Connecting Medical Devices with Bluetooth and Wi-Fi

Originally Published MDDI March 2002

NEWS & ANALYSIS

Sherrie Conroy

Fewer caregivers and more patients are driving the need for increased device connectivity in hospitals. Both wired and wireless technologies are available to address the need, but two primary technologies—Bluetooth and Wi-Fi (802.11)—are leading the way for wireless devices to connect medical devices and patient information to hospital networks.

According to Tony Costello, director of sales and business development for Red-M (Englewood, CO), "Deploying wireless technologies in hospitals with a low-power solution provides the ability to roam freely and stay connected." The only drawback, said Costello, who was speaking in Anaheim, CA, at the MD&M West 2002 trade show, is that with Bluetooth's low power (1 mW) comes low bandwidth.

"Bluetooth has been heavily hyped and heavily picked on," Costello said, but he added that it has held its own and has been integrated into mobile phones and personal digital assistants (PDAs).

A pilot Bluetooth network program in Germany placed eight Bluetooth access points in patients' rooms and nearby hallways. The access points allow clinicians to move about using PDAs for administrative tasks. "They can carry out their routines in much less time because the PDAs are dynamically synchronized throughout the day," he said.

Costello emphasized that the use of Bluetooth in conjunction with Wi-Fi is possible without the need for two separate networks. Using software to manage the synchronization to the different types of technology enables a hospital to address that challenge efficiently.

"Wi-Fi (802.11b) has driven down the costs of wireless implementation, and [Bluetooth] interoperability is very good," said Lynn Lucas, director of commercial networks business unit at Proxim (Sunnyvale, CA). She said 802.11b, which operates in the 2.4-GHz band, is being used for patient records and monitoring.

Some confusion has arisen in the last year over possible interference between Bluetooth and Wi-Fi, which both operate in the 2.4-GHz industrial, scientific, and medical (ISM) band. "They can happily coexist because they are complementary," Costello said. Each technology is suitable for different uses: Bluetooth for sharing patient information, for example, and 802.11 for corporate hospital information.

These interference issues may disappear completely with 802.11a, the next generation of Wi-Fi. This standard uses the 5-GHz portion of the spectrum. It also uses much higher data rates than 802.11b (54 Mb/sec compared with 11 Mb/sec), and higher throughputs as well (34 Mb/sec compared with ~5 Mb/sec). Lucas believes this increased speed is "an order-of- magnitude leap for wireless." The speed of 802.11a will open new healthcare applications that would be very difficult without the increased throughput. A key benefit, she said, is that 802.11a retains consistently higher data rates as distance from an access point is increased.

"This clean band, which is also unlicensed, means that hospitals won't face interference from microwave ovens, Bluetooth devices, legacy wireless [local-area networks], or cordless phones," she said.

Copyright ©2002 Medical Device & Diagnostic Industry