Wireless sensors make their presence felt

Volkswagen uses sensor software from IBM to track car components

As many as 400 million wireless sensors could be worn by people worldwide in five years’ time.

Until recently, few could have predicted the extent to which wireless technology would find its way into so many aspects of our lives, and in some cases even our bodies.

Many industries, from retail and manufacturing to healthcare and aeronautics, employ wireless sensors in a variety of roles, with data captured and stored on some form of electronic tag then transmitted wirelessly for tracking, monitoring, records update and communications purposes.

Car maker Volkswagen, for example, is using IBM sensor software to access information on RFID-tagged shipping containers used to transport parts from suppliers to manufacturing facilities. Information embedded in the containers is routinely collected at various points along the supply chain and during storage, collection and installation on the assembly line. The benefit is in removing the need for paper documents and barcode labels and tightening up supply chain monitoring, according to the car maker.

Rival BMW recently installed a track-and-trace system at its UK vehicle distribution centre in South Yorkshire, which labels cars or motorbikes entering the 3km-long facility for inspection with an indelible barcode label. This allows information including a unique vehicle identification number and location details to be read using handheld PCs, and transmitted over a Wi-Fi network to a central database that can be accessed to precisely plot a vehicle’s whereabouts within the centre.

Lower power, low-bandwidth wireless technologies such as Bluetooth and Zigbee are commonly used in e-health applications, though cellular technologies such as GSM and 3G are also finding a place in some hospitals and health trusts.

Some large hospitals already tag patients, as well as beds and other equipment, with real-time wireless monitoring systems that help them keep track of their location. But a new generation of wearable wireless sensors, designed to help healthcare providers improve treatment by measuring patient body parameters and communicating that data to remote central systems, is also starting to emerge.

So-called body sensor networks are able to send back physiological data about heart rate, ECG readings, blood pressure and blood oxygen saturation levels, for example. Some manufacturers have even developed pills that monitor core body temperature and send back the information from the stomach to a waist unit via RFID.

Figures published by ABI Research in July suggest that the number of wearable wireless sensors in use worldwide could reach 400 million by 2014, mainly in the professional and home healthcare markets, but also in the sports and fitness industries.

But it is still relatively early days for the use of this technology for critical applications, with a lack of standardisation proving a worrying issue for many would-be adopters. Luke Thomas, programme manager for ICT Europe at analyst Frost, warned that companies need to be careful about using wireless technologies in unlicensed wavebands because of quality of service and security issues.

“There is a lot of development around telemedicine, from electronic health cards to e-prescriptions, but there are standardisation issues to be resolved as well as security and confidentiality problems with patient information crossing the internet and country boundaries,” he said.

Sensors provide early warning of aircraft faults
Another innovative use of wireless sensor networks is in aircraft safety. Engineers at Scotland’s Institute for System Level Integration (iSLI) are developing a wireless sensor system called Witnesss, which is intended to monitor critical components of commercial aircraft to improve safety and maintenance.

“Rather than just taking the aircraft into the hangar for its six-month service we can first get an idea of whether it needs a service, or get an early warning if something might be about to go wrong,” said Mark Begbie, iSLI director. “We could record peak hydraulic sessions in landing gear for example, or look for acoustic events that might indicate some sort of impact.”

The volume and type of data that can be transmitted will depend on the amount of bandwidth made available by the underlying wireless network. Begbie’s aim is to make the software system-agnostic as far as wireless broadband hardware goes, so that support for different technologies can be added on demand.

He admits that full commercial implementations of wireless sensor networks are still few and far between, and that standardisation and accreditation can be an issue, not least from a cost perspective.

The Witnesss system can also be applied to renewable energy, monitoring the status of offshore wind turbines and other equipment.

“One of our aims is to create a system that allows you to monitor its health and the extent of its function change over time, so there is a lot of commonality in other economic structures, including offshore wave installations and other areas of the renewable energy sector,” said Begbie.