From the August 2001 Issue

Winning With Wireless

Avoiding the shock of the unplugged world.

By Stephen Hannah, vice president of engineering for VitalCom, a Data Critical company, Tustin, CA.

When multiple problems compete for attention, the old adage recommends taking them ãone at a time.ä But in the case of a hospitalâs wireless systems, implementing solutions one by one÷without a guiding enterprise-wide strategy÷can cause even more headaches. Just imagine how it might happen.

Doctors need instant information about their patients, even when they are in the cafeteria, so the telecommunications department installs an in-house wireless telephone system. Then in med/surg, the information systems (IS) department rolls out the new wireless charting terminals for the Healthcare Information System (HIS) that nurses will use to do online charting at the bedside. Over in telemetry, the biomeds are installing a wireless local area network (LAN) connection to their patient monitors and are asking for IS support.

It isnât long before the complaints begin. The wireless charting LAN does not interoperate with the patient monitoring wireless LAN, requiring IS to support two different infrastructures. These systems are also incompatible with the in-house phone system, causing performance degradation across all three systems. IS doesnât have the manpower to maintain so many different wireless systems, and problem-resolution time skyrockets. In the end, the hospital enterprise becomes an archipelago of isolated islands of information that canât communicate with each other.

Islands of Communication

Any chief information officer understands the challenge of managing the smorgasbord of technology in a hospital. Wireless systems increase the level of complexity. Most wireless systems are designed as ãpoint solutions,ä meaning they address a particular problem or task. Wireless charting systems, telemetry and cell phones are used by different people for different reasons.

While each seems like an appropriate solution and addresses the concern at hand, each also requires its own wireless networking infrastructure. Moreover, the systems often donât interoperate, or worse, interfere with each other, potentially causing dropped signals in telemetry, loss of critical data in the charting system and phone system downtime, not to mention frustration among the caregivers using these systems. In effect, the incompatibilities isolate users from one another, creating new communication problems. Additionally, as the number of wireless solutions proliferates, central management becomes increasingly unachievable.

Enterprise-wide Approach

An enterprise-wide wireless strategy can help prevent department isolation÷islands of communication÷in an unplugged world. It is essential to involve the end users of the systems when creating a plan, as well as the support team. For example, the planning team for a wireless patient monitoring system should include representatives from clinical engineering, information systems, telecommunications, nursing, physicians and operations.

The goal is to determine the overarching requirements for achieving long-term, enterprise-wide wireless integration. This strategy will serve as the rules of the road for each department, guiding them in selecting appropriate and compatible wireless technology. Wireless infrastructure design is often dictated by the demands of the most critical systems, such as patient telemetry and telecommunications, which require high availability since they are used for real-time communication of patient vital signs and staff communications. Ancillary systems like wireless data entry terminals for HIS charting can share the backbone that supports critical systems. It is very difficult, however, to add critical systems to an infrastructure that is not designed for high availability.

Road to Integration

With an integration road map, the planning team can identify mutual needs and select a common infrastructure that supports multiple critical wireless systems. Obviously, each department participating in the wireless planning will have unique requirements and key issues. It is essential to understand and accommodate these issues. Number one priority for nursing may be system speed, while telemetryâs main concern is availability. Other requirements that ultimately drive the wireless infra- structure design are: range of coverage, individual application throughput needs, security, RF interference, number of simultaneous users and scheduled downtime.

Selected technologies may differ from department to department; however, they should all be network compatible. The goal is to apply consistent integration criteria to the selection of wireless systems so that all operate under a common management structure, thereby enabling consistent methods for maintenance and operation. With an eye toward enterprise integration, systems like patient telemetry, wireless charting and telecommunications can peacefully coexist.

Wire-free at Last

Once the enterprise requirements have been defined, the next step involves establishing priorities for integration. First priority is choosing a platform that supports future enterprise communication needs. In other words, a hospital may only require 50 telemetry channels today, but anticipates doubling that in two years and expanding to areas not currently wired-up. Make sure the wireless systems selected can adapt and grow in accordance with the hospitalâs needs and trends.

Second priority is tying together islands of communication. This begins with selecting compatible technologies, but may also require expanded networking bandwidth to satisfy usersâ demands for speed and functionality. Third, ensure that system availability is sufficient for mission-critical systems that cannot afford scheduled downtime or interruptions in service. Above all, consider only solutions that can be integrated into a common enterprise network and lend themselves to central management and control. This may include interoperable wireless LAN systems, micro-cellular wireless medical telemetry service (WMTS) and voice-over-IP telecommunications equipment.

Finally, it is important not to confuse standards with interoperability. Many wireless solutions claim to adhere to standards, but wireless interoperability is rare across competing vendors, even in ãstandardä systems. Counting on different 802.11b wireless LAN systems to interoperate÷such as one vendorâs access points and another vendorâs PC card in a port- able computer÷is usually a futile exercise. Instead, it is optimal if integration is done at the network interface level where networking standards are typically more stable and interoperable. Standardizing on one wireless LAN that best matches the enterpriseâs overall requirements will achieve the highest degree of integration and central management with the least amount of effort.

Protecting Your Investment

With the introduction of the protected WMTS medical frequency band, hospitals have a unique opportunity to evaluate their long-term enterprise-wide wireless needs as they begin their transition to the new spectrum. Address the total wireless system requirements of the hospital to create an integration roadmap that can guide wireless system evolution over time. Prioritize those system requirements and add solutions incrementally, without risk of invalidating previous investments or implementations. Ultimately, an enterprise wireless strategy offers protection from interference today and creates a platform for the future growth of wireless communications.

Keys to Wireless Success

Identify the primary areas affected by wireless systems:

In-house communications systems (phones, pagers)
Data access and entry systems (order entry, charting)
Telemetry systems (patient monitoring)

Identify network infrastructure needs and design drivers:

Do you require high availability?
What range of coverage is needed?
How much throughput is required?
What are your security requirements?
What is the potential for RF interference?
How many simultaneous users are you planning on?
Can you afford scheduled downtime?

Establish priorities for integration

Choose an infrastructure that anticipates future needs.
Tie together islands of communication.
Insure sufficient throughput for mission critical systems.
Choose solutions that integrate into the infrastructure.

Use standards appropriately

Donât confuse standards with interoperability.
Control the integration
Manage RF spectrum allocation.
Manage controlled change and growth.