The deaths of six Worcester (Mass.) firefighters in an inferno at a vacant six-story warehouse on Dec. 3, 1999, generated a pledge from faculty in the electrical and computer engineering department at Worcester Polytechnic Institute to apply their expertise to develop a system to find firefighters in similar hazardous situations.
“I think if you had asked anybody then, they would have said, ‘OK, if we throw some technology at this, we’re going to have a great location tracking system for indoor use in maybe three or four years,'” said WPI Associate Professor James Duckworth. “The truth is, it’s eight years later and we still don’t have anything deployed.”
Nevertheless, he and his associates, as well as researchers elsewhere, appear to be getting very close. A range of prototypes and products were demonstrated and discussed during a conference at WPI in August, and some developers put their equipment through tests conducted by the Worcester Fire Department in a multi-story cement and steel building where global positioning systems are ineffective.
“It was actually a very challenging environment,” Duckworth said. “Some of the systems had radio problems, and some of them actually lost some of their reference signals so they didn’t actually know where people were. So there were a few wrinkles.”
One aspect of WPI’s research is to develop a wireless system for incident commanders to monitor the vital signs of firefighters on the fire ground with the aim of preventing deaths due to stress and overexertion. That system – called physiological status monitoring (PSM) – was tested at WPI in August, is scheduled for beta testing by other fire departments over the next 18 months and should be commercially available within two years, according to Mark Mordecai, the director of business development for Globe Manufacturing, a leading producer of personal protective equipment.
Globe and Foster-Miller, Inc., a Massachusetts technology and product development firm, have been working in partnership with WPI, supported with funding from the Federal Emergency Management Agency.
“The objective,” Mordecai said, “has been to integrate spatial 3-D indoor locations with physiological status monitoring and to develop a single mechanism and graphical user interface to get that signal out of the building and make an incident commander aware of two issues: where am I and how am I. Clearly that’s kind of a Holy Grail.”
The PSM system, he said, uses a “a technical T-shirt” that would be fire resistant and moisture wicking and incorporate sensors to monitor such factors as heart rate, respiration rate and skin temperature. He said the system would also “incorporate some inertial issues about how much work you’re doing and be able to take that signal and transmit it through a short range radio to a real radio that’s going to get that signal out of the building.”
Since the PSM piece of the project is expected to be workable before the 3-D locator part, he said it will be the first to be made available to the fire service. He estimated the locator system would be ready within three years – about a year after physiological status monitoring.
Mordecai said participants at the August conference found a number of areas of agreement, among them that the development of a 3-D system would be not be achieved by any single technology. It requires a “cocktail” approach, he said, “a mix of technologies so that each will be able to help make the positioning more accurate.”
Another point of agreement, he said, was that products will be rolled out piecemeal. “People felt it was important to deploy the pieces of the technology that would make a difference in a significant number of cases rather than waiting for it to be perfect so that it would work in all cases,” he said.
One of the challenges for researchers is how to transmit physiological and location data on firefighters out of a building to incident commanders.
“The limitations of a radio signal is a serious issue, but getting it to work in most cases seems to be practical with today’s technology,” Mordecai said. “It’s the same problem that firefighters are facing with their current radios, that there are some structures where they’re not getting radio communications.”
The ability to transmit voice or data depends to some extent on the construction of a building. “It may work fine in some locations and sporadically in others and not at all reliability in others,” he said. “But in a high percentage of the buildings that are typically involved, there’s little question that a system will be able to get the information outside of the building.”
WPI’s research and development effort is called the Precision Personnel Locator Project, and this year’s conference, called PPL Workshop 2008, was the third in three years hosted by the school. Duckworth is the principal investigator on the project, as well as the chair of the three-day conference, which was designed as a forum to share technical knowledge about indoor location and tracking of emergency responders. It was the first to offer system testing.
The conference drew more than 100 participants, primarily researchers and engineers representing universities and companies developing systems, as well as companies with products already on the market. Also attending were representatives of government agencies funding the research and firefighters.
“Everybody reported that it was a fantastic learning experience. Some of the developers had not really appreciated what the firefighters do under realistic scenarios,” Duckworth said. “It was a real good shakeout, being evaluated by the actual first responders themselves.” He said the Worcester Fire Department deserved a lot of credit for the success of the conference.
A range of different types of systems were discussed and demonstrated, but only five were subjected to testing, which frustrated a number of people, among them Duckworth, Mordecai and Worcester District Fire Chief John Sullivan, who served as incident commander for the tests.
“Some of the participants chose not to participate in the testing and that included some that at least on their presentations looked very promising,” Sullivan said. “There was a lot of discussion about intellectual property rights and things that, as a firefighter, just tick you off.”
