)
comply with can specification 2.0 A / B and FD
each can FD channel shall separate USB and Lin, with a maximum of 500V
can terminal can be excited by welding jumper
bus load measurement includes error frame and overload frame
induce error to generate can message for input and output
summary
The application and optimization of Hongke PCAN interface card in hemodialysis machine can meet the requirements of product stability, rapidity and accuracy. It can also be used with our handheld tester PCAN diag FD for various fault diagnosis, such as various fault diagnosis by processing CAN2.0 and can FD messages in the protocol layer, and oscilloscope function and voltage in the physical layer Resistance measurement function for fault diagnosis. At present, many manufacturers at home and abroad have used PCA interface card to upgrade their medical equipment. If you want to know more about PCA interface card, please contact Hongke for product information and trial opportunities.
Original title: [PCA medical application series] part6 application in hemodialysis machine based on Hongke PCA interface card
The source of the article: [WeChat official account: Guangzhou Rainbow Electronics Technology Co., Ltd.] welcome to add attention!

With the rapid development of hospitals, the demand for medical equipment in hospitals is increasing. Modern medical equipment has become a medical equipmentIt is an important symbol of hospital modernization and a powerful means for major hospitals to participate in market competition. In order to improve the medical level and market competitiveness, more and more high-quality, precision and advanced medical equipment have been put into use, which has continuously promoted the development of advanced medical technology.However, the use of high-end medical equipment also brings new challenges to doctors due to complex operation. In the use of equipment, doctors often need the technical personnel of the equipment manufacturer to give operation guidance. Moreover, the manufacturer may have to send technical personnel to the hospital site for equipment update and maintenance, which will not only consume a lot of time and labor cost, but also affect the normal use of the hospital and delay the timely treatment of patients.

Facing the needs of real-time operation guidance and efficient operation and maintenance of medical equipment, aiming at the hospital private network environment and domestic well-known remote control brand sunflower, a physical layer remote control solution - control A2 is given.The deployment of control A2 is simple and easy to use. Just connect the power supply to the control, connect one end of the USB data cable provided by the control to the control usb-b interface, and the other end to the medical equipment (virtual mouse and keyboard function), connect the HDMI adapter line to the control and medical equipment (output the master image of the controlled equipment), and then connect it to the control A2 through the hospital external network special line or 4G network card, After the medical equipment end is ready, the manufacturer's technicians only need to install the sunflower remote control software and remotely connect the control through the functions of [desktop control], [camera], [SSH] to realize the efficient remote operation and maintenance and operation guidance of the medical equipment.Flexible Internet access, not limited by the hospital's private networkSunflower control A2 supports three networking modes: wired, WiFi and 4G network card, which does not change the network environment of medical equipment. Whether it is connected to the network cable or connected to the Internet through WiFi or network card, it is control A2 that receives the network signal, which is independent of the medical equipment network and gets rid of the problem of limited hospital network.Plug and play, the hospital controls the use rightAs a pure hardware external remote control tool, control A2 is small and exquisite, plug and play. If doctors need operation and maintenance troubleshooting in case of operation problems or equipment faults, they only need to connect control A2 to the medical equipment and notify the manufacturer's technicians for remote connection. After use, the hospital can unplug the control in time. The whole process is led by the hospital to ensure the safety of medical information.High compatibility, not limited by equipment systemControl A2 is the physical layer link of intelligent hardware. It does not need to install any software and is compatible with a variety of operating systems. No matter what operating system is used for medical equipment, it is not limited by the system and can quickly realize intelligent remote control.

With camera and whiteboard, remote guidance is more convenientThe USB interface of control A2 supports an external camera. In the remote operation guidance, the camera can help the technicians of the equipment manufacturer understand the operation details of the doctor in real time and help the technicians better carry out remote guidance; In particular, with the sunflower remote control software, the "whiteboard" function can be opened in the remote control, and the operation demonstration can be carried out through the whiteboard, so that technicians can solve the operation problems more conveniently and intuitively when guiding doctors to operate the equipment remotely.Cross platform use, mobile phone / tablet / PC remote operation anytime, anywhereSunflower supports flexible login on mobile phones, iPads, PCs and other platforms. No matter where the technicians are, they can quickly log in to the sunflower control terminal through their portable devices as long as they have a network, so as to provide doctors with remote operation guidance and equipment operation and maintenance in real time.It is worth mentioning that the sunflower data transmission adopts AES / RSA 256 bit asymmetric algorithm encryption and double authentication of user information, which realizes the encryption protection of user information and session, and comprehensively ensures the information security of the hospital.Through the sunflower control A2 solution, medical equipment manufacturers have perfectly solved the problems of remote operation and maintenance and operation guidance of medical equipment. Control A2 is simple and easy to use, with low cost, greatly saving operation and maintenance cost, and the deployment is flexible and highly controllable, meeting the strict requirements of the hospital for safety problems and realizing mutual benefit and win-win.Moreover, as a powerful physical layer remote control hardware, sunflower control A2 has been successfully practiced in the fields of remote consultation, remote operation live broadcast, remote operation and maintenance of medical information management system, and provides a simple, easy-to-use, safe and reliable low-cost solution for telemedicine.About sunflower remote controlSunflower is the only remote control service provider with integrated software and hardware in China. It has been deeply engaged in the remote industry for more than 10 years. It has independently developed sunflower remote control software and a variety of intelligent hardware such as start-up stick, start-up socket and control. It crosses the mainstream operating system and penetrates all kinds of complex network environment to provide safe, efficient and Stable customized full surround remote control solution; With a high degree of technological innovation ability, it has pressed similar products at home and abroad, provided high-quality remote control services for 120 million hosts, 30 million users and 50000 enterprises, and reached cooperation with well-known government and enterprise institutions such as Changhong, Huawei, Midea, China Communications, Chinese Academy of Sciences, Peking University and Shanghai Jiaotong University, which has been highly recognized by the majority of users.

