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.

4 Comments

1. 1. taylorw 11:41 AM 9/20/09

   This can't possibly be advanced until we reach a serious understanding of the effects of electromagnetism in and around the body. We still can't be sure what the effects of cell phones are. We are just starting to understand the workings of underlying electric properties of cells and DNA. Because MBAN promises the sales of products that have margin and mass quantity, this will be hard to hold back once product development processes get underway.

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2. 2. Reginald_Jensen 04:00 PM 9/21/09

   The device should be adapted to monitoring a person's exercise routine, such as a GPS system. It could record the person's exercise and transmit the results to a computer to be transferred to a central location. Then two classes of medical insurance could be adopted, one for those who exercise (with all costs paid by taxes) and the other for those who don't, with the second group paying the excess costs. People who can't exercise would be included in the first group. Medical costs could be reduced no less than 40% over the $2.4 trillion currently expended.

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3. 3. Deagleson 10:05 AM 9/22/09

   This is truly an amazing use of technology. The concern over the exposure brought up via one of the comments above, I suspect is less of a concern in relation to the value created by the system itself. We are currently exposed to a variety of radio wave technologies within our homes and as pointed out via our use of cell phones. This should be considered, but the fact a sensor can alert doctors and emergency personnel that a problem exists before it becomes life threatening will not only save lives, but it can also greatly cut down on medical expense as a preventative measure. These are the solutions needed to truly allow healthcare to be universal and to create a better quality of life. Early detection and preventative medicine is a critical requirement that this system can enable. Thanks for the article and I hope to see more articles as this program progresses forward.

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4. 4. jwelch 10:01 PM 11/13/09

   With all due respect to my collegues at MGH I do not see the value in yet another failed allocation of precious RF spectrum for medical devices. WMTS was suppose to be an open spectrum that allowed medical devices to "share" the spectrum in a way similar to how ISM devices share the same rf space. The result is a failure. Hospitals must now commit to a single vendor for their medical telemetry systems at enormouse infrastructure cost that essentially locks out innovators. And guess who has been a major benefactor? Not the hospitals or the patients, but the vendors. ISM (aka WiFi) has proved to be just as effective, if not more reliable, and certainly lower price than WMTS. The considerable value of adopting international standards for wireless communications is just that...international. Which means lower costs by leveraging much larger industrial production scales and a worldwide market. An international group proved short range ISM based MPAN radios could reliably connect using off the shelf low powered radios (802.15.4, Zigbee) in the exact architecture suggested in your article. The barrier to making such devices commercially available is not the availability of protected RF spectrum but the lack of insurance reimbursement. Let innovators create affordable, internationally workable solutions on already available and adequate RF spectrum. I hope the FCC is wiser this time around
   
   jimw

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