He noted the purpose of the conference was to share information to help develop effective systems to save lives. “I congratulated the folks who put themselves out there [for testing] and opened themselves to the criticism that inevitably will come when you’re in this portion of the research,” Sullivan said. “And to the others I said, ‘Shame on you. Shame on you.'”
Duckworth said government representatives were also disappointed that some developers were reluctant to put their systems through a test. “WPI and others were prepared to take a big risk and gamble to see how it would work under realistic conditions,” he said. “We were prepared to have all the warts on visible display so everyone would learn from the experience.”
Indeed, imperfections were exposed for every system tested.
The site of the testing was an academic building on the WPI campus that was regarded as a difficult proving ground because of its layout and its steel and cement construction. Worcester firefighters played a large role in the planning and execution.
The scenario involved a fire attack team that because of worsening conditions was forced to evacuate the building. When the team got out, one member was missing. Other rescue teams of firefighters were deployed to locate and rescue the firefighter, each using a different type of system. The search path was about 175 feet with many turns and a long stairway to the second floor. Rescue teams crawled and wore masks to simulate a smoke-filled atmosphere.
3-D Locator Systems
Five systems were tested:
- Two were 3-D locator systems that use graphic displays on laptop computers to keep track of the movements of firefighters from an incident command post.
- Three were tracking systems for rescuers, handheld devices that seek out signals emitted from transmitters carried by firefighters in trouble.
“We work out how long it takes for the radio signals to propagate to the receivers and by looking at the time difference of arrivals we can pinpoint where the individuals are,” Duckworth said.
The other 3-D locator is called the Mobile Response Command System (MRCS) and is under development by two companies, Rex Systems, Inc., an electronics company in Chippewa Falls, Wis., and ENSCO, Inc., a high-tech firm in Falls Church, Va.
Development of the MRCS has been funded by the U.S. Army. In a presentation at the WPI conference, representatives of the companies said their objective was to provide an effective tracking and positioning system that meets the needs of military and civilian first responders in GPS-denied environments.
The MRCS uses a heel-mounted, low-cost inertial measurement unit with an integrated magnetic compass to provide real-time position data to both the firefighter and incident command.
Detailed results of the individual tests and evaluations by firefighters were not released, but WPI did issue an overall report on the testing last month.
Regarding the 3-D system tests, the report said, “The new technology allowed the search team to make all the right moves and locate the victim in a shorter time than classical techniques.”
Both of the 3-D locator systems “provided significant location capability, even though each had ‘technical difficulties,'” according to the report. Overall, it said, “The firefighters were pleased with the progress and the prospect for production systems of this caliber in the future.”
After the 3-D systems, the three tracking systems were put to the test.
One of those is another prototype developed by WPI called the Mantenna homing device, which uses a highly-directional antenna to trace radio waves transmitted from a firefighter who is lost or in trouble.
“It’s like a Geiger counter,” said WPI Professor David Cyganski, who invented the Mantenna. “If you are pointing in the right direction you get lots of clicks and if you’re pointing in the wrong direction you get very few. You simply follow the sound as it gets higher and louder.”
As the device gets closer to its objective, he said the clicks become a buzz that works its way up the tonal scale until it becomes a pulsing wail when the transmitter on the firefighter is within reach.
But sound is not the only indicator. The Mantenna also has a color bar of very bright lights, Cyganski said, that move from cool to hot as it gets closer to its target. In addition, he said, the sounds and lights are mimicked by vibrations in the device to indicate direction and range.
“So depending on which of your senses is working best at the time,” he said, “you have some way of knowing that it’s responding.”
The other two tracking systems tested by Worcester firefighters are commercially available. One is the Pathfinder made by Summit Safety, Inc., which has licensed three SCBA manufacturers to use its product – Sperian, Avon-ISI and Interspiro. The other is the Dräger Tracker FRT 1000.
Summit Safety, located near Worcester, was created by Wayne Haase, after the tragic 1999 Worcester warehouse fire. Haase is president of Summit Safety and has a background in medical imaging. His son was also involved in formation of the company.
“We had been looking at the use of ultrasound prior to that fire,” Haase said. “After the fire we talked about whether the technology we were working on could have made a difference, and we decided the whole business of trying to find somebody in a fire was an area where we really ought to focus.”
The Pathfinder, which was introduced in 2004, uses ultrasound to find beacons integrated into SCBA, as well as beacons placed by firefighters as an “electronic rope” to signal exit routes.
