Improve data access and software upgrade capabilities for healthcare and disease monitoring equipment

Disease monitoring equipment is often used to measure patients' vital signs, such as blood pressure, heart rate and other parameters. The requirements for managing these important data go far beyond simple inventory control. The equipment needs to be able to provide equipment inspection, calibration and self-test results, and have security upgrade functions, while minimizing equipment downtime. Maintenance personnel often stick labels that record maintenance information on equipment. Due to the need to record a large amount of information, labels are gradually damaged after a period of time, and label stickers are no longer a reasonable choice. With the rapid development of technology, disease monitoring equipment often requires software upgrades.

　　Unlike static label stickers, dynamic dual-interface RFID EEPROM electronic tag solutions can record measurement parameters for future reading, and can also log new data into the system, such as calibration constants and inspection information, without any external connectors. Dual-interface electronic tags can be connected to disease monitoring equipment through the I2C interface. When the device is running, the device can read and write electronic tags through the I2C interface. Even if the disease monitoring equipment is not working, medical staff can read and write electronic tag data through an ordinary electronic tag reader that complies with the ISO 15693 13.56 MHz RFID standard. Because it can ensure that the data is up-to-date, secure and readable and writable at any time, dual-interface storage makes the radio frequency identification technology chain more perfect.

　　The target applications of the dual-interface passive RFID system include equipment maintenance conditions and records, authorized accessory verification, sensors, counterfeit product identification, disposable reuse control, and adding new authorized products. When the monitoring equipment is working or on standby, the operator can read and write the data in the dual-interface RFID through the monitoring equipment. When the equipment is turned off, the operator can use the electronic tag reader to manage the data in the dual-interface RFID. This great advantage creates more opportunities for designers.

　　Disease surveillance system classification

　　Disease monitoring systems are generally divided into three categories: bedside monitors, portable handheld monitors, and body-worn monitors.

　　Bedside monitors play an important role in providing medical monitoring and diagnostic information. The information provided by bedside monitors accounts for an increasing proportion of the monitoring information required by healthcare professionals. Bedside monitoring equipment is usually installed in important intensive care monitoring areas, such as intensive care units. Currently, most bedside monitoring equipment can be connected to the central monitoring system through the hospital network and exchange data through the facility network.

　　Management of portable monitoring devices is challenging because these devices seem to be able to “leave the group or even get lost.” While checking the location of a device is beyond the scope of this article, understanding what is happening with the device can be very helpful in ensuring continued compliance and verifying the identity of the device owner.

　　Although wearable monitors are not a new invention, the number of measurement methods and data volumes are increasing rapidly as products are upgraded, which is where a dual-interface RFID solution comes in. As a gateway to the inner workings of the system, the dual-interface RFID solution connects to the monitoring device without tangled cables, thus improving the practicality and service life of the monitor.

　　Body-worn monitors can be further divided into the following categories :

　　• Mobile/wearable personal monitors (MPM): Wearable personal monitoring devices monitor the vital signs and activities of patients with chronic diseases in real time and store and forward measurement data or alarms.

　　• Mobile Aggregators: Smartphone-like devices with or without external sensors that can report patient status via mobile wireless technology.

　　• Wearable healthcare devices: Healthcare devices worn on the wrist/arm/chest or sensors embedded in the fabric of shoes and shirts to detect vital activity characteristics such as heart rate, breathing, and pace.

　　• Remote Patient Management (RPM) devices: Special monitoring devices with patient-specific sensors built in. These systems are equipped with sensors that are customized by the hospital specifically for the patient and report all vital sign parameters, such as heart rate and the patient's position (standing or lying down).

　　Whether it is a bedside monitor, a portable or wearable monitor, all disease monitoring devices face common challenges: how to keep the device up to date with the latest software, calibration data or maintenance records? How to detect a faulty device?

　　Benefits of managing system data

　　A simple equipment failure can have a big impact on disease detection report results. Of all the problems that have plagued the industry for years, monitoring equipment backup battery failure is undoubtedly at the top of the list. System self-tests fail when they should, and alarm when they shouldn't. For bedside monitoring equipment, central monitoring can report the failure and send maintenance personnel to troubleshoot, thus avoiding serious problems.

