MEDICAL BODY AREA NETWORKS Sometime within the next few years, doctors will be able to gather info about their patients using networks that pull data from wireless sensors located on and in the human body.
© ANDREI MALOV, COURTESY OF ISTOCKPHOTO.COM

When computers, servers and digital storage devices began to find their way en masse into businesses and homes in the late 1970s and early 80s, industrious users figured out these systems could be linked together into local area networks (LANs) that enabled the rapid exchange of information from machine to machine. Medical technology makers are now hoping to scale this model down to the personal level by connecting wireless sensors placed on (or even under) a patient's skin to create "medical body area networks" (MBANs) that provide doctors with real-time info about their patients.

An MBAN would help hospitals and healthcare clinics better keep tabs on important health-related information, including a patient's temperature, pulse, blood glucose level, blood pressure and respiratory function. Each sensor would communicate information about the patient's body via short-range wireless signals to a small receiver (either handheld or hooked onto a bed or wheelchair) that would use longer-range wireless signals to share that information with the healthcare facility's centralized computer systems—all without the jumble of wires needed to do this today.

As new sensors are developed, these body area networks might even turn into the human equivalent of General Motors OnStar vehicle maintenance services that drivers use to proactively inform them of the need for maintenance and to call for help when lost or in an accident.

Work in Progress
Before this can happen, a lot of work needs to be done developing low-power wireless sensors (that can operate with tiny batteries) and reserving space on the wireless spectrum to ensure this potentially life-critical data has priority status so it can get where it needs to go reliably and securely.

The technologies needed to make MBANs a reality are still being developed, says David Freeman, general manager of the parameters program at GE Healthcare Monitoring Solutions. GE is one of many businesses and research organizations trying to change this by developing the wireless sensors and infrastructure needed for MBANs. Another is Intelesens, a company based in Northern Ireland that develops wireless monitoring technology that uses Bluetooth to deliver medical data from sensors to a short-range receiver and Wi-Fi to send data over even longer distances. Dublin, Ireland-based Realtime Technologies also makes wearable wireless Bluetooth sensors that could be in used as part of an MBAN.

However, using Bluetooth, a wireless communications protocol for mobile phones, laptops and video game consoles, to make body sensor networks "really falls down when it comes to battery issues," says Nathaniel Sims, a physician at Boston's Massachusetts General Hospital and assistant professor of anesthesia at Harvard Medical School.

Bluetooth requires batteries powerful enough to send radio signals between roughly one and 10 meters. An MBAN would encompass a radius of about one meter, so it could use a much smaller battery. Sensors small enough to work effectively as part of a MBAN might not have the size needed to carry a battery powerful enough to operate a Bluetooth radio for any significant length of time (without completely sapping the battery).

Batteries aside, another hurdle could be a lack of bandwidth, says Rick Hampton, wireless communications manager for Partners Healthcare System in Boston. "What everyone is looking for is an area of the spectrum that's relatively secure and that can handle the bandwidth of all the new [wireless monitoring] devices that will come online," he says.