Body hammered: very personal area networks

Body Area Networks could one day turn human beings into living networks. E&T gets wired up.

'Everything has to be connected' appears to be the dictum of consumer technology companies - with virtually every new product release now featuring an element of connectivity through the ether making the Internet ubiquitous.

Arguably, it is not just the Internet that devices need to be connected to - they can benefit a great deal from sharing data. This can be easily accomplished in the home or office by all the devices talking to each other via a wireless router.

However, where this connectivity would be very beneficial is on one's person. But as people are a moving target, a wireless network will be problematic.

The advent of Bluetooth open-wireless standard with its low-energy requirement and supposedly simple to set-up architecture was designed to herald an era when our mobile phones would communicate with our laptops, PDAs (remember them?) and other portable devices on-the-fly.

However, Bluetooth primarily works as a cable replacement technology by pairing two devices with each other - a process that has proven to be not-so-simple.

Therefore, for a body area network (BAN) to truly work, it will have to be able to create a robust multi-device capable network technology that will be both secure and easy to set up - something that has eluded the protagonists of enterprise networks and home networks.

The killer app

The first applications using experimental body area networks have been in the medical field - with the BAN used as the base technology for the permanent monitoring and recording of a patient's vital signs, allowing a medical professional to supervise the status of patients suffering from chronic conditions and to provide a form of automated therapy control.

Essentially, the BAN would send information from portable medical devices that would either be worn or exist intravenously inside the patient.

Along with the BAN, these portable devices form a sensor network that could potentially be transmitted to a home base station from which data could be forwarded securely over the Internet.

Since patient data is highly sensitive and the quality of the information could literally mean the difference between life and death, security is high on the agenda. Therefore, robust encryption methods must be integrated in the network's security layer.

It also goes without saying that this information must be uniquely identifiable to avoid any unfortunate mix ups.

BAN systems could also be used in the monitoring of newborns or with the use of wireless hearing aids.

One important requirement for this type of network to work would be little energy use in terms of milliwatts. Other than the advantage of each device being able to operate without needing to replenish its power source, this level of power could easily be scavenged from the immediate environment.

Power scavengers

Researchers are looking to do just this. Last year, Belgium-based IMEC and researchers at the Holst Centre announced the development of a battery-free wireless channel EEG (brain waves monitoring system) powered by a hybrid power supply. The supply consists of a tiny thermoelectric generator that uses the heat dissipated from a person and also has silicon photovoltaic cells. The entire system looks like a pair of headphones.

"The transmit power consumption is an order of magnitude less than Bluetooth or Zigbee," says Bert Gyselinckx, IMEC's programme director for wireless systems.

The EEG system uses IMEC's proprietary ultra-low-power radio chip to extract the signals with micro-power consumption. A digital signal processor encodes the extracted EEG data, which are sent to a PC via a 2.4GHz wireless radio link. The whole thing consumes only 0.8mW.

An even more novel and unusual approach has been taken by researchers at NTT in Japan. Their RedTacton human area networking system uses the surface of the human body as a high-speed network by using the small electric fields emitted.

A network is created when a part of the human body comes into contact with a compatible receiver. The company claims that up to 10Mbps can be transmitted this way.

Surely, transmitting so much data using human skin cannot be safe? According to Hideki Sakamoto, a senior manager at NTT's research and development strategy department in Tokyo, it is completely safe. "The electric field is exceptionally weak and unstable and it cannot cause any harm to the person," he claims.

NTT has been developing RedTacton for a number of years. However, only this year did the company start to develop a serious application using it. In February, NTT RedTacton announced a partnership with Hitachi Systems to integrate the system into building controls in order to authenticate visitors and staff in public buildings.

Since the same electric field could be transmitted to any conductive surface, the company effectively plans to turn human beings into living, breathing swipe cards.

One of the biggest challenges for building BANs is trying to get the devices small enough so that they are discrete and can easily be integrated into clothing, or even inside the human body.

One material that is being looked at is carbon nanotubes to build what the futurologists have dubbed smart dust.

These will be microscopic devices which will have processing capability and will be able to communicate with each other using radio technology.

Devices at this scale would need to scavenge energy from their environment. At the moment, however, these devices still remain in the realms of science-fiction.

Body area network

But what of the lucrative consumer-tech market? Are there any strides to bring this technology to the gadget-crazed masses? Could it become de rigueur for the youth of tomorrow to get totally body-hammered and plugged in?

The nascent wearable electronics trend could be an indication that we are taking the first steps in this direction. Fitness apparel company Nike has sprinted to this conclusion.

The company makes running shoes that can send data about the wearer's performance to an Apple iPod using a wireless system called Nike+.

The wearer is able to get information on time, distance, pace and calories burned through the earphones of the iPod via a sensor in the insole of special shoes that communicate with the digital music player. Consumers can transfer collected data onto the Nike website,

The company also has a line of performance clothing, including jackets and shorts, that holds iPods and keeps wires untangled and out of sight.

"We share the same types of consumers," says Trevor Edwards, Nike's vice-president for global brand management on his company's partnership with Apple

Personal ads

Researchers from the Electronics and Telecomm-unications Research Institute in Korea are said to be developing a way to use body area networks to connect a person to advertising using a process similar to RedTacton to connect with advertising hoardings.

As a user must walk up to and physically touch an electronics poster, the theory is that the ads will only be relevant to that individual. Information collected from the person's mobile phone will be transmitted through the body to decide which commercials to show. Although this idea may appeal to advertisers, for consumers it may raise serious ethical questions.

And this is just one question likely to be raised by consumers, considering the long-running debate about mobile phones and their masts. The idea of using humans themselves as the conduit to transmit information will give some people nightmares.

There is also the issue of security. However secure body area networks are made, there will always be a constant arms race with self-styled 'black hat hackers' whose goal would be to access this information. Where medical data in particular is concerned, security and privacy would be the main worry for consumers.

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