“What’s unique about sound compared to all the other wave mechanisms is that sound does not propagate through walls or floors. It has to go around objects,” Haase said. “Some of it goes out through the door, down the hallway, around the corner and so on. What we realized is if we put an acoustic system on a firefighter, then you’re able to figure out where the walls are and you can figure out how to navigate the maze. The strongest signal is always the shortest path.”
The Pathfinder has an LED bar graph that displays the strength of the signal as the device is moved to scan an area.
Haase said the Pathfinder has been demonstrated and tested in hundreds of settings, and he rated the WPI test as among the most difficult. He said the Pathfinder’s range has been extended since it was introduced, and Summit’s latest improvement is to integrate it with a thermal imager. “It gives the firefighter the eyes with the camera,” he said.
The Dräger Tracker FRT 1000 is a low-frequency radio wave transmitter-receiver that is not deflected by walls or ceilings or other obstacles. The digital display shows distance to a missing colleague in meters.
The company also offers the ETR 1000, an egress transmitter that can be placed by firefighters as an “electronic breadcrumb” to mark exit routes.
Dräger’s system is manufactured through an exclusive agreement signed early this year with Exit Technologies of Boulder, Colo., which created it for avalanche rescue.
“It has audio and visual indicators that let you know you’re getting close,” said Greg Sesny, Dräger’s product manager for the FRT 1000 and the ETR 1000. “The beeps get closer together and higher pitched, and the [distance] numbers go down.”
Because the system can detect signals through walls and floors, he said, it is effective for perimeter searches. During the WPI test, he said, he gave Trackers to two firefighters to conduct a search from outside the building while the primary team was searching inside for the missing firefighter.
“Within a minute and a half [the outside team] was able to locate which side of the building he was on and that he was on the second story,” Sesny said. “The firefighters told me that if it was a real scenario, they would have grabbed a ladder, broken the second story window and gone in that way.”
WPI’s test report said each of the three tracking systems yielded positive results, but all had different advantages and disadvantages.
“Dedicated training on each device by the firefighters would be required in order to provide a fair test of their comparative capabilities,” the report said. “The homing devices are either near term or in fact available products, offering an interim solution sooner than locator systems will be available.”
The Cocktail Solution
Overall, the report summarized what it termed the “state of the art” for location systems this way: “Technologies that are maturing in research need to be combined effectively (the cocktail solution) and delivered through a rigorous product development process as a solution to this difficult problem.”
Following each of the five tests, Sullivan said an official from the Department of Homeland Security, which is funding some of the research and development, asked the Worcester firefighters who used the devices whether they would buy them if they were available. The answer in each case was no.
“For the people who were doing this demonstration and using the equipment, not one was ready yet, even the ones that are actually commercially available now,” Sullivan said.
Regarding the tracking systems, he said the firefighters thought some were close to being ready. “The WPI one, which was a very big cumbersome piece of equipment the way that they have it designed now, actually worked fairly well,” he said.
Cyganski, the Mantenna’s inventor, said he is moving into the “miniaturization phase” of development for the device. “Basically it will be able to fit into something like an axe handle,” he said, “and we may turn it into a multi-purpose tool.”
Sullivan said he believes effective tracking and location systems are less than two years away. “Just the fact that the researchers are working on a problem specifically for the fire service right now is very encouraging,” he said.
He said he is most interested in progress on the physiological front.
“I believe the physiological data gathering will save many, many, many more lives than the actual tracking capability will save,” he said. “We need to make that mandatory, not just on the fire ground, but for an hour or two or whatever the experts say is that critical time frame after the fire where we see firefighters come back and the adrenaline moves through the system and all of a sudden you come upstairs and you find the fire captain in his office slumped over his desk two hours later.”
Globe, according to Mordecai, has been surveying firefighters at trade shows about their willingness to wear PPE with sensors and a one-pound radio that would transmit their vital signs to incident command: “We found a very high percentage of the firefighters at every level are willing to adopt this kind of technology if it functions for them, 85 to 95 percent.”
There is no doubt, he said, that the PPE of the future is going to be far more sophisticated than the ensembles of today.
“Moisture wicking and moisture management is critically important to keep the firefighter’s skin dry and to move moisture through the system,” he said. “And we think down the road there will be multiple layers that will have different levels of intelligence that are going to add a lot of information. Rather than just be a protective envelope it will also be able to collect data and be informative.”
He noted the grim statistics that roughly 100-plus on-duty firefighters die each year and 45 to 50 percent of those deaths are due to stress and overexertion.
“If we can make a difference in some of those by deploying this new technology, that would be some major progress,” he said. “That’s really the goal here, to get to the root cause of those on-duty deaths and see if we can prevent some of them instead of just analyzing them after the fact.”