By Arthur W. Astrin
Wireless body area networks are predicted to proliferate in the next five years and have numerous groundbreaking applications, particularly in healthcare. In order for them to be effective, they must be able to work both around and within the human body. The IEEE 802.15.6™-2012 standard addresses security, reliability, low power, quality of service, data rate and interference protection so these wireless devices and sensors can be deployed in a large scale for medical, sports and entertainment purposes.
Wireless, implantable devices, once the sole domain of science fiction, hold great promise for health-related applications, as well as personal entertainment, but in order for the next generation of these intelligent devices to function effectively, they must be able to handle the effects of the human body on network performance and continue to deliver a high degree of data communications. It is highly unlikely that one vendor will be able to supply all the body devices needed by individual patients. Having many companies involved in the standard development will hopefully enable multivendor operation of body area network devices.
This is where the IEEE 802.15.6-2012 standard comes into play. Introduced last year by the IEEE Standards Association, it is optimized to serve the wireless communications needs for ultra-low power devices operating either inside or around the human body and is a critical component towards the development of new implantable devices and wearable computers. These “body area networks” have the potential to revolutionize healthcare while supporting other innovative applications in sports and entertainment.
Body area networks have some distinct features and requirements compared to other wireless networks. Because of their proximity to the body, electromagnetic pollution must be kept extremely low, which means devices should have a low transmit power. They also have a special network topology influenced by the human body, while wearable devices must be lightweight and non-intrusive.
Also body area network devices by their nature will be mobile with their users and in crowded conditions they may interfere with each other. The standard provides many coexistence features to enable smooth operation in tight quarters, such as elevators, public transportation, hospital rooms, etc. Because these devices may communicate medical information, a lot of effort went into security provisions of the standard.
The IEEE 802.15.6-2012 standard had to support a combination of requirements: security, reliability, low power, quality of service, data rate and interference protection. It addresses a wide range of network applications not covered by other wireless communication standards. With data rates of up to 10 Mbps, the IEEE 802.15.6-2012 standard specifies a low power, short range and reliable wireless communication protocol for use in close proximity to, or inside, a human body. Body area networks have the potential for wide-ranging applications that echo technology seen in movies and television series such as Star Trek. Prosthetics and implants that improve healthcare delivery are no longer sketches on a drawing board: They can be realized in the real world, not only for medical purposes but also for a variety of novel consumer uses. Applications already being served by the IEEE 802.15.6-2012 standard include electroencephalograms (EEGs), electrocardiograms (ECGs) and monitoring of vital signals such as heart rate, oxygen, temperature and blood pressure, primarily in hospital settings.
Like most organizations, hospitals are faced with increased network traffic thanks to a growth in wireless devices such as smartphones and tablets. However, a decision by the FCC late last year will help alleviate the pressure on hospital WiFi: it has set aside 40 MHz of protected spectrum in the 2360-2400 MHz band specifically for wireless medical devices or “medical body area networks” (MBANs). The 2360-2390MHz frequency range is available on a secondary basis, but is restricted to indoor operation at health-care facilities. This dedicated spectrum should enable a broader range of high performance medical applications to be delivered without the potential interference problems normally associated with Wi-Fi and other high-powered devices used in hospitals. China has also allocated spectrum for medical use and IEEE802 is now working on adding that capability to its standards.
A report recently released by ABI Research projects that while the market for what it calls “disposable MBAN sensors” in professional healthcare is in its infancy, there is tremendous opportunity for adoption and that 5 million of these sensors will have shipped by 2018.
But wearable monitoring devices are just the tip of the iceberg: Wireless devices that can be implanted could be used to create automated drug delivery systems for the treatment of chronic conditions such diabetes, removing the hassle of regular insulin injection by implanting a glucose sensor with an insulin pump. Diseases such as Parkinson’s could be managed with deep brain or cortical stimulators. Prosthetics could be controlled by implanting devices to detect nerve signals in the stump or in the brain. That is actually starting to happen today as described in the April 2013 issue of IEEE Spectrum Magazine. Communications was one of the big problems to be solved. While the team was able to secure shared spectrum to facilitate communication, that combined with the further attributes of 802.15.6 would likely result in the ability to move to higher levels of performance as these systems evolve. And if you want talk about technology from the final frontier, how about retinal implants that could give vision to the blind?
Outside of advanced healthcare applications wireless body area networks have numerous uses in sports for monitoring performance and for enhancing electronic game play. Google Glass is one of the most high profile examples of how these sensors could be used in the real world.
Regardless of how they are employed, these wireless devices need to interoperate with each other without having a negative impact on the human body and other equipment. The IEEE 802.15.6 standard makes this possible.
Arthur W. Astrin received the Ph.D. E.E. from U.C.L.A. in Communication Engineering in 1984 and Master Degree in Mathematics from U.C. San Diego. He chaired the Body Area Network Task Group 6 of IEEE 802.15. Dr. Astrin is a recipient of the IEEE Third Millennium Medal and a Senior Member of IEEE. Read more