By now the conference was losing a bit of momentum. I slept in rather than attending the last keynote and scoring a free breakfast. I started the day with "Mobility Architecture: Designing a Mobility Infrastructure" presented by connectologist Dave Hoglund (Johnson Controls) and Milind Parandare (Patni Computer Systems). Their story was, "Guess what? Everything's going wireless, and it's okay." Dave presented a comprehensive (if scary) overview of wireless technologies that are either coming to hospitals, or already in them. The key to survival will be proper needs assessment, planning, system design, and management - and will have a huge impact on both biomeds and especially IT.

The proliferation of both wireless systems and sources of RF interference require that any wireless system be properly designed, installed, and validated to ensure proper operation. This is regardless of whether the frequency used is "protected" (from intentional sources of interference) or uses an unlicensed band like ISM. Wireless medical devices have been deployed for years on unlicensed bands and proven to be as safe and drop-out free as systems using licensed bands. One of the first vendors to deploy on unlicensed bands was Welch Allyn; GE, Philips and most of the rest of the rest of the industry followed suit. The latest example is Draeger's OneNet, where real time monitoring data and alarms runs on wireless and wired networks with other hospital data (i.e., no "private" network).

Next up was "An Effective Decision Making Process for Selecting and Installing Wireless Technology," presented by Mark Kotfila and Paul Coss of Philips, and the ubiquitous Rick Hampton of Partners. As a vendor selling proprietary radio technology for their patient monitors and telemetry, I thought Philips did an admirable job of presenting a pretty unbiased view of the problem. They were also up front about Philip's position that medical devices and IT should be on "separate networks." Given that there are so many considerations in purchasing wireless medical devices beyond the wireless technology, and that all the technologies considered work, I'm not sure that the considered analysis that was presented will be a big factor in purchase decisions. Some interesting things did come out of the discussion.

Rick noted that the status of 1.4 GHz used by wireless utility meter reading systems and WMTS regarding primary, co-primary or secondary user status of the frequency is unclear. The FCC is struggling to clear the ambiguity, but until then, managing and registering your frequencies and evaluating the 1.4 GHz band and its local utilization is up to users. It was noted that licensing of 1.4 GHz for wireless meter reading is growing over time.

Rick noted that almost half of the 608 MHz band at MGH is used up by allowable "side lobe interference" from channel 38.

A great question came from the audience asking about 2.4 GHz usage, and how much is too much; the answer is no one knows. With proper planning, design, and installation combined with advances in technology we may never reach a saturation point in the 2.4 GHz band. As a related benchmark, Cisco recommends no more than 12 devices per access point for networks supporting wireless VoIP phones. Capacity of wireless devices in a given area is a parameter that most hospitals are not considering sufficiently (if at all) in current WLAN installations. One way to increase support of more devices in a given area is to increase your access point density.

After the session there was some discussion of Guidant's use of 900 MHz for their wireless ICD and programer and the known interference with Spectralink phones and Plantronics headsets - Rick emphasized this was not a "probelm" with anyone's product, but simply an RF management issue not unlike other RF management issues that frequently arise. Yor can read more about this here.

The real takeaway from all these RF discussions is that there is no one best wireless band or technology. Everthing depends on the application, environment and what you're trying to accomplish - and this holds true whether you're a hospital or vendor.