Power supply standardIEC 60601-1:2005 and accompanying documents specify the safety and basic functional requirements of the power supply. The standard appears in the form of ANSI / AAMI document in the United States and in the form of "euronorm" in Europe and around the world, with some local differences. Since January 2021, the latest revision (a1:2012, a2:2020) has updated the standard, deleted outdated references, corrected errors and made it better consistent with IEC 62368-1. The current medical EMC standard IEC 60601-2 is the 4th Edition.Built in medical power standard

AC powered medical devices can have "built-in" power supplies or lower power external adapters. If it is an internal product, the product designer should consider high voltage and high energy, and usually choose to buy a "medically certified" power supply. However, the final product is the product certified for this application, so there are other considerations, such as labels, connectors, internal wiring of power supply and fuses.Due to grounding, external wiring and interference from other noise sources, the built-in power supply conforming to EMC standards cannot be guaranteed to pass the test. A common practice is to add another EMI filter at the AC inlet, which may be included in the connector. However, it should be noted that the leakage current limit should not be exceeded. For the most stringent CF product rating, the leakage current limit can be as low as 10 a. The leakage of external filter may directly lead to the internal leakage of AC power supply, there is a risk of interaction between external filter and internal filter, and may even worsen EMI.Secure power solutionsThe safe solution should select the target application and specify a power supply with 2 x MOPP certification and EMC compatible performance. For example, power supplies from recom racm230-g, racm550-g and the recently released racm-1200v series.Their peak or rated power is 230W, 550W and 1200W respectively. When fans are not allowed (usually in medical environments), these products can be floor cooled. All products have 2x MOPP / 250V AC rating to prevent leakage to ground (racm550 / 1200). The safety barrier in each recom power supply is shown in Figure 2.Figure 2: safety fence racm230 / 550 / 1200 seriesFigure 3: a 2x MOPP DC / DC converter provides SIP / SOP isolationUsing a medically certified power supply (such as the power supply of recom) is a reliable way to ensure that the safety and EMC standards required by various medical application environments are met. It would be a lower overall cost approach if development, certification costs and time to market were taken into account.

Recom is a good choice when selecting AC / DC power supply for medical equipment. Eurotime electronics, as a distribution partner of recom, provides local inventory and technical support.Original title: eurotime classroom | AC / DC power supply in medical applicationsThe source of the article: WeChat official account: Euro time electronic RS] welcome to add attention! Please indicate the source of the article.

Power supply standardIEC 60601-1:2005 and accompanying documents specify the safety and basic functional requirements of the power supply. The standard appears in the form of ANSI / AAMI document in the United States and in the form of "euronorm" in Europe and around the world, with some local differences. Since January 2021, the latest revision (a1:2012, a2:2020) has updated the standard, deleted outdated references, corrected errors and made it better consistent with IEC 62368-1. The current medical EMC standard IEC 60601-2 is the 4th Edition.Built in medical power standard

AC powered medical devices can have "built-in" power supplies or lower power external adapters. If it is an internal product, the product designer should consider high voltage and high energy, and usually choose to buy a "medically certified" power supply. However, the final product is the product certified for this application, so there are other considerations, such as labels, connectors, internal wiring of power supply and fuses.Due to grounding, external wiring and interference from other noise sources, the built-in power supply conforming to EMC standards cannot be guaranteed to pass the test. A common practice is to add another EMI filter at the AC inlet, which may be included in the connector. However, it should be noted that the leakage current limit should not be exceeded. For the most stringent CF product rating, the leakage current limit can be as low as 10 a. The leakage of external filter may directly lead to the internal leakage of AC power supply, there is a risk of interaction between external filter and internal filter, and may even worsen EMI.Secure power solutionsThe safe solution should select the target application and specify a power supply with 2 x MOPP certification and EMC compatible performance. For example, power supplies from recom racm230-g, racm550-g and the recently released racm-1200v series.Their peak or rated power is 230W, 550W and 1200W respectively. When fans are not allowed (usually in medical environments), these products can be floor cooled. All products have 2x MOPP / 250V AC rating to prevent leakage to ground (racm550 / 1200). The safety barrier in each recom power supply is shown in Figure 2.Figure 2: safety fence racm230 / 550 / 1200 seriesFigure 3: a 2x MOPP DC / DC converter provides SIP / SOP isolationUsing a medically certified power supply (such as the power supply of recom) is a reliable way to ensure that the safety and EMC standards required by various medical application environments are met. It would be a lower overall cost approach if development, certification costs and time to market were taken into account.

Recom is a good choice when selecting AC / DC power supply for medical equipment. Eurotime electronics, as a distribution partner of recom, provides local inventory and technical support.Original title: eurotime classroom | AC / DC power supply in medical applicationsThe source of the article: WeChat official account: Euro time electronic RS] welcome to add attention! Please indicate the source of the article.