Using Radio-Frequency Identification (RFID) to Identify and Track Tags
RFID technology is being increasingly utilized for complex use cases, such as device provisioning to other radio networks, detecting the presence of required accessories or disposables, the usage count of accessories or disposables, sterilization status, manufacturing date codes etc. A typical RFID system consists of a reader or reader/writer and a ‘tag’ that holds data that can be read and written by the reader.
RFID reader/writers can be used as independent devices, much like a bar code scanner, or mounted inside of a device where they can sense the presence of a query or write information to the tag. The tag can either consist of a disposable card or can be a placed into the disposable accessory. Many mobile devices contain RFID reader/writer systems, allowing a mobile device to either check the status or query the disposable or device tag.
A primary advantage to RFID systems as they apply to medical devices is that RFID provides a far more efficient and effective system for identification of devices local to a specific area or patient. Due to the inherent localization capabilities of RFID, systems can be designed to track the location of tags in a facility. Localization systems typically deploy readers in specific areas, for instance an operating room or emergency room, that will report back the tags present in that reader’s field.
RFID tags that are paired to medical devices emit detailed data such as manufacturing date, lot number, shipping date, and more, all of which ensure proper identification and verification against potential logistical errors, or even counterfeit attempts. Furthermore, the information in the tag can be securely encrypted to greatly reduce the risk of counterfeiting or modifying the stored data.
RFID tags are available in many different standard as well as custom implementations and sizes. By balancing the performance tradeoffs of the RFID frequency band-- device size, antenna configuration and the storage technology used --the system can be optimized for differing use cases. One of the major considerations for use in device disposables is the ability to sterilize the disposable with the RFID tag embedded into the device. The sterilization method chosen will have a direct impact on the ability to support RFID in the device, or alternately the RFID device will drive the sterilization method. By designing a sterilization process that includes updating the tag information, the system can verify that the connected device is being used within its date code, usage count, is a valid device and has been through the sterilization process.
There are several standards for RFID, insuring interoperability of devices across use cases. The 2 main standards related to Medical uses are ISO/ IEC 14443 and ISO / IEC 15693. These standards are specifically written around HF (13.56 MHZ) operation, which has wide ranging product availability across different use cases. Adding a RFID reader to your product will require EMC testing and certification. The use of already approved modules can reduce the testing required in some instances.
Designing RFID into your system can greatly increase the ability and feature set of your device.