Characterizing the 2.4 GHz Spectrum in a Hospital Environment: Modeling and Applicability to Coexistence Testing of...

Area of Science:

• Electromagnetics and Signal Processing
• Biomedical Engineering
• Wireless Communication Systems

Background:

• Increasing use of unlicensed spectrum by medical and nonmedical devices necessitates wireless coexistence assessment.
• Ensuring medical device safety and effectiveness requires understanding device interactions in shared radio frequency environments.

Purpose of the Study:

• To establish a generalized framework for modeling the wireless environment to approximate device coexistence probability.
• To apply this framework through a spectrum survey in a hospital setting.

Main Methods:

• Conducted an 84-day spectrum survey in the 2.4-2.48 GHz Industrial, Scientific, and Medical (ISM) band within a US hospital.
• Utilized a custom platform to monitor power flux spectral density and received power.
• Calculated channel utilization for three 20 MHz bandwidth channels (relative to IEEE 802.11 channels 1, 6, and 11) and fitted data to a generalized extreme value distribution.

Main Results:

• Observed low channel utilization (<10%) in the surveyed hospital environment.
• Documented sporadic occurrences of higher channel utilization (>50%).
• Demonstrated the applicability of the generalized framework for environmental modeling.

Conclusions:

• The findings complement existing wireless coexistence testing methodologies.
• This research can inform the development of consensus standards for wireless device coexistence testing and risk management.
• The framework provides a foundation for evaluating the probability of medical devices coexisting in their operational environments.