Wisconsin Blood-Tracking Study Moves to Phase 2

When the project first began two years ago, Briggs says, there were few tags available offering the memory capacity necessary to store the amount of data the tags would be expected to hold. Since then, the group has discussed with vendors about creating a passive HF tag for its prototype system, with the additional memory (researchers expect to require 3 kilobits) divided into several sections (that is, separate blocks of data regarding the donor and the blood recipient), some of which would be locked on the tag. Such tags would be based on the ISO 15693 standard, but would have extra memory partitioned into blocks, as specified by the BloodCenter group. According to Briggs, off-the-shelf RFID interrogators compliant with the ISO 15693 standard would be able to encode, lock and read these tags.

When a blood center draws blood, its staff will use a blood bag with an RFID tag attached with adhesive, then write the date and time onto the tag, along with the blood's type, donation identification number, and expiration date and time. The center will then process the blood, typically breaking it down to several containers of products, each with its own RFID tag, with data written to it detailing the product's origins. When a bag of processed blood leaves a blood center en route to a hospital, its tag will be read once more, in order to register that bag's departure, and the time and date of that activity will also be written to the tag. When the hospital receives the blood bag, it will utilize a separate section of the chip's memory to write such data as the receiving patient's medical record and date of birth, as well as the time and date. When the blood product is administered to the patient, the bag tag will be read again, thus confirming the patient is receiving the proper blood products. In some cases, if a transfusion is delayed, data indicating such a delay can be written to the tag, and the unused product bag can then be returned to the blood bank.

With the system's design already determined, Briggs says, the team needs only to select vendors for the hardware, and to create software to store data, which could then be shared by hospitals and blood banks. The technology will need to be generic, she says, meaning it must be able to integrate with any blood bank's existing blood establishment computer system (BECS). "The RFID software itself will not be that complicated," she indicates, "but it needs to be able to integrate with the BECS." The system is expected to be made available to blood centers and hospitals following the two-year research process, which includes piloting the technology.

Plasma is one of the more difficult products to work with, in terms of the tags themselves, because of the extreme cold at which plasma is stored: -18 degrees Celsius (-0.4 degrees Fahrenheit). As such, the researchers chose to begin with red blood cells and platelets, which are stored at refrigeration or room temperature. If the RF transmission affected the temperature in either red blood cells or platelets, Briggs notes, there would be no need to study plasma. "With additional funding," she says, "we can now also take a look at the tags in a more difficult environment. This will include the durability of the tags under extreme cold, as well as additional clinical limit testing of plasma exposed to HF."

Due to the large volume of blood transfusions typically administered, hospitals could expect a shorter ROI, Briggs says, estimated at between two and three years after the technology is acquired.