06 Nov Using NFC to Automate and Secure Cartridge Interfaces in Life Science Instruments
Across life science and medical industries, it’s extremely common to see products with a durable instrument interfacing with one or more cartridges. Modern diagnostic devices regularly support unique assays that must be identified correctly per test. Similarly, pharma and drug delivery consumables look to track usage and expiration of consumables for patient safety. These products find themselves in need of a reliable, inexpensive, and secure interface to facilitate communication between the instrument and cartridge.
Near field communication, or NFC, is a scalable, elegant, wireless solution for a cartridge to instrument interface. NFC provides wireless communication over short distances, typically less than 2-3cm. In its most common form, an NFC solution uses an active reader/writer in the instrument that wirelessly interrogates a passive tag on the cartridge. This scheme is superior to traditional barcode scanning because NFC does not require a clear line of sight and can both read and write information to the cartridge. Passive tags are commonly designed in a sticker label form factor that’s easy to apply and low-cost.
Applications
Automating Cartridge Identification
Instruments need to identify cartridges’ serial numbers, expiration dates, lot numbers, and assay specific inputs, ideally without additional error-prone user steps. NFC excels at this by allowing the system to load the right settings by reading pertinent cartridge information automatically upon loading the cartridge.
Example: In a recent drug delivery application, Key Tech implemented NFC to store and send crucial information about each cartridge’s drug contents and delivery protocol. A passive cartridge tag is programmed during manufacturing, then when a patient begins treatment, the device reads the tag and adjusts settings accordingly. To refine and develop this architecture, Key Tech built prototypes to evaluate NFC performance in a representative environment. We investigated the sensitivity of a reader to factors such as tag positioning, multiple tags, and metal instrument framing. The outputs from these tests informed the design of the antenna, enclosure and framing, and instrument workflow.
Enforcing Cartridge Use Limits
An NFC system can also write information to a passive label, unlike other labeling methods such as barcodes. This is critical functionality for tracking changing cartridge metadata, making NFC ideal for cost-sensitive applications where cartridge overuse must be prevented.
Example: Key Tech integrated an NFC solution to track cartridges with a finite number of runs. The system was able to enforce the use-limit by updating a field in the tag’s memory after each test. The instrument would reject a cartridge if the cartridge tag indicated it had completed the maximum number of runs.
Securing Data
Data security is crucial in clinical applications and NFC protocols are designed to meet these robust security requirements. Features include:
- Data-write lockouts can prevent users from modifying cartridge information once it’s left the manufacturing facility. Some NFC tags support commands to lock single blocks or the tags entire memory.
- Tamper-proof tags feature an extra loop of wire that can be broken by tearing the tag. The tag IC recognizes whether the wire is open or closed. By placing the tag across a breakable seal and simply reading the tag to check the state of the tamper loop, the instrument can identify when a cartridge has been tampered with or illegitimately refilled.
- Encryption of NFC readers and tags allows each party to verify the identity of the other prior to sending any information, ensuring that only authentic instrument readers and cartridge tags may send information to each other.
Key Tech’s Approach to NFC Integration
Off the shelf readers and tags are a good starting point for evaluating use environments and system constraints in early product development phases. Key factors such as tag size, placement, distance from the reader, and nearby sources of interference impact reliability. Once the instrument and cartridge form factors are determined, the NFC reader should be customized to optimize performance. That said, NFC may be a straightforward addition to the product electronics architecture, providing a low-cost and scalable solution for products requiring connectivity. Key Tech has designed and tested custom NFC solutions for both medical and commercial devices. Reach out to us at TalkToUs@keytechinc.com to find out more about adding NFC to your next project.
In her free time, Caitlin plays many hours of tennis. On rare occasions, she likes taking a break from tennis to play video games, go whitewater rafting, or go on a hike (especially if dogs are involved).