Assuring the integrity of data communications
and wireless coexistence
Several licensed spectrum bands have been allocated by the US Federal Communications Commission (FCC) for sole use by medical devices. However, many medical device manufactures have been enticed by inexpensive and abundant technology designed to operate in the unlicensed Industrial, Scientific, and Medical (ISM) bands. IEEE 802.11b/g/n (or WiFi) and the new 802.11ac (or Bluetooth and low power Bluetooth, Zigbee, and RF ID’s) are examples of such technologies. The result of increased use is an overcrowded ISM band. Careful assessment of medical device operability and interoperability in the ISM band is critical for validating medical device coexistence with other devices sharing the band. Assuring the integrity of data communication is imperative for patient safety.
Dr. Refai and his research team have recently collaborated with scientists at the US Food and Drug Administration Center for Devices and Radiological Health (FDA CDRH) to conduct thousands of experiments evaluating the temporal and spatial characteristics of the radio frequency (RF) channel under various testing conditions and setups (e.g., homogenous vs. heterogeneous wireless networks; single communicating pair vs. multiple pairs). Since then, the research team has collected ISM channel utilization data from hospitals, sporting event stadiums, and university student dorms. Our researchers' work includes:
- Detailing various ISM wireless technologies and highlight design factors for improving coexistence,
- Introducing a newly developed coexistence testing protocol for WiFi, Bluetooth, and Zigbee,
- Describing temporal characteristics of an RF channel under various node density and networking conditions,
- Presenting channel utilization data collection,
- Performing long-term spectrum surveys of various hospital facilities, and
- Investigating wireless behavior of medical devices operating in the MICS band in actual hospitals and clinics.
