First up after lunch, "A Prescription for Wireless Anxiety," presented by Scott Bradley of Draeger and Dave Hoglund with Andrew Corp. Scott related his experience on wireless and risk management at Draeger, especially a market study that Drager underwrote this year. For some time, a major portion of their product strategy has been based on the belief that, "the ease of integration of devices with existing health care systems and network infrastructure will be the driving factor determining which devices are adopted and used on these wireless LANs." Here are some additional findings:

  • Multi-functional purpose of networks is accelerating growth of wireless LANs
  • Wireless network priorities: Robust security, Upgrading to 802.11g, Reliability and Quality of Service (QoS)
  • IT Department will “own” shared networks
  • Regulatory certification with specific network hardware
  • “Wireless LAN best-practices” need to be supported by vendors
  • Challenges
    • Device companies need to invest in keeping products current
    • New support issues result from shared networks
    • Integrating products with untested, existing hospital networks

New requirements make deploying medical devices on shared networks, specifically the need to simplify implementation and testing of devices on common network infrastructure through industry-wide best practice. Device vendors need to use device design and development strategies to accelerate new standards and new customer network requirements.

Scott referred to the recent FDA draft guidance on wireless medical devices. Specifically, “FDA believes the more critical the medical device function and information passed via RF technology, the more important it is the wireless connection be robust.” He suggests that ISO 14971 is a great risk management tool for wireless medical devices. Vendors with wireless medical devices should also refer to IEEE 802.15.2 for coexistence risk management and mitigation, and IEC 60601-1-2:2001 describes in detail testing for unintentional electro magnetic interference - the latest draft of this standard is intended for vendors and users. Users are increasingly falling under standards like this because it is only in actual use that certain factors like interference are ultimately experienced and resolved. The draft IEC 80001 is another standard for both vendors and end users, that describes standards for the deployment and support of medical devices in a network - this standard also includes a risk management process.

Next up is Dave Hoglund, representing Andrew Corporation. Dave started with a survey of the many wireless technologies deployed in hospitals. Hospitals are the worst “Multi-Path”environment due age of construction of hospitals and the variety of construction materials and methods. Nothing is standard! Dave's presentation also includes a lot of great reference data on wireless interference, power levels and other technical issues. Dave touched on the perennial hot issue for biomeds, cell phones in hospitals, suggesting the risk is overblown in consideration to the value derived from cellular technology.

Best practices were suggested:

  1. Perform an initial RF survey
  2. Perform periodic RF update surveys
  3. Establish, publish and enforce a "spectrum policy"

An industry issue that Dave mentioned was the indirect distribution channel that network vendors use. Buyers must not only select the best network vendor, but they are also highly dependent on the ability of their VAR (value added reseller) who actually sells, designs and installs the network. Another key point is the importance of having your own tools and using them. In fact, hospitals should have multiple tools in some cases because they do things in different ways, providing a more complete picture of your RF environment.

Questions - bandwidth consumption of wireless medical devices on an 802.11 wireless LAN? 10-20 kilobits per second - relatively low bandwidth utilization, but sensitive to latency.

Question inspired by experience with a smart pump vendor who released their product with only one kind of encryption - not the kind used by the hospital. The vendor took 9 months to reverify and revalidate their product using the new encryption method. Takeaway: vendors need to provide sufficient flexibility and choices so they can conform to customer's network environment.

Suggestion from audience that Biomed could assume responsibility for the wireless LAN. The past approach has been reactive, and the big point of the presentation is to be proactive. Of course, wireless LANs can be monitored from any department or location - even more than one.

Another suggestion is for medical device vendors formulate best practices and submit them to wireless LAN vendors, so they can address new requirements in future versions of the product, and can train their VARs on device vendor's best practices.

The last session of the day was Managing your Wireless Spectrum: Realizing Your Full Potential," presented by Dave Hoglund. In this presentation Dave got deeper into RF best practices. Before you can talk about managing, you have to know what it is you're going to manage. As new wireless applications are adopted - wireless VoIP, patient monitors, alarm notification, point of care barcoding, etc., you must reevaluate your network design - and may need to redesign your network. Dave reviewed wireless technologies with emphasis on things seeing increasing adoption like ZigBee, cell phones and distributed antenna systems (Mobile Access, InnerWireless, Andrew). After a review of unique challenges and requirements for the hospital RF environment, Dave launched in to best practices. The underlying theme here is being proactive.

Another area of focus includes the tools that are used to monitor and manage RF environments. Dave described the basic requirements for a network operations center that would provide planning, monitoring, and trouble resolution for the RF side of networking.

Questions: RF monitoring that extends down to 402 MHz MICS band. Recommendations have been made to Cognio to extend the RF monitoring range of their system. The larger wireless LAN vendors will be building this monitoring capability into their APs.

An IT department trash talked wireless medical devices because their 802.11b radios would pull down the speed of 802.11g clients already on the network. This is true for older APs, but all the current APs support independent speeds for 802.11a and 802.11g clients on the same AP at the same time.

Can you do a lower cost abbreviated site survey with single channel wireless LAN vendors (like Meru or Extricom) or should you do a complete site survey. The recommendation is to do a full RF site survey that covers all the RF spectrum that is in use in a hospital. Consequently, a single channel infrastructure may not result in a lower cost site survey.