　　Portable and body-worn monitoring devices present designers with a more challenging set of problems. One problem is that these two devices are the fastest growing markets, and interoperability standards have only recently become a real focus. For example, the Continua Health Alliance recently specified four major interoperability interfaces: USB, Bluetooth, Bluetooth Low Energy (BTLE), and ZigBee. What all four interface technologies have in common is that the monitoring device must be powered and active (i.e., performing monitoring functions) in order to report faults through these interfaces, indicating that the device is functioning properly. When these devices are turned off, the monitor is often disconnected from the error information, making it more difficult to mitigate or even detect any problems.

　　Portable and body-worn monitoring devices have another emerging challenge. In order to be waterproof and dustproof, easy to clean, and not damage electronic components, today's portable and body-worn monitoring devices adopt an overall sealed design. In this case, adding connectors or adding functions to the connectors will inevitably increase the size, cost or system complexity of the sensor end.

　　Reading and writing related materials

　　Mastering readable and reliable traceability product information and understanding all product information from production line to working status is very useful for managing and executing these assets (monitoring equipment). For a long time, equipment manufacturers have used codes on label stickers to concisely describe product information such as manufacturing date, revision, production line/factory, serial number, etc., and then affixed these labels to related products. This type of information is the basic information required for quality control and equipment information traceability.

　　Today's systems require information such as option configurations, multiple sensor calibration constants, maintenance intervals, etc. Some systems also provide user-programmable "hot keys" that allow users to set and lock these functions. Equipment maintenance management alone requires so much information, not to mention the real-time information of the "Check Engine Status Light". The ability to record and read error events in real time can greatly reduce equipment maintenance costs and reduce maintenance time.

　　By connecting an electronic tag to each device via the I2C interface, medical staff can record and instantly read error events.

Dual-interface storage for flexible use

　　According to storage requirements, these dual-interface memory chips can be divided into multiple logical storage areas, sharing the same I2C compatible bus and antenna. This solution not only expands the application range of storage, but also allows designers to set a 32-bit security password in the storage or any logical area to establish a storage access permission mechanism.

　　
Figure M24LR64 Dual Interface RFID EEPROM

　　The simplicity of the design gives designers flexibility in how they apply this dual-interface electronic tag. Now you might be wondering, what happens if the device is receiving system commands while reading and writing the electronic tag? Most engineers know that designing a simple system usually involves moving complexity into the chip. For example, there is such a circuit in STMicroelectronics' M24LR64 dual-interface RFID EEPROM chip, which can handle the parallel communications that may occur and drive system activities from the RF and I²C sides.

　　Design standards for monitoring equipment

　　The design criteria for disease monitoring equipment is a complex array of factors related to where and what patients are monitored. The evolving technology and standards require close tracking of the equipment manufacturing and maintenance data mentioned above. Another difficult issue to deal with is counterfeit and fake accessories, sensors, and other measuring devices worn by patients. For directly inserted accessories, designers can introduce a data encryption method into the system that can be read by the main processor. Of course, this solution only applies to products such as smart sensors. For disposable accessories, designers may want to introduce a low-cost reader/writer that can read and write the electronic tag in the accessory, and then write a secure device code (Challenge Code) into the dual-interface RFID chip.

　　
Figure example: Adding a reader to verify the identity of a one-time attachment

　　When new or authenticated devices are introduced to the market, it is not difficult to add a device code to the monitoring device. As the problem of counterfeit products becomes more and more serious, the market needs a reliable and low-cost solution like the M24LR64 dual-interface RFID EEPROM chip.

　　ISO standards, interoperability, security

　　The current RFID technology uses the 13.56 MHz ISO/IEC 18000-3 Mode 1 air interface protocol (based on ISO 15693). The maximum read/write distance of this standard is 1 meter, and the specific distance depends on factors such as the size of the antenna. Due to its extremely low operating power and high security, this RFID standard has been widely used in various devices around the world. Recently, we have also seen some newly launched Android phones equipped with readers and writers compatible with this standard.

　　in conclusion

　　Designers' challenges have not become easier than before, but fortunately, there are many solutions available on the market today, some of which can be used in unrelated industries. When designers realize that a series of difficult problems can be easily solved with a low-cost, low-power and easy-to-implement chip, such systems seem to have a wider application prospect in the medical market.