Critical Care Plus-FCC Rule Causes Telemetry Quandry for Hospitals

To Switch Frequency Bands, or Not to Switch?

By Don Long

In the medical telemetry sector, it’s been dubbed "the baylor incident." on feb. 27, 1998, much of the patient telemetry in a wing of the Baylor University Medical Center went down, totally blanked out by interference from a local TV station and catching hospital staff completely by surprise.

"What we saw was just solid Channel 9—just solid," says Richard Roa, now Vice President of Engineering for Welch Allyn/Protocol, Beaverton, Ore., but on the scene at Baylor in 1998.

Speaking at a recent meeting of the Georgia Biomedical Instrumentation Society, Roa acknowledged the most important question raised by the incident: "Why didn’t we know it was going to happen?"

His answer: "We found out nobody knew it."

The incident had no tragic consequences, but it did put the industry on notice concerning the potentially fatal results of medical telemetry that could be shut down by something as simple as local TV. The result has been the Federal Communication Commission’s (FCC) recent assignment of new medical channels, which Roa described as "protected bands"—and what he and others at the sessions described as a mixed blessing.

Specifically, the FCC established Wireless Medical Telemetry Service (WMTS), offering three blocks or bandwidths of radio frequency telemetry space. Additionally, telemetry can move to the industrial, scientific, and medical (ISM) spread spectrum at 2.4 GHz frequencies.

The WMTS band gives primary use to medical users; the ISM band does not. The WMTS band comes, however, with "significant restraints," according to Roa. And based on FCC timelines, hospitals must now make crucial decisions about moving to these frequencies. Ven dors, in turn, will be altering their product mixes and marketing strategies to a market demanding both increased sophistication in technology and better guarantees against medical mishaps.

Hospitals and other telemetry users have the option of remaining on the existing, but increasingly threatened, VHF spectrum. But these users will be only those few in isolated areas not threatened by interference. And staying on this spectrum is not an alternative for the vast majority of hospitals in suburban and metropolitan areas, requiring many channels of telemetry. Their systems will be rendered obsolete, forcing new upgrades and installations.

Furthermore, the new WMTS bandwidth "is not a panacea," according to background information presented at the meeting by Welch Allyn/Protocol, since it comes with its own set of limitations. For instance, though medical applications will be the primary users on the system, this offers no guarantee against all interference. Additionally, the new bandwidths are narrow (only 6 MHz wide initially) and likely to be more crowded with medical vendors offering incompatible transmission schemes.

Also, according to the background information, the new FCC ruling "specifies limitations on this band that do not allow nonbiomedical applications such as voice and video"—applications that will be increasingly valuable to hospitals working in reduced-staff, managed care environments.

And the FCC rules do not block "proprietary, non-compatible, and potentially interfering systems within the band. Frequency use will need to be coordinated by third-party network administrators to avoid interference between biomedical devices," according to the backgrounder.

The result is a major dilemma for both health care providers and telemetry manufacturers: On the one hand, "separate systems for each vendor within a hospital will increase cost, system complexity, and potential RF conflicts." On the other hand, "standardizing on a single proprietary system limits the choice of manufacturers for specific clinical applications and impose high conversion costs as communication technologies improve."

The fallout has already begun, with vendors scrambling to offer their solutions as the best, according to Arthur Gasch, who discussed new vendor positioning at an evening gathering of the Georgia group. Gasch is president of Medical Strategic Planning of Lincroft, NJ. Gasch has been encouraging hospitals to take a long-term view of the changes. And he sees growing market share for some smaller sector players that are doing the same.

Specifically, he says hospitals will increasingly turn to companies such as Protocol, Criticare of Waukesha, Wis., and others. Symbol Technology of Holtzville, NY, will offer wireless products operating in the ISM band, at 2.4 Ghz.

Why? Because they are implementing the bi-directional transmission permitted—but not implemented by—any of the major monitoring companies in the WMTS bands. And, Gasch added, the ISM option offers greater scalability and options WMTS can’t offer: voice transmission, easy integration of IEEE 802.11 Wireless Ethernet with the hospital’s IT IEEE 802.3 cabled Ethernet structure. Because of the low power of the ISM devices, the hospital can control the ISM band and restrict it to standards-based devices only, thus avoiding potential interference.

By contrast, Gasch said, larger decided just to retune their existing UHF transmitters, rather than come up with new designs that take full advantage of the WTMS band. This leaves hospitals continuing with major vendors, with very limited choices for products and features they will need in the future."

Gasch said the competition between "the big three and these smaller players forces hospitals to make some hard choices. Hospitals will have to ask, Do I want to wait two to three years and hope those [big] companies come out and offer a fuller-featured, competitive solution that offers me the benefits I need, or go with a smaller company that offers it today?’ "

"If you believe your telemetry is your solution through 2010 and only want to upgrade from UHF—or VHF—to WMTS, and you don’t need bidirectional [transmission], no additional parameters, no voice communication, then the big three companies are an OK solution, Gasch said. But, "if you believe you need the flexibility of patient-worn monitors, bidirectional communications, a nurse talking to the patient, and to other nurses—and not carry four different devices around, but integrate it in one device—ISM-band solutions look like a real winner