Real Time Locating and Wireless Sensor Networks - Rapid Advances

In the past, too much use of RFID has involved sensing items and conveyances only when they pass very near to the occasional interrogator. Heroic assumptions are then made about what happened in between. Was it destroyed, perhaps by overheating? Is it still there? Is it intact? Dissatisfied with this vagueness, hospitals, manufacturers and others have been rapidly adopting Real Time Locating Systems (RTLS - Second Generation Active RFID) where interrogators sense location in 3D without being nearby. There is even early adoption of Wireless Sensor Networks (WSN). This is Third Generation Active RFID, where the tag doubles as a reader in a self-healing self-organising mesh network, each of these nodes being able to sense not just locate. However, RTLS and WSN tend to need more power at the tag ("node") so energy harvesting is increasingly employed with a rechargeable battery. That will develop into multi-mode energy harvesting with no battery and 20 years life or more, so the tags can be embedded and maintenance free. For example, the Center for Energy Harvesting and Systems at VirginiaTech is developing wireless self-powered sensors and actuators.

 

Only IDTechEx stages events that combine RTLS, WSN and Energy Harvesting . Indeed, these are annual events in three continents. Let us look at some practical examples from earlier this year.

Healthcare is a particularly active user. For instance, up to 30,000 blood and tissue samples arrive daily for examination at the Medical Care Center of Dr. Stein & Kollegen, headquartered in Moenchengladbach, Germany. The medical samples are transported from various physicians' offices, hospitals and other laboratories in approximately 600 special transport containers. Particular attention must be paid to shipping as temperature fluctuations can cause the transported samples to be unusable. As a result, the Medical Care Center laboratory deployed a WSN that simplifies existing processes and provides a reliable quality assurance tool. Identec Solutions and PCO had active transponders provide specific track and temperature monitoring. An alarm system forwards an error message in an electronic form to supervising personnel. For example, if they receive solvent for analysis, and during transport the predetermined temperature limits were not strictly adhered to, all samples are often unusable. The negative financial consequences of damaged samples as well as the challenge of dealing with lost or missing deliveries are now addressed with the WSN system . Further benefit was achieved by eliminating the significant human resource burden previously required with tracking shipments.

 

 

Bamberg Hospital and Universitats Klinikum in Germany are monitoring both blood and patients with a full WSN system installed by a Fraunhofer institute. It gives the location of blood and matches it to the patient in these hospitals. The batteries last 2.5 years, which is quite good for WSN, yet far from ideal. Affordable, longer-lived energy harvesting is sought that is not too big or heavy.

Reva Systems has deployed RTLS equipment at the new Roy and Patricia Disney Family Cancer Center in Burbank, California USA. This reduces patient anxiety and improves the workflow between clinicians, patients and administrators. It deploys a comprehensive, integrated RFID solution where the readers relay information from low profile passive RFID tags - located, for example, on a patient ID badge - to centralized applications that retrieve patient information in order to enhance the patient experience. This information includes patient preferences to activate custom hospital room settings - music, lighting, temperature, etc. - and location data that are sent to staff phone displays, allowing clinicians to greet or locate patients quickly.

 

 

On the other hand, San Joaquin Community Hospital in California has installed the Skytron Asset Manager system using Awarepoint's technology and server. Previously, when employees met for their daily bed-meetings, the nursing staff often wasted time searching for IV pumps or a bed, and patients were sometimes left waiting. The Awarepoint interrogators plug into power outlets, and transmit and receive information to active RFID tags attached to assets. A server manages that data, and can be accessed via the Internet. Initially, Skytron installed 350 sensors throughout the hospital's 255-bed facility. RFID tags were attached to the hospital's IV pumps, beds, wheelchairs, pacemakers, speech amplifiers and other items. The facility is also tagging its rental equipment until each item leaves the facility, when the tag is removed and placed on another asset.

India's leading systems integrator ICEGEIN has deployed Ekahau RTLS at Apollo Hospital Chennai. The hospital tracks patients having various tests done as part of their annual check-up, in order to better utilize hospital resources and shorten patient wait times. Each day the hospital offers annual comprehensive health checks for 200 patients, which require them to visit a number of departments - such as cardiology, imaging and the laboratory. Because these patients move from one place to another frequently during the process, it is hard to monitor which department is busy and which one has no wait, or whether a patient is in the right place at the right time. The system solves this.

Identec Solutions is installing its newly released IntelliFIND Real Time Locating System (RTLS) for the ship to shore crane and yard operations of Total Terminal International Algeciras (TTI ALGECIRAS) for deployment at the new Greenfield automated terminal in Algeciras, Spain. ABB will provide the total solution and support systems, with a Terminal Operating System developed by Korean company Cyberlogitec Ltd.

Ubisense and Verkehrsautomatisierung Berlin (VAB) have installed RTLS at two depots for JNVG mbH (Jena Transit Authority) enabling efficient management of Jena's fleet of buses and trams. Initially, it monitored 80 vehicles belonging to JNVG mbH. Location tracking for an additional 30 vehicles, owned by another organisation, and housed at the JNVG mbH depot, were added later. Accurate to one meter, the system spans buildings and a parking area. This positioning allows vehicles to be assigned to a particular track or parking place. The RTLS supplies information for the VAB depot management system, providing alerts when vehicles arrive or leave the depot. Informed decision making, and efficient process optimisation is the result.

 

 

Airbus has also selected Ubisense for precise RTLS at multiple Airbus facilities. Ubisense location solutions will provide Airbus with a real-time view of business operations such as the tracking of components and assembly processes thus aiding communication, process improvement and planning activities.

So what comes next? At the IDTechEx joint event Wireless Sensor Networks & RTLS USA and Energy Harvesting USA (www.IDTechEx.com/Boston ), in Boston Massachusetts November 16-17, even more remarkable advances will be announced for the first time. Rockwell Collins and the $20 billion French electrical goods manufacturer Schneider Electric will present on WSN and RTLS installations as will Lockheed Martin subsidiary Savi Technology, National Instruments, Emerson and Dust Networks that have remarkable advances to report. Progress towards the necessary energy harvesting will reveal surprising virtuousity. The University of Tokyo is working on high performance polymer electrets for vibration harvesting, Trophos Energy has bioelectrochemical systems and Voltree Power can harvest biochemical energy from trees. After all, wireless sensing will be used in and on the human body - Tagsense reports on wireless diagnostic patches at the event. WSN will be on billions of trees in forests and in a host of other very different applications. Massachusetts Institute of Technology reports on thermoelectric harvesting - useful for wireless sensors embedded in engines and buildings. Piezoelectric, solar, RF beam and other harvesting will be covered by several speakers and exhibitors such as PowerCast. Indeed, the use of several modes of harvesting in one device will be covered by Microstrain and IDTechEx. This remarkable event will include Masterclasses before and after the two day conference and exhibition and visits to local centers of excellence. For full details visit www.IDTechEx.com/Boston .