The group pushing for dedicated RF spectrum for wireless
sensors has yet to provide data justifying their request. Their
current rationale is based on anecdotal scenarios resulting from
intentional interference from devices using the same frequency.
What hard data does Philips or GE have to offer that show's that
hospital Wi-Fi networks are "full" or "being filled up?"
Not mentioned is the fact that much of the interference that
disrupts wireless communications in health care comes from
unintentional sources - often things like failing electrical
motors and florescent light ballasts.
While we're told that wireless sensors require their own
spectrum, Wi-Fi and cellular wireless are suggested for use as
"backhaul." At what point is this life critical data no longer life
critical, and no longer in need of dedicated spectrum?
The one reason that so many wireless applications exist in the
ISM band is that the standards used provide for reliable
managed coexistence.
Proponents of this dedicated spectrum do not offer any
mechanism to ensure reliable managed coexistence for wireless
body area networks. Every such system from medical device
manufacturers will be proprietary, and likely to create
coexistence problems of the very sort they say they want to
avoid.
A dedicated band for body area networks will result in higher
costs
Do body area networks deserve their own special frequency band? Even if some rights must be taken from airplanes or national defense?
(The Philips Heartcycle, a sensor-embedded shirt measuring heart functions, was announced last year. Picture from Crunchgear.)
A consortium within Advamed, the medical devices lobby, is presently pushing the FCC to give it rights to 40 MHz of frequency starting at about 2.360 GHz. That’s just below the WiFi frequencies on your digital radio dial.
A decision is expected this summer, with pushback coming from the aeronautics and defense industries, which presently have use of the band. A study of the impact of those waves on the body has also begun.
Paul Coss, director of marketing for critical care, is Philips’ point man on this issue. He said that if the allocation is given, a mass market of implantable and wearable devices could be created, using WiFi or cellular for backhaul, that can save lives and cut costs.
Philips has extensive work underway on body area networks, but only a subset of these applications would need dedicated spectrum, Coss said.
But why dedicated frequency, I asked. Why not take advantage of the current mass market for WiFi radios?
Because, he said, hospitals are already using that band to its maximum. “Hospitals don’t want to put anything else in this space. It compromises paging, phone systems, streaming of digital images around the hospital. By giving us dedicated space we won’t interfere.”
The WiFi band is also being filled up at home, said technical lead Delroy Smith. “You cannot have life-critical events being disrupted by a Gameboy.”
And the top end of this market would definitely be filled with life-critical events. Coss said a dedicated frequency band would allow better monitoring of patients in a hospital, and allow for earlier discharge.
“We’re doing something like this with congestive heart failure patients, where we monitor weight, heart rate, level of oxygen in blood, collected by a device in the home, sent from any broadband. It keeps people from being readmitted.
“If by monitoring these people in the home we can catch them before they get to the tipping point where they need hospitalization, putting them on different fluid pills, you get better care and prevent expensive re-admission.
“But these devices aren’t used on the scale or price point we think we can get to with the inband M-BAND initiative.” (MBAND stands for Medical Body Area Network Device.)
I have been writing about this field since 2003, and quickly asked about non-critical patients, ordinary folks with hypertension or diabetes who might benefit from constant monitoring but don’t need to notify doctors and hospitals until the condition becomes critical.
With a dedicated frequency, a mass market of radios, and systems that can interface with cellphones, there can indeed be an app for that, Coss said. The trick is to get a dedicated frequency and then work with groups like the IEEE 802.15 body to make these international standards on which a global market can be built.
“All the evidence shows people have clear signs, as much as 48 hours ahead, before they get into a bind. If we can intervene in a timely fashion we save lives. The expectation is not just the home environment but everyone in a hospital will have background monitoring, like a check engine light.”
If like me you’ve lost a dear friend or mentor to a “sudden” heart attack, you can see the value. All I can say is godspeed, and you will see more reports on this topic soon.
