By Thomas Lavallee
June 6, 2011—Managing patient-monitoring equipment typically used for measuring patients' heart rate, blood pressure and other vital signs goes far beyond simple inventory control, to include the need to ensure inspection, calibration, self-test results and safety upgrades, while minimizing down time. Adhesive paper labels applied to equipment and used to record service data are no longer a reasonable option, due to the large amount of information required, as well as the tendency for such labels to become damaged over time. With the technology advancing quickly, patient-monitoring equipment is often capable of being upgraded via software.
A dual-interface,
RFID-based
EEPROM (
electrically erasable programmable read-only memory) solution is dynamic, and can record internal parameters for later readout, as well as write new data into the system, such as calibration constants and inspection information, without the need for additional connectors. A dual-interface
RFID tag can be connected to electronic patient-monitoring equipment via an I²C port, and the tag's memory can be read and written to using that port while the equipment is in operation. Reading can also be accomplished regardless of power to the equipment, via a conventional RFID
reader compliant with the
ISO 15693 standard for 13.56 MHz RFID tags. The ability to have this data current, secured yet readily accessible when needed completes the technology chain.
Applications for a dual-interface passive RFID system include access to maintenance requirements and records, verification of approved accessories, sensors and related components, and counterfeit goods rejection, as well as ensuring that one-time use items are discarded and not reused, and the addition of new approved devices as available. The advantage of a dual-interface RFID solution opens a designer's options by allowing data to be managed from the monitoring equipment during operation or standby, while enabling the reading and writing of data via RFID readers, even if the equipment is powered down.
Monitoring System Categories
Patient-monitoring systems typically fall into three broad categories: bedside, portable and body-worn.
Bedside monitors play a significant role in providing ever-increasing portions of the information required by health-care professionals. These devices are often assigned to specific areas within a medical facility, such as critical and intensive-care units, and most are now capable of connecting with a central monitoring system on a hospital network, on which data can be exchanged through a facilities network.
Portable monitors are a bit more challenging, as they seem to have the ability to walk off and become lost. Although detecting location is not part of this discussion, knowing what happened to equipment can be a big help in addressing compliance issues and validating ownership.