Cold-Chain Logistics in Healthcare: A Modern Alternative



Pat Furlan
07/13/2011

Environment and application problem:

The enemies of various drugs and reagents sound simple: time and temperature. But their effects can be devastating in terms of cost and efficacy, not to mention a supplier’s reputation. An accurate, cost effective, and seamless operation to monitor shelf life and temperature during shipment and before actual use could save money, time, and perhaps even lives.

Drug and reagent manufacturers and their customers, logistics ompanies and their shipping employees, as well as other necessary parties could access their data via secure internet sites in an easy to use format, using standard industry terminology and methodologies.

Ideal solution:

The idea would be to have the devices at the box level attached with a tag or similar shipping label with a small adhesive patch. This label or patch would include, in a very small size, a Real Time Clock (RTC), an RFID (ISO15693), and a temperature sensor. When a RFID (or any ISO-15693 read/writer like NFC) communicates with a device or scans with the appropriate security exchange, the reader could download the time/date/temp information. The smart shipping label’s data is downloaded and would contain periodic "captured temperature correlated to indicated time." The data can be presented in raw terms, for instance every 5 or 10 minutes the temperature can be measured and stamped with the time and date when it was actually measured.

This raw data could be analysed to determine if any violations in temp were experienced and for how long. Since temperature does not change very rapidly, the temperature does not need to be measured in seconds but in minutes. The data could be presented or captured when the actual temperature changed. For instance, if it did not change more than 1 degree C then there would be no new log. If the temperature exceeded this previously determined 1 degree mark, it would time stamp this event and time stamp again if the 1 degree mark was again exceeded. In this way, the data could be easier to analyse for longer periods on time (months vs. weeks).

The implementation is fairly straight forward. The sensor device would need to be initialised or configured prior to shipping when its label or patch is attached.

The initialisation would consist of starting the low power circuitry (uC) and loading the RTC registers with the current time and information through the RFID device.

At the destination or receiving location, the data can be loaded into a company’s computer system or onto a web server, for example, to be monitored as necessary. Then both sides can know if there where any issues or violations in temperature that would affect or destroy the efficacy of the drug, reagent, blood, or other medical or pharmaceutical product.

The prevention of medical emergencies is another relevant function of time and temperature control. Food poisoning can be avoided when chilled foods are stored at 40°F (4.4°C) or lower to inhibit microorganism growth. Such sensors would make it easier for food service professionals to monitor this critical temperature as required by the Food and Drug Administration HACCP (Hazard Analysis Critical Control Points) guidelines.

Shipping companies in the supply chain could benefit by being able to prove their effectiveness through time and temperature stamps, which could thereby affect the way insurance is determined. The advantage to the patient would be having access to the right treatment and all parties in the healthcare chain, from pharmaceutical company through shipping provider to medical professional, having confidence in the drugs’ or reagents’ performance.

Architecture and Implementation:

The basic elements needed for such a system consist of an antenna tuned to 13.56 Mhz, a battery, a simple 8-bit microcontroller, and an RFID dual interface. Furthermore, the solution needs to use very little power and should be able to run in the shipping and holding environment for the longest possible time, which would need to be longer than the longest shipping time to cross the globe.

The microcontroller in our example is one that would run as low as 1.8V, with the RTC running continuously, in the order of a few hundred nano-amps. The dual interface device would need an I2C interface on one side, which could communicates to the microcontroller, and on the other side would communicate via a standard ISO-15693 protocol. This solution would need to be able to operate off a variety of battery technologies, but when using the pervasive 2032 lithium primary cell, would be able operate as long as a year.

Looking forward

Another key enabler taking place today is the ‘smart phone’ with applications that can be written or are available today; examples are iPhone™, Android™, etc… With these new generations of smart connectivity devices, applications can be quickly ported and data can be read from a node with mobile device and sent to the cloud for supply chain management. Many upcoming smart phones will be capable of NFC/RFID utilising ISO-15693 and IS0-14443 readers, which use the same frequency.

Such products and solutions are a great example of using a industry standard protocol, like RFID-ISO 15693, for unique application solutions through innovative silicon IC design.

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